JP2007329658A - Imaging apparatus and driving method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of suppressing flickers in frame in rolling shutter operation by CMOS sensor, and to provide a driving method of the imaging apparatus. <P>SOLUTION: Images of shutter speed 1/100 sec and 1/120 dec are photographed consecutively, and the luminance values are compared in the plurality of regions that are in common; and when values are different from each other, it determines that flickers are being genrated. When flickers are generating, batch reset/batch FD transmission for all line are carried out. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an imaging apparatus and a driving method of the imaging apparatus.

  Conventionally, many CMOS image sensors have an electronic shutter function.

  Unlike a CCD image sensor, a CMOS type image sensor is a focal plane shutter (rolling shutter) that sequentially scans a number of two-dimensionally arranged pixels for each pixel row and resets the signal. There is a problem that the exposure period is shifted.

  In this case, for example, when shooting in a place where a fluorescent lamp is used as a light source such as indoors, periodic luminance unevenness in the horizontal line direction within one screen is caused by the fluorescent lamp blinking by an AC power source. (In-plane flicker) occurs.

  As shown in FIG. 9A, after each row is reset, an operation of transferring and outputting (signal reading) after a predetermined exposure time is sequentially performed in each row.

  As a result, in an image taken under a fluorescent lamp, for example, as shown in FIG. 9C, periodic luminance unevenness appears in the vertical direction.

  On the other hand, in order to prevent the occurrence of the luminance village, a CMOS sensor is known that can release the shutter simultaneously for all rows.

  In that case, the photodiodes (PD) are reset by discharging the charges simultaneously for all the rows at a certain point in time, and after a predetermined exposure time, the charges of the PD are transferred to the floating diffusion (FD) simultaneously for all the rows. Signals are output one line at a time.

  FIG. 9B is an explanatory diagram showing the situation, after all rows are collectively reset, all rows are transferred simultaneously, and then output is performed for each row. By so doing, as shown in FIG. 9D, for example, even in an image taken under a fluorescent lamp, luminance unevenness in the vertical direction does not occur.

Also, as a pixel circuit configuration for simultaneously resetting the PD signal charges of all pixels in a CMOS type image sensor, there is also provided a transistor that can discharge the PD surplus charges directly to the drain without going through the FD. Proposed. (Patent Document 1)
However, the all-pixel shutter CMOS image sensor shown in FIG. 9B has the following problems.

  (1) Since the PD is reset after the information of all lines is output, the exposure cannot be performed until the information of all lines is output one line at a time after all lines are simultaneously transferred, and time is wasted. Further, since it is difficult to take a long exposure time, proper exposure cannot be obtained when the subject is dark.

  (2) The light leaks into the FD after all the lines are transferred at the same time until the pixels are output in order, and the amount of the light is different between the first output line and the later output line. make worse.

  (3) The image quality is deteriorated due to the dark current generated in the FD and the recombination of electric charges between the transfer of all rows at the same time and the sequential output for each pixel row, and this level is vertical. The pixels differ greatly depending on the direction, and the pixels that are read out more slowly deteriorate.

Therefore, in order to solve (1) and (2) and release the shutter simultaneously for all rows, the PD signal charge can be discharged without going through the FD, and the signal charge is sequentially read out from the FD pixel by pixel. There has been proposed an improvement in which the signal charge of the PD is reset and exposure of the next frame is started even from the middle. (Patent Document 2)
However, even in the above-described means, signal deterioration due to dark current or charge recombination due to charge being left in the FD portion for a long time cannot be avoided.
JP 2001-238132 A JP 2004-140149 A

  However, the conventionally proposed method does not generate a luminance village in a captured image under a flicker light source, and cannot solve all the problems (1), (2), and (3).

  The present invention is an imaging device having a large number of pixels arranged two-dimensionally, has a focal plane shutter that sequentially scans every pixel row and resets a signal, and has a moving image shooting or EVF display function.

  Further, flicker detection means for detecting a flicker amount due to a periodic light quantity change of light illuminating the subject, and flicker determination means for determining whether the flicker amount obtained by the flicker detection is a predetermined value or more. Have.

  Further, a batch reset unit that discharges charges from the PD at the same time for pixels in a predetermined region of the image sensor, and an image pickup that has a batch FD transfer unit that simultaneously transfers charges from the PD to the FD for pixels in the predetermined region of the image sensor. Device.

  Also, flicker determination is performed to determine whether or not the amount of flicker obtained by flicker detection is equal to or greater than a predetermined value. If it is determined that flicker has occurred as a result, it is collectively performed during movie shooting or EVF display frames. An imaging apparatus characterized by performing reset and batch FD transfer and a driving method thereof.

  The flicker detection means of the image pickup apparatus according to the present invention uses two images taken at shutter speeds n / 100 sec and m / 120 sec, where n and m are arbitrary integers.

  The flicker determination means of the imaging apparatus according to the present invention detects a luminance value of a plurality of common areas of two images taken at a shutter speed of n / 100 sec and m / 120 sec, and the difference value is a certain constant value. It is determined whether or not the flicker amount changes the driving method of the image sensor.

  The flicker detection frame of the image pickup apparatus according to the present invention is exposed by a focal plane shutter.

  The flicker detection means of the imaging apparatus according to the present invention is characterized in that the flicker detection frame is exposed separately from a moving image shooting or EVF display frame.

  In addition, the flicker detection frame is subjected to exposure at a shutter speed n / 100 sec before a moving image shooting or EVF display frame, and a shutter speed n / 100 is sandwiched between the moving image shooting or EVF display frame. 120 sec exposure is performed.

  In the imaging apparatus according to the present invention, the flicker detection frame is first subjected to exposure at a shutter speed of n / 120 sec before the moving image shooting or EVF display frame, and the moving image shooting or EVF display frame is sandwiched between the frames. , Exposure is performed at a shutter speed of n / 100 sec.

  The flicker detection frame of the image pickup apparatus according to the present invention is subjected to exposure at a shutter speed n / 120 sec before a moving image shooting or EVF display frame, and immediately after or immediately before the exposure at a shutter speed n / 100 sec. I do.

  The flicker detection frame of the image pickup apparatus according to the present invention is such that exposure at a shutter speed n / 100 sec is performed first after a moving image shooting or EVF display frame, and an exposure at a shutter speed n / 120 sec immediately after or immediately before. I do.

  The values of arbitrary constants n and m of the imaging apparatus according to the present invention are 1.

  In other words, in order to perform shooting while suppressing flicker under a condition where a light source such as a fluorescent lamp periodically blinks, after performing shutter operation and transfer operation (collective exposure) simultaneously for all pixels, from the FD section An operation of sequentially reading signal charges in units of pixel rows is performed.

  Furthermore, the use of batch exposure is performed only when flicker detection is performed and as a result it is determined that flicker has occurred, so that charges are left in the FD portion for a long time except under a light source where flicker occurs. Therefore, signal degradation due to dark current and charge recombination can be avoided.

  In this way, flicker detection is performed, and flicker detection is performed using a frame other than a frame for shooting a moving image or displaying an EVF, so that batch exposure for flicker suppression is performed only when necessary. Otherwise, line exposure with less noise is performed.

  As a result, noise can be reduced when flicker is not generated, and can be suppressed under a light source that generates flicker such as under a fluorescent lamp.

Example 1
In the following, Example 1 of the present invention is shown.

  FIG. 1 is a circuit block diagram for explaining the configuration of an imaging signal processing system and a sensitivity / exposure control system of a digital still camera and a digital camcorder using a solid-state imaging device.

  Reference numeral 101 denotes a lens for forming an object on the image plane, 102 denotes a stop for controlling the amount of image plane light from the lens, and 103 denotes a mechanical for irradiating light from the lens on the image plane only for a necessary time. It is a shutter.

  Reference numeral 104 denotes a solid-state imaging device for converting an imaged light image into an electrical signal. A CCD area sensor is mainly used, but in recent years, an XY address type CMOS area sensor is increasingly used. ing.

  Therefore, the following description will be made using a CMOS area sensor.

  Reference numeral 105 denotes an image sensor driving circuit that supplies a pulse having a necessary amplitude for driving the CMOS area sensor. Reference numeral 106 denotes a CDS circuit that performs double correlation sampling on the output of the CMOS area sensor.

  Reference numeral 107 denotes an AGC circuit for amplifying the output signal of the CDS circuit. When the user changes the sensitivity setting of the camera as desired, or when the camera automatically increases the gain at low luminance, the gain setting of this circuit is set. Will be changed.

  Reference numeral 108 denotes a clamp circuit for clamping an OB potential, which will be described later, to a reference potential among the output signals of the AGC circuit, and reference numeral 109 denotes an AD conversion circuit that converts an analog imaging signal output from the clamp circuit into a digital signal.

  Reference numeral 110 denotes a video processing circuit, which processes an imaging signal converted into a digital signal into a video signal of luminance and color (R-Y, BY color difference signals or R, G, B signals). 111, a photometric circuit 112 that measures the photometric amount from the signal level of the CMOS area sensor.

  Although not shown in the drawing, it is constituted by a WB circuit that measures the color temperature of a subject from an input CMOS area sensor signal and extracts information necessary for white balance of the video signal processing circuit.

  Reference numeral 113 denotes a timing pulse generation circuit that generates a timing pulse necessary for circuits in each part of the camera.

  A CPU 114 controls the camera. Based on the information of the photometry circuit, a command for changing the gain of the AGC circuit is issued or the exposure control circuit 116 is exposed to control sensitivity and exposure. It has a function to issue such commands.

  FIG. 2 is a circuit configuration diagram showing a conventional solid-state imaging device using a conventional CMOS area sensor.

  A transfer transistor 204 for transferring the signal charge of the photodiode 201 to the floating diffusion (FD) 203, an amplification transistor 202 for amplifying the detection signal, a vertical selection transistor 205 for selecting a signal readout line, and resetting the signal charge Unit cells composed of reset transistors 206 are arranged in a two-dimensional matrix.

  In the figure, 3 × 3 cells are arranged, but actually more unit cells are arranged.

  A horizontal address line 208 wired in the horizontal direction from the vertical shift register 207 is connected to the gate of the vertical selection transistor 205 to determine a line for reading a signal.

  Similarly, the reset line 209 wired in the horizontal direction from the vertical shift register 207 is connected to the gate of the reset transistor 206.

  The source of the amplification transistor 202 is connected to a vertical signal line 210 arranged in the column direction, and a load transistor 211 is provided at one end thereof.

  The other end of the vertical signal line 210 is connected to the horizontal signal line 213 via a horizontal selection transistor 212 driven by a selection pulse of the horizontal shift register 212.

  Next, a flicker detection method in the present invention will be described.

  As will be described later, in the present invention, when flicker occurs, the exposure method of the moving image shooting or EVF display frame is switched from the rolling shutter to the all-pixel simultaneous exposure.

  FIG. 3A shows a rolling shutter drive in a normal CMOS. The vertical direction is the readout timing of each horizontal line, and the horizontal direction is the elapsed time. FIG. 3B and FIG. 3C show the driving state of the present invention.

  In FIG. 3 (a), only the display or recording frame is driven, whereas in the present invention, in FIG. 3 (b), a flicker detection frame is inserted between the frames for moving image shooting or EVF display. To do.

  As a result, the recording frame is not subject to various restrictions normally associated with flicker detection.

  Specifically, in normal flicker detection, when detecting flicker by a 60 Hz power supply, the exposure time is set to a value other than a multiple of 1/120 s. Similarly, when detecting flicker by a power source of 50 Hz, the brightness of the screen can be restricted, for example, by setting the exposure time to other than a multiple of 1/100 s.

  Further, when there is no cause of flicker, FIG. 3B using a normal rolling shutter is advantageous in terms of noise. Therefore, when the flicker is smaller than a predetermined amount due to the flicker determination during the driving as shown in FIG. 3C, the driving is switched to FIG.

  Next, the flicker detection frame will be described in more detail.

  The flicker detection frame is constituted by reading twice.

  For the sake of simplicity, the first exposure time is set to 1/100 sec, and immediately after that, the second reading is performed at an exposure time of 1/120 sec. However, this order may be reversed.

  FIG. 4 is an explanatory diagram of a flicker detection method having a mechanism for measuring a luminance amount. FIG. 4A shows a configuration of a flicker detection frame, and FIGS. 4B and 4C show flickers appearing on the screen. It shows the change in brightness. In FIG. 4, the total number of flicker detection frames is 32, but this number is an example and is not limited.

  Next, extraction of flicker components will be described.

  By calculating the difference between each data of the flicker detection frame obtained by the first exposure and each data of the flicker detection frame obtained by the second exposure, only the flicker component can be extracted.

  FIG. 5 is an explanatory diagram showing the state of this extraction process.

  When flicker is generated by a power source of 50 Hz or 60 Hz in the first exposure shown in FIG. 5A and the second exposure shown in FIG. 5B, the flicker is only on one of the screens. Since the components appear, it is possible to extract only the flicker components by taking the difference.

  However, in order to take the difference between two images with different exposure times, it is necessary to increase the gain of the image with a short exposure time by the difference (6/5 times) in the exposure time so that the exposure amount is the same as that with the long exposure time. There is.

  Alternatively, by reducing the gain of an image having a long exposure time by the difference (5/6 times), only the AC component due to flicker can be extracted.

FIG. 5C shows a difference image, and only a periodic component due to flicker remains.
The luminance at this time changes at a constant cycle as shown in FIG. 5D, and the power supply frequency can be specified from this cycle.

  Next, the flicker frequency is determined from the flicker component extracted as described above.

  First, since it is equally divided by the number of frames of the entire screen, the setting value calculation formula is as follows.

For example, when the number of frames is 32 and the number of effective horizontal lines of the entire screen is 288 lines, the frame interval / width is 9. The unit is a line.

Frame interval / width = 288 ÷ 32 = 9 [line]
Next, how many flicker component peaks (valleys) occur on the screen is calculated.

  The formula for calculating the number of peaks (valleys) is as follows.

  The invalid horizontal line is the number of horizontal lines that do not appear on the screen, that is, the dummy time during which reading is not performed divided by the time for reading one line.

Number of peaks (valleys) generated = read time ÷ flicker cycle ÷ (number of invalid lines + number of valid lines) x number of valid lines For example, when the read time is 1/15 sec, the number of valid lines is 288 lines and the number of invalid lines is Assuming 42 lines, in the case of 50Hz flicker,
1/15 ÷ 1/100 ÷ (288 + 42) × 288 = 5.8. For example, in the case of 60 Hz flicker under the above conditions,
1/15 ÷ 1/120 ÷ (288 + 42) × 288 = 6.9.

  Next, a frame interval at which a flicker peak (valley) occurs is calculated.

  The frame interval in which the peaks (valleys) are generated is as follows.

Frame interval at which peaks (valleys) occur = number of frames / number of peaks (valleys) appearing on the screen If the above example is used as it is, 32 ÷ 5.8 becomes 5.5 in the case of 50 Hz. Tani) occurs every 5 or 6 when viewed in the detection frame.

  In the case of 60 Hz, 32 ÷ 7 is 4.5, and peaks (valleys) are generated every 4 or 5 when viewed in the detection frame.

  Next, a flicker determination method by the flicker determination circuit will be described.

  The discrimination logic is shown below based on the above description.

  In addition, the description which attached | subjected (example) by each following determination is demonstrated using each said example. Discrimination a = It is determined whether or not there is flicker from the number of peaks (valleys).

  (Example) When flicker exists, the number of peaks (valleys) should appear 5-7, so when there are 4-8 peaks (valleys) with some margin (there is flicker) Yes)

  Next, when it is determined that there is a peak and a valley, flicker determination is performed based on the difference value of each signal value.

  For example, when the exposure period is an integer multiple of the flicker cycle under a light source of only a fluorescent lamp, that is, when the remainder when divided by the flicker cycle is 0, the difference value between the signal values of the peaks and valleys Becomes 0, and it is determined that no flicker occurs.

  Next, for example, when the exposure period is 1/10 of the flicker cycle (for example, 1/1000 sec with respect to 1/100 sec of the flicker cycle), the signal value of the peak is about 10 times as large as the valley. .

  When the exposure period is longer than the flicker cycle, the difference between the peak and valley signal values depends on the remaining time when the exposure period is divided by the flicker cycle. And the difference value of the valley becomes large.

  However, even if the remaining time when divided by the flicker cycle is the same, as the exposure period becomes longer, the difference value of the signal value due to flicker, which depends on the remaining time, is relatively smaller than the total signal value. Become.

  That is, whether or not the flicker has occurred is determined based on two values, that is, an average value between the peak and the valley and a difference value between the peak and the valley.

  The determination formula at this time is determined by whether (1) the difference value exceeds a set threshold value.

  For example, when the maximum value of the signal value is 255 LSB, a case where the threshold value of the difference value between the peak portion and the valley portion of the signal value due to flicker is 5 LSB, which is about 2%, will be described.

  According to the detection method, under the light source of 50 Hz to 60 Hz, any number of 4 to 5 or 6 peaks can be seen in the detection frame.

  When the number of peaks or valleys is 4, 5 to 6, the threshold value of the difference value between the peak and valley of the signal value by flicker is obtained from the vertical mapping of the signal value as shown in FIG. .

  Specifically, the maximum value of the plurality of peaks and the minimum value of the valleys are averaged, and the sum value is obtained. If this value is a threshold value and is 5LSB or more, it is determined that flicker has occurred.

  As described above, flicker determination is determined by the number of peaks or valleys in the detection frame and the difference value between the peak and valley signal values.

  Next, a specific correction method when it is determined that flicker has occurred will be described.

  FIG. 6 is a cross-sectional view showing the structure of the PD of the solid-state imaging device and its peripheral portion in this example.

  This solid-state imaging element is obtained by forming each element in a P well region 602 provided on a silicon substrate 601, and FIG. 6 shows a region where a PD 603, an FD 608, a transfer transistor 604, and a reset transistor 605 are formed.

  The P well 602 is a buried PD having a p + region 606 formed on the outermost surface of the silicon substrate 300 and an n region 607 formed below the p + region 606.

  The FD 608 includes an n + region formed on the side of the PD 603 via a transfer gate portion (transfer transistor 604).

  The transfer transistor 604 is obtained by forming an intermediate region between the PD 603 and the FD 608 as a transfer gate portion and forming a transfer electrode made of a polysilicon film on the upper surface of the silicon substrate 601 with a gate insulating film 610 interposed therebetween.

  The reset transistor 605 has a region opposite to the transfer transistor 604 of the FD 608 as a reset gate portion, and a reset electrode made of a polysilicon film is formed on the upper surface of the silicon substrate 300 via a gate insulating film 610. The FD 608 Are discharged to the drain 609.

  The drain 609 is connected to the wiring of the power supply Vdd through a contact or the like (not shown).

  An upper layer stack is provided above each electrode with a gate insulating film 610 interposed therebetween, but the description thereof is omitted.

  FIG. 3C is a timing chart showing an exposure state at the time of driving in which flicker of the solid-state imaging device of this example is suppressed.

  First, the FD 608 is reset and the photoelectrons of the PD 603 are transferred to the FD 608 simultaneously for all the rows.

  Specifically, for example, a pulse is input to the reset wiring of all rows to reset the FD 608 of all pixels, and a pulse is further applied to the transfer wiring of all rows to transfer the photoelectrons of the PD 603 of all pixels to the FD 608.

  Then, although not shown in the figure, the signal of the FD 608 is read line by line.

  Next, immediately after each line is read out, the line is reset, and the first exposure (in this case, 1/100 sec) for flicker detection is started.

  Further, after the first exposure is completed and the charge of the pixel is transferred to the FD 608, the second exposure (in this case, 1/120 sec) with a different exposure time is started.

  At this time, in the flicker detection frame, the exposure start time is shifted for each line, and in-plane flicker is detected under a light source of 50 Hz or 60 Hz that causes flicker.

  Here, since the period of one frame is determined to be a certain fixed period such as 1/30 second, after the second exposure for flicker detection, the time is adjusted by a dummy output or the like.

  In this example, the exposure order is a recording frame, flicker detection 1/100 sec exposure, and flicker detection 1/120 sec exposure. However, the order is not limited to this.

  FIG. 7 is an explanatory diagram showing potential transition at the time of charge reading in such a solid-state imaging device, and shows a positive potential in the downward direction.

  FIG. 7A shows the potential immediately after all pixels are reset, and photocharges are gradually accumulated in the PD 603.

  In FIG. 7B, the transfer transistor 604 is turned on to set the channel voltage of the transfer gate to Va, and the photocharge of the PD 603 is moved to the FD 608.

  FIG. 7C shows the state of the non-exposure time after transfer, and photocharge is gradually accumulated in the PD 603. At this time, the signal value of the pixel corresponding to the amount of charge moved to the FD 608 can be obtained as a voltage.

  FIG. 7D shows a state in which the PD 603 and the FD 608 are reset, and charges can be discharged by applying a voltage to the transfer gate and the reset gate. After discharging the charge, the gate voltage is turned off to return to the state shown in FIG.

  However, the flicker suppression method by such batch exposure can surely eliminate the in-plane flicker, but the dark charge caused by leaving the signal charge in the FD for a long time and the deterioration of image quality due to charge recombination. There is no escape.

  Therefore, even after it is determined that flicker has occurred and the drive mode has been changed, flicker detection continues, and if it is determined that there is no flicker, the normal drive mode is restored to minimize image quality degradation. It can be suppressed to the limit.

  FIG. 8 shows a flowchart of the operation of the present invention.

  After starting the moving image shooting, two images are shot between the moving image shooting or EVF display frame and the next frame (801).

  The brightness of the two images is matched by increasing the gain of one image, and then the difference is taken to extract the flicker component (802).

  If a frequency component exists in the luminance in the vertical direction of the difference file and the frequency is considered to be caused by flicker, it is determined that flicker has occurred (803).

  If flicker occurs, change to a drive mode that transfers all pixels to the FD at once.

  If not, the operation is performed in the normal rolling shutter shooting drive mode (804).

  Return to 801 and repeat until the switch is turned off.

  In this way, even after it is determined that flicker has occurred and the drive mode has been changed, flicker detection is continued. If it is determined that there is no flicker, the image quality is improved by returning to the normal drive mode. Degradation can be minimized.

  The content of this operation is stored as a program code in an arbitrary storage medium (not shown) in the digital camera, and is read and executed by a CPU or the like in the digital camera.

  As described above, the object of the present invention is to provide a system or apparatus with a storage medium storing software program codes for realizing the functions of the embodiments, and the system or apparatus computer (or CPU or MPU) stores the storage medium. It is also achieved by reading and executing the program code stored on the medium.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.

  As a storage medium for supplying such a program code, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM Etc. can be used.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) running on the computer based on the instruction of the program code Includes a case where part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.

  Furthermore, after the program code read from the storage medium is written in the memory provided in the function expansion board inserted into the computer or the function expansion unit connected to the computer, the function is determined based on the instruction of the program code. This includes a case where the CPU or the like provided in the expansion board or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

FIG. 2 is a schematic diagram of a solid-state imaging device according to Embodiment 1. 1 is a schematic diagram of a pixel of a solid-state image sensor in Embodiment 1. FIG. A moving image shooting method when performing conventional rolling shutter and flicker detection according to the present invention. The flicker detection method in the present invention. The flicker discrimination method in the present invention. Cross-sectional structure of CMOS. CMOS charge transfer principle. The imaging | photography flowchart of this invention. Rolling exposure and batch exposure in CMOS.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Lens 102 Diaphragm 103 Mechanical shutter 104 Solid-state image sensor 105 Image sensor drive circuit 106 CDS circuit 107 AGC circuit 108 Clamp circuit 109 AD conversion circuit 110 Video processing circuit 111 Video signal processing circuit 112 Photometry circuit 113 Timing pulse generation circuit 114 CPU
115 Sensitivity and Exposure Control Unit 116 Exposure Control Circuit 117 OB Integration Circuit 118 OB Level Block Comparison Circuit 201 Photodiode 202 Amplification Transistor 203 Floating Diffusion (FD)
204 Transfer Transistor 205 Vertical Selection Transistor 206 Reset Transistor 207 Vertical Shift Register 208 Horizontal Address Line 209 Reset Line 210 Vertical Signal Line 211 Load Transistor 212 Horizontal Shift Register 213 Horizontal Signal Line 601 Si Substrate 602 P Well Region 603 Photodiode (PD)
604 Transfer transistor 605 Reset transistor 606 p + region 607 n region 608 Floating diffusion (FD)
609 Reset drain 610 Gate insulating film

Claims (10)

  A two-dimensional array of optical signals is converted into an electrical signal, it has a large number of pixels, sequentially scans every pixel row to reset the signal, moving image shooting or EVF display means, and irradiation of the subject Flicker detection means for detecting the amount of flicker caused by a periodic change in the amount of light being flickered, flicker determination means for judging whether the amount of flicker obtained by the flicker detection is a predetermined value or more, and electric information Collective resetting means that discharges charges from the photodiode portion at the same time for pixels in a predetermined area of the image sensor, and a floating region from the photodiode section for pixels in the predetermined area of the image sensor simultaneously. Flicker detection is performed by an imaging apparatus having batch FD transfer means for transferring charges to the diffusion portion, and the If Tsu mosquito is determined to have occurred, the imaging device and performs the bulk reset at frame for moving image shooting or EVF display, the batch FD transfer.   2. The imaging apparatus according to claim 1, wherein the flicker detection means uses two images taken at shutter speeds n / 100 sec and m / 120 sec, where n and m are arbitrary integers.   The flicker determination unit according to claim 1 detects a luminance value of a plurality of common areas of two images taken at a shutter speed of n / 100 sec and m / 120 sec, and whether the difference value exceeds a certain value. An image pickup apparatus that determines whether or not flicker has occurred depending on whether or not flicker has occurred.   2. The imaging apparatus according to claim 1, wherein the flicker detection frame is exposed by a focal plane shutter.   2. The image pickup apparatus according to claim 1, wherein the flicker detection means performs exposure of a flicker detection frame separately from a moving image shooting or EVF display frame.   The flicker detection frame according to claim 2 is such that exposure at a shutter speed of n / 100 sec is performed first before a moving image shooting or EVF display frame, and a moving image shooting or EVF display frame is sandwiched between the shutter speed. An imaging apparatus that performs n / 120 sec exposure.   The flicker detection frame according to claim 2 is a shutter speed n / 120 sec exposure first before a moving image shooting or EVF display frame, and a moving image shooting or EVF display frame is sandwiched between the shutter speed. An imaging apparatus that performs n / 100 sec exposure.   The flicker detection frame according to claim 2 is subjected to exposure at a shutter speed of n / 120 sec before a moving image shooting or EVF display frame, and exposure at a shutter speed of n / 100 sec immediately after or immediately before. An imaging apparatus characterized by that.   The flicker detection frame according to claim 2 is such that exposure at a shutter speed of n / 100 sec is performed first after a moving image shooting or EVF display frame, and exposure at a shutter speed of n / 120 sec is performed immediately after or immediately before. An imaging apparatus characterized by the above.   4. An imaging apparatus according to claim 2, wherein the values of n and m are 1.

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