WO2020202413A1

WO2020202413A1 - Image capture element and image capture device

Info

Publication number: WO2020202413A1
Application number: PCT/JP2019/014397
Authority: WO
Inventors: 優森岡; 昌也 ▲高▼橋
Original assignee: 株式会社ニコン
Priority date: 2019-03-29
Filing date: 2019-03-29
Publication date: 2020-10-08

Abstract

[Solution] An image capture element according to the invention comprises: a first image capture area that has a plurality of first pixels including a first photoelectric conversion unit and a first circuit unit and arranged in a first direction and in a second direction intersecting with the first direction and also has a first control line connected to the plurality of first pixels; a second image capture area that has a plurality of second pixels including a second photoelectric conversion unit and a second circuit unit and arranged in the first direction and in the second direction and also has a second control line connected to the plurality of second pixels; and third pixels including a third light-shielded photoelectric conversion unit and a third circuit unit, wherein the first image capture area incorporates all the first pixels that are connected to the first control line and possessed by the first image capture area and has the third pixels within a closed area the outer edges of which are determined to have the shortest length, while the second image capture area incorporates all the second pixels that are connected to the second control line and possessed by the second image capture area and has none of the third pixels within a closed area the outer edges of which are determined to have the shortest length.

Description

Image sensor and image sensor

The present invention relates to an image pickup device and an image pickup device.

Patent Document 1 discloses a charge coupling element having an optical black region in which a photodiode is arranged and an optical black region in which a photodiode is not arranged. However, the charge coupling element of Patent Document 1 does not consider a plurality of imaging regions in which different imaging conditions are set.

Japanese Unexamined Patent Publication No. 2006-303856

The imaging element of the present disclosure technology includes a first photoelectric conversion unit that receives light from an optical system and converts it into a charge, and a first circuit unit that is connected to the first photoelectric conversion unit, and includes a first direction and the first. A plurality of first pixels arranged in a second direction intersecting one direction, a first control line connected to the plurality of first pixels and outputting a signal for controlling the plurality of first pixels, and A first imaging region having the above, a second photoelectric conversion unit that receives light from an optical system and converts it into a charge, and a second circuit unit connected to the second photoelectric conversion unit, the first direction and the said. A second imaging having a plurality of second pixels arranged in the second direction and a second control line connected to the plurality of second pixels and output a signal for controlling the plurality of second pixels. The first imaging region includes a region, a third pixel that includes a light-shielded third photoelectric conversion unit and a third circuit unit connected to the third photoelectric conversion unit, and the first imaging region is the first control line. The third pixel is included inside all the first pixels of the first imaging region connected to, and the third pixel is inside a closed region specified so that the outer edge has the shortest length. The second imaging region is specified so as to include all the second pixels of the second imaging region connected to the second control line and to have the shortest outer edge. The third pixel is not provided inside the closed region.
The image pickup device of the present disclosure technology has a plurality of imaging regions composed of a group of pixels for imaging a subject, imaging conditions are set for each of the plurality of imaging regions, and two types are provided in the plurality of imaging regions. It is composed of an effective pixel region in which the above imaging conditions are set and a first optical black pixel group in the effective pixel region, and has a plurality of first non-imaging regions smaller than the imaging region. Each of the first non-imaging regions has a first optical black pixel region in which the same or different imaging conditions as the reference source imaging region are set.

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

<Structure example of image sensor>
The image pickup device mounted on the electronic device shown in the examples of the present specification is a stacked image pickup device. In this stacked image sensor, different imaging conditions (control conditions) can be set for each of a plurality of different imaging regions. First, the structure of the stacked image sensor in which different image pickup conditions (control conditions) can be set for each of a plurality of different image pickup regions will be described. It should be noted that this laminated image sensor is described in Japanese Patent Application No. 2012-139026, which the applicant of the present application filed earlier. The electronic device is, for example, an imaging device such as a digital camera or a digital video camera.

FIG. 1 is a cross-sectional view of the stacked image sensor 100. The stacked image sensor (hereinafter, simply “imaging element”) 100 processes a back-illuminated image pickup chip (hereinafter, simply “imaging chip”) 113 that outputs a pixel signal corresponding to incident light, and a pixel signal. It includes a signal processing chip 111 and a memory chip 112 that stores pixel signals. The imaging chip 113, the signal processing chip 111, and the memory chip 112 are laminated and electrically connected to each other by a conductive bump 109 such as Cu.

As shown in FIG. 1, the incident light is mainly incident in the Z-axis plus direction indicated by the white arrow. In the present embodiment, in the image pickup chip 113, the surface on the side where the incident light is incident is referred to as the back surface. Further, as shown in the coordinate axis 120, the left direction of the paper surface orthogonal to the Z axis is defined as the X-axis plus direction, and the Z-axis and the front direction of the paper surface orthogonal to the X-axis are defined as the Y-axis plus direction. In some subsequent figures, the coordinate axes 120 are displayed so that the orientation of each figure can be understood with reference to the coordinate axes 120 of FIG.

An example of the image pickup chip 113 is a back-illuminated MOS (Metal Oxide Semiconductor) image sensor. The PD (photodiode) layer 106 is arranged on the back surface side of the wiring layer 108. The PD layer 106 has a plurality of PD 104s arranged two-dimensionally and accumulating charges according to incident light, and a transistor 105 provided corresponding to the PD 104.

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

A microlens 101 is provided on the incident side of the incident light in the color filter 102 corresponding to each pixel. The microlens 101 collects incident light toward the corresponding PD 104.

The wiring layer 108 has a wiring 107 that transmits a pixel signal from the PD layer 106 to the signal processing chip 111. The wiring 107 may have multiple layers, and may be provided with passive elements and active elements.

A plurality of bumps 109 are arranged on the surface of the wiring layer 108. The plurality of bumps 109 are aligned with the plurality of bumps 109 provided on the facing surfaces of the signal processing chip 111, and the imaging chip 113 and the signal processing chip 111 are aligned by being pressurized or the like. The bumps 109 are joined together and electrically connected.

Similarly, a plurality of bumps 109 are arranged on the surfaces of the signal processing chip 111 and the memory chip 112 facing each other. These bumps 109 are aligned with each other, and the signal processing chip 111 and the memory chip 112 are pressurized, so that the aligned bumps 109 are joined to each other and electrically connected.

Note that the bonding between the bumps 109 is not limited to Cu bump bonding by solid phase diffusion, but micro bump bonding by solder melting may be adopted. Further, for example, about one bump 109 may be provided for one block described later. Therefore, the size of the bump 109 may be larger than the pitch of the PD 104. Further, in the peripheral region other than the pixel region in which the pixels are arranged, a bump larger than the bump 109 corresponding to the pixel region may be provided together.

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 TSV 110 is preferably provided in the peripheral region. Further, the TSV 110 may also be provided in the peripheral area of the image pickup chip 113 and the memory chip 112.

FIG. 2 is a diagram illustrating a pixel arrangement of the imaging chip 113. In particular, the state in which the image pickup chip 113 is observed from the back surface side is shown. (A) is a plan view schematically showing an imaging surface 200 which is the back surface of the imaging chip 113, and (b) is an enlarged plan view of a part area 200a of the imaging surface 200. As shown in (b), a large number of pixels 201 are arranged two-dimensionally on the imaging surface 200.

Each pixel 201 has a color filter (not shown). The color filter consists of three types of red (R), green (G), and blue (B), and the notations "R", "G", and "B" in (b) are the color filters of pixel 201. Represents the type of. As shown in (b), on the image pickup surface 200 of the image pickup device 100, pixels 201 having such color filters are arranged according to a so-called Bayer array.

The pixel 201 having a red filter photoelectrically converts the incident light in the red wavelength band and outputs a light receiving signal (photoelectric conversion signal). Similarly, the pixel 201 having a green filter photoelectrically converts the incident light in the green wavelength band and outputs a received signal. Further, the pixel 201 having a blue filter photoelectrically converts the incident light in the blue wavelength band and outputs a received signal.

The image sensor 100 is configured to be individually controllable for each block 202 composed of a total of four pixels 201 of two adjacent pixels × 2 pixels. For example, when two blocks 202 different from each other start charge accumulation at the same time, one block 202 reads out the charge, that is, reads out the received light signal 1/30 second after the start of charge accumulation, and the other block 202 reads out the received signal. The charge can be read out 1/15 second after the start of charge accumulation. In other words, the image sensor 100 can set a different exposure time (charge accumulation time, so-called shutter speed) for each block 202 in one image pickup.

The image sensor 100 can make the amplification factor (so-called ISO sensitivity) of the image pickup signal different for each block 202 in addition to the above-mentioned exposure time. The image sensor 100 can change the timing of starting charge accumulation and the timing of reading a received signal for each block 202. That is, the image sensor 100 can change the frame rate at the time of moving image imaging for each block 202.

Summarizing the above, the image sensor 100 is configured so that the image pickup conditions (control conditions) such as the exposure time, amplification factor, and frame rate can be made different for each block 202. For example, if a reading line (not shown) for reading an image pickup signal from a photoelectric conversion unit (not shown) included in the pixel 201 is provided for each block 202, and the image pickup signal can be read out independently for each block 202, The exposure time (shutter speed) can be made different for each block 202.

Further, if an amplifier circuit (not shown) that amplifies the image pickup signal generated by the photoelectrically converted charge is provided independently for each block 202, the amplification factor by the amplifier circuit can be controlled independently for each amplifier circuit. , The signal amplification factor (ISO sensitivity) can be made different for each block 202.

In addition to the above-mentioned imaging conditions (control conditions), the imaging conditions (control conditions) that can be made different for each block 202 include the frame rate, gain, resolution (thinning rate), and the number of lines to be added to add the pixel signals. Or the number of addition columns, charge accumulation time or number of times, digitization bits, etc. Further, the control parameter may be a parameter in image processing after acquiring an image signal from a pixel.

Further, as for the image pickup condition (control condition), for example, a liquid crystal panel having a section that can be independently controlled for each block 202 (one section corresponds to one block 202) is provided in the image pickup element 100, and the image sensor 100 can be turned on and off. If it is used as an optical filter, the brightness (aperture value) can be controlled for each block 202.

The number of pixels 201 constituting the block 202 does not have to be the above-mentioned 2 × 2 4 pixels. The block 202 may have at least two or more pixels 201, and conversely, may have more than four pixels 201.

FIG. 3 is a circuit diagram of the imaging chip 113. In FIG. 3, a rectangle typically surrounded by a dotted line represents a circuit corresponding to one pixel 201. Further, the rectangle surrounded by the alternate long and short dash line corresponds to one block 202 (202-1 to 202-4). It should be noted that at least a part of each transistor described below corresponds to the transistor 105 of FIG.

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

Similarly, the 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. Further, the TX wiring 307-3 for supplying the transfer pulse to the four transfer transistors 302 corresponding to the block 202-3 is provided separately from the TX wiring 307-1.

Similarly, for the upper right block 202-2 and the lower right block 202-4, reset wiring 300-2 and TX wiring 307-2, and reset wiring 300-4 and TX wiring 307-4 are provided in each block 202, respectively. Has been

The 16 PD 104s corresponding to each pixel 201 are connected to the corresponding transfer transistors 302, respectively. A transfer pulse is supplied to the gate of each transfer transistor 302 via the TX wiring for each block 202. The drain of each transfer transistor 302 is connected to the source of the corresponding reset transistor 303, and 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. To.

The drain of each reset transistor 303 is commonly connected to the Vdd wiring 310 to which the power supply voltage is supplied. A reset pulse is supplied to the gate of each reset transistor 303 via the reset wiring for each block 202.

The drain of each amplification transistor 304 is commonly connected to the Vdd wiring 310 to which the power supply voltage is supplied. Also, the source of each amplification transistor 304 is connected to the drain of the corresponding selection transistor 305. The gate of each selection transistor 305 is connected to a decoder wiring 308 to which a selection pulse is supplied. The decoder wiring 308 is provided independently for each of the 16 selection transistors 305.

Then, the source of each selection transistor 305 is connected to the 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 the source follower. The load current source 311 may be provided on the imaging chip 113 side or the signal processing chip 111 side.

Here, the flow from the start of charge accumulation to the pixel output after the end of accumulation will be described. When a reset pulse is applied to the reset transistor 303 through the reset wiring for each block 202, and at the same time, a transfer pulse is applied to the transfer transistor 302 through the TX wiring for each block 202 (202-1 to 202-4), the block Every 202, the potentials of PD104 and floating diffusion FD are reset.

When the application of the transfer pulse is released, each PD 104 converts the received incident light into an electric charge and accumulates it. After that, when the transfer pulse is applied again while the reset pulse is not applied, the accumulated charge is transferred to the floating diffusion FD, and the potential of the floating diffusion FD changes from the reset potential to the signal potential after charge accumulation. ..

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

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 transfer pulse are simultaneously applied to the four pixels in the block 202, respectively. Therefore, all the pixels 201 forming a certain block 202 start the charge accumulation at the same timing and end the 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.

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

FIG. 4 is a block diagram showing a configuration example of the image sensor 100. The analog multiplexer 411 sequentially selects 16 PD 104s forming the block 202, and outputs each pixel signal to the output wiring 309 provided corresponding to the block 202. The multiplexer 411 is formed on the imaging chip 113 together with the PD 104.

The pixel signal output via the multiplexer 411 is CDS and A / by a signal processing circuit 412 formed on the signal processing chip 111, which performs correlated double sampling (CDS) and analog / digital (A / D) conversion. D conversion is performed. The A / D converted pixel signal is passed 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 on the memory chip 112.

The arithmetic circuit 415 processes the pixel signal stored in the pixel memory 414 and hands it over to the image processing unit in the subsequent stage. The arithmetic circuit 415 may be provided on the signal processing chip 111 or the memory chip 112. Although FIG. 4 shows the connections for the four blocks 202, in reality, these exist for each of the four blocks 202 and operate in parallel.

However, the arithmetic circuit 415 does not have to exist for each of the four blocks 202. For example, one arithmetic circuit 415 sequentially refers to the values of the pixel memory 414 corresponding to each of the four blocks 202 for processing. You may.

As described above, output wiring 309 is provided corresponding to each of the blocks 202. Since the image sensor 100 has an image pickup chip 113, a signal processing chip 111, and a memory chip 112 stacked on top of each other, by using an electrical connection between the chips using bumps 109 for these output wirings 309, each chip is placed in the plane direction. Wiring can be routed without making it large.

<Example of block configuration of electronic device>
FIG. 5 is an explanatory diagram showing an example of a block configuration of an electronic device. The electronic device 500 is, for example, a camera with a built-in lens. The electronic device 500 includes an image pickup optical system 501, an image pickup element 100, a control unit 502, a liquid crystal monitor 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 that detects camera shake and subject blur as described later.

The image pickup optical system 501 is composed of a plurality of lenses, and forms a subject image on the image pickup surface 200 of the image pickup element 100. In FIG. 5, for convenience, the imaging optical system 501 is shown as a single lens.

The image sensor 100 is, for example, an image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device), and outputs an image pickup signal by imaging a subject image imaged by the image pickup optical system 501. The control unit 502 is an electronic circuit that controls each part 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.

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

The liquid crystal monitor 503 is a display device using a liquid crystal panel. The control unit 502 causes the image sensor 100 to repeatedly image the subject image at predetermined intervals (for example, 1/60 second). Then, various image processes are applied to the image pickup signal output from the image pickup element 100 to create a so-called through image, which is displayed on the liquid crystal monitor 503. In addition to the above-mentioned through image, the liquid crystal monitor 503 displays, for example, a setting screen for setting imaging conditions (control conditions).

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

The recording unit 508 is composed of, for example, a microphone, converts an environmental sound into an audio signal, and inputs it to the control unit 502. The control unit 502 does not record the moving image file on the memory card 504, which is a portable recording medium, but a recording medium (not shown) such as an SSD (Solid State Drive) or a hard disk built in the electronic device 500. It may be recorded in.

The parts common to each of the following examples have been described with reference to FIGS. 1 to 5 above. Hereinafter, the image pickup device and the image pickup apparatus according to each embodiment will be described.

In the first embodiment, the number of non-imaging regions in the optical black pixel region is equal to or greater than the number of imaging regions in the imaging pixel region, and the non-imaging regions are arranged at positions different from the imaging pixel regions. Be prepared.

<Relationship between the control condition of the imaging pixel area and the control condition of the optical black pixel area>
Next, 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 according to the first embodiment will be described with reference to FIGS. 6, 10, and 11. To do. In FIGS. 10 and 11, since the differences from FIG. 6 will be focused on, the same parts as those in FIG. 6 will be omitted.

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

The imaging region is, for example, a set of one or more blocks 202. In FIG. 6, for simplification of the description, the imaging pixel region 600 is composed of two rows and two columns of imaging regions 600-11, 600-12, 600-21, and 600-22. However, the imaging pixel area 600 may be composed of m rows and n columns other than 2 rows and 2 columns (m and n are integers of 1 or more, but the imaging region 600 is 2 or more). When the imaging regions 600-11, 600-12, 600-21, and 600-22 are not distinguished, they are referred to as imaging regions 600-ij. Each imaging region 600-ij can be controlled under different control conditions from the other imaging regions 600-ij.

The optical black pixel region 610 is composed of a plurality of non-imaging regions 610-L1-610-L4 and 610-C1-610-C4 that do not image the subject. Each of the non-imaging regions 610-L1-610-L4 and 610-C1-610-C4 includes, for example, at least one of a PD-less optical black pixel group and a PD-bearing optical black pixel group, which will be described later.

The PD-less optical black pixel group or the PD-bearing optical black pixel group in each of the non-imaging regions 610-L1-610-L4 and 610-C1-610-C4 is, for example, the same as the block 202 described with reference to FIG. In addition, each pixel is provided in a two-dimensionally arranged configuration. The optical black pixel group without PD or the optical black pixel group with PD has a configuration that can be controlled under different control conditions for each of the non-imaging regions 610-L1-610-L4 and 610-C1-610-C4. Be prepared.

Here, in each embodiment, the non-imaging region including the PD-less optical black pixel group is also referred to as a light-shielding pixel region. The plurality of non-imaging regions 610-L1 to 610-L4 are non-imaging regions existing in the column direction. When the non-imaging region group existing in the column direction is not distinguished, it is expressed as the non-imaging region 610-Lp. The plurality of non-imaging regions 610-C1 to 610-C4 are groups of non-imaging regions existing in the row direction.

When the non-imaging area group existing in the row direction is not distinguished, it is expressed as the non-imaging area 610-Cq. When a plurality of non-imaging regions 610-L1-610-L4 and 610-C1-610-C4 are not distinguished, they are referred to as non-imaging regions 610-pq. One non-imaging region 610-pq includes an optical black pixel group with PD and an optical black pixel group without PD.

The optical black pixel region 610 is adjacent to the outside of the imaging pixel region 600. In FIG. 6, as an example, the optical black pixel region 610 is provided at the right end and the lower end of the image pickup pixel region 600. The position of the optical black pixel region 610 may be at least one of the upper end, the lower end, the right end, and the left end of the imaging pixel region 600.

The optical black pixel region 610 includes an optical black pixel group with PD and an optical black pixel group without PD. The group of optical black pixels with PD is a set of optical black pixels with PD. The optical black pixel with PD is a black pixel having PD 104. Specifically, for example, an optical black pixel with PD is a pixel having a light-shielding layer that blocks the incident light of a subject.

The PD-less optical black pixel group is a set of PD-less optical black pixels. The PD-less optical black pixel is a black pixel having no PD 104. By subtracting the output signal from the optical black pixel with PD or the output signal from the optical black pixel without PD from the output signal from the imaging pixel, black level correction is executed and noise such as dark current components is removed. To.

Further, the number of non-imaging regions 610-pq is equal to or greater than the number of imaging regions 600-ij. In FIG. 6, the number of non-imaging regions 610-pq is eight, and the number of imaging regions 600-ij is four.

In addition, the non-imaging area 610-Cq is arranged in 2 rows and 2 columns. The non-imaging regions 610-C1 and 610-C3 are arranged in the column direction, and the PD-free optical black pixel group in the non-imaging region 610-C1 and the PD-less optical black pixel group in the non-imaging region 610-C3. And are adjacent. Similarly, the non-imaging regions 610-C2 and 610-C4 are arranged in the column direction, and the PD-free optical black pixel group in the non-imaging region 610-C2 and the PD-less optical in the non-imaging region 610-C4 are arranged. Is adjacent to the black pixel group. As described above, since the PD-less optical black pixel group in the non-imaging region 610-Cq is not separated, the number of arrangements of the PD-less optical black pixel group can be reduced, and the manufacturing cost can be reduced.

<Circuit configuration of imaging pixel area 600 and optical black pixel area 610>
FIG. 7 is a circuit diagram showing a circuit configuration of an imaging pixel region 600 and an optical black pixel region 610 in the row direction according to the first embodiment. FIG. 8 is a circuit diagram showing a circuit configuration of an imaging pixel region 600 and an optical black pixel region 610 in the column direction according to the first embodiment. In FIGS. 7 and 8, the pixel 201 of the image pickup pixel area 600 is defined as the image pickup pixel 201-1, and the pixel 201 of the optical black pixel area 610 is the optical black pixel 201-2 with PD and the optical black pixel 201 without PD. Let it be -3.

The pixel 201 has a transfer transistor 302, a reset transistor 303, an amplification transistor 304, a selection transistor 305, and a floating diffusion FD. The imaging pixel 201-1 further includes a red (R), G (green), or blue (B) color filter 102 and a PD 104. The PD-presence optical black pixel 201-2 further has a light-shielding layer 700 and a PD 104. The PD-less optical black pixel 201-3 has neither a filter nor a PD 104.

The imaging pixel 201-1 generates an electric charge according to the amount of light incident on the color filter 102. On the other hand, since the optical black pixel 201-2 with PD has a light-shielding layer 700, it does not generate an electric charge according to the amount of incident light, but it generates an electric charge corresponding to thermal noise.

When the control signals TX_C and TX_O1 from the drive circuit 711 are given to the gate of the transfer transistor 302 of the imaging pixel 211-1 and the optical black pixel 201-2 with PD, the charge accumulated in PD 104 is transferred to the floating diffusion FD. Forward. The transfer transistor 302 of the optical black pixel 201-3 without PD does not generate an electric charge due to PD 104 even if the control signal TX_O2 from the drive circuit 711 is given to the gate thereof.

When the control signal RST from the drive circuit 711 is given to the gate of the reset transistor 303, the potential of the floating diffusion FD is set to substantially the same potential as Vdd. For example, the reset transistor 303 eliminates the electrons accumulated in the floating diffusion FD.

When the control signals SEL_C, SEL_O1 and SEL_O2 from the drive circuit 711 are given to the gate of the selection transistor 305, the selection transistor 304 outputs a current to the column readout lines 701 to 703 at the amplified voltage. The column read lines 701-1 to 701-4 in FIG. 8 correspond to the column read lines 701 in FIG.

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

The signal processing unit 710 inputs a signal corresponding to the amount of charge photoelectrically converted in the imaging pixel 211-1. The signal processing unit 710 inputs a signal corresponding to the thermal noise detected in the optical black pixel 201-2 with PD. The signal processing unit 710 uses the signal from the PD-less optical black pixel 201-3 as a reference for the black level of the imaging pixel 201-1.

The signal processing unit 710 subtracts the output signal from the optical black pixel 201-2 with PD or the output signal from the optical black pixel 201-3 without PD from the output signal from the imaging pixel 201-1. Perform black level correction. As a result, noise such as dark current is removed. The signal processing unit 710 may be realized by a circuit, or may be realized by the processor executing a program stored in the memory.

The drive circuit 711 (not shown in FIG. 8) supplies control signals TX, RST, and SEL as signal pulses to the gates of the transfer transistor 302, the reset transistor 303, and the selection transistor 305. As a result, the transfer transistor 302, the reset transistor 303, and the selection transistor 305 are turned on.

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

<Timing chart showing the operation of block 202>
FIG. 9 is a timing chart showing the operation of the block 202 according to the first embodiment. The drive circuit 711 controls the transfer transistor 302 and the reset transistor 303 at the same timing in one block 202. However, with respect to the pixel 201 provided with the color filter 102 having the same spectral characteristics, the drive circuit 711 shifts the timing for each pixel 201 to output the pixel signal from the selection transistor 305.

For example, the drive circuit 711 turns on each reset transistor 303 (RST) of one block 202 at time t2. As a result, the potential of the gate of each amplification transistor 304 is reset. The drive circuit 711 keeps each reset transistor 303 (RST) in the ON state from time t2 to time t5.

The drive circuit 711 turns on all the transfer transistors 302 in one block 202 at time t3. As a result, first, the electric charge accumulated in the PD 104 existing in the block 202 is reset.

The drive circuit 711 turns off each reset transistor 303 (RST) at time t5. The drive circuit 711 then turns on all the transfer transistors 302 in one block 202 again at time t7. As a result, the charges accumulated in the PD 104 existing in one block 202 are transferred to the corresponding floating diffusion FDs, respectively.

During the period from time t3 to time t7, the pixel 201 having the PD 104 in one block 202 accumulates electric charges. That is, the period from time t3 to time t7 is the charge accumulation period of the pixel 201 having the PD 104.

The drive circuit 711 turns on the transfer transistors 302 in sequence after time t8. In this example, at time t8, the charges accumulated in the PD 104 in one block 202 are transferred to, for example, the column readout lines 701 to 703, respectively.

Further, at time t9, the charges accumulated in the other PD 104 in the other block 202 are transferred to the column read lines 701 to 703, respectively. The transfer operation is executed for each pixel 201 in one block 202. As a result, the pixel signals of each pixel 201 included in one block 202 are output to the column readout lines 701 to 703, respectively.

Returning to FIG. 6, the positional relationship between the imaging region 600-ij and the non-imaging region 610-pq will be described. As described above, each imaging region 600-ij has a configuration in which imaging pixels 6 are arranged in a two-dimensional manner. The imaging pixels 6 in each imaging region 600-ij have, for example, the same configuration as the block 202 described with reference to FIG. 2, and each imaging region 600-ij can be controlled under different control conditions.

Here, all the imaging pixels 6 of the imaging region 600-ij, which are connected to the control line (TX wiring 307, etc.) of each imaging region 600-ij, are included inside, and the outer edge has the shortest length. Consider a closed region 60 specified to be. The non-imaging region 610-pq is located outside this closed region 60. By providing such a configuration, the imaging pixels 6 can be uniformly arranged inside each imaging region 600-ij. Therefore, it is possible to ensure high quality for the image generated by the imaging pixels 6 in each imaging region 600-ij without the occurrence of so-called defective pixels.

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

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

The dotted lines with black circles at both ends indicate that the imaging area 600-ij where the black circles are located and the non-imaging area 610-pq correspond in the black level correction in the row direction. The imaging area 600-ij where the black circles are located is the "reference source imaging area 600-ij" for black level correction, and the non-imaging area 610-pq where the black circles are located is the "referenced non-imaging area 610-pq" for black level correction. (The same applies to the alternate long and short dash line with black circles on both ends, which will be described later).

Pixel groups arranged in the row direction are selected at the same timing in the row selection circuit or block 202 unit, and a pixel signal is output. Therefore, it is considered that the reference source imaging region 600-ij and the reference destination non-imaging region 610-pq have a correlation with respect to dark current and the like. Therefore, when the output signal from the reference source imaging region 600-ij is corrected for black level, the output signal from the reference source imaging region 600-ij is subtracted by using the output signal of the reference destination non-imaging region 610-pq. This makes it possible to perform highly accurate black level correction according to the reference source imaging region 600-ij.

Further, the alternate long and short dash line with black circles at both ends indicates that the imaging region 600-ij in which the black circles are located and the non-imaging region 610-pq correspond to each other in the black level correction. The pixel groups arranged in the column direction are connected to a common column readout line to output an analog signal, and are converted into a digital signal by a common A / D converter.

Therefore, it is considered that the reference source imaging region 600-ij and the reference destination non-imaging region 610-pq have a correlation with respect to dark current and the like. Therefore, when correcting the black level of the output signal from the reference source imaging region 600-ij, the output signal from the reference source imaging region 600-ij is subtracted by using the output signal from the reference destination non-imaging region 610-pq. By doing so, it is possible to perform highly accurate black level correction according to the reference source imaging region 600-ij.

As described above, the number of non-imaging regions 610-pq is equal to or greater than the number of imaging regions 600-ij. Therefore, one imaging region 600-ij can correspond to one or more non-imaging regions 610-pq in black level correction. In the black level correction, it may be set in advance whether to use the output signal of the non-imaging region 610-pq in the row direction or the column direction with respect to the imaging region 600-ij, and each imaging. It may be set according to the control conditions of the region 600-ij and each non-imaging region 610-pq. Alternatively, the larger, smaller, or average value of the output signals of the non-imaging region 610-pq in both the row direction and the column direction may be adopted with respect to the imaging region 600-ij.

Further, in the above-described example, the “reference source imaging region 600-ij” and the “reference destination non-imaging region 610-pq” are selected at the same timing in the row selection circuit or block 202 unit, or are common A. An example of converting to a digital signal by a / D converter is shown, but the present invention is not limited to this. For example, "reference source imaging region 600-ij" and "reference destination non-imaging region 610-pq" are not selected at the same timing in the row selection circuit or block 202 unit, and digital signals are used by a common A / D converter. It may be a configuration that is not converted to.

Even with such a configuration, the “reference source imaging region 600-ij” and the “reference destination non-imaging region 610-pq” are controlled under the same control conditions, so that the “reference source imaging region 600-ij” is used. Since there is a correlation between "" and "reference destination non-imaging region 610-pq" regarding dark current and the like, the output signal from the reference source imaging region 600-ij and the output signal from the reference destination non-imaging region 610-pq are used. By using and subtracting, highly accurate black level correction according to the reference source imaging region 600-ij becomes possible.

FIG. 10 is an explanatory diagram showing the relationship 2 between the control condition of the imaging pixel region and the control condition of the optical black pixel region according to the first embodiment. FIG. 10 is also an example in which the number of non-imaging regions 610 is equal to or greater than the number of imaging regions 600, which is the same as that of FIG. In FIG. 10, the non-imaging regions 610-C2, 610-L6, 610-C7, 610-C8 are replaced with the non-imaging regions 610-C2, 610-L4, 610-C2, 610-C4 shown in FIG. The configuration arranged in the direction is shown.

Control condition A is set in the non-imaging regions 610-C5 and 610-L6, and control condition B is set in the non-imaging regions 610-C7 and 610-L8. The correspondence between the reference source imaging region 600-ij and the reference non-imaging region 610-pq is as shown by the alternate long and short dash lines with black circles at both ends and the alternate long and short dash line with black circles at both ends, as in FIG. Since the non-imaging regions 610-C5, 610-L6, 610-C7, 610-C8 are arranged in only one row in the row direction, the area of the imaging pixel region 600 can be increased as compared with FIG.

FIG. 11 is an explanatory diagram showing the relationship 3 between the control condition of the imaging pixel region and the control condition of the optical black pixel region according to the first embodiment. FIG. 11 is also an example in which the number of non-imaging regions 610 is equal to or greater than the number of imaging regions 600, which is the same as that of FIG. In FIG. 11, control condition A is set in the imaging region 600-11, control condition B is set in the imaging region 600-12, control condition C is set in the imaging region 600-21, and the imaging region 600- The control condition D is set in 22.

Further, in FIG. 11, instead of the non-imaging region 610-C2,610-L4,610-C2,610-C4 shown in FIG. 6, the non-imaging region 610-C5, 610-L6, 610-C7, 610-C8 Indicates a configuration in which is arranged in the row direction. Control condition A is set in the non-imaging area 610-C5, control condition C is set in the non-imaging area 610-L6, control condition B is set in the non-imaging area 610-C5, and the non-imaging area 610- Control condition D is set in C8.

Further, the control condition A is set in the non-imaging region 610-L1, the control condition B is set in the non-imaging region 610-L2, the control condition C is set in the non-imaging region 610-L3, and the non-imaging region is set. The control condition D is set in 610-L4.

Control conditions A to D are different control conditions. Further, the correspondence relationship between the reference source imaging region 600-ij and the reference destination non-imaging region 610-pq is as shown by the alternate long and short dash line with black circles at both ends and the alternate long and short dash line with black circles at both ends, as in FIG.

Since the non-imaging regions 610-C5, 610-L6, 610-C7, 610-C8 are arranged in only one row in the row direction, the area of the imaging pixel region 600 can be increased as compared with FIG. Further, the number of different control conditions can be set up to the number of imaging regions. In FIGS. 6, 10 and 11, the number of imaging regions 600 is four, but in FIGS. 6 and 10, the number of different control conditions is two, A and B.

On the other hand, in FIG. 11, four different control conditions, A to D, are set. In this way, it is possible to set the number of control conditions in proportion to the number of imaging regions 600. Therefore, various control conditions can be combined, and the degree of freedom in shooting can be improved.

<Other examples of optical black pixel 201-2 with PD>
FIG. 12 is a block diagram showing another example of the optical black pixel 201-2 with PD according to the first embodiment. In the optical black pixel 201-4 with PD, the output of PD104 is connected to the input of PD104. The configuration is the same as that shown in FIGS. 7 and 8 except that the ground is short-circuited between the PD 104 and the transfer transistor 302.

Therefore, the electric charge due to photoelectric conversion is basically not accumulated in PD104. Even if the electric charge is accumulated in the PD 104, the electric charge is not read out as a pixel signal, but the electric charge due to a dark current or the like is accumulated in the floating diffusion FD.

As described above, according to the first embodiment, the black level correction is performed for each of the imaging regions 600-ij of the imaging pixel region 600 by using the non-imaging region 610-pq outside the correlated imaging pixel region 600. It becomes possible to execute. Therefore, it is possible to improve the accuracy of the black level correction for each of the imaging regions 600-ij.

Further, all the imaging pixels 6 of the imaging region 600-ij, which are connected to the control line (TX wiring 307, etc.) of each imaging region 600-ij, are included inside, and the outer edge has the shortest length. Consider a closed region 60 as specified. The non-imaging region 610-pq is located outside this closed region 60. This makes it possible to uniformly arrange the imaging pixels 6 inside each imaging region 600-ij. Therefore, it is possible to ensure high quality for the image generated by the imaging pixels 6 in each imaging region 600-ij without the occurrence of so-called defective pixels.

Example 2 has a relationship in which the number of non-imaging regions in the optical black pixel region, which will be described later, is smaller than the number of imaging regions in the imaging pixel region. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

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

The optical black pixel region 610 is adjacent to the outside of the imaging pixel region 600. In FIG. 13, as an example, it is provided at the right end of the imaging pixel region 600. The position of the optical black pixel region 610 may be at least one of the right end and the left end of the image pickup pixel region 600. Further, the number of non-imaging regions 610-Lp is smaller than the number of imaging regions 600-ij. In FIG. 13, the number of non-imaging regions 610-Lp is two, and the number of imaging regions 600-ij is four.

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

Similar to FIG. 6, the dotted lines of the black circles at both ends indicate that the imaging region 600-ij where the black circles are located and the non-imaging region 610-pq correspond in the black level correction in the row direction. The imaging area 600-ij where the black circles are located is the "reference source imaging area 600-ij" for black level correction, and the non-imaging area 610-pq where the black circles are located is the "referenced non-imaging area 610-pq" for black level correction. (The same applies to the alternate long and short dash line with black circles on both ends, which will be described later).

Pixel groups arranged in the row direction are selected at the same timing in the row selection circuit or block 202 unit, and a pixel signal is output. Therefore, it is considered that the reference source imaging region 600-ij and the reference destination non-imaging region 610-Lp have a correlation with respect to dark current and the like. Therefore, when correcting the black level of the output signal from the reference source imaging region 600-ij, the output signal from the reference source imaging region 600-ij is subtracted by using the output signal from the reference destination non-imaging region 610-Lp. By doing so, the black level can be corrected according to the reference source imaging region 600-ij.

As described above, the number of non-imaging regions 610-Lp is smaller than the number of imaging regions 600-ij. Therefore, one imaging region 600-ij can correspond to one or more non-imaging regions 610-Lp in black level correction. Further, although the black level correction is performed for each line, it may be performed for each area. That is, each signal level in the imaging region 600-11 may be corrected by the average value of the signal outputs in the non-imaging region 610-L1.

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

The correlation value 1405 is a value (correlation value) indicating the correlation between the reference source imaging region 1401 in which the reference source control condition 1402 is set and the reference destination non-imaging region 1403 in which the reference destination control condition 1404 is set. r (ijX, LpY). X is the reference source control condition 1402, and Y is the reference destination control condition 1404.) Is stored.

Note that the correlation value r (ijX, LpY) may simply be 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 region 1401 and the reference destination non-imaging region 1403, and the farther away from 1.0, the higher the correlation between the reference source imaging region 1401 and the reference destination non-imaging region 1401. It shows that the correlation with the region 1403 is low.

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

P = r × Q + b ... (1)

B is an adjustment value that is arbitrarily set, and is a value that is determined for each image sensor 100. The calculation using the above equation (1) is executed by, for example, the signal processing unit 810 described later.

The correlation value r tends to be close to 1.0 if the reference source imaging region 1401 and the reference destination non-imaging region 1403 are in the same row. For example, in FIG. 13, when the reference source imaging region 1401 is the imaging region 600-11 and the reference non-imaging region 1403 is the non-imaging region 610-L1, the reference non-imaging region 1403 is the non-imaging region 610-L2. Compared with the case of, the correlation value r is closer to 1.0. This is because if the rows are the same, they are read by the column reading line at the same timing.

Further, the correlation value r tends to be closer to 1.0 as the reference source imaging region 1401 and the reference destination non-imaging region 1403 are closer to each other. For example, in FIG. 13, when the reference source imaging region 1401 is the imaging region 600-12, the reference destination non-imaging region 1403 is the non-imaging region 610-L1, and the reference source imaging region 1401 is the imaging region 600-11. The correlation value r is close to 1.0. This is because it is considered that the closer the pixel positions are, the more similar their characteristics are.

Further, if the correlation value r is the same as the reference source control condition 1402 and the reference destination control condition 1404, it becomes a value close to 1.0. Specifically, for example, when the reference source control condition 1402 and the reference destination control condition 1404 are the same type but have different values, the reference source control condition 1402 and the reference destination control condition 1404 are different from each other. , The correlation value r is close to 1.0. This is because if the control conditions are the same, the operating conditions of the reference source imaging region 1401 and the operating conditions of the reference non-imaging region 1403 are the same.

The noise component correction target using the correlation value r may be limited to the reference source imaging region 1401 which is not adjacent to the reference non-imaging region 1403. For example, when the reference destination non-imaging region 1403 is the non-imaging region 610-L1, the reference source imaging region 1401 becomes the imaging region 600-11. In this case, since the imaging region 600-12 is adjacent to the imaging region 610-L1, it is not set in the reference source imaging region 1401. As a result, the image area to be corrected is limited, so that the data in the correction table 1400 becomes small.

<Circuit configuration of imaging pixel area 600 and optical black pixel area 610>
FIG. 15 is a circuit diagram showing a circuit configuration of an imaging pixel region 600 and an optical black pixel region 610 in the column direction. The circuit configurations of the imaging pixel region 600 and the optical black pixel region 610 in the row direction are the same as those in FIG. In FIGS. 11 and 15, the pixel 201 of the imaging pixel area 600 is defined as the imaging pixel 201-1, and the pixel 201 of the optical black pixel region 610 is the optical black pixel 201-2 with PD and the optical black pixel 201 without PD. Let it be -3.

When the control signals SEL_C, SEL_O1 and SEL_O2 from the drive circuit 811 are given to the gate of the selection transistor 305, the selection transistor 304 outputs a current to the column readout lines 701 to 703 at the amplified voltage. The column read lines 1503-1 to 1503-4 in FIG. 15 correspond to the column read lines 703 in FIG.

As described above, according to the second embodiment, for each of the imaging regions 600-ij of the imaging pixel region 600, black level correction is performed using the non-imaging region 610-Lp that correlates with the imaging region 600-ij. It becomes possible to execute. Therefore, it is possible to improve the accuracy of the black level correction for each of the imaging regions 600-ij.

Example 3 will be described. In the second embodiment, the image sensor in which the same control conditions are set in the same row is shown, but in the third embodiment, the image sensor in which the same control conditions are set in the same row is shown. The same configurations as those in the first and second embodiments are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 16 is an explanatory diagram showing the relationship 1 between the control condition of the imaging pixel region and the control condition of the optical black pixel region according to the third embodiment. FIG. 17 is an explanatory diagram showing the relationship 2 between the control condition of the imaging pixel region and the control condition of the optical black pixel region according to the third embodiment. 16 and 17 are similar to FIG. 13, and are examples in which the number of non-imaging regions 610 is smaller than the number of imaging regions 600.

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

The difference from FIG. 13 is that in FIG. 13, the control condition of the non-imaging region 610-L1, which is the reference non-imaging region 1403 of the imaging region 600-11, is A, whereas in FIG. 16, the non-imaging region is The point is that the control condition of 610-L1 is B instead of A. Similarly, in FIG. 13, the control condition of the non-imaging region 610-L2, which is the reference non-imaging region 1403 of the imaging region 600-21, is A, whereas in FIG. 16, the control of the non-imaging region 610-L2 is controlled. The condition is A instead of B.

Further, in FIG. 17, control condition B is set in the imaging region 600-12 and the non-imaging region 610-L1, control condition C is set in the imaging region 600-21, and the imaging region 600-22 and the non-imaging region are set. Control condition D is set in 610-L2.

The difference from FIG. 13 is that in FIG. 13, the control condition of the non-imaging region 610-L1, which is the reference non-imaging region 1403 of the imaging region 600-11, is A, whereas in FIG. 17, the non-imaging region is The point is that the control condition of 610-L1 is B instead of A. Similarly, in FIG. 13, the control condition of the non-imaging region 610-L2, which is the reference non-imaging region 1403 of the imaging region 600-21, is A, whereas in FIG. 17, the control condition of the non-imaging region 610-L2 is A. Is not A but D.

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

As described above, according to the third embodiment, black level correction is performed for each of the imaging regions 600-ij of the imaging pixel region 600 by using the non-imaging region 610-Lq outside the correlated imaging pixel region 600. It becomes possible to execute. Therefore, it is possible to improve the accuracy of the black level correction for each of the imaging regions 600-ij.

Example 4 will be described. In the second embodiment, the image sensor in which the same control conditions are set in the same row is shown, but in the fourth embodiment, the image sensor in which the same control conditions are set in the same column is shown. The same configurations as those of Examples 1 to 3 are designated by the same reference numerals, and the description thereof will be omitted.

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

The optical black pixel region 610 is adjacent to the outside of the imaging pixel region 600. In FIG. 18, as an example, it is provided on the lower end side of the imaging pixel region 600. The position of the optical black pixel region 610 may be at least one of the upper end side and the lower end side of the imaging pixel region 600.

Also, the number of non-imaging areas 610-Cq is smaller than the number of imaging areas 600-ij. In FIG. 18, the number of non-imaging regions 610-Cq is two, and the number of imaging regions 600-ij is four.

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

The pixel groups arranged in the column direction are connected to a common column readout line to output analog signals, and are converted into digital signals by a common A / D converter. Therefore, it is considered that the reference source imaging region 600-ij and the reference destination non-imaging region 610-Cq have a correlation (high) with respect to dark current and the like. Therefore, when correcting the black level of the output signal from the reference source imaging region 600-ij, the output signal from the reference source imaging region 600-ij is subtracted by the output signal of the reference destination non-imaging region 610-Cq. , Highly accurate black level correction according to the reference source imaging region 600-ij is possible.

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.

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

The correlation value 1405 is a value (correlation value) indicating the correlation between the reference source imaging region 1401 in which the reference source control condition 1402 is set and the reference destination non-imaging region 1403 in which the reference destination control condition 1404 is set. r (ijX, CqY). X is the reference source control condition 1402, and Y is the reference destination control condition 1404.) Is stored.

Note that the correlation value r (ijX, CqY) may simply be 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 region 1401 and the reference destination non-imaging region 1403, and the farther away from 1.0, the higher the correlation between the reference source imaging region 1401 and the reference destination non-imaging region 1401. It shows that the correlation with the region 1403 is low.

Here, let Q be the output from the optical black pixel with PD or the output from the optical black pixel without PD in the reference non-imaging region 610-Cq, and let P be the noise component after correction. The relationship between P and Q is expressed by the above equation (1).

The correlation value r is close to 1.0 when the reference source imaging region 1401 and the reference destination non-imaging region 1403 are in the same column. For example, in FIG. 18, when the reference source imaging region 1401 is the imaging region 600-11 and the reference non-imaging region 1403 is the non-imaging region 610-C1, the reference non-imaging region 1403 is the non-imaging region 610-C2. Compared with the case of, the correlation value r is closer to 1.0. This is because if they are in the same column, they are read by the same column reading line.

Further, the correlation value r becomes closer to 1.0 as the reference source imaging region 1401 and the reference destination non-imaging region 1403 are closer to each other. For example, in FIG. 18, when the reference source imaging region 1401 is the imaging region 600-21, the reference non-imaging region 1403 is the non-imaging region 610-C1, and the reference source imaging region 1401 is the imaging region 600-11. The correlation value r is close to 1.0. This is because it is considered that the closer the pixel positions are, the more similar their characteristics are.

The noise component correction target using the correlation value r may be limited to the reference source imaging region 1401 which is not adjacent to the reference non-imaging region 1403. For example, when the reference destination non-imaging region 1403 is the non-imaging region 610-C1, the reference source imaging region 1401 becomes the imaging region 600-11.

In this case, since the imaging region 600-21 is adjacent to the imaging region 610-C1, it is not set in the reference source imaging region 1401. As a result, the image area to be corrected is limited, so that the data in the correction table 1900 becomes smaller.

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

When the control signals SEL_C, SEL_O1 and SEL_O2 from the drive circuit 811 are given to the gate of the selection transistor 305, the selection transistor 304 outputs a current to the column readout lines 701 to 703 at the amplified voltage. The column read lines 701-1 to 701-4 in FIG. 10 correspond to the column read

lines

702 and 703 in FIG. 20.

As described above, according to the fourth embodiment, black level correction is performed for each of the imaging regions 600-ij of the imaging pixel region 600 by using the non-imaging region 610-Cq outside the correlated imaging pixel region 600. It becomes possible to execute. Therefore, it is possible to improve the accuracy of the black level correction for each of the imaging regions 600-ij.

Example 5 will be described. In the fourth embodiment, the image sensor in which the same control conditions are set in the same row is shown, but in the fifth embodiment, the image sensor in which different control conditions are set in the same row is shown. The same components as those of Examples 1 to 4 are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 21 is an explanatory diagram showing the relationship 1 between the control condition of the imaging pixel region and the control condition of the optical black pixel region according to the fifth embodiment. FIG. 22 is an explanatory diagram showing the relationship 2 between the control condition of the imaging pixel region and the control condition of the optical black pixel region according to the fifth embodiment. 21 and 22 are also similar to FIG. 18, and are examples in which the number of non-imaging regions 610 is smaller than the number of imaging regions 600.

In FIG. 21, control condition B is set in the imaging region 600-21 and the non-imaging region 610-C1, and control condition A is set in the imaging region 600-22 and the non-imaging region 610-C2.

The difference from FIG. 18 is that in FIG. 18, the control condition of the non-imaging region 610-C1 which is the reference non-imaging region 1403 of the imaging region 600-11 is A, whereas in FIG. 21, the non-imaging region is The control condition of 610-C1 is B instead of A. Similarly, in FIG. 18, the control condition of the non-imaging region 610-C2, which is the reference non-imaging region 1403 of the imaging region 600-12, is B, whereas in FIG. 21, the control of the non-imaging region 610-C2 is controlled. The condition is A instead of B.

Further, in FIG. 22, control condition B is set in the imaging region 600-21 and the non-imaging region 610-C1, control condition C is set in the imaging region 600-12, and the imaging region 600-22 and the non-imaging region are set. Control condition D is set in 610-C2.

The difference from FIG. 18 is that in FIG. 18, the control condition of the non-imaging region 610-C1 which is the reference non-imaging region 1403 of the imaging region 600-11 is A, whereas in FIG. 22, the non-imaging region is The control condition of 610-C1 is B instead of A. Similarly, in FIG. 18, the control condition of the non-imaging region 610-C2, which is the reference non-imaging region 1403 of the imaging region 600-12, is B, whereas in FIG. 22, the control of the non-imaging region 610-C2 is controlled. The condition is D instead of B.

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

As described above, according to the fifth embodiment, the black level correction is performed for each of the imaging regions 600-ij of the imaging pixel region 600 by using the non-imaging region 610-Cq outside the correlated imaging pixel region 600. It becomes possible to execute. Therefore, it is possible to improve the accuracy of the black level correction for each of the imaging regions 600-ij.

Example 6 has a relationship that the number of non-imaging regions in the optical black pixel region, which will be described later, is smaller than the number of imaging regions in the imaging pixel region. The same configurations as those of Examples 1 to 5 are designated by the same reference numerals, and the description thereof will be omitted.

<Relationship between the control condition of the imaging pixel area 600 and the control condition of the optical black pixel area 610>
The relationship between the control condition of the imaging pixel region 600 and the control condition of the optical black pixel region 610 according to the sixth embodiment will be described with reference to FIGS. 23 to 24. In this relationship, 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 smaller than the number of imaging regions in the imaging pixel region 600. It is a relationship. In FIG. 24, since the description will be focused on the differences from FIG. 23, the description of the same parts as those in FIG. 23 will be omitted.

FIG. 23 is an explanatory diagram showing the relationship 1 between the control condition of the imaging pixel region 600 and the control condition of the optical black pixel region according to the sixth embodiment. The imaging region is, for example, a set of one or more blocks 202. In FIG. 23, for simplification of the description, the imaging pixel area 600 has 4 rows and 4 columns of imaging regions 600-11 to 600-14, 600-21 to 600-24, 600-31 to 600-34, 600-. It is composed of 41 to 600-44. However, the imaging pixel area 600 may be composed of m rows and n columns other than 4 rows and 4 columns (m and n are integers of 1 or more, but the imaging region 600 is 2 or more). When the imaging regions 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 referred to as imaging regions 600-ij.

The optical black pixel region 610 is composed of a plurality of non-imaging regions 610-11, 610-13, 610-22, 610-24, 610-31, 610-33, 610-42, and 610-44 that do not image the subject. Will be done. When the non-imaging area 610-11, 610-134, 610-122, 610-24, 610-31, 610-33, 610-42, and 610-44 are not distinguished, it is referred to as the non-imaging area 610-ij. The non-imaging region 610-ij is provided in the imaging region 600-ij existing in rows and columns i.

The positional relationship between the imaging region 600-ij and the non-imaging region 610-ij will be described in detail. As described above, each imaging region 600-ij has a configuration in which imaging pixels 6 are arranged in a two-dimensional manner. The imaging pixels 6 in each imaging region 600-ij have, for example, the same configuration as the block 202 described with reference to FIG. 2, and each imaging region 600-ij can be controlled under different control conditions. In the configuration shown in Example 6, an imaging region 600-ij in which the non-imaging region 610-ij is arranged inside and an imaging region 600-ij in which the non-imaging region 610-ij is not arranged inside are provided. ..

In the configuration shown in FIG. 23, all the imaging pixels 6 of the imaging region 600-11 connected to the control line (TX wiring 307, etc.) of the imaging region 600-11 are included inside, and the outer edge is the shortest. Consider a closed region 60 that is specified to be of length. In this case, the non-imaging region 610-11 is arranged inside the closed region 60. Further, in the configuration shown in FIG. 23, all the imaging pixels 6 of the imaging region 600-121 connected to the control line (TX wiring 307, etc.) of the imaging region 600-12 are included inside, and the outer edge is Consider a closed region 60 that is specified to have the shortest length. In this case, the non-imaging region 610-ij is not arranged inside the closed region 60.

As described above, the configuration shown in FIG. 23 includes an imaging region (imaging region 600-11, imaging region 600-13, imaging region 600-22, etc.) in which the non-imaging region 610-ij is arranged internally, and a non-imaging region. It includes an imaging region (imaging region 600-12, imaging region 600-14, imaging region 600-21, etc.) in which 610-ij is not arranged inside.

By providing such a configuration, in the imaging region 600-ij in which the non-imaging region 610-ij is arranged internally, "reference source imaging region 600-ij" and "reference destination non-imaging region 610-pq" Highly accurate black level correction is performed due to the strong correlation with respect to dark current and the like. Then, in the imaging region 600-ij in which the non-imaging region 610-ij is not arranged inside, the black level is corrected by using the output signal of the non-imaging region 610-ij arranged in the adjacent imaging region 600-ij. Is executed. As a result, so-called defective pixels do not occur. Therefore, it is possible to ensure high quality for the image generated by the imaging pixels 6 in the imaging region 600-ij.

As shown in FIG. 23, the imaging region 600-ij including the optical black pixel region 610 is arranged discretely. The imaging region 600-ij including the optical black pixel region 610 is arranged in a staggered pattern, for example. The optical black pixel region 610 is arranged in a staggered pattern within the imaging pixel region 600, for example. If the number of imaging regions including the non-imaging region 610-ij is less than the number of imaging regions 600-ij, the arrangement is not limited to the staggered arrangement.

One non-imaging region 610-ij includes an optical black pixel group with PD and an optical black pixel group without PD. The optical black pixel region 610 includes an optical black pixel group with PD and an optical black pixel group without PD. Further, the number of imaging regions including the non-imaging region 610-ij is smaller than the number of imaging regions 600-ij. In FIG. 23, the number of non-imaging regions 610-ij is eight, and the number of imaging regions 600-ij is 16.

Next, the control conditions set in the imaging pixel area 600 and the optical black pixel area 610 will be described. Control conditions are set for each imaging region 600-ij and each non-imaging region 610-ij. The control conditions for the non-imaging region 610-ij are the same as the control conditions for the imaging region 600-ij including the non-imaging region 610-ij. For example, the control condition of the non-imaging region 610-11 is B, and the control condition of the imaging region 600-11 including the non-imaging region 610-11 is also B.

Although not indicated by the dotted lines with black circles at both ends, the non-imaging area 610-ij defines 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 region 610-11 is the reference imaging region of the imaging region 600-11 including the non-imaging region 610-11, and the imaging region 600-12 not including the non-imaging region 610-11. It is also a reference imaging area.

Pixel groups arranged in the row direction are selected at the same timing in the row selection circuit or block 202 unit, and a pixel signal is output. Therefore, it is considered that the reference source imaging region 600-ij and the reference destination non-imaging region 610-ij have a correlation with respect to dark current and the like. Therefore, when correcting the black level of the output signal from the reference source imaging region 600-ij, the output signal from the reference source imaging region 600-ij is subtracted from the output signal from the reference destination non-imaging region 610-ij. As a result, highly accurate black level correction according to the reference source imaging region 600-ij becomes possible.

Further, the alternate long and short dash line with black circles at both ends indicates that the imaging region 600-ij where the black circles are located refers to the control condition of the non-imaging region 610-ij in the column direction. Further, although not indicated by the alternate long and short dash line with black circles at both ends, the non-imaging region 610-ij defines the imaging region 600-ij including the non-imaging region 610-ij as the "reference source imaging region 600-ij". Therefore, for example, the non-imaging region 610-31 is the reference imaging region of the imaging region 600-31 including the non-imaging region 610-31, and the imaging region 600-21 not including the non-imaging region 610-31. It is also a reference imaging area.

The pixel groups arranged in the column direction are connected to a common column readout line, output analog signals in units of blocks 202, and are converted into digital signals by a common A / D converter. Therefore, it is considered that the reference source imaging region 600-ij and the reference destination non-imaging region 610-ij have a correlation with respect to dark current and the like. Therefore, when the output signal from the reference source imaging region 600-ij is corrected to the black level, the output signal from the reference source imaging region 600-ij is subtracted by using the output signal from the reference non-imaging region 610-ij. By doing so, it is possible to perform highly accurate black level correction according to the reference source imaging region 600-ij.

As described above, the number of non-imaging regions 610-ij is smaller than the number of imaging regions 600-ij. Therefore, one non-imaging region 610-ij can correspond to one or more imaging regions 600-ij in black level correction. It should be noted that which direction of the non-imaging region 610-ij in the row direction or the column direction is set as the reference destination with respect to the imaging region 600-ij may be set in advance, and each imaging region 600-ij and It may be set according to the control condition of each non-imaging region 610-pq. Alternatively, the larger, smaller, or average value of the output signals of the non-imaging region 610-pq in both the row direction and the column direction may be adopted with respect to the imaging region 600-ij.

Further, since the non-imaging region 600-ij is provided in the imaging region 600-ij, the optical black pixel region does not have to be arranged outside the imaging pixel region 600, so that the image sensor is prevented from becoming large. be able to. Further, since the optical black pixel region does not have to be arranged outside the imaging pixel region 600, the area of the imaging pixel region 600 can be expanded by that amount.

FIG. 24 is an explanatory diagram showing the relationship 2 between the control condition of the imaging pixel region 600 and the control condition of the optical black pixel region 610 according to the sixth embodiment. FIG. 24 is also an example in which the number of non-imaging regions 610-ij is equal to or greater than the number of imaging regions 600-ij, as in FIG. 23. In FIG. 24, the non-imaging region 610-ij is not provided in the four imaging regions 600-22, 600-23, 600-32, 600-33 located in the center of the imaging pixel region 600.

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 that focus the main subject are in the surrounding imaging areas 600-11 to 600-14, 600-21. , 600-24, 600-31,600-34, 600-41-600-44.

Since the non-imaging region 610-ij is a defective pixel in generating an image, interpolation is required and there is a high possibility that the image quality will deteriorate. Therefore, the non-imaging region 610-ij is not arranged in the vicinity of the central region where it is highly likely that the main subject is present, or the non-imaging region 610-ij is arranged outside the central region in the central region. It may be larger than the non-imaging area 610-ij to be arranged. Further, the non-imaging region 610-ij may increase as the distance from the central region increases to the outside.

The non-imaging area 610-ij may be provided at the edge of the imaging pixel area 600 (outside the imaging area 600-ij) or in the imaging area 600-ij closer to the edge than the center of the imaging pixel area 600. Good. Further, the non-imaging region 610-ij may be provided not only in the center of the imaging pixel region 600 but also in the imaging region 600-ij in which the number of pixels of the image plane phase difference detection pixels in the imaging pixel region 600 is a predetermined number or less. The image plane phase difference detection pixel may be provided in the image pickup area 600-ij in which the number of pixels of the image plane phase difference detection pixel is relatively small.

<Circuit configuration of imaging pixel area 600 and optical black pixel area 610>
The circuit configurations of the imaging pixel region 600 and the optical black pixel region 610 in the row direction are as shown in FIG. 9, and the circuit configurations of the imaging pixel region 600 and the optical black pixel region 610 in the column direction are shown in FIG. As shown.

The signal processing unit 710 uses the signal output from the imaging pixel 201-1 existing around the PD-less optical black pixel 201-3 to generate a signal at the position of the PD-less optical black pixel 201-3. It may be interpolated. As the interpolation method used by the signal processing unit 710, an interpolation method by median processing, an interpolation method based on a gradient, or an adaptive color plane interpolation method may be used. The same applies to the image plane phase difference detection pixels.

<Correction table>
FIG. 25 is an explanatory diagram showing an example of the correction table according to the sixth embodiment. The correction table 2500 is a table in which a correlation value 1405 is set for each combination of the reference source imaging region 1401, the reference source control condition 1402, the reference destination non-imaging region 1403, and the reference destination control condition 1404.

The reference source imaging region 600-ij is stored as a value in the reference source imaging region 1401. 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 destination non-imaging region 1403, the non-imaging region 610-Lp which is the reference destination of the reference source imaging region 600-ij is stored as a value. In the reference destination control condition 1404, the control condition of the non-imaging region 610-ij is stored as a value.

The correlation value 1405 is a value (correlation value) indicating the correlation between the reference source imaging region 1401 in which the reference source control condition 1402 is set and the reference destination non-imaging region 1403 in which the reference destination control condition 1404 is set. r (ijX, ijY). X is the reference source control condition 1402, and Y is the reference destination control condition 1404.) Is stored.

Note that the correlation value r (ijX, ijY) may simply be 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 region 1401 and the reference destination non-imaging region 1403, and the farther away from 1.0, the higher the correlation between the reference source imaging region 1401 and the reference destination non-imaging region 1401. It shows that the correlation with the region 1403 is low.

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

The correlation value r is close to 1.0 when the reference destination non-imaging region 1403 includes the reference source imaging region 1401. For example, in FIG. 23, when the reference source imaging region 1401 is the imaging region 600-11 and the reference non-imaging region 1403 is the non-imaging region 610-11, the reference non-imaging region 1403 is the non-imaging region 610-12. Compared with the case of, the correlation value r is closer to 1.0. This is because when the reference destination non-imaging region 1403 includes the reference source imaging region 1401, the reference destination non-imaging region 1403 is read by the same column readout line.

The correlation value r is close to 1.0 if the reference source imaging region 1401 and the reference destination non-imaging region 1403 are in the same row. For example, in FIG. 23, when the reference source imaging region 1401 is the imaging region 600-11 and the reference non-imaging region 1403 is the non-imaging region 610-11, the reference non-imaging region 1403 is the non-imaging region 610-22. Compared with the case of, the correlation value r is closer to 1.0. This is because if the rows are the same, they are read by the column reading line at the same timing.

Further, the correlation value r becomes closer to 1.0 as the reference source imaging region 1401 and the reference destination non-imaging region 1403 are closer to each other. For example, in FIG. 23, when the reference source imaging region 1401 is the imaging region 600-11, the reference non-imaging region 1403 is the non-imaging region 610-12, and the reference source imaging region 1401 is the imaging region 600-14. The correlation value r is close to 1.0. This is because it is considered that the closer the pixel positions are, the more similar their characteristics are.

Further, if the correlation value r is the same as the reference source control condition 1402 and the reference destination control condition 1404, the correlation value r is close to 1.0. Specifically, for example, when the reference source control condition 1402 and the reference destination control condition 1404 are the same type but have different values, the reference source control condition 1402 and the reference destination control condition 1404 are different from each other. , The correlation value r is close to 1.0. This is because it is considered that the more the control conditions are the same, the more similar the operating conditions of the reference source imaging region 1401 and the operating conditions of the reference non-imaging region 1403 are.

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

<Relationship between the control condition of the imaging pixel area and the control condition of the optical black pixel area>
Next, the relationship between the control condition of the imaging pixel region and the control condition of the optical black pixel region according to the seventh embodiment will be described. In the seventh embodiment, the optical black pixel region 610 is provided outside the image pickup pixel region 600 in the sixth embodiment. The same parts as those in the sixth embodiment are designated by the same reference numerals, and the description thereof will be omitted.

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

The internal optical black pixel region 610 includes a plurality of internal non-imaging regions 610-11 to 610-14, 610-21, 610-24, 610-31, 610-34, 610-41, 610-44 that do not image the subject. Consists of. When the internal non-imaging area 610-11 to 610-14, 610-21, 610-24, 610-31, 610-34, 610-41, and 610-44 are not distinguished, it is referred to as the internal non-imaging area 610-ij. .. The internal non-imaging region 610-ij is provided in the imaging region 600-ij existing in rows and columns i.

In FIG. 26, the imaging region 600 in which the internal optical black pixel region 610 is arranged is shown, but the internal optical black pixel region 610 is arranged in a staggered pattern in the imaging pixel region 600, for example. 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.

One internal non-imaging area 610-ij includes an optical black pixel group with PD and an optical black pixel group without PD. The optical black pixel region 610 includes an optical black pixel group with PD and an optical black pixel group without PD. The group of optical black pixels with PD is a set of optical black pixels with PD. The optical black pixel with PD is a black pixel having PD 104. Specifically, for example, an optical black pixel with PD is a pixel having a light-shielding layer that blocks the incident light of a subject.

Also, the number of internal non-imaging areas 610-ij is smaller than the number of imaging areas 600-ij. In FIG. 26, the number of internal non-imaging regions 610-ij is 12, and the number of imaging regions 600-ij is 16.

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

The external optical black pixel region 610 is composed of a plurality of external non-imaging regions 610-L1 to 610-L2 and 610-C1 to 610-C2 that do not image the subject. The plurality of external non-imaging regions 610-L1 to 610-L2 (two as an example in FIG. 26) are groups of external non-imaging regions existing in the column direction. When the external non-imaging region group existing in the column direction is not distinguished, it is expressed as an external non-imaging region 610-Lp.

A plurality of external non-imaging regions 610-C1 to 610-C2 (two as an example in FIG. 26) are external non-imaging regions existing in the row direction. When the non-imaging region group existing in the row direction is not distinguished, it is expressed as an external non-imaging region 610-Cq. When a plurality of external non-imaging regions 610-L1-610-L2 and 610-C1-610-C2 are not distinguished, they are referred to as external non-imaging regions 610-pq. One external non-imaging region 610-pq, like the internal non-imaging region 610-ij, includes an optical black pixel group with PD and an optical black pixel group without PD.

The external optical black pixel region 610 is adjacent to the outside of the imaging pixel region 600, like the internal optical black pixel region 610. In FIG. 26, as an example, the external optical black pixel region 610 is provided at the right end and the lower end of the image pickup pixel region 600. The position of the external optical black pixel region 610 may be at least one of the upper end, the lower end, the right end, and the left end of the imaging pixel region 600.

The external optical black pixel region 610 has an optical black pixel group with PD and an optical black pixel group without PD, similarly to the internal optical black pixel region 610. Further, the number of external non-imaging regions 610-pq is, for example, equal to or greater than the number of imaging regions 600-ij in which the internal non-imaging region 600-ij does not exist. In FIG. 26, the number of external non-imaging regions 610-pq is four, and the number of imaging regions 600-ij is four.

Next, the control conditions set in the imaging pixel area 600 and the optical black pixel area 610 will be described. 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.

For example, control condition B is set in the imaging regions 600-11 to 600-14, 600-211, 600-24, 600-31, 600-34, 600-11 to 600-14, and the imaging region 600-22. , 600-23, 600-32, 600-33, for example, control condition A is set.

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

Further, although not indicated by dotted lines or alternate long and short dash lines at both ends, the internal non-imaging area 610-ij refers to the imaging area 600-ij including the internal non-imaging area 610-ij as "reference source imaging area 600-ij". To do. Therefore, for example, the internal non-imaging region 610-11 is a reference imaging region of the imaging region 600-11 including the internal non-imaging region 610-11.

Pixel groups arranged in the row direction are selected at the same timing in the row selection circuit or block 202 unit, and a pixel signal is output. Therefore, it is considered that the reference source imaging region 600-ij and the reference destination external non-imaging region 610-Lp have a correlation with respect to dark current and the like. The same applies between the reference source imaging region 600-ij and the reference destination internal non-imaging region 610-ij. Therefore, when the black level of the output signal from the reference source imaging region 600-ij is corrected, the output signal from the reference source imaging region 600-ij is used as the reference external non-imaging region 610-Lp or the reference internal non-imaging region. By subtracting using the output signal of 610-ij, highly accurate black level correction according to the reference source imaging region 600-ij becomes possible.

Further, the alternate long and short dash 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.

The pixel groups arranged in the column direction are connected to a common column readout line to output analog signals, and are converted into digital signals by a common A / D converter. Therefore, it is considered that the reference source imaging region 600-ij and the reference destination external non-imaging region 610-Cq have a correlation with respect to dark current and the like. The same applies between the reference source imaging region 600-ij and the reference destination internal non-imaging region 610-ij.

Therefore, when the black level of the output signal from the reference source imaging region 600-ij is corrected, the output signal from the reference source imaging region 600-ij is used as the reference external non-imaging region 610-Cq or the reference internal non-imaging region. By subtracting using the output signal of 610-ij, highly accurate black level correction according to the reference source imaging region 600-ij becomes possible.

As described above, the number of internal non-imaging regions 610-ij is smaller than the number of imaging regions 600-ij. Therefore, one internal non-imaging region 610-ij can correspond to one or more imaging regions 600-ij in black level correction. It should be noted that it may be set in advance whether the external non-imaging region 610-pq in the row direction or the column direction is referred to with respect to the imaging region 600-ij, and each imaging region 600-ij And may be set according to the control conditions of each non-imaging region 610-pq. Alternatively, the larger, smaller, or average value of the output signals of the non-imaging region 610-pq in both the row direction and the column direction may be adopted with respect to the imaging region 600-ij.

In particular, in FIG. 26, each of the imaging regions 600-ij at the center of the imaging pixel region 600 refers to the external non-imaging region 610-pq, and each of the imaging regions 600-ij around the center is an imaging region. The internal non-imaging region 610-ij existing in 600-ij is referred to. The reason is that the main subject image is reflected in the center of the effective imaging region 600, and the image plane phase difference detection pixels that focus the main subject are in the surrounding imaging regions 600-11 to 600-14, 600-21. , 600-24, 600-31,600-34, 600-41-600-44.

<Correction table>
FIG. 27 is an explanatory diagram showing an example of the correction table according to the seventh embodiment. The correction table 2700 is a table in which a correlation value 1405 is set for each combination of the reference source imaging region 1401, the reference source control condition 1402, the reference destination non-imaging region 1403, and the reference destination control condition 1404.

The reference source imaging region 600-ij is stored as a value in the reference source imaging region 1401. 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 destination non-imaging region 1403, the internal non-imaging region 610-ij or the external non-imaging region 610-pq, which is the reference destination of the reference source imaging region 600-ij, is stored as a value. In the reference destination 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.

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

Note that the correlation value r (ijX, ijY), the correlation value r (ijX, LpY), or the correlation value r (ijX, CqY) may be simply referred to as the correlation value r. The closer the correlation value r is to 1.0, the higher the correlation between the reference source imaging region 1401 and the reference destination non-imaging region 1403, and the farther away from 1.0, the higher the correlation between the reference source imaging region 1401 and the reference destination non-imaging region 1401. It shows that the correlation with the region 1403 is low.

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

The correlation value r is close to 1.0 when the reference destination non-imaging region 1403 includes the reference source imaging region 1401. For example, in FIG. 26, when the reference source imaging region 1401 is the imaging region 600-11 and the reference non-imaging region 1403 is the non-imaging region 610-11, the reference non-imaging region 1403 is the non-imaging region 610-12. Compared with the case of, the correlation value r is closer to 1.0. This is because when the reference destination non-imaging region 1403 includes the reference source imaging region 1401, the reference destination non-imaging region 1403 is read by the same column readout line.

The correlation value r is close to 1.0 if the reference source imaging region 1401 and the reference destination non-imaging region 1403 are in the same row. For example, in FIG. 26, when the reference source imaging region 1401 is the imaging region 600-11 and the reference non-imaging region 1403 is the non-imaging region 610-11, the reference non-imaging region 1403 is the non-imaging region 610-22. Compared with the case of, the correlation value r is closer to 1.0. This is because if the rows are the same, they are read by the column reading line at the same timing.

Further, the correlation value r becomes closer to 1.0 as the reference source imaging region 1401 and the reference destination non-imaging region 1403 are closer to each other. For example, in FIG. 26, when the reference source imaging region 1401 is the imaging region 600-11, the reference non-imaging region 1403 is the non-imaging region 610-12, and the reference source imaging region 1401 is the imaging region 600-14. The correlation value r is close to 1.0. This is because it is considered that the closer the pixel positions are, the more similar their characteristics are.

The present invention is not limited to the above contents, and may be any combination thereof. In addition, other aspects considered within the scope of the technical idea of the present invention are also included in the scope of the present invention.

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

Claims

A second direction that includes a first photoelectric conversion unit that receives light from an optical system and converts it into electric charges and a first circuit unit that is connected to the first photoelectric conversion unit, and intersects the first direction and the first direction. A first imaging region having a plurality of first pixels arranged in and a first control line connected to the plurality of first pixels and a signal for controlling the plurality of first pixels is output.
It includes a second photoelectric conversion unit that receives light from an optical system and converts it into electric charges, and a second circuit unit that is connected to the second photoelectric conversion unit, and is arranged in the first direction and the second direction. A second imaging region having a plurality of second pixels and a second control line connected to the plurality of second pixels and outputting a signal for controlling the plurality of second pixels.
It has a third pixel including a light-shielded third photoelectric conversion unit and a third circuit unit connected to the third photoelectric conversion unit.
The first imaging region is specified so as to include all the first pixels of the first imaging region connected to the first control line and to have the shortest outer edge. Having the third pixel inside the closed area,
The second imaging region is specified so as to include all the second pixels of the second imaging region connected to the second control line and to have the shortest outer edge. An image sensor that does not have the third pixel inside the closed region.
The image pickup device according to claim 1.
A plurality of fourth pixels arranged in the first direction and the second direction, including a light-shielded fourth photoelectric conversion unit and a fourth circuit unit connected to the fourth photoelectric conversion unit, and the plurality of pixels. A fourth control line connected to the fourth pixel of the above and output a signal for controlling the fourth pixel, and a light-shielding pixel region having the fourth control line.
The light-shielding pixel region is an image pickup device arranged outside the first image pickup region and the second image pickup region.
The image pickup device according to claim 1 or 2.
The number of the first image pickup regions is smaller than the number of the second image pickup regions.
The image pickup device according to any one of claims 1 to 3.
The first image pickup region is an image pickup device arranged at a position closer to the edge of the image pickup pixel region than the second image pickup region in the image pickup pixel region including the first image pickup region and the second image pickup region. ..
The image pickup device according to any one of claims 1 to 3.
The third pixel is an image pickup device provided in the first image pickup region in which the number of image plane phase difference detection pixels is a predetermined number or less.
The image pickup device according to any one of claims 1 to 3.
The third pixel is an image pickup device provided in the first image pickup region in which there are fewer image plane phase difference detection pixels than the second image pickup region.
The image pickup device according to claim 3.
An image pickup device in which the second image pickup region and the light-shielding pixel region are arranged in a predetermined direction.
The image pickup device according to claim 7.
The image pickup device, in which the predetermined direction is the reading direction of output signals from the pixel groups constituting the second image pickup region and the light-shielding pixel region.
The image pickup device according to claim 7.
An image pickup device whose predetermined direction is orthogonal to the reading direction of output signals from the pixel groups constituting the second image pickup region and the light-shielding pixel region.
It has a plurality of imaging regions composed of a group of pixels for imaging a subject, imaging conditions are set for each of the plurality of imaging regions, and two or more types of imaging conditions are set for the plurality of imaging regions. Effective pixel area and
The effective pixel region is composed of a first optical black pixel group, has a plurality of first non-imaging regions smaller than the imaging region, and each of the plurality of first non-imaging regions is a reference source imaging region. The first optical black pixel region in which the same or different imaging conditions are set, and
An image sensor having.
The image pickup device according to claim 10.
The first optical black pixel group is an image pickup device having an optical black pixel group each having a photoelectric conversion element and an optical black pixel group each having no photoelectric conversion element.
The image pickup device according to claim 10 or 11.
The first non-imaging region is an image pickup device having an optical black pixel group each having a photoelectric conversion element and an optical black pixel group each having no photoelectric conversion element.
The image sensor according to any one of claims 10 to 12, and the image sensor.
Output from the reference source imaging region based on the correlation between the placement position of the reference source imaging region and the placement position of the reference destination first non-imaging region referred to by the reference source imaging region. A signal processing unit that corrects the signal using the output signal from the first non-imaging region of the reference destination, and
An imaging device having.
The imaging device according to claim 13.
Based on the difference between the imaging conditions of the imaging region of the reference source and the imaging conditions of the first non-imaging region of the reference destination, the signal processing unit outputs the output signal from the imaging region of the reference source. An imaging device that corrects using the output signal from the referenced non-imaging area.
The imaging apparatus according to claim 13 or 14.
The first non-imaging region of the reference destination includes a third imaging region and a fourth imaging region closer to the first non-imaging region of the reference destination than the third imaging region as the imaging region of the reference source. Referenced
The signal processing unit is based on a correlation stronger than the correlation between the arrangement position of the third imaging region of the reference source and the arrangement position of the first non-imaging region of the reference destination. An imaging device that corrects the output signal from the fourth imaging region by using the output signal from the first non-imaging region of the reference destination.
The imaging apparatus according to any one of claims 13 to 15.
The signal processing unit is based on the correlation between the arrangement position of the imaging region of the reference source and the arrangement position of the second non-imaging region of the reference destination referred to by the imaging region of the reference source. An imaging device that corrects the output signal from the imaging region of the above using the output signal from the second non-imaging region of the reference destination.
The imaging apparatus according to claim 14.
Based on the difference between the imaging conditions of the imaging region of the reference source and the imaging conditions of the second non-imaging region of the reference destination, the signal processing unit outputs the output signal from the imaging region of the reference source. An imaging device that corrects using the output signal from the referenced second non-imaging region.
The imaging apparatus according to claim 16 or 17.
The second non-imaging region of the reference destination is referred to as an imaging region of the reference source by a third imaging region and a fourth imaging region closer to the non-imaging region of the reference destination than the third imaging region.
The signal processing unit is based on a correlation stronger than the correlation between the arrangement position of the third imaging region of the reference source and the arrangement position of the second non-imaging region of the reference destination. An imaging device that corrects the output signal from the fourth imaging region by using the output signal from the second non-imaging region of the reference destination.