Solid-state imaging device

Abstract

[Problem] To suppress the impact of parasitic light sensitivity (PLS). [Solution] This solid-state imaging device comprises a pixel array and a control circuit. The pixel array has a plurality of light receiving pixels arranged therein. The control circuit: drives light receiving pixels for areas in the pixel array to acquire luminance values for the areas; determines a reading order on the basis of the acquired luminance values; and performs imaging by driving the plurality of light receiving pixels in the pixel array according to the reading order.

Description

solid-state imaging device

[0001] The present disclosure relates to a solid-state imaging device.

[0002] When acquiring image or video information using a solid-state imaging device, the effect of parasitic light sensitivity (PLS) in the image sensor can become a problem when there is an object that is significantly brighter than other areas. To reduce the effect of PLS, there is a method that uses live view driving to detect the position and direction of movement of a high-brightness object, and controls the readout method of the image sensor to balance and read out the light around the high-brightness object.

[0003] However, with this method, the readout patterns that can be controlled from outside the image sensor are limited, and the objects (size, position, movement direction) that can effectively suppress PLS are also limited.In addition, because readout control according to the live view results must be performed outside the image sensor, there is a problem in that the suppression effect is reduced if the object position changes while detecting the position of a high-brightness object or performing the control required for actual imaging.

[0004] Japanese Patent Publication No. 2022-127306

[0005] Therefore, one of the non-limiting problems that the embodiments of the present disclosure aim to solve is to appropriately control PLS. The problem that the embodiments of the present disclosure aim to solve can also be, as some further non-limiting examples, a problem corresponding to the effects described in the embodiments. In other words, a problem that corresponds to at least one of the effects described in the description of the embodiments of the present disclosure can be the problem that the present disclosure aims to solve.

[0006] According to one embodiment, a solid-state imaging device includes a pixel array and a control circuit. The pixel array includes a plurality of light-receiving pixels. The control circuit drives the light-receiving pixels for each region of the pixel array to obtain a luminance value for each region, determines a readout order based on the obtained luminance values, and drives the light-receiving pixels in the pixel array in accordance with the readout order to capture an image.

[0007] The plurality of light-receiving pixels may be arranged in a two-dimensional array along lines and columns in the pixel array.

[0008] The control circuit may extract areas where the brightness value across each of the acquired areas is higher than a predetermined value, and determine the read order so that the light-receiving pixels belonging to the line in which the light-receiving pixels in the area where the brightness value is higher than the predetermined value are present are read first.

[0009] The control circuit may order the acquired regions in descending order of brightness value across each region, and determine the readout order so as to read out the light-receiving pixels belonging to the line in which the light-receiving pixels of the region are located in accordance with the order.

[0010] The control circuit may extract areas where the brightness values ​​across each of the acquired areas are higher than a predetermined value, acquire a movement vector for the areas where the brightness values ​​are higher than the predetermined value, and move the areas where the brightness values ​​are higher than the predetermined value according to the movement vector, thereby determining the readout order.

[0011] The control circuit may extract areas in which the brightness value across each of the acquired areas is higher than a predetermined value, and determine the readout order so as to read out the light-receiving pixels belonging to the line in which the light-receiving pixels in the area in which the brightness value is higher than the predetermined value are located, and may not read out the light-receiving pixels belonging to the line other than the area in question.

[0012] The luminance value across each of the regions may be the sum of the luminance values ​​of the light-receiving pixels belonging to each of the regions.

[0013] The light-receiving pixels may be driven by a global shutter system.

[0014] According to one embodiment, a solid-state imaging device includes a pixel array and a control circuit. The pixel array includes a plurality of light-receiving pixels. The control circuit drives the light-receiving pixels for each region of the pixel array to obtain a luminance value for each region, and performs imaging for a line including light-receiving pixels that belong to a region where the obtained luminance value is higher than a predetermined value.

[0015] 1 is a block diagram schematically showing an example of a solid-state imaging device according to an embodiment; FIG. 1 is a diagram schematically showing an example of functional blocks of a solid-state imaging device according to an embodiment; A flowchart showing processing of a solid-state imaging device according to an embodiment; A diagram showing an example of a high-brightness object in a pixel array according to an embodiment; A diagram showing an example of a readout order according to an embodiment; A diagram showing an example of a readout order according to an embodiment; A diagram showing an example of a high-brightness object in a pixel array according to an embodiment; A flowchart showing processing of a solid-state imaging device according to an embodiment; A diagram showing an example of a high-brightness object in a pixel array according to an embodiment; A diagram showing an example of a high-brightness object in a pixel array according to an embodiment; A diagram showing an example of a high-brightness object in a pixel array according to an embodiment; A flowchart showing processing of a solid-state imaging device according to an embodiment; A diagram showing an example of a high-brightness object in a pixel array according to an embodiment; A diagram showing an example of a readout position according to an embodiment; A diagram showing an example of a readout position according to an embodiment; A diagram showing an example of a readout position according to an embodiment;

[0016] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The drawings are used for explanation purposes, and the shape, size, and size ratio of each component in an actual device do not necessarily have to be the same as those shown in the drawings. Furthermore, since the drawings are simplified, components necessary for implementation other than those shown in the drawings are also assumed to be appropriately provided.

[0017] Furthermore, in this disclosure, expressions such as "less than or equal to" and "greater than (higher)" may be used, but please note that these can be appropriately interpreted as "less than" and "greater than or equal to." For example, the expression "higher than a threshold value" in the specification and claims generally does not include a threshold value, but can be interpreted as a concept that includes a threshold value.

[0018] 1 is a block diagram schematically illustrating an example of a solid-state imaging device according to an embodiment. The solid-state imaging device 1 includes, for example, a pixel array 10, a control circuit 12, a first scanning circuit 14, a second scanning circuit 16, and a readout circuit 18. The solid-state imaging device 1 generates an image signal or a video signal (hereinafter referred to as an image signal, etc.) according to the intensity of received light. Although not shown, in addition to these components, the solid-state imaging device 1 may also include components for driving the solid-state imaging device 1, such as a power supply for supplying power to each component and an interface for inputting and outputting data to and from the outside, and / or components for user convenience.

[0019] The pixel array 10 is a region in the solid-state imaging device 1 that receives light. In the pixel array 10, for example, a plurality of pixels are arranged in a two-dimensional array along a first direction (line direction) and a second direction (column direction). Each pixel includes a light-receiving element and a circuit that appropriately transfers a signal output from the light-receiving element. In addition, the pixel may include a memory that temporarily stores an analog signal corresponding to the intensity of light received by the pixel. These configurations can be implemented, for example, by including appropriate transistors.

[0020] The control circuit 12 is a circuit that controls the output of signals from pixels belonging to the pixel array 10. In addition, in the present disclosure, the control circuit 12 can operate as a circuit that controls the readout order of pixels in the pixel array 10 in accordance with signals obtained from the readout circuit 18. The control circuit 12 controls, for example, the first scanning circuit 14 and the second scanning circuit 16 to drive appropriate pixels and control the output of signals from the pixels.

[0021] The first scanning circuit 14 is a circuit that selects a line in the pixel array 10 that outputs a signal corresponding to the intensity of received light and sets the output circuits of the pixels on the selected line to a drivable state. The first scanning circuit 14 sets each of the pixels belonging to the same line to a drivable state via signal lines 140 arranged along a first direction in the pixel array 10.

[0022] The second scanning circuit 16 is a circuit that drives pixels in the pixel array 10 that are set to a drivable state by the first scanning circuit 14. The second scanning circuit 16 is a circuit that drives pixels that are set to a drivable state by the first scanning circuit 14, and transmits signals acquired by the pixels to the readout circuit 18 via signal lines 180. The second scanning circuit 16 drives each of the pixels that belong to the same line via signal lines 160 that are arranged along the second direction in the pixel array 10.

[0023] When a pixel has a memory, the pixel may, as necessary, output the signal stored in the floating diffusion region by being driven by the first scanning circuit 14 and the second scanning circuit 16, and then transfer the signal stored in its own memory to the floating diffusion region. By performing this process, the solid-state imaging device 1 can be driven by a global shutter method in which the shutter timing is the same across the pixel array 10.

[0024] The pixels belonging to the pixel array 10 are driven by drive signals from the first scanning circuit 14 and the second scanning circuit 16, and output analog signals based on the intensity of the light received via signal lines 180 to the readout circuit 18. The readout circuit 18 can generate image data by appropriately processing the signals acquired from each pixel. The readout circuit 18 can also process the signals acquired from the pixels and output signals required for control to the control circuit 12.

[0025] The control circuit 12 may control the order of lines to be read out by the first scanning circuit 14 based on the signal obtained from the readout circuit 18. This control of the order of lines to be read out will be described in detail below.

[0026] FIG. 2 is a block diagram showing an example of a configuration showing processing units in a solid-state imaging device 1 according to an embodiment. The imaging element unit 20 controls the readout of signals from pixels. The imaging element unit 20 includes an imaging unit 200, a block readout unit 202, a threshold determination unit 204, and a readout drive unit 206. The imaging element unit 20 is configured by extracting some of the functions of the solid-state imaging device 1 as a block configuration. This configuration of the imaging element unit 20 is shown as an example, and each block does not necessarily correspond to one of the configurations of the solid-state imaging device 1 in FIG. 1.

[0027] For example, the imaging unit 200 may be part of a pixel in the pixel array 10, and the block readout unit 202, threshold determination unit 204, and readout drive unit 206 may be implemented by parts of the control circuit 12, first scanning circuit 14, second scanning circuit 16, and readout circuit 18. Also, the functions of each block may be operated by circuits other than those shown in FIG.

[0028] The imaging unit 200 acquires image data using pixels in the pixel array 10. In this case, an area is set for each of a plurality of pixels in the pixel array 10, and the pixels are driven for each of these areas. The block readout unit 202 can be configured to acquire luminance values ​​across each of these areas.

[0029] Driving the pixels for each region can be achieved, for example, by the control circuit 12 sending appropriate signals to the first scanning circuit 14 and the second scanning circuit 16. The first scanning circuit 14 and the second scanning circuit 16 cause the pixels belonging to each region to output signals based on their luminance values ​​to the readout circuit 18, thereby obtaining the luminance value for each region. The readout circuit 18 can obtain a signal related to the luminance value for each region, for example, by adding signals output from multiple pixels or bundling and obtaining outputs from multiple pixels. As an example, the luminance value for each region is expressed as the sum of the pixel values ​​(signal values ​​corresponding to the intensity values ​​of received light) belonging to that region.

[0030] The readout circuit 18 may acquire the signal related to the luminance value as an analog signal and perform subsequent processing, or may convert the analog signal related to the luminance value into a digital signal and then perform subsequent processing. The readout circuit 18 may have different circuit configurations depending on whether it is performed using an analog signal or a digital signal. For example, in the latter case, the readout circuit 18 may include an ADC and perform subsequent processing based on the signal output via the ADC.

[0031] The threshold value determination unit 204 determines the acquired luminance value for each region as a threshold value. The readout drive unit 206 determines the order in which pixels are read out in the imaging unit 200 based on the comparison result of the threshold value determination unit 204. Based on this determined order, signals from the pixels in the imaging unit 200 are read out, and actual imaging is performed. This imaging is a process in which signals are output for each pixel, not for each region.

[0032] The line number assigning unit 208 assigns a line number to each pixel value to determine which line the output signal belongs to, based on the readout order determined by the readout driving unit 206. Furthermore, instead of assigning a line number to the pixel value, data indicating the readout order, for example, data indicating the order in which the lines were read out, may be output together with the output data.

[0033] The image data assigned by the line number assignment unit 208 is appropriately processed, for example, by a logic circuit located downstream of the image sensor unit 20, rearranged and reconstructed based on the readout order, and output as image data.

[0034] The above-described sequencing and acquisition of image data will now be explained with reference to several example embodiments.

[0035] (First embodiment)

[0036] 3 is a flowchart showing an example of imaging processing according to an embodiment. The solid-state imaging device 1 according to this embodiment captures images of each region (block) in the pixel array 10 before the actual imaging, and determines regions where objects, particularly high-brightness objects, are present based on the block imaging results. The solid-state imaging device 1 determines the readout order based on the regions where objects are present, and then performs the actual imaging.

[0037] The actual photographing means receiving light at pixels belonging to the light receiving region in the pixel array 10, obtaining a luminance value for each pixel, and generating image data.

[0038] First, the solid-state imaging device 1 sets various parameters (S100). These parameters may be determined for each image capture, or may be determined in advance by a user or the like (including at the time of shipment from the factory) before image capture. When the parameters are determined for each image capture, they may be determined automatically based on, for example, the amount of light falling on the entire image sensor, the weather, the usage environment of the solid-state imaging device 1, the purpose of the solid-state imaging device 1, etc., or the user or the like may set the environment, etc.

[0039] The parameters may include, for example, a block size, a threshold value for determining high brightness, etc. However, the parameters are not limited to these, and may also include parameters related to normal photography, such as shutter speed and ISO sensitivity.

[0040] The solid-state imaging device 1 performs block imaging in accordance with the set parameters and reads out the luminance value for each block (S102). For example, the control circuit 12 controls the block imaging based on the parameters set in S100, and the readout circuit 18 acquires the luminance value for each block. Block imaging, including acquisition of the luminance value for each block, can be implemented using any existing method, and it is preferable to use a method that can be performed in a shorter time than the main imaging.

[0041] The solid-state imaging device 1 uses the block imaging results to determine the area (S104). Typically, the solid-state imaging device 1 acquires information about blocks with high brightness values. The solid-state imaging device 1 can acquire information about areas with brightness values ​​higher than the threshold value by comparing the brightness value of each block after block imaging with a threshold value.

[0042] The solid-state imaging device 1 determines the read order of the luminance values ​​so that the line including the block determined to have a high luminance value in S104 is read first (S106).

[0043] In one example, the control circuit 12 or the readout circuit 18 compares the brightness values ​​captured for each block with the threshold value set in S100 to extract areas with high brightness values. The control circuit 12 or the readout circuit 18 determines the readout order for each line so that the brightness values ​​of the line including the extracted area with high brightness values ​​are read out first.

[0044] In another example, the control circuit 12 or the readout circuit 18 orders the blocks in descending order of brightness value based on the brightness values ​​captured for each block. The control circuit 12 or the readout circuit 18 determines the readout order for each line based on this block order. For example, the control circuit 12 and / or the readout circuit 18 orders the blocks in descending order of brightness value for each block and determines the readout order for the lines included in each block so that the blocks are read out in the ordered order. The readout order of the lines within a block is arbitrary, and can be, for example, ordered along the first direction, or so that lines closer to the center of the block are read out earlier, etc.

[0045] In the above case, the luminance value of each block may be compared with a threshold value, and blocks whose luminance value is lower than the threshold value may not be ordered, but may be read out along the first direction as usual.

[0046] After determining the readout order, the solid-state imaging device 1 performs the actual photographing (S108). The actual photographing is performed, for example, by exposing the pixel array 10 and outputting signals from the pixel array 10 to the readout circuit 18 (reading out the signals). The solid-state imaging device 1 performs exposure using, for example, a global shutter system, and accumulates signals acquired by each light-receiving element in the pixel circuit. Then, reading is performed line by line in the order determined in S106.

[0047] The solid-state imaging device 1 assigns an appropriate line number to the data for which actual imaging has been completed and outputs it (S110). As described above, the solid-state imaging device 1 may output data to which a line number has been assigned as part of the format for transferring image data, or may output data indicating the readout order in parallel with the image data. Note that the concept of "output" includes output to the outside via an interface and storage in a memory unit or the like provided inside the solid-state imaging device 1.

[0048] FIG. 4 is a diagram showing an example of the location of a high-brightness subject in a pixel array 10 according to an embodiment. Note that the size of the pixel array 10 and the size of the blocks are shown as examples, and the embodiments of the present disclosure are not limited to these numerical values. The shaded circles indicate subjects. As an example, subjects O1 and O2 are high-brightness objects.

[0049] The solid-state imaging device 1 divides the pixel array 10 into regions, each block consisting of, for example, 100 x 100 pixels, and performs block imaging in S102. In the process of S104, the solid-state imaging device 1 compares the brightness value of each block with a threshold value. As a result, the solid-state imaging device 1 determines that object O1 is present in the block indicated by column numbers 501 to 600 and line numbers 201 to 300, and that object O2 is present in the block indicated by column numbers 201 to 300 and line numbers 401 to 500.

[0050] In the process of S106, the solid-state imaging device 1 determines a readout order that enables lines 201 to 300, which are lines of a block determined to have high brightness due to the presence of object O1, and lines 401 to 500, which are lines of a block determined to have high brightness due to the presence of object O2, to be read out before other lines. For example, the solid-state imaging device 1 determines the readout order so that the readout order is lines 201 to 300, lines 401 to 500, and then the other lines (for example, in the order of 1 to 200, 301 to 400).

[0051] 5 is a diagram showing an example of the readout order of lines in the actual image capture. The solid-state imaging device 1 acquires output signals from each pixel for each line based on the readout order determined in S106. This control can be processed by the control circuit 12 via the first scanning circuit 14.

[0052] The control circuit 12 outputs a signal to the first scanning circuit 14 to instruct it to first read out the 201st to 300th lines, and then the 401st to 500th lines. The first scanning circuit 14 drives the pixels belonging to each line via signal lines 140 to read out these lines in order, and based on the drive signal from the second scanning circuit 16, each pixel outputs a signal to the readout circuit 18 according to the intensity of received light.

[0053] After the readout is completed up to the 500th line, the control circuit 12 controls to read out the other lines. The readout order thereafter is arbitrary, but as described above, the readout may be performed in order from the first line, for example.

[0054] In this way, the solid-state imaging device 1 uses a block that can be used for high-speed imaging, and when the brightness value of the block is higher than a threshold value (e.g., a predetermined value, a threshold value determined by the solid-state imaging device 1 before imaging, or a user-set value), it determines a readout order so that the block is read out first, and can perform imaging based on that order.

[0055] When comparing the luminance values ​​of the blocks with the threshold value, if there is no block having a luminance value exceeding the threshold value, normal main imaging, i.e., main imaging without setting a readout order, can be performed.

[0056] 6 is a diagram showing another example of the readout order. As described in the explanation of the process of S106, the solid-state imaging device 1 can determine the readout order in descending order of block luminance value. For example, if the luminance value of object O2 is higher than the luminance value of object O1, the order can be determined so that the line in which object O2 is present is read out before the line in which object O1 is present.

[0057] In this case, the read order can be determined as shown in FIG. 6 so that the 401st to 500th lines are read out first, followed by the 201st to 300th lines.

[0058] In this way, the solid-state imaging device 1 can determine the order of lines to be read out according to the order of the luminance values ​​of the blocks. When performing this process, the solid-state imaging device 1 may determine the order of lines to be read out by sorting the luminance values ​​of all blocks in descending order, or may be configured to reflect in the read out order which block should be read out preferentially among blocks with luminance values ​​higher than a threshold value.

[0059] When sorting the luminance values ​​of all blocks in descending order, the solid-state imaging device 1 may be configured to complete sorting of the luminance values ​​of the blocks when the readout order of all lines has been determined.

[0060] 7 is a diagram showing an example of a high-brightness object in a pixel array 10 according to an embodiment. A high-brightness object does not necessarily fit into one block as in FIG. 5. As shown in this figure, a high-brightness object O3 may exist across multiple blocks.

[0061] Even in such a case, the solid-state imaging device 1 can determine the readout order in the same manner as described above. For example, the solid-state imaging device 1 can determine that the blocks of columns 201-300 and lines 201-300 are high-brightness blocks, and process the other blocks including the object O3 in the same way as normal blocks. Of course, this determination varies depending on the threshold value.

[0062] If the threshold is lower, for example, the block of columns 301-400 and lines 201-300, and the block of columns 201-300 and lines 301-400 may be determined to be high-luminance blocks. In this case, the readout order of the lines can be determined from these blocks. Of course, depending on the threshold, the block of columns 301-400 and lines 301-400 may be processed in the same way.

[0063] After capturing the image based on the readout order, the solid-state imaging device 1 can embed information about this line in a packet of image data, which is an output signal from the pixels, and output the packet. The format of the packet used for communication is not limited, but for example, the line number can be embedded in a blank bit string attached to a packet of pixel values ​​for one line.

[0064] As another example, data indicating the read order of the lines can be transmitted as data separate from the image data.

[0065] An information processing circuit inside the imaging element unit 20 or an information processing circuit outside the imaging element unit 20 can obtain appropriate image information for the actual photograph by reconstructing image information rearranged in the correct line order from data indicating the line read order (either embedded or other files are supported) and the acquired image data.

[0066] If the readout order has not been changed due to the absence of blocks with high brightness values, the information processing circuit inside or outside the image sensor unit 20 can acquire image data using a normal method that does not rearrange lines. This notification may be made, for example, by embedding the fact that the readout order has not been changed in the first packet, or may be automatically executed when the information processing circuit determines that the readout order has not been embedded.

[0067] As described above, according to this embodiment, the solid-state imaging device 1 can prioritize reading out lines included in blocks with high brightness values. By prioritizing reading out blocks with high brightness values, it is possible to suppress PLS caused by charges accumulated in pixels with high brightness values. Block imaging can be performed faster than main imaging, so it is possible to acquire data in which the effects of PLS ​​are appropriately suppressed, for example, even when acquiring video information.

[0068] (Second embodiment)

[0069] Although the above description has been given of the case where the subject is fixed, there are also cases where the subject itself is moving, or where the solid-state imaging device 1 is moving (the subject is moving relatively within the pixel array 10). The following describes processing when the position of the subject moves within the pixel array 10. Note that the processing after determining the block where the high-brightness subject is present can be the same as in the above-described embodiment.

[0070] 8 is a flowchart showing the processing of the solid-state imaging device 1 according to one embodiment. The processing steps having the same reference numerals as those in FIG. 3 basically indicate the same processing steps as those explained in relation to FIG.

[0071] The solid-state imaging device 1 repeatedly performs block imaging multiple times. Specifically, after the processes of S102 and S104, the solid-state imaging device 1 determines whether the block imaging has been repeated a predetermined number of times (S200). The predetermined number of times may be, for example, 2, or 3 or more.

[0072] The predetermined number of times may be changeable depending on the method for determining a moving object, the shooting environment, or user settings. However, since setting a too large predetermined number of times may cause delays in shooting itself, it is more preferable to set it appropriately depending on the environment, etc.

[0073] While the image capturing of the block is not completed (S200: NO), the processes of image capturing of the block, reading of the luminance value of the block, and area discrimination process (S102 and S104) are repeated.

[0074] After the image capturing of the block is completed (S200: YES), the solid-state imaging device 1 calculates the movement vector of the high-brightness subject from the multiple images of the area in the block (S202). Note that in this flowchart, the process of S104 is performed before the determination of S200, but this is not limited to this, and the process of S104 may be performed after the process of S200 or in parallel with the process of S200. Furthermore, the process of S104 may be performed in parallel with the current process of S102 based on the results of the previous block capture.

[0075] The solid-state imaging device 1 calculates a movement vector indicating the direction in which the high-luminance subject moves from data (including images) indicating the luminance values ​​of the blocks acquired in a plurality of images (S202).

[0076] The solid-state imaging device 1 obtains information about the block indicating the position of the high-brightness subject at the time of actual shooting from the current block containing the high-brightness subject and the estimated movement vector, and determines the readout order according to the information about the block after the high-brightness subject has moved (S204).

[0077] 9 is a diagram showing an example of a high-brightness object in a pixel array 10 according to an embodiment. As shown in this figure, suppose that object O4 is located in the block of columns 401-500 and lines 201-300. The solid-state imaging device 1 estimates a motion vector indicating the direction of movement of object O4 from the luminance values ​​of the block obtained in multiple images.

[0078] Fig. 10 is a diagram showing an example in which a high-brightness subject moves from the state shown in Fig. 9 at the timing of capturing the next block. When the subject moves as shown in Fig. 10, the solid-state imaging device 1 calculates the movement vector indicated by the arrow in the diagram. For example, when the subject O4 moves to a block one block above in the second direction, the solid-state imaging device 1 can estimate the movement vector as one block above.

[0079] Based on this movement vector, the solid-state imaging device 1 estimates the position of the block in which the object O4 is located at the timing of the actual photographing.

[0080] Next, the solid-state imaging device 1 determines the readout order by assuming that the position of this estimated block is the block where the high-brightness object exists at the timing of the actual shooting. For example, the solid-state imaging device 1 estimates the position of object O4 at the timing of the actual shooting by multiplying the movement vector by the ratio between the time interval between the frames of the block shooting and the time interval from the block shooting to the actual shooting.

[0081] 9 and 10, the motion vector is calculated from two images (or block positions), but this is not limited to this. The motion vector may be calculated from three or more images (or block positions). The solid-state imaging device 1 can also estimate the motion vector from three or more images using various methods.

[0082] In calculating this movement position, the solid-state imaging device 1 may ignore the first direction component (line direction component) of the movement vector, and can estimate the line position to which block the subject O4 will move from only the second direction component (column direction component).

[0083] Fig. 11 is a diagram showing an example in which a high-brightness subject moves from the state shown in Fig. 9 at the timing of the next block capture. When the subject moves as shown in Fig. 11, the solid-state imaging device 1 calculates the movement vector indicated by the arrow in the diagram. In this case, as described in the previous paragraphs, it is possible to continue the processing of S204 based on the component in the second direction only.

[0084] As described above, according to this embodiment, the solid-state imaging device 1 can reduce noise due to parasitic sensitivity even for a high-brightness object that moves in the pixel array 10, similar to the above-described embodiments.

[0085] (Third embodiment)

[0086] In the above-described embodiments, the actual photographing is performed on the entire pixel array 10, but as an application, it is also possible to perform the actual photographing on only a part of the pixel array 10.

[0087] Fig. 12 is a flowchart showing the processing of the solid-state imaging device 1 according to one embodiment. The processing steps with the same reference numerals as those in Fig. 3 basically represent the same processing steps as those explained in Fig. 3. Note that the solid-state imaging device 1 may or may not execute the processing step S106.

[0088] The solid-state imaging device 1 determines the readout order and the readout position (S300). The readout position is information specifying the position where reading will be performed in the actual imaging. For example, the solid-state imaging device 1 can perform the actual imaging only on the area corresponding to a high-brightness area, assuming that the subject is present in this area. Of course, when performing the processing of S106, the influence of PLS ​​can be suppressed by determining the readout order in descending order of brightness value for each block, for example.

[0089] In addition to readout, the solid-state imaging device 1 can also limit exposure during actual imaging based on this readout position. Furthermore, in this embodiment, not only line scanning but also column scanning can be limited to a block designated by the readout position. This control makes it possible to reduce the amount of data output from the imaging element unit 20. Furthermore, it is also possible to reduce the effects of PLS, as in the above-described embodiments.

[0090] The solid-state imaging device 1 can output the line number of the area indicating the readout position in the same manner as in the above-described embodiment. In addition, when outputting, the solid-state imaging device 1 may output data relating to only the line for which actual imaging was performed as a packet.

[0091] For this output, an information processing circuit may generate image information only in the area indicating the read position, either inside or outside the image sensor unit 20. By processing in this manner, the amount of data transfer and data processing can be reduced.

[0092] 13 is a diagram showing an example of a high-brightness object in the pixel array 10 according to an embodiment. Object O5 exists across four blocks, for example, as shown in the diagram.

[0093] 14 is a diagram showing an example of actual imaging of an object O5. The dashed line indicates the entire area of ​​the pixel array 10. In contrast, the solid-state imaging device 1 can read out only the lines corresponding to the area indicated by the solid line.

[0094] FIG. 15 is a diagram showing an example of the actual capture of object O5. The dotted line indicates the area of ​​the line that was actually captured in FIG. 14, but the solid-state imaging device 1 can also capture lines that occupy a wider area. Depending on the position of the object, the entire object may not fit within a high-brightness block. By capturing an actual image of a wider area as shown in FIG. 15, the solid-state imaging device 1 can capture the entire object as image data with a higher probability.

[0095] The number of lines to be expanded may be determined, for example, by the size of the block. For example, the solid-state imaging device 1 can perform the actual imaging by adding lines that are half or one-quarter the size of the block size in the second direction in each of the positive and negative directions of the second direction of the area indicating the readout position. These are given as non-limiting examples, and do not exclude other methods, such as using a predetermined value.

[0096] 16 is a diagram showing an example of actual photography of subject O5. In this embodiment, not only is the line limited in this way, but the column to be photographed may also be limited.

[0097] Fig. 17 is a diagram showing an example of the main photography of the subject O5. As shown in this figure, as in Fig. 15, it is also possible to perform the main photography by providing a margin in the area shown by the dotted line in Fig. 16.

[0098] As described above, according to this embodiment, it is possible to set an area indicating the readout position by performing block imaging. As a result, the amount of image data can be reduced. Furthermore, as with the previous embodiment, since readout is performed more quickly, it is also possible to suppress the effects of PLS.

[0099] Such an application can be used, for example, in a factory production line, to determine the location of an object using a fixed camera. The object may be fixed, but may also move. When the object moves, the movement vector of the second embodiment can be used.

[0100] For example, the imaging according to this embodiment may be implemented in a fixed camera that captures an image of a belt conveyor. In this case, it is possible to set a movement vector in advance, taking into account that the speed of the belt conveyor is constant.

[0101] The above-described embodiment may be modified as follows.

[0102] (1) A solid-state imaging device comprising: a pixel array; and a control circuit, wherein the pixel array has a plurality of light-receiving pixels arranged therein; the control circuit drives the light-receiving pixels for each region belonging to the pixel array to obtain a luminance value for each region; determines a readout order based on the obtained luminance values; and drives the light-receiving pixels in the pixel array in accordance with the readout order to capture an image.

[0103] (2) The solid-state imaging device according to (1), wherein the plurality of light-receiving pixels are arranged in a two-dimensional array along lines and columns in the pixel array.

[0104] (3) The solid-state imaging device described in (2), wherein the control circuit extracts areas in which the brightness value across each of the acquired areas is higher than a predetermined value, and determines the readout order so as to read out first the light-receiving pixels belonging to the line in which the light-receiving pixels in the area in which the brightness value is higher than the predetermined value exist.

[0105] (4) The solid-state imaging device described in (2) or (3), wherein the control circuit orders the regions in descending order of the brightness values ​​acquired for each region, and determines the readout order so as to read out the light-receiving pixels belonging to the line in which the light-receiving pixels of the region are located according to the order.

[0106] (5) The solid-state imaging device described in (2), wherein the control circuit extracts areas where the brightness values ​​across each of the acquired areas are higher than a predetermined value, acquires a movement vector for the areas where the brightness values ​​are higher than the predetermined value, and moves the areas where the brightness values ​​are higher than the predetermined value according to the movement vector to determine the readout order.

[0107] (6) The solid-state imaging device described in (2), wherein the control circuit extracts an area in which the brightness value across each of the acquired areas is higher than a predetermined value, determines the readout order so as to read out the light-receiving pixels belonging to the line in which the light-receiving pixels in the area in which the brightness value is higher than the predetermined value are located, and does not read out the light-receiving pixels belonging to the line other than the area in question.

[0108] (7) The solid-state imaging device according to any one of (1) to (6), wherein the luminance value across each of the regions is a sum of the luminance values ​​of the light-receiving pixels belonging to each of the regions.

[0109] (8) The solid-state imaging device according to any one of (1) to (7), wherein the light-receiving pixels are driven by a global shutter system.

[0110] (9) A solid-state imaging device comprising: a pixel array; and a control circuit, wherein the pixel array has a plurality of light-receiving pixels arranged therein; and the control circuit drives the light-receiving pixels for each region belonging to the pixel array to obtain a luminance value for each region; and performs imaging for a line including light-receiving pixels that belong to a region where the obtained luminance value is higher than a predetermined value.

[0111] The aspects of the present disclosure are not limited to the above-described embodiments and include various conceivable modifications, and the effects of the present disclosure are not limited to the above-described contents. The components in each embodiment may be appropriately combined and applied. In other words, various additions, modifications, and partial deletions are possible within the scope of the conceptual idea and intent of the present disclosure, which is derived from the content defined in the claims and their equivalents.

[0112] 1: solid-state imaging device, 10: pixel array, 12: control circuit, 14: first scanning circuit, 140: signal line, 16: second scanning circuit, 160: signal line, 18: readout circuit, 180: signal line, 20: imaging element section, 200: imaging section, 202: block readout section, 204: threshold value determination section, 206: readout driving section, 208: line number assignment section O1: subject, O2: subject, O3: subject, O4: subject, O5: subject

Claims

1. A solid-state imaging device comprising a pixel array and a control circuit, wherein a plurality of light-receiving pixels are arranged in the pixel array, and wherein the control circuit drives the light-receiving pixels for each region belonging to the pixel array to obtain a luminance value for each region, determines a readout order based on the obtained luminance values, and drives the plurality of light-receiving pixels in the pixel array in accordance with the readout order to capture an image.

2. The solid-state imaging device according to claim 1, wherein the plurality of light-receiving pixels are arranged in a two-dimensional array along lines and columns in the pixel array.

3. The solid-state imaging device of claim 2, wherein the control circuit extracts areas where the brightness value across each of the acquired areas is higher than a predetermined value, and determines the readout order so as to read out first the light-sensitive pixels belonging to the line in which the light-sensitive pixels in the area where the brightness value is higher than the predetermined value are located.

4. The solid-state imaging device of claim 2, wherein the control circuit orders the acquired regions in descending order of luminance value across each region, and determines the readout order so as to read out the light-sensitive pixels belonging to the line in which the light-sensitive pixels of the region are located in accordance with the order.

5. The solid-state imaging device of claim 2, wherein the control circuit extracts areas where the brightness values ​​across each of the acquired areas are higher than a predetermined value, acquires a movement vector for the areas where the brightness values ​​are higher than the predetermined value, and moves the areas where the brightness values ​​are higher than the predetermined value according to the movement vector, thereby determining the readout order.

6. The solid-state imaging device of claim 2, wherein the control circuit extracts an area in which the brightness value across each of the acquired areas is higher than a predetermined value, determines the readout order so as to read out the light-receiving pixels belonging to the line in which the light-receiving pixels in the area in which the brightness value is higher than the predetermined value are located, and does not read out the light-receiving pixels belonging to the line other than the area in question.

7. The solid-state imaging device according to claim 1, wherein the luminance value across each of the regions is the sum of the luminance values ​​of the light-receiving pixels belonging to each of the regions.

8. The solid-state imaging device according to claim 1, wherein the light-receiving pixels are driven by a global shutter system.

9. A solid-state imaging device comprising a pixel array and a control circuit, wherein a plurality of light-receiving pixels are arranged in the pixel array, and wherein the control circuit drives the light-receiving pixels for each region belonging to the pixel array to obtain a luminance value for each region, and performs imaging for a line including light-receiving pixels that belong to a region where the obtained luminance value is higher than a predetermined value.

Images