Imaging element and imaging device

Abstract

An imaging element is provided with: a plurality of imaging regions each having: a plurality of first pixels each including a first photoelectric conversion unit that receives light from an optical system and converts the light into an electric charge, and a first circuit unit connected to the first photoelectric conversion unit; the first electrode and the second electrode are arranged in a first direction and a second direction intersecting with the first direction. And a first control line connected to the plurality of first pixels and to which a signal for controlling the plurality of first pixels is output, the plurality of light-shielding pixel regions having: a plurality of second pixels arranged in the first direction and the second direction and including a second photoelectric conversion unit that is light-shielded and a second circuit unit that is connected to the second photoelectric conversion unit, and a plurality of first control lines that are connected to the plurality of first pixels and to which a signal for controlling the plurality of first pixels is output, the plurality of light-shielding pixel regions having: a plurality of second pixels that are arranged in the first direction and the second direction; and a second control line which is connected to the plurality of second pixels and to which a signal for controlling the second pixels is output, the light-shielding pixel region being disposed outside the plurality of imaging regions.

Description

[0001] The invention application is a divisional application of the invention application with an international application date of March 29, 2019, an international application number of PCT / JP2019 / 014391, a national application number of 201980096274.6 entering the Chinese national phase, and an invention name of “Image sensor and image sensor device”. Technical Field

[0002] The present invention relates to an imaging element and an imaging device. Background Art

[0003] Patent Document 1 discloses a charge coupled device having an optical black region where a photodiode is arranged and an optical black region where a photodiode is not arranged. However, the charge coupled device of Patent Document 1 does not take into account a plurality of pixel regions for which different control conditions are set.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2006-303856 Summary of the invention

[0007] The imaging element includes an imaging area and a plurality of light-shielded pixel areas, wherein the imaging area includes: a plurality of first pixels, which include a first photoelectric conversion unit that receives light from an optical system and converts it into electric charge and a first circuit unit connected to the first photoelectric conversion unit, and are arranged in a first direction and a second direction intersecting the first direction; and a first control line that is connected to the plurality of first pixels and outputs a signal for controlling the plurality of first pixels, and the plurality of light-shielded pixel areas include: a plurality of second pixels, which include a second photoelectric conversion unit that is light-shielded and a second circuit unit connected to the second photoelectric conversion unit, and are arranged in the first direction and the second direction; and a second control line that is connected to the plurality of second pixels and outputs a signal for controlling the second pixels, and the light-shielded pixel area is arranged outside the following closed area, which includes all the first pixels of the imaging area that are connected to the first control line of the imaging area, and is determined in a way that the outer edge becomes the shortest length. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a cross-sectional view of a stacked image pickup element.

[0009] Figure 2 This is a diagram illustrating the pixel arrangement of an imaging chip.

[0010] Figure 3 This is the circuit diagram of the camera chip.

[0011] Figure 4 This is a block diagram showing a configuration example of an imaging element.

[0012] Figure 5 It is an explanatory diagram showing an example of a functional block configuration of an electronic device.

[0013] Figure 6 It is an explanatory diagram showing the relationship 1 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region.

[0014] Figure 7 : is a circuit diagram showing the circuit structure of the imaging pixel region and the optical black pixel region in the row direction.

[0015] Figure 8 : is a circuit diagram showing the circuit structure of the imaging pixel region and the optical black pixel region in the column direction.

[0016] Fig. 9 It is a timing diagram showing the operation of the block.

[0017] Fig.10 It is an explanatory diagram showing the relationship 2 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region.

[0018] Fig.11 It is an explanatory diagram showing the relationship 3 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region.

[0019] Fig.12 FIG. 4 is a block diagram showing another example of an optical black pixel having a PD.

[0020] Fig.13 This 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 in Example 2.

[0021] Fig.14 This is an explanatory diagram showing an example of a correction table according to the second embodiment.

[0022] Fig.15 : is a circuit diagram showing the circuit structure of the imaging pixel region and the optical black pixel region in the column direction.

[0023] Fig.16 This is an explanatory diagram showing the relationship 1 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region in Example 3.

[0024] Fig.17 This 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 in Example 3.

[0025] Fig.18This 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 in Example 4.

[0026] Fig.19 This is an explanatory diagram showing an example of a correction table according to the fourth embodiment.

[0027] Fig. 20 This is a circuit diagram showing the circuit structure of an imaging pixel region and an optical black pixel region in the row direction.

[0028] Fig.21 This is an explanatory diagram showing the relationship 1 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region in Example 5.

[0029] Fig. 22 This is an explanatory diagram showing relationship 2 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region in Example 5.

[0030] Fig.23 This is an explanatory diagram showing the relationship 1 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region in Example 6.

[0031] Fig.24 This is an explanatory diagram showing the relationship 2 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region in Example 6.

[0032] Fig.25 This is an explanatory diagram showing an example of a correction table according to the sixth embodiment.

[0033] Fig.26 This 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.

[0034] Fig. 27 This is an explanatory diagram showing an example of a correction table according to the seventh embodiment.

[0035] The reference numerals are described as follows:

[0036] 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: driving circuit, 912: control unit. DETAILED DESCRIPTION

[0037] <Structural example of imaging element>

[0038] The imaging element installed in the electronic device shown in the embodiments of this specification is a stacked imaging element. The stacked imaging element is capable of setting different imaging conditions (control conditions) for each of a plurality of different imaging areas. First, the structure of the stacked imaging element capable of setting different imaging conditions (control conditions) for each of a plurality of different imaging areas is described. It should be noted that the stacked imaging element is the stacked imaging element described in Japanese Patent Application No. 2012-139026 previously filed by the applicant of the present application. The electronic device is, for example, an imaging device such as a digital camera or a digital video camera.

[0039] Figure 1 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 a pixel signal corresponding to incident light, a signal processing chip 111 that processes the pixel signal, and a memory chip 112 that stores the pixel signal. The imaging chip 113, the signal processing chip 111, and the memory chip 112 are stacked together and electrically connected to each other using conductive bumps 109 such as Cu.

[0040] In addition, if Figure 1 As shown in FIG. 1 , the incident light is mainly incident in the positive direction of the Z axis indicated by the white arrow. In this embodiment, in the imaging chip 113, the side on which the incident light is incident is called the back side. In addition, as shown in the coordinate axis 120, the left direction of the paper plane perpendicular to the Z axis is set as the positive direction of the X axis, and the front direction of the paper plane perpendicular to the Z axis and the X axis is set as the positive direction of the Y axis. In the following several figures, Figure 1 The coordinate axis 120 is used as a reference, and the coordinate axis 120 is displayed in a manner to make the orientation of each figure clear.

[0041] An example of the imaging chip 113 is a back-illuminated MOS (Metal Oxide Semiconductor) image sensor. The PD (photodiode) layer 106 is arranged on the back side of the wiring layer 108. The PD layer 106 has a plurality of PDs 104 arranged in two dimensions and storing charges corresponding to incident light, and transistors 105 provided corresponding to the PDs 104.

[0042] A color filter 102 is provided on the incident side of the incident light in the PD layer 106 via a passivation film 103. The color filter 102 has a plurality of types that transmit different wavelength ranges, and has a specific arrangement corresponding to each PD 104. The arrangement of the color filter 102 will be described later. A group of the color filter 102, the PD 104, and the transistor 105 forms one pixel.

[0043] Micro lenses 101 are provided corresponding to the respective pixels on the incident side of the color filter 102 . The micro lenses 101 collect the incident light toward the corresponding PD 104 .

[0044] The wiring layer 108 has wirings 107 for transmitting pixel signals from the PD layer 106 to the signal processing chip 111. The wirings 107 may be multi-layered, and may be provided with passive elements and active elements.

[0045] A plurality of bumps 109 are arranged on the surface of the wiring layer 108. By aligning the plurality of bumps 109 with the plurality of bumps 109 provided on the opposite surface of the signal processing chip 111 and applying pressure to the imaging chip 113 and the signal processing chip 111, the aligned bumps 109 are bonded and electrically connected.

[0046] Similarly, a plurality of bumps 109 are arranged on the opposing surfaces of the signal processing chip 111 and the memory chip 112. By aligning the bumps 109 and applying pressure to the signal processing chip 111 and the memory chip 112, the aligned bumps 109 are bonded and electrically connected.

[0047] In addition, the connection between the bumps 109 is not limited to the Cu bump connection based on solid phase diffusion, and micro bump connection based on solder melting can also be adopted. In addition, for example, the bump 109 only needs to be set with respect to one block described later. Therefore, the size of the bump 109 can be larger than the pitch of the PD 104. In addition, in the peripheral area outside the pixel area where pixels are arranged, a bump larger than the bump 109 corresponding to the pixel area can also be provided.

[0048] The signal processing chip 111 has TSVs (Through Silicon Vias) 110 that connect circuits provided on the front and back surfaces to each other. The TSVs 110 are preferably provided in the peripheral region. In addition, the TSVs 110 may also be provided in the peripheral region of the imaging chip 113 or the memory chip 112.

[0049] Figure 2 This is a diagram for explaining the pixel arrangement of the imaging chip 113. In particular, it shows the imaging chip 113 as seen from the back side. Figure 2 (a) is a plan view schematically showing the back side of the imaging chip 113, that is, the imaging surface 200. Figure 2 (b) is a plan view obtained by enlarging a part of the area 200a of the imaging surface 200. Figure 2 As shown in (b) of FIG. 2 , a plurality of pixels 201 are two-dimensionally arranged on the imaging plane 200 .

[0050] Each pixel 201 has a color filter (not shown). The color filter is composed of three colors: red (R), green (G), and blue (B). Figure 2In (b), the symbols "R", "G", and "B" represent the types of color filters that the pixel 201 has. Figure 2 As shown in (b) of FIG. 1 , pixels 201 including such color filters are arranged in a so-called Bayer array on the imaging surface 200 of the imaging element 100 .

[0051] The pixel 201 with a red filter performs photoelectric conversion on the light in the red band of the incident light and outputs a light receiving signal (photoelectric conversion signal). Similarly, the pixel 201 with a green filter performs photoelectric conversion on the light in the green band of the incident light and outputs a light receiving signal. In addition, the pixel 201 with a blue filter performs photoelectric conversion on the light in the blue band of the incident light and outputs a light receiving signal.

[0052] The imaging element 100 is configured to be able to control each block 202 composed of a total of four pixels 201 of adjacent 2 pixels×2 pixels individually. For example, when charge accumulation is started at the same time for two different blocks 202, charge reading, i.e., light-receiving signal reading, can be performed 1 / 30 second after charge accumulation starts in one block 202, and charge reading can be performed 1 / 15 second after charge accumulation starts in the other block 202. In other words, the imaging element 100 can set a different exposure time (charge accumulation time, so-called shutter speed) for each block 202 in one imaging (shooting).

[0053] In addition to the above-mentioned exposure time, the imaging element 100 can also make the amplification factor of the imaging signal (so-called ISO sensitivity) different for each block 202. The imaging element 100 can change the timing of starting charge accumulation and / or the timing of reading the light-receiving signal for each block 202. In other words, the imaging element 100 can change the frame rate when capturing a moving picture for each block 202.

[0054] In summary, the imaging element 100 is configured to make imaging conditions (control conditions) such as exposure time, amplification factor, and frame rate different 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 the imaging signals can be read out independently for each block 202, the exposure time (shutter speed) can be made different for each block 202.

[0055] In addition, if an amplifier circuit (not shown) is independently provided for each block 202 to amplify the imaging signal generated by the charge obtained by photoelectric conversion, and the amplification factor based on the amplifier circuit can be independently controlled for each amplifier circuit, the amplification factor (ISO sensitivity) of the signal can be made different for each block 202.

[0056] In addition, in addition to the above-mentioned imaging conditions (control conditions), different imaging conditions (control conditions) can be set for each block 202, such as frame rate, gain, resolution (thinning rate), the number of rows or columns to add pixel signals, the storage time or number of charges, the number of digitized bits, etc. Furthermore, the control parameters may also be parameters in image processing after acquiring image signals from pixels.

[0057] In addition, regarding the imaging conditions (control conditions), for example, if a liquid crystal panel having partitions (one partition corresponds to one block 202) that can be independently controlled for each block 202 is provided for the imaging element 100, and a neutral density filter that can be turned on and off is used, the brightness (aperture value) can be controlled for each block 202.

[0058] Furthermore, the number of pixels 201 constituting the block 202 may not be the above-mentioned 2×2 four pixels. The block 202 only needs to have at least two pixels 201 , and may have more than four pixels 201 .

[0059] Figure 3 1 is a circuit diagram of the camera chip 113. Figure 3 In FIG. 1 , a rectangle enclosed by a dotted line represents a circuit corresponding to one pixel 201. In addition, a rectangle enclosed by a dashed line corresponds to one block 202 (202-1 to 202-4). In addition, at least a part of each transistor described below corresponds to Figure 1 corresponds to transistor 105.

[0060] As described above, the reset transistor 303 of the pixel 201 is turned on / off in units of the block 202. In addition, the transfer transistor 302 of the pixel 201 is also turned on / off in units of the block 202. Figure 3 In the example shown, a reset wiring 300-1 for turning on / off four reset transistors 303 corresponding to the upper left block 202-1 is provided, and a TX wiring 307-1 for supplying a transfer pulse to four transfer transistors 302 corresponding to the block 202-1 is provided.

[0061] 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 a transmission pulse to the four transmission transistors 302 corresponding to the block 202-3 is provided separately from the TX wiring 307-1.

[0062] Similarly, the upper right block 202 - 2 and the lower right block 202 - 4 are provided with a reset wiring 300 - 2 and a TX wiring 307 - 2 , and a reset wiring 300 - 4 and a TX wiring 307 - 4 , respectively, for each block 202 .

[0063] The 16 PDs 104 corresponding to each pixel 201 are connected to the corresponding transfer transistors 302. A transfer pulse is supplied to the gate of each transfer transistor 302 via the TX wiring of each block 202. The drain of each transfer transistor 302 is connected to the source of the corresponding reset transistor 303, and the 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.

[0064] 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 gates of the reset transistors 303 via the reset wiring of each block 202 .

[0065] The drain of each amplifier transistor 304 is commonly connected to a Vdd wiring 310 to which a power supply voltage is supplied. In addition, 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 decoding wiring 308 to which a selection pulse is supplied. The decoding wiring 308 is independently provided for each of the 16 selection transistors 305.

[0066] Furthermore, the source of each selection transistor 305 is connected to a common output wiring 309. The load current source 311 supplies current to the output wiring 309. That is, the output wiring 309 for the selection transistor 305 is formed by a source follower. In addition, the load current source 311 can be provided on the imaging chip 113 side or on the signal processing chip 111 side.

[0067] Here, the flow from the start of charge storage to pixel output after the storage is completed is described. If a reset pulse is applied to the reset transistor 303 through the reset wiring of each block 202, and a transfer pulse is applied to the transfer transistor 302 through the TX wiring of each block 202 (202-1 to 202-4), the potential of the PD 104 and the floating diffusion FD in each block 202 is reset.

[0068] When the transfer pulse is released, each PD 104 converts the received incident light into electric charge and stores it. Then, when the transfer pulse is applied again without applying the reset pulse, the stored electric charge is transferred to the floating diffusion FD, and the electric potential of the floating diffusion FD changes from the reset potential to the signal potential after the electric charge storage.

[0069] When a selection pulse is applied to the selection transistor 305 via the decoder wiring 308, the change in the signal potential of the floating diffusion FD is transmitted to the output wiring 309 via the amplifier transistor 304 and the selection transistor 305. Thus, a pixel signal corresponding to the reset potential and the signal potential is output from the unit pixel to the output wiring 309.

[0070] As described above, the reset wiring and the TX wiring are common to the four pixels forming the block 202. That is, the reset pulse and the transmission pulse are applied simultaneously to the four pixels in the block 202. Therefore, all the pixels 201 forming a certain block 202 start charge accumulation at the same timing and end charge accumulation at the same timing. However, the pixel signal corresponding to the accumulated charge is selectively output from the output wiring 309 by sequentially applying the selection pulse to each selection transistor 305.

[0071] In this way, the charge storage start timing can be controlled for each block 202. In other words, different blocks 202 can perform imaging at different timings.

[0072] Figure 4 1 is a block diagram showing a configuration example of the imaging element 100. The analog multiplexer 411 sequentially selects 16 PDs 104 forming the block 202 and outputs respective pixel signals to the output wiring 309 provided corresponding to the block 202. The multiplexer 411 is formed in the imaging chip 113 together with the PDs 104.

[0073] The pixel signal outputted via the multiplexer 411 is subjected to CDS and A / D conversion by a signal processing circuit 412 formed in the signal processing chip 111 and performing CDS and A / D conversion. The pixel signal after A / D conversion is delivered to the demultiplexer 413 and stored in the pixel memory 414 corresponding to each pixel. The demultiplexer 413 and the pixel memory 414 are formed in the memory chip 112.

[0074] The operation circuit 415 processes the pixel signal stored in the pixel memory 414 and transmits it to the subsequent image processing unit. The operation circuit 415 can be provided in the signal processing chip 111 or the memory chip 112. Figure 4 Although the connections of the four blocks 202 are shown in FIG. 1 , these connections actually exist in each of the four blocks 202 and operate in parallel.

[0075] However, the operation circuit 415 may not exist for each of the four blocks 202 . For example, one operation circuit 415 may perform processing in sequence while sequentially referring to the values ​​of the pixel memories 414 corresponding to the four blocks 202 .

[0076] As described above, output wirings 309 are provided corresponding to the blocks 202. Since the imaging element 100 stacks the imaging chip 113, the signal processing chip 111, and the memory chip 112, the output wirings 309 can be routed without increasing the size of each chip in the planar direction by using the bumps 109 to electrically connect the chips between the output wirings 309.

[0077] <Example of functional block structure of electronic equipment>

[0078] Figure 5 5 is an explanatory diagram showing an example of a functional block structure of an electronic device. The electronic device 500 is, for example, a camera with an integrated lens. The electronic device 500 includes an imaging optical system 501, an imaging element 100, a control unit 502, a liquid crystal display 503, a memory card 504, an operation unit 505, a DRAM 506, a flash memory 507, and a recording unit 508. The control unit 502 includes a detection unit for detecting hand shaking and subject shaking as described later.

[0079] The imaging optical system 501 is composed of a plurality of lenses, and forms an image of a subject on the imaging plane 200 of the imaging element 100. Figure 5 In FIG. 5 , for the convenience of illustration, the imaging optical system 501 is illustrated as a single lens.

[0080] The imaging element 100 is an imaging element such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device), and captures the subject image formed by the imaging optical system 501 and outputs an imaging signal. The control unit 502 is an electronic circuit that controls various parts 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.

[0081] A predetermined control program is pre-written in the flash memory 507 as a non-volatile storage medium. The processor of the control unit 502 controls each part by reading the control program from the flash memory 507 and executing it. The control program uses the DRAM 506 as a volatile storage medium as a work area.

[0082] The liquid crystal display 503 is a display device using a liquid crystal panel. The control unit 502 causes the imaging element 100 to repeatedly capture an image of a subject at a predetermined period (e.g., 1 / 60 second). Then, various image processing is performed on the imaging signal output from the imaging element 100 to generate a so-called real-time preview image, which is then displayed on the liquid crystal display 503. In addition to the real-time preview image, the liquid crystal display 503 also displays a setting screen for setting imaging conditions (control conditions), etc.

[0083] The control unit 502 generates an image file described below based on the imaging signal output from the imaging element 100, and records the image file in a memory card 504 as a removable recording medium. The operation unit 505 has various operation members such as buttons, and outputs an operation signal to the control unit 502 in accordance with the operation of these operation members.

[0084] The recording unit 508 is composed of, for example, a microphone, and converts the ambient sound into a sound signal and inputs it to the control unit 502. In addition, the control unit 502 may record the dynamic image file not on the memory card 504 as a removable recording medium, but on a recording medium (not shown) such as an SSD (Solid State Drive) or a hard disk built into the electronic device 500.

[0085] In the above Figure 1 to Figure 5 In the embodiment shown below, the common parts in each embodiment are described. Next, the imaging element and the imaging device of each embodiment are described.

[0086] [Example 1]

[0087] Embodiment 1 has the following structure: the number of non-imaging areas in the optical black pixel area is greater than the number of imaging areas in the imaging pixel area (greater than or equal to the number of imaging areas in the imaging pixel area), and the non-imaging areas are arranged at positions different from the imaging pixel areas.

[0088] <Relationship between control conditions of imaging pixel area and control conditions of optical black pixel area>

[0089] Next, use Figure 6 , Fig.10 , Fig.11 The control conditions of the imaging pixel region, the control conditions of the optical black pixel region, and the arrangement of the imaging pixel region and the optical black pixel region in Example 1 are described. Fig.10 and Fig.11 In, pay attention to Figure 6 The differences between Figure 6 Description of the same parts will be omitted.

[0090] Figure 6 1 is an explanatory diagram showing the relationship 1 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region in Example 1. Figure 6 In , the x direction is set as the row direction and the y direction is set as the column direction. Figure 2The imaging plane 200 shown has an imaging pixel region 600 and an optical black pixel region 610. Here, the imaging pixel region 600 is a region where imaging pixels 6, such as a plurality of PDs 104 storing charges corresponding to incident light, are arranged in two dimensions. The optical black pixels have the same structure as the pixels arranged in the imaging pixel region, but are pixels in which the PDs 104 are shielded from light. The optical black pixel region 610 is, for example, a region where optical black pixels are arranged in one dimension or two dimensions.

[0091] The imaging area is, for example, a collection of one or more blocks 202. Figure 6 In order to simplify the description, the imaging pixel area 600 is composed of 2 rows and 2 columns of imaging areas 600-11, 600-12, 600-21, and 600-22. However, the imaging pixel area 600 can also be composed of m rows and n columns (m and n are integers greater than 1. There are more than two imaging areas 600) other than 2 rows and 2 columns. When the imaging areas 600-11, 600-12, 600-21, and 600-22 are not distinguished, they are expressed as imaging areas 600-ij. Each imaging area 600-ij can be controlled under control conditions different from those of other imaging areas 600-ij.

[0092] The optical black pixel area 610 is composed of a plurality of non-imaging areas 610-L1 to 610-L4, 610-C1 to 610-C4 where no subject is photographed. Each of the non-imaging areas 610-L1 to 610-L4, 610-C1 to 610-C4 includes at least one of the optical black pixel group without PD and the optical black pixel group with PD, for example.

[0093] The optical black pixel groups without PD or with PD in each non-imaging area 610-L1 to 610-L4 and 610-C1 to 610-C4 are, for example, the same as those using Figure 3 The block 202 described above is similarly provided with a structure in which each pixel is arranged in a two-dimensional shape. The optical black pixel group without PD or the optical black pixel group with PD has a structure capable of being controlled with different control conditions for each non-imaging area 610-L1 to 610-L4, 610-C1 to 610-C4.

[0094] Here, in each embodiment, the non-imaging area having a PD-free optical black pixel group is also referred to as a light-shielding pixel area. A plurality of non-imaging areas 610-L1 to 610-L4 are non-imaging area groups existing in the column direction. In the case where the non-imaging area group existing in the column direction is not distinguished, it is expressed as a non-imaging area 610-Lp. A plurality of non-imaging areas 610-C1 to 610-C4 are non-imaging area groups existing in the row direction.

[0095] When the non-imaging area group existing in the row direction is not distinguished, it is expressed as a non-imaging area 610-Cq. When the multiple non-imaging areas 610-L1 to 610-L4 and 610-C1 to 610-C4 are not distinguished, they are expressed as non-imaging areas 610-pq. One non-imaging area 610-pq includes a PD optical black pixel group and a PD-free optical black pixel group.

[0096] The optical black pixel region 610 is located outside the imaging pixel region 600 and adjacent to it. Figure 6 As an example, the optical black pixel region 610 is disposed at the right end and the lower end of the imaging pixel region 600. The optical black pixel region 610 may be disposed at at least one of the upper end, the lower end, the right end, and the left end of the imaging pixel region 600.

[0097] The optical black pixel region 610 includes an optical black pixel group with PD and an optical black pixel group without PD. The optical black pixel group with PD is a collection of optical black pixels with PD. The optical black pixel with PD is a black pixel having PD 104. Specifically, for example, the optical black pixel with PD is a pixel having a light shielding layer that shields the incident light of the subject.

[0098] The PD-free optical black pixel group is a collection of PD-free optical black pixels. The PD-free optical black pixels are black pixels that do not have PD 104. Black level correction is performed by subtracting the output from the PD-free optical black pixel or the output signal from the PD-free optical black pixel from the output signal from the imaging pixel to remove noise such as dark current components.

[0099] In addition, the number of non-image capture areas 610-pq is greater than the number of image capture areas 600-ij. Figure 6 In the figure, the number of non-imaging areas 610 - pq is eight, and the number of imaging areas 600 - ij is four.

[0100] In addition, the non-imaging area 610-Cq is arranged in 2 rows and 2 columns. The non-imaging areas 610-C1 and 610-C3 are arranged in the column direction, and the PD-free optical black pixel group of the non-imaging area 610-C1 is adjacent to the PD-free optical black pixel group of the non-imaging area 610-C3. Similarly, the non-imaging areas 610-C2 and 610-C4 are arranged in the column direction, and the PD-free optical black pixel group of the non-imaging area 610-C2 is adjacent to the PD-free optical black pixel group of the non-imaging area 610-C4. In this way, the PD-free optical black pixel group of the non-imaging area 610-Cq is not separated, so the number of arrangements of the PD-free optical black pixel group can be reduced, thereby reducing the manufacturing cost.

[0101] <Circuit Structure of Imaging Pixel Region 600 and Optical Black Pixel Region 610>

[0102] Figure 7 1 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 the first embodiment. Figure 8 1 is a circuit diagram showing the circuit structure of the imaging pixel region 600 and the optical black pixel region 610 in the column direction of Example 1. Figure 7 and Figure 8 In the example, the pixel 201 in the imaging pixel region 600 is set as the imaging pixel 201 - 1 , and the pixel 201 in the optical black pixel region 610 is set as the optical black pixel with PD 201 - 2 and the optical black pixel without PD 201 - 3 .

[0103] The pixel 201 has a transfer transistor 302, a reset transistor 303, an amplifying transistor 304, a selection transistor 305, and a floating diffusion FD. The imaging pixel 201-1 also has a red (R), G (green), or blue (B) color filter 102 and a PD 104. The optical black pixel 201-2 with PD also has a light shielding layer 700 and a PD 104. The optical black pixel 201-3 without PD has neither a filter nor a PD 104.

[0104] The imaging pixel 201-1 generates charges according to the amount of light incident through the color filter 102. On the other hand, the optical black pixel 201-2 with PD does not generate charges according to the amount of incident light because it has the light shielding layer 700, but generates charges corresponding to thermal noise.

[0105] The transfer transistors 302 of the imaging pixel 201-1 and the optical black pixel with PD 201-2 transfer the charge stored in the PD 104 to the floating diffusion FD when the control signals TX_C and TX_O1 from the drive circuit 711 are provided to the gate thereof. The transfer transistor 302 of the optical black pixel without PD 201-3 does not generate charge from the PD 104 even when the control signal TX_O2 from the drive circuit 711 is provided to the gate thereof.

[0106] The reset transistor 303 sets the potential of the floating diffusion FD to a potential substantially equal to Vdd when the control signal RST from the drive circuit 711 is supplied to the gate thereof. For example, the reset transistor 303 discharges electrons stored in the floating diffusion FD.

[0107] When the control signals SEL_C, SEL_O1 , and SEL_O2 from the drive circuit 711 are supplied to the gate of the selection transistor 305 , the selection transistor 305 outputs a current to the column readout lines 701 to 703 at the voltage amplified by the amplifier transistor 304 . Figure 8 The column readout lines 701-1 to 701-4 are connected to Figure 7The column readout line 701 is equivalent to.

[0108] 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 level equivalent to thermal noise is output from the column readout line 702. A signal corresponding to a black level serving as a reference 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 and an AD conversion circuit (not shown).

[0109] The signal processing unit 710 inputs a signal corresponding to the amount of charge obtained by photoelectric conversion in the imaging pixel 201-1. The signal processing unit 710 inputs a signal corresponding to thermal noise detected in the optical black pixel with PD 201-2. The signal processing unit 710 sets the signal from the optical black pixel without PD 201-3 as a reference for the black level of the imaging pixel 201-1.

[0110] 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. Thus, noise such as dark current is removed. In addition, the signal processing unit 710 can be implemented by a circuit or by executing a program stored in a memory by a processor.

[0111] Driving circuit 711 (in Figure 8 (not shown in the figure) control signals TX, RST, SEL which are signal pulses are supplied to the gates of the transmission transistor 302, the reset transistor 303, and the selection transistor 305. As a result, the transmission transistor 302, the reset transistor 303, and the selection transistor 305 are turned on.

[0112] Control unit 712 (in Figure 8 The control unit 712 controls the drive circuit 711 by controlling the pulse timing to each gate of the transfer transistor 302, the reset transistor 303 and the selection transistor 305. In addition, the control unit 712 controls the operation of the signal processing unit 710.

[0113] <Time chart showing the operation of block 202>

[0114] Fig. 9 1 is a timing chart showing the operation of the block 202 of Example 1. The drive circuit 711 controls the transfer transistor 302 and the reset transistor 303 at the same timing in one block 202. However, for the pixels 201 provided with the color filter 102 having the same spectral characteristics, the drive circuit 711 outputs the pixel signal from the selection transistor 305 at a staggered timing for each pixel 201.

[0115] For example, at time t2, the driver circuit 711 turns on each reset transistor 303 (RST) of one block 202. As a result, the potential of the gate of each amplifier transistor 304 is reset. The driver circuit 711 keeps each reset transistor 303 (RST) turned on during the period from time t2 to time t5.

[0116] At time t3, the driving circuit 711 turns on all the transfer transistors 302 in one block 202. Thereby, first, the charge accumulated in the PD 104 existing in the block 202 is reset.

[0117] The driver circuit 711 turns off each reset transistor 303 (RST) at time t5. Then, the driver circuit 711 turns on all the transfer transistors 302 in one block 202 again at time t7. Thus, the charges accumulated in the PD 104 in one block 202 are transferred to the corresponding floating diffusions FD.

[0118] During the period from time t3 to time t7, the pixel 201 having the PD 104 in one block 202 accumulates electric charge. That is, the period from time t3 to time t7 is a period during which the pixel 201 having the PD 104 accumulates electric charge.

[0119] 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 the column readout lines 701 to 703, for example.

[0120] At time t9, the charges accumulated in other PDs 104 in other blocks 202 are transferred to the column readout lines 701 to 703. This transfer operation is performed for each pixel 201 in one block 202. Thus, pixel signals of each pixel 201 included in one block 202 are output to the column readout lines 701 to 703.

[0121] return Figure 6 , illustrating the positional relationship between the imaging area 600-ij and the non-imaging area 610-pq. As described above, each imaging area 600-ij has a structure in which the imaging pixels 6 are arranged in a two-dimensional shape. The imaging pixels 6 of each imaging area 600-ij, for example, have the same Figure 2 The same structure as the block 202 described above can be controlled with different control conditions for each imaging area 600-ij.

[0122] Here, a closed area 60 is considered, which includes all the imaging pixels 6 of the imaging area 600-ij connected to the control lines (TX wiring 307, etc.) of each imaging area 600-ij and is determined in such a way that the outer edge has the shortest length. The non-imaging area 610-pq is located outside the closed area 60. By having such a structure, the imaging pixels 6 can be arranged in the same manner inside each imaging area 600-ij. Therefore, it is possible to ensure high quality for the image generated by the imaging pixels 6 of each imaging area 600-ij without generating so-called defective pixels.

[0123] Next, the control conditions and black level correction set for the imaging pixel area 600 and the optical black pixel area 610 are described. Control conditions are set for each imaging area 600-ij. For example, control condition A is set for the imaging areas 600-11 and 600-21, and control condition B is set for the imaging areas 600-12 and 600-22. Similarly, control condition A is set for the non-imaging areas 610-L1, 610-L3, 610-C1, and 610-C3, and control condition B is set for the non-imaging areas 610-C2, 610-L4, 610-C2, and 610-C4.

[0124] 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 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.

[0125] The dotted line with black circles at both ends indicates that the imaging area 600-ij and the non-imaging area 610-pq where the black circle is located correspond to each other in the row direction in the black level correction. The imaging area 600-ij where the black circle is located is called the "reference source imaging area 600-ij" for black level correction, and the non-imaging area 610-pq where the black circle is located is called the "reference target non-imaging area 610-pq" for black level correction (the same is true for the single-point dashed line with black circles at both ends described later).

[0126] The pixel groups arranged in the row direction are selected at the same timing in units of the row selection circuit or block 202, and pixel signals are output. Therefore, the reference source imaging area 600-ij and the reference target non-imaging area 610-pq are considered to have a correlation related to dark current, etc. Therefore, in the case of performing black level correction on the output signal from the reference source imaging area 600-ij, by subtracting the output signal from the reference source imaging area 600-ij using the output signal of the reference target non-imaging area 610-pq, high-precision black level correction corresponding to the reference source imaging area 600-ij can be achieved.

[0127] In addition, a single-dot chain line with black circles at both ends indicates that the imaging area 600-ij and the non-imaging area 610-pq where the black circles are located correspond to each other in the column direction in black level correction. The pixel groups arranged in the column direction are connected to a common column readout line and output analog signals respectively, which are converted into digital signals by a common A / D converter.

[0128] Therefore, the reference source imaging region 600-ij and the reference target non-imaging region 610-pq are considered to have a correlation related to dark current, etc. Therefore, when the black level correction is performed 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 target non-imaging region 610-pq, a high-precision black level correction corresponding to the reference source imaging region 600-ij can be achieved.

[0129] As described above, the number of non-camera regions 610-pq is greater than the number of camera regions 600-ij. Therefore, one camera region 600-ij can correspond to more than one non-camera region 610-pq in black level correction. In addition, in black level correction, for the camera region 600-ij, it can be preset which direction of the output signal of the non-camera region 610-pq in the row direction and the column direction is used, and it can also be set according to the control conditions of each camera region 600-ij and each non-camera region 610-pq. Alternatively, for the camera region 600-ij, the larger, smaller or average value of the output signals of the non-camera region 610-pq in both the row direction and the column direction can be used.

[0130] In addition, in the above example, the "reference source imaging area 600-ij" and the "reference target non-imaging area 610-pq" are selected at the same timing in units of the row selection circuit or block 202, or are converted into digital signals using a common A / D converter, but the present invention is not limited thereto. For example, the "reference source imaging area 600-ij" and the "reference target non-imaging area 610-pq" may not be selected at the same timing in units of the row selection circuit or block 202, and may not be converted into digital signals using a common A / D converter.

[0131] Even with such a structure, by controlling the "reference source imaging area 600-ij" and the "reference target non-imaging area 610-pq" under the same control conditions, a correlation related to dark current, etc. is generated in the "reference source imaging area 600-ij" and the "reference target non-imaging area 610-pq". Therefore, by using the output signal from the reference target non-imaging area 610-pq to subtract the output signal from the reference source imaging area 600-ij, high-precision black level correction corresponding to the reference source imaging area 600-ij can be achieved.

[0132] Fig.10 This 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 in Example 1. Fig.10 also with Figure 6 Similarly, this is an example in which the number of non-image capture areas 610 is greater than the number of image capture areas 600. Fig.10 In, replace Figure 6 The non-imaging regions 610 - C2 , 610 - L4 , 610 - C2 , and 610 - C4 shown in the figure show a structure in which the non-imaging regions 610 - C5 , 610 - L6 , 610 - C7 , and 610 - C8 are arranged in the row direction.

[0133] The control condition A is set for the non-imaging areas 610-C5 and 610-L6, and the control condition B is set for the non-imaging areas 610-C7 and 610-L8. Figure 6 Similarly, it is shown as a dotted line with black circles at both ends and a dashed line with black circles at both ends. Since the non-camera areas 610-C5, 610-L6, 610-C7, and 610-C8 are arranged in only one row in the row direction, Figure 6 In comparison, the area of ​​the imaging pixel region 600 can be increased.

[0134] Fig.11 This is an explanatory diagram showing relationship 3 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region in Example 1. Fig.11 also with Figure 6 Similarly, this is an example in which the number of non-image capture areas 610 is greater than the number of image capture areas 600. Fig.11 In the example, control condition A is set for the imaging region 600-11, control condition B is set for the imaging region 600-12, control condition C is set for the imaging region 600-21, and control condition D is set for the imaging region 600-22.

[0135] In addition, Fig.11 In, replace Figure 6The non-camera regions 610-C2, 610-L4, 610-C2, 610-C4 are shown as non-camera regions 610-C5, 610-L6, 610-C7, 610-C8 arranged in the row direction. Control condition A is set for the non-camera region 610-C5, control condition C is set for the non-camera region 610-L6, control condition B is set for the non-camera region 610-C5, and control condition D is set for the non-camera region 610-C8.

[0136] In addition, control condition A is set for the non-camera area 610-L1, control condition B is set for the non-camera area 610-L2, control condition C is set for the non-camera area 610-L3, and control condition D is set for the non-camera area 610-L4.

[0137] The control conditions A to D are different from each other. Figure 6 Similarly, it is as shown by a dotted line with black circles at both ends and a dashed line with black circles at both ends.

[0138] Since the non-camera areas 610-C5, 610-L6, 610-C7, and 610-C8 are arranged in only one row in the row direction, Figure 6 In comparison, the area of ​​the imaging pixel region 600 can be increased. In addition, the number of different control conditions can be set to a maximum of the number of imaging regions. Figure 6 , Fig.10 , Fig.11 In the embodiment, the number of the camera areas 600 is four, but in Figure 6 and Fig.10 In the experiment, the number of different control conditions is two, A and B.

[0139] In contrast, Fig.11 In the example, four control conditions A to D are set as different control conditions. In this way, the number of control conditions can be set in proportion to the number of imaging areas 600. Therefore, various control conditions can be combined, and the degree of freedom of imaging can be improved.

[0140] <Other examples of PD optical black pixel 201-2>

[0141] Fig.12 1 is a block diagram showing another example of the PD optical black pixel 201-2 of the first embodiment. In the PD optical black pixel 201-4, the output of the PD 104 is connected to the input of the PD 104. In addition, the PD 104 and the transmission transistor 302 are short-circuited to the ground line. Figure 7 and Figure 8 The structures shown are the same.

[0142] Therefore, charges resulting from photoelectric conversion are hardly stored in the PD 104. Even if charges are stored in the PD 104, the charges are not read out as pixel signals, but charges resulting from dark current or the like are stored in the floating diffusion FD.

[0143] As described above, according to the first embodiment, black level correction can be performed for each imaging region 600-ij of the imaging pixel region 600 using the non-imaging region 610-pq outside the imaging pixel region 600 having correlation. Therefore, high-precision black level correction can be achieved for each imaging region 600-ij.

[0144] In addition, a closed area 60 is considered, which includes all the imaging pixels 6 of the imaging area 600-ij connected to the control lines (TX wiring 307, etc.) of each imaging area 600-ij and is determined in such a way that the outer edge has the shortest length. The non-imaging area 610-pq is located outside the closed area 60. Thus, the imaging pixels 6 can be arranged in the same manner inside each imaging area 600-ij. Therefore, it is possible to ensure high quality for the image generated by the imaging pixels 6 of each imaging area 600-ij without generating so-called defective pixels.

[0145] [Example 2]

[0146] In Example 2, 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 reference numerals are given to the same structures as those in Example 1, and their description is omitted.

[0147] <Relationship between control conditions of imaging pixel area and control conditions of optical black pixel area>

[0148] Fig.13 This is an explanatory diagram showing the relationship between the control conditions of the imaging pixel area 600 and the control conditions of the optical black pixel area in Example 2. The optical black pixel area 610 is composed of a plurality of non-imaging areas 610-L1 to 610-L2 that do not capture the subject. The plurality of non-imaging areas 610-L1 to 610-L2 are a non-imaging area group existing in the column direction. When the non-imaging area group is not distinguished, it is expressed as a non-imaging area 610-Lp.

[0149] The optical black pixel region 610 is located outside the imaging pixel region 600 and adjacent to it. Fig.13 As an example, it is arranged at the right end of the imaging pixel region 600. The configuration position of the optical black pixel region 610 can be at least one of the right end and the left end of the imaging pixel region 600. In addition, the number of non-imaging regions 610-Lp is less than the number of imaging regions 600-ij. Fig.13In the figure, the number of non-imaging areas 610-Lp is two, and the number of imaging areas 600-ij is four.

[0150] Next, the control conditions set for the imaging pixel area 600 and the optical black pixel area 610 are described. Control conditions are set for each imaging area 600-ij. For example, control condition A is set for imaging areas 600-11 and 600-12, and control condition B is set for imaging areas 600-21 and 600-22. Similarly, control condition A is set for the non-imaging area 610-L1, and control condition B is set for the non-imaging area 610-L2.

[0151] and Figure 6 Similarly, the dotted line with black circles at both ends indicates that the imaging area 600-ij and the non-imaging area 610-pq where the black circle is located correspond to each other in the row direction in the black level correction. The imaging area 600-ij where the black circle is located is called the "reference source imaging area 600-ij" for black level correction, and the non-imaging area 610-pq where the black circle is located is called the "reference target non-imaging area 610-pq" for black level correction (the same is true for the single-point dashed line with black circles at both ends described later).

[0152] The pixel groups arranged in the row direction are selected at the same timing in units of the row selection circuit or block 202, and pixel signals are output. Therefore, the reference source imaging region 600-ij and the reference target non-imaging region 610-Lp are considered to have a correlation related to dark current, etc. Therefore, in the case of performing black level correction on the output signal from the reference source imaging region 600-ij, the output signal from the reference target non-imaging region 610-Lp is subtracted from the output signal from the reference source imaging region 600-ij, so that black level correction can be achieved corresponding to the reference source imaging region 600-ij.

[0153] As described above, the number of non-imaging areas 610-Lp is less than the number of imaging areas 600-ij. Therefore, one imaging area 600-ij can correspond to more than one non-imaging area 610-Lp in black level correction. In addition, black level correction is performed for each row, but it can also be performed for each area. That is, the signal levels of the imaging area 600-11 can also be corrected by using the value obtained by averaging the output of the signal of the non-imaging area 610-L1.

[0154] <Calibration table>

[0155] Fig.1414 is an explanatory diagram showing an example of a correction table of Example 2. 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 target non-imaging area 1403, and a reference target control condition 1404. In the reference source imaging area 1401, the reference source imaging area 600-ij is stored as a value. In the reference source control condition 1402, the control condition of the reference source imaging area 600-ij is stored as a value. In the reference target non-imaging area 1403, the non-imaging area 610-Lp that becomes the reference target of the reference source imaging area 600-ij is stored as a value. In the reference target control condition 1404, the control condition of the non-imaging area 610-Lp is stored as a value.

[0156] In the correlation value 1405, a value representing the correlation between the reference source imaging area 1401 in which the reference source control condition 1402 is set and the reference target non-imaging area 1403 in which the reference target control condition 1404 is set is stored as a value (correlation value r(ijX, LpY). X is the reference source control condition 1402, and Y is the reference target control condition 1404).

[0157] In addition, there is also a case where the correlation value r(ijX, LpY) is 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 target non-imaging area 1403 is, and the farther away from 1.0, the lower the correlation between the reference source imaging area 1401 and the reference target non-imaging area 1403 is.

[0158] Here, the output from the optical black pixel with PD or the output from the optical black pixel without PD in the reference target non-imaging area 610 -Lp is denoted as Q, and the corrected noise component is denoted as P. The relationship between P and Q is expressed by the following equation (1).

[0159] P=r×Q+b· · · (1)

[0160] b is an arbitrarily set adjustment value, and is a value determined for each imaging element 100. The calculation using the above equation (1) is performed by, for example, the signal processing unit 810 described later.

[0161] The correlation value tends to be close to 1.0 if the reference source imaging region 1401 and the reference target non-imaging region 1403 are in the same row. Fig.13In the case where the reference source imaging region 1401 is the imaging region 600-11, if the reference target non-imaging region 1403 is the non-imaging region 610-L1, the correlation value becomes closer to 1.0 than when the reference target non-imaging region 140 is the non-imaging region 610-L2. This is because if they are the same row, they are read out by the column readout line at the same timing.

[0162] In addition, the correlation value r tends to be closer to 1.0 as the reference source imaging region 1401 and the reference target non-imaging region 1403 are closer. Fig.13 In the case where the reference source imaging region 1401 is the imaging region 600-12, if the reference target non-imaging region 1403 is the non-imaging region 610-L1, the correlation value r becomes closer to 1.0 than when the reference source imaging region 1401 is the imaging region 600-11. This is because it is believed that the closer the pixel positions are, the more similar their characteristics are.

[0163] In addition, if the reference source control condition 1402 is the same as the reference target control condition 1404, the correlation value r becomes a value close to 1.0. Specifically, for example, when the reference source control condition 1402 and the reference target control condition 1404 are the same type of control conditions but have different values, the correlation value r becomes a value closer to 1.0 than when the reference source control condition 1402 and the reference target control condition 1404 are different types. This is because if the control conditions are the same type, the operation conditions of the reference source imaging area 1401 and the operation conditions of the reference target non-imaging area 1403 are the same.

[0164] Furthermore, the object of correction of the noise component using the correlation value r may be limited to the reference source imaging region 1401 which is not adjacent to the reference target non-imaging region 1403. For example, when the reference target non-imaging region 1403 is the non-imaging region 610-L1, the reference source imaging region 1401 is the imaging region 600-11. In this case, the imaging region 600-12 is adjacent to the imaging region 610-L1 and is therefore not set as the reference source imaging region 1401. Thus, since the calibration target imaging region is limited, the data of the correction table 1400 becomes smaller.

[0165] <Circuit Structure of Imaging Pixel Region 600 and Optical Black Pixel Region 610>

[0166] Fig.15 6 is a circuit diagram showing the circuit structure of the imaging pixel region 600 and the optical black pixel region 610 in the column direction. Fig.11 Same. Fig.11 and Fig.15In the example, the pixel 201 in the imaging pixel region 600 is set as the imaging pixel 201 - 1 , and the pixel 201 in the optical black pixel region 610 is set as the optical black pixel with PD 201 - 2 and the optical black pixel without PD 201 - 3 .

[0167] When the control signals SEL_C, SEL_O1 , and SEL_O2 from the driving circuit 811 are supplied to the gate of the selection transistor 305 , the selection transistor 305 outputs a current to the column readout lines 701 to 703 at the voltage amplified by the amplifier transistor 304 . Fig.15 The column readout lines 1503-1 to 1503-4 are connected to Fig. 9 The column readout line 703 is equivalent.

[0168] As described above, according to the second embodiment, black level correction can be performed for each imaging region 600-ij of the imaging pixel region 600 using the non-imaging region 610-Lp having correlation with the imaging region 600-ij. Therefore, high-precision black level correction can be achieved for each imaging region 600-ij.

[0169] [Example 3]

[0170] Embodiment 3 is described. In Embodiment 2, an imaging element with the same control conditions set for the same row is described, and in Embodiment 3, an imaging element with different control conditions set for the same row is described. The same reference numerals are given to the same structures as in Embodiments 1 and 2, and their description is omitted.

[0171] Fig.16 This is an explanatory diagram showing the relationship 1 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region in Example 3. Fig.17 This 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 in Example 3. Fig.16 and Fig.17 also with Fig.13 Likewise, this is an example in which the number of non-imaging regions 610 is smaller than the number of imaging regions 600 .

[0172] exist Fig.16 In the example, control condition B is set for the imaging area 600-12 and the non-imaging area 610-L1, and control condition A is set for the imaging area 600-22 and the non-imaging area 610-L2.

[0173] and Fig.13 The difference is that in Fig.13 In the example, the control condition of the non-camera region 610-L1 as the reference target non-camera region 1403 of the camera region 600-11 is A. Fig.16In the example, the control condition of the non-image area 610-L1 is not A but B. Fig.13 In the example, the control condition of the non-camera region 610-L2 as the reference target non-camera region 1403 of the camera region 600-21 is A. Fig.16 In the figure, the control condition of the non-imaging area 610-L2 is not B but A.

[0174] In addition, Fig.17 In the example, control condition B is set for the imaging area 600-12 and the non-imaging area 610-L1, control condition C is set for the imaging area 600-21, and control condition D is set for the imaging area 600-22 and the non-imaging area 610-L2.

[0175] and Fig.13 The difference is that in Fig.13 In the example, the control condition of the non-camera region 610-L1 as the reference target non-camera region 1403 of the camera region 600-11 is A. Fig.17 In the example, the control condition of the non-image area 610-L1 is not A but B. Fig.13 In the example, the control condition of the non-camera region 610-L2 as the reference target non-camera region 1403 of the camera region 600-21 is A. Fig.17 In the example, the control condition of the non-imaging area 610-L2 is not A but D.

[0176] In such a case as well, by appropriately setting the correlation value r, the signal processing unit 810 can calculate the black level correction with high accuracy using the above-mentioned equation (1).

[0177] As described above, according to the third embodiment, black level correction can be performed for each imaging region 600-ij of the imaging pixel region 600 using the non-imaging region 610-Lq outside the imaging pixel region 600 having correlation. Therefore, high-precision black level correction can be achieved for each imaging region 600-ij.

[0178] [Example 4]

[0179] Embodiment 4 is described. Embodiment 2 shows an imaging element in which the same control condition is set for the same row, and Embodiment 4 shows an imaging element in which the same control condition is set for the same column. The same reference numerals are given to the same configurations as Embodiments 1 to 3, and their description is omitted.

[0180] <Relationship between control conditions of imaging pixel area and control conditions of optical black pixel area>

[0181] Fig.18This is an explanatory diagram showing the relationship between the control conditions of the imaging pixel area and the control conditions of the optical black pixel area in Example 4. The optical black pixel area 610 is composed of a plurality of non-imaging areas 610-C1 to 610-C2 that do not capture the subject. The plurality of non-imaging areas 610-C1 to 610-C2 are a non-imaging area group existing in the column direction. When the non-imaging area group is not distinguished, it is expressed as a non-imaging area 610-Cq.

[0182] The optical black pixel region 610 is located outside the imaging pixel region 600 and adjacent to it. Fig.18 In the example, the optical black pixel region 610 is provided at the lower end side of the imaging pixel region 600. The optical black pixel region 610 may be provided at least at one of the upper end side and the lower end side of the imaging pixel region 600.

[0183] In addition, the number of non-imaging areas 610-Cq is less than the number of imaging areas 600-ij. Fig.18 In the figure, the number of non-imaging areas 610-Cq is two, and the number of imaging areas 600-ij is four.

[0184] Next, the control conditions set for the imaging pixel area 600 and the optical black pixel area 610 are described. Control conditions are set for each imaging area 600-ij. For example, control condition A is set for imaging areas 600-11 and 600-21, and control condition B is set for imaging areas 600-12 and 600-22. Similarly, control condition A is set for the non-imaging area 610-C1, and control condition B is set for the non-imaging area 610-C2.

[0185] The dotted line with black circles at both ends indicates that the imaging area 600-ij and the non-imaging area 610-pq where the black circle is located correspond to each other in the row direction in the black level correction. The imaging area 600-ij where the black circle is located is called the "reference source imaging area 600-ij" for black level correction, and the non-imaging area 610-pq where the black circle is located is called the "reference target non-imaging area 610-pq" for black level correction (the same is true for the single-point dashed line with black circles at both ends described later).

[0186] The pixel groups arranged in the column direction are connected to the common column readout lines and output analog signals respectively, which are converted into digital signals by a common A / D converter. Therefore, the reference source imaging area 600-ij and the reference target non-imaging area 610-Cq are considered to have a correlation (high) related to dark current, etc. Therefore, in the case of performing black level correction on the output signal from the reference source imaging area 600-ij, by subtracting the output signal from the reference source imaging area 600-ij from the output signal of the reference target non-imaging area 610-Cq, high-precision black level correction corresponding to the reference source imaging area 600-ij can be achieved.

[0187] 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 black level correction.

[0188] <Calibration table>

[0189] Fig.19 1400 is an explanatory diagram showing an example of a correction table of Example 4. The correction table 1900 is a table in which a correlation value 1405 is set for each combination of a reference source imaging region 1401, a reference source control condition 1402, a reference target non-imaging region 1403, and a reference target control condition 1404. In the reference target non-imaging region 1403, a non-imaging region 610-Cq serving as a reference target of the reference source imaging region 600-ij is stored as a value. In the reference target control condition 1404, a control condition of the non-imaging region 610-Cq is stored as a value.

[0190] In the correlation value 1405, a value representing the correlation between the reference source imaging area 1401 in which the reference source control condition 1402 is set and the reference target non-imaging area 1403 in which the reference target control condition 1404 is set is stored as a value (correlation value r(ijX, CqY). X is the reference source control condition 1402, and Y is the reference target control condition 1404).

[0191] In addition, there is also a case where the correlation value r(ijX, CqY) is 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 target non-imaging area 1403 is, and the farther away from 1.0, the lower the correlation between the reference source imaging area 1401 and the reference target non-imaging area 1403 is.

[0192] Here, the output from the optical black pixel with PD or the output from the optical black pixel without PD in the reference target non-imaging area 610 -Cq is denoted as Q, and the corrected noise component is denoted as P. The relationship between P and Q is expressed by the above equation (1).

[0193] If the reference source imaging region 1401 and the reference target non-imaging region 140 are in the same column, the correlation value r becomes close to 1.0. Fig.18 In the case where the reference source imaging region 1401 is the imaging region 600-11, if the reference target non-imaging region 1403 is the non-imaging region 610-C1, the correlation value r becomes closer to 1.0 than when the reference target non-imaging region 1403 is the non-imaging region 610-C2. This is because if they are in the same column, they are read out with the same column readout line.

[0194] In addition, the closer the reference source imaging area 1401 is to the reference target non-imaging area 1403, the closer the correlation value r is to 1.0. Fig.18 In the case where the reference source imaging region 1401 is the imaging region 600-21, if the reference target non-imaging region 1403 is the non-imaging region 610-C1, the correlation value r becomes closer to 1.0 than when the reference source imaging region 1401 is the imaging region 600-11. This is because it is believed that the closer the pixel positions are, the more similar their characteristics are.

[0195] Furthermore, the correction target of the noise component using the correlation value r may be limited to the reference source imaging region 1401 that is not adjacent to the reference target non-imaging region 1403. For example, when the reference target non-imaging region 1403 is the non-imaging region 610-C1, the reference source imaging region 1401 is the imaging region 600-11.

[0196] In this case, since the imaging region 600-21 is adjacent to the imaging region 610-C1, it is not set as the reference source imaging region 1401. Thus, since the calibration target imaging region is limited, the data of the correction table 1900 becomes smaller.

[0197] <Circuit Structure of Imaging Pixel Region 600 and Optical Black Pixel Region 610>

[0198] Fig. 20 6 is a circuit diagram showing the circuit structure of the imaging pixel region 600 and the optical black pixel region 610 in the row direction. The circuit structure of the imaging pixel region 600 and the optical black pixel region 610 in the column direction is similar to that of Fig.10 same.

[0199] When the control signals SEL_C, SEL_O1 , and SEL_O2 from the driving circuit 811 are supplied to the gate of the selection transistor 305 , the selection transistor 305 outputs a current to the column readout lines 701 to 703 at the voltage amplified by the amplifier transistor 304 . Fig.10 The column readout lines 701-1 to 701-4 are connected to Fig. 20 The column readout lines 702 and 703 are equivalent.

[0200] As described above, according to the fourth embodiment, black level correction can be performed for each imaging region 600-ij of the imaging pixel region 600 using the non-imaging region 610-Cq outside the imaging pixel region 600 having correlation. Therefore, high-precision black level correction can be achieved for each imaging region 600-ij.

[0201] [Example 5]

[0202] Embodiment 5 will be described. Embodiment 4 shows an imaging element with the same control conditions set for the same column, and Embodiment 5 shows an imaging element with different control conditions set for the same column. The same reference numerals are used for the same configurations as Embodiments 1 to 4, and their descriptions are omitted.

[0203] Fig.21 This is an explanatory diagram showing the relationship 1 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region in Example 5. Fig. 22 This is an explanatory diagram showing relationship 2 between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region in Example 5. Fig.21 and Fig. 22 also with Fig.18 Likewise, this is an example in which the number of non-imaging regions 610 is smaller than the number of imaging regions 600 .

[0204] exist Fig.21 In the example, control condition B is set for the imaging area 600-21 and the non-imaging area 610-C1, and control condition A is set for the imaging area 600-22 and the non-imaging area 610-C2.

[0205] and Fig.18 The difference is that in Fig.18 In the example, the control condition of the non-camera region 610-C1 as the reference target non-camera region 1403 of the camera region 600-11 is A. Fig.21 In the example, the control condition of the non-camera area 610-C1 is not A but B. Similarly, in Fig.18 In the example, the control condition of the non-camera area 610-C2 as the reference target non-camera area 1403 of the camera area 600-12 is B. In contrast, Fig.21 In the example, the control condition of the non-camera area 610-C2 is not B but A.

[0206] In addition, Fig. 22In the example, control condition B is set for the imaging area 600-21 and the non-imaging area 610-C1, control condition C is set for the imaging area 600-12, and control condition D is set for the imaging area 600-22 and the non-imaging area 610-C2.

[0207] and Fig.18 The difference is that in Fig.18 In the example, the control condition of the non-camera region 610-C1 as the reference target non-camera region 1403 of the camera region 600-11 is A. Fig. 22 In the example, the control condition of the non-camera area 610-C1 is not A but B. Similarly, in Fig.18 In the example, the control condition of the non-camera area 610-C2 as the reference target non-camera area 1403 of the camera area 600-12 is B. In contrast, Fig. 22 In the example, the control condition of the non-imaging area 610-C2 is not B but D.

[0208] In such a case as well, by appropriately setting the correlation value r, the signal processing unit 810 can perform black level correction with high accuracy using the above-mentioned equation (1).

[0209] As described above, according to the fifth embodiment, black level correction can be performed for each imaging region 600-ij of the imaging pixel region 600 using the non-imaging region 610-Cq outside the imaging pixel region 600 having correlation. Therefore, high-precision black level correction can be achieved for each imaging region 600-ij.

[0210] [Example 6]

[0211] In Example 6, 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 reference numerals are used for the same structures as in Examples 1 to 5, and their description is omitted.

[0212] <Relationship between Control Conditions of the Image-Capturing Pixel Region 600 and Control Conditions of the Optically Black Pixel Region 610>

[0213] use Figure 23-24 The relationship between the control conditions of the imaging pixel region 600 and the control conditions of the optical black pixel region 610 of Example 6 is described. The relationship is as follows: the optical black pixel region 610 is provided in the imaging pixel region 600, and the number of non-imaging regions in the optical black pixel region 610 is less than the number of imaging regions in the imaging pixel region 600. Fig.24 In, pay attention to Fig.23 The differences between Fig.23 Description of the same parts will be omitted.

[0214] Fig.23 1 is an explanatory diagram showing the relationship 1 between the control conditions of the imaging pixel region 600 and the control conditions of the optical black pixel region in Example 6. The imaging region is, for example, a collection of one or more blocks 202. Fig.23 In order to simplify the description, the imaging pixel area 600 is composed of 4 rows and 4 columns of imaging areas 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 area 600 can also be composed of m rows and n columns (m and n are integers greater than 1. There are more than two imaging areas 600) other than 4 rows and 4 columns. When the imaging areas 600-11 to 600-14, 600-21 to 600-24, 600-31 to 600-34, and 600-41 to 600-44 are not distinguished, they are expressed as imaging areas 600-ij.

[0215] The optical black pixel area 610 is composed of a plurality of non-imaging areas 610-11, 610-13, 610-22, 610-24, 610-31, 610-33, 610-42, and 610-44 that do not capture the subject. When the non-imaging areas 610-11, 610-134, 610-122, 610-24, 610-31, 610-33, 610-42, and 610-44 are not distinguished, they are expressed as non-imaging areas 610-ij. The non-imaging areas 610-ij are provided in the imaging area 600-ij that exists in the i-th row and the j-th column.

[0216] The positional relationship between the imaging area 600-ij and the non-imaging area 610-ij will be described in detail. As described above, each imaging area 600-ij has a structure in which the imaging pixels 6 are arranged in a two-dimensional shape. The imaging pixels 6 of each imaging area 600-ij have, for example, the same configuration as that of the non-imaging area 610-ij. Figure 2 The same structure as described in block 202 can control each imaging area 600-ij with different control conditions. In the structure shown in Example 6, there are imaging areas 600-ij with non-imaging areas 610-ij configured therein and imaging areas 600-ij without non-imaging areas 610-ij configured therein.

[0217] exist Fig.23 In the structure shown in FIG. 1 , a closed area 60 is considered, which includes all the imaging pixels 6 of the imaging area 600-11 and is connected to the control line (TX wiring 307, etc.) of the imaging area 600-11, and is determined in such a way that the outer edge has the shortest length. In this case, a non-imaging area 610-11 is arranged inside the closed area 60. Fig.23In the structure shown, a closed area 60 is considered, which includes all the imaging pixels 6 of the imaging area 600-121 connected to the control line (TX wiring 307, etc.) of the imaging area 600-12, and is determined in such a way that the outer edge has the shortest length. In this case, the non-imaging area 610-ij is not arranged inside the closed area 60.

[0218] Like this, Fig.23 The structure shown includes imaging areas (imaging area 600-11, imaging area 600-13, imaging area 600-22, etc.) in which non-imaging areas 610-ij are arranged, and imaging areas (imaging area 600-12, imaging area 600-14, imaging area 600-21, etc.) in which non-imaging areas 610-ij are not arranged.

[0219] By having such a structure, in the imaging area 600-ij in which the non-imaging area 610-ij is arranged, high-precision black level correction is performed in the "reference source imaging area 600-ij" and the "reference target non-imaging area 610-pq" based on the strong correlation with dark current, etc. In addition, in the imaging area 600-ij in which the non-imaging area 610-ij is not arranged, black level correction is performed using the output signal of the non-imaging area 610-ij arranged in the adjacent imaging area 600-ij. As a result, so-called defective pixels are not generated. Therefore, high quality can be ensured for the image generated by the imaging pixel 6 of the imaging area 600-ij.

[0220] like Fig.23 As shown, the imaging regions 600-ij including the optically black pixel regions 610 are discretely arranged. The imaging regions 600-ij including the optically black pixel regions 610 are arranged, for example, in a staggered manner. The optically black pixel regions 610 are arranged, for example, in a staggered manner within the imaging pixel region 600. If the number of imaging regions including the non-imaging regions 610-ij is less than the number of imaging regions 600-ij, the configuration is not limited to the staggered configuration.

[0221] A non-camera region 610-ij includes a PD optical black pixel group and a PD-free optical black pixel group. The optical black pixel region 610 has a PD optical black pixel group and a PD-free optical black pixel group. In addition, the number of camera regions including the non-camera region 610-ij is less than the number of camera regions 600-ij. Fig.23 In the figure, the number of non-image-taking areas 610 - ij is eight, and the number of image-taking areas 600 - ij is sixteen.

[0222] Next, the control conditions set for the imaging pixel area 600 and the optical black pixel area 610 are described. Control conditions are set for each imaging area 600-ij and each non-imaging area 610-ij. The control conditions for the non-imaging area 610-ij are the same as the control conditions for the imaging area 600-ij including the non-imaging area 610-ij. For example, if the control condition for the non-imaging area 610-11 is B, the control condition for the imaging area 600-11 including the non-imaging area 610-11 is also B.

[0223] In addition, although not expressed by a dotted line with black circles at both ends, the non-imaging area 610-ij sets the imaging area 600-ij including the non-imaging area 610-ij as the "reference source imaging area 600-ij". Therefore, for example, the non-imaging area 610-11 is a reference target imaging area of ​​the imaging area 600-11 including the non-imaging area 610-11, and is also a reference target imaging area of ​​the imaging area 600-12 that does not include the non-imaging area 610-11.

[0224] The pixel groups arranged in the row direction are selected at the same timing in units of the row selection circuit or block 202, and pixel signals are output. Therefore, the reference source imaging area 600-ij and the reference target non-imaging area 610-ij are considered to have a correlation related to dark current, etc. Therefore, in the case of performing black level correction on the output signal from the reference source imaging area 600-ij, by subtracting the output signal from the reference source imaging area 600-ij from the output signal from the reference target non-imaging area 610-ij, high-precision black level correction corresponding to the reference source imaging area 600-ij can be achieved.

[0225] In addition, a dashed line with black circles at both ends indicates that in the column direction, the image region 600-ij where the black circle is located refers to the control condition of the non-image region 610-ij. In addition, although not expressed by a dashed line with black circles at both ends, the non-image region 610-ij uses the image region 600-ij including the non-image region 610-ij as the "reference source image region 600-ij". Therefore, for example, the non-image region 610-31 is a reference target image region of the image region 600-31 including the non-image region 610-31, and is also a reference target image region of the image region 600-21 not including the non-image region 610-31.

[0226] The pixel groups arranged in the column direction are connected to a common column readout line and output analog signals in units of blocks 202, which are converted into digital signals by a common A / D converter. Therefore, the reference source imaging area 600-ij and the reference target non-imaging area 610-ij are considered to have a correlation related to dark current, etc. Therefore, in the case of performing black level correction on the output signal from the reference source imaging area 600-ij, by subtracting the output signal from the reference source imaging area 600-ij using the output signal from the reference target non-imaging area 610-ij, high-precision black level correction corresponding to the reference source imaging area 600-ij can be achieved.

[0227] As described above, the number of non-imaging areas 610-ij is less than the number of imaging areas 600-ij. Therefore, one non-imaging area 610-ij can correspond to more than one imaging area 600-ij in black level correction. In addition, for the imaging area 600-ij, it can be preset which direction of the non-imaging area 610-ij in the row direction and the column direction is set as the reference target. In addition, it can also be set according to the control conditions of each imaging area 600-ij and each non-imaging area 610-pq. Alternatively, for the imaging area 600-ij, the larger one, the smaller one or the average value of the output signals of the non-imaging area 610-pq in the row direction and the column direction can also be used.

[0228] In addition, by providing the non-imaging area 600-ij within the imaging area 600-ij, the optical black pixel area can be prevented from being arranged outside the imaging pixel area 600, thereby preventing the imaging element from becoming larger. In addition, since the optical black pixel area can be prevented from being arranged outside the imaging pixel area 600, the area of ​​the imaging pixel area 600 can be increased accordingly.

[0229] Fig.24 This 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 the sixth embodiment. Fig.24 also with Fig.23 Similarly, this is an example in which the number of non-image capture areas 610-ij is greater than the number of image capture areas 600-ij. Fig.24 In the four imaging regions 600-22, 600-23, 600-32, and 600-33 located in the center of the imaging pixel region 600, no non-imaging region 610-ij is provided.

[0230] The reason is that the main subject image is reflected in the center of the imaging pixel area 600, and the image plane phase difference detection pixels focusing on the main subject are more present 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.

[0231] The non-image region 610-ij becomes a defective pixel in the image generation, so interpolation is required, and the possibility of image quality degradation increases. Therefore, the non-image region 610-ij may not be arranged near the central region where the possibility of the main subject is high, or the non-image region 610-ij arranged outside the central region may be set to be more than the non-image region 610-ij arranged in the central region. In addition, the non-image region 610-ij may be increased as it moves away from the central region to the outside.

[0232] Furthermore, the non-imaging region 610-ij may be provided at an end edge of the imaging pixel region 600 (outside the imaging region 600-ij) or an imaging region 600-ij closer to the end edge than the center of the imaging pixel region 600. In addition, not limited to the center of the imaging pixel region 600, the non-imaging region 610-ij may be provided at an imaging region 600-ij where the number of image plane phase difference detection pixels in the imaging pixel region 600 is less than a predetermined number, or may be provided at an imaging region 600-ij where the number of image plane phase difference detection pixels in the imaging pixel region 600 is relatively small.

[0233] <Circuit Structure of Imaging Pixel Region 600 and Optical Black Pixel Region 610>

[0234] The circuit structure of the imaging pixel region 600 and the optical black pixel region 610 in the row direction is as follows: Fig. 9 As shown, the circuit structure of the imaging pixel area 600 and the optical black pixel area 610 in the column direction is as follows Fig.10 shown.

[0235] In addition, the signal processing unit 710 can interpolate the signal at the position of the PD-free optical black pixel 201-3 using the signal output from the imaging pixel 201-1 existing around the PD-free optical black pixel 201-3. The interpolation method used by the signal processing unit 710 can use an interpolation method based on median processing, an interpolation method based on gradient, or an adaptive color plane interpolation method. In addition, the same is true for the image plane phase difference detection pixel.

[0236] <Calibration table>

[0237] Fig.252500 is an explanatory diagram showing an example of a correction table according to Example 6. The correction table 2500 is a table in which a correlation value 1405 is set for each combination of a reference source imaging region 1401 , a reference source control condition 1402 , a reference target non-imaging region 1403 , and a reference target control condition 1404 .

[0238] In the reference source imaging region 1401, the reference source imaging region 600-ij is stored as a value. In the reference source control condition 1402, the control condition of the reference source imaging region 600-ij is stored as a value. In the reference target non-imaging region 1403, the non-imaging region 610-Lp serving as the reference target of the reference source imaging region 600-ij is stored as a value. In the reference target control condition 1404, the control condition of the non-imaging region 610-ij is stored as a value.

[0239] In the correlation value 1405, a value representing the correlation between the reference source imaging area 1401 in which the reference source control condition 1402 is set and the reference target non-imaging area 1403 in which the reference target control condition 1404 is set is stored as a value (correlation value r(ijX, ijY). X is the reference source control condition 1402, and Y is the reference target control condition 1404).

[0240] In addition, there is also a case where the correlation value r(ijX, ijY) is 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 target non-imaging area 1403 is, and the farther away from 1.0, the lower the correlation between the reference source imaging area 1401 and the reference target non-imaging area 1403 is.

[0241] Here, the output from the optical black pixel with PD or the output from the optical black pixel without PD in the reference target non-imaging area 610 - ij is denoted as Q, and the corrected noise component is denoted as P. The relationship between P and Q is expressed by the above equation (1).

[0242] The correlation value r becomes a value close to 1.0 when the reference target non-imaging area 1403 includes the reference source imaging area 1401. Fig.23 In the case where the reference source imaging region 1401 is the imaging region 600-11, if the reference target non-imaging region 1403 is the non-imaging region 610-11, the correlation value r becomes a value closer to 1.0 than when the reference target non-imaging region 1403 is the non-imaging region 610-12. This is because when the reference target non-imaging region 1403 includes the reference source imaging region 1401, the data is read out using the same column readout line.

[0243] If the reference source imaging region 1401 and the reference target non-imaging region 1403 are in the same row, the correlation value r becomes close to 1.0. Fig.23 In the case where the reference source imaging region 1401 is the imaging region 600-11, if the reference target non-imaging region 1403 is the non-imaging region 610-11, the correlation value r becomes closer to 1.0 than when the reference target non-imaging region 1403 is the non-imaging region 610-22. This is because if they are the same row, they are read out with the column readout line at the same timing.

[0244] In addition, the closer the reference source imaging area 1401 and the reference target non-imaging area 1403 are, the closer the correlation value r becomes to 1.0. Fig.23 In the case where the reference source imaging area 1401 is the imaging area 600-11, if the reference target non-imaging area 1403 is the non-imaging area 610-12, the correlation value r becomes closer to 1.0 than when the reference source imaging area 1401 is the imaging area 600-14. This is because it is believed that the closer the pixel positions are, the more similar their characteristics are.

[0245] In addition, if the reference source control condition 1402 is the same as the reference target control condition 1404, the correlation value r becomes a value close to 1.0. Specifically, for example, when the reference source control condition 1402 and the reference target control condition 1404 are the same type of control conditions with different values, the correlation value r becomes a value closer to 1.0 than when the reference source control condition 1402 and the reference target control condition 1404 are different types. This is because the more the control conditions are the same type, the more similar the operation conditions of the reference source imaging area 1401 and the operation conditions of the reference target non-imaging area 1403 are.

[0246] As described above, according to the seventh embodiment, black level correction can be performed for each imaging region 600-ij of the imaging pixel region 600 using the non-imaging region 610-pq outside the imaging pixel region 600 having correlation. Therefore, high-precision black level correction can be achieved for each imaging region 600-ij.

[0247] [Example 7]

[0248] <Relationship between control conditions of imaging pixel area and control conditions of optical black pixel area>

[0249] Next, the relationship between the control conditions of the imaging pixel region and the control conditions of the optical black pixel region in Example 7 is described. Example 7 is a structure in which an optical black pixel region 610 is provided in addition to the imaging pixel region 600 in Example 6. The same reference numerals are attached to the same parts as in Example 6, and the description thereof is omitted.

[0250] Fig.26 1 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 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) is described.

[0251] The internal optical black pixel area 610 is composed of a plurality of internal non-imaging areas 610-11 to 610-14, 610-21, 610-24, 610-31, 610-34, 610-41, and 610-44 that do not capture the subject. When the internal non-imaging areas 610-11 to 610-14, 610-21, 610-24, 610-31, 610-34, 610-41, and 610-44 are not distinguished, they are expressed as internal non-imaging areas 610-ij. The internal non-imaging area 610-ij is provided in the imaging area 600-ij that exists in the i-th row and the j-th column.

[0252] exist Fig.26 , an imaging region 600 is shown in which internal optical black pixel regions 610 are arranged, for example, in a staggered manner within the imaging pixel region 600. If the number of internal non-imaging regions 610-ij is less than the number of imaging regions 600-ij, the arrangement is not limited to the staggered arrangement.

[0253] An internal non-camera area 610-ij includes a PD optical black pixel group and a PD-free optical black pixel group. The optical black pixel area 610 has a PD optical black pixel group and a PD-free optical black pixel group. The PD optical black pixel group is a collection of PD optical black pixels. The PD optical black pixel is a black pixel having PD104. Specifically, for example, the PD optical black pixel is a pixel having a light shielding layer that shields the incident light of the subject.

[0254] In addition, the number of the internal non-image-capturing areas 610-ij is less than the number of the image-capturing areas 600-ij. Fig.26 In the figure, the number of internal non-image-taking areas 610 - ij is 12, and the number of image-taking areas 600 - ij is 16.

[0255] Next, the optical black pixel region 610 existing outside the imaging pixel region 600 (hereinafter referred to as the external optical black pixel region 610 ) will be described.

[0256] The external optical black pixel area 610 is composed of a plurality of external non-imaging areas 610-L1 to 610-L2 and 610-C1 to 610-C2 that do not capture the subject. Fig.26 In the example, two are used) to represent the external non-imaging region group existing in the column direction. When the external non-imaging region group existing in the column direction is not distinguished, it is expressed as the external non-imaging region 610-Lp.

[0257] Multiple external non-camera areas 610-C1 to 610-C2 (in Fig.26 In the example, two are used) as an external non-imaging area group existing in the row direction. When the non-imaging area group existing in the row direction is not distinguished, it is expressed as an external non-imaging area 610-Cq. When multiple external non-imaging areas 610-L1~610-L2, 610-C1~610-C2 are not distinguished, it is expressed as an external non-imaging area 610-pq. Similar to the internal non-imaging area 610-ij, an external non-imaging area 610-pq includes a PD optical black pixel group and a PD-free optical black pixel group.

[0258] The outer optical black pixel region 610 is adjacent to the outer portion of the imaging pixel region 600, similarly to the inner optical black pixel region 610. Fig.26 As an example, the external optical black pixel region 610 is disposed at the right end and the lower end of the imaging pixel region 600. The configuration position of the external optical black pixel region 610 can be at least one of the upper end, the lower end, the right end and the left end of the imaging pixel region 600.

[0259] The external optical black pixel region 610 has a PD optical black pixel group and a PD-free optical black pixel group, similarly to the internal optical black pixel region 610. In addition, the number of the external non-imaging regions 610-pq is, for example, greater than the number of imaging regions 600-ij where the internal non-imaging regions 600-ij do not exist. Fig.26 In the example, the number of the external non-imaging areas 610 - pq is four, and the number of the imaging areas 600 - ij is four.

[0260] Next, a description will be given of control conditions set for the imaging pixel region 600 and the optical black pixel region 610. The 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.

[0261] For example, control condition B is set for the imaging areas 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 for the imaging areas 600-22, 600-23, 600-32, and 600-33.

[0262] The control condition of the internal non-imaging area 610-ij is the same as the control condition of the imaging area 600-ij including the internal non-imaging area 610-ij. For example, the control condition of the internal non-imaging area 610-11 is B, and the control condition of the imaging area 600-11 including the internal non-imaging area 610-11 is also B. For example, the control condition A is set for the external non-imaging areas 610-L1, 610-L2, 610-C1, and 610-C2.

[0263] The dotted line with black circles at both ends indicates that the imaging area 600-ij and the non-imaging area 610-pq where the black circle is located correspond to each other in the row direction in the black level correction. The imaging area 600-ij where the black circle is located is called the "reference source imaging area 600-ij" for black level correction, and the non-imaging area 610-pq where the black circle is located is called the "reference target non-imaging area 610-pq" for black level correction (the same is true for the single-point dashed line with black circles at both ends described later).

[0264] Although not expressed by a dotted line or a dashed line with black circles at both ends, the internal non-imaging area 610-ij uses the imaging area 600-ij including the internal non-imaging area 610-ij as the "reference source imaging area 600-ij". Therefore, for example, the internal non-imaging area 610-11 is the reference target imaging area of ​​the imaging area 600-11 including the internal non-imaging area 610-11.

[0265] The pixel groups arranged in the row direction are selected at the same timing in units of row selection circuits or blocks 202, and pixel signals are output. Therefore, the reference source imaging area 600-ij and the reference target external non-imaging area 610-Lp are considered to have a correlation related to dark current, etc. The same is true between the reference source imaging area 600-ij and the reference target internal non-imaging area 610-ij. Therefore, in the case of performing black level correction on the output signal from the reference source imaging area 600-ij, by using the output signal of the reference target external non-imaging area 610-Lp or the reference target internal non-imaging area 610-ij to subtract the output signal from the reference source imaging area 600-ij, it is possible to achieve high-precision black level correction corresponding to the reference source imaging area 600-ij.

[0266] In addition, a dashed line with black circles at both ends indicates that the imaging region 600 - ij where the black circles are located refers to the control conditions of the external non-imaging region 610 -Cq in the column direction.

[0267] The pixel groups arranged in the column direction are connected to a common column readout line and output analog signals respectively, which are converted into digital signals by a common A / D converter. Therefore, the reference source imaging area 600-ij and the reference target external non-imaging area 610-Cq are considered to have a correlation related to dark current, etc. The same is true between the reference source imaging area 600-ij and the reference target internal non-imaging area 610-ij.

[0268] Therefore, when performing black level correction on the output signal from the reference source camera area 600-ij, high-precision black level correction corresponding to the reference source camera area 600-ij can be achieved by subtracting the output signal from the reference source camera area 600-ij using the output signal of the reference target external non-camera area 610-Cq or the reference target internal non-camera area 610-ij.

[0269] As described above, the number of internal non-imaging areas 610-ij is less than the number of imaging areas 600-ij. Therefore, one internal non-imaging area 610-ij can correspond to more than one imaging area 600-ij in black level correction. In addition, for the imaging area 600-ij, it can be preset which direction of the external non-imaging area 610-pq in the row direction and the column direction is set as the reference target. In addition, it can also be set according to the control conditions of each imaging area 600-ij and each non-imaging area 610-pq. Alternatively, for the imaging area 600-ij, the larger one, the smaller one or the average value of the output signals of the non-imaging area 610-pq in the row direction and the column direction can also be used.

[0270] In particular, Fig.26 In the above, each imaging area 600-ij at the center of the imaging pixel area 600 uses the external non-imaging area 610-pq as a reference target, and each imaging area 600-ij around the center uses the internal non-imaging area 610-ij present in the imaging area 600-ij as a reference target. The reason is that the main subject image is reflected in the center of the effective imaging area 600, and the image plane phase difference detection pixels focusing on the main subject are more present 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.

[0271] <Calibration table>

[0272] Fig. 272700 is an explanatory diagram showing 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 region 1401 , a reference source control condition 1402 , a reference target non-imaging region 1403 , and a reference target control condition 1404 .

[0273] In the reference source imaging region 1401, the reference source imaging region 600-ij is stored as a value. In the reference source control condition 1402, the control condition of the reference source imaging region 600-ij is stored as a value. In the reference target non-imaging region 1403, the internal non-imaging region 610-ij or the external non-imaging region 610-pq that is the reference target of the reference source imaging region 600-ij is stored as a value. In the reference target control condition 1404, the control condition of the internal non-imaging region 610-ij or the external non-imaging region 610-pq is stored as a value.

[0274] In the correlation value 1405, a value representing the correlation between the reference source imaging area 1401 in which the reference source control condition 1402 is set and the reference target non-imaging area 1403 in which the reference target control condition 1404 is set is stored as a value (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 target control condition 1404).

[0275] In addition, there are cases where the correlation value r(ijX, ijY), the correlation value r(ijX, LpY), or the correlation value r(ijX, CqY) is 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 target non-imaging area 1403 is, and the farther away from 1.0, the lower the correlation between the reference source imaging area 1401 and the reference target non-imaging area 1403 is.

[0276] Here, the output signal from the reference target internal non-imaging region 610-ij or the reference target external non-imaging region 610-pq is denoted as Q, and the corrected noise component is denoted as P. The relationship between P and Q is expressed by the above equation (1).

[0277] When the reference target non-image capturing area 1403 includes the reference source image capturing area 1401, the correlation value r becomes a value close to 1.0. Fig.26In the case where the reference source imaging region 1401 is the imaging region 600-11, if the reference target non-imaging region 1403 is the non-imaging region 610-11, the correlation value r becomes a value closer to 1.0 than when the reference target non-imaging region 1403 is the non-imaging region 610-12. This is because when the reference target non-imaging region 1403 includes the reference source imaging region 1401, the data is read out using the same column readout line.

[0278] If the reference source imaging region 1401 and the reference target non-imaging region 1403 are in the same row, the correlation value r becomes close to 1.0. Fig.26 In the case where the reference source imaging region 1401 is the imaging region 600-11, if the reference target non-imaging region 1403 is the non-imaging region 610-11, the correlation value r becomes closer to 1.0 than when the reference target non-imaging region 1403 is the non-imaging region 610-22. This is because if they are the same row, they are read out with the column readout line at the same timing.

[0279] In addition, the closer the reference source imaging region 1401 is to the reference target non-imaging region 1403, the closer the correlation value r is to 1.0. Fig.26 In the case where the reference source imaging region 1401 is the imaging region 600-11, if the reference target non-imaging region 1403 is the non-imaging region 610-12, the correlation value r becomes closer to 1.0 than when the reference source imaging region 1401 is the imaging region 600-14. This is because it is believed that the closer the pixel positions are, the more similar their characteristics are.

[0280] In addition, if the reference source control condition 1402 and the reference target control condition 1404 are the same, the correlation value r becomes a value close to 1.0. Specifically, for example, when the reference source control condition 1402 and the reference target control condition 1404 are the same type of control conditions but different values, the correlation value r becomes a value closer to 1.0 than when the reference source control condition 1402 and the reference target control condition 1404 are different types. This is because it is considered that the more the control conditions are of the same type, the more similar the operation conditions of the reference source imaging area 1401 and the operation conditions of the reference target non-imaging area 1403 are.

[0281] As described above, according to the seventh embodiment, black level correction can be performed for each imaging region 600-ij of the imaging pixel region 600 using the non-imaging region 610-pq outside the imaging pixel region 600 having correlation. Therefore, high-precision black level correction can be achieved for each imaging region 600-ij.

[0282] In addition, the present invention is not limited to the above contents, and any combination thereof is possible. In addition, other solutions that can be conceived within the technical concept of the present invention are also included in the scope of the present invention.

Claims

1. An imaging element, characterized in that: It has multiple camera areas and multiple light-shielding pixel areas. The plurality of imaging areas include: a plurality of first pixels, which include a first photoelectric conversion unit that receives light from an optical system and converts it into electric charge and a first circuit unit connected to the first photoelectric conversion unit, and are arranged in a first direction and a second direction intersecting the first direction; and a first control line that is connected to the plurality of first pixels and outputs a signal for controlling the plurality of first pixels, The plurality of light-shielded pixel regions include: a plurality of second pixels, which include a light-shielded second photoelectric conversion unit and a second circuit unit connected to the second photoelectric conversion unit, and are arranged in the first direction and the second direction; and a second control line, which is connected to the plurality of second pixels and outputs a signal for controlling the second pixels, The light-shielding pixel region is arranged outside the plurality of imaging regions.

2. An imaging element, characterized in that: have: An imaging area including a first area for imaging a subject and generating image data, and a second area different from the first area for imaging the subject and generating image data; as well as a first light shielding region disposed outside the imaging region and having light-shielded pixels, and a second light shielding region different from the first light shielding region and having light-shielded pixels, Different imaging conditions can be set for the first area, the second area, the first light-shielding area, and the second light-shielding area.

3. A camera device, characterized in that: It has an imaging element and a signal processing unit. The imaging element includes an imaging region having a photoelectric conversion unit that performs photoelectric conversion on light from a subject, and a light-shielding pixel region having a photoelectric conversion unit that is shielded from light. The signal processing unit corrects the signal from the photoelectric conversion unit in the imaging area based on the signal from the photoelectric conversion unit in the shading pixel area and a second control condition set for the shading pixel area, wherein the second control condition is different from the first control condition set for the imaging area.

4. A camera device, characterized in that: It has an imaging element and a signal processing unit. The imaging element includes an imaging region having a photoelectric conversion unit that performs photoelectric conversion on light from a subject, and a light-shielding pixel region having a photoelectric conversion unit that is shielded from light. The signal processing unit corrects the signal from the photoelectric conversion unit in the imaging area based on the signal from the photoelectric conversion unit in the shading pixel area and a second control condition set for the shading pixel area, wherein the second control condition is different from the first control condition set for the imaging area.

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