JPH0336885A - Electronic camera device - Google Patents

Abstract

PURPOSE:To improve the timewise resolution with sharpness by implementing plural number of times of sweepout of undesired charge and readout of signal charge in one field period and extracting the signal charge read for plural number of times in one field period as an output of a solid-state image pickup element. CONSTITUTION:The sweepout of undesired charge and the transfer of the vertical and horizontal direction of the signal charge or the like are controlled for a solid-state image pickup element 11 by using various pulses outputted from a horizontal drive circuit 12 and a vertical drive circuit 13. The extracted video signal is processed by a 1st signal processing circuit 14 and a 2nd signal processing circuit 15 and recorded on a tape by a VTR 16. In this case, the sweepout of undesired charge and readout of signal charge in one field period are implemented for plural number of times while the entire photodetector plane is split from the solid-state image pickup element 11 and the signal charge read from the photodetector plane corresponding to in one field period is extracted as the output of the solid-state image pickup element 11.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention relates to an electronic camera device using a solid-state image sensor, and in particular to an electronic camera device that is capable of photographing multiple frames within one field period. Concerning what has been done.

(Prior Art) As is well known, in imaging devices such as still cameras and video cameras, a CCD (charge coupled device) is used to convert an optical image of a photographed subject into an electrical signal. Solid-state image sensing devices such as these have been used. This solid-state image sensor includes a photoelectric conversion unit having a plurality of photoelectric conversion elements arranged planarly in the horizontal and vertical directions, and is installed corresponding to each photoelectric conversion element of this photoelectric conversion unit, and each photoelectric conversion element A vertical transfer section has a plurality of vertical transfer stages capable of vertical charge transfer, and each vertical transfer stage of this vertical transfer section supplies signal charges transferred vertically. The horizontal transfer stage includes a horizontal transfer stage, and an output amplifier that amplifies and outputs the signal charges transferred to the horizontal transfer stage.

Conventionally, within one field period, unnecessary charges in the vertical transfer section are first swept away at high speed, and then the signal charges accumulated in the photoelectric conversion section are transferred to the vertical transfer section by a field shift pulse, and then the line shift pulse The signal charges transferred to the vertical transfer section are transferred line by line to the horizontal transfer stage and output. Therefore, the photoelectric conversion unit is exposed to light for a period from when a field shift pulse is generated until the next field shift pulse is generated, that is, for one field period (1760 seconds) to accumulate charges. When a fast-moving subject is photographed, the image will be blurred due to the integration of signal charges due to incident light over 1/60 second.

Therefore, recently, an electronic shutter function has been developed to reduce blurring of images even when fast-moving subjects are photographed. As shown in FIG. 12(a), this electronic shutter function generates a field shift pulse FS at the beginning of one field period, transfers unnecessary charges accumulated in the photoelectric conversion section to the vertical transfer section, and then A sweep pulse HD is generated to sweep out unnecessary charges in the vertical transfer section at high speed. Thereafter, a field shift pulse FS2 is generated, and the signal charges accumulated in the photoelectric conversion section are transferred to the vertical transfer section from the time when the field shift pulse FS is generated until the time when the field shift pulse FS2 is generated.

Thereafter, the signal charges transferred to the vertical transfer section by the line shift pulse LS are transferred line by line to the horizontal transfer stage and output, and here, as shown in FIG. Signal A is output. Note that the period in which the field shift pulses FS, FS2 and sweep pulse HD are generated is a vertical blanking period. According to such an electronic shutter function, the photoelectric conversion section is exposed to light and charges are accumulated only during the period from when the field shift pulse FSl is generated until when the field shift pulse FS2 is generated, so that the movement Even when photographing a fast subject, image blur can be reduced. Here, the period from when the field shift pulse FSI is generated until when the field shift pulse FS2 is generated, that is, the exposure time, should be longer than the pulse width of the sweep pulse HD.

With such an electronic shutter function, it is now possible to shorten the exposure time within one field period to a few tenths of a second.
It has become possible to capture clear, blur-free images even of fast-moving subjects.

However, in conventional electronic camera devices equipped with the above-mentioned electronic shutter function, although the exposure time for each photoelectric conversion unit is short and the images for each frame are clear, only one image is captured within one field period. Since exposure is performed only once, a problem arises in that the temporal resolution of the image becomes low when a fast-moving subject is photographed.

(Problems to be Solved by the Invention) As described above, while the images captured by conventional electronic camera devices equipped with an electronic shutter function are clear, they have a problem in that the temporal resolution of the images is low. .

Therefore, the present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an extremely good electronic camera device that can take clear images with high temporal resolution.

[Configuration of the Invention (Means for Solving the Problems) The electronic camera device according to the present invention sweeps out unnecessary charges within one field period from a photoelectric conversion unit installed on the light receiving surface of a solid-state image sensor. It is intended for devices that read signal charges and record the read signal charges on a recording medium.

Then, the photoelectric conversion unit is caused to sweep out unnecessary charges and read signal charges multiple times within one field period, and the photoelectric conversion unit corresponding to a predetermined light receiving area on the light receiving surface is read out multiple times within one field period. The structure is such that the signal charges read out twice are taken out as the output of the solid-state image sensor.

(Function) According to the above configuration, multiple frames can be photographed within one field period, so it is possible to photograph clear images with high temporal resolution.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. In FIG. 2, 11 is a solid-state image sensor,
Various pulses output from the horizontal drive circuit 12 and the vertical drive circuit 13 control the sweeping out of unnecessary charges, the vertical and horizontal transfer of signal charges, etc.
A video signal is extracted. The video signal taken out from the solid-state image sensor 11 is subjected to processing such as noise reduction and gamma correction by the first signal processing circuit 14, and then subjected to color separation, modulation, and synchronization signal by the second signal processing circuit 15. After processing such as addition, the data is recorded on a tape (not shown) by a VTR (video tape recorder) 16. Further, the video signal recorded on the tape is taken out from the output terminal 17 by reproducing the VTR1B, and is displayed as an image on a television receiver or the like (not shown). Note that the above-mentioned horizontal drive circuit 12. Vertical drive circuit 13. The first and second signal processing circuits 14 and 15 are controlled by a control circuit 18 that includes a microcomputer or the like.

Next, specific driving means for the solid-state image sensor 11 by the horizontal drive circuit 12 and vertical drive circuit 13 will be explained with reference to FIG. That is, as shown in FIG. 1(a), a field shift pulse FSz is generated at the beginning of one field period, and after transferring the unnecessary charges accumulated in the photoelectric conversion section to the vertical transfer section, a sweep pulse HD,...
is generated to sweep away unnecessary charges in the vertical transfer section at high speed. Thereafter, a field shift pulse FSI2 is generated, and the signal charges accumulated in the photoelectric conversion section are transferred to the vertical transfer section during the period from when the field shift pulse FS++ is generated until when the field shift pulse FS1□ is generated.

Thereafter, the signal charges transferred to the vertical transfer section by the line shift pulse L S z are transferred line by line to the horizontal transfer stage and output. In this case, the line shift pulse L S s+ shifts signal charges corresponding to, for example, 173 lines from the side closest to the horizontal transfer stage, out of the signal charges corresponding to all lines for one field accumulated in the vertical transfer section. As many signals as can be output from the horizontal transfer stage are generated. That is, from the solid-state image sensor 11, the signal charge corresponding to the light-receiving area of 1/3 of the entire light-receiving surface on the side closer to the horizontal transfer stage is transmitted to one field of one field as shown in FIG. 1(b).
73 is output as a video signal ■.

Next, after the line shift pulse L S z is generated, as shown in FIG. 1(a), the field shift pulse FS13 is generated.
is generated, and the unnecessary charges accumulated in the photoelectric conversion section are transferred to the vertical transfer section. Then, after generating sweep pulses HD and □ to sweep out unnecessary charges in the vertical transfer section at high speed, field shift pulse FS14 is generated, and after field shift pulse FS13 is generated, field shift pulse FS14 is generated. The signal charges accumulated in the photoelectric conversion section are transferred to the vertical transfer section.

Thereafter, the signal charges transferred to the vertical transfer section by the line shift pulses LS and □ are transferred line by line to the horizontal transfer stage and output. In this case, the line shift pulse LS, □ is also a signal charge corresponding to 1/3 line from the side near the horizontal transfer stage among the signal charges constituting all lines for one field accumulated in the vertical transfer section. are generated as many times as can be output from the horizontal transfer stage. That is, the solid-state image sensor 11 outputs signal charges corresponding to the same light-receiving area as described above as a video signal ■ as shown in FIG. 1(b).

Next, after the generation of the line shift pulse L S ,2, the first
As shown in figure (a), field shift pulse F S
, , and transfer unnecessary charges accumulated in the photoelectric conversion section to the vertical transfer section. And sweep pulse HD 1
．． is generated to sweep out unnecessary charges in the vertical transfer section at high speed, and then a field shift pulse F S ,6 is generated,
Between the generation of field shift pulse FS15 and the generation of field shift pulse FS,6,
The signal charges accumulated in the photoelectric conversion section are transferred to the vertical transfer section.

Thereafter, the signal charges transferred to the vertical transfer section by the line shift pulse LSI3 are transferred line by line to the horizontal transfer stage and output. In this case, the line shift pulse L S +i is also a signal charge corresponding to 1/3 of the lines from the side near the horizontal transfer stage among the signal charges constituting all the lines for one field accumulated in the vertical transfer section. are generated as many times as can be output from the horizontal transfer stage. That is, the solid-state image sensor 11 outputs signal charges corresponding to the same light-receiving area as described above as a video signal ■ as shown in FIG. 1(b).

According to the driving means for the solid-state image sensor 11 as described above, 1
Since exposure is performed three times in a field period (1/80 seconds), the time-axis resolution can be increased to 17180 seconds, and it is possible to sufficiently deal with fast-moving subjects. It also has an electronic shutter function, so you can get clear images.

Here, when the video signals (■, ■, ■) for one field obtained by the above-mentioned driving means are displayed on a television receiver, the image is displayed at 1/180 as shown in FIG.
Three images taken at intervals of seconds will be displayed simultaneously. Since these three frames of images correspond to one field of video signals in the current format, they can be easily recorded and played back on the current VTR1B.

Also, by using a field memory (not shown), as shown in FIG. Two images ■.

If only (1) is displayed sequentially, the normal 173 images on the effective screen will be obtained at 1/60 second intervals, as shown in FIG. 3(b). Furthermore, as shown in FIG. 5(a), if a field memory is used to sequentially display three frames of images obtained in one field period from the top at regular intervals every m (m≧2) fields, As shown in FIG. 5B, the effective screen is a normal 173 images, and slow playback can be performed at 1/180 second intervals.

Here, in order to detect n from n (n=3 in the above embodiment) video signals obtained in one field period as described above, sweep pulse HDII (D2.HD3...
It is possible to use the blank of the high-speed sweep period by .... That is, during this high-speed sweep period, the solid-state image sensor 11 does not output a video signal and remains blank. By detecting this blank (the black level continues for several lines) and finding the position of this blank or the number of lines in one field, the above n can be obtained. This n is used as information when controlling the field memory. It is also possible to digitally add information such as a code to this blank period, and it is also possible to display elapsed time, shutter speed, etc. on the final television screen.

Next, in the above embodiment, the effective screen is a horizontally long area that is 1/3 of the television screen in the vertical direction, but by changing the configuration of the solid-state image sensor 11, the aspect ratio of the effective screen can be changed. I can do it. First, FIG. 6 shows the configuration of a conventionally used solid-state image sensor. That is, numeral 19 in the figure is an image section consisting of a photoelectric conversion section and a vertical transfer section, and a horizontal transfer stage 20 is installed at the bottom of the image section. Then, by horizontally transferring the signal charges transferred from the vertical transfer section to the horizontal transfer stage 20 using a horizontal transfer pulse, one line of signal charges is taken out from the output terminal 22 via the output amplifier 21.

Here, the horizontal transfer stage 20 includes a sweep gate 23.
A drain 24 is added via the drain. A DC voltage from a DC voltage source 25 is applied to this drain 24 . When horizontally transferring the signal charges transferred to the horizontal transfer stage 20, a gate pulse GP is supplied to the sweep gate 23 before horizontal transfer of all the charges is completed, and the signal charges remaining in the horizontal transfer stage 20 are removed. It is controlled so that it is swept out to the drain 24. Thereafter, the signal charges for the next one line are transferred from the vertical transfer section to the horizontal transfer stage 20, and the same operation is repeated thereafter.

According to such a driving means, for example, half of the signal charges in the horizontal transfer stage 20 are horizontally transferred, the remaining part is swept out, and the signal charges for the next one line are transferred to the horizontal transfer stage 20, thereby horizontally transferring the signal charges to the horizontal transfer stage 20. During the period in which the transfer stage 2° outputs the signal charges for one line, it is possible to output half the signal charges for two lines at a time.

Therefore, we modified the solid-state image sensor shown in FIG.
As shown in the figure, the sweep gate 26 and the drain 27
are installed in the center of the horizontal transfer stage 20, and DC voltage is applied from DC voltage sources 28 and 29, respectively. By doing this, when the signal charges transferred to the horizontal transfer stage 20 are transferred by the horizontal transfer pulse, the signal charges on the right side in the figure are swept out from the sweep gate 26,
Only half of the signal charge of one line on the left side of the figure is output from the sweep gate 26. For this reason, 1
After the signal charges for half of the line are output, by transferring the signal charges for the next one line to the horizontal transfer stage 20,
As shown in FIG. 6, there is no need to install a sweep gate 23 or a drain 24 in the entire area of the horizontal transfer stage 20, or to generate a gate pulse GP and supply it to the sweep gate 23. During the period in which signal charges for a line are output, half of the signal charges for two lines can be output at a time.

That is, horizontal transfer pulses are supplied to the horizontal transfer stage 20 twice in one horizontal transfer period, as shown by diagonal lines in FIG. 8(a). Furthermore, the solid-state image sensor shown in FIG. 7 is exposed three times within one field period, as shown in FIG. 8(b).

By driving in this manner, only the signal charges in the light-receiving area indicated by diagonal lines in FIG. 9 out of the entire light-receiving surface of the solid-state image sensor, that is, the image section 19, are repeatedly read out. When the video signal thus obtained is adapted to the current format, an image as shown in FIG. 10 is displayed. In this case, two lines worth of signal charges are output during one horizontal transfer period, so the line (
1).

Horizontal scanning is performed in the order (2) to form an image.

Next, the present invention is not only applicable to cameras using an electronic shutter function as shown in FIG. 1, but also widely applicable to cameras that do not use an electronic shutter function. That is, as shown in FIG. 11(a), at the beginning of one field period, sweep pulse HD2. is generated to sweep away unnecessary charges in the vertical transfer section at high speed. after that,
A field shift pulse FS21 is generated to transfer the signal charges accumulated in the photoelectric conversion section to the vertical transfer section. Then, line shift pulse LS2. The signal charges transferred to the vertical transfer section are transferred line by line to the horizontal transfer stage for an area of 1/3 of the screen and output, as shown in Fig. 11(b).
A video signal a is obtained as shown in FIG.

After that, as shown in FIG. 11(a), the sweep pulse H
D22 is generated to sweep out unnecessary charges in the vertical transfer section at high speed, and a field shift pulse FS22 is generated. The signal charges accumulated in the conversion section are transferred to the vertical transfer section.

Similarly, signal charges are output line by line by line shift pulse LS2□ to obtain a video signal as shown in FIG. 11(b).

As mentioned above, even without using the electronic shutter function, the exposure time can be made shorter than the conventional one-field period, making it possible to reduce image blur even when photographing fast-moving subjects. .

It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications without departing from the gist thereof.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide an extremely good electronic camera device that can take clear images with high temporal resolution.

[Brief explanation of drawings]

1 and 2 are a timing diagram and a block configuration diagram, respectively, for explaining an embodiment of an electronic camera device according to the present invention, and FIG. 3 is a diagram for explaining a screen display of the embodiment, and FIG. 4 and 5 respectively show modified examples of the screen display of the same embodiment, FIG. 6 shows details of a conventional solid-state image sensor, and FIG. 7 shows a solid-state modified to be used in the present invention. Figure 8 is a timing diagram for explaining the driving of the modified solid-state imaging device; Figure 9 is a diagram showing the light-receiving surface of the modified solid-state imaging device; Figure 10 is a diagram showing the light receiving surface of the modified solid-state imaging device; A diagram for explaining the screen display by the modified solid-state image sensor, FIG. 11 is a timing diagram for explaining a modification of the same embodiment, and FIG. 12 is a timing diagram for explaining the conventional electronic camera device. It is. 11... Solid-state image sensor, 12... Horizontal drive circuit, 1
3... Vertical drive circuit, 14... First signal processing circuit, 15... Second signal processing circuit, 16... VTR,
17... Output terminal, 18... Control circuit, 1
9... Image section, 20... Horizontal transfer stage, 21...
- Output amplifier, 22... Output terminal, 23... Sweep gate, 24... Drain, 25... DC voltage source, 26... Sweep gate, 27... Drain, 2
8.29...DC voltage source.

Claims (1)

[Claims] In an electronic camera device that sweeps out unnecessary charges and reads signal charges within one field period from a photoelectric conversion unit installed on a light receiving surface of a solid-state image sensor, and records the read signal charges on a recording medium, The photoelectric conversion unit is caused to sweep out unnecessary charges and read signal charges multiple times within one field period, and the photoelectric conversion unit corresponding to a predetermined light receiving area of the light receiving surface is charged within one field period. An electronic camera device characterized in that the electronic camera device is configured to extract signal charges read out multiple times as an output of the solid-state image sensor.