JP2017126921A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide means of improving detection precision of a period and a phase of a flicker when a subject moves at high speed during flicker-free photography.SOLUTION: An imaging apparatus comprises: a solid-state imaging element A and a solid-state imaging element B having a light reception part for generating and accumulating optical charges according to a light reception quantity; means of calculating a first accumulation time; means of generating a first accumulation start timing signal and a read start timing signal using the first accumulation time; means of calculating a second accumulation time longer than the first accumulation time; means of generating a second accumulation start timing signal and a read timing signal such that the first accumulation time is included in the second accumulation time, and controlling accumulation and reading of optical charges of the solid-state imaging element B; detecting means of detecting timing where variation in light quantity due to a flicker is small on the basis of an image obtained from the solid-state imaging element A; and photographing means of photographing a still image at the detected timing where the variation in light quantity due to the flicker is small.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging apparatus typified by a digital camera, and more particularly to an improvement in flicker detection accuracy in shooting that reduces exposure unevenness due to a change in the amount of external light (generally called flicker) that occurs during shooting.

  Conventionally, under an artificial light source including flicker, the amount of light is insufficient and photographing at a high shutter speed cannot be performed, so that the problem of uneven exposure due to flicker has not occurred.

  However, in recent years, with the increase in ISO of digital cameras, an appropriate exposure level can be obtained at the time of high-speed shutter photography even under an artificial light source including such flicker, so that it is actually used. .

  However, when high-speed shutter shooting is performed under a flicker light source, the exposure for each frame varies in continuous shooting due to a change in the amount of external light.

  In order to deal with such a problem, there is a control in which exposure variation for each frame does not occur by matching the timing when the shutter travels with the timing at which the change in the amount of flicker light is small.

  In addition, in such a flicker light source, Patent Document 1 discloses that at the time of still image shooting from live view (hereinafter referred to as LV), the flicker cycle and peak timing are detected, and a still image is shot at the peak timing. A technique for reducing exposure unevenness due to flicker is disclosed.

Japanese Patent Laying-Open No. 2015-08917

  However, in the conventional technique disclosed in Patent Document 1 described above, two images to be compared to detect the flicker period and phase are taken at different times, so that the subject moves at high speed on the screen. When the deviation occurs, the flicker period and the phase detection accuracy are lowered.

  Accordingly, an object of the present invention is to provide means capable of improving flicker period and phase detection accuracy when a subject moves at high speed in a technique for reducing exposure unevenness due to flicker. .

In order to achieve the above object, a photographing apparatus according to the present invention includes:
A solid-state imaging device A and a solid-state imaging device B each having a light-receiving unit that generates and accumulates photocharges according to the amount of received light, the plurality of light-receiving units being arranged two-dimensionally, and means for calculating a first accumulation time And means for generating a first accumulation start timing signal and a read start timing signal using the first accumulation time, and controlling the accumulation and reading of the photocharges of the solid-state imaging device A, and the first accumulation time Means for calculating a longer second accumulation time, and a second accumulation start timing signal and a read start timing signal for including the first accumulation time in the second accumulation time to generate light of the solid-state image sensor B Means for controlling charge accumulation and reading, detection means for detecting a timing at which the light quantity change of the flicker is small based on the image A obtained from the solid-state imaging device A, and a light quantity change by the detected flicker is small. Characterized in that it comprises an imaging means for performing still image shooting in timing.

  According to the present invention, in a technique for detecting flicker cycle and peak timing during still image shooting from LV and reducing exposure unevenness due to flicker, detection of flicker cycle and phase when a subject moves at high speed. Means for improving accuracy can be provided.

It is a block diagram of a camera concerning an embodiment of the present invention. It is an arrangement plan of an interchangeable lens, a camera, and each block concerning an embodiment of the present invention. It is a figure which shows the image pick-up element used for the imaging device which concerns on embodiment of this invention. 4 is a timing chart of a slit rolling shutter driving method according to an embodiment of the present invention. 3 is a timing chart of an electronic front curtain shutter driving method according to an embodiment of the present invention. It is the figure which showed the picked-up image at the time of image | photographing at the timing when the light quantity of the flicker which concerns on embodiment of this invention is high. It is the figure which showed the picked-up image at the time of image | photographing at the timing when the light quantity of the flicker concerning embodiment of this invention is low. It is the figure which showed the light quantity change of the flicker which concerns on 1st embodiment of this invention, and the accumulation | storage timing of the image image | photographed at that time. It is the figure which showed the light quantity change of the flicker which concerns on embodiment of this invention, and the image image | photographed at that time. It is the image which showed the calculation for extracting the flicker component by flicker from the image with a flicker by flicker and the image without a flicker concerning an embodiment of the present invention. It is the figure which showed the procedure for detecting the timing when the period and light quantity of flicker which concern on embodiment of this invention become the maximum. It is the figure which showed the relationship between the pixel count of two fixed image sensors which concern on 2nd embodiment of this invention, the amount of thinning-out, and read-out time. It is the figure which showed the light quantity change of the flicker which concerns on 3rd embodiment of this invention, and the accumulation | storage timing of the image image | photographed at that time. It is the figure which showed the light quantity change of the flicker which concerns on 4th embodiment of this invention, and the accumulation | storage timing of the image image | photographed at that time. It is the figure which showed the light quantity change of the flicker concerning the 5th embodiment of this invention, and the accumulation | storage timing of the image image | photographed at that time. It is the figure which showed the light quantity change of the flicker concerning the 6th embodiment of this invention, and the accumulation | storage timing of the image image | photographed at that time. It is the figure which showed the light quantity change of the flicker concerning the 7th embodiment of this invention, and the accumulation | storage timing of the image image | photographed at that time.

  Embodiments of the present invention will be described below with reference to the drawings. Here, in the embodiment of the present invention, an example in which a digital single-lens reflex camera is applied as an imaging apparatus according to the present invention will be described.

(First embodiment)
FIG. 1 is a block diagram of Example 1 showing a schematic configuration of a digital single-lens reflex camera (imaging device) according to an embodiment of the present invention, in which 100 is a camera body and 200 is an interchangeable lens. FIG. 2 is a diagram showing the actual arrangement of the blocks shown in FIG. 1 in the camera.

  1 and 2, reference numeral 101 denotes an overall control / arithmetic unit that performs overall control of various arithmetic processes and the entire digital single-lens reflex camera 100 and the interchangeable lens 200 as the imaging apparatus.

  Reference numeral 200 denotes an interchangeable lens for a digital single-lens reflex camera, 202 denotes an imaging lens that forms an optical image of a subject on the imaging device A106 and the imaging device B116, and 203 drives the photographing lens so that the focus is in focus. A driving device 204 is a diaphragm mechanism that controls the amount of light reflected from the subject image through the lens, and 205 is a diaphragm driving device that drives the diaphragm mechanism.

  The interchangeable lens 200 for photographing and the digital single-lens reflex camera 100 can be removed for replacement, and the interchangeable lens 200 and the digital single-lens reflex camera 100 communicate for information exchange. As for the communication at this time, with respect to the digital single-lens reflex camera 100, the overall control / calculation unit 101 and the lens control unit 201 communicate to manage transmission / reception.

  Reference numeral 100 denotes a digital single-lens reflex camera which is a main body of the image pickup apparatus, and reference numeral 102 denotes a half mirror that splits an optical image that has passed through the taking lens 202 and guides it to the image pickup element A 106 and the image pickup element B 116.

  Reference numeral 104 denotes a shutter mechanism having a shutter plane corresponding to a focal plane type front curtain / rear curtain used in a so-called single-lens reflex camera, and controls the exposure time of an optical image that has passed through the imaging lens 202 and blocks light.

  Reference numeral 105 denotes a shutter driving device that drives the shutter mechanism 104.

  Reference numeral 106 denotes a (solid-state) image sensor A for capturing an optical image of a subject imaged by the image pickup lens 202 as an image signal. The image sensor A106 of the present embodiment is formed by a two-dimensional XY address scanning type such as a CMOS sensor, for example. The image sensor A106 is mainly intended to capture still images.

  Reference numeral 107 denotes various correction processes such as an amplification process of an image signal output from the image sensor A106, an A / D conversion process for converting from analog to digital, and a defect correction for image data after A / D conversion, or An imaging signal processing unit A that performs compression processing for compressing image data.

  Reference numeral 108 denotes a timing generator A that outputs various timing signals to the image sensor A106 and the image signal processor A107.

  109 temporarily stores image data and the like processed by the image signal processing unit A107, and permanently stores various adjustment values and programs for executing various controls by the overall control / arithmetic unit 101. It is a memory part for.

  Reference numeral 110 denotes a recording medium control interface (I / F) unit for performing recording processing of image data and the like on the recording medium 111 or reading processing of image data and the like from the recording medium 111.

  A detachable recording medium 111 includes a semiconductor memory or the like for recording various data such as image data.

  Reference numeral 112 denotes a drive unit that drives a display unit 113 that displays captured still images, moving images, and the like.

  An external interface 114 exchanges information such as image signals and control signals with an external device for the computer 115.

  Reference numeral 116 denotes a (solid-state) imaging element B for taking in an optical image of a subject formed by the imaging lens 202 as an image signal. The image sensor B116 of this embodiment is formed by a two-dimensional XY address scanning type like a CMOS sensor, like the image sensor A106 of this embodiment. Further, the image sensor B116 of the present embodiment has the same number of pixels as the image sensor A106, and has the same readout time. The image sensor B116 is mainly intended for capturing moving images and LVs.

  Reference numeral 117 denotes various correction processes such as an amplification process of an image signal output from the image sensor B116, an A / D conversion process for converting from analog to digital, and a defect correction for image data after A / D conversion, or An imaging signal processing unit B that performs compression processing for compressing image data.

  Reference numeral 118 denotes a timing generator B that outputs various timing signals to the image sensor B116 and the image signal processor B117.

  Reference numeral 121 denotes a distance measuring unit using a phase difference method, which acquires two pairs of images whose phases change according to the defocus amount of the subject by the light beam that has passed through the half mirror 102. The defocus amount of the subject is calculated from the shift amount of the two images, and the imaging lens 202 is moved.

  Reference numeral 120 denotes a distance measuring unit driving device that drives the phase difference distance measuring unit 121.

  FIG. 3 is a schematic configuration diagram of a solid-state imaging device included in the imaging apparatus. This figure shows the configuration of a solid-state image sensor A106 and a solid-state image sensor B116 that employ a two-dimensional scanning method.

  Reference numeral 301 denotes one pixel which is a unit of driving.

  Reference numeral 302 denotes a photodiode that converts light into electric charges (hereinafter, this photodiode is referred to as “PD”).

  Reference numeral 306 denotes a floating diffusion (hereinafter, this floating diffusion is referred to as “FD”), which is a region for temporarily accumulating charges.

  A transfer switch 303 transfers charges generated in the PD 302 to the FD 306 by the transfer pulse φTX.

  Reference numeral 307 denotes an amplification MOS amplifier that functions as a source follower.

  Reference numeral 308 denotes a selection switch that selects a pixel by the selection pulse φSELV.

  Reference numeral 309 denotes a reset switch that removes charges accumulated in the FD 306 by the reset pulse φRES.

  Reference numeral 311 denotes a constant current source serving as a load of the amplification MOS amplifier 307.

  Reference numeral 315 denotes a pixel that is stored in the FD 306 of the pixel selected by the selection switch 308 into a voltage by charge / voltage conversion by the amplification MOS amplifier 307 and the constant current source 311, and then the pixel data via the signal output line 310. As a readout circuit.

  Reference numeral 312 denotes a selection switch that selects pixel data (pixel signal) read by the reading circuit 315 and is driven by the horizontal scanning circuit 316. The pixel data selected by the horizontal scanning circuit 316 is amplified by the output amplifier 313 and output from the solid-state image sensor A106.

  Reference numeral 314 denotes a vertical scanning circuit for selecting the switches 303, 308, and 309. Here, in each of φTX, φRES, and φSELV, the nth scan line selected by the vertical scanning circuit 314 is φTXn, φRESn, φSELVn, and the (n + 1) th scan line is φTXn + 1, φRESn + 1, φSELVn + 1. FIG. 1 shows from the nth scan line to the (n + 6) th scan line for convenience. The FD 306, the amplification MOS amplifier 307 and the constant current source 311 constitute a “floating diffusion amplifier”.

  Next, a slit rolling shutter operation for controlling the exposure amounts of the solid-state image sensor A106 and the solid-state image sensor B116 will be described with reference to FIG.

  FIG. 4 is a sequence diagram showing the operation of a solid-state imaging device that reads out pixel data by controlling the exposure amount to be appropriate using an electronic front curtain shutter and an electronic rear curtain shutter during slit rolling shutter photography. It is.

  In the operation of the electronic front curtain shutter, first, a pulse is applied to φRESn and φTXn from time t401 to t402 on the nth line, and the transfer switch 303 and the reset switch 309 are turned on. As a result, unnecessary charges accumulated in the PD 302 and FD 306 of the nth line are removed, and the reset operation is performed.

  Subsequently, at time t402, the application of pulses to φRESn and φTXn is released, the transfer switch 303 and the reset switch 309 are turned off, and the operation of accumulating the charge generated in the PD 302 of the nth line is started.

  Since the n + 1 line and the n + 2 line are not used as an image, no processing is performed here.

  In this embodiment, processing is not performed for the n + 1 line and the n + 2 line, but if it is considered that charges accumulate in the PD and leak to the surrounding pixels, the φRESn and φTXn of the n + 1 line and the n + 2 line are turned on. However, it is necessary to always reset the charge of the PD.

  At time t403, the accumulation operation for the (n + 3) th line is started as at time t402, and at time t404, the accumulation operation for the (n + 6) th line is started.

  In this way, an electronic front curtain shutter operation is realized by sequentially releasing the line reset at regular intervals and starting the charge accumulation operation.

  Here, returning to the n-th line, a pulse is applied to φTXn from time t 405 to time t 406, the transfer switch 303 is turned on, and a transfer operation for transferring the charge accumulated in the PD 302 to the FD 306 is performed.

  Subsequent to the end of the transfer operation of the nth line, a pulse is applied to φSELVn and the selection switch 308 is turned on from time t406 to t407, whereby the charge held in the FD 306 is converted into voltage, and pixel data (pixel Signal) is output to the reading circuit 315.

  The pixel data temporarily held by the readout circuit 315 is sequentially output from the time t407 by the horizontal scanning circuit 316. At time t408, reading of pixel data from the pixels on the nth line is completed.

  In the (n + 3) th line, between time t408 and t409, a pulse is applied to φTXn + 3, the transfer switch 303 is turned on, and a transfer operation for transferring the charge accumulated in the PD 302 to the FD 306 is performed.

  Subsequent to the end of the transfer operation of the n + 3 line, between time t409 and t410, a pulse is applied to φSELVn + 3 and the selection switch 308 is turned on, whereby the charge held in the FD 306 is converted into voltage and read as pixel data. It is output to the circuit 315. The pixel data temporarily held by the readout circuit 315 is sequentially output from the time t410 by the horizontal scanning circuit 316. At time t411, reading of pixel data from the pixels in the (n + 3) th line is completed.

  In this way, an electronic rear curtain shutter is realized by transferring and reading out charges at regular intervals.

  The time from PD reset of each line to transfer is the exposure time of each pixel.

  Next, the electronic front curtain shutter operation for controlling the exposure amount of the solid-state imaging device A 106 using the electronic front curtain shutter and the mechanical rear curtain shutter will be described with reference to FIG.

  FIG. 5 is a sequence showing the operation of a solid-state image sensor that reads out pixel data by controlling the exposure amount to be appropriate using an electronic front curtain shutter and a mechanical rear curtain shutter during electronic front curtain shutter photography. FIG.

  In the operation of the electronic front curtain shutter, on the n-th line, φRESn and φTXn are first turned on to reset PD and FD. As a result, the transfer switch 303 and the reset switch 309 are turned on. As a result, unnecessary charges accumulated in the PD 302 and FD 306 of the nth line are removed, and the reset operation is performed.

  Subsequently, at time t502, φRESn and φTXn are released, the transfer switch 303 and the reset switch 309 are turned off, and the accumulation operation of the charge generated in the PD 302 of the nth line is started.

  Similarly, the accumulation operation of the (n + 1) th line starts at time t503, the accumulation operation of the (n + 2) th line at time t504, the accumulation operation of the (n + 3) th line at time t505, the accumulation operation of the (n + 4) th line at time t508, and the accumulation operation at the time t510. The accumulation operation for the n + 5 line, and the accumulation operation for the (n + 6) th line starts at time t513.

  In this way, the electronic front curtain shutter operation is realized by sequentially releasing the line reset and starting the charge accumulation operation.

  Following this, the rear curtain shutter of the mechanism travels.

  The exposure time is between the electronic front curtain shutter and the mechanical rear curtain shutter, and the reset timing of the electronic front curtain shutter is controlled so that the exposure amount of each line is appropriate.

  Here, returning to the n-th line, after the trailing shutter has finished running, a pulse is applied to φTXn from time t515 to t516, the transfer switch 303 is turned on, and the charge accumulated in the PD 302 is transferred to the FD 306. A transfer operation is performed.

  Subsequent to the end of the transfer operation of the nth line, a pulse is applied to φSELVn and the selection switch 308 is turned on from time t516 to t517, whereby the charge held in the FD 306 is converted into voltage, and pixel data (pixel Signal) is output to the reading circuit 315.

  The pixel data temporarily held in the readout circuit 315 is sequentially output from the time t517 by the horizontal scanning circuit 316. At time t519, reading of pixel data from the pixels on the nth line is completed.

  In the (n + 1) th line, during time t519 to t521, a pulse is applied to φTXn + 1, the transfer switch 303 is turned on, and a transfer operation for transferring the charge accumulated in the PD 302 to the FD 306 is performed.

  Subsequent to the end of the transfer operation of the (n + 1) th line, between time t521 and t522, a pulse is applied to φSELVn + 1 and the selection switch 308 is turned on, whereby the charge held in the FD 306 is converted into voltage and read as pixel data. It is output to the circuit 315. Pixel data temporarily held in the readout circuit 315 is sequentially output from the time t522 by the horizontal scanning circuit 316. At time t523, reading of pixel data from the pixels in the (n + 1) th line is completed.

  6 and 7 show an example of a still image photographed under a flicker light source, a change in the light amount of the flicker light source, a timing at which the shutter is released, and a still image image photographed at that timing.

  In FIG. 5, the shutter release timing moves from the top to the bottom in accordance with the scanning direction of the solid-state imaging device. However, in FIGS. 6 and 7, the actual shutter travels from the bottom to the top with respect to the camera. It moves from bottom to top according to the direction. 5 and 6 and 7 show the same operation.

  In recent years, digital cameras have become more and more sensitive, and when shooting with a high-speed shutter under an artificial light source such as a gymnasium, even with an environment where proper exposure could not be obtained, a high-speed shutter such as 1/4000 seconds or 1/8000 seconds was used. It is now possible to obtain an appropriate exposure.

  As a result, for example, when shooting with a high-speed shutter under a light source of varying light quantity such as a fluorescent lamp, a still image with a larger exposure amount is shot when the shutter travels at a timing when the light quantity is large as shown in FIG. As shown in FIG. 7, when the shutter travels at a timing when the amount of light is small, a still image with an underexposure amount that is insufficient is taken.

  Since the timing at which the shutter travels is so fast that humans cannot adjust it intentionally, actually, still images with different exposure amounts are photographed as Kilimra.

  FIG. 8 shows the sequence in the present embodiment by sensor accumulation and readout. The dotted line is the sensor reset, the solid line is read out, the horizontal direction from the dotted line to the solid line is the accumulation time of the image, and the vertical direction is the vertical position of the image. The solid-state image sensor B116 acquires an image accumulated in a time sufficiently longer than the flicker cycle. This image is used as an LV display. Here, when the trigger signal for still image shooting becomes Low, the solid-state imaging device A 106 acquires A in an accumulation time shorter than the flicker cycle. This A is not used as an LV display.

  The calculation shown in FIGS. 10 and 11 (details will be described later) is performed based on the images acquired by A and B, and the timing at which the light amount of flicker reaches a peak is obtained. At the timing at which the light amount reaches a peak. The timing generator A108 controls the transfer switch and the reset switch so that the electronic front curtain shutter travel (shown in FIG. 5) starts.

  As a feature of the present invention, the readout time and the number of pixels of the solid-state image sensor A106 are the same as those of the solid-state image sensor B116. In order to increase the degree of coincidence between the image A and the image B, the accumulation time of the solid-state image sensor B116 is restricted so as to include the accumulation time of the solid-state image sensor A106.

  Here, it is shown that the time during which the shutter travels at the time of still image shooting is long, but this is widened for the purpose of illustration.

  Since the actual travel time is very short compared to the flicker cycle, the travel of the shutter is completed during the peak light amount.

  The same applies to the following drawings.

  FIG. 9 shows an image of the solid-state image sensor A and an image of the solid-state image sensor B taken in the sequence of FIG. Since the solid-state image sensor B accumulates in a time sufficiently longer than the flicker cycle, an image with reduced exposure unevenness due to flicker can be obtained. In this embodiment, this image is acquired and displayed as a normal LV image. Further, since the solid-state imaging device A accumulates in a time shorter than the flicker cycle, an image in which uneven exposure due to flicker occurs can be obtained. This image is not displayed in LV.

  FIG. 10 is a diagram showing a calculation process for the image acquired in FIG.

  FIG. 10A shows an image shot so as to cause exposure unevenness due to flicker, and FIG. 10B shows an image shot so as to reduce exposure unevenness. The two images are divided and FIG. get. In FIG. 10C, by dividing an image in which exposure unevenness due to flicker is generated by an image in which exposure unevenness due to flicker is reduced, only the exposure unevenness component due to flicker can be extracted. However, as shown in FIG. 10-A, an image in which exposure unevenness due to flicker has occurred is taken with a short exposure time in order to make exposure unevenness due to flicker easy to occur, and conversely, exposure unevenness due to flicker as shown in FIG. 10-B. Since an image with reduced exposure is taken with an exposure time that is an integral multiple of the flicker cycle or longer so that exposure unevenness due to flicker does not occur, there will be a difference in exposure amount.

  Therefore, it is necessary to adjust the exposure amount by adjusting the gain at the time of image acquisition or by applying gain to the acquired image. In addition, when the position of the subject moves between the images A and B or the direction of the camera changes, the image screen is divided and the degree of coincidence between the images is calculated to align the images. It is necessary to divide after doing.

  The timing at which the amount of flicker light from VD peaks is found based on the image C of only the exposure unevenness component by flicker obtained in this way. Also, the flicker cycle is obtained based on this image.

  FIG. 11 is a diagram showing the light amount change (solid line) in the vertical direction shown in FIG. 10-C and the adjacent difference (broken line) of this light amount change data, and shows a method of detecting Peak in FIG. 10-C. It is a figure.

  Here, when the value of the broken line is “0”, the maximum value or the minimum value of the light amount change is indicated. In particular, the “0” value when the broken line value changes from positive to negative is a local maximum value. If this Peak is known as the number of lines on the screen, the time from VD to Peak can be obtained based on the HD cycle. Further, it is possible to obtain the flicker cycle by obtaining the time from “0” to “0” of the broken line. From the Peak time obtained here and the flicker cycle, it is possible to determine when the next shooting timing should be set.

  As a unique effect of this embodiment, by reading out images A and B using two sensors in this way, the degree of coincidence between images A and B increases, and the accuracy of detecting the flicker period and phase is improved. It becomes possible to improve. Further, since the degree of coincidence of the images is increased, it is not necessary to calculate the degree of coincidence of the image and the alignment process when performing the calculation shown in FIG. 10, shorten the time for calculating the shutter travel timing, and shorten the release time lag. It becomes possible to do.

(Second embodiment)
In the first embodiment, it is assumed that the number of pixels and the readout time of the solid-state image sensor A106 and the solid-state image sensor B116 are the same. However, since the solid-state image sensor A106 mainly captures still images, and the solid-state image sensor B116 mainly captures LV and moving images, the solid-state image sensor B116 has a smaller number of pixels and a shorter readout time than the solid-state image sensor A106. There is. In the present embodiment, means for obtaining the same effect in such a case will be described.

  As shown in FIG. 12, the readout time of the solid-state image sensor A106 is longer than that of the solid-state image sensor B116, but by thinning out the number of pixels to be read out in the horizontal direction and / or the vertical direction (or both), The time for reading an image with reduced exposure unevenness due to flicker and the time for reading an image with uneven exposure due to flicker of the solid-state image sensor A106 are made the same. Other operations are the same as those in the first embodiment. Similar to the description of FIG. 8, a restriction is provided so that the accumulation time of the image A is included in the accumulation time of the image B.

  As a unique effect of the present embodiment, when the number of pixels of the solid-state image sensor B116 and the number of pixels of the solid-state image sensor A106 are different, it is possible to improve the accuracy of detecting the flicker cycle and phase. Also, the release time lag can be shortened.

(Third embodiment)
In the second embodiment, it is assumed that the readout time is the same as a result of thinning out the number of pixels read out by the solid-state imaging device A106. However, there are cases where the readout time of the thinned result is not the same. In the present embodiment, means and a sequence for solving this problem will be described.

  The number of pixels to be read by the solid-state image sensor A106 is thinned out so that the read time of the solid-state image sensor A106 is shorter than the time to read by the solid-state image sensor B116. This makes it easy to include the accumulation time of the solid-state image sensor A106 in the accumulation time of the solid-state image sensor B116. Other operations are the same as those in the second embodiment.

  FIG. 13 shows a sequence when the readout time of the solid-state image sensor A106 is shorter than the readout time of the solid-state image sensor B116. Similar to the description of FIG. 8, a restriction is provided so that the accumulation time of the image A is included in the accumulation time of the image B.

  As a unique effect of the present embodiment, it is possible to improve the accuracy of detecting the flicker period and phase when the readout time is not the same even if the number of readout pixels is thinned out. Also, the release time lag can be shortened.

(Fourth embodiment)
In the first embodiment, the timing at which the solid-state imaging device A 106 reads the image A is immediately after the trigger signal for still image shooting becomes Low. However, since the solid-state image sensor B116 operates regardless of the trigger signal for still image shooting, the accumulation time of the solid-state image sensor A106 may not be included in the accumulation time of the solid-state image sensor B116. In the present embodiment, means and a sequence for solving this problem will be described.

  The read start timing of the solid-state image sensor A106 and the read start timing of the solid-state image sensor B116 are controlled by the timing generator A108 and the timing generator B118, respectively. The overall control / arithmetic unit 101 determines the timing at which the timing generator A 108 and the timing generator B 118 output the control signal. The overall control / calculation unit 101 performs control so that the control signal for the read start timing of the image A and the control signal for the read start timing of the image B are output simultaneously. Other operations are the same as those in the first embodiment.

  FIG. 14 is a sequence when the control signal for the read start timing of the image A and the control signal for the read start timing of the image B are output simultaneously. By controlling so that the read start timing control signal for image A and the read start timing control signal for image B are output simultaneously, the accumulation time of solid-state image sensor A106 is included in the accumulation time of solid-state image sensor B116. I understand that.

  As an inherent effect of the present embodiment, the storage time of the solid-state image sensor A106 is easily included in the storage time of the solid-state image sensor B116.

(Fifth embodiment)
In the fourth embodiment, the solid-state imaging device A106 reads the image A only once after the trigger signal for the still image shooting becomes Low, but in this embodiment, the solid-state imaging device A106 performs the trigger for the still image shooting. Reading of image A is repeated before the signal becomes low. Other operations are the same as those in the fourth embodiment.

  FIG. 15 shows a sequence in the case where the solid-state imaging device A106 repeats reading of the image A before the trigger signal for still image shooting becomes Low. Further, by performing the calculation shown in FIGS. 10 and 11 every time the image A and the image B are read, the flicker cycle and phase can be detected before the still image shooting trigger signal becomes Low. . After the still image shooting trigger signal becomes Low, the last detection result is used to determine the still image shooting timing.

  As a unique effect of the present embodiment, the release time lag can be further shortened.

(Sixth embodiment)
In the fifth embodiment, the solid-state imaging device A106 reads the image A every time at the same timing as the reading of the solid-state imaging device B116, but in this embodiment, the solid-state imaging device A106 reads intermittently. Other operations are the same as those in the fifth embodiment.

  FIG. 16 shows a sequence for intermittent reading.

  As a unique effect of the present embodiment, power consumption can be suppressed as compared with the operation of the fifth embodiment.

(Seventh embodiment)
In the first embodiment, it is assumed that the peak of the flicker light amount is included a plurality of times during the readout time of the solid-state imaging device A106. However, the flicker light quantity peak may not be included a plurality of times, for example, by increasing the frame rate of the LV and increasing the readout time of the solid-state image sensor A106 and the solid-state image sensor B116. In the present embodiment, means and a sequence for solving this problem will be described.

  In order to increase the frame rate of the LV, if the read time of the solid-state image sensor A106 and the solid-state image sensor B116 is increased, the flicker cycle cannot be included a plurality of times within the read time of the solid-state image sensor A106. The number of peaks in the image having only the exposure unevenness component due to flicker is reduced, and it becomes impossible to find the timing at which the amount of flicker light reaches the peak from the calculations shown in FIGS. In order to solve this problem, in order to include the flicker cycle a plurality of times during the readout period of the solid-state imaging device A106, the transfer switch and reset switch for each row shown in FIG. By controlling so that the eye-on timing interval is widened, the readout time of the solid-state image sensor A106 is lengthened. Other operations are the same as those in the first embodiment.

  FIG. 17 shows a sequence when the frame rate of the LV is high. It can be seen that the frame rate of the LV is increased and the readout time of the solid-state image sensor B116 is increased. In this case, when the solid-state image sensor A106 is read out in the same time as the solid-state image sensor B116, it can be seen that the flicker cycle cannot be included in the image A a plurality of times. Therefore, the reading time of the solid-state image sensor A106 is lengthened, and the flicker cycle is included in the image A a plurality of times.

  As a unique effect of the present embodiment, the flicker cycle and phase can be detected even when the LV frame rate is high.

  The preferred embodiments of the present invention have been described above. Although this embodiment has been described as embodiments in LV photography, the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist.

100 cameras, 101 overall control unit / calculation unit, 102 half mirror,
104 shutter, 105 shutter driving device, 106 image sensor A,
107 imaging signal processing unit A, 108 timing generation unit A, 109 memory unit,
110 recording medium control I / F unit, 111 recording medium, 112 display drive / external I / F unit,
113 Display device, 114 External I / F, 115 Macro computer,
116 Image sensor B, 117 Image signal processor B, 118 Timing generator B,
120 ranging drive unit, 121 phase difference ranging unit (AF sensor),
200 interchangeable lens, 201 lens control unit, 202 imaging lens unit,
203 lens driving device, 204 aperture mechanism, 205 aperture driving device

Claims (8)

A solid-state imaging device A (106) and a solid-state imaging device B (116) each having a light-receiving portion that generates and accumulates photocharges according to the amount of received light, and in which the plurality of light-receiving portions are two-dimensionally arranged;
Means (101) for calculating a first accumulation time;
Means (108) for generating a first accumulation start timing signal and a read start timing signal using the first accumulation time, and controlling the accumulation and reading of photocharges of the solid-state imaging device A (106);
Means (101) for calculating a second accumulation time longer than the first accumulation time;
Means for generating a second accumulation start timing signal and a read start timing signal that include the first accumulation time in the second accumulation time, and controlling accumulation and reading of the photocharges of the solid-state imaging device B (116). 118)
Detection means (101) for detecting a timing with a small change in the amount of flicker light based on the image A obtained from the solid-state image sensor A (106);
A photographing means (101) for photographing a still image at a timing with little change in the amount of light caused by the detected flicker;
An imaging apparatus comprising: A solid-state imaging device A (106) and a solid-state imaging device B (116) each having a light-receiving portion that generates and accumulates photocharges according to the amount of received light, and in which the plurality of light-receiving portions are two-dimensionally arranged;
Means (101) for calculating a first accumulation time;
Means (101) for calculating a first readout time;
Means (101) for calculating the first readout time longer than a predetermined value;
Means for generating a first accumulation start timing signal and a read start timing signal using the first accumulation time and the first readout time, and controlling the accumulation and readout of the photoelectric charges of the solid-state imaging device A (106). (108) and
Means (101) for calculating a second accumulation time longer than the first accumulation time;
Means (101) for calculating a second readout time;
Means (2) for generating a second accumulation start timing signal and a read start timing signal using the second accumulation time and the second read time to control the accumulation and reading of the photocharges of the solid-state imaging device B (116). 118)
Detection means (101) for detecting a timing with a small change in the amount of flicker light based on the image A obtained from the solid-state image sensor A (106);
A photographing means (101) for photographing a still image at a timing with little change in the amount of light caused by the detected flicker;
An imaging apparatus comprising: The photographing apparatus according to claim 2, wherein the predetermined value is a time corresponding to a flicker period. Means (101) for obtaining an image B obtained from the solid-state image sensor B (116);
Means (101) for displaying an image B obtained from the solid-state image sensor B (116);
The image B obtained from the said solid-state image sensor B (116) is used for the display on a display part (112), The Claim 1 thru | or 3 characterized by the above-mentioned. Shooting device. The imaging apparatus according to claim 4, wherein the image A obtained from the solid-state image sensor A (106) and the image B obtained from the solid-state image sensor B (116) are periodically acquired. 6. The photographing apparatus according to claim 5, wherein the image A obtained from the solid-state imaging device A (106) is acquired intermittently. The difference in exposure amount due to the difference in accumulation time between the image A obtained from the solid-state image sensor A (106) and the image B obtained from the solid-state image sensor B (116) is determined by gain at the time of image acquisition or image processing. The imaging apparatus according to claim 4, wherein correction is performed using a gain. The presence or absence of flicker of the light source is detected from the division result of the image A obtained from the solid-state image sensor A (106) and the image B obtained from the solid-state image sensor B (116). The photographing apparatus according to any one of claims 4 to 6, wherein whether or not to perform photographing is switched based on the result, at a timing when the change in the amount of flicker light is small.