JPH01220986A - Ccd image pickup device - Google Patents

Abstract

PURPOSE:To use an image pickup means in common by using an electric charge transferred from a 1st horizontal transfer means in case of the sequential scanning system as a video signal and using the electric charge from the 1st and 2nd horizontal transfer means as a video signal in case of the interlace scanning system. CONSTITUTION:In case of the sequential scanning system, a switch circuit 13 is switched to the position A, a horizontal drive section 12, based on a clock supplied from a clock generator 14, drives 1st and 2nd line transfer sections 19, 20, only the signal charge from the 1st line transfer section 19 is outputted from the 1st output terminal 23 and the signal charge sent from a vertical transfer section 18 is sent sequentially to the 1st line transfer section 19 and outputted as a video signal. In case of the interlace scanning system, the switch circuit 13 is switched to the position B, the signal charge from the 1st and 2nd line transfer sections 19, 20 is superimposed by an adder 15 and 1st and 2nd field video signals are outputted alternately from a 2nd output terminal 24. Thus, the image pickup means is used in common.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a CCD imaging device used, for example, in an electronic camera.

(Conventional technology) N, which has been adopted as a broadcasting method in Japan, the United States, etc.
The TSC method uses an increment scanning method.

That is, in the first field, the first scan is performed with 262.5 coarse scanning lines, and in the next second field, the second scan is performed with 282.5 scanning lines to fill in the space between them. By doing this, one frame of image is constructed.

On the other hand, in technical fields that require improved image quality, there is a tendency to adopt a progressive scanning method (non-incremental scanning method) in which one frame is scanned by 525 scanning lines at a time.

By the way, when such a progressive scanning method is adopted for a general television receiver, flickering occurs extremely prominently, so the scanning speed is usually doubled and the horizontal scanning frequency is increased to 31.
．． Attempts have been made to increase the frequency to 5KHz and one frame to 80Hz. However, in this case, although the occurrence of flicker can be prevented, there is a problem in that a dedicated receiver is required.

On the other hand, when obtaining still images, such as with an electronic camera, the progressive scanning method is often more convenient because it is sufficient to obtain only one image. This is because, for example, when recording an obtained image using a printer, one complete image can be obtained by one scan from the edge of the screen.

However, when reproducing still images captured by this electronic camera on a color receiver, it is desirable to use an interlaced scanning method because if the progressive scanning method is used, flicker will be noticeable unless double-speed scanning is performed as described above.

Under these circumstances, in recent years, there has been a strong desire to develop an apparatus that can switch between the incremental scanning method and the progressive scanning method. However, as an imaging means, C.
When a solid-state imaging device such as a CD is used, it is difficult to use the same imaging means for both the interlaced scanning method and the progressive scanning method.

This means, for example, that 500 pixels of photodiodes are arranged vertically as a photoelectric conversion unit, or that a vertical transfer CCD is used.
This is because the vertical transfer CCD has the ability to transfer signals for only 250 pixels, and even if a vertical transfer CCD has the ability to transfer signals for 500 pixels, in the case of an interlaced scanning method, the COD is driven at double speed scanning, and the output circuit This is because a complicated electronic circuit is required to perform scan conversion by providing means for delaying the signal by one frame, which is impractical. Also, if the CCD is operated at double speed in this way, for example, 8
When using a CCD with 00,000 pixels, the horizontal transfer CCD must be operated at a frequency of 28.6 MIIz,
There are also drawbacks such as poor transfer efficiency, which causes resolution deterioration. Further, when a single-plate color solid-state image sensor is used as an imaging means, there are many restrictions due to the arrangement of color filters, and there are also drawbacks such as the inability to use a checker arrangement with the highest resolution.

(Problems to be Solved by the Invention) As described above, in the conventional CCD imaging device, there are various problems in using the same imaging means for both the interlaced scanning method and the progressive scanning method.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a CCD imaging device that has a simple configuration and can be used for both the interlaced scanning method and the progressive scanning method using the same imaging means.

[Structure of the Invention] (Means for Solving the Problems) The present invention includes a photoelectric conversion means having a plurality of photoelectric conversion elements in the vertical and horizontal directions, and a vertical transfer method for vertically transferring charges from the photoelectric conversion elements provided for each line of the photoelectric conversion elements. a first horizontal transfer means that horizontally transfers charges transferred from each line of the vertical transfer means; and a first horizontal transfer means that receives charges corresponding to each line from the first horizontal transfer means and transfers the charges horizontally a second horizontal transfer means for superimposing charges transferred from the first and second horizontal transfer means; and a superposition means for superimposing charges transferred from the first and second horizontal transfer means; and control means for controlling charge transfer.

(Function) In the present invention, in the case of a progressive scanning method, the charge transferred from the first horizontal transfer means is used as a video signal, and in the case of an interlaced scanning method, the charge transferred from the first and second horizontal transfer means superimposed by the superimposing means is used as a video signal. The charge from the transfer means may be used as a video signal.

(Example) Hereinafter, details of an example of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing the configuration of a CCD imaging device according to an embodiment of the present invention, in which an imaging section 11, a horizontal drive section 12
, switch circuit 13, clock generator 14, adder 15
and a clock source 16.

As shown in FIG. 2, the imaging section 11 includes a photosensitive section 17 consisting of 500 vertically x 400 horizontal photodiodes;
5 arranged adjacent to each vertical line of this photosensitive section 17.
00 stages, the first and second line transfer sections 19.20 provided adjacent to these, and the first and second line transfer sections 19.20. It is composed of a gate 21 inserted therein. Note that a pulse for operating the vertical transfer section 18 is inputted from the terminal 22 .

The horizontal drive section 12 horizontally drives the first and second line transfer sections 20 based on the clock supplied from the clock generator 14 .

The switch circuit 13 performs various switching based on selection pulses supplied from the clock generator 14.

The clock generator 14 inputs the clock generated by the clock source 16, and generates pulses for opening and closing the gate 21, 28MH2 and 14MH for supplying to the horizontal drive section 12.
2, the switch circuit 13 outputs a selection pulse for switching.

The adder 15 superimposes the signals output from the first and second line transfer sections 19 and 20.

Next, the operation according to the progressive scanning method will be explained based on FIG.

In addition, in this embodiment, in the case of the sequential scanning method, the third
As shown in figure (a), one frame is 1130 seconds long and has 52 frames.
It is composed of five sequential scanning signals.

First, as shown in FIG. 3(b), when the sweep pulse Ps is inputted to the terminal 22, unnecessary waste that has been accumulated up to that time from each photodiode of the photosensitive section 17 to the vertical transfer section 18 is inputted to the terminal 22. Charge is transferred and a sweep operation is performed at high speed.

After this t seconds, the field shift pulse Pi is applied to the terminal 22.
is applied, and the signal charges that have been photoelectrically converted and accumulated in the photosensitive section 17 during this t seconds are transferred to the vertical transfer section 18.

That is, as shown in FIG. 3(C), this time t is
This is the shutter time.

Here, in the case of the progressive scanning method, the switch circuit 13 is switched to the A side. Therefore, in the horizontal driving section 12, the first and second line transfer sections 19 and 20 are driven based on the 14 MHz clock supplied from the clock generator 14, and the gate 21 is driven based on the 14 MHz clock supplied from the clock generator 14.
The L° pulse causes the closed state, that is, the first line transfer section 1
9 to the second line transfer section 20, and only the signal charges from the first line transfer section 19 are output from the first output terminal 23.

Then, the signal charges sent out from the vertical transfer section 18 are sequentially sent to the first line transfer section 19, and the signal charges are sent to the first output terminal 23.
As shown in FIG. 3(d), the signal is output as a video signal.

Next, the operation according to the increment scanning method will be explained based on FIG. 4.

In this embodiment, in the case of the interlaced scanning method, as shown in FIG.
Consists of fields.

First, as shown in FIG. 4(b), when the sweeping pulse Ps is inputted to the terminal 22, unnecessary waste that has been accumulated up to that time from each photodiode of the photosensitive section 17 to the vertical transfer section 18 is inputted to the terminal 22. Charge is transferred and a sweep operation is performed at high speed.

After this t seconds, the field shift pulse Pi is applied to the terminal 22.
is applied, and the signal charges that have been photoelectrically converted and accumulated in the photosensitive section 17 during this t seconds are transferred to the vertical transfer section 18.

That is, as shown in FIG. 4(C), this time t is
This is the shutter time.

Here, in the case of interlace scanning method, switch circuit 1
3 is switched to the B side. Therefore, the horizontal drive section 12 operates the first and second line transfer sections 19 and 20 based on the 28 MHz clock supplied from the clock generator 14.
is driven, and the gate 21 is brought into an open state by the "H° pulse supplied from the clock generator 14, that is, a state in which signal charges are supplied from the first line transfer section 19 to the second line transfer section 20, and second line transfer section 1
The signal charges from 9.20 are superimposed by the adder 15 and are output from the second output terminal 24.

The signal charges sent from the vertical transfer section 18 are sequentially sent to the first and second line transfer sections 19.20, and the signal charges from the first and second line transfer sections 19.20 are sent to the adder 15. from the second output terminal 24 to the fourth
As shown in Figure (d), the video signal of the first field and the video signal of the second field, which correspond to 250 scanning lines, are output alternately.

That is, if you type the pixel numbers 1, 2, 3...500 from the one closest to the first and second line transfer units 19, 20,
As shown in Figure 5, in the first field, 1+2.3
+4.5+6...499+500 is added, and the second
In the field, 2+3.4+5.6+7...498
This is because the addition is +499.

As described above, in this embodiment, a CCD is used as an imaging means.
Even though a solid-state image sensor such as the above is used, it is possible to switch between the incremental scanning method and the progressive scanning method.

In this embodiment, if necessary, the signal from the second output terminal 24 can be added to the field memory and read out as a standard scanning speed signal to be reproduced on a television receiver. .

Next, another embodiment of the present invention will be described based on FIG.

As shown in the figure, in this second embodiment, an accumulation section 2 is provided between the vertical transfer section 18 and the first line transfer section 19 in the imaging section.
5 was inserted.

Then, the signal charge from the vertical transfer section 18 is temporarily accumulated in the accumulation section 25, and the same operation as in the embodiment described above is performed. According to this, the signal charges in the photosensitive section 17 are emptied and the next accumulation operation is started again, so that continuous signals can be obtained using this configuration.

Therefore, in the above-mentioned embodiments, there were missing portions of the signal as shown in FIGS. 3 and 4, but according to the configuration shown in FIG. 6, such missing portions are eliminated and a continuous signal is obtained. There is an effect.

[Effects of the Invention] As explained above, according to the present invention, in the case of a progressive scanning method, the charge transferred from the first horizontal transfer means is used as a video signal, and in the case of an incremental scanning method, the charge transferred from the first and second horizontal transfer means is used as a video signal. Since the charge from the horizontal transfer means can be used as the video signal,
With a simple configuration, the same imaging means can be used for both the incremental scanning method and the progressive scanning method.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a CCD imaging device according to an embodiment of the present invention, FIG. 2 is a diagram showing the configuration of the imaging section of this embodiment, and FIGS. FIG. 6 is a diagram for explaining the operation and shows another embodiment of the present invention. 11... Imaging unit, 12... Horizontal drive unit, 13...
Switch circuit, 14...Clock generator, 15...
Adder, 16... Clock source, 17... Photosensitive section, 1
8... Vertical transfer unit, 19... First line transfer unit,
2o...Second line transfer unit, 21...Gate. Applicant: Toshiba Corporation Patent attorney: Sa-Shun Suyama, OOυ

Claims (1)

[Claims] (1) A photoelectric conversion means having a plurality of photoelectric conversion elements vertically and horizontally, a vertical transfer means provided for each line of photoelectric conversion elements and vertically transferring charges from the photoelectric conversion elements, and transfer from each line of the vertical transfer means a first horizontal transfer means that horizontally transfers the charges to be transferred; and a second horizontal transfer means that receives charges corresponding to each line from the first horizontal transfer means and transfers them horizontally.
a horizontal transfer means, a superimposition means for superimposing charges transferred from the first and second horizontal transfer means, and a superimposition means for superimposing charges transferred from the first and second horizontal transfer means;
and control means for controlling charge transfer from the horizontal transfer means to the second horizontal transfer means.