Imaging element

Abstract

To enhance the accuracy in black level correction.SOLUTION: An imaging element comprises: an imaging region that has a plurality of first pixels each including a first photoelectric conversion part and a first circuit part and arranged in a first direction and a second direction, a first control line to which signals for controlling the plurality of first pixels are outputted, and a first output line for outputting signals generated at the plurality of first pixels; and a plurality of light-shielding pixel regions each of which has a plurality of second pixels each including a shielded second photoelectric conversion part and a second circuit part and arranged in the first direction and the second direction, a second control line to which signals for controlling the second pixels are outputted, and a second output line for outputting signals generated at the plurality of second pixels. The light-shielding pixel regions are arranged outside a region incorporating all first pixels included in the imaging region. The imaging element has: an imaging pixel region in which different control conditions can be respectively set for the plurality of imaging regions; and an optical black pixel region in which the same control condition as a reference source imaging region can be respectively set for the plurality of light-shielding pixel regions.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an imaging element and an imaging device. [Background technology]

[0002] Patent Document 1 discloses a charge-coupled device having an optical black area where a photodiode is arranged and an optical black area where no photodiode is arranged. However, the charge-coupled device of Patent Document 1 does not take into consideration a plurality of pixel areas where different control conditions are set. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-303856 Summary of the Invention

[0004] The image sensor includes an imaging region having a first photoelectric conversion unit that receives light from an optical system and converts it into an electric charge and a first circuit unit connected to the first photoelectric conversion unit, the imaging region having a plurality of first pixels arranged in a first direction and a second direction intersecting the first direction, a first control line connected to the plurality of first pixels and outputting a signal that controls the plurality of first pixels, and a first output line connected to the plurality of first pixels and outputting a signal generated by the plurality of first pixels, a light-shielded second photoelectric conversion unit and a second circuit unit connected to the second photoelectric conversion unit, the imaging region having a plurality of second pixels arranged in the first direction and the second direction, and a first control line connected to the plurality of first pixels and outputting a signal that controls the plurality of first pixels. and a plurality of light-shielding pixel regions each having a second control line through which a signal for controlling the second pixel is output, and a second output line different from the first output line connected to the plurality of second pixels and outputting a signal generated by the plurality of second pixels, wherein the light-shielding pixel region is arranged outside an area that includes all of the first pixels of the imaging region and is connected to the first control line of the imaging region, the light-shielding pixel region having a plurality of the imaging regions, and wherein different control conditions can be set for each of the plurality of imaging regions, and an optical black pixel region in which the same control conditions as those of a reference imaging region can be set for each of the plurality of light-shielding pixel regions. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 is a cross-sectional view of a stacked imaging device. [Figure 2] FIG. 2 is a diagram illustrating the pixel arrangement of the imaging chip. [Figure 3] FIG. 3 is a circuit diagram of the imaging chip. [Figure 4] FIG. 4 is a block diagram showing an example of the configuration of an imaging element. [Figure 5] FIG. 5 is an explanatory diagram illustrating an example of a block configuration of an electronic device. [Figure 6] FIG. 6 is an explanatory diagram showing a relationship 1 between the control conditions for the imaging pixel region and the control conditions for the optical black pixel region. [Figure 7] FIG. 7 is a circuit diagram showing the circuit configuration of the imaging pixel area and the optical black pixel area in the row direction. [Figure 8] FIG. 8 is a circuit diagram showing the circuit configuration of the imaging pixel area and the optical black pixel area in the column direction. [Figure 9] FIG. 9 is a timing chart showing the operation of the block. [Figure 10] FIG. 10 is an explanatory diagram showing a relationship 2 between the control conditions for the imaging pixel region and the control conditions for the optical black pixel region. [Figure 11] FIG. 11 is an explanatory diagram showing a relationship 3 between the control conditions for the imaging pixel region and the control conditions for the optical black pixel region. [Figure 12] FIG. 12 is a block diagram showing another example of an optically black pixel with a PD. [Figure 13] FIG. 13 is an explanatory diagram illustrating the relationship between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region according to the second embodiment. [Figure 14] FIG. 14 is a diagram illustrating an example of the correction table according to the second embodiment. [Figure 15] FIG. 15 is a circuit diagram showing the circuit configuration of the imaging pixel area and the optical black pixel area in the column direction. [Figure 16] FIG. 16 is an explanatory diagram illustrating a relationship 1 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region according to the third embodiment. [Figure 17] FIG. 17 is an explanatory diagram illustrating a relationship 2 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region according to the third embodiment. [Figure 18] FIG. 18 is an explanatory diagram illustrating the relationship between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region according to the fourth embodiment. [Figure 19] FIG. 19 is a diagram illustrating an example of a correction table according to the fourth embodiment. [Figure 20] FIG. 20 is a circuit diagram showing the circuit configuration of the imaging pixel area and the optical black pixel area in the row direction. [Figure 21] FIG. 21 is an explanatory diagram showing a relationship 1 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region according to the fifth embodiment. [Figure 22]FIG. 22 is an explanatory diagram illustrating a relationship 2 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region according to the fifth embodiment. [Figure 23] FIG. 23 is an explanatory diagram showing a relationship 1 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region according to the sixth embodiment. [Figure 24] FIG. 24 is an explanatory diagram showing a relationship 2 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region according to the sixth embodiment. [Figure 25] FIG. 25 is a diagram illustrating an example of a correction table according to the sixth embodiment. [Figure 26] FIG. 26 is an explanatory diagram showing the relationship between the control conditions for the imaging pixel region and the control conditions for the optical black pixel region. [Figure 27] FIG. 27 is a diagram illustrating an example of a correction table according to the seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0006] <Example of imaging element configuration> The imaging element mounted on the electronic device shown in the examples of this specification is a stacked imaging element. This stacked imaging element allows different imaging conditions (control conditions) to be set for each of a plurality of different imaging regions. First, the structure of the stacked imaging element that allows different imaging conditions (control conditions) to be set for each of a plurality of different imaging regions will be described. This stacked imaging element is described in Japanese Patent Application No. 2012-139026, previously filed by the applicant of this application. The electronic device is, for example, an imaging device such as a digital camera or a digital video camera.

[0007] 1 is a cross-sectional view of a stacked imaging element 100. The stacked imaging element (hereinafter simply referred to as "imaging element") 100 includes a back-illuminated imaging chip (hereinafter simply referred to as "imaging chip") 113 that outputs pixel signals corresponding to incident light, a signal processing chip 111 that processes the pixel signals, and a memory chip 112 that stores the pixel signals. The imaging chip 113, signal processing chip 111, and memory chip 112 are stacked and electrically connected to each other by conductive bumps 109 such as Cu.

[0008] As shown in FIG. 1, incident light is mainly incident in the positive direction of the Z axis, as indicated by the white arrow. In this embodiment, the surface of the imaging chip 113 on which the incident light is incident is referred to as the back surface. As shown in coordinate axes 120, the left direction on the paper, perpendicular to the Z axis, is the positive X axis, and the front direction on the paper, perpendicular to the Z axis and the X axis, is the positive Y axis. In the following figures, the coordinate axes 120 in FIG. 1 are used as the reference, and the coordinate axes 120 are displayed so that the orientation of each figure can be understood.

[0009] An example of the imaging chip 113 is a back-illuminated MOS (Metal Oxide Semiconductor) image sensor. A PD (Photodiode) layer 106 is arranged on the back side of a wiring layer 108. The PD layer 106 has a plurality of PDs 104 arranged two-dimensionally and accumulating electric charges according to incident light, and transistors 105 provided corresponding to the PDs 104.

[0010] A color filter 102 is provided on the incident side of the PD layer 106, on which incident light is incident, via a passivation film 103. There are multiple types of color filters 102 that transmit different wavelength ranges, and each has a specific arrangement corresponding to each PD 104. The arrangement of the color filters 102 will be described later. A set of a color filter 102, a PD 104, and a transistor 105 forms one pixel.

[0011] A microlens 101 is provided corresponding to each pixel on the incident light side of the color filter 102. The microlens 101 condenses the incident light toward the corresponding PD 104.

[0012] The wiring layer 108 has wiring 107 that transmits pixel signals from the PD layer 106 to the signal processing chip 111. The wiring 107 may be multi-layered, and may be provided with passive elements and active elements.

[0013] A plurality of bumps 109 are arranged on the surface of the wiring layer 108. The plurality of bumps 109 are aligned with a plurality of bumps 109 provided on the opposing surface of the signal processing chip 111, and the imaging chip 113 and the signal processing chip 111 are pressed together, whereby the aligned bumps 109 are bonded together and electrically connected.

[0014] Similarly, a plurality of bumps 109 are arranged on the opposing surfaces of the signal processing chip 111 and the memory chip 112. These bumps 109 are aligned with each other, and the signal processing chip 111 and the memory chip 112 are pressed together, whereby the aligned bumps 109 are bonded together and electrically connected.

[0015] The bonding between the bumps 109 is not limited to Cu bump bonding by solid-phase diffusion, but may also employ micro-bump bonding by solder melting. For example, it is sufficient to provide approximately one bump 109 per block, as will be described later. Therefore, the size of the bumps 109 may be larger than the pitch of the PDs 104. Furthermore, in a peripheral region other than the pixel region where the pixels are arranged, bumps larger than the bumps 109 corresponding to the pixel region may also be provided.

[0016] The signal processing chip 111 has through-silicon vias (TSVs) 110 that connect circuits provided on the front and back surfaces of the chip to each other. The TSVs 110 are preferably provided in the peripheral region. The TSVs 110 may also be provided in the peripheral region of the imaging chip 113 and the memory chip 112.

[0017] 2 is a diagram illustrating the pixel arrangement of the imaging chip 113. In particular, it shows the imaging chip 113 observed from the back side. (a) is a plan view schematically showing an imaging surface 200, which is the back side of the imaging chip 113, and (b) is an enlarged plan view of a partial region 200a of the imaging surface 200. As shown in (b), a large number of pixels 201 are arranged two-dimensionally on the imaging surface 200.

[0018] Each pixel 201 has a color filter (not shown). The color filters are of three types: red (R), green (G), and blue (B), and the notations "R," "G," and "B" in (b) indicate the type of color filter that the pixel 201 has. As shown in (b), the pixels 201 equipped with such color filters are arranged in a so-called Bayer array on the imaging surface 200 of the image sensor 100.

[0019] The pixel 201 having a red filter photoelectrically converts light in the red wavelength band of the incident light and outputs a light reception signal (photoelectric conversion signal). Similarly, the pixel 201 having a green filter photoelectrically converts light in the green wavelength band of the incident light and outputs a light reception signal. Furthermore, the pixel 201 having a blue filter photoelectrically converts light in the blue wavelength band of the incident light and outputs a light reception signal.

[0020] The image sensor 100 is configured so that each block 202, each consisting of four adjacent pixels 201 (2 pixels x 2 pixels), can be controlled individually. For example, when charge accumulation starts simultaneously in two different blocks 202, charge readout, i.e., light reception signal readout, can be performed 1 / 30 second after the start of charge accumulation in one block 202, and charge readout can be performed 1 / 15 second after the start of charge accumulation in the other block 202. In other words, the image sensor 100 can set a different exposure time (charge accumulation time, also known as shutter speed) for each block 202 during a single image capture.

[0021] In addition to the exposure time described above, the image sensor 100 can vary the amplification factor of the image signal (so-called ISO sensitivity) for each block 202. The image sensor 100 can change the timing for starting charge accumulation and the timing for reading out the light-receiving signal for each block 202. In other words, the image sensor 100 can change the frame rate for capturing moving images for each block 202.

[0022] In summary, the image sensor 100 is configured to be able to vary imaging conditions (control conditions) such as exposure time, amplification factor, and frame rate for each block 202. For example, if a readout line (not shown) for reading out imaging signals from a photoelectric conversion unit (not shown) included in the pixel 201 is provided for each block 202 and imaging signals can be read out independently for each block 202, it is possible to vary the exposure time (shutter speed) for each block 202.

[0023] Furthermore, if an amplifier circuit (not shown) that amplifies the image signal generated by the photoelectrically converted charge is provided independently for each block 202 and the amplification factor of the amplifier circuit is configured to be controllable independently for each amplifier circuit, the signal amplification factor (ISO sensitivity) can be made different for each block 202.

[0024] Furthermore, imaging conditions (control conditions) that can be varied for each block 202 include, in addition to the imaging conditions (control conditions) described above, the frame rate, gain, resolution (thinning rate), the number of rows or columns for adding pixel signals, the charge accumulation time or number of accumulations, the number of digitization bits, etc. Furthermore, the control parameters may be parameters for image processing after image signals are acquired from the pixels.

[0025] Furthermore, as for the imaging conditions (control conditions), for example, if an LCD panel having independently controllable sections (each section corresponds to one block 202) for each block 202 is provided in the imaging element 100 and used as an on / off neutral density filter, it becomes possible to control the brightness (aperture value) for each block 202.

[0026] The number of pixels 201 constituting the block 202 does not have to be the four pixels of 2×2 described above. The block 202 only needs to have at least two pixels 201, and conversely, the block 202 may have more than four pixels 201.

[0027] 3 is a circuit diagram of the imaging chip 113. In FIG. 3, a rectangle surrounded by a dotted line typically represents a circuit corresponding to one pixel 201. A rectangle surrounded by a dashed line corresponds to one block 202 (202-1 to 202-4). At least some of the transistors described below correspond to the transistors 105 in FIG. 1.

[0028] As described above, the reset transistors 303 of the pixels 201 are turned on / off in units of blocks 202. The transfer transistors 302 of the pixels 201 are also turned on / off in units of blocks 202. In the example shown in Fig. 3, a reset wiring 300-1 is provided for turning on / off the four reset transistors 303 corresponding to the upper left block 202-1, and a TX wiring 307-1 is also provided for supplying transfer pulses to the four transfer transistors 302 corresponding to the same block 202-1.

[0029] Similarly, a reset wiring 300-3 for turning on / off the four reset transistors 303 corresponding to the lower left block 202-3 is provided separately from the reset wiring 300-1. Also, a TX wiring 307-3 for supplying transfer pulses to the four transfer transistors 302 corresponding to the same block 202-3 is provided separately from the TX wiring 307-1.

[0030] Similarly, in the upper right block 202-2 and the lower right block 202-4, a reset line 300-2 and a TX line 307-2, and a reset line 300-4 and a TX line 307-4 are provided in each block 202, respectively.

[0031] The 16 PDs 104 corresponding to each pixel 201 are connected to the corresponding transfer transistor 302. A transfer pulse is supplied to the gate of each transfer transistor 302 via the TX wiring for each block 202. The drain of each transfer transistor 302 is connected to the source of the corresponding reset transistor 303, and a so-called floating diffusion FD between the drain of the transfer transistor 302 and the source of the reset transistor 303 is connected to the gate of the corresponding amplification transistor 304.

[0032] The drains of the reset transistors 303 are commonly connected to a Vdd wiring 310 to which a power supply voltage is supplied. A reset pulse is supplied to the gate of each reset transistor 303 via the reset wiring for each block 202.

[0033] The drains of the amplifier transistors 304 are commonly connected to a Vdd line 310 to which a power supply voltage is supplied. The source of each amplifier transistor 304 is connected to the drain of the corresponding selection transistor 305. The gate of each selection transistor 305 is connected to a decoder line 308 to which a selection pulse is supplied. The decoder line 308 is provided independently for each of the 16 selection transistors 305.

[0034] The sources of the selection transistors 305 are connected to a common output wiring 309. A load current source 311 supplies a current to the output wiring 309. That is, the output wiring 309 for the selection transistors 305 is formed by a source follower. The load current source 311 may be provided on the imaging chip 113 side or on the signal processing chip 111 side.

[0035] Here, we will explain the flow from the start of charge accumulation to pixel output after accumulation ends. A reset pulse is applied to the reset transistor 303 through the reset wiring for each block 202, and at the same time, a transfer pulse is applied to the transfer transistor 302 through the TX wiring for each block 202 (202-1 to 202-4). This resets the potentials of the PD 104 and floating diffusion FD for each block 202.

[0036] When the transfer pulse is released, each PD 104 converts the incident light it receives into electric charges and stores them. After that, when the transfer pulse is applied again without the reset pulse being applied, the stored electric charges are transferred to the floating diffusion FD, and the potential of the floating diffusion FD changes from the reset potential to the signal potential after the electric charges are stored.

[0037] When a selection pulse is applied to the selection transistor 305 through the decoder wiring 308, a fluctuation in the signal potential of the floating diffusion FD is transmitted to the output wiring 309 via the amplification transistor 304 and the selection transistor 305. As a result, a pixel signal corresponding to the reset potential and the signal potential is output from the unit pixel to the output wiring 309.

[0038] As described above, the reset wiring and TX wiring are common to the four pixels that form a block 202. That is, the reset pulse and transfer pulse are each applied simultaneously to the four pixels in the same block 202. Therefore, all of the pixels 201 that form a certain block 202 start and end charge accumulation at the same timing. However, pixel signals corresponding to the accumulated charges are selectively output from the output wiring 309 by sequentially applying selection pulses to the respective selection transistors 305.

[0039] In this way, the charge accumulation start timing can be controlled for each block 202. In other words, different blocks 202 can capture images at different timings.

[0040] 4 is a block diagram showing an example configuration of the image sensor 100. An analog multiplexer 411 sequentially selects the 16 PDs 104 that form a block 202 and outputs the pixel signals from each of the 16 PDs 104 to the output wiring 309 provided corresponding to the block 202. The multiplexer 411 is formed on the image sensor chip 113 together with the PDs 104.

[0041] The pixel signals output via the multiplexer 411 undergo correlated double sampling (CDS) and analog-to-digital (A / D) conversion by a signal processing circuit 412 that performs CDS and A / D conversion and is formed in the signal processing chip 111. The A / D converted pixel signals are passed to a demultiplexer 413 and stored in pixel memories 414 corresponding to the respective pixels. The demultiplexer 413 and pixel memories 414 are formed in the memory chip 112.

[0042] The arithmetic circuit 415 processes the pixel signals stored in the pixel memory 414 and passes them to a downstream image processing unit. The arithmetic circuit 415 may be provided in the signal processing chip 111 or in the memory chip 112. Note that although Fig. 4 shows connections for four blocks 202, in reality, these exist for every four blocks 202 and operate in parallel.

[0043] However, it is not necessary for there to be an arithmetic circuit 415 for each of the four blocks 202; for example, one arithmetic circuit 415 may perform sequential processing by referring to the values ​​of the pixel memories 414 corresponding to each of the four blocks 202 in order.

[0044] As described above, output wiring 309 is provided corresponding to each block 202. Since the image sensor 100 has the image pickup chip 113, signal processing chip 111, and memory chip 112 stacked on top of each other, by using bumps 109 for electrical connection between the chips for these output wiring 309, it is possible to route the wiring without increasing the size of each chip in the planar direction.

[0045] <Example of block configuration of electronic device> 5 is an explanatory diagram showing an example block configuration of an electronic device. Electronic device 500 is, for example, a lens-integrated camera. Electronic device 500 includes imaging optical system 501, imaging element 100, control unit 502, LCD monitor 503, memory card 504, operation unit 505, DRAM 506, flash memory 507, and sound recording unit 508. Control unit 502 includes a detection unit that detects camera shake and subject shake, as will be described later.

[0046] The imaging optical system 501 is made up of a plurality of lenses, and forms a subject image on the imaging surface 200 of the image sensor 100. For convenience, the imaging optical system 501 is illustrated as a single lens in FIG.

[0047] The imaging element 100 is, for example, an imaging element such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device), and captures an image of a subject formed by an imaging optical system 501 and outputs an imaging signal. The control unit 502 is an electronic circuit that controls each unit of the electronic device 500, and includes a processor that executes a program, peripheral circuits such as an image processing circuit, and various sensors such as an acceleration sensor.

[0048] A predetermined control program is written in advance in flash memory 507, which is a non-volatile storage medium. The processor of control unit 502 controls each unit by reading and executing the control program from flash memory 507. This control program uses DRAM 506, which is a volatile storage medium, as a working area.

[0049] The liquid crystal monitor 503 is a display device that uses a liquid crystal panel. The control unit 502 causes the image sensor 100 to repeatedly capture an image of a subject at predetermined intervals (for example, 1 / 60th of a second). Then, various types of image processing are performed on the image signal output from the image sensor 100 to create a so-called through image, which is displayed on the liquid crystal monitor 503. In addition to the through image, the liquid crystal monitor 503 displays, for example, a setting screen for setting image capturing conditions (control conditions).

[0050] The control unit 502 creates an image file (described later) based on the imaging signal output from the imaging element 100, and records the image file on a portable recording medium, such as a memory card 504. The operation unit 505 has various operation members such as push buttons, and outputs operation signals to the control unit 502 in response to the operation of these operation members.

[0051] Recording unit 508 is configured with, for example, a microphone, and converts environmental sounds into audio signals and inputs them to control unit 502. Note that control unit 502 may record the video file on a recording medium (not shown), such as an SSD (Solid State Drive) or hard disk, built into electronic device 500, instead of recording the video file on memory card 504, which is a portable recording medium.

[0052] 1 to 5 above have been used to explain the parts common to the following embodiments. Now, the imaging element and imaging device according to each embodiment will be explained. [Example]

[0053] The first embodiment has a configuration in which the number of non-imaging regions in the optical black pixel region is equal to or greater than the number of imaging regions in the imaging pixel region, and the non-imaging regions are arranged in positions different from the imaging pixel regions.

[0054] <Relationship between control conditions for the imaging pixel area and the optical black pixel area> Next, the control conditions for the imaging pixel area, the control conditions for the optical black pixel area, and the arrangement of the imaging pixel area and the optical black pixel area according to the first embodiment will be described with reference to Fig. 6, Fig. 10, and Fig. 11. In Fig. 10 and Fig. 11, the description will focus on the differences from Fig. 6, and therefore the description of the same parts as Fig. 6 will be omitted.

[0055] FIG. 6 is an explanatory diagram showing a relationship 1 between the control conditions for the imaging pixel region and the control conditions for the optical black pixel region according to the first embodiment. In FIG. 6, the x direction is the row direction, and the y direction is the column direction. The imaging surface 200 shown in FIG. 2 has an imaging pixel region 600 and an optical black pixel region 610. Here, the imaging pixel region 600 is a region in which imaging pixels 6, each having a plurality of PDs 104 that accumulate charges according to incident light, are arranged two-dimensionally. The optical black pixels have the same structure as the pixels arranged in the imaging pixel region, but the PDs 104 are light-shielded. The optical black pixel region 610 is, for example, a region in which optical black pixels are arranged one-dimensionally or two-dimensionally.

[0056] The imaging region is, for example, a collection of one or more blocks 202. In FIG. 6, for simplicity of explanation, the imaging pixel region 600 is configured by imaging regions 600-11, 600-12, 600-21, and 600-22 arranged in two rows and two columns. However, the imaging pixel region 600 may be configured by m rows and n columns (m and n are integers equal to or greater than 1, provided that there are two or more imaging regions 600) other than two rows and two columns. When there is no need to distinguish between the imaging regions 600-11, 600-12, 600-21, and 600-22, they are referred to as imaging regions 600-ij. Each imaging region 600-ij can be controlled under control conditions different from those of the other imaging regions 600-ij.

[0057] The optical black pixel region 610 is composed of multiple non-imaging regions 610-L1 to 610-L4 and 610-C1 to 610-C4 that do not capture an image of a subject. Each of the non-imaging regions 610-L1 to 610-L4 and 610-C1 to 610-C4 includes at least one of a group of optical black pixels without a PD and a group of optical black pixels with a PD, which will be described later.

[0058] The optical black pixel groups without PD or the optical black pixel groups with PD in each of the non-imaging regions 610-L1 to 610-L4 and 610-C1 to 610-C4 have a configuration in which the pixels are arranged two-dimensionally, similar to block 202 described with reference to Fig. 3. The optical black pixel groups without PD or the optical black pixel groups with PD have a configuration in which they can be controlled under different control conditions for each of the non-imaging regions 610-L1 to 610-L4 and 610-C1 to 610-C4.

[0059] Here, in each embodiment, a non-imaging region having a group of optically black pixels without PD is also referred to as a light-shielded pixel region. The multiple non-imaging regions 610-L1 to 610-L4 are a group of non-imaging regions existing in the column direction. When the group of non-imaging regions existing in the column direction is not distinguished, they are referred to as non-imaging region 610-Lp. The multiple non-imaging regions 610-C1 to 610-C4 are a group of non-imaging regions existing in the row direction.

[0060] When the group of non-imaging regions existing in the row direction is not distinguished, they are referred to as non-imaging region 610-Cq. When the multiple non-imaging regions 610-L1 to 610-L4 and 610-C1 to 610-C4 are not distinguished, they are referred to as non-imaging region 610-pq. One non-imaging region 610-pq includes a group of optical black pixels with PD and a group of optical black pixels without PD.

[0061] The optical black pixel region 610 is adjacent to the outside of the imaging pixel region 600. In Fig. 6, for example, the optical black pixel region 610 is provided at the right end and bottom end of the imaging pixel region 600. The optical black pixel region 610 may be located at at least one of the top end, bottom end, right end, and left end of the imaging pixel region 600.

[0062] The optical black pixel region 610 includes a group of optical black pixels with PD and a group of optical black pixels without PD. The group of optical black pixels with PD is a collection of optical black pixels with PD. The optical black pixels with PD are black pixels that have PD 104. Specifically, for example, the optical black pixels with PD are pixels that have a light-shielding layer that blocks the incidence of subject light.

[0063] The group of optical black pixels without PD is a collection of optical black pixels without PD. Optical black pixels without PD are black pixels that do not have a PD 104. By subtracting the output from the optical black pixels with PD or the output signal from the optical black pixels without PD from the output signal from the imaging pixel, black level correction is performed and noise such as dark current components is removed.

[0064] The number of non-imaging regions 610-pq is equal to or greater than the number of imaging regions 600-ij. In Fig. 6, the number of non-imaging regions 610-pq is eight, and the number of imaging regions 600-ij is four.

[0065] The non-imaging region 610-Cq is arranged in two rows and two columns. The non-imaging regions 610-C1 and 610-C3 are arranged in the column direction, with the PD-less optical black pixel group of the non-imaging region 610-C1 adjacent to the PD-less optical black pixel group of the non-imaging region 610-C3. Similarly, the non-imaging regions 610-C2 and 610-C4 are arranged in the column direction, with the PD-less optical black pixel group of the non-imaging region 610-C2 adjacent to the PD-less optical black pixel group of the non-imaging region 610-C4. In this way, the PD-less optical black pixel group of the non-imaging region 610-Cq is not separated, so the number of PD-less optical black pixel groups can be reduced, thereby reducing manufacturing costs.

[0066] <Circuit configuration of the imaging pixel area 600 and the optical black pixel area 610> Fig. 7 is a circuit diagram showing the circuit configuration of the imaging pixel region 600 and the optical black pixel region 610 in the row direction according to Example 1. Fig. 8 is a circuit diagram showing the circuit configuration of the imaging pixel region 600 and the optical black pixel region 610 in the column direction according to Example 1. In Fig. 7 and Fig. 8, the pixel 201 in the imaging pixel region 600 is referred to as an imaging pixel 201-1, and the pixel 201 in the optical black pixel region 610 is referred to as an optical black pixel with PD 201-2 and an optical black pixel without PD 201-3.

[0067] The pixel 201 includes a transfer transistor 302, a reset transistor 303, an amplification transistor 304, a selection transistor 305, and a floating diffusion FD. The imaging pixel 201-1 further includes a red (R), green (G), or blue (B) color filter 102 and a PD 104. The PD-equipped optically black pixel 201-2 further includes a light-shielding layer 700 and a PD 104. The PD-less optically black pixel 201-3 does not include a filter or a PD 104.

[0068] The imaging pixel 201-1 generates a charge according to the amount of light incident through the color filter 102. On the other hand, the PD-equipped optical black pixel 201-2 has a light-shielding layer 700, and therefore does not generate a charge according to the amount of incident light, but generates a charge equivalent to thermal noise.

[0069] The transfer transistors 302 of the imaging pixel 201-1 and the optically black pixel with PD 201-2 transfer the charge accumulated in the PD 104 to the floating diffusion FD when control signals TX_C and TX_O1 are applied to their gates from the drive circuit 711. The transfer transistor 302 of the optically black pixel without PD 201-3 does not generate charge due to the PD 104 even when the control signal TX_O2 from the drive circuit 711 is applied to its gate.

[0070] The reset transistor 303 sets the potential of the floating diffusion FD to approximately the same potential as Vdd when a control signal RST is given to its gate from the drive circuit 711. For example, the reset transistor 303 removes electrons accumulated in the floating diffusion FD.

[0071] When control signals SEL_C, SEL_O1, and SEL_O2 from a drive circuit 711 are applied to the gates of the selection transistors 305, the selection transistors 305 output currents to the column readout lines 701 to 703 at voltages amplified by the amplification transistors 304. The column readout lines 701-1 to 701-4 in FIG. 8 correspond to the column readout line 701 in FIG.

[0072] A pixel signal corresponding to the charge generated by the PD 104 is output from the column readout line 701. A signal corresponding to a voltage level corresponding to thermal noise is output from the column readout line 702. A signal corresponding to a reference black level is output from the column readout line 703. The column readout lines 701 to 703 are connected to a signal processing unit 710 via a CDS circuit, an AD conversion circuit, etc. (not shown).

[0073] The signal processing unit 710 receives a signal corresponding to the amount of charge photoelectrically converted in the imaging pixel 201-1. The signal processing unit 710 receives a signal corresponding to thermal noise detected in the optically black pixel with PD 201-2. The signal processing unit 710 uses the signal from the optically black pixel without PD 201-3 as the reference for the black level of the imaging pixel 201-1.

[0074] The signal processing unit 710 performs black level correction by subtracting the output signal from the optical black pixel with PD 201-2 or the output signal from the optical black pixel without PD 201-3 from the output signal from the imaging pixel 201-1. This removes noise such as dark current. The signal processing unit 710 may be realized by a circuit, or may be realized by a processor executing a program stored in memory.

[0075] A drive circuit 711 (not shown in FIG. 8) supplies control signals TX, RST, and SEL as signal pulses to the gates of the transfer transistor 302, the reset transistor 303, and the selection transistor 305. This turns on the transfer transistor 302, the reset transistor 303, and the selection transistor 305.

[0076] The control unit 712 (not shown in FIG. 8 ) controls the drive circuit 711. The control unit 712 controls the transfer transistor 302, the reset transistor 303, and the selection transistor 305 by controlling the pulse timing to each gate of the transfer transistor 302, the reset transistor 303, and the selection transistor 305. The control unit 712 also controls the operation of the signal processing unit 710.

[0077] <Timing chart showing the operation of block 202> 9 is a timing chart showing the operation of the block 202 according to the first embodiment. In one block 202, the drive circuit 711 controls the transfer transistor 302 and the reset transistor 303 at the same timing. However, for pixels 201 provided with color filters 102 having the same spectral characteristics, the drive circuit 711 outputs pixel signals from the selection transistors 305 at different timings for each pixel 201.

[0078] For example, at time t2, the drive circuit 711 turns on each reset transistor 303 (RST) of one block 202. This resets the potential of the gate of each amplification transistor 304. The drive circuit 711 keeps each reset transistor 303 (RST) in the on state from time t2 to time t5.

[0079] At time t3, the drive circuit 711 turns on all the transfer transistors 302 in one block 202. As a result, first, the charge accumulated in the PD 104 present in the block 202 is reset.

[0080] At time t5, the drive circuit 711 turns off each reset transistor 303 (RST). Then, at time t7, the drive circuit 711 turns on all transfer transistors 302 in one block 202 again. As a result, the charges accumulated in the PDs 104 present in one block 202 are transferred to the corresponding floating diffusions FD.

[0081] In the period from time t3 to time t7, the pixel 201 having the PD 104 in one block 202 accumulates charge. That is, the period from time t3 to time t7 is the charge accumulation period of the pixel 201 having the PD 104.

[0082] After time t8, the drive circuit 711 sequentially turns on the transfer transistors 302. In this example, at time t8, the charges accumulated in the PDs 104 in one block 202 are transferred to, for example, the column read lines 701 to 703, respectively.

[0083] Furthermore, at time t9, the charges accumulated in the other PDs 104 in the other blocks 202 are transferred to the column readout lines 701 to 703, respectively. This transfer operation is performed for each pixel 201 in one block 202. As a result, pixel signals of the pixels 201 included in one block 202 are output to the column readout lines 701 to 703, respectively.

[0084] Returning to Fig. 6, the positional relationship between the imaging region 600-ij and the non-imaging region 610-pq will be described. As described above, each imaging region 600-ij has a configuration in which imaging pixels 6 are arranged two-dimensionally. The imaging pixels 6 of each imaging region 600-ij have a configuration similar to that of block 202 described using Fig. 2, for example, and each imaging region 600-ij can be controlled under different control conditions.

[0085] Consider a closed region 60 that includes all of the imaging pixels 6 of each imaging region 600-ij and is connected to the control lines (TX wiring 307, etc.) of the imaging region 600-ij, and that is specified so that its outer edge has the shortest length. The non-imaging region 610-pq is located outside this closed region 60. With this configuration, it is possible to uniformly arrange the imaging pixels 6 inside each imaging region 600-ij. Therefore, so-called defective pixels are not generated, and high quality can be ensured for images generated by the imaging pixels 6 of each imaging region 600-ij.

[0086] Next, the control conditions and black level correction set for the imaging pixel region 600 and the optical black pixel region 610 will be described. A control condition is set for each imaging region 600-ij. For example, control condition A is set for imaging regions 600-11 and 600-21, and control condition B is set for imaging regions 600-12 and 600-22. Similarly, control condition A is set for non-imaging regions 610-L1, 610-L3, 610-C1, and 610-C3, and control condition B is set for non-imaging regions 610-C2, 610-L4, 610-C2, and 610-C4.

[0087] Control conditions A and B are different control conditions. Specifically, for example, if control condition A is exposure time and control condition B is ISO sensitivity, control conditions A and B are different types of control conditions. Also, if control condition A is exposure time: 1 / 4 second and control condition B is exposure time: 1 / 250 second, control conditions A and B are different control conditions of the same type.

[0088] The dotted line with black circles at both ends indicates that the imaging region 600-ij in which the black circle is located corresponds to the non-imaging region 610-pq in the row direction in terms of black level correction. The imaging region 600-ij in which the black circle is located is referred to as the "reference imaging region 600-ij" for black level correction, and the non-imaging region 610-pq in which the black circle is located is referred to as the "reference non-imaging region 610-pq" for black level correction (the same applies to the dashed-dotted line with black circles at both ends described below).

[0089] Groups of pixels arranged in the row direction are selected at the same time by a row selection circuit or in units of blocks 202, and output pixel signals. Therefore, it is considered that there is a correlation between the reference source imaging region 600-ij and the reference destination non-imaging region 610-pq in terms of dark current, etc. For this reason, when performing black level correction on the output signal from the reference source imaging region 600-ij, high-precision black level correction according to the reference source imaging region 600-ij is possible by subtracting the output signal from the reference source imaging region 600-ij using the output signal from the reference destination non-imaging region 610-pq.

[0090] The dashed-dotted lines with black circles at both ends indicate that the imaging region 600-ij where the black circle is located corresponds to the non-imaging region 610-pq in the column direction in terms of black level correction. The pixel groups arranged in the column direction are connected to common column readout lines and each output an analog signal, which is converted into a digital signal by a common A / D converter.

[0091] Therefore, it is considered that there is a correlation between the reference source imaging region 600-ij and the reference destination non-imaging region 610-pq in terms of dark current, etc. For this reason, when performing black level correction on the output signal from the reference source imaging region 600-ij, by subtracting the output signal from the reference source imaging region 600-ij using the output signal from the reference destination non-imaging region 610-pq, it becomes possible to perform highly accurate black level correction according to the reference source imaging region 600-ij.

[0092] As described above, the number of non-imaging regions 610-pq is equal to or greater than the number of imaging regions 600-ij. Therefore, one imaging region 600-ij can correspond to one or more non-imaging regions 610-pq in black level correction. Note that, in black level correction, which output signal of the non-imaging region 610-pq in the row direction or the column direction for the imaging region 600-ij is used may be set in advance or may be set according to the control conditions of each imaging region 600-ij and each non-imaging region 610-pq. Alternatively, the larger, smaller, or average value of the output signals of the non-imaging regions 610-pq in both the row direction and the column direction for the imaging region 600-ij may be used.

[0093] Furthermore, in the above-described example, the "reference source imaging region 600-ij" and the "reference destination non-imaging region 610-pq" are selected at the same timing in units of row selection circuits or blocks 202, or are converted into digital signals by a common A / D converter, but this is not limiting. For example, a configuration may be adopted in which the "reference source imaging region 600-ij" and the "reference destination non-imaging region 610-pq" are not selected at the same timing in units of row selection circuits or blocks 202, and are not converted into digital signals by a common A / D converter.

[0094] Even with such a configuration, the "reference source imaging region 600-ij" and the "reference destination non-imaging region 610-pq" are controlled under the same control conditions, and therefore a correlation occurs between the "reference source imaging region 600-ij" and the "reference destination non-imaging region 610-pq" in terms of dark current, etc. Therefore, by subtracting the output signal from the reference source imaging region 600-ij using the output signal from the reference destination non-imaging region 610-pq, highly accurate black level correction according to the reference source imaging region 600-ij becomes possible.

[0095] Fig. 10 is an explanatory diagram showing a relationship 2 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region according to the first embodiment. Fig. 10 is also an example similar to Fig. 6, in which the number of non-imaging regions 610 is equal to or greater than the number of imaging regions 600. Fig. 10 shows a configuration in which non-imaging regions 610-C5, 610-L6, 610-C7, and 610-C8 are arranged in the row direction instead of the non-imaging regions 610-C2, 610-L4, 610-C2, and 610-C4 shown in Fig. 6.

[0096] Control condition A is set for non-imaging regions 610-C5 and 610-L6, and control condition B is set for non-imaging regions 610-C7 and 610-L8. The correspondence between the reference-source imaging region 600-ij and the reference-destination non-imaging region 610-pq is as indicated by the dotted line with black circles at both ends and the dashed-dotted line with black circles at both ends, as in Figure 6. Because the non-imaging regions 610-C5, 610-L6, 610-C7, and 610-C8 are arranged in only one row in the row direction, the area of ​​the imaging pixel region 600 can be made larger than in Figure 6.

[0097] Fig. 11 is an explanatory diagram showing a relationship 3 between the control conditions of the imaging pixel regions and the control conditions of the optical black pixel regions according to the first embodiment. Fig. 11 is also an example similar to Fig. 6, in which the number of non-imaging regions 610 is equal to or greater than the number of imaging regions 600. In Fig. 11, control condition A is set for imaging region 600-11, control condition B is set for imaging region 600-12, control condition C is set for imaging region 600-21, and control condition D is set for imaging region 600-22.

[0098] In addition, in FIG. 11, instead of the non-imaging regions 610-C2, 610-L4, 610-C2, 610-C4 shown in FIG. 6, a configuration is shown in which non-imaging regions 610-C5, 610-L6, 610-C7, 610-C8 are arranged in the row direction. Control condition A is set for non-imaging region 610-C5, control condition C is set for non-imaging region 610-L6, control condition B is set for non-imaging region 610-C5, and control condition D is set for non-imaging region 610-C8.

[0099] In addition, control condition A is set for non-imaging region 610-L1, control condition B is set for non-imaging region 610-L2, control condition C is set for non-imaging region 610-L3, and control condition D is set for non-imaging region 610-L4.

[0100] Control conditions A to D are different control conditions. Also, the correspondence relationship between the reference imaging region 600-ij and the destination non-imaging region 610-pq is the same as in FIG. 6, as shown by the double-ended black dotted line and the double-ended black dotted dash line.

[0101] Since the non-imaging regions 610-C5, 610-L6, 610-C7, 610-C8 are arranged in only one row in the row direction, the area of the imaging pixel region 600 can be increased compared to FIG. 6. Also, the number of different control conditions can be set up to the maximum number of imaging regions. In FIGS. 6, 10, and 11, the number of imaging regions 600 is 4 in each case, but in FIGS. 6 and 10, the number of different control conditions is 2, namely A and B.

[0102] On the other hand, in FIG. 11, 4 different control conditions, namely A to D, are set. Thus, it is possible to set the number of control conditions in proportion to the number of imaging regions 600. Therefore, various control conditions can be combined, and the freedom in shooting can be improved.

[0103] <Other examples of the PD-equipped optical black pixel 201-2> 12 is a block diagram showing another example of the PD-equipped optically black pixel 201-2 according to the first embodiment. In the PD-equipped optically black pixel 201-4, the output of the PD 104 is connected to the input of the PD 104. Note that the configuration is the same as that shown in FIGS. 7 and 8, except that the connection between the PD 104 and the transfer transistor 302 is short-circuited to the ground.

[0104] Therefore, charges resulting from photoelectric conversion are not generally accumulated in the PD 104. Even if charges are accumulated in the PD 104, they are not read out as pixel signals, but charges resulting from dark currents and the like are accumulated in the floating diffusion FD.

[0105] As described above, according to the first embodiment, it is possible to perform black level correction for each of the imaging regions 600-ij of the imaging pixel region 600 using the correlated non-imaging regions 610-pq outside the imaging pixel region 600. Therefore, it is possible to improve the accuracy of black level correction for each of the imaging regions 600-ij.

[0106] Also, consider a closed region 60 that includes all of the imaging pixels 6 of each imaging region 600-ij and is connected to the control lines (TX wiring 307, etc.) of that imaging region 600-ij, and is specified so that its outer edge has the shortest length. A non-imaging region 610-pq is located outside this closed region 60. This makes it possible to uniformly arrange the imaging pixels 6 inside each imaging region 600-ij. Therefore, so-called defective pixels are not generated, and high quality can be ensured for images generated by the imaging pixels 6 of each imaging region 600-ij. [Example]

[0107] In the second embodiment, the number of non-imaging areas in the optical black pixel area (described later) is smaller than the number of imaging areas in the imaging pixel area. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0108] <Relationship between control conditions for the imaging pixel area and the optical black pixel area> 13 is an explanatory diagram showing the relationship between the control conditions of the imaging pixel region 600 and the control conditions of the optical black pixel region according to the second embodiment. The optical black pixel region 610 is composed of a plurality of non-imaging regions 610-L1 to 610-L2 that do not capture an image of a subject. The plurality of non-imaging regions 610-L1 to 610-L2 are a group of non-imaging regions existing in the column direction. When the group of non-imaging regions is not distinguished, they are referred to as non-imaging regions 610-Lp.

[0109] The optical black pixel region 610 is adjacent to the outside of the imaging pixel region 600. In FIG. 13, for example, it is provided at the right end of the imaging pixel region 600. The optical black pixel region 610 may be located at at least one of the right end and the left end of the imaging pixel region 600. Furthermore, the number of non-imaging regions 610-Lp is smaller than the number of imaging regions 600-ij. In FIG. 13, the number of non-imaging regions 610-Lp is two, and the number of imaging regions 600-ij is four.

[0110] Next, the control conditions set for the imaging pixel region 600 and the optical black pixel region 610 will be described. A control condition is set for each imaging region 600-ij. For example, control condition A is set for imaging regions 600-11 and 600-12, and control condition B is set for imaging regions 600-21 and 600-22. Similarly, control condition A is set for non-imaging region 610-L1, and control condition B is set for non-imaging region 610-L2.

[0111] 6, the dotted line with black circles at both ends indicates that the imaging region 600-ij in which the black circle is located corresponds to the non-imaging region 610-pq in the row direction in black level correction. The imaging region 600-ij in which the black circle is located is referred to as the "reference imaging region 600-ij" for black level correction, and the non-imaging region 610-pq in which the black circle is located is referred to as the "reference non-imaging region 610-pq" for black level correction (the same applies to the dashed-dotted line with black circles at both ends described below).

[0112] Groups of pixels arranged in the row direction are selected at the same time by a row selection circuit or in units of blocks 202, and output pixel signals. Therefore, it is considered that there is a correlation between the reference source imaging region 600-ij and the reference destination non-imaging region 610-Lp in terms of dark current, etc. For this reason, when black level correction is performed on the output signal from the reference source imaging region 600-ij, the output signal from the reference source imaging region 600-ij is subtracted using the output signal from the reference destination non-imaging region 610-Lp, thereby making it possible to perform black level correction according to the reference source imaging region 600-ij.

[0113] As described above, the number of non-imaging regions 610-Lp is smaller than the number of imaging regions 600-ij. Therefore, one imaging region 600-ij can correspond to one or more non-imaging regions 610-Lp in black level correction. Furthermore, although black level correction is performed row by row, it may also be performed region by region. That is, each signal level of the imaging region 600-11 may be corrected using an average value of the signal output of the non-imaging region 610-L1.

[0114] <Correction table> 14 is an explanatory diagram illustrating an example of a correction table according to the second embodiment. The correction table 1400 is a table in which a correlation value 1405 is set for each combination of a reference source imaging area 1401, a reference source control condition 1402, a reference destination non-imaging area 1403, and a reference destination control condition 1404. The reference source imaging area 1401 stores the reference source imaging area 600-ij as a value. The reference source control condition 1402 stores the control condition of the reference source imaging area 600-ij as a value. The reference destination non-imaging area 1403 stores the non-imaging area 610-Lp that is the reference destination of the reference source imaging area 600-ij as a value. The reference destination control condition 1404 stores the control condition of the non-imaging area 610-Lp as a value.

[0115] The correlation value 1405 stores a value (correlation value r(ijX,LpY), where X is the reference source control condition 1402 and Y is the reference destination control condition 1404) indicating the correlation between the reference source imaging area 1401, to which the reference source control condition 1402 is set, and the reference destination non-imaging area 1403, to which the reference destination control condition 1404 is set.

[0116] The correlation value r(ijX,LpY) may be simply referred to as the correlation value r. The closer the correlation value r is to 1.0, the higher the correlation between the reference source imaging area 1401 and the reference destination non-imaging area 1403 is, and the farther the correlation value r is from 1.0, the lower the correlation between the reference source imaging area 1401 and the reference destination non-imaging area 1403 is.

[0117] Here, the output from the optical black pixel with PD or the output from the optical black pixel without PD in the reference non-imaging region 610-Lp is defined as Q, and the noise component after correction is defined as P. The relationship between P and Q is expressed by the following equation (1).

[0118] P = r × Q + b (1)

[0119] b is an adjustment value that is arbitrarily set and is determined for each image sensor 100. The calculation using the above formula (1) is performed, for example, by a signal processing unit 810, which will be described later.

[0120] The correlation value r tends to be close to 1.0 if the reference source imaging area 1401 and the reference destination non-imaging area 1403 are in the same row. For example, in Fig. 13, when the reference source imaging area 1401 is the imaging area 600-11 and the reference destination non-imaging area 1403 is the non-imaging area 610-L1, the correlation value r is closer to 1.0 than when the reference destination non-imaging area 1403 is the non-imaging area 610-L2. This is because when they are in the same row, they are read out at the same timing via the column readout lines.

[0121] Furthermore, the correlation value r tends to be closer to 1.0 as the reference source imaging area 1401 and the reference destination non-imaging area 1403 are closer to each other. For example, in Fig. 13, when the reference source imaging area 1401 is the imaging area 600-12 and the reference destination non-imaging area 1403 is the non-imaging area 610-L1, the correlation value r is closer to 1.0 than when the reference source imaging area 1401 is the imaging area 600-11. This is because it is considered that the closer the pixel positions are, the more similar their characteristics are.

[0122] Furthermore, the correlation value r is close to 1.0 when the referencing control condition 1402 and the referenced control condition 1404 are the same. Specifically, for example, when the referencing control condition 1402 and the referenced control condition 1404 are the same type of control conditions but have different values, the correlation value r is closer to 1.0 than when the referencing control condition 1402 and the referenced control condition 1404 are different types. This is because when the control conditions are the same type, the operating conditions of the referenced imaging area 1401 and the operating conditions of the referenced non-imaging area 1403 are the same.

[0123] Note that the target of noise component correction using the correlation value r may be limited to the reference source imaging area 1401 that is not adjacent to the reference destination non-imaging area 1403. For example, if the reference destination non-imaging area 1403 is the non-imaging area 610-L1, the reference source imaging area 1401 is the imaging area 600-11. In this case, the imaging area 600-12 is adjacent to the imaging area 610-L1, and therefore is not set as the reference source imaging area 1401. This limits the imaging areas to be corrected, thereby reducing the data in the correction table 1400.

[0124] <Circuit configuration of the imaging pixel area 600 and the optical black pixel area 610> Fig. 15 is a circuit diagram showing the circuit configuration of the imaging pixel region 600 in the column direction and the optical black pixel region 610. The circuit configuration of the imaging pixel region 600 and the optical black pixel region 610 in the row direction is the same as Fig. 11. In Figs. 11 and 15, the pixel 201 in the imaging pixel region 600 is referred to as the imaging pixel 201-1, and the pixel 201 in the optical black pixel region 610 is referred to as the optical black pixel with PD 201-2 and the optical black pixel without PD 201-3.

[0125] When control signals SEL_C, SEL_O1, and SEL_O2 from the drive circuit 811 are applied to the gates of the selection transistors 305, the selection transistors 305 output currents to the column read lines 701 to 703 at voltages amplified by the amplification transistors 304. The column read lines 1503-1 to 1503-4 in FIG. 15 correspond to the column read line 703 in FIG.

[0126] As described above, according to the second embodiment, it is possible to perform black level correction for each of the imaging regions 600-ij in the imaging pixel region 600 by using the non-imaging region 610-Lp that is correlated with the imaging region 600-ij. Therefore, it is possible to improve the accuracy of the black level correction for each of the imaging regions 600-ij. [Example]

[0127] Example 3 will be described. Example 2 shows an image sensor in which the same control conditions are set for the same row, but Example 3 shows an image sensor in which different control conditions are set for the same row. The same components as in Examples 1 and 2 are given the same reference numerals, and descriptions thereof will be omitted.

[0128] Fig. 16 is an explanatory diagram showing a relationship 1 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region according to Example 3. Fig. 17 is an explanatory diagram showing a relationship 2 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region according to Example 3. Figs. 16 and 17 are also similar to Fig. 13, and are examples in which the number of non-imaging regions 610 is smaller than the number of imaging regions 600.

[0129] In FIG. 16, control condition B is set for the imaging region 600-12 and the non-imaging region 610-L1, and control condition A is set for the imaging region 600-22 and the non-imaging region 610-L2.

[0130] 16 is different from Fig. 13 in that the control condition of non-imaging region 610-L1, which is the reference non-imaging region 1403 of imaging region 600-11, is A in Fig. 13, whereas the control condition of non-imaging region 610-L1 is B instead of A in Fig. 16. Similarly, the control condition of non-imaging region 610-L2, which is the reference non-imaging region 1403 of imaging region 600-21, is A in Fig. 13, whereas the control condition of non-imaging region 610-L2 is A instead of B in Fig. 16.

[0131] In addition, in FIG. 17, control condition B is set for imaging region 600-12 and non-imaging region 610-L1, control condition C is set for imaging region 600-21, and control condition D is set for imaging region 600-22 and non-imaging region 610-L2.

[0132] 17 is different from Fig. 13 in that the control condition of non-imaging region 610-L1, which is the reference non-imaging region 1403 of imaging region 600-11, is A in Fig. 13, whereas the control condition of non-imaging region 610-L1 is B instead of A in Fig. 17. Similarly, the control condition of non-imaging region 610-L2, which is the reference non-imaging region 1403 of imaging region 600-21, is A in Fig. 13, whereas the control condition of non-imaging region 610-L2 is D instead of A in Fig. 17.

[0133] Even in such a case, by appropriately setting the correlation value r, the signal processing unit 810 can calculate the black level correction with high accuracy using the above formula (1).

[0134] As described above, according to the third embodiment, it is possible to perform black level correction for each of the imaging regions 600-ij of the imaging pixel region 600 using the correlated non-imaging region 610-Lq outside the imaging pixel region 600. Therefore, it is possible to improve the accuracy of black level correction for each of the imaging regions 600-ij. [Example]

[0135] Example 4 will be described. In Example 2, an imaging element in which the same control conditions are set in the same row is shown, but in Example 4, an imaging element in which the same control conditions are set in the same column is shown. The same components as in Examples 1 to 3 are given the same reference numerals, and their description will be omitted.

[0136] <Relationship between control conditions for the imaging pixel area and the optical black pixel area> 18 is an explanatory diagram showing the relationship between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region according to the fourth embodiment. The optical black pixel region 610 is composed of a plurality of non-imaging regions 610-C1 to 610-C2 that do not capture an image of a subject. The plurality of non-imaging regions 610-C1 to 610-C2 are a group of non-imaging regions existing in the column direction. When the group of non-imaging regions is not distinguished, they are referred to as non-imaging regions 610-Cq.

[0137] The optical black pixel region 610 is adjacent to the outside of the imaging pixel region 600. In Fig. 18, for example, it is provided on the lower end side of the imaging pixel region 600. The optical black pixel region 610 may be located at least on either the upper end side or the lower end side of the imaging pixel region 600.

[0138] 18, the number of non-imaging regions 610-Cq is two, and the number of imaging regions 600-ij is four.

[0139] Next, the control conditions set for the imaging pixel region 600 and the optical black pixel region 610 will be described. A control condition is set for each imaging region 600-ij. For example, control condition A is set for imaging regions 600-11 and 600-21, and control condition B is set for imaging regions 600-12 and 600-22. Similarly, control condition A is set for non-imaging region 610-C1, and control condition B is set for non-imaging region 610-C2.

[0140] The dotted line with black circles at both ends indicates that the imaging region 600-ij in which the black circle is located corresponds to the non-imaging region 610-pq in the row direction in terms of black level correction. The imaging region 600-ij in which the black circle is located is referred to as the "reference imaging region 600-ij" for black level correction, and the non-imaging region 610-pq in which the black circle is located is referred to as the "reference non-imaging region 610-pq" for black level correction (the same applies to the dashed-dotted line with black circles at both ends described below).

[0141] The pixel groups arranged in the column direction are connected to a common column readout line and each output an analog signal, which is converted into a digital signal by a common A / D converter. Therefore, it is considered that there is (a high) correlation between the reference source imaging region 600-ij and the reference destination non-imaging region 610-Cq in terms of dark current, etc. For this reason, when correcting the black level of the output signal from the reference source imaging region 600-ij, by subtracting the output signal from the reference source imaging region 600-ij by the output signal from the reference destination non-imaging region 610-Cq, highly accurate black level correction according to the reference source imaging region 600-ij is possible.

[0142] As described above, the number of non-imaging regions 610-Cq is smaller than the number of imaging regions 600-ij. Therefore, one imaging region 600-ij can correspond to one or more non-imaging regions 610-Cq in terms of black level correction.

[0143] <Correction table> 19 is an explanatory diagram illustrating an example of a correction table according to the fourth embodiment. The correction table 1900 is a table in which a correlation value 1405 is set for each combination of a reference source imaging area 1401, a reference source control condition 1402, a reference destination non-imaging area 1403, and a reference destination control condition 1404. The reference destination non-imaging area 1403 stores, as a value, a non-imaging area 610-Cq that is a reference destination of the reference source imaging area 600-ij. The reference destination control condition 1404 stores, as a value, the control condition of the non-imaging area 610-Cq.

[0144] The correlation value 1405 stores a value (correlation value r(ijX,CqY), where X is the reference source control condition 1402 and Y is the reference destination control condition 1404) indicating the correlation between the reference source imaging area 1401, in which the reference source control condition 1402 is set, and the reference destination non-imaging area 1403, in which the reference destination control condition 1404 is set.

[0145] The correlation value r(ijX, CqY) may be simply referred to as the correlation value r. The closer the correlation value r is to 1.0, the higher the correlation between the reference source imaging area 1401 and the reference destination non-imaging area 1403 is, and the farther the correlation value r is from 1.0, the lower the correlation between the reference source imaging area 1401 and the reference destination non-imaging area 1403 is.

[0146] Here, the output from the optically black pixel with PD or the output from the optically black pixel without PD in the reference non-imaging region 610-Cq is defined as Q, and the noise component after correction is defined as P. The relationship between P and Q is expressed by the above formula (1).

[0147] The correlation value r is close to 1.0 when the reference source imaging area 1401 and the reference destination non-imaging area 1403 are in the same column. For example, in Fig. 18, when the reference source imaging area 1401 is the imaging area 600-11 and the reference destination non-imaging area 1403 is the non-imaging area 610-C1, the correlation value r is closer to 1.0 than when the reference destination non-imaging area 1403 is the non-imaging area 610-C2. This is because when they are in the same column, they are read out using the same column readout line.

[0148] Furthermore, the closer the reference source imaging area 1401 and the reference destination non-imaging area 1403 are to each other, the closer the correlation value r becomes to 1.0. For example, in Fig. 18, when the reference source imaging area 1401 is the imaging area 600-21 and the reference destination non-imaging area 1403 is the non-imaging area 610-C1, the correlation value r becomes closer to 1.0 compared to when the reference source imaging area 1401 is the imaging area 600-11. This is because it is considered that the closer the pixel positions are, the more similar their characteristics are.

[0149] Note that the target of noise component correction using the correlation value r may be limited to the reference source imaging area 1401 that is not adjacent to the reference destination non-imaging area 1403. For example, when the reference destination non-imaging area 1403 is the non-imaging area 610-C1, the reference source imaging area 1401 is the imaging area 600-11.

[0150] In this case, since the imaging area 600-21 is adjacent to the imaging area 610-C1, it is not set as the reference imaging area 1401. This limits the imaging areas to be corrected, and the data in the correction table 1900 becomes smaller.

[0151] <Circuit configuration of the imaging pixel area 600 and the optical black pixel area 610> 20 is a circuit diagram showing the circuit configuration of the row-direction imaging pixel area 600 and optical black pixel area 610. The circuit configuration of the column-direction imaging pixel area 600 and optical black pixel area 610 is the same as that in FIG.

[0152] When control signals SEL_C, SEL_O1, and SEL_O2 from a drive circuit 811 are applied to the gates of the selection transistors 305, the selection transistors 305 output currents to the column readout lines 701 to 703 at voltages amplified by the amplification transistors 304. The column readout lines 701-1 to 701-4 in FIG. 10 correspond to the column readout lines 702 and 703 in FIG.

[0153] As described above, according to the fourth embodiment, it is possible to perform black level correction for each of the imaging regions 600-ij of the imaging pixel region 600 using the correlated non-imaging region 610-Cq outside the imaging pixel region 600. Therefore, it is possible to improve the accuracy of the black level correction for each of the imaging regions 600-ij. [Example]

[0154] Example 5 will be described. Example 4 shows an imaging element in which the same control conditions are set for the same column, but Example 5 shows an imaging element in which different control conditions are set for the same column. The same components as in Examples 1 to 4 are given the same reference numerals, and their description will be omitted.

[0155] Fig. 21 is an explanatory diagram showing a relationship 1 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region according to Example 5. Fig. 22 is an explanatory diagram showing a relationship 2 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region according to Example 5. Figs. 21 and 22 are also similar to Fig. 18, and are examples in which the number of non-imaging regions 610 is smaller than the number of imaging regions 600.

[0156] In FIG. 21, control condition B is set for imaging region 600-21 and non-imaging region 610-C1, and control condition A is set for imaging region 600-22 and non-imaging region 610-C2.

[0157] 18 is that in Fig. 18, the control condition of non-imaging region 610-C1, which is the reference non-imaging region 1403 of imaging region 600-11, is A, whereas in Fig. 21, the control condition of non-imaging region 610-C1 is B instead of A. Similarly, in Fig. 18, the control condition of non-imaging region 610-C2, which is the reference non-imaging region 1403 of imaging region 600-12, is B, whereas in Fig. 21, the control condition of non-imaging region 610-C2 is A instead of B.

[0158] In FIG. 22, control condition B is set for imaging region 600-21 and non-imaging region 610-C1, control condition C is set for imaging region 600-12, and control condition D is set for imaging region 600-22 and non-imaging region 610-C2.

[0159] 18 is that in Fig. 18, the control condition of non-imaging region 610-C1, which is the reference non-imaging region 1403 of imaging region 600-11, is A, whereas in Fig. 22, the control condition of non-imaging region 610-C1 is B instead of A. Similarly, in Fig. 18, the control condition of non-imaging region 610-C2, which is the reference non-imaging region 1403 of imaging region 600-12, is B, whereas in Fig. 22, the control condition of non-imaging region 610-C2 is D instead of B.

[0160] Even in such a case, by appropriately setting the correlation value r, the signal processing unit 810 can perform black level correction with high precision using the above equation (1).

[0161] As described above, according to the fifth embodiment, it is possible to perform black level correction for each of the imaging regions 600-ij of the imaging pixel region 600 using the correlated non-imaging region 610-Cq outside the imaging pixel region 600. Therefore, it is possible to improve the accuracy of the black level correction for each of the imaging regions 600-ij. [Example]

[0162] In the sixth embodiment, the number of non-imaging regions in the optical black pixel region (described later) is smaller than the number of imaging regions in the imaging pixel region. The same components as those in the first to fifth embodiments are denoted by the same reference numerals, and the description thereof will be omitted.

[0163] <Relationship between the control conditions of the imaging pixel region 600 and the control conditions of the optical black pixel region 610> The relationship between the control conditions of the imaging pixel region 600 and the control conditions of the optical black pixel region 610 according to the sixth embodiment will be described with reference to Figs. 23 and 24. This relationship is such that the optical black pixel region 610 is provided within the imaging pixel region 600, and the number of non-imaging regions within the optical black pixel region 610 is smaller than the number of imaging regions within the imaging pixel region 600. Fig. 24 will be described focusing on differences from Fig. 23, and therefore descriptions of the same parts as Fig. 23 will be omitted.

[0164] FIG. 23 is an explanatory diagram showing a relationship 1 between the control conditions of the imaging pixel region 600 and the control conditions of the optical black pixel region according to the sixth embodiment. The imaging region is, for example, a collection of one or more blocks 202. In FIG. 23, for the sake of simplicity, the imaging pixel region 600 is configured by four rows and four columns of imaging regions 600-11 to 600-14, 600-21 to 600-24, 600-31 to 600-34, and 600-41 to 600-44. However, the imaging pixel region 600 may be configured by m rows and n columns (m and n are integers equal to or greater than 1, but there may be two or more imaging regions 600) other than four rows and four columns. When there is no need to distinguish between the imaging regions 600-11 to 600-14, 600-21 to 600-24, 600-31 to 600-34, and 600-41 to 600-44, they are referred to as imaging region 600-ij.

[0165] The optical black pixel region 610 is composed of multiple non-imaging regions 610-11, 610-13, 610-22, 610-24, 610-31, 610-33, 610-42, and 610-44 that do not capture an image of a subject. When the non-imaging regions 610-11, 610-134, 610-122, 610-24, 610-31, 610-33, 610-42, and 610-44 are not distinguished from one another, they are referred to as non-imaging regions 610-ij. The non-imaging regions 610-ij are provided in the imaging region 600-ij, which is located in the i-th row and j-th column.

[0166] The positional relationship between the imaging region 600-ij and the non-imaging region 610-ij will be described in detail. As described above, each imaging region 600-ij has a configuration in which imaging pixels 6 are arranged two-dimensionally. The imaging pixels 6 of each imaging region 600-ij have a configuration similar to that of block 202 described with reference to FIG. 2, for example, and each imaging region 600-ij can be controlled under different control conditions. The configuration shown in Example 6 includes an imaging region 600-ij with a non-imaging region 610-ij arranged therein and an imaging region 600-ij without a non-imaging region 610-ij arranged therein.

[0167] In the configuration shown in Fig. 23, consider a closed region 60 that is specified to include all of the imaging pixels 6 in the imaging region 600-11 and that are connected to the control lines (TX wiring 307, etc.) of the imaging region 600-11, and that has the shortest outer edge. In this case, a non-imaging region 610-11 is arranged inside the closed region 60. Also, in the configuration shown in Fig. 23, consider a closed region 60 that is specified to include all of the imaging pixels 6 in the imaging region 600-121 and that are connected to the control lines (TX wiring 307, etc.) of the imaging region 600-12, and that has the shortest outer edge. In this case, no non-imaging region 610-ij is arranged inside the closed region 60.

[0168] Thus, the configuration shown in FIG. 23 includes imaging areas (imaging area 600-11, imaging area 600-13, imaging area 600-22, etc.) in which the non-imaging area 610-ij is arranged, and imaging areas (imaging area 600-12, imaging area 600-14, imaging area 600-21, etc.) in which the non-imaging area 610-ij is not arranged.

[0169] With this configuration, in the imaging region 600-ij where the non-imaging region 610-ij is arranged, high-precision black level correction is performed due to the strong correlation in terms of dark current and the like between the "reference-source imaging region 600-ij" and the "reference-destination non-imaging region 610-pq." Furthermore, in the imaging region 600-ij where the non-imaging region 610-ij is not arranged, black level correction is performed using the output signal of the non-imaging region 610-ij arranged in the adjacent imaging region 600-ij. This prevents so-called defective pixels from occurring. Therefore, it is possible to ensure high quality in the image generated by the imaging pixels 6 of the imaging region 600-ij.

[0170] 23, the imaging regions 600-ij including the optical black pixel regions 610 are arranged discretely. The imaging regions 600-ij including the optical black pixel regions 610 are arranged, for example, in a staggered pattern. The optical black pixel regions 610 are arranged, for example, in a staggered pattern within the imaging pixel region 600. As long as the number of imaging regions including non-imaging regions 610-ij is smaller than the number of imaging regions 600-ij, the arrangement is not limited to a staggered arrangement.

[0171] Each non-imaging region 610-ij includes a group of optical black pixels with a PD and a group of optical black pixels without a PD. The optical black pixel region 610 has a group of optical black pixels with a PD and a group of optical black pixels without a PD. The number of imaging regions including the non-imaging region 610-ij is smaller than the number of imaging regions 600-ij. In FIG. 23, there are eight non-imaging regions 610-ij and sixteen imaging regions 600-ij.

[0172] Next, the control conditions set for the imaging pixel region 600 and the optical black pixel region 610 will be described. Control conditions are set for each imaging region 600-ij and each non-imaging region 610-ij. The control conditions for the non-imaging region 610-ij are the same as the control conditions for the imaging region 600-ij that includes the non-imaging region 610-ij. For example, the control condition for the non-imaging region 610-11 is B, and the control condition for the imaging region 600-11 that includes the non-imaging region 610-11 is also B.

[0173] Although not indicated by the dotted line with black circles at both ends, the non-imaging region 610-ij regards the imaging region 600-ij that includes the non-imaging region 610-ij as the "reference imaging region 600-ij." Therefore, for example, the non-imaging region 610-11 is the reference imaging region of the imaging region 600-11 that includes the non-imaging region 610-11, and is also the reference imaging region of the imaging region 600-12 that does not include the non-imaging region 610-11.

[0174] Groups of pixels arranged in the row direction are selected at the same time by a row selection circuit or in units of blocks 202, and output pixel signals. Therefore, it is considered that there is a correlation between the reference source imaging region 600-ij and the reference destination non-imaging region 610-ij in terms of dark current, etc. For this reason, when performing black level correction on the output signal from the reference source imaging region 600-ij, high-precision black level correction according to the reference source imaging region 600-ij is possible by subtracting the output signal from the reference destination non-imaging region 610-ij from the output signal from the reference source imaging region 600-ij.

[0175] Furthermore, a dashed-dotted line with black circles at both ends indicates that the imaging region 600-ij in which the black circle is located refers to the control conditions of the non-imaging region 610-ij in the column direction. Although not indicated by the dashed-dotted line with black circles at both ends, the non-imaging region 610-ij considers the imaging region 600-ij that includes the non-imaging region 610-ij to be the "reference imaging region 600-ij." Therefore, for example, the non-imaging region 610-31 is the reference imaging region of the imaging region 600-31 that includes the non-imaging region 610-31, and is also the reference imaging region of the imaging region 600-21 that does not include the non-imaging region 610-31.

[0176] The pixel groups arranged in the column direction are connected to a common column readout line and each output an analog signal in units of block 202, which is converted into a digital signal by a common A / D converter. Therefore, it is considered that there is a correlation between the reference source imaging region 600-ij and the reference destination non-imaging region 610-ij in terms of dark current, etc. For this reason, when correcting the black level of the output signal from the reference source imaging region 600-ij, subtracting the output signal from the reference source imaging region 600-ij using the output signal from the reference destination non-imaging region 610-ij enables highly accurate black level correction according to the reference source imaging region 600-ij.

[0177] As described above, the number of non-imaging regions 610-ij is smaller than the number of imaging regions 600-ij. Therefore, one non-imaging region 610-ij can correspond to one or more imaging regions 600-ij in black level correction. Whether the non-imaging region 610-ij in the row direction or the column direction is to be referenced for the imaging region 600-ij may be set in advance or may be set according to the control conditions of each imaging region 600-ij and each non-imaging region 610-pq. Alternatively, the larger, smaller, or average value of the output signals of the non-imaging regions 610-pq in both the row direction and the column direction for the imaging region 600-ij may be used.

[0178] Furthermore, by providing the non-imaging region 600-ij within the imaging region 600-ij, it is possible to prevent the imaging element from becoming larger, since the optical black pixel region does not need to be arranged outside the imaging pixel region 600. Furthermore, since the optical black pixel region does not need to be arranged outside the imaging pixel region 600, the area of ​​the imaging pixel region 600 can be increased accordingly.

[0179] Fig. 24 is an explanatory diagram showing a relationship 2 between the control conditions of the imaging pixel region 600 and the control conditions of the optical black pixel region 610 according to Example 6. Like Fig. 23, Fig. 24 also shows an example in which the number of non-imaging regions 610-ij is equal to or greater than the number of imaging regions 600-ij. In Fig. 24, the four imaging regions 600-22, 600-23, 600-32, and 600-33 located in the center of the imaging pixel region 600 are not provided with non-imaging regions 610-ij.

[0180] The reason is that the main subject image is reflected in the center of the imaging pixel area 600, and there are more image plane phase difference detection pixels that focus on the main subject in the center than in the surrounding imaging areas 600-11 to 600-14, 600-21, 600-24, 600-31, 600-34, and 600-41 to 600-44.

[0181] The non-image capturing areas 610-ij become defective pixels when generating an image, requiring interpolation, which is likely to result in degradation of image quality. Therefore, it is possible to either not place the non-image capturing areas 610-ij near the central area where it is thought that the main subject is likely to be present, or to place more non-image capturing areas 610-ij outside the central area than in the central area. Furthermore, it is also possible to increase the number of non-image capturing areas 610-ij as the distance from the central area increases.

[0182] The non-imaging region 610-ij may be provided on an edge of the imaging pixel region 600 (outside the imaging region 600-ij), or in an imaging region 600-ij closer to the edge than the center of the imaging pixel region 600. Furthermore, the non-imaging region 610-ij is not limited to being provided in the center of the imaging pixel region 600, and may be provided in an imaging region 600-ij in which the number of image plane phase difference detection pixels is a predetermined number or less, or in an imaging region 600-ij in which the number of image plane phase difference detection pixels is relatively small.

[0183] <Circuit configuration of the imaging pixel area 600 and the optical black pixel area 610> The circuit configuration of the imaging pixel area 600 and the optical black pixel area 610 in the row direction is as shown in FIG. 9, and the circuit configuration of the imaging pixel area 600 and the optical black pixel area 610 in the column direction is as shown in FIG.

[0184] The signal processing unit 710 may interpolate the signal at the position of the optically black pixel 201-3 without a PD using signals output from imaging pixels 201-1 present around the optically black pixel 201-3 without a PD. The interpolation method used by the signal processing unit 710 may be an interpolation method using median processing, an interpolation method based on a gradient, or an adaptive color plane interpolation method. The same applies to the image plane phase difference detection pixel.

[0185] <Correction table> 25 is an explanatory diagram illustrating an example of a correction table according to Example 6. A correction table 2500 is a table in which a correlation value 1405 is set for each combination of a reference source imaging area 1401, a reference source control condition 1402, a reference destination non-imaging area 1403, and a reference destination control condition 1404.

[0186] The reference source imaging area 1401 stores the reference source imaging area 600-ij as a value. The reference source control condition 1402 stores the control condition of the reference source imaging area 600-ij as a value. The reference destination non-imaging area 1403 stores the non-imaging area 610-Lp that is the reference destination of the reference source imaging area 600-ij as a value. The reference destination control condition 1404 stores the control condition of the non-imaging area 610-ij as a value.

[0187] The correlation value 1405 stores a value (correlation value r(ijX, ijY), where X is the reference source control condition 1402 and Y is the reference destination control condition 1404) indicating the correlation between the reference source imaging area 1401, to which the reference source control condition 1402 is set, and the reference destination non-imaging area 1403, to which the reference destination control condition 1404 is set.

[0188] The correlation value r(ijX, ijY) may be simply referred to as the correlation value r. The closer the correlation value r is to 1.0, the higher the correlation between the reference source imaging area 1401 and the reference destination non-imaging area 1403 is, and the farther the correlation value r is from 1.0, the lower the correlation between the reference source imaging area 1401 and the reference destination non-imaging area 1403 is.

[0189] Here, the output from the optical black pixel with PD or the output from the optical black pixel without PD in the reference non-imaging region 610-ij is defined as Q, and the noise component after correction is defined as P. The relationship between P and Q is expressed by the above formula (1).

[0190] The correlation value r is close to 1.0 when the reference non-imaging region 1403 includes the reference source imaging region 1401. For example, in Fig. 23, when the reference source imaging region 1401 is the imaging region 600-11 and the reference non-imaging region 1403 is the non-imaging region 610-11, the correlation value r is closer to 1.0 than when the reference non-imaging region 1403 is the non-imaging region 610-12. This is because when the reference non-imaging region 1403 includes the reference source imaging region 1401, they are read out using the same column readout line.

[0191] The correlation value r is close to 1.0 if the reference source imaging area 1401 and the reference destination non-imaging area 1403 are in the same row. For example, in Fig. 23, when the reference source imaging area 1401 is the imaging area 600-11 and the reference destination non-imaging area 1403 is the non-imaging area 610-11, the correlation value r is closer to 1.0 than when the reference destination non-imaging area 1403 is the non-imaging area 610-22. This is because when they are in the same row, they are read out at the same timing via the column readout lines.

[0192] Furthermore, the closer the reference source imaging area 1401 and the reference destination non-imaging area 1403 are to each other, the closer the correlation value r becomes to 1.0. For example, in Fig. 23, when the reference source imaging area 1401 is the imaging area 600-11 and the reference destination non-imaging area 1403 is the non-imaging area 610-12, the correlation value r becomes closer to 1.0 compared to when the reference source imaging area 1401 is the imaging area 600-14. This is because it is considered that the closer the pixel positions are, the more similar their characteristics are.

[0193] Furthermore, the correlation value r is closer to 1.0 if the referencing control condition 1402 and the referenced control condition 1404 are the same. Specifically, for example, if the referencing control condition 1402 and the referenced control condition 1404 are control conditions of the same type but different values, the correlation value r is closer to 1.0 than if the referencing control condition 1402 and the referenced control condition 1404 are of different types. This is because it is considered that the more similar the control conditions are, the more similar the operating conditions of the referenced imaging area 1401 and the referenced non-imaging area 1403 will be.

[0194] As described above, according to the seventh embodiment, it is possible to perform black level correction for each of the imaging regions 600-ij of the imaging pixel region 600 by using the correlated non-imaging regions 610-pq outside the imaging pixel region 600. Therefore, it is possible to improve the accuracy of the black level correction for each of the imaging regions 600-ij. [Example]

[0195] <Relationship between control conditions for the imaging pixel area and the optical black pixel area> Next, a description will be given of the relationship between the control conditions for the imaging pixel area and the control conditions for the optical black pixel area according to Example 7. Example 7 is configured such that an optical black pixel area 610 is provided outside the imaging pixel area 600 in Example 6. The same parts as in Example 6 are given the same reference numerals, and their description will be omitted.

[0196] 26 is an explanatory diagram showing the relationship between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region. The optical black pixel region 610 exists both inside and outside the imaging pixel region 600. First, the optical black pixel region 610 existing inside the imaging pixel region 600 (hereinafter referred to as the internal optical black pixel region 610) will be described.

[0197] The internal optical black pixel region 610 is composed of multiple internal non-imaging regions 610-11 to 610-14, 610-21, 610-24, 610-31, 610-34, 610-41, and 610-44 that do not capture an image of a subject. When the internal non-imaging regions 610-11 to 610-14, 610-21, 610-24, 610-31, 610-34, 610-41, and 610-44 are not distinguished from one another, they are referred to as internal non-imaging regions 610-ij. The internal non-imaging regions 610-ij are provided in the imaging region 600-ij, which is located in the i-th row and j-th column.

[0198] 26 shows an imaging region 600 in which internal optical black pixel regions 610 are arranged, but the internal optical black pixel regions 610 are arranged, for example, in a staggered pattern within the imaging pixel region 600. As long as the number of internal non-imaging regions 610-ij is smaller than the number of imaging regions 600-ij, the arrangement is not limited to a staggered pattern.

[0199] One internal non-imaging region 610-ij includes a group of optical black pixels with PD and a group of optical black pixels without PD. The optical black pixel region 610 has a group of optical black pixels with PD and a group of optical black pixels without PD. The group of optical black pixels with PD is a collection of optical black pixels with PD. The optical black pixels with PD are black pixels that have PD 104. Specifically, for example, the optical black pixels with PD are pixels that have a light-shielding layer that blocks the incidence of subject light.

[0200] 26, the number of internal non-imaging regions 610-ij is 12, and the number of imaging regions 600-ij is 16. In FIG.

[0201] Next, the optical black pixel region 610 that exists outside the imaging pixel region 600 (hereinafter referred to as the external optical black pixel region 610) will be described.

[0202] The external optical black pixel region 610 is composed of multiple external non-imaging regions 610-L1 to 610-L2 and 610-C1 to 610-C2 that do not capture an image of a subject. The multiple external non-imaging regions 610-L1 to 610-L2 (two in FIG. 26 as an example) are a group of external non-imaging regions arranged in the column direction. When the group of external non-imaging regions arranged in the column direction is not distinguished, they are referred to as external non-imaging regions 610-Lp.

[0203] The multiple external non-imaging regions 610-C1 to 610-C2 (two in FIG. 26 as an example) are a group of external non-imaging regions existing in the row direction. When the group of non-imaging regions existing in the row direction is not distinguished, they are referred to as external non-imaging region 610-Cq. When the multiple external non-imaging regions 610-L1 to 610-L2 and 610-C1 to 610-C2 are not distinguished, they are referred to as external non-imaging region 610-pq. Like the internal non-imaging region 610-ij, one external non-imaging region 610-pq includes a group of optical black pixels with PD and a group of optical black pixels without PD.

[0204] Like the internal optical black pixel region 610, the external optical black pixel region 610 is adjacent to the outside of the imaging pixel region 600. In Fig. 26, for example, the external optical black pixel region 610 is provided at the right end and bottom end of the imaging pixel region 600. The external optical black pixel region 610 may be located at at least one of the top end, bottom end, right end, and left end of the imaging pixel region 600.

[0205] Like the internal optical black pixel region 610, the external optical black pixel region 610 has a group of optical black pixels with PD and a group of optical black pixels without PD. The number of external non-imaging regions 610-pq is, for example, equal to or greater than the number of imaging regions 600-ij that do not have internal non-imaging regions 600-ij. In FIG. 26 , the number of external non-imaging regions 610-pq is four, and the number of imaging regions 600-ij is four.

[0206] Next, we will explain the control conditions set for the imaging pixel region 600 and the optical black pixel region 610. Control conditions are set for each imaging region 600-ij, each internal non-imaging region 610-ij, and each external non-imaging region 610-pq.

[0207] For example, control condition B is set to imaging regions 600-11 to 600-14, 600-21, 600-24, 600-31, 600-34, and 600-11 to 600-14, and control condition A is set to imaging regions 600-22, 600-23, 600-32, and 600-33.

[0208] The control condition of the internal non-imaging region 610-ij is the same as the control condition of the imaging region 600-ij including the internal non-imaging region 610-ij. For example, the control condition of the internal non-imaging region 610-11 is B, and the control condition of the imaging region 600-11 including the internal non-imaging region 610-11 is also B. For example, the control condition A is set for the external non-imaging regions 610-L1, 610-L2, 610-C1, and 610-C2.

[0209] The dotted line with black circles at both ends indicates that the imaging region 600-ij in which the black circle is located corresponds to the non-imaging region 610-pq in the row direction in terms of black level correction. The imaging region 600-ij in which the black circle is located is referred to as the "reference imaging region 600-ij" for black level correction, and the non-imaging region 610-pq in which the black circle is located is referred to as the "reference non-imaging region 610-pq" for black level correction (the same applies to the dashed-dotted line with black circles at both ends described below).

[0210] Although not indicated by a dotted line or a dashed line with black circles at both ends, the internal non-imaging region 610-ij regards the imaging region 600-ij including the internal non-imaging region 610-ij as the "reference imaging region 600-ij." Therefore, for example, the internal non-imaging region 610-11 is the reference imaging region of the imaging region 600-11 including the internal non-imaging region 610-11.

[0211] Groups of pixels arranged in the row direction are selected at the same time by a row selection circuit or by blocks 202, and output pixel signals. Therefore, it is considered that there is a correlation between the reference source imaging region 600-ij and the reference destination external non-imaging region 610-Lp in terms of dark current, etc. The same is true between the reference source imaging region 600-ij and the reference destination internal non-imaging region 610-ij. For this reason, when performing black level correction on the output signal from the reference source imaging region 600-ij, high-precision black level correction according to the reference source imaging region 600-ij is possible by subtracting the output signal from the reference destination external non-imaging region 610-Lp or the reference destination internal non-imaging region 610-ij from the output signal from the reference source imaging region 600-ij.

[0212] Moreover, the dashed-dotted line with black circles at both ends indicates that the imaging region 600-ij in which the black circle is located in the column direction refers to the control conditions of the external non-imaging region 610-Cq.

[0213] The pixel groups arranged in the column direction are connected to a common column readout line and each output an analog signal, which is converted to a digital signal by a common A / D converter. Therefore, it is considered that there is a correlation between the reference source imaging region 600-ij and the reference destination external non-imaging region 610-Cq in terms of dark current, etc. The same is true between the reference source imaging region 600-ij and the reference destination internal non-imaging region 610-ij.

[0214] Therefore, when performing black level correction on the output signal from the reference source imaging area 600-ij, the output signal from the reference source imaging area 600-ij is subtracted using the output signal from the reference destination external non-imaging area 610-Cq or the reference destination internal non-imaging area 610-ij, thereby enabling highly accurate black level correction according to the reference source imaging area 600-ij.

[0215] As described above, the number of internal non-imaging regions 610-ij is smaller than the number of imaging regions 600-ij. Therefore, one internal non-imaging region 610-ij can correspond to one or more imaging regions 600-ij in black level correction. Whether the external non-imaging regions 610-pq in the row direction or the column direction are to be referenced for the imaging region 600-ij may be set in advance or may be set according to the control conditions of each imaging region 600-ij and each non-imaging region 610-pq. Alternatively, the larger, smaller, or average value of the output signals of the non-imaging regions 610-pq in both the row direction and the column direction for the imaging region 600-ij may be used.

[0216] 26, each of the imaging areas 600-ij at the center of the imaging pixel area 600 uses the external non-imaging area 610-pq as a reference, and each of the imaging areas 600-ij around the center uses the internal non-imaging area 610-ij present in the imaging area 600-ij as a reference. The reason for this is that the image of the main subject is reflected in the center of the effective imaging area 600, and there are more image plane phase difference detection pixels that focus on the main subject than in the surrounding imaging areas 600-11 to 600-14, 600-21, 600-24, 600-31, 600-34, and 600-41 to 600-44.

[0217] <Correction table> 27 is a diagram illustrating an example of a correction table according to Example 7. The correction table 2700 is a table in which a correlation value 1405 is set for each combination of a reference source imaging area 1401, a reference source control condition 1402, a reference destination non-imaging area 1403, and a reference destination control condition 1404.

[0218] The reference source imaging area 1401 stores the reference source imaging area 600-ij as a value. The reference source control condition 1402 stores the control condition of the reference source imaging area 600-ij as a value. The reference destination non-imaging area 1403 stores the internal non-imaging area 610-ij or the external non-imaging area 610-pq that is the reference destination of the reference source imaging area 600-ij as a value. The reference destination control condition 1404 stores the control condition of the internal non-imaging area 610-ij or the external non-imaging area 610-pq as a value.

[0219] The correlation value 1405 stores a value indicating the correlation between the reference source imaging area 1401, in which the reference source control condition 1402 is set, and the reference destination non-imaging area 1403, in which the reference destination control condition 1404 is set (correlation value r(ijX, ijY), correlation value r(ijX, LpY), or correlation value r(ijX, CqY). X is the reference source control condition 1402, and Y is the reference destination control condition 1404).

[0220] The correlation value r(ijX, ijY), correlation value r(ijX, LpY), or correlation value r(ijX, CqY) may be simply referred to as the correlation value r. The closer the correlation value r is to 1.0, the higher the correlation between the reference source imaging area 1401 and the reference destination non-imaging area 1403, and the farther the correlation value r is from 1.0, the lower the correlation between the reference source imaging area 1401 and the reference destination non-imaging area 1403.

[0221] Here, the output signal from the reference destination internal non-imaging region 610-ij or the reference destination external non-imaging region 610-pq is denoted by Q, and the corrected noise component is denoted by P. The relationship between P and Q is expressed by the above formula (1).

[0222] The correlation value r is close to 1.0 when the reference non-imaging region 1403 includes the reference source imaging region 1401. For example, in Fig. 26, when the reference source imaging region 1401 is the imaging region 600-11, if the reference non-imaging region 1403 is the non-imaging region 610-11, the correlation value r is closer to 1.0 than when the reference non-imaging region 1403 is the non-imaging region 610-12. This is because when the reference non-imaging region 1403 includes the reference source imaging region 1401, they are read out using the same column readout line.

[0223] The correlation value r is close to 1.0 if the reference source imaging area 1401 and the reference destination non-imaging area 1403 are in the same row. For example, in Fig. 26, when the reference source imaging area 1401 is the imaging area 600-11 and the reference destination non-imaging area 1403 is the non-imaging area 610-11, the correlation value r is closer to 1.0 than when the reference destination non-imaging area 1403 is the non-imaging area 610-22. This is because when they are in the same row, they are read out at the same timing via the column readout lines.

[0224] Furthermore, the closer the reference source imaging area 1401 and the reference destination non-imaging area 1403 are to each other, the closer the correlation value r becomes to 1.0. For example, in Fig. 26, when the reference source imaging area 1401 is the imaging area 600-11 and the reference destination non-imaging area 1403 is the non-imaging area 610-12, the correlation value r becomes closer to 1.0 compared to when the reference source imaging area 1401 is the imaging area 600-14. This is because it is considered that the closer the pixel positions are, the more similar their characteristics are.

[0225] Furthermore, the correlation value r is closer to 1.0 if the referencing control condition 1402 and the referenced control condition 1404 are the same. Specifically, for example, if the referencing control condition 1402 and the referenced control condition 1404 are control conditions of the same type but different values, the correlation value r is closer to 1.0 than if the referencing control condition 1402 and the referenced control condition 1404 are of different types. This is because it is considered that the more similar the control conditions are, the more similar the operating conditions of the referenced imaging area 1401 and the referenced non-imaging area 1403 will be.

[0226] As described above, according to the seventh embodiment, it is possible to perform black level correction for each of the imaging regions 600-ij of the imaging pixel region 600 by using the correlated non-imaging regions 610-pq outside the imaging pixel region 600. Therefore, it is possible to improve the accuracy of the black level correction for each of the imaging regions 600-ij.

[0227] The present invention is not limited to the above-mentioned contents, and may be any combination of these. Furthermore, other embodiments that are conceivable within the scope of the technical idea of ​​the present invention are also included in the scope of the present invention. [Explanation of symbols]

[0228] 100 imaging element, 102 color filter, 104 PD, 201 pixel, 201-1 imaging pixel, 201-2 optical black pixel with PD, 201-2 optical black pixel without PD, 202 block, 600 imaging pixel area, 600-ij imaging area, 610 optical black pixel area, 610-pq non-imaging area, 900 light-shielding layer, 910 signal processing unit, 911 drive circuit, 912 control unit

Claims

[Claim 1] an imaging region including a first photoelectric conversion unit that receives light from an optical system and converts it into an electric charge and a first circuit unit connected to the first photoelectric conversion unit, a plurality of first pixels arranged in a first direction and a second direction intersecting the first direction, first control lines connected to the plurality of first pixels and outputting signals that control the plurality of first pixels, and first output lines connected to the plurality of first pixels and outputting signals generated by the plurality of first pixels; a plurality of light-shielded pixel regions including a plurality of second pixels, each including a light-shielded second photoelectric conversion unit and a second circuit unit connected to the second photoelectric conversion unit, and arranged in the first direction and the second direction; second control lines connected to the plurality of second pixels and outputting signals for controlling the second pixels; and second output lines, different from the first output lines, connected to the plurality of second pixels and outputting signals generated by the plurality of second pixels; the light-shielded pixel region is disposed outside a region including all of the first pixels in the imaging region that are connected to the first control lines in the imaging region, an imaging pixel area having a plurality of the imaging areas, wherein different control conditions can be set for each of the plurality of imaging areas; an optical black pixel area in which the same control conditions as those of a reference imaging area can be set in each of the plurality of light-shielding pixel areas; An imaging element having

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