JP2003189183A - Imaging device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the image quality and function of an image pickup apparatus using a CCD that is also used for a still image and a moving image. SOLUTION: When capturing a moving image, a CPU 14 controls a CCD 2
Is switched to a thinning-out reading mode and an addition reading mode for driving. In the addition reading mode, since the signal charges of a plurality of pixels are added and used, sensitivity is increased, and high-quality imaging can be performed even in a dark imaging condition. In the thinning-out reading mode, generation of smear can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device such as a digital camera or a movie camera.

[0002]

2. Description of the Related Art Recently, in image pickup apparatuses such as so-called electronic still cameras and movie cameras, a still image / moving image pickup element is often used instead of a conventional moving image pickup element. Such a still image / moving image pickup device is a so-called multi-pixel image pickup device in which the number of pixels is set to be significantly larger than that of a conventional moving image-dedicated image pickup device for the purpose of capturing a still image with extremely high resolution. It is used.

Therefore, when a still image is picked up by such a multi-pixel image pickup device, compared with a conventional still image picked up by a moving image pickup device, it is very precise and of high quality, for example, A.
It is possible to obtain a high-quality image that can be fully appreciated even when printed in 4 sizes. On the other hand, if an attempt is made to shoot a moving image as it is with such a multi-pixel image pickup device, the number of pixels is too large, so the time required to read the image for one frame constituting the moving image becomes long, and a smooth moving image can be obtained. It gets harder. In this respect, a configuration is conceivable in which the operating speed of the image pickup device itself and the operating speed of the peripheral circuits of the image pickup device are increased to cope with this, but such an increase in speed causes a significant increase in cost and is not realistic.

Therefore, in the case of using a multi-pixel image pickup device, the pixel signals of all pixels are usually read individually when a still image is taken, but the signal of some pixels is thinned out and read when a moving image is taken. Has been done. Then, as a solid-state imaging device, a multi-pixel CCD (charge coupled device, charge
In the case of using a so-called CCD which is an imaging device, that is, a CCD image sensor, as a thinning method, a vertical method, that is, a method of thinning horizontal lines at a specific ratio is generally adopted at present. Has been done.

Further, such thinning-out reading is also used when the image sensor itself is used as a sensor for measuring a photographing condition, that is, for controlling a photographing system such as preliminary measurement of a photographing condition prior to photographing a still image or a moving image. It is also used in.

Here, in the CCD, photodiodes forming pixels are arranged in a two-dimensional lattice to form an image pickup surface, and an image formed by an optical system on the image pickup surface is converted into light for each pixel. This is an image pickup device of a type in which the magnitude of the amount of charge accumulated in each photodiode is extracted as a signal in accordance with the strength of. Then, the signal charge is CC for each pixel in order.
After being sent to the output circuit in D, the charge signal amount is converted into a voltage change signal by one charge-voltage converter, and then C
It is output to the outside of the CD. The operation of guiding the signal charge of each pixel to the output circuit in this manner is called transfer. A method that is generally performed as a method of sequentially transferring the signal charges of the pixels arranged in a two-dimensional rectangular shape to the output circuit is a method that combines so-called vertical transfer and horizontal transfer. Here, when the vertical direction of the imaging screen is vertical and the horizontal direction is horizontal, the vertical transfer is an operation of transferring the signal charges of all pixels all at once in the vertical direction and in the above-mentioned output circuit direction. The transfer means that the signal charge for one horizontal line, which was sent to the horizontal transfer path by the above-mentioned vertical transfer for one stage and was located at the end in the vertical direction, that is, the part closest to the output circuit, was transferred in the horizontal direction. This is an operation of simultaneously transferring to the output circuits of. At this time,
The signal charge for one pixel located at the end of the horizontal transfer path, that is, the portion closest to the output circuit is sent to the charge-voltage converter. In this way, by repeating horizontal transfer, all the signal charges in the horizontal transfer path are converted into charge-voltage, and when the output ends and the horizontal transfer path becomes empty, the vertical transfer is performed again. Then, after the signal charge for one horizontal line at the next end in the vertical direction is sent to the horizontal transfer path again,
Similarly, by horizontal transfer, they are sequentially sent to the output circuit and output. In this way, when all the pixels are output by sequentially repeating the simultaneous vertical transfer of the signal charges of all the pixels and the simultaneous horizontal transfer of the signal charges on the horizontal transfer path, the output of the pixel signals for one screen is completed. As a result, the electronic image can be formed and restored.

In the operation of transferring the signal charge of each pixel, normally, the vertical transfer is the positive transfer of transferring the signal charge in the horizontal transfer path direction, that is, in the positive direction as described above. In the vertical transfer, it is also possible to perform reverse transfer (vertical reverse transfer) in the opposite direction to the horizontal transfer path. However, in recent years, due to the tendency of pixels to become significantly finer and the power consumption to be reduced with the increase in the number of pixels, the transfer drive voltage has been lowered, and vertical transfer can be performed easily and efficiently as in the past. Has become difficult. Then, with such a point as the background, the CC of multiple pixels
In D, a design in which the efficiency of vertical transfer in the forward direction is pursued is made, and as a result, a CCD in which the transfer efficiency of reverse transfer is significantly reduced is also used.

Of the various types of CCDs, the one commonly used as the above-mentioned multi-pixel CCD is a CCD called an interline type, and this interline type CCD is further interlaced by a scanning type. Scan type CCD (hereinafter interlaced CC
D) and a progressive scan CCD (hereinafter referred to as progressive CCD). The interlaced CCD currently has the best balance between cost and performance, and is widely used and adopted as a structure suitable for a multi-pixel image pickup device. In this interlaced CCD, the number of horizontal lines of signal charges (also called pixel signal charges, charges, and pixel charges) that can be held in the vertical transfer path is half the number of horizontal lines of photodiodes that are photoelectric conversion units and constitute one pixel. Therefore, in order to read all the pixels independently, one frame is divided into two fields, and the even lines and the odd lines are alternately read, that is, interlaced and read twice. Therefore, as a charge read electrode (also called a signal charge read electrode or a charge read gate electrode) to the vertical transfer path of the signal charge on the photodiode, two systems for an even line and an odd line are prepared. Then, in the interlaced CCD, for example, by increasing the number of the charge reading electrodes from two to four, only some lines are selectively read out and all combinations of color filters are read out to the vertical transfer path in one field. It is possible to adopt a configuration in which the line reading has selectivity such that the rest is not read, and the line thinning function is easily realized. In addition, such a multi-pixel interlaced CCD
In general, the vertical transfer is performed by four-phase driving, and in order to realize the line thinning function, for example, the number of electrodes of the vertical transfer path is six, including the four systems of the charge read electrodes. Become.

On the other hand, in contrast to such an interlaced CCD, the progressive CCD can hold the signal charges in the vertical transfer paths by the number of lines of the photodiode, so that all the lines of one frame can be sequentially read from the beginning. it can. Therefore, if the thinning-out is not performed, the charge read-out electrode can be configured by one system, but in order to realize the read-out line selectivity in order to perform the thinning-out reading, one more system of the charge read-out electrode is added. . Therefore, in the vertical transfer of the progressive CCD, when a total of two systems of charge read electrodes are included, the number of electrodes of the vertical transfer path becomes five in the conventional four systems in the case of four-phase drive, and in the case of three-phase drive. Will change from the conventional 3 systems to 4 systems.

Further, although the multi-system of the charge reading electrode structure is disadvantageous as compared with the conventional structure, the internal wiring of the CCD is complicated and the external CCD driving circuit is increased by the increase of the electrode structure. It is used in most multi-pixel CCDs, as there may be no lower cost alternative.

Conventionally, as described above, the all-pixel individual reading mode in which the signal charges of all the pixels of the CCD are independently read and used, and only the signal charges of some of the pixels of the CCD are selectively read and others. 2. Description of the Related Art There is known an imaging device that switches between a thinning-out reading mode in which signal charges of pixels are not used and is discarded and is used. That is, as a still mode for still image shooting, an all-pixel individual read mode is used, and for thinning read mainly for moving image shooting or preliminary measurement before shooting, which requires high frame rate driving. Mode is used.

In addition to the above-described general line thinning-out reading, for example, various horizontal line thinning-out and line addition reading methods are available for progressive CCDs as shown in Japanese Patent Laid-Open No. 10-136244. Proposed. These methods are roughly classified into (1) a method of reading only n lines out of m lines (m>
n, m ≧ 3), (2) a method of adding and reading the signal charges of n lines out of m lines (m> n), (3) q continuous in the vertical direction
Three methods of adding pixel signals of lines and outputting the result are shown. Then, in contrast to a configuration in which unnecessary lines are simply thinned out, a configuration in which signal charges are added between a plurality of lines and a frame rate is improved is shown. Further, for example, as disclosed in Japanese Patent Laid-Open No. 10-210367, the signal charges of all the pixels of the CCD are independently read and used at the time of shooting a still image, and the pixels of the CCD are taken at the time of shooting a still image or a moving image. A configuration is known in which a part of the data is thinned out and read out, or added and read out.

That is, according to the conventional method of selectively reading out only a specific line and thinning out the rest, the frame rate can be improved, but the sensitivity is lowered. That is, when a moving image is shot in the thinning readout mode in a dark shooting situation, the sensitivity is insufficient and the S / N (signal-to-noise rati)
It becomes a bad image of o). Further, in the preliminary measurement such as photometry and distance measurement prior to the main photographing, the sensitivity is insufficient and the accuracy is remarkably lowered. And, in the case of compensating for such a lack of sensitivity at the time of preliminary measurement by projecting auxiliary light, the cost is large,
It is necessary to use a very bright lamp with a large outer shape and high power consumption. If the sensitivity is insufficient, the exposure time for the preliminary measurement cannot be shortened while keeping the measurement accuracy short.Therefore, the so-called time lag required from the user's intention of photographing to the start of exposure of the main photographing is large. May be.

Further, if lines are simply thinned out at the time of shooting a moving image, the spatial frequency reproducibility of the taken image may be deteriorated, moire may occur, and the quality of the image may be significantly impaired. That is, in the state where the lines are thinned out, the MTF (m
Since the odulation transfer function remains unchanged, significant aliasing distortion occurs. This phenomenon is called moiré, and is a phenomenon in which, for example, an object having a fine striped pattern appears in a thick striped pattern different from the actual image, which is not desirable for an image pickup apparatus.

To alleviate such a phenomenon, the line addition is not simply thinned out for the purpose of improving the frame rate, but line addition is incorporated as shown in Japanese Patent Laid-Open No. 10-136244. It has been known. Then, even if the MTF of the photographing lens is high on the spatial sampling frequency after line thinning, the aperture ratio increases when line addition is performed, and the spatial frequency components in the high frequency band are reduced, and the same effect as the spatial filtering process can be obtained. To be And
In order to maximize this effect, for example, instead of thinning out 4/5 lines out of all the lines and reading out 1/5 lines in order to increase the frame rate by 5, 5 lines have the same color of the color filter. By adding and reading out with each other, all pixels are eventually read out at a frame rate of 5 times, the effect of the spatial filter is maximum, and the signal charge of all pixels contributes to imaging, so that the aperture ratio is The same as when shooting a still image.

However, the above-mentioned Japanese Patent Laid-Open No. 10-136.
Japanese Patent Laid-Open No. 244 does not propose a method of reading out signal charges of all pixels by adding a plurality of lines of the same color as described above. Add the signal charges of consecutive lines on the vertical transfer path, or add on the horizontal transfer path,
Although a method of reading out all pixels is mentioned, in this method, a color C other than the vertical stripe filter array is used.
In the case of a CD, color mixing occurs, which not only causes a serious adverse effect on color reproducibility, but also has a problem that the original color cannot be reproduced depending on the combination of color mixing. Here, although not shown in the above-mentioned Japanese Laid-Open Patent Publication No. 10-136244, if it is attempted to realize all-pixel reading by adding a plurality of lines of the same color with the configuration described in this publication, for example, the above-mentioned 5-line addition is performed. In this case, assuming that the color filter array is a Bayer array as in this publication function, there are two types of color combinations in one column, and each color is read individually, and further, 5 pixels are read individually for each color. Since it is necessary, a total of 10 systems are required for the charge read electrodes, and in the case of vertical transfer drive, a total of 12 systems are required for the vertical transfer electrodes. The existing three-phase vertical transfer and thinning-out compatible three-phase multi-pixel progressive CCD vertical transfer electrodes have four systems as described above. Therefore, eight systems of external vertical transfer drive circuits are added. Therefore, the scale of the CCD drive circuit will be significantly increased. Furthermore, CCD
As the number of pixels increases and the number of addition lines increases, the number of vertical transfer electrode systems also increases correspondingly. Further, such an increase in the number of vertical transfer electrode systems is not preferable in terms of cost, downsizing of the apparatus, power consumption, and the like.

If the shooting condition is extremely bright,
For example, smear (smear) that appears as streaks where signal charges overflowing from each pixel leak into the vertical transfer path occurs, and in the addition read mode in which pixels are added and read compared to the normal thinning read mode, The image quality may be impaired.

For this reason, as shown in Japanese Patent Laid-Open No. 10-210367, the quality of an image may be impaired if it is limited to either thinning-out reading or addition reading when shooting a moving image.

[0019]

As described above, when a multi-pixel image pickup device is used for a moving image-dedicated image pickup device in order to improve the quality of a still image, the frame rate is improved. Although a configuration is adopted in which pixel signals are thinned out at the time of shooting, in this case, the image quality of a moving image is deteriorated by a method of simply selectively reading out only a specific line and thinning out the rest. On the other hand, when the signal charges of all the pixels are added and used in the conventional configuration, there is a problem that the configuration becomes complicated and the cost is increased. Also, depending on the pixel addition method, smear may impair the image quality.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image pickup apparatus which can realize high image quality and high function and can reduce the cost with a simple structure.

[0021]

According to another aspect of the present invention, there is provided an image pickup device comprising a plurality of pixels provided with photoelectric conversion means and arranged in a predetermined pattern, and a control means for controlling the image pickup element. An image processing unit to which the signal charge output from the image pickup device is input, and the control unit reads out the signal charge of some pixels of the image pickup device and outputs the signal charge to the image processing unit at the time of shooting a moving image. The thinning readout mode and the addition readout mode in which the signal charges of the pixels of the image sensor are read out and the signal charges of a plurality of pixels are added and then output to the image processing means can be switched.

In this structure, when the moving image is taken, the thinning-out reading mode and the addition reading mode are switched manually or automatically by the control of the control means according to the shooting situation and the object to be shot.
It is easy to improve the image quality. Further, since switching between the thinning readout mode and the addition readout mode can be performed by controlling the image pickup element, the configuration is not complicated and the manufacturing cost is reduced.

According to a second aspect of the present invention, there is provided an image pickup device according to the first aspect, wherein the image pickup element is a CCD solid-state image pickup element having a plurality of pixels in which a plurality of colors are arranged in a predetermined pattern. In the read mode, signal charges of a plurality of pixels of the same color are added together.

In this configuration, the CCD solid-state image pickup device which is generally used is used, the manufacturing cost is reduced, the quality of the image is improved, and the processing speed is improved.

According to a third aspect of the present invention, there is provided an image pickup device including a plurality of pixels provided with photoelectric conversion means and having a plurality of colors arranged in a predetermined pattern, control means for controlling the image pickup element, and the image pickup device. An image processing unit to which the signal charge output from the element is input, wherein the control unit reads out the signal charge of a part of the pixels of the image sensor during the preliminary photographing for measuring the data for the main photographing. A thinning-out reading mode for outputting to the processing means, an addition reading mode for reading out signal charges of pixels of the image sensor and adding signal charges of a plurality of pixels of the same color, and then outputting to the image processing means, and a pixel of the image sensor The signal charge is read out and the signal charges of a plurality of pixels of different colors are added, and then output to the image processing means.

In this configuration, during the preliminary shooting, the thinning-out reading mode, the addition reading mode, and the color-mixing addition reading mode are automatically switched by the control of the control means in accordance with the shooting situation and the shooting target. The data for actual shooting is effectively measured, and the quality of the image during actual shooting is improved.

An image pickup device according to a fourth aspect is the image pickup device according to any one of the first to third aspects, in which the control means switches between the addition read mode and the thinning read mode in accordance with the brightness of the photographing condition. Is to drive.

In this configuration, depending on the brightness of the shooting condition, when it is dark, the mode is switched to the addition reading mode, and an image of higher quality than the thinning reading mode is taken or high-speed processing becomes possible.

According to a fifth aspect of the present invention, in the image pickup apparatus according to any one of the first to fourth aspects, the control means determines the possibility of occurrence of moire, and when there is the possibility of occurrence of moire. The image pickup device is driven by switching to the addition read mode, and in the thinning read mode in other cases.

In this structure, the thinning-out reading mode is switched to the addition reading mode according to the object to be photographed, so that the generation of moire is suppressed and a high-quality image is photographed.

According to a sixth aspect of the present invention, in the image pickup apparatus according to any one of the first to fifth aspects, the control means determines the possibility of occurrence of smear, and when there is the possibility of occurrence of smear. The thinning readout mode is switched to the addition readout mode in other cases, and the image sensor is driven.

In this configuration, the addition reading mode is switched to the thinning reading mode according to the object to be photographed, so that the deterioration of the image quality due to smear is suppressed and a high quality image is photographed.

An image pickup device according to a seventh aspect is the image pickup device according to any one of the first to sixth aspects, in which the image pickup device is driven by the control means in the addition read mode,
It is provided with a saturation suppressing means for suppressing the saturation of the signal inside the image pickup device.

Further, in this configuration, since the saturation suppressing means is provided, it is possible to suppress the saturation of the signal inside the image pickup device in the addition reading mode, and the image quality is improved. Further, it is not necessary to use a dedicated image pickup device having a large capacity, and an increase in manufacturing cost is suppressed.

An image pickup device according to claim 8 is the image pickup device according to any one of claims 1 to 7, wherein the control means reads out the signal charges of some pixels of the image pickup element and outputs the signal charges to the image processing means. The mode, the addition read mode in which the signal charges of the pixels of the image sensor are read and the signal charges of the plurality of pixels are added, and then output to the image processing unit, and the signal charges of substantially all the pixels of the image sensor are independently set. The switching control is performed between the all-pixel individual reading mode used for reading and use.

In this structure, the all-pixels individual reading mode is used to capture a high-definition still image, for example, while the thinning-out reading mode or the addition reading mode is used to obtain a high-speed frame rate preliminary measurement. Alternatively, a moving image is taken.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an image pickup apparatus of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes an image pickup device. The image pickup device 1 is called a digital camera, a movie camera, or the like, and is a so-called still image / moving image device capable of shooting still images and moving images. It can be displayed.

The image pickup apparatus 1 includes a CCD 2 as an image pickup element, a CCD drive circuit 3 for driving the CCD 2, an analog processing circuit 4 constituting an image processing means to which the output of the CCD 2 is sequentially input, and an A / D conversion. 5, image processing circuit 6, memory 7, image display device 8 for displaying the contents of the memory 7, image recording medium for recording the contents of the memory 7.
(Recording device) 9, diaphragm 10 that constitutes an optical system, mechanical shutter
11, a lens 12, a CPU 14 constituting a control means, a casing (not shown), operation means such as a release button and a changeover switch, a power supply device, an input / output terminal, and the like.

The CPU 14 is a so-called microprocessor and controls the entire system. In the present embodiment, at least the F value control of the diaphragm 10, the opening / closing control of the mechanical shutter 11 and the focus control of the lens 12 are performed. Drive control of the CCD 2 via control of the CCD drive circuit 3, control of the analog processing circuit 4, control of the image processing circuit 6, memory 7
Processing of the data recorded in, the control of the image display device 8, the recording and reading of the image data to and from the image recording medium 9, and the like.

For example, when shooting a moving image, the CPU 14
Adjusts the amount of subject light incident on the CCD 2 by opening the mechanical shutter 11 and controlling the F value of the diaphragm 10.
Further, the electronic shutter of the CCD 2 is changed via the CCD drive circuit 3 to control the exposure amount.

The CCD 2 is a solid-state image pickup device, and is a CC using a charge coupled device (CCD).
As will be described later, the CCD 2 as a D image sensor has a pixel structure shown in FIG. 2, and is a so-called color Bayer array thinning-compatible color single plate, multi-pixel interline interlaced scan CCD, which is also used for still images and moving images. The feature is that the number of pixels is significantly larger than that of CCDs used exclusively for moving images. Therefore, while shooting a still image all pixels are read out individually by using a mechanical shutter, while when shooting a moving image, 1/5 of all horizontal lines. Only thinning out can be selectively read out, and even if there are many pixels, it is devised to maintain a high frame rate (number of frames per unit time) during moving images.

The CCD 2 is driven by the drive signal of the CCD drive circuit 3 and outputs the analog video signal resulting from the photoelectric conversion of the subject light to the analog processing circuit 4. Then, the analog processing circuit 4 comprises a correlated double sampling and gain control amplifier,
It removes noise from the analog video signal output from 2 and amplifies the video signal. Here, the CPU 14 is, for example,
The gain of the gain control amplifier of the analog processing circuit 4 is controlled.

The output of the analog processing circuit 4 is A
It is input to the / D converter 5 and converted into a digital signal here. Furthermore, the video signal converted into a digital signal is
It is temporarily recorded in the memory 7 as it is and waits for the subsequent processing, or is input to the image processing circuit 6. And
The video signal input to the image processing circuit 6 is subjected to image processing and then displayed by the image display device 8 via the memory 7, or in accordance with a user's operation, the image recording medium 9
While moving to, it is recorded as a still image. The unprocessed image data temporarily recorded in the memory 7 is processed by one or both of the CPU 14 and the image processing circuit 6.

Next, the outline of the structure and driving of the CCD 2 will be described.

As shown in FIG. 2, the CCD drive circuit 3 is C
The drive signal applied to CD2 includes vertical transfer path gate electrodes V1A, V1B, V2, V3A, V3B and V4 through which the vertical transfer path gate signal flows. Further, the CCD drive circuit 3 includes a CPU
A driving mode switching signal is input from 14, and the CCD driving circuit 3 switches the driving operation mode of the CCD 2 by this driving mode switching signal. That is, in the present embodiment, the thinning-out reading mode (first driving),
The addition read mode (second drive) and the all-pixel individual read mode (third drive) are switched.

The CCD 2 has a portion of pixels (R0, G5, R10, G15, ..., G0, B shown by hatching in FIG. 2).
5, G10, B15, ...) are arranged so that the vertical transfer path gate electrodes are selectively read out, and even in the case of a multi-pixel CCD, by performing thinning-out reading of pixels (lines), a high frame It is devised so that the rate can be realized.

That is, in the CCD 2 in the thinning-out reading mode, as shown in FIG. 14, the voltage application operation to the vertical transfer path electrodes is performed to read out the signal charges to the vertical transfer paths, and thereafter, three-stage vertical scanning is performed. By repeating transfer, horizontal transfer, two-stage vertical transfer, and horizontal transfer, it is possible to selectively read only 1/5 of all horizontal lines, that is, only 1/5 of all pixels. This thinning-out reading mode is characterized by a frame rate as high as 5 times that of reading all pixels individually, and is generally used for shooting and displaying moving images. Further, in the thinning-out reading mode, when the user of the image pickup apparatus 1 presses the release button during the shooting of a still image or the like, and during the main shooting, for example, the subject brightness measurement, the subject It is also used as a means to obtain preliminary measurement images for distance measurement at high speed.

In the CCD 2, the addition read mode can also be called the same-color addition all-pixel read mode. As shown in FIGS. 15 and 16, a voltage application operation is performed on the vertical transfer path electrodes to perform signal charge. To the vertical transfer path, and then 1-stage vertical transfer, horizontal transfer, 4
By repeating the step vertical transfer, horizontal transfer ... Or as shown in FIGS. 30 and 31, voltage application operation to the vertical transfer path electrode is performed to read out the signal charge to the vertical transfer path. By repeating the four-stage vertical transfer, the horizontal transfer, the one-stage vertical transfer, the horizontal transfer, and the like, the same colors are added by 5 pixels without mixing the color filter pixels,
It is possible to read out signal charges for all pixels at a frame rate that is five times as high as when reading all pixels individually. In the case of the driving method shown in FIGS. 15 and 16,
It is necessary to provide a line buffer in the image processing circuit 6 in the subsequent stage of the CCD 2 or use the memory 7 to switch the even and odd numbers of the input line order. Any of the configurations shown in FIG. 31 is finally equivalent to the sensitivity being five times as high as that in the thinning-out reading mode in which 1/5 of the pixels are selected, and 1 / An image signal having the same frame rate can be obtained in an output form substantially similar to the thinning-out reading mode in which 5 pixels are selected. Then, in the driving method in the addition read mode, vertical transfer is performed while the charge read pulse (31a in FIG. 15, 31a, 32a in FIG. 30) is being output, thereby performing addition of a plurality of pixels on the vertical transfer path. be able to. Therefore, this addition read mode also has a high frame rate as one of the features, similar to the thinning-out read mode.
It is ideal for display and preliminary measurement before actual shooting.

Further, in this CCD 2, the all-pixel individual reading mode is set to 2 as shown in FIGS. 12 and 13.
This is a mode in which the signal charges of all pixels on the CCD 2 are individually read out using a field, and one frame is divided into two with even lines and odd lines, and the operation of the physical light shielding means such as the mechanical shutter 11 is performed. In addition to this, since the frame rate is very slow, it is not suitable for moving images, but all the pixels of a so-called multi-pixel CCD are read independently, so it is an extremely high-definition image that is satisfactory as a still image. Can be obtained.

Next, the switching operation of these read modes will be described.

First, as the first embodiment, a configuration will be described in which the thinning readout mode and the addition readout mode are automatically switched by the image pickup apparatus 1 itself with the light amount of the subject as a determination condition to capture a moving image. To do.

First, the CPU 14 sets CC as an initial state.
Addition read mode of the CCD 2 via the D drive circuit 3
Operate with (second drive). This addition read mode is characterized by high sensitivity as compared with the thinning read mode, and is most suitable for indoor shooting, night shooting, and the like. For example,
In the shooting operation in the thinning readout mode, the gain of the analog processing circuit 4 must be increased, and even in a dark shooting condition in which the S / N is deteriorated and the image quality is remarkably deteriorated, it is five times as large as in the addition readout mode. If the sensitivity is high, a high S / N can be maintained with a low gain. Then, in this initial state, the video signal output from the CCD 2 passes through the analog processing circuit 4, the A / D converter 5, the image processing circuit 6, and the memory 7 and is substantially simultaneously displayed on the image display device 8.
It continues to be displayed (in real time). If the user intends to record a moving image by pressing down a release button (shooting button) (not shown), moving image data for the intended period is recorded on the image recording medium 9. Further, in the case of shooting a moving image, the pan of the image pickup apparatus 1 and the movement of the main subject,
Due to movements or changes in conditions other than the main subject on the screen, the light amount of the subject will continue to change.
In order to maintain the exposure amount of 2 always appropriate, as the exposure control, the aperture 10 or the electronic shutter of the CCD 2 and, in some cases, the gain of the analog processing circuit 4 is controlled by the CPU 14 in the present embodiment. I can continue. That is, the CPU 14 regularly monitors (monitors) the image data recorded and updated in the memory 7 one after another, and the CCD 14
The exposure amount status of 2 is constantly monitored. When it is determined that the exposure amount is small, that is, the screen is dark, the CPU
In the case of 14, the diaphragm 10 has a smaller F value, that is, the CCD 2
The amount of light incident on is controlled to increase. On the contrary, if you judge that the exposure is high, that is, the screen is bright,
The CPU 14 increases the F value of the diaphragm 10, that is, C
The control is performed so that the amount of light incident on CD2 decreases. However, no matter what diaphragm mechanism, the F value cannot be changed indefinitely, and in a brighter condition than a predetermined brightness, the CCD 2 can be changed only by changing the F value of the diaphragm 10.
In addition, it becomes impossible to control within the proper exposure amount range. In such a case, the CPU 14 controls the CCD drive circuit 3 and
The electronic shutter operation of U14 is made effective, and the amount of this electronic shutter is controlled so that the excessive exposure amount that could not be controlled by the diaphragm 10 becomes a proper amount.

However, in the case of the interline CCD, when the exposure amount is controlled by the electronic shutter, there is a problem that the signal-to-smear ratio deteriorates. That is, the accumulation time of the image signal charge is shortened by the electronic shutter, but the amount of smear generated in the vertical transfer path is always constant regardless of the operation of the electronic shutter. The smear ratio gets worse. That is, as the electronic shutter is operated and the shutter speed is increased, the influence of smear appearing on the screen becomes worse. In addition, in the normal thinning-out reading mode in the present embodiment, vertical transfer is performed on the vertical transfer path in which smear is accumulated by repeating three steps and two steps, whereas in the addition reading mode, four steps, one step. Since the vertical transfer is performed by repeating one stage or one stage and four stages, the smear difference between the even line and the odd line adjacent to each other becomes large, and depending on the image processing method after the vertical transfer, The smear that occurs causes a horizontal stripe-shaped luminance difference, which may impair the quality of the image.

Therefore, in the present embodiment, the CPU 14
When the exposure speed of the CCD 2 is judged and the shutter speed of the electronic shutter of the CCD 2 which is instructing the CCD driving circuit 3 becomes higher than a certain value, in other words, the number of electronic shutter pulses output from the CCD driving circuit 3 is more than a certain number. When such a situation occurs, the CCD drive circuit 3 is instructed to switch the driving of the CCD 2 from the addition read mode to the thinning read mode. Further, in the present embodiment, by utilizing the thinning-out reading mode, it is possible to suppress deterioration of image quality due to smear to a low level regardless of the image processing method.

As described above, according to the image pickup apparatus 1 of the present embodiment, the high image rate and the high function can be realized by providing the high frame rate driving for the multi-pixel CCD 2 in the two modes and appropriately switching them. That is, in addition to the thinning readout mode, an addition readout mode (same-color addition all-pixel readout mode) is adopted, and by appropriately switching and using them, the advantages of both are utilized, the disadvantages are compensated, and the performance of the image pickup apparatus 1 as a whole is improved. Can be improved.

That is, according to this embodiment, the CCD
Regarding the driving method of No. 2, when shooting a moving image, depending on the brightness of the shooting condition, if the shooting condition is dark, the addition reading mode is switched, and if it is bright, the thinning reading mode is switched to the conventional thinning reading mode. When the brightness is bright, it is possible to obtain at least the current image quality in which deterioration of the image quality due to smear is suppressed.

Further, the CCD 2 is not a special CCD 2 but a CCD, which is commonly used in electronic still cameras and the like, which corresponds to thinning and is also used as a still image / moving image.
Since the (color interline type interlaced CCD) 2 can be used as it is, and the image quality can be improved by switching the driving method of the CCD 2, the manufacturing cost can be suppressed.

Further, as described above, in addition to the configuration in which the image pickup apparatus 1 itself automatically switches between the thinning-out reading mode and the addition reading mode, the user can watch a moving image displayed on the image display device 8 or the like. When an unacceptable smear is recognized, the addition read mode can be switched to the thinning read mode by operating a changeover switch (not shown), that is, manually.

Further, in the thinning-out reading mode, the CCD 2
, The shooting situation becomes dark, and the sensitivity is insufficient in the thinning readout mode, the gain of the analog processing circuit 4 increases, and as a result, the S / N decreases and the image display device Even in the case where noise on the screen displayed on the screen 8 or the like becomes unacceptable, the thinning-out reading mode can be switched to the addition reading mode by a manual operation.

In addition read mode (same color addition all pixel read mode), as will be described later in detail, vertical transfer is performed on the vertical transfer path by performing vertical transfer while applying the charge read voltage to a specific charge read electrode. This is a CCD image pickup device driving method in which the signal charges of pixels of the same color are added and the signal charges of pixels that are discarded in the thinning-out reading mode are also added and used to eventually read all pixels. According to this driving method, since the image signal can be obtained in the addition read mode in the same frame rate and in substantially the same output form as in the thinning read mode, it is possible to switch between each other very easily.

Next, the operation of the above-described first embodiment will be described with reference to the flowchart shown in FIG. In this flowchart, moving image data sequentially output from the CCD 2 shown in FIG. 1 is displayed on the image display device 8 when the image pickup apparatus 1 is in a standby state for shooting and recording moving images, or as an electronic viewfinder operation during still image shooting. It is supposed to be displayed at the same time (real time). Furthermore, from this state, movie recording sequence, still image shooting and recording
It is premised that the sequence is changed to the (main photographing) sequence or the state in which the user manually fixes the driving operation to the thinning readout mode or the addition readout mode by various switch (SW) inputs. Therefore, first, in step 100, the initial state of each switch (SW) is confirmed, and thereafter, the setting is made to permit the interrupt permission from each switch (SW). For example, after this time point, when the operation of pressing down the release button is detected by interruption, the routine immediately shifts to the still image shooting routine. Also, for example, CC
When the switch (SW) that fixes D2 to the addition read mode is turned on, it is detected by an interrupt that the transition to the thinning read mode is not started after that point.

If the switch (SW) is not detected in step 100, the mechanical shutter 11 is opened (step 101), the addition read mode is set (step 102), and the photographing operation of the CCD 2 is started. Then, the amplifier gain of the analog processing circuit 4 is set to the lowest value in the assumed range (step 103). Then, the feed bag exposure control is started by controlling the F value of the diaphragm 10 (step
104-106). Then, after this exposure control, if the F value is equal to or greater than the value assumed in advance (step 105) and it is detected that the F value has become the maximum (step 106), further exposure control is not performed for the F value. Since this is not possible, the process shifts to exposure time control by the electronic shutter (steps 107 to 109).
However, when it is detected that the exposure time of the electronic shutter is a certain value or less, that is, the number of electronic shutter pulses is the specified value or more, and the risk of smearing is recognized (step 108), the thinning reading is performed from the addition reading mode. The driving of the CCD 2 is switched to the mode (step 110),
The electronic shutter pulse is controlled to be smaller.

Further, when it is detected that the number of electronic shutter pulses has reached the minimum value in the state where the thinning readout mode (first drive) is switched to (step 109),
Exposure control is performed to control the F value of the aperture 10 (step 10
4 to 106), and when it is detected that the F value is the minimum or less than or equal to the value assumed in advance (step 105), that is, when it is recognized that the shooting condition is sufficiently dark, the addition reading mode is set again.

If the light quantity is still insufficient even in the addition read mode (step 111), the gain of the analog processing circuit 4 is manipulated to compensate for the light quantity shortage (steps 113 to 114). Further, when it is detected that the gain setting of the analog processing circuit 4 has become the lowest value in the assumed range (step 114), that is, if there is a light amount above a certain level, the F value of the diaphragm 10 is controlled again. To return to the exposure control of the feed bag (steps 104 to 106).

In this way, the driving of the CCD 2 is automatically switched between the thinning readout mode and the addition readout mode in both directions, and the user switches
It is also possible to manually select and fix one of them by operating (SW).

Although the first embodiment has been described with respect to the shooting of a moving image, the operation of this embodiment can be applied to the shooting of a still image, for example, when the resolution is low.

That is, according to the present embodiment, in the image pickup apparatus using the color interline type CCD image pickup device capable of thinning, when shooting a moving image or a low resolution still image under a very dark shooting condition. It is possible to obtain a high-sensitivity and high S / N image that cannot be realized by the conventional method. Furthermore, under bright shooting conditions where smearing may occur, it is possible to switch to a conventional method in which image quality deterioration due to smear is relatively small, and under all shooting conditions, high image quality can be achieved overall.

Next, a second embodiment will be described.

The configuration of this embodiment is the same as that of the first embodiment shown in FIG.
The embodiment is the same as that of the first embodiment, that is, the signal flow, the function and operation of each unit, and the like are the same as those of the first embodiment. Here, an embodiment will be described in which the thinning-out reading mode and the addition reading mode are switched to each other as preliminary measurement (preliminary shooting) before actual shooting of still image shooting or moving image shooting.

At present, for example, in a digital still camera or the like, in order to reduce the manufacturing cost, a CCD for main photographing is used for both distance measurement and photometry. The operation of this preliminary measurement will be outlined with reference to the time chart of FIG.

First, when the user presses the release button, the mechanical shutter opens and the CCD 2 is exposed. Preliminary measurement starts from here, but in this example, the image capturing for photometry is performed once, the image capturing for white balance measurement is performed once, and the image capturing for distance measurement is performed twice. And
In this example, the CCD 2 shown in FIG. 1 is normally driven in the thinning readout mode during this preliminary measurement period. In FIG. 4, the photometric image A1 is the one exposed with A, CC
It is output from D2. Similarly, the white balance image B1 is exposed with B, and the distance measuring images C1 and D1 are exposed with C and D, and are output from the CCD 2. The number of times of photographing in each preliminary measurement is not necessarily limited to the number shown here.

After that, the CPU 14 responds to the exposure condition obtained from the result of the preliminary measurement, that is, the focus position of the lens 12 of FIG. 1, the F value of the diaphragm 10 and the mechanical shutter 11 of FIG.
By optimally controlling the combination of the shutter speeds, the exposure for the main photographing is performed at the timing E in FIG.

Incidentally, as in the first embodiment, the CCD
When 2 is an interlaced scan CCD, in the image output at the time of still image shooting, as shown in FIG. 4, even lines and odd lines are output over the vertical synchronizing signal period for two screens.

Here, when the shooting condition is very dark,
Even if the exposure is performed for one vertical synchronization signal period at the time of each preliminary measurement, the light quantity is still insufficient and the gain of the analog processing circuit 4 shown in FIG. 1 must be increased. However, if the gain is increased, the S / N of the image signal is deteriorated, which may cause a problem in the determination of the preliminary measurement. Therefore, in this way, the CPU 14 shown in FIG.
As a result of the photometric operation of A and A1, when it is determined that the shooting condition is darker than the predetermined level, the CPU 14 causes B, B1 and
In the white balance and distance measuring operations after C, C1, D and D1, the driving of the CCD 2 is switched to the addition read mode. In this case, if the photometric operation is performed again after switching to the addition reading mode, the photometric accuracy is further improved. Thus, in the addition read mode, the CCD
The sensitivity of No. 2 is substantially improved, for example, 5 times in this embodiment, so that extremely accurate preliminary measurement is performed even in a very dark imaging condition where accurate preliminary measurement cannot be performed in the thinning readout mode. be able to.

Next, the operation of the above second embodiment will be described with reference to the flow chart shown in FIG. This flowchart shows that the image pickup apparatus 1 is in a shooting standby state, or
In the state described in the first embodiment, it is assumed that the subroutine is a case where depression of the release button is detected by interruption.

First, when the mechanical shutter 11 is not open, the mechanical shutter 11 is opened (step 200), and the CCD 2
Is set to the thinning readout mode (first drive) (step 201). Next, after setting the exposure conditions for photometry (step 202), photometry processing is performed (step 203). If it is determined that the shooting condition is darker than the specified value and it is difficult to maintain the accuracy of the preliminary measurement thereafter (step 204), C
The drive of the CD2 is set to the addition read mode (second drive) (step 205), and the exposure condition for the white balance measurement reflecting the photometric result is set (step 206). On the other hand, as a result of the photometric processing, if the shooting condition is sufficiently brighter than the specified value, the thinning-out reading mode is maintained (step 204). Next, white balance processing (AWB) is performed (step 207), exposure conditions for distance measurement that reflect the result of photometry and the measurement result of white balance are set (step 208), and distance measurement processing is performed in this state (step). 20
9). Then, the exposure conditions for the main photographing that reflect the results of the photometry, the white balance, and the distance measurement are set (step 210), and the main photographing is performed (step 211).

As described above, according to this embodiment, during the preliminary measurement, by switching between the thinning-out reading mode and the addition reading mode depending on the brightness of the photographing condition,
In the conventional method, even when shooting for preliminary measurement prior to actual shooting of moving images or still images under extremely dark shooting conditions where measurement accuracy is degraded due to poor image quality due to insufficient sensitivity , Images with high sensitivity and high S / N are obtained,
High measurement accuracy can be maintained.

Further, under such a very dark photographing condition, auxiliary light is projected from a light source such as a lamp attached to the image pickup apparatus 1 to the subject at the time of preliminary measurement to compensate for the insufficient light quantity of the preliminary measurement image. In the above, by combining the addition read mode at the time of the preliminary measurement of the present embodiment, the brighter and more accurate preliminary measurement can be performed, while the sensitivity of the CCD 2 is improved, so that the light amount of the auxiliary light lamp is small. Since the same effects as in the past can be obtained, it is possible to use a lamp that is inexpensive, small, and low in power consumption, and can reduce the manufacturing cost.

That is, when the auxiliary light is mounted on the image pickup device as a measure against darkness and the auxiliary light is projected onto the subject at the time of preliminary measurement to compensate for the insufficient light amount, the relative sensitivity of the CCD 2 is dramatically increased by the addition read mode. Therefore, it becomes possible to use a lamp of low cost, small size, and low power consumption. Therefore, an image pickup apparatus having the same performance as the conventional one can be realized at low cost, with small size and low power consumption.

Next, a third embodiment will be described.

The configuration of this embodiment is the same as that of the first embodiment shown in FIG.
The embodiment is the same as that of the first embodiment, that is, the signal flow, the function and operation of each unit, etc. are the same as those of the first embodiment. Here, a method of shortening the time required for the preliminary measurement by using the addition read mode in the preliminary measurement (preliminary photographing) before the main photographing such as still image photographing or moving image photographing will be described.

As shown in FIG. 4, the preliminary measurement operation exists between the time the user depresses the release button and the time when the exposure for the main photographing is started. That is,
There is a time lag (time lag) between the moment the user intended to shoot and the time when the actual shooting operation was started and the exposure was started.
Exists. If this time difference is too large, a so-called photo opportunity is missed. Therefore, the shorter the time difference, the better, and the ideal is zero. In this respect, it is difficult to reduce the time of the preliminary measurement to zero in the configuration in which the image sensor and the distance measuring and photometric sensor are shared, but according to the present embodiment, the time difference can be made smaller than that in the conventional configuration. In addition, it is possible to maintain the same preliminary measurement accuracy as the conventional one.

The operation at the time of photographing a still image in this embodiment will be described with reference to the time chart of FIG.

During the preliminary measurement operation period, the CCD 2 is operating in the addition read mode (second drive). This FIG. 6 basically corresponds to FIG. 4 and includes A to D and A1 to D1.
4 has the same meaning as in FIG. 4, the photometric image A1 is exposed with A, the white balance image B1 is exposed with B, and the distance measuring images C1 and D1 are exposed with C and D. However, the time required for the preliminary measurement operation is cut in half. This is because the vertical synchronization signal period during the preliminary measurement operation is set to be reduced to half.
As described above, as a method of halving the vertical synchronization signal period, that is, one screen period during the preliminary measurement operation, for example, the basic clock of the CCD drive circuit 3 shown in FIG. Although a relatively simple method of halving the time (pixel rate) required for one pixel of the image signal output from the CCD 2 is conceivable, there is also a method described below.

Note that FIG. 6 also shows the state of vertical transfer, which will be described later. First, when the reading and addition of the signal charges to the vertical transfer path of the CCD 2 are completed by the charge reading operation in the addition reading mode (second driving), the vertical transfer is performed at high speed until an arbitrary position in the vertical direction of the screen is reached.
(F1 in FIG. 6). At this time, the signal output to the outside of the CCD 2 is invalid. Next, by vertical transfer in the addition read mode, an arbitrary number of lines are read (F2 in FIG. 6). The image signal at this time is valid. Then, when the image signals for the required number of lines are secured, the pixel signals remaining in the vertical transfer path are swept out again by high-speed vertical transfer (F in FIG. 6).
3).

By doing so, it is possible to read out an arbitrary position of one screen with an arbitrary width, that is, the number of lines. In photometry, white balance measurement, and distance measurement, the entire screen is not necessarily required, but the central portion is sufficient. Therefore, by the above method, for example, the central part of the entire screen is ⅓
By performing the operation of reading with the width of (line), the vertical synchronization signal period can be easily halved only during the preliminary measurement operation. Note that, in this way, a method of selectively acquiring images in continuous arbitrary sections by combining high-speed vertical transfer (hereinafter,
(Referred to as high-speed central reading) is known, but
The third embodiment is an application of high-speed central reading in the addition reading mode.

In any case, in the conventional configuration, if the operation time of the preliminary measurement is shortened, the exposure time becomes short, and it becomes impossible to obtain a sufficient signal amount even in the condition of photographing which is not so dark. In the mode, since the CCD 2 is operated in the addition reading mode, the operation time of the preliminary measurement is halved, and the sensitivity is 5 even if the exposure time for photometry, white balance measurement, and distance measurement is halved. Since the number of times is doubled, it is possible to secure a light amount with a surplus more than in the case where the time is not shortened in the thinning-out reading mode, that is, compared with the situation of the conventional time-consuming preliminary measurement.

In the third embodiment, basically, the addition read mode is used, but if the shooting condition is sufficiently bright, the thinning read mode can be selectively used. And this change is
The CPU 14 can automatically switch the image data based on the determination, or the user can manually switch the image data. Further, as to the method of shortening the time required for the preliminary measurement by using the addition read mode in the preliminary measurement, the second embodiment that switches between the thinning-out reading mode and the addition reading mode depending on the brightness of the photographing condition during the preliminary measurement is performed. In this case, further accurate and high-speed preliminary measurement can be realized by applying the central part high-speed reading while appropriately switching the drive mode in the preliminary measurement.

Next, the operation of the above third embodiment will be described with reference to the flowchart shown in FIG. This flowchart shows that the image pickup apparatus 1 is in a shooting standby state, or
In the state described in the first embodiment, it is assumed that the subroutine is a case where depression of the release button is detected by interruption.

First, when the mechanical shutter 11 is not open, the mechanical shutter 11 is opened (step 300), and the CCD 2
Drive is set to additive read mode (step 30
1). Next, the line reading of the CCD 2 is performed as high-speed reading of the central portion, and in this case, for example, in order to read 1/3 line of the screen at high speed, the CCD 2 is operated in combination with the addition reading mode and the vertical synchronizing signal period is set to the normal reading. 1/2
(Step 302). After setting the exposure conditions for photometry (step 303), as in the second embodiment,
Photometric processing is performed (step 304). Then, the exposure condition for the white balance measurement that reflects the photometric result is set (step 305), and then the white balance processing (AW
B) is performed (step 306), the exposure condition for distance measurement that reflects the result of photometry and the measurement result of white balance is set (step 307), and the distance measurement process is performed in this state (step 3).
08). Then, the exposure conditions for the main photographing that reflect the results of the photometry, the white balance, and the distance measurement are set (step 309), and the main photographing is performed (step 310).

As described above, according to the present embodiment, it is possible to significantly reduce the time required for the preliminary measurement by taking advantage of the high sensitivity as the addition read mode at the time of the preliminary measurement, and, for example, the exposure time for the preliminary measurement. The shutter response can be greatly improved by reducing the value to, for example, half. In other words, in the conventional method, in order to shorten the time for preliminary measurement, if the exposure time during image capturing for preliminary measurement is shortened by reading out a part of the screen at high speed, etc. As described above, insufficiency of sensitivity becomes a serious problem even under normal shooting conditions, but in the present embodiment, the accuracy of measurement is impaired by using the relatively high imaging sensitivity by the addition read mode. Therefore, the time required for preliminary measurement can be greatly reduced.

Next, a fourth embodiment will be described.

The configuration of this embodiment is the same as that of the first embodiment shown in FIG.
The embodiment is the same as that of the first embodiment, that is, the signal flow, the function and operation of each unit, etc. are the same as those of the first embodiment. Here, in the preliminary measurement (preliminary photographing) before the main photographing such as the still image photographing or the moving image photographing, three or more kinds of reading modes, here, thinning, addition, and color mixture addition are performed.
A method of switching the seed read mode and performing highly accurate preliminary measurement at high speed will be described.

The operation at the time of photographing a still image in this embodiment is the same as that shown in the time chart of FIG.

Here, in the mixed color addition read mode, the addition that intentionally causes a mixed color is performed. That is, the above-mentioned addition read mode is for avoiding color mixture and adding the signal charges of pixels of the same color, but the color mixture addition read mode intentionally mixes and reads the signal charges of pixels of different colors to obtain a luminance signal. A signal closer to is output for use in distance measurement, that is, autofocus, and is used only in preliminary measurement.

Then, in this mixed color addition read mode,
For example, in the CCD of the primary color Bayer array, all the signal charges of the R (red) pixels on the even line are read to the vertical transfer path (vertical register), and then the R signal charges are 1 /
In the state where two-stage vertical transfer is performed, the signal charge of the G (green) pixel on the odd line is read out onto the vertical transfer path to mix the R signal charge and the G signal charge, and further perform the vertical transfer. It is realized by a method of adding an arbitrary number of lines on a horizontal transfer path (horizontal register), and as described later in detail, it is realized by a method of performing vertical transfer while applying a charge read pulse. That is, these methods can generate a signal charge mixed with R + G and a signal charge mixed with G + B, and can realize a high frame rate.

Next, the operation of the above-described fourth embodiment will be described with reference to the flowchart shown in FIG. This flowchart shows that the image pickup apparatus 1 is in a shooting standby state, or
In the state described in the first embodiment, it is assumed that the subroutine is a case where depression of the release button is detected by interruption.

First, when the mechanical shutter 11 is not open, the mechanical shutter 11 is opened (step 400), and the CCD 2
Is set to the thinning-out reading mode (first driving) (step 401). Next, after setting the exposure conditions for photometry (step 402), photometric processing is performed (step 403). Here, if it is determined that the shooting condition (subject) is darker than the specified value and it is difficult to maintain the accuracy of the preliminary measurement thereafter (step 40
4) The driving of the CCD 2 is set to the addition reading mode (second driving) (step 405), and the exposure condition for white balance measurement reflecting the photometric result is set (step 40).
6). On the other hand, as a result of the photometric processing, when the shooting condition is sufficiently brighter than the specified value, the thinning-out reading mode is kept (step 404). Next, white balance processing (A
WB) is performed (step 407). Then, in the white balance processing, if the color of the subject is significantly biased, that is, if the white balance shift amount is determined to be larger than the predetermined value (step 408), the CCD 2
Is set to the mixed color addition read mode (fourth drive) (step 409), and the exposure condition for distance measurement that reflects the photometry result and the white balance measurement result is set (step 410). Performs distance measurement processing (step 41)
1). If the white balance deviation amount is less than or equal to the default value (step 408), the conventional reading mode is maintained, exposure conditions for distance measurement are set (step 410), and distance measurement processing is performed (step 411). . For example, when the subject is sufficiently bright and there is no color deviation, the driving of the CCD 2 is maintained in the thinning readout mode from the beginning. Then, the exposure conditions for the main photographing that reflect the results of the photometry, the white balance, and the distance measurement are set (step 412), and the main photographing is performed (step 413).

In this embodiment, when the color deviation of the object is recognized, the mixed color addition read mode is used, so that the distance measurement calculation can be executed easily and accurately, and the distance measurement can be performed. Can be accurate. That is, the color C
With CD2, when a subject with a marked color deviation is photographed, the level difference for each pixel (for each color) becomes very large in the thinning readout mode or the additive readout mode without color mixture, which is not suitable for distance measurement calculation. May be.
In this case, by intentionally performing the color mixture addition, the level difference for each pixel can be suppressed and the distance measurement can be accurately performed.

Note that distance measurement using color mixture addition is disclosed in, for example, Japanese Patent Laid-Open No. 10-136244, but unlike the configuration described in this publication, in the present embodiment, the same CCD 2 is used. It is possible to switch between addition of the same color and addition of mixed colors. And Japanese Patent Laid-Open No. 10-1
In the configuration described in Japanese Patent No. 36244, the white balance is
Although the preliminary measurement of (AWB) is performed at the time of color mixing addition, there is a problem that the color separation property is lost in the color mixing state, the color temperature cannot be measured accurately, and the accuracy of white balance setting decreases. ing. In this respect, according to the present embodiment, the preliminary measurement of the white balance is performed by selecting either the thinning-out reading mode or the addition reading mode in which no color mixing occurs, so that the color separability can be maintained. ,
Even in dark shooting conditions, since the additive reading mode that can improve the sensitivity can be used, the white balance can be set extremely accurately and the image quality can be improved.

In the fourth embodiment, too,
Similarly to the third embodiment, the preliminary measurement can be speeded up by extracting and using a specific portion on the screen. By thus combining the third embodiment and the fourth embodiment, more accurate preliminary measurement can be performed at high speed.

As described above, at the time of preliminary photographing, the optimum combination of only one mode, two modes, or three modes is automatically selected from the thinning readout mode, the same color addition readout mode, and the mixed color addition readout mode. By making a selection, effective data can be secured as preliminary measurement data, and the quality of images in actual shooting of moving images or still images can be improved.

Next, a fifth embodiment will be described.

The structure of this embodiment is the same as that of the first embodiment shown in FIG.
The embodiment is the same as that of the first embodiment, that is, the signal flow, the function and operation of each unit, and the like are the same as those of the first embodiment. Here, a method of suppressing moire by using the addition read mode (second drive) at the time of actual shooting of still image shooting or moving image shooting will be described.

In the present embodiment, the CCD is used when shooting a moving image.
2 is driven in the thinning read mode as an initial state.
In this thinning-out reading mode, pixels, that is, lines are simply thinned out, so that the spatial frequency reproducibility in the vertical direction of the screen is significantly deteriorated. For example, when there is a very fine horizontal stripe object, fine stripes are photographed like thick stripes, and false colors that do not originally exist can be seen at the boundary portion where black and white are sharp. This is a phenomenon called moire, which significantly impairs the quality of the captured image.

Therefore, in the present embodiment, the CPU 14
The moving images that are recorded and updated one after another in the memory 7 are monitored. Simultaneously with this monitoring, the spatial frequency distribution of the color difference components in the vertical direction of the screen is analyzed. Various methods such as a fast Fourier transform (FFT) can be used for this analysis.
Further, this analysis does not necessarily have to be performed on the entire screen, but may be performed on a specific part of the screen or may be performed on the entire screen discretely. If a relatively high frequency component distribution of the color difference components is recognized as a certain amount or more, it is determined that there is a risk of moire, and the CCD is determined.
The driving of No. 2 is switched from the thinning readout mode to the addition readout mode. In addition, in the addition read mode, a plurality of pixels that are spatially separated are added with the same color, so that an effect equivalent to that obtained through a low-pass filter can be obtained, and moire can be suppressed very effectively.

When the user monitors the moving image displayed on the image display device 8 of the image pickup device 1 and finds that an unacceptable moire is generated, the CCD 2 is manually driven to perform the addition reading from the thinning-out reading mode. You can also switch to mode.

Next, the operation of the above fifth embodiment will be described with reference to the flowchart shown in FIG. In this flowchart, the image display device 8 displays the moving images sequentially output from the CCD 2 when the image pickup device 1 is in a standby state for capturing a moving image or when a still image is captured as an electronic viewfinder operation.
It is supposed to be displayed simultaneously (real-time). At the same time, various switches (SW) are used to switch from this state to a movie recording sequence, a still image shooting / recording sequence, or a state in which the user manually fixes the drive operation from thinning readout mode to addition readout mode. ) It is assumed that the state is changed by input. Therefore, first check the initial state of each switch (SW), then
Settings are made to enable interrupts from each switch (SW) (step 500). For example, after step 500, when the depression of the release button is detected by an interrupt, the routine immediately shifts to the still image shooting routine. Also, for example,
When the switch (SW) for fixing the driving of the CCD 2 to the addition read mode is turned on is detected by an interrupt, the thinning read mode is not transitioned after this detection. If no switch (SW) input is detected in step 500, the mechanical shutter 11 is opened (step 50
1) Set the thinning readout mode (step 50
2) The photographing operation of the CCD 2 is started, and the process proceeds to the exposure amount automatic adjustment process (step 503). In this exposure amount automatic adjustment processing, the F value of the diaphragm 10, the electronic shutter of the CCD 2 by the CCD driving circuit 3, the gain of the analog processing circuit 4 and the like are sequentially switched, and the image is always displayed on the image display device with appropriate brightness. Controlled to be displayed. Then
Every time the automatic exposure amount adjustment processing is performed or once every plural times, the process proceeds to the moire occurrence determination processing (step 50).
Four). Here, the moiré occurrence status of the screen is evaluated, and if there is no danger of moiré occurrence, the driving of the CCD 2 is set to the thinning-out reading mode (step 506), and if the danger of moiré occurrence is detected, the CCD2 is detected. Is set to the addition read mode (step 505). After that, the process returns to step 503 again to perform the automatic exposure adjustment processing. It should be noted that in this step 504, it is determined whether or not moire has occurred in each of the thinning readout mode and the addition readout mode. However, for the same subject, the image in the addition readout mode is better than the image in the thinning readout mode. , The moire detection level becomes low. Therefore, the determination level is set in consideration of the characteristics of the acquired screen by each driving method.

As described above, according to the present embodiment, when the moire is likely to occur, the addition read mode is used, and in other cases, the thinning read mode is used, whereby the conventional line thinning is performed. It is possible to effectively suppress the occurrence of moire caused by the above, and it is also possible to manually switch the presence or absence of the suppression to reflect the intention of the operator.

Next, a sixth embodiment will be described.

When taking continuous pictures of a fast-moving subject by, for example, high-speed continuous shooting using the conventional thinning-out reading mode in a relatively dark shooting condition, the high-speed shutter can be released due to lack of sensitivity. Instead, the image may be blurred, but under such shooting conditions,
By using the addition read mode, it is possible to combine high-speed shutters, and it is possible to obtain clear continuous photographs without subject blurring.

Next, a seventh embodiment will be described.

As shown in FIG. 10, the configuration of this embodiment is similar to that of the first embodiment shown in FIG.
Substrate bias voltage switching circuit 13 as saturation suppressing means controlled by U14 to switch the substrate bias voltage of CCD 2
It is possible to easily remove so-called blooming. The parts other than the substrate bias voltage switching circuit 13 are the same as those in the first embodiment shown in FIG. 1, that is, the signal flow, the functions and operations of the respective parts are the same as those in the first embodiment. is there.

That is, when the driving of the CCD 2 is set to the addition read mode, that is, when a plurality of signal charges (pixel charges) are mixed and read in the CCD, the charge transfer capacity of the vertical transfer path or the horizontal transfer path poses a problem. It is possible that For example, when the signal charges for 5 pixels are added, the transfer capacity of each transfer path is required to be 5 times the saturated accumulated charge amount of the photodiode 15 as the photoelectric conversion means.
When the signal charge overflows on the vertical and horizontal transfer paths,
The signal charge of each pixel of the solid-state image sensor overflows and leaks to an adjacent pixel, which may cause so-called blooming in which an image of a highlight portion spreads.

As a countermeasure for this, it is conceivable to use a CCD manufactured by designing and manufacturing the charge transfer capacity of the vertical transfer path and the horizontal transfer path as a capacity commensurate with the amount of pixel mixture, but a dedicated CCD is used. This increases the manufacturing cost.

Therefore, when the CCD 2 of the normal design is used and the pixels are mixed in the addition read mode of the same color or the mixed color addition read mode, and the condition of the brightness of the object is not less than a certain level by the CPU 14. If it is determined that there is a risk of blooming, the CPU 14 controls the substrate bias voltage switching circuit 13 to switch the substrate bias voltage of the CCD 2 to a voltage higher than usual, and the saturated accumulated charge amount of the photodiode. By limiting the above, it is possible to suppress the blooming that occurs in the horizontal transfer path and the vertical transfer path while suppressing an increase in the manufacturing cost and improve the image quality.

Next, the operation of the seventh embodiment will be described with reference to the flowchart shown in FIG. This flowchart is the same as the flowcharts shown in the above-described first to sixth embodiments, in the step of switching to the addition read mode or the mixed color addition read mode, or in the step after this step, the situation immediately before or after the subject. It is supposed to be a subroutine when the brightness situation becomes clear.

First, the brightness of the subject is determined (step 600), and if it is determined that the subject is brighter than the specified value and there is a risk of blooming, the CPU 14 causes the substrate bias voltage switching circuit 13 to set the substrate bias voltage of the CCD 2 to the CPU. Switch to the direction to suppress blooming (step 60
1). On the other hand, the brightness of the subject is judged (step 60
0) If the subject is darker than the specified value and there is no risk of blooming, the substrate bias voltage of the CCD 2 is maintained.

Further, the above-described first to sixth embodiments can be applied to the image pickup apparatus 1 alone, or can be applied by combining arbitrary items or by applying all items in combination. .

Further, in the addition read mode, relative sensitivity can be remarkably improved as compared with the thinning-out read mode. Therefore, in addition to the improvement of the dark image quality, the accuracy of the dark preliminary measurement, the speed of the preliminary measurement, and the image pickup apparatus. In particular, it is possible to provide optimum image data for an electronic viewfinder of an electronic still camera. That is, the electronic viewfinder (Electric
The View Finder (EVF) is a mechanism for driving a CCD in a normal moving image mode, that is, a thinning-out reading mode, and displaying a real-time moving image on an electronic display device. Currently, almost all electronic still cameras use a liquid crystal monitor (display / playback). Since it is equipped with an LCD monitor), it is possible to use this liquid crystal monitor for finding. In this respect, an electronic view fan inder is generally used. Further, not only the electronic still camera but also a camera equipped with a high-magnification zoom cannot use an optical finder that is not linked to the zoom because parallax becomes large. Therefore, all electronic still cameras for general consumers (high-power zoom type) other than single-lens reflex type are now using electronic view fan inder. In addition, some of these high-magnification zoom cameras have an optical viewfinder and are limited to the viewfinder operation using only the LCD monitor, or a small LCD monitor dedicated to the viewfinder, which is separate from the LCD monitor, has an eyepiece optical system. A combination, that is, a structure provided with an electronic view fan inder similar to a so-called movie camera is used.

In an electronic still camera not equipped with an optical viewfinder, only the electronic viewfinder is used for finding. When a multi-pixel CCD having a relatively low sensitivity is used, the normal thinning readout mode is used. In the finder operation by shooting the moving image, there is a problem that finding becomes difficult in a dark scene. That is, in the case of a movie camera, there is no problem because the scenes that cannot be displayed in the electronic view fan inder are the scenes that cannot be photographed, but in the case of the electronic still camera,
For example, it is possible to shoot with a strobe, and it is necessary for the electronic view fan inder to display an image that allows the angle of view to be adjusted no matter how dark the situation.

In this respect, in the addition read mode, since all pixels contribute to image pickup, the sensitivity can be improved to the maximum level when the CCD is used, and the CCD and the electronic view fan inductor in the above addition read mode are used. By combining and, it is possible to provide a viewfinder system that can check the subject even in a dark environment.

Next, in each of the above-mentioned embodiments, the structure of the CCD for realizing the addition read mode will be described.

The following respective embodiments can be applied to the above-mentioned first to seventh embodiments, respectively.

This CCD first reads out all the signal charges of one of the two colors of color filter pixels in one column along each vertical transfer path as the first transfer path to the vertical transfer path first. After that, vertical transfer is performed while the charge read voltage is applied to the charge read electrode of a specific system among the charge read electrodes of a plurality of systems, so that lines of the same color are added on this vertical transfer path. . Further, by combining the vertical transfer and the selective read by the plurality of charge read electrodes, the signal charge that is read first and added on the vertical transfer path and the signal of the other line of another color that is read later are combined. While avoiding color mixing with electric charges, the pixels of the line including the other color filter pixel are read out to the vertical transfer path, and vertical transfer is performed while applying the electric charge read voltage to the specific electric charge read electrode as in the first color. By doing so, or by combining the line addition operation on the horizontal transfer path as the second transfer path, the line addition of the same color read out later is performed, and as a result, the same color is added by a plurality of lines. All pixels can be read out by using this function to improve the frame rate, while also improving the vertical spatial frequency reproducibility and the pixel sensitivity, thus significantly improving the image quality of moving images.
Further, it can be applied to various CCDs and can suppress increase in manufacturing cost by suppressing complication of structure.

That is, in a multi-pixel CCD, pixel charges are mixed by performing vertical transfer while voltage is being applied to a specific read electrode after reading charges to a vertical transfer path, and a high-speed high-quality moving image can be obtained. Furthermore, it is possible to improve the image quality of a moving image only by the reading method.

As will be described in detail below, the CCD
In the first embodiment, the interlaced CCD transfers the vertical transfer only in the positive direction (normal transfer) and performs addition in the horizontal transfer path. In the second embodiment, the interlaced CCD transfers vertical transfer in the reverse direction as well as the forward transfer (reverse transfer). The third embodiment is a progressive CCD.
Thus, not only the vertical transfer but also the reverse transfer is performed in the vertical transfer. The fourth embodiment is a progressive CC.
In D, vertical transfer is limited to normal transfer, and addition is performed in the horizontal transfer path. In the fifth embodiment, an interlaced complementary color line sequential CCD is used to perform vertical transfer as well as reverse transfer in reverse transfer. And
The sixth embodiment is an interlaced complementary color line sequential CCD.
Thus, vertical transfer is limited to normal transfer, and addition is performed in the horizontal transfer path.

As described above, according to the present invention, in a multi-pixel interline CCD that supports color single plates of all color filter arrays, moving image still images, and thinning, high-speed full-line by multiple line addition that avoids secondary color mixture. Pixel readout can be performed in any number of line additions without increasing the number of vertical transfer electrodes as the number of line additions increases.
This can be realized with the same minimum vertical transfer electrode configuration.

In addition, when pixels of the same color are added together, reverse point transfer in the vertical transfer path may be performed to facilitate the processing after output from the CCD.
Further, in a CCD or the like, which has a low reverse transfer efficiency, it is possible to transfer only in the forward direction.

Next, each embodiment of the present invention will be described with reference to the drawings.

First, the interlaced scan type CCD (interlaced CC) corresponding to the thinning-out, which is the first and second embodiments shown in FIGS. 1, 2, and 12 to 28, is used.
The configuration using D) will be outlined.

In this interlaced CCD,
Regardless of the number of lines to be added, the total number of vertical transfer electrodes including four systems of charge read electrodes does not increase to six systems. Specifically, the charge read electrodes are V1A, V1B, V3A, V3
There are four systems of B, and the vertical transfer electrodes are V1A, V1B, V2, V3A, V3.
There are 6 systems in total, B and V4. That is, it can be realized by an ordinary multi-pixel interlaced CCD.

That is, in the case of a multi-pixel interline CCD which is a color single plate of a normal color filter array, which also serves as a moving image still image, and which is thinned out, in the case of an interlaced CCD, the charge read electrodes are four types of V1A, V1B, V3A and V3B. Exists. Then, for example, in the Bayer system (primary color system) that uses R (red), G (green), and B (blue) filters, a combination of color filters in a certain column is RGRG ..., R is an even number, and G is an odd number. On the second horizontal line, the charge read electrode V1A is the charge read electrode of the G pixel of the odd line number that is a multiple of 5, and V1B is the remaining G pixel, that is, the charge read electrode of the remaining odd horizontal line, V3A. Is the charge read electrode of the R pixel having a horizontal line number that is a multiple of 10, and V3B is the charge read electrode of the remaining R pixel, that is, the remaining even-numbered horizontal line. By the way, in this case, the combination of color filters is GBGB ...
, G is on even-numbered horizontal lines, and B is on odd-numbered horizontal lines. That is, V1A serves as a charge readout electrode of a B pixel having a line number that is a multiple of 5, and V3A serves as a charge readout electrode of a G pixel that has a horizontal line number that is a multiple of 10. Hereinafter, in order to simplify the description, the same-color addition all-pixel reading operation will be described for the RGRG column. However, description will be made on the assumption that the same thing occurs in all pixels on the same horizontal line although the color combination differs for each column.

First, a charge read voltage is applied to V3A and V3B,
The signal charges of the R pixels as the first color, that is, the signal charges of the even lines are all read out to the vertical transfer path. After that, the voltage of V3B is returned to the original value, but vertical transfer is performed for four stages while the charge read voltage is applied to V3A. Then, since the potential well remains deep under the V3A electrode that exists every 10 lines (every 5 vertical transfer paths), the signal charges of 5 pixels of the R pixels adjacent to V3A in the upper direction are the same color in this portion. Add,
The R five-pixel added charge (5R) as the first added charge is generated. After that, in order to avoid color mixing, the 5 pixel added charge of R, that is, the 5 pixel added charge of an even line, is vertically transferred to the lower portion of the V1A electrode and temporarily saved, and then the charge read voltage is applied only to V1B to obtain 5 The G pixel as the second color other than the double spread, that is, the signal charges of the odd lines other than the multiple of 5 are read out to the vertical transfer path. Then, of these G pixels, all the signal charges at locations other than the V1A electrode where the R five-pixel added charge is located are read out. Then, the data is vertically transferred by one stage, and this time, the R five-pixel added charge is evacuated from the V1A electrode to V1A.
To the signal charge read voltage. As a result, under the V1A electrode, the G signal charge of the V1A electrode and the G signal charge on the V1A electrode which has already been read out and transferred by one stage are mixed or added for a total of two pixels. Then, similarly, the vertical transfer is performed for three stages while the charge read voltage is applied to V1A. Then, V1A existing every 10 lines (every 5 vertical transfer paths)
Since the potential well remains deep under the electrode of, the remaining 3 G pixels adjacent to V1A in the upper direction are added at this portion, and 5 pixels of the same color are added together to form G as the second added signal charge. 5 pixel addition charge (5 G) is generated.

As a result, 5G, 5R,
A state in which all pixels are read is created by repeating sky, sky, sky, 5G, 5R, sky, sky, sky .... After that, when signals are read out by repeating vertical transfer 1 stage, horizontal transfer, vertical transfer 5 stages, and horizontal transfer, the same color addition all-pixels read is realized at a frame rate of 5 times.

Next, the first embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIGS. 2 and 12 to 22.

In FIG. 1, CCD 2 is a so-called interlace interlace scan CCD for color Bayer array thinning, which is characterized by being used as a still image and moving image, and has a significantly larger number of pixels than a CCD dedicated for moving images.
While using a mechanical shutter to read all pixels individually when shooting still images, only 1/5 of all horizontal lines can be selectively thinned out and read when shooting moving images. Even if there is, it is devised to keep the frame rate (number of frames per unit time) during video high.

The CCD 2 is driven by the drive signal of the CCD drive circuit 3 and outputs an image signal. And
The drive signal given to the CCD 2 by the CCD drive circuit 3 includes vertical transfer path gate electrodes V1A, V1B, V2, V3A, V3B, V4 through which a vertical transfer path gate signal flows, as described later.
Further, a drive mode switching signal is input to the CCD drive circuit 3 from the CPU 14 which is the control means of the digital camera, and the CCD drive circuit 3 is driven by the drive mode switching signal.
Switches the driving operation mode of the CCD 2. That is, in the present embodiment, the all-pixel individual reading mode, which is the still image mode, and the thinning-out reading mode and addition reading mode, which are the moving image mode or the preliminary measurement mode, are switched.

As shown in the internal structure of FIG. 2, the CCD 2 has a photodiode 15 as photoelectric conversion means,
A vertical transfer path 16 as a first transfer path connected to the photodiodes 15 and a vertical transfer path gate signal wiring 18 connected to each of the vertical transfer paths 16 are provided. Further, in the figure, an arrow 19 indicates a forward direction which is a transfer direction to a horizontal transfer path direction (not shown). In addition, below,
The opposite direction to the horizontal transfer path direction is referred to as the reverse direction, and the transfer in the opposite direction is referred to as the reverse transfer.

The photodiodes 15 each form a pixel and are two-dimensionally arranged in a predetermined pattern. In the present embodiment, the primary color Bayer array, that is, the Bayer method, which is the primary color method, is used to display the colors in predetermined columns. The combination of filters is RGRG ..., R is on an even-numbered horizontal line and G is on an odd-numbered horizontal line, and the combination of color filters in a column adjacent to this column is GBGB ..., G is an even-numbered, and B is an odd-numbered. It is on a horizontal line.

The signal charges accumulated in the photodiodes 15 are applied to the gate electrodes of the vertical transfer paths 16 adjacent to each other by a signal charge read pulse, which is a charge read voltage having a positive potential, so that the signal charges read from the vertical transfer path 16 side. Read out.
The combination of the vertical transfer path gate electrodes that accompanies the charge reading operation of the CCD 2 is as shown in FIG.
There are four systems of signal charge readout electrodes V1A, V1B, V3A, V3B. In addition to these four systems of electrodes, vertical transfer dedicated gate electrodes V2 and V4 that do not involve charge readout operation are added to a total of six systems of vertical transfer path gate electrodes. Exist and are connected to the vertical transfer path gate signal line 18, respectively. It should be noted that such a vertical transfer path gate signal wiring 18 is currently the most common as a multi-pixel CCD having a plurality of pixels that also serves as a still image / moving image. And
In the CCD 2 of the present embodiment, as shown in FIG.
1 for every 10 pixels (lines) (G and B pixels with odd line numbers that are multiples of 5), V3A for every 10 pixels (lines) (for R and B with horizontal line numbers that are multiples of 10) (Pixel) connection, it is possible to easily realize 1/5 thinning-out reading by selectively reading signal charges only from pixels adjacent to V1A and V3A.

Note that the CCD 2 of this embodiment is merely an example, and in reality, various thinning-outs are performed depending on how many lines the electrodes corresponding to V1A and V3A are arranged in consideration of the color filter. There is a CCD corresponding to the rate.
By the way, if the number of combinations of gate electrodes accompanied by a charge read operation is easily increased in order to realize a highly complicated read operation that cannot be easily realized by the above electrode configuration, C
Not only the internal wiring of the CD becomes complicated, but also an external drive circuit is required for the number of increased vertical transfer path gate wirings, which causes adverse effects such as cost increase, device size increase, and power consumption increase. As mentioned above.

Next, the actual signal reading operation will be described from the all-pixel individual reading mode.

First, in all the photodiodes 15, unnecessary signal charges are swept to the substrate portion of the CCD by the electronic shutter operation, and the accumulation of the signal charges is started all at once for the exposure through the optical system (not shown). To do. Then, when the exposure is completed after a predetermined exposure time elapses, the light path to the photodiode 15 is blocked by a light-shielding device such as a mechanical shutter (not shown), and each photodiode 15 is in a dark state until all signal charges are read out. Held in.

Next, the states of charge reading and vertical transfer will be described with reference to FIGS. 12 and 13. 12 and 13 describe the state of charge reading and vertical transfer in the leftmost column in FIG. 2, that is, the vertical transfer waveform and potential, but in the following description, all other columns including adjacent columns are described. It is assumed that a similar operation occurs in a column. That is, charge reading and vertical transfer are performed in horizontal line units. Further, in these FIGS. 12 and 13, the waveforms with V1A to V4 indicate the voltage waveforms of the respective vertical transfer path gate signals, and the waveforms with A to G shown in the direction orthogonal to the voltage waveforms indicate the vertical transfer. It shows the potential of the road. In the figure, 21 is a charge read pulse, and 22 is a read signal charge. First, as an initial state, each vertical transfer path gate signal and potential state are shown in FIG.
From the state shown in A of 2 to V3A, as shown in B of FIG.
A charge read pulse 21 is applied to V3B. Then, C in FIG.
As shown in, all the signal charges on the even lines are read out to the vertical transfer path. Next, by applying a predetermined voltage to V1A to V4, as shown in D to G of FIG. 12, the read signal charges 22 are vertically transferred by one stage, and the signal charges of the lowermost line are transferred to a horizontal transfer path (not shown). Forward. After that, all the signal charges (pixel charges) of one line are read out by horizontal transfer. Then, one-stage vertical transfer and horizontal transfer are repeated to read all the signal charges of even-numbered lines individually and output them to the outside of the CCD 2 to complete the reading of the first field.

Subsequently, from each vertical transfer path gate signal and potential state shown in A of FIG. 13, a charge read pulse 21 is applied to V1A and V1B as shown in B of FIG. Then, as shown in C of FIG. 13, all the signal charges on the odd line are read to the vertical transfer path. Then, V1A ~ V4
By applying a predetermined voltage to, as shown in D to E of FIG.
The read signal charges 22 are vertically transferred by 1/2 stage, and further,
As shown in F to I of FIG. 13, the read signal charges 22 are vertically transferred by one stage, and the signal charges of the lowermost line are transferred to a horizontal transfer path (not shown). After that, all the signal charges (pixel charges) of one line are read out by horizontal transfer. Then 1
By repeating vertical transfer and horizontal transfer, all the signal charges of the odd lines are individually read and output to the outside of the CCD 2
Finish reading the field.

In this way, C over two fields
By reading the signal charges on the CD2, the read operation in the all-pixel individual read mode is completed. As schematically shown in FIG. 20, the operation of the all-pixel individual reading mode is a mode in which all pixels are individually read by using two fields by using the external light-shielding means, and one frame is an even line and an odd number. Since the line is divided into two parts and the operation of a physical light-shielding means such as a mechanical shutter is involved, and the frame rate is very slow,
Although not suitable for moving images, all the pixels of a so-called multi-pixel CCD are independently read out, so that an extremely high-definition image that is satisfactory as a still image can be obtained.

Next, a 1/5 decimation mode which is normally performed by using the CCD 2 of this embodiment, that is, a decimation read mode in which 4/5 lines are thinned and 1/5 lines are read out will be described. This ⅕ thinning mode is mainly used for shooting moving images, and consideration is given to how to combine the selected color filters, and it is considered that all the color filter signals of R, G, and B are aligned in one field. Since RGB are aligned in one field by one exposure and reading, it is not necessary to perform a light-shielding operation by a light-shielding device such as a mechanical shutter when reading signal charges. In this mode, since the charge read pulse is applied only to V1A and V3A, other photodiodes 15, that is, pixels, which are not connected to V1A and V3A, are not read. That is, for example, in FIG. 2, R0, G0, G
Only the photodiodes 15, that is, the pixels, on the shaded horizontal lines such as 5, B5, R10, G10, ... Are selectively read out.

The read operation will be described below with reference to FIG. FIG. 14 describes the state of charge reading and vertical transfer in the leftmost column in FIG. 2, but in the following description, similar operations occur in all other columns including adjacent columns. I shall. That is, charge reading and vertical transfer are performed in horizontal line units. Further, in FIG. 14, 21a is a charge read pulse applied to V3A, 21b is a charge read pulse applied to V1A, and 22a is
Signal charge of the selected and read RG line, 22b
Is the signal charge of the GB line which is also selected and read.

First, as an initial state, a charge read pulse 21a is applied to V3A from the state where each vertical transfer path gate signal and potential state are shown in FIG. 14A, as shown in FIG. 14B. Then, as shown in C of FIG. 14, the signal charges 22a of the line including the pixel of R every 10 lines such as RO, R10, R20, ... Are read out to the vertical transfer path. Then, a predetermined voltage is applied to V1A to V4 to reduce the read signal charge 22a to 1/2 as shown in D to E of FIG.
Vertical transfer, and as shown in FIG. 14F, V1A
A charge read pulse is applied to. Then, as shown in G of FIG. 14, the signal charge 22b of the line including the G pixel is read out to the vertical transfer path every 10 lines similarly to G5, G15 ..., B5, B15. In this state, the signal charges 22a and 22b are present in only two of the five charge holding portions of the vertical transfer path, and the rest are empty. Therefore, after this, the vertical transfer path 3
After the stage transfer, the horizontal transfer, the horizontal transfer end, the vertical transfer path two stages transfer, and the horizontal transfer ... Repeatedly, the signal charges are sequentially transferred to the horizontal transfer path on the vertical transfer path.

As schematically shown in FIG. 21, in this moving image mode operation, the frame rate is five times as fast as that in the all-pixel individual reading mode, but since the lines are thinned out, naturally, this moving image is generated. The spatial frequency reproducibility in the vertical direction of the image obtained by the mode is significantly deteriorated.

Next, the all-pixel read mode for adding five lines of the same color and the addition read mode which is a moving image mode according to the present embodiment will be described with reference to FIGS. 15 and 16.

In FIGS. 15 and 16, FIG.
The state of charge reading and vertical transfer in the leftmost column is described, but in the following description, it is assumed that the same operation occurs in all other columns including adjacent columns. That is, addition, charge reading, and vertical transfer are performed in horizontal line units. In addition, V1A to V4 shown in FIG.
16 shows the voltage waveform of each vertical transfer path gate signal marked with
The voltage waveforms of the vertical transfer path gate signals denoted by V1A to V4 shown in FIG. On the other hand, FIG. 15 shows the first half part of the waveform showing the potential state of the vertical transfer path with A to T shown in the direction orthogonal to this voltage waveform, and FIG.
6 shows the latter half part.

First, as an initial state, from the state in which each vertical transfer path gate signal and potential state are shown in FIG. 15A, to V3A and V3B as shown in FIG. By applying the pulses 31a and 31b, only the signal charges 33 on the even lines are all read out to the vertical transfer path. Next, as shown in C to H of FIG. 15, application of the charge read pulse 31b of V3B is stopped, but vertical transfer is performed in the positive direction for four stages while the charge read pulse 31a is added to V3A. Then, even if the vertical transfer is performed, since the potential wells are deeper in the electrode portions of V3A every 10 lines, that is, every 5 stages, the signal charges (pixel charges) of the read even lines are below V3A. In the charge holding portion, signal charges of 5 pixels of the same color of R pixels are mixed, that is, added. Then, in a state where the application of the V3A charge read pulse 31a is stopped, as shown by I in FIG. 15 and I in FIG. 16, a signal charge for five pixels is added per one stage to obtain a first added charge. The five-pixel mixed charge 34 is held.

Then, from the state shown in I of FIG. 15 and I of FIG. 16, a predetermined voltage is applied to V1A to V4, and
As shown in J to L, the 5-pixel mixed charges are vertically transferred by 2.5 stages in the horizontal transfer path direction, and the 5-pixel mixed charges in the even lines are temporarily saved under the V1A electrode. From this state,
As shown by M of 6, a charge read pulse 32b is applied to V1B,
4/5 of the signal charge on the odd line is read. Next, as shown at N in FIG. 16, after the application of the charge read pulse 32b at V1B is stopped, a predetermined voltage is applied to V1A to V4, and as shown in OR at FIG. The 5 pixel mixed charge 34 and the signal charge of 4/5 of the odd line are vertically transferred by one stage toward the horizontal transfer path.

Then, as shown in S of FIG. 16, a charge read pulse 32a is applied to V1A, and the remaining 1/5 of the odd line is supplied.
The line charge is read out to the vertical transfer path. Then, in FIG.
After the application of the charge read pulse 32a of V1A is stopped, as shown in T of FIG. 16, under the electrode of V1A shown in T of FIG. 16, adjacent two pixels of the odd lines are mixed and the remaining odd The signal charge for one pixel is read and held in the charge holding portion of the line. In this state, 5R, 2
In the repetitive form of G, G, G, G, 5R, 2G, G, G, G, ..., The signal charges of all pixels are partially added to the vertical transfer path and read.

Further, the subsequent vertical transfer and horizontal transfer are performed as shown in FIGS. That is,
FIG. 17A shows the state of the vertical transfer path indicated by T in FIG. Further, 41 in FIGS. 17 to 19 indicates a vertical transfer path, and 42 indicates a horizontal transfer path. Then, at the stage of FIG. 17A, as a result of the process of the above-described read operation, the even-numbered line 5 pixel mixed charge (R0 + R2 + R4 + R6 + R8) 34 is already in the horizontal transfer path 42. Existing. Therefore, as shown in FIG. 17B, this 5 pixel mixed charge (R0
+ R2 + R4 + R6 + R8) 34 is read by horizontal transfer, and then
As shown in FIG. 7 (C), vertical transfer is performed while the horizontal transfer is stopped, and addition of odd lines, that is, pixel mixing is performed on the horizontal transfer path. Further, in the state shown in FIG. 17C, since the signal charges (G1 + G3) on the horizontal transfer path are the end portions of the screen,
Insufficient summation results in incomplete mixed pixel count. Therefore, as shown in FIG. 18D, this charge (G1 +
G3) is horizontally transferred and then, as shown in FIG. 18 (E), vertical transfer is performed for one stage, and 5 pixel mixed charges (R10 + R12 + R14 + R16 +) of an even line in which 5 pixels are added are added. R1
8) Transfer 34 to the horizontal transfer path. Then, as shown in FIG. 18 (F), this five-pixel mixed charge (R10 + R12 + R14 + R16 +
R18) 34 is output by horizontal transfer. Then, in FIG.
As shown in (G), one stage of vertical transfer is performed, and the signal charge (G5 + G7) obtained by adding the two pixels of the odd line is transferred to the horizontal transfer path. Next, as shown in FIGS. 19 (H to I), three stages of vertical transfer are continuously performed before horizontal transfer is performed, and odd-numbered lines are added on the horizontal transfer path.
A 5-pixel mixed charge (G5 + G7 + G9 + G11 + G13) 44, which is a 5-pixel addition signal charge, is generated as the second added charge.

After outputting the signal charges by horizontal transfer, the operations of one-stage vertical transfer, horizontal transfer, four-stage vertical transfer, horizontal transfer ... . In this way, after all the pixels are partially added to the vertical transfer path 41 and read out, the vertical transfer path 41 is set to 1
As a result of repeating the transfer operation in four stages, all pixel signals can be read at a frame rate five times that of a still image.

FIG. 22 schematically shows a combination of pixels finally added and read in this addition read mode. The original arrangement of signal charges is G1 to 3 → R0 to 8 → G5 to 13 → R10 to 18 → G1.
5 to 23 → R20 to 28 ... However, as can be seen from FIG. 22, in the present embodiment, R0 to 8 → G1 to 3 → R
The addition signal, which is a mixed charge of 5 pixels, is output in the order of 10 to 18 → G5 to 13 → R20 to 28 → G15 to 23, and the positional relationship between the even lines and the odd lines is reversed. Such a phenomenon is caused by a component outside the CCD 2 arranged in the subsequent stage of the CCD 2 according to the present embodiment, which controls image processing and the like, for example, a line buffer as a processing device capable of recording image data for one line. Is provided, the previously output line signal is temporarily held, the next line signal is allowed to pass first, and the signal of the even line and the signal of the odd line are exchanged, whereby the compensation can be performed.

Further, in this embodiment, the primary color Bayer array has been described as an example, but the present invention is not limited to this, and what kind of filter array is provided as long as one vertical line color filter is two sets or less. However, it is applicable. That is, it can be applied to almost all existing filter arrays other than the filter array shown in the fourth embodiment.

As described above, according to the present embodiment, in the interlaced CCD, in almost all the color filter arrays, the high-frame-rate same-color-added all-pixels can be used by simply changing the charge reading method with the current configuration. Reading can be realized. As a result, the image quality of the moving image can be significantly improved without increasing the cost or while suppressing the cost increase, and the high-sensitivity effect of the additive reading allows the shooting conditions of the moving image to be improved especially in a dark scene. It can be greatly expanded. Further, even if the number of lines added increases with the increase in the number of pixels of the CCD, the number of vertical transfer electrodes does not change, and the increase in cost can be suppressed.

Further, in the present embodiment, in the vertical transfer path, it is sufficient to transfer the signal charges only in the positive direction which is the horizontal transfer path direction, and it is not necessary to perform the reverse transfer. Therefore, the transfer efficiency of the reverse transfer is significantly reduced. It can also be applied to the CCDs, and the versatility can be improved.

Next, the second embodiment will be described with reference to FIG.
It will be described with reference to FIGS. The internal configuration of the CCD 2 of the second embodiment and the basic operation including driving of the CCD 2 are exactly the same as those of the first embodiment shown in FIGS. In this embodiment, in the all-pixel read drive for adding 5 lines of the same color, the line replacement processing by the components outside the CCD 2 necessary in the first embodiment is devised by devising the driving method of the CCD 2. It can be unnecessary.

The addition read mode (same-color 5 line addition all-pixel read mode) according to the second embodiment will be described below with reference to FIGS. 24 and 25. 24 and 25, the state of charge reading and vertical transfer in the leftmost column in FIG. 2 is described, but in the following description, the same applies to all other columns including adjacent columns. It is assumed that the operation is occurring. That is, addition, charge reading, and vertical transfer are performed in horizontal line units. The voltage waveform of each vertical transfer path gate signal with V1A to V4 shown in FIG. 24 and the voltage waveform of each vertical transfer path gate signal with V1A to V4 shown in FIG. 25 are the same. . On the other hand, FIG. 24 shows the first half portion and FIG. 25 shows the latter half portion of the waveforms showing the potential states of the vertical transfer paths denoted by A to S shown in the direction orthogonal to this voltage waveform.

First, as an initial state, charge transfer pulses 31a and 31b are applied to V3A and V3B, respectively, from the state shown in FIG. 24A for each vertical transfer path gate signal and potential state, as shown in FIG. 24B. Then, only the signal charges of even lines are read out to the vertical transfer path. Next, as shown in C to H of FIG. 24, the application of the charge read pulse 31b of V3B is stopped, but the charge read pulse 31a is added to V3A,
Vertical transfer is performed in the positive direction for four steps. Then, even if the vertical transfer is performed, since the potential wells are deeper in the electrode portions of V3A every 10 lines, that is, every 5 stages, the signal charges (pixel charges) of the read even lines are below V3A. In the charge holding portion, signal charges of 5 pixels of the same color of R pixels are mixed, that is, added. Then, with the application of the V3A charge read pulse 31a stopped, as shown in I of FIG. 24 and I of FIG. 25, a five-pixel mixed charge 34 in which signal charges of five pixels are added per stage is generated. It will be held.

Then, from the state shown in I of FIG. 24 and I of FIG. 25, a predetermined voltage is applied to V1A to V4, and
As shown in J to K, the five-pixel mixed charge 34 is vertically transferred by 2.5 stages in a direction opposite to the horizontal transfer path, so to speak, reverse transfer,
The 5 pixel mixed charge 34 of the even line is temporarily saved under the V1A electrode. From this state, as shown in L of FIG. 25, V1B
A charge read pulse 32b is applied to the read signal to read 4/5 of the signal charge on the odd line. Then, as shown in M of FIG.
After stopping the application of this V1B charge read pulse 32b, V1A
To V4, a predetermined voltage is applied, and as shown in N to O of FIG.
The signal charge of / 5 is vertically transferred by one stage in the positive direction, that is, toward the horizontal transfer path.

Then, as shown in P of FIG. 25, the charge read pulse 32a is applied to V1A, and the remaining 1/5 of the odd line is supplied.
The signal charge of the line is read out to the vertical transfer path. Then, under the electrode of V1A shown in P of FIG. 25, adjacent two pixels of the odd line are mixed, and the signal charge for one pixel is read out and held in the charge holding portion of the remaining odd line. It will be in the state of being. From this state, as shown in Q to R of FIG. 25, each signal charge is vertically transferred by three stages in the positive direction while the charge read pulse 32a is applied to V1A. Then, as shown in R of FIG. 25, in the charge holding portion under the electrode of V1A,
Signal charges of 5 pixels of the same color of G pixel are added to generate a 5 pixel mixed charge 44. Then, V1A charge read pulse 3
After the application of 2a is stopped, as shown in S of FIG. 25, the signal charges of the even lines and the odd lines of each stage are added up by 5 pixels in the same color, and a 5-pixel mixed charge 34,
44 is held.

Further, the subsequent vertical transfer and horizontal transfer are performed as shown in FIGS. That is,
FIG. 26A shows the state of the vertical transfer path shown at S in FIG. 26 to 28, reference numeral 41 indicates a vertical transfer path, and 42 indicates a horizontal transfer path. 24 and 2
In the step shown in FIG. 5, a plurality of lines are added together in the vertical transfer path 41, but at the end, for example, the lowermost line 43 on the horizontal transfer path 42 side, all effective pixels cannot be added together. An incomplete pixel mixture situation has occurred. Therefore,
First, the incomplete mixed pixels on the line 43 are read out by vertical transfer and horizontal transfer. Thereafter, as shown in FIG. 26B, the first effective 5-pixel mixed line is transferred to the horizontal transfer path. Since there are three stages of empty charge holding portions above the five-pixel mixed line, horizontal transfer is not performed immediately at this point, and FIGS. 26C, 27D, and 27E are used. As shown in, vertical transfer is performed for three stages. That is, when the transfer of the first valid line to the horizontal transfer path is included, four stages of vertical transfer are performed before horizontal transfer. Then, as shown in FIG. 27 (F), horizontal transfer is performed to read the first effective 5-pixel mixed line, and then, as shown in FIG. 28 (G), 1
Vertical transfer is performed for the number of steps, and the next effective 5 pixel mixed line is transferred to the horizontal transfer path. Then, this time, as shown in FIG. 28H, since the effective line exists immediately above, horizontal transfer is immediately performed, and vertical transfer for one stage is performed as shown in FIG. 28I.

Thereafter, four-stage vertical transfer, horizontal transfer,
The operation of one-stage vertical transfer, horizontal transfer, ... Is repeated to read the image signal to the outside. In this way, after all pixels have been read out on the vertical transfer path and the same colors have been added together, the vertical transfer path is repeatedly transferred in the forward direction by repeating four steps and one step, resulting in 5 All pixel signals can be read at a double frame rate.

Note that FIG. 23 schematically shows a combination of pixels finally added and read in this addition read mode. As described above, in the present embodiment, by performing the reverse transfer operation that is the reverse of the vertical transfer direction in the process of charge reading, the line reading order can be corrected, and the line replacement by the external component or the like becomes possible. There is no need for treatment and it is easy to reduce costs.

Further, in the second embodiment, the line addition operation is completed not only on the even lines but also on the odd lines on the vertical transfer path. However, like the first embodiment,
The addition operation of odd-numbered lines can be realized by combining addition on the vertical transfer path and addition on the horizontal transfer path.

Also in the first embodiment, the odd line addition operation is performed as in the second embodiment.
It can also be completed on the vertical transfer path. That is, in each of the embodiments described in the present application, the addition operation of the odd-numbered lines may be completed on the vertical transfer path, and is realized by combining the addition on the vertical transfer path and the addition on the horizontal transfer path. be able to.

Next, the structure using the progressive scan type CCD (progressive CCD) corresponding to the thinning-out, which is the third and fourth embodiments shown in FIGS. 29 to 40, will be outlined.

In this progressive CCD, in the case of a three-phase vertical transfer structure, in the case of normal thinning-out, the number of charge read electrodes is two systems of V2A and V2B, and the vertical transfer electrodes are V1, V2A, V2B,
In order to realize this configuration, the total of 4 systems of V3 are 4 systems of charge read electrodes V2A, V2B, V2C, V2D, and the vertical transfer electrodes are 6 systems of these charge read electrodes plus V1 and V3. It needs to be increased, but no matter how many lines are added, the number of lines does not increase.

Further, in the case of the four-phase vertical transfer structure, the number of charge read electrodes is two systems of V2A and V2B in the normal thinning correspondence,
The total number of vertical transfer electrodes is V1, V2A, V2B, V3, and V4, but there are 5 lines of charge read electrodes to realize this structure.
There are 4 systems of 2A, V2B, V3, and it is necessary to increase the number of vertical transfer electrodes to 7 systems in which V1, V3, V4 are added to these charge readout electrodes. The number of lines will not increase.

That is, in the case of a progressive CCD,
The charge read electrodes are provided with four systems of V2A, V2B, V2C and V2D. Then, a combination of color filters in a certain column is RGRG.
, Where R is on an even-numbered line and G is on an odd-numbered horizontal line, the charge read electrode V2A is an R pixel with a line number that is a multiple of 10, and V2B is the remaining R pixel, that is, the remaining even-numbered horizontal line. It is assumed that V2C is a charge readout electrode, V2C is a G pixel of an odd line number that is a multiple of 5, and V2D is a remaining G pixel, that is, a charge readout electrode of the remaining even-numbered horizontal lines.

First, a charge read voltage is applied to V2A and V2B,
All the R pixel pixels, that is, the signal charges of the even lines are read to the vertical transfer path. After that, the voltage of V2B is returned to the original value, but vertical transfer is performed for eight stages while the charge read voltage is applied to V2A. Then, since the potential well remains deep under the V2A electrode that exists every 10 lines, the signal charges of the five R pixels adjacent to the upper direction of V2A are added in the same color in this portion, and the first added charge is added. Charge of 5 pixels of R as
(5R) is generated.

After this, the 5 pixel added charge of R, that is, the 5 pixel added charge of the even-numbered line is transferred in the direction opposite to the 4-stage horizontal transfer path and saved, and then the charge read voltage is applied to V2C and V2D. Is added to read out all the signal charges of the G pixel, that is, the odd-numbered lines to the vertical transfer path. Similar to the case of the even lines, the voltage of V2D is returned to the original value, but the vertical transfer is performed for eight stages while the charge read voltage is applied to V2C. Then, the signal charges of five G pixels adjacent to the upper side of the V2C electrode in the upward direction are added together in the same color, and a five-pixel added charge of G (5G) as the second added charge is generated.

As a result, 5G, 5R, sky, sky, sky, sky, sky, sky, sky, sky, 5
In the G, 5R, sky, sky ... state, a state in which all pixels are read is created. After that, if the pixel signals are read out of the CCD by repeating 1-stage vertical transfer, horizontal transfer, 9-stage vertical transfer, horizontal transfer, ... it can.

Next, FIG. 29 shows a third embodiment of the present invention.
It will be described with reference to FIGS. The configuration of the third embodiment is similar to that of the first embodiment, and the configuration diagram is the same as that of FIG. 1. However, in the present embodiment, as shown in the internal structure of FIG. As an example, the present invention is applied to a so-called color Bayer array thinning-compatible interline type progressive scan CCD.

That is, in the third embodiment, C
The CD2 is a color Bayer array interline progressive scan CCD. This CCD 2 features both still images and moving images. Since it has a significantly larger number of pixels than CCDs used exclusively for moving images, all pixels are read out individually in order when shooting still images, but 5 pixels in a horizontal line when shooting moving images. The same colors are added and read out,
Even if the number of pixels is large, it is devised to maintain a high frame rate during moving images.

The CCD 2 is driven by the CCD drive circuit 3 and outputs an image signal. And CC
The drive signals given to the CCD 2 by the D drive circuit 3 include vertical transfer path gate signals V1, V2A, V2B, V2C, V2D, V3, which will be described later. In addition, a drive mode switching signal is input to the CCD drive circuit 3, and the drive mode switching signal causes
The CCD drive circuit 3 switches the drive operation mode of the CCD 2.

Further, the CCD 2 has a photodiode 15 as a photoelectric conversion means, as shown in the internal structure of FIG.
And the first CC connected to these photodiodes 15.
A vertical transfer path 16 which is D and a vertical transfer path gate signal wiring 18 connected to each of the vertical transfer paths 16 are provided. Further, in the figure, an arrow 19 indicates a forward direction which is a vertical transfer direction to a horizontal transfer path direction which is a second CCD (not shown).

Further, the photodiodes 15 respectively form pixels and are two-dimensionally arranged in a predetermined pattern. In the present embodiment, the primary color Bayer array, that is, the Bayer system which is the primary color system, is used to display the colors in predetermined columns. The combination of filters is RGRG ..., R is on an even-numbered horizontal line and G is on an odd-numbered horizontal line, and the combination of color filters in a column adjacent to this column is GBGB ..., G is an even-numbered, and B is an odd-numbered. It is on a horizontal line.

The signal charges accumulated in the photodiode 15 are transferred to the vertical transfer path 16 side by applying a charge read pulse, which is a charge read voltage having a positive potential, to the gate electrodes of the vertical transfer paths 16 adjacent to each other. Read out. Then, as shown in FIG. 29, the combination of the gate electrodes of the vertical transfer paths accompanied by such charge reading operation of the CCD 2 is V2.
There are four systems, A, V2B, V2C, and V2D, and the electrodes for these four systems have a gate electrode V for exclusive use of vertical transfer without charge read operation.
In addition to 1, V3, there are a total of 6 systems of vertical transfer path gate electrodes, each of which is connected to the vertical transfer path gate signal line 18.

Note that the CCD 2 of the present embodiment only shows a configuration of 5-line addition as an example, and in practice, electrodes corresponding to V2A and V2C are arranged on every line while considering the color filter. Therefore, it is possible to realize CCDs with various line addition numbers. In the present embodiment, no matter how the number of lines added increases, the number of vertical transfer path gate electrodes does not increase, and the cost can be suppressed.

Next, the actual signal read operation will be described from the all-pixel individual read mode.

First, all the photodiodes 15 are swept away by the electronic shutter operation to undesired signal charges to the substrate portion of the CCD, and start accumulating signal charges all at once for exposure through the optical system. Then, when the exposure is completed after a predetermined exposure time elapses, the signal charges of all the photodiodes 15 are read out to the vertical transfer paths 16.

Next, referring to FIG. 30, the states of charge reading and vertical transfer will be described. Although FIG. 30 illustrates how charges are read out and vertically transferred in the leftmost column of FIG. 29, in the following description, similar operations occur in all other columns including adjacent columns. I shall. That is, charge reading and vertical transfer are performed in horizontal line units. Further, in FIG. 30, the waveforms with V1 to V3 show the voltage waveforms of the respective vertical transfer path gate signals, and the waveforms with A to I shown in the direction orthogonal to this voltage waveform are the potentials of the vertical transfer paths. Is shown. Also,
In the figure, 51a, 51b, 51c and 51d are charge read pulses, and 52 is the read signal charge. First, as an initial state, each vertical transfer path gate signal and potential state are changed from the state shown in A of FIG. 30 to V2 as shown in B of FIG.
Charge read pulses 51a, 51b, 51c and 51d are applied to A, V2B, V2C and V2D. Then, as shown in C of FIG. 30, all the signal charges 52 are read out to the vertical transfer path. Then, V1A ~ V4
30 is applied with a predetermined voltage, and as shown in D to I of FIG.
The read signal charges 52 are vertically transferred by one stage, and the signal charges of the lowermost line are transferred to a horizontal transfer path (not shown). After that, all the signal charges of one line are read out by horizontal transfer. Then, one-stage vertical transfer and horizontal transfer are repeated, and all the signal charges of the horizontal lines are sequentially read from the head one by one, and are output to the outside of the CCD 2.
The reading in the all-pixels individual reading mode ends. That is, the all-pixel individual reading mode is a mode in which all pixels are individually read in order from the beginning in one frame, and the number of pixels in one frame is very large, resulting in a very slow frame rate and not suitable for moving images. However, multi-pixel CCD
Since all of the pixels are read independently, an extremely high-definition image that is perfect as a still image can be obtained.

Next, the addition read mode according to the present embodiment will be described with reference to FIGS. 31 and 32.

In FIG. 31 and FIG. 32, FIG.
The state of charge reading and vertical transfer in the leftmost column of 9 is described, but in the following description, it is assumed that the same operation occurs in all other columns including the adjacent column. That is, addition, charge reading, and vertical transfer are
It is performed in units of horizontal lines. In addition, V1 to V3 shown in FIG.
32 shows the voltage waveform of each vertical transfer path gate signal with
The voltage waveforms of the respective vertical transfer path gate signals denoted by V1 to V3 are the same. On the other hand, FIG. 31 shows the first half part of the waveform showing the potential state of the vertical transfer path with A to Y shown in the direction orthogonal to this voltage waveform, and FIG.
Shows the latter half.

First, as an initial state, charge transfer pulses 51a and 51b are applied to V2A and V2B, respectively, from the state shown in FIG. 31A for each vertical transfer path gate signal and potential state, as shown in FIG. 31B. Then, only the signal charges 52 of even lines are read out to the vertical transfer path. Next, FIG.
As shown in C to K, the application of the charge read pulse 51b for V2B is stopped, but the vertical transfer is performed in the positive direction for eight steps while the charge read pulse 51a is added to V2A. Then, even if vertical transfer is performed, since the potential wells are deeper in the V2A electrode portions at every 10th stage, the read-out even line signal charges (pixel charges) are stored in the charge holding unit below V2A. The signal charges of 5 pixels of the same color of the R pixel are mixed, that is, added. Then, in the state where the application of the V2A charge read pulse 51a is stopped, as shown in L of FIG. 31 and L of FIG. 32, the 5 pixel mixed charge 54 in which the signal charges of 5 pixels are added per stage is generated. It will be held.

Then, from the state shown by L in FIG. 32,
By applying a predetermined voltage to V1 to V3, as shown in M to R of FIG. 32, the five-pixel mixed charge 54 is vertically transferred in the opposite direction of the horizontal transfer path by four stages, that is, reversely transferred, and below the V2B electrode. The 5-pixel mixed charge 54 is temporarily saved. From this state,
As indicated by S in FIG. 5, charge read pulses 51c and 51d are applied to V2C and V2D.
And the signal charges on the odd lines are read to the vertical transfer path. Next, as shown in T to X of FIG. 32, the V2D charge read pulse 51d is applied while the V2C charge read pulse 51c is added.
In the state where the application is stopped, a predetermined voltage is applied to V1 to V3 to vertically transfer each signal charge 52 of the vertical transfer path toward the horizontal transfer path by eight stages in the positive direction. Then, even if the vertical transfer is performed, the potential wells are deep in the V2C electrode portions at every tenth stage, so that the signal charges on the odd-numbered lines that have been read out are stored in the G pixel pixel in the charge holding portion below V2C. The signal charges of 5 pixels of the same color are mixed, that is, added. Then, in a state where the application of the V2C charge read pulse 51c is stopped, as shown in Y of FIG. 32, a state in which a 5-pixel mixed charge 55 in which signal charges of 5 pixels are added per one stage is held. Become. Then, in the state shown in Y of FIG. 32, as shown in FIG. 33A, immediately above the mixed charge 55 of the five pixels of the odd line, the five pixels of the even line previously read and mixed. There is a mixed charge 54. Therefore,
As shown in FIGS. 33B and 33C, after the first five-pixel mixed charge 55 is read out and output to the horizontal transfer path, FIG.
As shown in FIG. 35 (I), the five-pixel mixed charges 54 and 55 of the same color can be read by repeating 1-stage vertical transfer, horizontal transfer, 9-stage vertical transfer, horizontal transfer, ....

In this embodiment, the primary color Bayer array has been described as an example, but the present invention is not limited to this, and what kind of filter array is provided as long as one vertical line color filter is two or less. However, it is applicable. That is, it can be applied to almost all existing filter arrays other than the filter array shown in the fourth embodiment.

That is, in the progressive CCD as in this embodiment, the same effect as above can be obtained with any color filter array by using four read electrodes. Further, in this configuration, the number of vertical transfer electrodes is increased by two systems as compared with the normal configuration, but C
Even if the number of lines added increases with the increase in the number of pixels of the CD, the number of vertical transfer electrodes does not increase any more, and an increase in cost can be suppressed.

Further, in this embodiment, after the even-numbered-line 5-pixel mixed charge is generated on the vertical transfer path, the reverse transfer is performed by the method shown in the second embodiment, that is, on the vertical transfer path. The even / odd inversion of the output line order is compensated for inside the CCD2. However, as in the case of the fourth embodiment described below, as in the case of the first embodiment, only vertical transfer in the positive direction is used for all of the above. The line order can be compensated by a component outside the CCD that realizes pixel mixture and controls image processing. Further, also in this embodiment, similarly to the second embodiment, the pixel mixture on the odd line side can be performed on the horizontal transfer path.

Next, FIG. 36 shows a fourth embodiment of the present invention.
Through FIG. 40.

The basic structure including the internal structure of the CCD 2 of the fourth embodiment and the driving of the CCD 2 is shown in FIG.
The third embodiment is the same as that of the third embodiment shown in FIG. In addition, in this embodiment, in the vertical transfer path, it is sufficient to transfer the signal charges only in the positive direction, which is the horizontal transfer path direction, and it is not necessary to perform the reverse transfer. In addition, the versatility can be improved, and the time required for the read operation can be slightly shortened as compared with the third embodiment by incorporating the addition in the horizontal transfer path.

Next, the moving image mode according to the present embodiment, that is, the addition read mode will be described with reference to FIGS.
Will be described with reference to.

In these FIG. 36 and FIG. 37, FIG.
The state of charge reading and vertical transfer in the leftmost column of 9 is described, but in the following description, it is assumed that the same operation occurs in all other columns including the adjacent column. That is, addition, charge reading, and vertical transfer are
It is performed in units of horizontal lines. In addition, V1 to V3 shown in FIG.
37 and the voltage waveforms of the vertical transfer path gate signals marked with
The voltage waveforms of the respective vertical transfer path gate signals denoted by V1 to V3 are the same. On the other hand, FIG. 36 shows the first half part of the waveform showing the potential state of the vertical transfer path with A to U shown in the direction orthogonal to this voltage waveform, and FIG.
Shows the latter half.

First, as an initial state, charge transfer pulses 51a and 51b are applied to V2A and V2B, respectively, from the state shown in FIG. 36A for each vertical transfer path gate signal and potential state, as shown in FIG. 36B. Then, only the signal charges 52 of even lines are read out to the vertical transfer path. Next, in FIG.
As shown in C to K, the application of the charge read pulse 51b for V2B is stopped, but the vertical transfer is performed in the positive direction for eight steps while the charge read pulse 51a is added to V2A. Then, even if vertical transfer is performed, since the potential wells are deeper in the V2A electrode portions at every 10th stage, the read-out even line signal charges (pixel charges) are stored in the charge holding unit below V2A. The signal charges of 5 pixels of the same color of the R pixel are mixed, that is, added. Then, in the state where the application of the V2A charge read pulse 51a is stopped, as shown in L of FIG. 36 and L of FIG. 37, the five-pixel mixed charge 54 in which the signal charges of five pixels are added per stage is generated. It will be held.

From the state indicated by L in FIG. 37,
By applying a predetermined voltage to V1 to V3, as shown in M to R of FIG. 37, the five-pixel mixed charge 54 is vertically transferred by six stages in the horizontal transfer path direction, that is, in the positive direction, and five pixels are mixed under the V2B electrode. Charge 54
To evacuate. From this state, as shown by S in FIG. 37, the charge read pulses 51c and 51d are applied to V2C and V2D to read the signal charges of the odd lines to the vertical transfer paths. Then, as shown at T in FIG. 37, the application of the charge read pulses 51c and 51d of V2C and V2D is stopped. In this state, U in FIG.
As shown in, except for a part of the bottom, 5R, G, G,
In the repeating form of G, G, G, 5R, G, G, G, G, G, ..., The signal charges of all pixels are read out to the vertical transfer paths.

Further, the subsequent vertical transfer and horizontal transfer are performed as shown in FIGS. 38 and 39. That is, FIG. 38A shows the state of the vertical transfer path indicated by U in FIG. Further, 61 in FIGS. 38 and 39 indicates a vertical transfer path, and 62 indicates a horizontal transfer path. And this FIG.
At the stage of (A), as a result of the process of the above-mentioned read operation, the horizontal transfer path 62 already has the 5 pixel mixed charges (R0 + R2 + R4 + R6 + R8) 63 of even lines. Therefore,
As shown in FIG. 38 (B), this 5 pixel mixed charge (R0 + R2
After reading + R4 + R6 + R8) 63 by horizontal transfer,
As shown in (C), vertical transfer is performed while horizontal transfer is stopped, and addition of odd lines, that is, pixel mixing is performed on the horizontal transfer path. Further, in the state shown in FIG. 38 (C), the signal charges (G1 + G3) on the horizontal transfer path are at an edge portion of the screen, and therefore the addition is insufficient, resulting in an incomplete mixed pixel number. Therefore, as shown in FIG. 39 (D), this signal charge (G1 + G
After horizontal transfer of 3), as shown in FIG. 39 (E), vertical transfer for one stage is performed, and 5 pixel mixed charges (R10 + R12 + R14 + R16 +) of even lines in which 5 pixels are added are added. R1
8) Transfer 63 to the horizontal transfer path.

Then, as shown in FIG.
The pixel mixed charge (R10 + R12 + R14 + R16 + R18) 63 is output by horizontal transfer. Then, as shown in FIG.
40 stages of vertical transfer is performed to transfer the signal charge (G5) to the horizontal transfer path. Then, as shown in FIG. 40H, 8 stages of vertical transfer are continuously performed before horizontal transfer is performed. Done,
An odd-numbered line is added on the horizontal transfer path, and a 5-pixel mixed charge that is a 5-pixel added signal charge as the second added charge
(G5 + G7 + G9 + G11 + G13) 64 is generated.

Then, as shown in FIG. 40 (I), after this signal charge is output by horizontal transfer, 1-stage vertical transfer, horizontal transfer, 9-stage vertical transfer, horizontal transfer ... The operation is repeated to read the image signal to the outside. In this way, after all the pixels are partially added to the vertical transfer path 61 and read out, the vertical transfer path 61 is repeatedly transferred in one stage and nine stages, and as a result, 5 All pixel signals can be read at a double frame rate.

Incidentally, also in the fourth embodiment,
Similar to the first embodiment, with respect to the addition signal which is the 5-pixel mixed charge, the positional relationship between the even-numbered line and the odd-numbered line of the signal charge is reversed. Then, such a phenomenon is caused by a component outside the CCD 2 arranged in the latter stage of the CCD 2 shown in this embodiment and in charge of image processing.
For example, a line buffer is provided as a processing device capable of recording image data for one line, the line signal output first is temporarily held, the next line signal is passed first, and the even line and odd line signals are transmitted. Can be compensated by performing a process of replacing

Next, the configuration using the interlaced complementary color line sequence, which is the fifth and sixth embodiments shown in FIGS. 41 to 47, will be outlined.

That is, the fifth shown in FIGS. 41 to 47.
And a specific color difference line sequential method (complementary color method) using filters of Ye (yellow), Mg (magenta), Cy (cyan), and G (green) as in the sixth embodiment. The present invention can also be applied to a color single plate having a color filter array on the premise of intentional color mixing (filter pair formation), a multi-pixel interline CCD compatible with moving and still images, and thinning. In this multi-pixel interline CCD, one filter pair is first formed on the vertical transfer path, and then vertical transfer is performed while the charge read voltage is applied to a specific charge read electrode, whereby a line of a plurality of same color filter pairs is formed. Then, the color filter pair of the remaining lines is read out and formed on the vertical transfer path while avoiding color mixing with the previous filter pair, and the charge read voltage is applied to the specific charge read electrode again. By performing vertical transfer, line addition is performed for multiple same color filter pairs, and as a result,
All pixels are read out by line addition of multiple filter pairs of the same color, and the moving image is remarkably improved, such as frame rate improvement, vertical spatial frequency reproducibility improvement, and sensitivity improvement, without interfering with the intended later image processing. The image quality can be improved.

That is, the above operation is applied to a color single plate of a color filter array capable of easily generating a color difference signal by line mixing, a moving image still image combined / thinning-compatible multi-pixel interline / interlaced scan CCD, Without affecting the subsequent image processing,
All pixels can be read out by adding a plurality of same color filter pairs.

Next, FIG. 41 shows the fifth embodiment of the present invention.
It will be described with reference to FIGS. The configuration of the fifth embodiment is similar to that of the first embodiment, and the configuration diagram is the same as that of FIG. 1. However, in the present embodiment, as shown in the internal structure of FIG. The present invention is applied to a so-called color difference line sequential method (complementary color method) thinning compatible interline interlaced scan CCD.

That is, in this fifth embodiment, C
The CD is a color interline type interlaced scan CCD. The CCD 2 is characterized by both a still image and a moving image, and has a significantly larger number of pixels than a CCD dedicated for moving images. Therefore, when shooting a still image, all pixels are read individually by using a mechanical shutter together. By mixing pixels during shooting, all pixels are
It can be read at twice the frame rate. In addition, this color filter array can facilitate subsequent image processing by intentionally mixing filter pixels of different colors during a moving image. That is, by adding the vertically adjacent pixels together, Ye + Mg, Y
Four kinds of filter pair signals of e + G, Cy + G and Cy + Mg can be taken out. Then, (Ye + Mg) + (Cy + G) = 2R + 3G + 2B≈luminance signal Y1 (Ye + G) + (Cy + Mg) = 2R + 3G + 2B≈luminance signal Y2 (Cy + G) − (Ye + Mg) = G−2R ≈color difference signal Cr (Ye + G) − (Cy + Mg) = G−2B ≈color difference signal Cb As shown in FIG. , It is very easy to generate an approximate signal of the color difference signal. Therefore, such a color filter array is generally used as a color CCD for movies.
It has become popular as a filter array.

The CCD has a photodiode 15 as a photoelectric conversion means, as shown in the internal structure of FIG.
And the first CC connected to these photodiodes 15.
A vertical transfer path 16 which is D and a vertical transfer path gate signal wiring 18 connected to each of the vertical transfer paths 16 are provided. Further, in the figure, an arrow 19 indicates a forward direction which is a vertical transfer direction to a horizontal transfer path direction which is a second CCD (not shown).

Further, the photodiodes 15 respectively form pixels and are two-dimensionally arranged in a predetermined pattern. In the present embodiment, the color filters are arranged in the color difference line sequential system (complementary color system) as described above. Then, the combination of the color filters in a predetermined column becomes Ye, Mg, Ye, G ... And M
g and G are located on even-numbered horizontal lines. The combination of the color filters in the columns adjacent to this column is Cy, Mg, Cy, G ... And Mg and G are located on even-numbered horizontal lines.

Then, the signal charges accumulated in the photodiodes 15 are applied to the vertical transfer path 16 side by applying a charge read pulse, which is a charge read voltage having a positive potential, to the gate electrodes of the vertical transfer paths 16 adjacent to each other. Read out. As shown in FIG. 41, the combination of the vertical transfer path gate electrodes which accompanies such charge reading operation of the CCD is V1A,
There are 6 systems of V1B, V1C, V3A, V3B, V3C, and gate electrodes V2 and V4 dedicated to vertical transfer without charge read operation are added to these 6 system electrodes, and there are a total of 8 systems of vertical transfer path gate electrodes. Then, each is connected to the vertical transfer path gate signal wiring 18.

Although the CCD of the above-mentioned embodiment shows the case of 4-line addition (addition of two pairs of the same color filter pair) as an example, actually, the electrodes corresponding to V1A and V3A are considered in the color filter. However, CCDs with various line addition numbers can be realized depending on how many lines are arranged. Furthermore, no matter how the number of lines added increases, the number of vertical transfer gate electrodes does not increase.

In this embodiment, the signal read operation is the same as that in the first embodiment when the still image is photographed.
In the (all pixel individual read mode), one screen is divided into two fields of even lines and odd lines, and all pixels are read independently. On the other hand, at the time of shooting a moving image (moving image mode), the above filter pairs are added together while avoiding color mixture with other filter pairs, and all pixel signals are read out at a high speed at a quadruple frame rate.

The operation at the time of capturing a still image is to read out all pixels independently as in each of the above-mentioned embodiments, and the description thereof will be omitted.

A mode of reading out all the pixels by adding two pairs of filters of the same color when shooting a moving image will be described below with reference to FIGS. 42 to 44. That is, FIGS. 42 and 43 describe the state of charge reading and vertical transfer in the leftmost column in FIG. 41, but in the following description, the same applies to all other columns including adjacent columns. It is assumed that the operation is occurring. That is, charge reading and vertical transfer are performed in horizontal line units. In addition, FIG.
The voltage waveforms of the vertical transfer path gate signals denoted by V1A to V4 shown in FIG. 4 and the voltage waveforms of the vertical transfer path gate signals denoted by V1A to V4 shown in FIG. 43 are the same. On the other hand, FIG. 42 shows the first half part and FIG. 43 shows the second half part of the waveform showing the potential state of the vertical transfer path with A to U shown in the direction orthogonal to this voltage waveform.

First, as an initial state, the charge transfer pulse 71 is added only to V3C as shown in FIG. 42B from the state where each vertical transfer path gate signal and potential state are shown in FIG. 42A, and Mg ( All the signal charges of the line where (magenta) exists are read out to the vertical transfer path. Next, FIG.
42C, a predetermined voltage is applied to V1A to V4 with the application of the V3C charge read pulse stopped, and as shown in C to E in FIG. 1 /
Vertical transfer for two stages, that is, reverse transfer. Then, FIG.
As shown in F of 2, a charge read pulse is applied to V1A and V1B. Then, the signal charges of Mg and Ye (yellow) are added together to form the filter pair signal Mg + Ye. Next, as shown in G of FIG. 42, after the application of the charge read pulse of V1B is stopped while the charge read pulse is being applied to V1A, as shown in H to J of FIG. Vertical transfer, that is, reverse transfer is performed in the direction. Then,
Since the potential well is deep under the electrode of V1A that exists every eight lines, two filter pair signals Mg + Ye of the same color are mixed in the charge holding unit under V1A. That is, in this charge holding portion, the pixel signal signal charges for four pixels are added. After that, as shown in K of FIG. 42 and K of FIG. 43, when the application of the charge read pulse of V1A is stopped, two filter pair signals of the same color are added and held under the electrode of V1A. become. Further, from this state, as shown by L in FIG. 43, a charge read pulse is applied to V1C to read out the signal charge of Ye above G (green). Next, as shown in M to O of FIG. 43, application of the charge read pulse of V1C is stopped, and after 1/2 stage of vertical transfer in the horizontal transfer path direction, that is, in the positive direction,
As shown in P of FIG. 43, a charge read pulse is applied to V3A and V3B. Then, the signal charges of G and Ye are added together to form the filter pair signal G + Ye. further,
In this state, as shown in Q of FIG. 43, after the application of the charge read pulse of V3B is stopped while the charge read pulse is being applied to V3A, horizontal transfer is further performed as shown in R to T of FIG. Vertical transfer for two steps is performed in the road direction, that is, the forward direction. Then, since the potential well is deep under the V3A electrode that exists every eight lines, two pairs of filter pair signals G + Ye of the same color are mixed in the charge holding section under V3A. That is, in this charge holding portion, the pixel signal charges for four pixels are added. After that, as shown in U of FIG. 43, when the application of the charge read pulse of V3A is stopped, two filter pair signals of the same color are added and held under the electrode of V3A.

After this, as shown in the situation of the pixels read out in FIG. 44, first, the signal charge (G0 + Ye) of the vertical transfer path
1) + (G4 + Ye5) is transferred to the horizontal transfer path and horizontally transferred.
After that, the signal charges (Mg2 + Ye3) +
(Mg6 + Ye7) is read to the horizontal transfer path and horizontally transferred. Thereafter, similarly, the vertical transfer for one stage, the horizontal transfer, the vertical transfer for three stages, the horizontal transfer, ... Are repeated, and the all-pixel charge signals line-mixed at a frame rate four times that of the still image can be read out. .

In this embodiment, the pixel mixture is realized by performing the reverse transfer on the vertical transfer path. However, in the sixth embodiment shown below, as in the above-mentioned respective embodiments. , Pixel mixing is possible only by the transfer in the forward direction on the vertical transfer path without the reverse transfer, and in this case, the mixing of the same color filter pair signals can be realized, that is, all the pixel mixing can be performed only by the vertical transfer in the positive direction. C that realizes and controls image processing etc.
Line order can be compensated by components outside the CD. Further, also in this embodiment, similarly to the second embodiment, the pixel mixture on the odd line side can be performed on the horizontal transfer path.

Next, FIG. 45 shows a sixth embodiment of the present invention.
47 to FIG. 47.

Then, the CCD 2 of the sixth embodiment
The basic operation including the internal structure of the CCD and the driving of the CCD 2 is shown in FIG.
The operation is the same as that of the fifth embodiment shown in FIG. 1, and the description of the operation in the all-pixel individual read mode is omitted. In addition, in this embodiment, in the vertical transfer path, it is sufficient to transfer the signal charges only in the positive direction, which is the horizontal transfer path direction, and it is not necessary to perform the reverse transfer. In addition, the versatility can be improved, and the time required for the read operation can be slightly shortened as compared with the fifth embodiment by incorporating the addition in the horizontal transfer path. Further, in the sixth embodiment, the combination of filter pair addition is changed from that of the fifth embodiment.

The mode of reading out all the pixels by adding two pairs of filters of the same color when shooting a moving image will be described below with reference to FIGS. 45 to 47. That is, FIGS. 45 and 46 describe the state of charge reading and vertical transfer in the leftmost column in FIG. 41, but in the following description, the same applies to all other columns including adjacent columns. It is assumed that the operation is occurring. That is, charge reading and vertical transfer are performed in horizontal line units. Also, FIG.
The voltage waveforms of the vertical transfer path gate signals denoted by V1A to V4 shown in FIG. 4 and the voltage waveforms of the vertical transfer path gate signals denoted by V1A to V4 shown in FIG. 46 are the same. On the other hand, FIG. 45 shows the first half portion and FIG. 46 shows the latter half portion of the waveforms showing the potential status of the vertical transfer paths denoted by A to V shown in the direction orthogonal to this voltage waveform.

First, as the initial state, the vertical transfer path gate signal and the potential state are changed from the state shown in A of FIG. 45 to the charge read pulse 81 only to V1C as shown in B of FIG. The signal charge of 1/2, that is, Ye above G is read out to the vertical transfer path. Next, FIG.
As shown by C in FIG. 5, a predetermined voltage is applied to V1A to V4 in a state in which the application of the charge read pulse of V1C is stopped, and FIG.
As shown in C to D, the vertical transfer is performed by 1/2 stage in the horizontal transfer path direction. Next, as shown in E of FIG. 45, V3A, V3
Add charge read pulse to B. Then, the signal charges of Ye and G are added together to form the filter pair signal G + Ye. Next, as shown in F of FIG. 45, after the application of the charge read pulse of V3B is stopped while the charge read pulse is being applied to V3A, as shown in G to I of FIG. Transfer. Then, since the potential well is deep under the electrode of V3A which exists every 8 lines, two filter pair signals G + Ye of the same color have V
It is mixed in the charge holding part under 3A. That is, in this charge holding portion, the pixel signal charges for four pixels are added. Thereafter, as shown in J of FIG. 45 and J of FIG. 46, when the application of the charge read pulse of V3A is stopped, V3A
Under the electrode of, the two filter pair signals of the same color are added and held. Further, from this state, as shown by K to P in FIG. 46, vertical transfer for 1.5 steps is performed in the horizontal transfer path direction, that is, the positive direction, and the filter pair signal is temporarily saved below the V1C electrode. From this state, as shown in Q in FIG. 46, a charge read pulse is applied to V1A and V1B, and Y
A signal charge of ½ of e, that is, Ye above Mg is read out to the vertical transfer path. Next, as indicated by R in FIG. 46, the application of the charge read pulses of V1A and V1B is stopped. Next, as shown in S to T of FIG. 46, vertical transfer for ½ stage is performed. Then, as shown in U of FIG. 46, V3
Apply a charge read pulse to C. Then, the signal charge of Mg is added to Ye, and the filter pair signal Mg + Ye is added.
Is formed. Then, as shown by V in FIG. 46, V3C
When the application of the charge read pulse is stopped, Mg + Ye is held under the V3C electrode.

After that, as shown in the state of the pixel read out in FIG. 47, first, after horizontally transferring and outputting the signal charges (G0 + Ye1) + (G4 + Ye5) already on the horizontal transfer path,
The signal charge (Mg2 + Ye3) is output by vertical transfer and horizontal transfer. After that, one-stage vertical transfer, horizontal transfer, three-stage vertical transfer, and horizontal transfer are repeated, and all pixel charge signals line-mixed at a frame rate four times that of a still image can be read out.

Incidentally, also in the sixth embodiment,
Similar to the first embodiment, with respect to the addition signal which is the 5-pixel mixed charge, the positional relationship between the even-numbered line and the odd-numbered line of the signal charge is reversed. Then, such a phenomenon is caused by a component outside the CCD 2 arranged in the latter stage of the CCD 2 shown in this embodiment and in charge of image processing.
For example, a line buffer is provided as a processing device capable of recording image data for one line, the line signal output first is temporarily held, the next line signal is passed first, and the even line and odd line signals are transmitted. Can be compensated by performing a process of replacing

In the above fifth and sixth embodiments, the interlaced CCD has been described as an example. However, the correlation between the first and second embodiments and the third embodiment, and In consideration of the operation of the embodiment, it is obvious that the present invention can be easily applied to the progressive CCD. By the way, in case of progressive CCD,
The vertical transfer path gate electrode (readout electrode) can be realized by four systems as in the third embodiment.

As described above, in the case of the line-mixed filter array, which is widely used in movie cameras and the like, six read-out electrodes are required, but the effect is the same as in the above-mentioned embodiments. Similarly, the number of lines to be added can be dealt with, the number of vertical transfer electrodes does not change, and an increase in cost can be suppressed.

In each of the above-described embodiments, the so-called second addition using the horizontal transfer path is configured such that vertical transfer is only forward transfer, or vertical transfer includes not only forward transfer but also reverse transfer. It can be combined with any of the configurations.

Further, also in the configuration in which the vertical transfer is only the normal transfer, it is possible to complete the addition using the vertical transfer path without using the addition using the horizontal transfer path. In the interlaced complementary color line sequential CCD, the electrode wiring different from the configuration of the sixth embodiment is used for the configuration in which the addition is completed by the vertical transfer of the forward transfer.

Further, in each of the above embodiments, for example, 5
Although the signal charge of each pixel is added to obtain the added charge, the present invention is not limited to this configuration, and if the signal charges of two or more pixels that are not continuous in the vertical direction are added, the frame rate and the image quality can be improved. It is possible to exert an effect.

Further, in the above embodiment, the signal charges of all the pixels are read and used. However, a part of the signal charges out of the effective pixels are not read, and the read signal charges are not used. it can.

[0235]

According to the image pickup device of the first aspect of the present invention, when a moving image is taken, the thinning-out reading mode and the addition reading are performed manually or automatically by the control of the control means in accordance with the taking situation and the taking object. By switching between the modes, the quality of the image can be easily improved. Further, since switching between the thinning readout mode and the addition readout mode can be performed by controlling the image pickup element, the configuration does not become complicated, and the manufacturing cost can be reduced.

According to the image pickup device of the second aspect, in addition to the effect of the first aspect, a commonly used CCD solid-state image pickup element can be used to reduce the manufacturing cost, and
Image quality can be improved and processing speed can be improved.

According to the image pickup device of the third aspect, at the time of preliminary photographing, the thinning-out reading mode, the addition reading mode, and the mixed-color addition reading mode are automatically set by the control of the control means in accordance with the shooting situation and the shooting object. By switching between, the data for main shooting is effectively measured, and the quality of the image during main shooting is improved.

According to the image pickup device of claim 4, in addition to the effect of any one of claims 1 to 3, the control means switches between the addition read mode and the thinning read mode in accordance with the brightness of the photographing condition. To drive the image sensor,
When it is dark, it is possible to switch to the addition reading mode and shoot a higher quality image than the thinning reading mode, or to perform high-speed processing.

According to the image pickup device of the fifth aspect, in addition to the effect of any one of the first to fourth aspects, the control means determines the possibility of occurrence of the moire, and if the moire is likely to occur. In order to drive the image sensor by switching to the addition read mode and in the thinning read mode in other cases,
By switching the thinning-out reading mode to the addition reading mode according to the shooting target, it is possible to suppress the occurrence of moire and shoot a high-quality image.

According to the image pickup device of claim 6, in addition to the effect of any one of claims 1 to 5, the control means determines the possibility of occurrence of smear, and when there is the possibility of occurrence of smear. In order to drive the image sensor by switching to the thinning readout mode, and in the addition readout mode in other cases,
By switching the addition read mode to the thinning read mode according to the shooting target, it is possible to suppress deterioration of image quality due to smear and shoot a high-quality image.

According to the image pickup device described in claim 7, in addition to the effect according to any one of claims 1 to 6, when the image pickup device is driven in the addition read mode under the control of the control means,
Since the saturation suppressing unit that suppresses the saturation of the signal inside the image sensor is provided, the saturation of the signal inside the image sensor can be suppressed and the image quality can be improved in the addition read mode.
Further, it is not necessary to use a dedicated image pickup device having a large capacity, and an increase in manufacturing cost can be suppressed.

According to the image pickup apparatus described in claim 8, in addition to the effect described in any one of claims 1 to 7, by using the all-pixel individual reading mode, a high-definition image such as a still image can be taken and the thinning-out reading can be performed. By using the mode or the addition reading mode, preliminary measurement requiring a high frame rate or shooting of a moving image can be performed.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an image pickup apparatus of the present invention.

FIG. 2 is a partial explanatory view showing an internal structure of a CCD of the image pickup device of the same.

FIG. 3 is a flowchart showing the operation of the first embodiment of the image pickup apparatus of the present invention.

FIG. 4 is a time chart showing the operation of the second embodiment of the image pickup apparatus of the present invention.

FIG. 5 is a flowchart showing an operation of the second embodiment of the imaging device of the above.

FIG. 6 is a time chart showing the operation of the third embodiment of the image pickup apparatus of the present invention.

FIG. 7 is a flowchart showing an operation of the third embodiment of the imaging device of the above.

FIG. 8 is a flowchart showing an operation of the fourth embodiment of the image pickup apparatus of the present invention.

FIG. 9 is a flowchart showing an operation of the fifth embodiment of the image pickup apparatus of the present invention.

FIG. 10 is a configuration diagram showing a seventh embodiment of an imaging device of the present invention.

FIG. 11 is a flowchart showing an operation of the image pickup apparatus according to the seventh embodiment of the same.

FIG. 12 is an explanatory diagram showing a CCD all-pixels individual reading mode of the image pickup apparatus of the present invention.

FIG. 13 is an explanatory diagram showing an all-pixel individual reading mode of the CCD of the imaging device.

FIG. 14 is an explanatory diagram showing a CCD thinning-out reading mode of the image pickup apparatus of the present invention.

FIG. 15 is an explanatory diagram showing a CCD addition read mode of the image pickup apparatus of the present invention.

FIG. 16 is an explanatory diagram showing a CCD addition read mode of the image pickup apparatus of the same.

FIG. 17 is an explanatory diagram showing a CCD addition read mode of the image pickup apparatus of the same.

FIG. 18 is an explanatory diagram following FIG. 17 of the above.

FIG. 19 is an explanatory diagram following FIG. 18 of the above.

FIG. 20 is an explanatory diagram showing an outline of an all-pixels individual reading mode of the CCD of the imaging device.

FIG. 21 is an explanatory diagram showing an outline of a thinning-out readout mode of a CCD of the imaging device.

FIG. 22 is an explanatory diagram showing the outline of the addition reading mode of the CCD of the imaging device.

FIG. 23 is a schematic explanatory diagram of line read out addition showing the second embodiment of the CCD addition read out mode of the image pickup device of the present invention.

FIG. 24 is an explanatory diagram showing a CCD addition read mode of the same imaging device.

25 is an explanatory diagram following FIG. 24 of the above.

FIG. 26 is an explanatory diagram showing a CCD addition read mode of the image pickup apparatus of the same.

FIG. 27 is an explanatory diagram that follows FIG. 26 above.

28 is an explanatory diagram continued from FIG. 27 of the same.

FIG. 29 is an explanatory diagram of part of the internal structure of the CCD showing the third embodiment of the CCD of the image pickup device of the present invention.

FIG. 30 is an explanatory diagram showing an all-pixel individual reading mode of the same as above.

FIG. 31 is an explanatory diagram showing a CCD addition read mode of the image pickup apparatus of the same.

32 is an explanatory diagram following FIG. 31 of the above.

FIG. 33 is an explanatory diagram showing a CCD addition read mode of the same imaging device.

FIG. 34 is an explanatory diagram following FIG. 33 above.

FIG. 35 is an explanatory diagram that follows FIG. 34 above.

FIG. 36 is an explanatory diagram showing an addition read mode showing a fourth embodiment of the CCD of the image pickup device of the present invention.

FIG. 37 is an explanatory diagram that follows FIG. 36 above.

FIG. 38 is an explanatory diagram showing a CCD addition read mode of the image pickup apparatus of the same.

FIG. 39 is an explanatory diagram following FIG. 38 of the above.

FIG. 40 is an explanatory diagram following FIG. 39 above.

FIG. 41 is an explanatory diagram of a part of the internal structure of the CCD showing the fifth embodiment of the CCD of the image pickup device of the present invention.

FIG. 42 is an explanatory diagram showing a CCD addition read mode of the image pickup device of the above.

FIG. 43 is an explanatory diagram following FIG. 42 above.

FIG. 44 is an explanatory diagram showing an outline of line read addition in a CCD addition read mode of the same imaging device.

FIG. 45 is an explanatory diagram showing a CCD addition read mode showing a sixth embodiment of a CCD of an image pickup device of the present invention.

FIG. 46 is an explanatory view following FIG. 37 above.

FIG. 47 is an explanatory diagram showing an outline of line read addition in a CCD addition read mode of the image pickup apparatus of the same.

[Explanation of symbols]

1 Imaging device 2 CCD as an image sensor 4. Analog processing circuit which constitutes image processing means 13 Substrate bias voltage switching circuit as saturation suppression means 14 CPU constituting control means 15 Photodiode as photoelectric conversion means 33 Signal charge

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5C022 AA13 AB17 AC01 AC42 AC69                 5C024 BX01 CX13 CX37 CX56 CY11                       CY17 GY04 GZ27 HX02 HX50                       JX14                 5C065 AA01 AA03 BB13 BB24 DD02                       EE10 GG21

Claims (8)

[Claims] 1. An image pickup device comprising a plurality of pixels arranged in a predetermined pattern and provided with photoelectric conversion means, control means for controlling the image pickup device, and an image to which signal charges output from the image pickup device are inputted. A thinning-out read mode in which a signal charge of a part of pixels of the image sensor is read out and output to the image processing unit when a moving image is captured; and a signal charge of a pixel of the image sensor. And an addition reading mode in which the signal charges of a plurality of pixels are added and output to the image processing unit are switched. 2. The image pickup device is a CCD solid-state image pickup device having a plurality of pixels in which a plurality of colors are arranged in a predetermined pattern, and the addition read mode adds signal charges of a plurality of pixels of the same color. The imaging device according to claim 1, wherein 3. An image pickup device comprising a plurality of pixels in which a plurality of colors are arranged in a predetermined pattern by providing photoelectric conversion means, control means for controlling the image pickup device, and signal charges output from the image pickup device. And an image processing unit to be input, wherein the control unit reads out signal charges of some pixels of the image sensor and outputs the signal charges to the image processing unit during preliminary shooting for measuring data for main shooting. Mode, an addition read mode in which the signal charges of the pixels of the image sensor are read and the signal charges of a plurality of pixels of the same color are added and then output to the image processing unit, and the signal charges of the pixels of the image sensor are read in different colors. The image pickup apparatus is characterized in that the signal charge of a plurality of pixels is added and then the mixed color addition read mode for outputting to the image processing means is switched. 4. The control means adjusts according to the brightness of the photographing situation.
4. The image pickup apparatus according to claim 1, wherein the image pickup device is driven by switching between the addition read mode and the thinning read mode. 5. The control means determines the possibility of occurrence of moire, and switches to the addition reading mode when there is the possibility of occurrence of moire, and switches to the thinning-out reading mode in other cases to drive the image sensor. The imaging device according to any one of claims 1 to 4, characterized in that. 6. The control means determines the possibility of occurrence of smear, and switches to the thinning-out read mode when there is a possibility of occurrence of smear, and switches to the addition read mode in other cases to drive the image sensor. The image pickup apparatus according to claim 1, wherein the image pickup apparatus is an image pickup apparatus. 7. The saturation suppressing means, which is controlled by the control means, suppresses saturation of a signal inside the image pickup device when the image pickup device is driven in the addition read mode. 6. The image pickup device according to any one of 6 above. 8. The control means reads out a signal charge of a part of pixels of the image pickup device and outputs the signal charge to the image processing means, and a signal charge of a pixel of the image pickup device and a signal charge of a plurality of pixels. A switching control is performed between an addition read mode in which the signal is added and then output to the image processing unit, and an all-pixel individual read mode in which signal charges of substantially all pixels of the image sensor are independently read and used. Item 9. An image pickup device according to any one of items 1 to 7.