JPH02196566A - Driving device for solid-state image pickup element - Google Patents

Abstract

PURPOSE:To attain convenient use of the user by switching a solid-state image pickup element automatically so as to be driven in the field storage mode and the pseudo frame shutter mode in response to a moving picture and a still picture. CONSTITUTION:A video output signal obtained from a signal processing circuit 14 is stored in a data memory 22, fed to a noninverting input terminal of an arithmetic circuit 23, the stored data is retarded by a delay circuit 24 and fed to an inverting input of the arithmetic circuit 23. Then a constant is multiplied with an absolute value of a differentiated (difference) value, the product is accumulated by an integration adder circuit 35 and the result is outputted from a control circuit 27. The control circuit 27 discriminates it as a still picture when an output level of the integration adder circuit 35 is lower than a reference level, a drive circuit 13 is selected and the control circuit 27 discriminates it as a moving picture when the output level is higher than the reference level, a drive circuit 12 is selected so as to switch automatically a solid-state image pickup element 11 in the field store mode or the pseudo frame shutter mode. Thus, the convenient use of the user is attained.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention relates to a solid-state image sensor used for example in an electronic camera or a video camera. The present invention relates to a driving device that automatically changes an image sampling interval.

(Prior Art) As is well known, solid-state imaging devices have been used in, for example, electronic cameras and video cameras to convert an optical image of a subject into a television signal. As shown in FIG. 4, this solid-state imaging device includes, for example, a semiconductor integrated circuit (CCD)
The solid-state image sensor 11 (IC) is connected to the drive circuit 12.1.
3, the optical image formed on the solid-state image sensor 11 is taken out in the form of a television signal by driving at a timing corresponding to a television signal. Note that the signal extracted from the solid-state image sensor 11 is subjected to predetermined processing in the signal processing circuit 14 and becomes a video output.

Here, the drive circuit 12 has a function of driving the solid-state image sensor 11 so as to sample the subject in units of fields of the television signal, and the drive circuit 13 has the function of
It has a function of driving the solid-state image sensor 11 so as to sample a subject in units of frames of a television signal. Then, the user switches the switch 15 depending on whether there is movement in the subject, that is, whether it is a moving image or a still image, and selects one of the drive circuits 12 and 13 to drive the solid-state image sensor 11.

Specifically, as shown in FIG. 5, the solid-state image sensor 11 has a plurality of (32 in the illustrated case) photoelectric conversion elements arranged in a plane in the horizontal and vertical directions, each of which constitutes a pixel. The elements te, te, . . . and the plurality of photoelectric conversion elements 16. Ift, . . . , two vertically adjacent elements 18.16. The photoelectric conversion elements 1 [i,
As signal charges of 1B, . . . are transferred,
A plurality of vertical transfer stages 17 capable of vertical charge transfer.
17. ...and these multiple vertical transfer stages 17.1
? , . . . , respectively, and the vertical transfer stages 17.17. A plurality of charge storage units 1g in which signal charges transferred in the vertical direction are stored by .
18. . . . and this arrogant charge storage section 18.
18. The signal charges accumulated in the vertical transfer stages 17.17. The horizontal transfer stage I9 is sequentially supplied in a form corresponding to vertical transfer by ..., and the output amplifier 20 amplifies and outputs the signal charge transferred to the horizontal transfer stage 19. A FIT (frame interline transfer) type is used.

First, the solid-state image sensor 1 is driven by the drive circuit 12.
The first driving method will be explained. That is, Fig. 6 (a
), in a television signal in which one frame is composed of an even field and an odd field, before the vertical blanking period of the even field, the drive circuit 12 performs a field shift as shown in FIG. A pulse FSI is generated, and the photoelectric conversion elements 16.1B, .
The residual charges of ...... are transferred to the vertical transfer stage 17.17. ...
It will be forwarded to... Thereafter, during the vertical blanking period, the sweep transfer pulse HTI shown in FIG. 6(c) is generated from the drive circuit 12, and the vertical transfer stages 17, 17. ...
The residual charge transferred to the vertical transfer stage 17.17
．． . . . are swept out by high-speed transfer.

Next, during the same vertical blanking period, the field shift pulse FS2 shown in FIG. 6(b) is generated from the drive circuit 12, and the field shift pulse FSI is generated first as shown in FIG. 7(a). From then until now, signal charges A1 to A8 . Bl~Bg.

C1-C8, DI-D8 are vertical transfer stages 17°17,・
Transferred to...

At this time, the signal charges Al -A8, Bl -88
.

CI-C8 and Dl-D8 are vertical transfer stages 17°17,
......by AI and A2. A3 and A4゜A5
and A6. A7 and A8. Bl and B2. B3 and E! 4. B5
and Be, B7 and B8. CI and C2° C3 and C4, C5 and CB, C7 and C8, Di and D2. D3 and D4. D5 and D
[i, D7 and D8 are transferred so that they are each added.

Thereafter, during the same vertical blanking period, the frame transfer pulse FTI shown in FIG. 6(C) is generated from the drive circuit 12, and the vertical transfer stages 17, 17. The signal charges of . . . are transferred to the charge storage sections 18.1B, . . . at high speed. Then, every horizontal blanking period of the television signal, line shift pulses LSI to LS4 shown in FIG. 6(d) are generated from the drive circuit 12, and the charge storage section 18.
The signal charges accumulated in 1B, . By taking out the signal through the amplifier 20, a video signal 5l-54 for each horizontal line is obtained.

In this case, each video signal 5t-34 is expressed as Sl −At +A2, Bl +B2, CI
10C2.

Di +D2 S2 =A3 +A4, B3 +i34,
C3'+C4.

D3 +D4 S3 =A5 +A6, B5 +B6, C
5+CG.

D5 +DB S4 =A7 +A8, B7 +B8, C7+
C8.

DI +D8 becomes.

Next, in the odd field of the television signal, the field shift pulse FS3 shown in FIG. 6(b) is generated from the drive circuit 12 before the vertical blanking period, and the photoelectric conversion elements +e, te, . . . . . . The residual charge of the vertical transfer stage +7.1.7. Transferred to...

Thereafter, during the vertical blanking period, the sweep transfer pulse HT2 shown in FIG. 6(c) is generated from the drive circuit 12, and the vertical transfer stages 17, 17. The residual charges transferred to the vertical transfer stages 17.17. . . . are swept out by high-speed transfer.

Next, during the same vertical blanking period, the drive circuit 12 generates the field shift pulse FS4 shown in FIG. 6(b), and as shown in FIG. 7(b), the field shift pulse FS3 is generated first. From then until now, photoelectric conversion elements IG, 16. Signal charges AI-A8, Bl-B8 accumulated in .

C1 to CB, DI to D8 are vertical transfer stages 17°17, .
Transferred to...

At this time, signal charges A1 to A8. Bl~Bg.

C1 to C8, DI to D8 are vertical transfer stages 17, 17, . By...A
2 and A3. A4 and A5. AG and A7. B2 and B3. B4
and B5. BG and 87. C2 and C3゜C4 and C5, Cfl
and C7, D2 and D3. D4 and D5. DO and DI are transferred so as to be added to each other.

Thereafter, during the same vertical blanking period, the frame transfer pulse FT2 shown in FIG. +7. The signal charges of . . . are stored in the charge storage section 18. It will be transferred at high speed to... Then, line shift pulses LS5 to LS8 shown in FIG. 6(d) are generated from the drive circuit 12 every horizontal blanking period of the television signal, and the charge storage section 18
．． The signal charges accumulated in 1B, . By taking out the signal through the output amplifier 20, video signals 85 to S8 for each horizontal line are obtained.

In this case, each video signal 85 to S8 is S5-AI, Bl, C1, DI S8-A2 +A3, B2 +83, C2+C
3.

D2 +D3 S7-A4 +A5, B4 +85, C4
+C5.

D4 +D5 S8-A6 +A7, BG +87, CG
10C7.

DB +D7 becomes.

Next, the solid-state 1Iil image element 11 by the drive circuit 13 is
The driving method will be explained. That is, FIG. 8(a)
As shown in the even and odd fields]
, in a television signal in the form of a frame, before the vertical blanking period of the even field, the field shift pulse FS5 shown in FIG.・
The residual charges of ...... are transferred to the vertical transfer stage 17.1.7.・・・
Transferred to... Thereafter, during the vertical blanking period, the drive circuit 13 generates a sweep transfer pulse HT3 shown in FIG. 8(C), and the vertical transfer stages 17, 17.・・・
The residual charge transferred to the vertical transfer stage 17.1
7. . . . are swept out by high-speed transfer.

Next, during the same vertical blanking period, the field shift pulse FSO shown in FIG. 8(b) is generated from the drive circuit 13, and the field shift pulse FS5 is generated first as shown in FIG. 9(,a). From then until now,
Signal charges A2. accumulated in the photoelectric conversion elements 16.1B, . . . A4. AB, A8°B2. B4. B6. B
8. C2, C4, CB.

C8, D2. D4. D8. D8 is the vertical transfer stage 17°1
? ,... will be forwarded to.

At this time, signal charge A1. A3. A5. A7゜Bl, B
3. B5. B7. C1, C3, C5° C7, Di, D3
．． D5. Photoelectric conversion element 18.1B corresponding to DI,...
..., the photoelectric conversion operation is still being performed.

Thereafter, during the same vertical blanking period, the drive circuit 13 generates a frame transfer pulse FT3 shown in FIG. 8(C), and the vertical transfer stages 17, 17. The signal charges of . . . are stored in the charge storage section 18. It will be transferred at high speed to... Then, every horizontal blanking period of the television signal, line shift pulses LS9 to LS12 shown in FIG. 8(e) are generated from the drive circuit 13, and the charge storage section 18
．． The signal charges accumulated in 1g, . By being taken out via the amplifier 20, the video signal S2. S4゜Si2. S8 is obtained.

In this case, each video signal S2. S4. S13. S8 is S2-A2. B2. C2D2 S4-A4. B4. C4, D4S6-A8.
B8. CB, DO38-A8. Bg,
They become C8 and D8.

Next, in the odd field of the television signal, a field shift pulse FS7 is generated from the drive circuit 13 at the timing shown in FIG. 8(d), and the photoelectric conversion element te,
The residual charge of te,... is at the vertical transfer stage 17°17
,... will be forwarded to. Thereafter, by the sweep transfer pulse HT3 generated by the drive circuit 13,
Vertical transfer stage 17.17. The residual charges transferred to the vertical transfer stages 17.17. . . . are swept out by high-speed transfer.

Next, the field shift pulse FSII shown in FIG. 8(d) is generated from the drive circuit 13, and as shown in FIG. 9(b), the period from the previous generation of the field shift pulse FS7 to the present , photoelectric conversion element 1B, Ifi,
Signal charge AI accumulated in ......

A3. A5. A7. Bl, B3. B5. B7゜CI,C
3, C5, C7, DI, D3. D5°DI is the vertical transfer stage 17.17. Transferred to...

Thereafter, during the vertical blanking period of the odd field, the frame transfer pulse F shown in FIG. 8(c) is sent from the drive circuit 13.
T4 is generated and the vertical transfer stage 17°1? ,・・・・・・
The signal charge is the charge storage part! 8.18. It will be transferred at high speed to... Then, in each horizontal blanking period of the television signal, line shift pulses LS13 to LSI (i) shown in FIG. The signal charges accumulated in ... are sequentially transferred in the vertical direction to the horizontal transfer stage 19 for 17 minutes per vertical transfer stage, and as shown in FIG. By taking out the video signals SL, S3.S5.
S7 is obtained.

In this case, each video signal Sl, S3 . S5. S7 is 5t-AI, Bl, C1, DIS3-A3
, B3. C3, D3S5-A5. B5.
C5, D5S7-A7. B7. It becomes C7, DI.

As described above, in the drive circuit 12, the photoelectric conversion elements te,
tc, . . . to vertical transfer stage 17.17.・・・
The movement of signal charges to ... is performed in the vertical blanking period of even fields and the vertical blanking period of odd fields, that is, the subject is sampled in field units (field accumulation mode). Become. Further, in the drive circuit 13, the photoelectric conversion elements is, te, . . .
, . . . , the signal charge is moved for two fields during the vertical blanking period of the even field.
In other words, the subject is sampled frame by frame (
pseudo frame shutter mode).

By the way, field accumulation mode has the advantage of reducing afterimages when photographing fast-moving subjects, but on the other hand, under fluorescent lighting in areas where the power frequency is 50 Hz, flickering occurs and the screen flickers. A problem arises. Further, in the pseudo frame shutter mode, although the afterimage is large in the case of a moving image, the difference in video signals between fields in one frame is small, so the effect of flicker can be reduced.

For this reason, conventionally, the user operates the switch 15 shown in FIG. 4 to select the drive circuit 12 to set the field accumulation mode when the subject is moving, and when the subject is stationary. The drive circuit 13 is selected to enter the pseudo frame shutter mode.

However, with the conventional driving means for solid-state image sensors as described above, the user has to manually switch switch 5 depending on whether the image is a moving image or a still image, resulting in the problem of cumbersome handling. .

(Problems to be Solved by the Invention) As described above, in the conventional solid-state image sensor driving means, the drive mode of the solid-state image sensor is manually switched depending on whether the image is a moving image or a still image. The problem is that it is inconvenient.

Therefore, the present invention was made in consideration of the above circumstances, and it automatically switches the solid-state image sensor to drive in field accumulation mode and pseudo frame shutter mode depending on the moving image and still image, making it easier for the user to handle the device. It is an object of the present invention to provide a convenient and extremely good driving device for a solid-state image sensor.

[Structure of the Invention] (Means for Solving the Problem) A driving device for a solid-state image sensor according to the present invention includes a storage means for storing a video signal output from a horizontal transfer stage of the solid-state image sensor, and a storage means for storing a video signal output from a horizontal transfer stage of the solid-state image sensor. 'ELL discrimination means for determining whether the image is a moving image or a still image based on the difference component between the stored video signal and the video signal supplied to the storage means; a first driving means for driving the image sensor to sample a subject image on a field-by-field basis; and a first driving means for driving the solid-state image sensor so as to sample a subject image on a frame-by-frame basis when the image is determined to be a still image by the determining means. and a second driving means.

(Function) According to the above configuration, it is determined whether the image is a moving image or a still image, and the solid-state image sensor is automatically switched to sample the subject image in field units and frame units. The solid-state image sensing device can be automatically switched to be driven in the field accumulation mode and the pseudo frame shutter mode according to the situation, thereby making handling convenient for the user.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. In FIG. 1, the same parts as in FIG. 4 are indicated by the same symbols, and only the different parts will be described here. In other words, the video output signal obtained from the signal processing circuit 14 is supplied to an A/D (analog/digital) conversion circuit 21 and converted into digital data, and then stored in the data memory 22.

The digital data recorded in the data memory 22 is supplied to the positive input terminal of the 7'j1 arithmetic circuit 23. Further, the digital data stored in the data memory 22 is processed by the delay circuit 24, for example, m(1, 2, . . .
...) is delayed by the end corresponding to the frame, is taken out in synchronization with the vertical synchronizing pulse, and is supplied to the negative input terminal of the arithmetic circuit 23. Therefore, the arithmetic circuit 23 has
Digital data corresponding to the same pixel shifted in the time axis direction by m frames is supplied.

Then, the arithmetic circuit 23 calculates the absolute value of the differential (difference) between the two input digital data or multiplies the absolute value by a constant, and outputs the result to the integral addition circuit 25 . In this case, the data memory 22 and the arithmetic circuit 23 are connected to a memory controller 26 which is driven in synchronization with a vertical synchronizing pulse based on a control value given from the outside.
From there, instructions and control of pixels to be subjected to calculations are performed.

Here, the integral addition circuit 25 cumulatively adds the output of the arithmetic circuit 23 and outputs the result to the control circuit 27. The control circuit 27 compares the output level of the integral addition circuit 25 with a reference level, determines that it is a still image when the output level is lower than the reference level, and sends the drive circuit 1 to the switch 15.
A control signal is generated to select 3. In addition, the control circuit 2
7 determines that it is a moving image when the output level of the integral addition circuit 25 is higher than the reference level, and generates a control signal for causing the switch 15 to select the drive circuit 12.

For this reason, the solid-state image sensor 11 is automatically switched to be driven in field accumulation mode by the drive circuit 12 in the case of moving images, and driven in the pseudo frame shutter mode by the drive circuit 13 in the case of still images. This makes it easier for people to handle the product.

Here, selection of pixels used to determine whether an image is a moving image or a still image will be explained. First, as shown in FIG. 2, the control values given to the memory controller 2B are as follows:
The start address and end address of pixel data for one field are set.

Then, the memory controller 2B controls writing and reading of data to and from the data memory 22 based on the set control values, and motion detection is performed in the entire field.

Further, as a control value given to the memory controller 26,
As shown in FIG. 3, the start and end addresses of data for pixels in the center of the screen of one field are set. Then, motion detection is performed using pixels in the center of the screen.

Furthermore, the memory controller 26 determines which position of the pixel on the screen the two digital data to be processed by the arithmetic circuit 23 are located in the center of the screen based on the input horizontal synchronization signal and vertical synchronization signal. Weighting information is generated in the arithmetic circuit 23 so that pixel data close to . In this case, the weighting information can be set by experiment, similar to the reference level for distinguishing between moving images and still images.

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 detailed above, according to the present invention, the solid-state image sensor is automatically switched to be driven in the field accumulation mode and the pseudo frame shutter mode depending on moving images and still images, and the user's handling is easy. Accordingly, it is possible to provide an extremely good driving device for a solid-state image sensor that can conveniently perform operations.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram showing an embodiment of a driving device for a solid-state image sensor according to the present invention, FIGS. 2 and 3 are diagrams for explaining types of motion detection in the embodiment, respectively, and FIG. The figure is a block diagram showing the driving means of a conventional solid-state image sensor, FIG. 5 is a diagram showing the structure of an FIT type solid-state image sensor, and FIGS. 6 and 7 are diagrams for explaining the field accumulation mode, respectively. , FIG. 8, and FIG. 9 are diagrams for explaining the pseudo frame shutter mode, respectively. 11... Solid-state image sensor, 12.13... Drive circuit,
14... Signal processing circuit, 15... Switch, 16.
...Photoelectric conversion element, 17...Vertical transfer stage, 18...
Charge storage section, 19... horizontal transfer stage, 20... output amplifier, 21... A/D conversion circuit, 22... data memory, 23... arithmetic circuit, 24... delay circuit, 25
...integral addition circuit, 26...memory controller,
27...Control circuit. Applicant's representative Patent attorney Takehiko Suzue Figure 3 Figure 4 (a)

Claims (1)

[Claims] A plurality of photoelectric conversion elements are arranged in a plane in the horizontal and vertical directions, each forming a pixel, and the signal charges of the photoelectric conversion elements are installed corresponding to the elements in the vertical direction of the plurality of photoelectric conversion elements. A plurality of vertical transfer stages are installed corresponding to each of the plurality of vertical transfer stages, and signal charges transferred vertically by the vertical transfer stages are accumulated. a plurality of charge storage sections, and a horizontal transfer stage to which signal charges accumulated in the plurality of charge storage sections are sequentially supplied in a form corresponding to vertical transfer by the vertical transfer stage. in a driving device for a solid-state image sensor that samples a subject image at predetermined intervals; a determining means for determining whether the image is a moving image or a still image based on a difference component between the video signal and the video signal supplied to the storage means; a first driving means for driving the subject image in units of frames, and a second driving means for driving the solid-state image sensor so as to sample the subject image in frame units in a state determined as a still image by the discrimination means. 1. A driving device for a solid-state image sensor, comprising: a driving means.