Photoelectric converter

Abstract

To provide a photoelectric conversion device that can improve the quality of the output image. [Solution] The system comprises a pixel array, a first output line, a second output line, and a correction value generation unit. The pixel array includes a first region and a second region, and each row of the first and second regions includes an effective pixel region and a correction signal acquisition region. The first output line is connected to a pixel in the first region but not to a pixel in the second region. The second output line is connected to a pixel in the second region but not to a pixel in the first region. The second region includes a first pixel row and a second pixel row adjacent to the first region. The correction value generation unit generates a correction value used for black level correction of the signal output from the pixels of the first pixel row based on a first correction coefficient and a correction signal, and generates a correction value used for black level correction of the signal output from the pixels of the second pixel row based on a second correction coefficient different from the first correction coefficient and the correction signal.

Description

Technical Field

[0006] , ,

[0001] The present invention relates to a photoelectric conversion device.

Background Art

[0002] Patent Document 1 discloses an image pickup device having a plurality of pixel circuits arranged in a plurality of rows and a plurality of columns, and a plurality of signal lines from which signals are read out from the pixel circuits. In the image pickup device of Patent Document 1, the region where the plurality of pixel circuits are arranged is divided into a first pixel region and a second pixel region. And in one column, the pixels arranged in the first pixel region and the pixels arranged in the second pixel region are connected to different signal lines. Thereby, parasitic resistance and parasitic capacitance are reduced, and the settling time is shortened, so that the reading speed can be increased.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a photoelectric conversion device in which reading is performed by different output lines for each region as in Patent Document 1, a difference may occur in the level of the output signal near the boundary of the region. As a result, the quality of the output image may be reduced.

[0005] An object of the present invention is to provide a photoelectric conversion device capable of improving the quality of an output image.

Means for Solving the Problems

[0006] According to one disclosure of this specification, a pixel array includes a plurality of pixels arranged in a plurality of rows and a plurality of columns, a first output line and a second output line, each arranged to correspond to one of the plurality of columns, and a correction value generation unit that generates a correction value used for black level correction of the signal output from the pixel array, wherein the pixel array includes a first region including a continuous portion of the plurality of rows, and a second region adjacent to the first region including another continuous portion of the plurality of rows, and each row of the first region and the second region includes an effective pixel region that outputs a signal corresponding to incident light by photoelectric conversion and a correction signal acquisition region that outputs a correction signal, A photoelectric converter is provided, characterized in that a first output line is connected to a pixel in the first region and not to a pixel in the second region, a second output line is connected to a pixel in the second region and not to a pixel in the first region, the second region includes a first row of pixels and a second row of pixels adjacent to the first region, and the correction value generation unit generates a correction value used for black level correction of the signal output from the pixels of the first row of pixels based on a first correction coefficient and the correction signal, and generates a correction value used for black level correction of the signal output from the pixels of the second row of pixels based on a second correction coefficient different from the first correction coefficient and the correction signal. [Effects of the Invention]

[0007] According to the present invention, a photoelectric conversion device is provided in which the quality of the output image is improved. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram showing an example configuration of a photoelectric conversion device according to the first embodiment. [Figure 2] This is a perspective view showing an example configuration of a photoelectric conversion device according to the first embodiment. [Figure 3] This is a schematic diagram showing an example of the configuration of a pixel array according to the first embodiment. [Figure 4] This is a circuit diagram showing an example of the pixel configuration according to the first embodiment. [Figure 5]This diagram schematically shows the signal levels of each row before correction. [Figure 6] This diagram schematically shows the signal levels of each row after correction. [Figure 7] This diagram schematically shows the signal levels of each row before correction when step-like noise occurs due to output line splitting. [Figure 8] This is a block diagram of the signal processing unit according to the first embodiment. [Figure 9] This is a block diagram of the correction value generation unit according to the first embodiment. [Figure 10] This is a flowchart showing the black level correction method according to the first embodiment. [Figure 11] This diagram schematically shows the signal level of each row before correction and the correction coefficient switching signal according to the first embodiment. [Figure 12] This figure schematically shows the signal levels of each row after correction according to the first embodiment. [Figure 13] This is a block diagram of the correction value generation unit according to the second embodiment. [Figure 14] This is a flowchart showing the black level correction method according to the second embodiment. [Figure 15] This figure schematically shows the signal level of each row before correction and the correction coefficient switching signal according to the second embodiment. [Figure 16] This is a block diagram showing an example configuration of a photoelectric converter according to the third embodiment. [Figure 17] This diagram schematically shows the signal levels of each row before correction and the correction coefficient switching signals according to the third embodiment. [Figure 18] This figure shows an example configuration of the imaging system according to the fourth embodiment. [Figure 19] This is a block diagram showing the schematic configuration of the equipment according to the fifth embodiment. [Figure 20] This is a block diagram showing the schematic configuration of the device according to the sixth embodiment. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described while referring to the drawings. The same elements or corresponding elements throughout the plurality of drawings are denoted by common reference numerals, and the description thereof may be omitted or simplified.

[0010] [First Embodiment] FIG. 1 is a block diagram showing a configuration example of a photoelectric conversion device 1 according to the present embodiment. The photoelectric conversion device 1 includes a pixel array 11, a control unit 12, a vertical scanning unit 13, a readout circuit unit 14, an AD conversion unit (analog-digital conversion unit) 15, a memory unit 16, a horizontal scanning unit 17, and a signal processing unit 18.

[0011] The pixel array 11 has a plurality of pixels P arranged in a plurality of rows and a plurality of columns. The pixel P may include a photoelectric conversion element. In FIG. 1, the pixels P arranged in a 2m-column × 2n-row matrix are shown as rectangular blocks. In FIG. 1, coordinates represented by (column number, row number) are appended to the reference numerals of the pixels. In this specification, the direction in which each row extends (row direction) is defined as the horizontal direction, and the direction in which each column extends (column direction) is defined as the vertical direction. Also, the row number of the uppermost row is the first row, and the column number of the leftmost column is the first column.

[0012] The vertical scanning unit 13 is a control circuit (pixel control unit) that operates in response to a control signal from the control unit 12 and drives the pixels P constituting the pixel array 11 in units of rows. The vertical scanning unit 13 supplies a control signal to the pixels P in units of rows via control lines V(1) to V(2n) arranged for each row of the pixel array 11. The vertical scanning unit 13 may be configured using a shift register or an address decoder. Each of the control lines V(1) to V(2n) may be constituted by a plurality of signal lines. In the notation of the control line V, the numerical value in parentheses indicates the row number.

[0013] The photoelectric converter 1 has vertical output lines Ha(1) to Ha(2m) arranged to correspond to the first column to the second m column, respectively, and vertical output lines Hb(1) to Hb(2m) arranged to correspond to the first column to the second m column, respectively. Each of the vertical output lines Ha(1) to Ha(2m) (first output line) is connected to the pixel P of the corresponding column in region R1 (first region) from the first row to the nth row. Each of the vertical output lines Hb(1) to Hb(2m) (second output line) is connected to the pixel P of the corresponding column in region R2 (second region) from the (n+1)th row to the 2nth row. In other words, in this embodiment, two vertical output lines are arranged to correspond to a pixel P of one column. In the notation of vertical output lines Ha and Hb, the numbers in parentheses indicate the column number. Regions R1 and R2 each contain multiple consecutive rows. In the example in Figure 1, the number of rows in regions R1 and R2 are the same, but they may be different.

[0014] The vertical scanning unit 13 is connected to 2m pixels P arranged in corresponding rows via control lines V(1) to V(2n) and selects rows to be reset or rows to read signals. Pixel P selected as rows to be reset are reset and exposure begins. Pixel P of rows selected as rows to read signals simultaneously output signals to the readout circuit unit 14 via the corresponding vertical output lines Ha(1) to Ha(2m) or Hb(1) to Hb(2m). In these reset and signal readout operations, the vertical scanning unit 13 sequentially selects control lines V(1) to V(2n). That is, the vertical scanning unit 13 controls scanning multiple pixels P so that multiple pixels P sequentially output signals row by row.

[0015] The readout circuit 14 is a circuit that reads analog signals from the pixels P of each row. The readout circuit 14 may also include an amplification circuit that amplifies the signals output from the pixels P. The readout circuit 14 may also include a switch to switch between vertical output lines from which signals are read. For example, the readout circuit 14 may be able to switch between reading signals from vertical output lines Ha(1) to Ha(2m) and reading signals from vertical output lines Hb(1) to Hb(2m).

[0016] The AD conversion unit 15 converts the analog signal output from the read circuit unit 14 into a digital signal. The memory unit 16 temporarily holds the digital signal output from the AD conversion unit 15. The AD conversion and digital signal holding may be performed column by column. That is, the AD conversion unit 15 may include an AD conversion circuit corresponding to each column. The memory unit 16 may include a memory corresponding to each column.

[0017] The horizontal scanning unit 17 operates in response to a control signal from the control unit 12 and is a circuit that sequentially transfers the digital signals held in the memory of each column of the memory unit 16 to the signal processing unit 18, column by column. The horizontal scanning unit 17 may be configured using a shift register or an address decoder. The digital signals at the addresses specified by the horizontal scanning unit 17 are sequentially read from the memory unit 16 to the signal processing unit 18.

[0018] The signal processing unit 18 is a signal processing circuit that performs various digital signal processing to reduce noise generated in the pixel array 11, readout circuit unit 14, AD conversion unit 15, memory unit 16, horizontal scanning unit 17, etc. The signal processing unit 18 outputs the processed signal to the outside of the photoelectric converter 1 in a predetermined format.

[0019] The control unit 12 is a control circuit that acquires signals indicating setting information such as the shooting conditions when the photoelectric converter 1 performs imaging, and generates control signals based on the setting information. The control unit 12 controls the vertical scanning unit 13, the readout circuit unit 14, the AD conversion unit 15, the memory unit 16, the horizontal scanning unit 17, and the signal processing unit 18 by outputting control signals to these units.

[0020] The photoelectric converter 1 according to this embodiment may be formed on a single substrate, or it may be a stacked type in which multiple substrates are stacked. Figure 2 is a perspective view showing an example of the configuration of a stacked type photoelectric converter 1. As shown in Figure 2, the photoelectric converter 1 may be a stacked type photoelectric converter in which a pixel substrate 10a and a circuit board 10b are stacked and electrically connected. The pixel substrate 10a and the circuit board 10b may be semiconductor substrates such as silicon.

[0021] The pixel substrate 10a (first substrate) may contain the pixel array 11, which is a component of the photoelectric converter 1. At least a portion of the wiring that constitutes the vertical output lines Ha(1) to Ha(2m) and Hb(1) to Hb(2m) is provided on the pixel substrate 10a. The circuit board 10b (second substrate) may contain the control unit 12, vertical scanning unit 13, readout circuit unit 14, AD conversion unit 15, memory unit 16, horizontal scanning unit 17, and signal processing unit 18, which are components of the photoelectric converter 1. The vertical output lines Ha(1) to Ha(2m) and Hb(1) to Hb(2m) are electrically connected to the readout circuit unit 14.

[0022] By configuring the photoelectric converter 1 in this way, it becomes possible to select an appropriate manufacturing process for the analog section including the pixel array 11 and the logic section including the signal processing unit 18 when manufacturing the photoelectric converter 1. This improves the characteristics of each part of the photoelectric converter 1. Therefore, it is possible to realize a photoelectric converter 1 with improved image quality.

[0023] As described above, the photoelectric converter 1 includes a pixel array 11 and a signal processing unit 18, but is not limited to this. The signal processing unit 18 may be located in a separate signal processing unit from the pixel array 11. Furthermore, the signal processing unit 18 may be located in an external signal processing unit to the photoelectric converter 1. In this case, the signal processing unit corrects the signals output from the photoelectric converter 1 to generate image data, etc. The signal processing unit 18 may also be implemented by a computer including a processor (CPU (Central Processing Unit), MPU (Micro Processing Unit), etc.). Additionally, the signal processing unit 18 may be implemented by a circuit such as an ASIC (Application Specific Integrated Circuit).

[0024] Figure 3 is a schematic diagram showing an example configuration of a pixel array 11 according to this embodiment. The pixel array 11 includes an effective pixel region 11a and correction signal acquisition regions 11b and 11c. The effective pixel region 11a is a region in which effective pixels, including photoelectric conversion elements, are arranged. The effective pixels output signals corresponding to the light incident on the pixel array 11 after passing through an optical system such as a lens. The correction signal acquisition region 11b is a region in which correction pixels, which output correction signals used for black level correction, are arranged. The correction signal acquisition regions 11b and 11c may be light-shielding regions in which the light incident on the photoelectric conversion elements is optically shielded, for example, by placing a light-shielding portion such as a light-shielding film on the photoelectric conversion elements. Such light-shielding regions may also be called optical black (OB) regions.

[0025] The correction signal acquisition area 11c is located to the left of the effective pixel area 11a, corresponding to each row of the effective pixel area 11a. The correction signal acquisition area 11c is sometimes called the HOB area. The correction signal acquisition area 11c may also be located to the right of the effective pixel area 11a.

[0026] The correction signal acquisition area 11b is located above the effective pixel area 11a and the correction signal acquisition area 11c. The correction signal acquisition area 11b is sometimes called the VOB area. The correction signal acquisition area 11b may also be located below the effective pixel area 11a and the correction signal acquisition area 11c.

[0027] Furthermore, the correction signal acquisition regions 11b and 11c are not limited to the OB region where the photoelectric conversion element is shielded from light. For example, the correction signal acquisition regions 11b and 11c may be dummy regions that do not have a photoelectric conversion element. The pixels P in the dummy region have a configuration similar to that of the effective pixels in the effective pixel region 11a, with the photoelectric conversion element removed. In this case, the correction signal acquisition region 11c may be called a horizontal dummy region, and the correction signal acquisition region 11b may be called a vertical dummy region. Also, the correction signal acquisition regions 11b and 11c may include both the OB region and the dummy region.

[0028] Figure 4 is a circuit diagram showing an example of the configuration of a pixel P according to the first embodiment. Figure 4 illustrates a pixel P(m,n) located in the mth row and nth column of the pixel array 11, but other pixels P have a similar configuration. Pixel P includes a photoelectric conversion element PD, a transfer transistor M1, a reset transistor M2, an amplification transistor M3, and a selection transistor M4.

[0029] A photoelectric conversion element (PD) is a device that generates and stores an electric charge corresponding to the incident light by converting the incident light into electricity. A photoelectric conversion element (PD) is, for example, a photodiode. Here, we assume that the photoelectric conversion element (PD) is composed of photodiodes.

[0030] The anode of the photodiode constituting the photoelectric conversion element PD is connected to the ground node. The cathode of the photodiode constituting the photoelectric conversion element PD is connected to the source of the transfer transistor M1. The drain of the transfer transistor M1 is connected to the source of the reset transistor M2 and the gate of the amplification transistor M3. The connection node between the drain of the transfer transistor M1, the source of the reset transistor M2, and the gate of the amplification transistor M3 is the so-called floating diffusion section FD.

[0031] The drains of reset transistor M2 and amplifier transistor M3 are connected to the power supply voltage node (voltage VCC). The source of amplifier transistor M3 is connected to the drain of selection transistor M4. The source of selection transistor M4 is connected to the vertical output line Ha(m).

[0032] In the pixel configuration shown in Figure 4, each control line in each row of the pixel array 11 includes a transfer gate signal line, a reset signal line, and a selection signal line. The transfer gate signal line of the nth row is connected to the gate of the transfer transistor M1 from pixels P(1,n) to P(2m,n) in the nth row. The transfer gate signal line of the nth row supplies the control signal PTX(n) output from the vertical scanning unit 13 to the gate of the transfer transistor M1 from pixels P(1,n) to P(2m,n).

[0033] The reset signal line for the nth row is connected to the gate of the reset transistor M2 for pixels P(1,n) to P(2m,n) in the nth row. The reset signal line for the nth row supplies the control signal PRES(n) output from the vertical scanning unit 13 to the gate of the reset transistor M2 for pixels P(1,n) to P(2m,n).

[0034] The selection signal line for the nth row is connected to the gate of the selection transistor M4 for pixels P(1,n) through P(2m,n) in the nth row. The selection signal line for the nth row supplies the control signal PSEL(n) output from the vertical scanning unit 13 to the gate of the selection transistor M4 for pixels P(1,n) through P(2m,n). In this way, a common control signal is supplied from the vertical scanning unit 13 to pixels P in the same row.

[0035] When each transistor is composed of an N-channel transistor, a high-level control signal supplied from the vertical scanning unit 13 causes the corresponding transistor to conduct. Conversely, a low-level control signal supplied from the vertical scanning unit 13 causes the corresponding transistor to deconduct. Note that each transistor constituting the pixel P may be composed of an N-channel transistor, but may also be composed of a P-channel transistor.

[0036] The photoelectric conversion element PD converts incident light into an amount of charge corresponding to the amount of light (photoelectric conversion) and stores the generated charge. When the transfer transistor M1 turns on (conducts), it transfers the charge held by the photoelectric conversion element PD to the floating diffusion section FD. The floating diffusion section FD contains a capacitive component and holds the charge transferred from the photoelectric conversion element PD in its capacitance, and the charge voltage conversion by its capacitance results in a potential corresponding to the amount of charge.

[0037] A bias current is supplied to the source of the amplification transistor M3 from a current source (not shown) via the vertical output line Ha(m) and the selection transistor M4. The power supply voltage (voltage VCC) is supplied to the drain of the amplification transistor M3. In other words, the amplification transistor M3 constitutes a source follower circuit with its gate as the input node. As a result, the amplification transistor M3 outputs a signal based on the potential of the floating diffusion section FD to the vertical output line Ha(m) via the selection transistor M4.

[0038] The reset transistor M2 resets the floating diffusion section FD to a potential corresponding to the power supply voltage (voltage VCC) when it is turned on (conducting). By turning on the transfer transistor M1 (conducting) at the same time as the reset transistor M2, the photoelectric conversion element PD can also be reset to a potential corresponding to voltage VCC. The selection transistor M4 switches the connection between the amplification transistor M3 and the vertical output line Ha(m).

[0039] The photoelectric conversion element PD is reset to a potential corresponding to the power supply voltage (voltage VCC) by turning on the transfer transistor M1 and the reset transistor M2. By turning off the transfer transistor M1 from this reset state, the reset state of the photoelectric conversion element PD is released, and exposure (charge accumulation) in the photoelectric conversion element PD begins.

[0040] The readout operation of pixel P involves reading out the noise signal (N signal) and the signal based on incident light (S signal). The N signal is read out by releasing the reset state of the floating diffuser FD, and then outputting a signal corresponding to the potential of the reset floating diffuser FD to the vertical output line Ha(m) using the amplification transistor M3. The reset state of the floating diffuser FD is released by turning off the reset transistor M2.

[0041] The S signal is read out by transferring the charge held by the photoelectric conversion element PD to the floating diffusion section FD after the N signal has been read out, and then outputting a signal corresponding to the amount of charge transferred to the floating diffusion section FD to the vertical output line Ha(m).

[0042] By applying correlated double sampling (SN) to the S and N signals read out in this manner, pixel signals with reduced reset noise from the floating diffusion unit FD can be obtained. The signal processing unit 18 can reduce reset noise by performing correlated double sampling or the like.

[0043] As described above, the signal read out may contain fixed pattern noise. Fixed pattern noise can be caused by variations in dark current generated in the photoelectric conversion element PD, power supply impedance in the circuit constituting the photoelectric conversion device 1, signal delay, etc. Furthermore, the fixed pattern noise may change according to a predetermined regularity depending on the row or column, and such a state is called shading.

[0044] The signal processing unit 18 performs a process to reduce reset noise, and then generates a correction value for correcting fixed pattern noise by averaging multiple correction signals acquired from predetermined areas within the correction signal acquisition areas 11b and 11c row by row or column by column. The signal processing unit 18 then performs a correction process to reduce the fixed pattern noise using the correction value.

[0045] Figures 5(a) and 5(b) schematically show the signal levels of each row before correction. In Figures 5(a) and 5(b), the vertical axis indicates the row position of the pixel P from which the signal was output, and the horizontal axis indicates the signal level. Figure 5(a) shows the distribution of signal levels of the output signals from pixel P on the A-A' line in Figure 3, and Figure 5(b) shows the distribution of signal levels of the output signals from pixel P on the B-B' line in Figure 3. In Figures 5(a) and 5(b), the hatched boxes indicate the output signals of the correction signal acquisition regions 11b and 11c, and the unhatched boxes indicate the output signals of the effective pixel region 11a. Furthermore, row V1 shown in Figures 5(a) and 5(b) is the bottom row of the correction signal acquisition region 11b, and row V2 shown in Figures 5(a) and 5(b) is the top row of the effective pixel region 11a.

[0046] As shown in Figure 5(a), in this example, shading occurs such that the signal level is higher in rows with larger row numbers, i.e., lower rows. The reference signal level L1 in Figure 5(a) is the reference value for the black level. The difference between the correction value level C1 and the reference signal level L1 corresponds to the shading component that is reduced in the fixed pattern noise correction process. In Figure 5(b), there is a difference in signal level between row V1 in the correction signal acquisition area 11b and row V2 in the effective pixel area 11a. This level difference indicates the signal component due to incident light.

[0047] In the following explanations, diagrams illustrating the signal levels of each row, similar to those in Figures 5(a) and 5(b), may be used. In such cases, redundant explanations will be omitted or simplified as appropriate.

[0048] Figures 6(a) and 6(b) schematically show the signal levels of each row after correction of fixed pattern noise. In this correction, the difference between the correction value level C1 and the reference signal level L1 is subtracted from the output signal. Figure 6(a) shows the distribution of corrected signal levels of the output signal from pixel P on the A-A' line in Figure 3. As shown in Figure 6(a), the shading component is removed, and the signal levels of each row are uniform. Figure 6(b) shows the distribution of corrected signal levels of the output signal from pixel P on the B-B' line in Figure 3. As shown in Figure 6(b), the shading component is removed, and the signal levels are uniform in both the correction signal acquisition region 11b and the effective pixel region 11a. The signal level L2 in Figure 6(b) represents the signal component due to incident light.

[0049] Here, the correction value level C1 can be obtained, for example, by integral averaging the output signals of the correction signal acquisition region 11b row by row. However, the output signals of the correction signal acquisition region 11b may contain different random noise for each pixel P. Therefore, if the process of integral averaging the output signals of the correction signal acquisition region 11b row by row is adopted, the correction accuracy may decrease due to variations in the integral average value caused by random noise. To reduce the effect of random noise, the output signals of the correction signal acquisition region 11b may be processed with a digital low-pass filter. This may improve the correction accuracy. An example of a digital low-pass filter is an IIR (Infinite Impulse Response) filter.

[0050] In this embodiment, two vertical output lines, Ha and Hb, are arranged so that each pixel P in a single row corresponds to one of them. Due to the different signal transmission paths, a characteristic difference in the output signal may occur between pixels P whose signal is read out on vertical output line Ha and pixels P whose signal is read out on vertical output line Hb. This characteristic difference can cause a step in the signal level at the boundary between region R1 where pixels P whose signal is read out on vertical output line Ha are located and region R2 where pixels P whose signal is read out on vertical output line Hb are located. This step appears as a line near the center of the image and is therefore easily visible to the viewer. In the configuration of this embodiment, the output line division step caused by such factors can be a cause of image quality degradation. Figures 5(a), 5(b), 6(a), and 6(b) illustrate cases where no output line division step occurs or where its effect is negligibly small, but there are also cases where the effect of the output line division step is not negligible. Furthermore, even if correction is performed using signal processing with low-pass filters such as IIR filters as described above, the correction for output line splitting steps may be insufficient.

[0051] Figures 7(a) and 7(b) schematically show the signal levels of each row before correction when step-like noise occurs due to output line splitting. In Figures 7(a) and 7(b), row V3 is the lowest row of region R1 where the signal is read out on vertical output line Ha, and row V4 is the highest row of region R2 where the signal is read out on vertical output line Hb. As shown in Figures 7(a) and 7(b), there is a difference in signal level between row V3 and row V4. This level difference indicates an output line splitting step caused by the switching of vertical output lines Ha and Hb from which the signal is read out. The correction value level C2 generated by an IIR filter, etc., using the output signal shown in Figure 7(a) does not follow the output line splitting step. Therefore, in the example of Figures 7(a) and 7(b), the correction for the output line splitting step may be insufficient.

[0052] The following describes an example configuration and correction method for a signal processing unit 18 that can appropriately correct even when output line splitting steps may occur. Figure 8 is a block diagram of the signal processing unit 18 according to this embodiment. The signal processing unit 18 has a processing circuit 180. The processing circuit 180 has a correction unit 181 and a correction value generation unit 182.

[0053] The correction value generation unit 182 generates a correction value used for black level correction based on the correction signals acquired in the correction signal acquisition areas 11b and 11c and the correction coefficient switching signal. The correction unit 181 performs black level correction of the pixel signal by subtracting the correction value from the pixel signal acquired in the effective pixel area 11a.

[0054] Figure 9 is a block diagram of the correction value generation unit 182 according to this embodiment. The correction value generation unit 182 includes a row average value calculation unit 182a, a subtraction unit 182b, a correction coefficient selection unit 182c, an attenuation unit 182d, an addition unit 182e, and a correction value holding unit 182f.

[0055] The correction value generation unit 182 performs filtering by referring to three things: the row average value of the correction signal calculated by the row average value calculation unit 182a, the attenuation coefficient set by the attenuation unit 182d, and the correction value held in the correction value holding unit 182f. This filtering process generates a new correction value. In this embodiment, the processing performed by the correction value generation unit 182 is the process of applying a digital low-pass filter to the correction signal row by row to generate a correction value. In the example in Figure 9, the digital low-pass filter is an IIR filter.

[0056] For the filtering process described above, it is desirable to use an IIR filter from the viewpoint of reducing row variability. However, the processing of the correction value generation unit 182 is not limited to processing using an IIR filter. For example, integral averaging may be used in the processing of the correction value generation unit 182.

[0057] The row average value calculation unit 182a calculates the row average value of the correction signals acquired in the correction signal acquisition areas 11b and 11c. It is preferable that the correction signals used to calculate the row average value are acquired from the correction signal acquisition area 11c. This is because the correction signals for the same rows as those in the effective pixel area 11a can be acquired from the correction signal acquisition area 11c, making it possible to effectively correct noise that depends on the position of the pixel row.

[0058] The row average value calculated by the row average value calculation unit 182a is input to the subtraction unit 182b. The subtraction unit 182b subtracts the correction value held in the correction value holding unit 182f from the row average value and outputs it to the attenuation unit 182d.

[0059] The correction coefficient selection unit 182c receives a correction coefficient switching signal, correction coefficients K0 and K1 as inputs. These control signals may be input from, for example, the control unit 12, the vertical scanning unit 13, other blocks of the photoelectric converter 1, or from outside the photoelectric converter 1. The correction coefficient switching signal is a signal for transmitting the timing for switching the correction coefficient to the correction coefficient selection unit 182c. This timing corresponds to the readout timing near the boundary between the region where pixels P whose signals are read out on the vertical output line Ha are located and the region where pixels P whose signals are read out on the vertical output line Hb are located. The correction coefficients K0 and K1 are attenuation coefficients of the attenuation processing performed in the attenuation unit 182d. Correction coefficients K0 and K1 are different values ​​from each other.

[0060] The correction coefficient selection unit 182c selects either correction coefficient K0 or correction coefficient K1 based on the correction coefficient switching signal and outputs it to the attenuation unit 182d. The correction coefficient selection unit 182c selects correction coefficient K0 (first correction coefficient) when the correction coefficient switching signal is "0", and selects correction coefficient K1 (second correction coefficient) when the correction coefficient switching signal is "1". The attenuation unit 182d attenuates the signal output from the subtraction unit 182b (the value obtained by subtracting the correction value from the row average value) according to the correction coefficient selected by the correction coefficient selection unit 182c.

[0061] The attenuated signal output from the attenuation unit 182d is input to the adder unit 182e. The adder unit 182e adds the output signal from the attenuation unit 182d to the correction value held in the correction value holding unit 182f. The newly obtained correction value is output from the correction value generation unit 182 to the correction unit 181. This correction value is also held in the correction value holding unit 182f and used to generate the correction value for the next row.

[0062] To summarize the above process, the IIR filter processing performed by a loop including a subtraction unit 182b, an attenuation unit 182d, an addition unit 182e, and a correction value holding unit 182f can be expressed by the following equation (1). Correction value for row k = Attenuation coefficient × Row mean value for row k + (1 - Attenuation coefficient) × Correction value for row (k-1) (1) Here, the "damping coefficient" in equation (1) is the damping coefficient of the damping section 182d determined by the correction coefficient K0 or the correction coefficient K1, and is a value greater than 0 and less than or equal to 1.

[0063] In the situations shown in Figures 7(a) and 7(b), the correction coefficient switching signal is set to "1" immediately after the vertical output lines Ha and Hb from which the signals are read out switch, i.e., at the timing of the readout of row V4 (second pixel row). At this time, the correction coefficient K1 is selected. On the other hand, at the timing of the readout of each row in region R1, i.e., each row up to row V3 (third pixel row), the correction coefficient switching signal is set to "0". At this time, the correction coefficient K0 is selected. At the timing of the readout of each row other than row V4 (first pixel row) in region R2, the correction coefficient switching signal is also set to "0". At this time, the correction coefficient K0 is selected.

[0064] It is desirable that the attenuation coefficient of the attenuation section 182d set by the correction coefficient K1 be smaller than the attenuation coefficient of the attenuation section 182d set by the correction coefficient K0. This setting allows for higher tracking performance of the IIR filter when the correction coefficient K1 is set compared to when the correction coefficient K0 is set. As a result, the correction coefficient switches at the timing when the vertical output lines Ha and Hb from which the signal is read out switch, enabling the generation of a correction value with high tracking performance. Therefore, since the tracking performance of the correction is higher at the timing when the vertical output lines Ha and Hb from which the signal is read out switch, the output line division step can be corrected more effectively.

[0065] Figure 10 is a flowchart showing the black level correction method according to this embodiment. An example of the processing procedure in the signal processing unit 18 will be described. Parts that overlap with the explanations in Figures 8 and 9 may be omitted or simplified as appropriate.

[0066] In step S11, the photoelectric converter 1 acquires a correction signal from the correction signal acquisition area 11c of the pixel array 11. This correction signal is input to the row average value calculation unit 182a.

[0067] In step S12, the row average value calculation unit 182a calculates the row average value from the correction signal.

[0068] In step S13, the correction coefficient selection unit 182c determines whether the value of the input correction coefficient switching signal is "1". If the correction coefficient switching signal is "1" in step S13 (YES in step S13), the process proceeds to step S14. In step S14, the correction coefficient selection unit 182c selects the correction coefficient K1 and outputs it to the attenuation unit 182d. The process then proceeds to step S16.

[0069] In step S13, if the correction coefficient switching signal is not "1" (NO in step S13), the process proceeds to step S15. In step S15, the correction coefficient selection unit 182c selects the correction coefficient K0 and outputs it to the attenuation unit 182d. After that, the process proceeds to step S16.

[0070] In step S16, the subtraction unit 182b, the attenuation unit 182d, the addition unit 182e, and the correction value holding unit 182f generate a correction value using the IIR filter described above. The generated correction value is held in the correction value holding unit 182f. This updates the correction value held in the correction value holding unit 182f. This correction value is also output to the correction unit 181.

[0071] In step S17, the correction unit 181 performs black level correction of the pixel signal by subtracting the updated correction value from the pixel signal acquired in the effective pixel area 11a.

[0072] Figures 11(a) and 11(b) schematically show the signal level and correction coefficient switching signal of each row before correction according to this embodiment. Figures 11(a) and 11(b) show the changes in the correction value level C3 and the correction coefficient switching signal when the processing shown in Figures 8 to 10 is applied in the case where step noise occurs due to output line splitting, similar to Figures 7(a) and 7(b). Row V5 (first pixel row) shown in Figures 11(a) and 11(b) is the row following row V4. That is, row V5 is the second row in the region where the signal is read out to the vertical output line Hb.

[0073] As shown in Figures 11(a) and 11(b), an output line division step occurs between row V3 (the bottom row of region R1) and row V4 (the top row of region R2) adjacent to row V3. Therefore, the correction coefficient switching signal is "1" at the timing of row V4's readout, and "0" at other times. That is, the correction coefficient K1 is applied to the correction of the output signal of row V4, and the correction coefficient K0 is applied to the correction of the output signals of rows other than row V4 (rows before row V3 and rows after row V5). This improves the tracking performance in the correction of the output signal of row V4. As shown in Figures 11(a) and 11(b), the correction value level C3 generated using the output signal shown in Figure 11(a) follows the output line division step well.

[0074] Figures 12(a) and 12(b) schematically show the signal levels of each row after correction. As shown in Figure 12(a), the shading component and the output line division step component are removed, and the signal level of each row is uniform. As shown in Figure 12(b), the shading component and the output line division step component are removed, and the signal level is uniform in both the corrected signal acquisition area 11b and the effective pixel area 11a. Thus, in the examples of Figures 12(a) and 12(b), appropriate correction is performed even when output line division steps may occur.

[0075] In this embodiment, as shown in Figure 1, two vertical output lines are arranged to correspond to pixels P in one column. In such a configuration, as shown in Figures 7(a) and 7(b), noise may occur in the output signal due to the switching of the vertical output lines Ha and Hb from which the signal is read. In this embodiment, the correction coefficient is switched at the timing when the region R1 where the pixels P to which vertical output line Ha is connected are located and the region R2 where the pixels P to which vertical output line Hb is connected are located switch during scanning. This switching is performed within the 1-frame period in which the vertical scanning unit 13 performs one scan.

[0076] As described above, by switching the correction coefficient, it is possible to obtain a correction value that closely tracks noise. Therefore, according to this embodiment, a photoelectric conversion device is provided that can improve the quality of the output image.

[0077] In generating and acquiring the correction coefficient switching signal, the method for detecting the timing of the switching between the vertical output lines Ha and Hb from which the signal is read is not particularly limited. For example, the vertical scanning unit 13 may generate a flag to transmit the above-mentioned switching timing, and the signal processing unit 18 may receive this flag. This allows the signal processing unit 18 to appropriately set the switching timing of the correction coefficient. Alternatively, the signal processing unit 18 may refer to a setting value indicating the above-mentioned switching timing from, for example, the control unit 12.

[0078] Furthermore, the correction coefficient switching signal may be set to a value of "1" that selects the correction coefficient K1 not only at the moment when the vertical output lines Ha and Hb from which the signal is read switch, but also for a predetermined period after the vertical output lines Ha and Hb from which the signal is read switch. Alternatively, the correction coefficient switching signal may be set to a value of "1" that selects the correction coefficient K1 for a predetermined period from before the vertical output lines Ha and Hb from which the signal is read switch until after. In other words, the correction coefficient switching signal may be set to a value of "1" that selects the correction coefficient K1 within a predetermined number of row control periods including the timing when the vertical output lines Ha and Hb from which the signal is read switch, and may be set to a value of "0" that selects the correction coefficient K0 during other row control periods.

[0079] [Second Embodiment] This embodiment describes a modified method for setting the correction coefficient. In this embodiment, elements common to the first embodiment may be omitted or simplified in their explanation.

[0080] In the first embodiment, it is assumed that the difference in shading components between region R1, where a pixel P whose signal is read out on vertical output line Ha is located, and region R2, where a pixel P whose signal is read out on vertical output line Hb is located, is sufficiently small. Therefore, in the first embodiment, a single correction coefficient K0 is applied everywhere except at the boundary between these two regions. However, there are cases where the shading components differ between region R1 and region R2 due to reasons such as significantly different paths of vertical output lines Ha and Hb. In this embodiment, a correction method that takes such cases into consideration will be described.

[0081] Figure 13 is a block diagram of the signal processing unit 18 according to this embodiment. In this embodiment, the correction coefficient selection unit 182c receives a correction coefficient switching signal and correction coefficients K0, K1, and K2 as inputs. That is, the difference from Figure 8 is that in Figure 13, three types of correction coefficients are input to the correction coefficient selection unit 182c. The values ​​of the correction coefficient switching signal are "2", "1", and "0". The correction coefficient selection unit 182c selects the correction coefficient K2 (second correction coefficient) when the correction coefficient switching signal is "2", and selects the correction coefficient K1 (first correction coefficient) when the correction coefficient switching signal is "1". The correction coefficient selection unit 182c also selects the correction coefficient K0 (third correction coefficient) when the correction coefficient switching signal is "0".

[0082] Figure 14 is a flowchart of the black level correction method according to this embodiment. The processes in steps S11, S12, S16, and S17 are the same as in Figure 10, so their explanation is omitted.

[0083] In step S21, the correction coefficient selection unit 182c determines whether the value of the input correction coefficient switching signal is "2". If the correction coefficient switching signal is "2" in step S21 (YES in step S21), the process proceeds to step S22. In step S22, the correction coefficient selection unit 182c selects the correction coefficient K2 and outputs it to the attenuation unit 182d. The process then proceeds to step S16. If the correction coefficient switching signal is not "2" in step S21 (NO in step S21), the process proceeds to step S23.

[0084] In step S23, the correction coefficient selection unit 182c determines whether the value of the input correction coefficient switching signal is "1". In step S23, if the correction coefficient switching signal is "1" (YES in step S23), the process proceeds to step S24. In step S24, the correction coefficient selection unit 182c selects the correction coefficient K1 and outputs it to the attenuation unit 182d. The process then proceeds to step S16. In step S23, if the correction coefficient switching signal is not "1" (NO in step S23), the process proceeds to step S25. In step S25, the correction coefficient selection unit 182c selects the correction coefficient K0 and outputs it to the attenuation unit 182d. The process then proceeds to step S16.

[0085] Figures 15(a) and 15(b) schematically show the signal level and correction coefficient switching signal of each row before correction according to this embodiment. Figures 15(a) and 15(b) show the change in the correction value level C4 and the correction coefficient switching signal. Similar to Figures 11(a) and 11(b), a step in the output line division occurs between row V3 and row V4 in Figures 15(a) and 15(b). At the timing of reading row V4, the correction coefficient switching signal is "2", and the correction coefficient K2 is applied to correct the output signal of row V4. At the timing of reading rows before row V3, the correction coefficient switching signal is "0", and the correction coefficient K0 is applied to correct the output signal of rows before row V3. At the timing of reading rows from row V5 onwards, the correction coefficient switching signal is "1", and the correction coefficient K1 is applied to correct the output signal of rows before row V5.

[0086] It is desirable that the attenuation coefficient of the attenuation section 182d, set by the correction coefficient K2, be smaller than the attenuation coefficient of the attenuation section 182d, set by the correction coefficients K0 and K1. This setting allows for higher tracking performance of the IIR filter when the correction coefficient K2 is set compared to when the correction coefficients K0 and K1 are set. As a result, the correction coefficient switches at the timing when the vertical output lines Ha and Hb, from which the signal is read out, switch, enabling the generation of a correction value with high tracking performance. This effectively compensates for the effects of output line splitting steps.

[0087] Furthermore, in this embodiment, the correction coefficient K0 applied to the correction of the output signals of rows V3 and earlier, and the correction coefficient K1 applied to the correction of the output signals of rows V5 and earlier, are different from each other. This allows for correction that takes into account the difference in shading components between rows before and after row V4. For example, as shown in Figures 15(a) and 15(b), it is conceivable that the shading components of rows V5 and earlier are larger than those of rows V3 and earlier. In this case, it is desirable that the attenuation coefficient of the attenuation section 182d set by the correction coefficient K1 is smaller than the attenuation coefficient of the attenuation section 182d set by the correction coefficient K0. With this setting, the tracking performance of the IIR filter can be improved when the correction coefficient K1 is set compared to when the correction coefficient K0 is set, and the shading components can be corrected more effectively.

[0088] As described above, in this embodiment, in addition to obtaining the same effects as in the first embodiment, suitable correction is also performed when the shading characteristics change before and after the row in which the vertical output lines Ha and Hb from which the signal is read out are switched. Therefore, according to this embodiment, a photoelectric converter capable of improving the quality of the output image is provided.

[0089] [Third Embodiment] This embodiment describes modified examples of the arrangement of vertical output lines and the method for setting the correction coefficient. In this embodiment, elements common to the first or second embodiment may be omitted or simplified in their description.

[0090] In the first and second embodiments, examples are shown in which two vertical output lines correspond to pixels P in one column. In this case, the timing of the switching of the vertical output line from which the signal is read out is once per scan. However, two or more vertical output lines may be arranged to correspond to pixels P in one column. In this case, the timing of the switching of the vertical output line from which the signal is read out is two or more times per scan. In this embodiment, a correction method considering the case in which three vertical output lines correspond to pixels P in one column will be described. The same applies when four or more vertical output lines correspond to pixels P in one column.

[0091] Figure 16 is a block diagram showing an example configuration of the photoelectric conversion device 1 according to this embodiment. The differences between Figure 16 and Figure 1 will be explained in detail. The pixel array 11 has a plurality of pixels P arranged in a plurality of rows and a plurality of columns. The pixels P may include photoelectric conversion elements. In Figure 16, pixels P arranged in a matrix of 2m columns × 3n rows are shown as rectangular blocks. The vertical scanning unit 13 supplies control signals to the pixels P row by row via control lines V(1) to V(3n) arranged for each row of the pixel array 11.

[0092] In this embodiment, in addition to the vertical output lines Ha(1) to Ha(2m) and Hb(1) to Ha(2m), vertical output lines Hc(1) to Hc(2m) are further arranged to correspond to the first to second m columns, respectively. Each of the vertical output lines Hc(1) to Hc(2m) (third output line) is connected to the pixels P from the (2n+1)th row to the 3nth row of the corresponding column in region R3 (third region). In this embodiment, three vertical output lines are arranged to correspond to pixels P in one column.

[0093] The configuration of the correction value generation unit 182 in this embodiment is the same as in Figure 13. That is, there are three types of correction coefficient switching signals: "2", "1", and "0". The correction coefficient selection unit 182c selects the correction coefficient K2 (fourth correction coefficient) when the correction coefficient switching signal is "2", the correction coefficient K1 (second correction coefficient) when the correction coefficient switching signal is "1", and the correction coefficient K0 (first correction coefficient) when the correction coefficient switching signal is "0".

[0094] Figures 17(a) and 17(b) schematically show the signal levels of each row before correction and the correction coefficient switching signals according to this embodiment. In Figures 17(a) and 17(b), row V3 is the bottom row of the region where the signal is read out to the vertical output line Ha, and row V4 is the top row of the region where the signal is read out to the vertical output line Hb. Row V5 is the row following row V4. That is, row V5 is the second row in the region where the signal is read out to the vertical output line Hb. Row V6 is the bottom row of the region where the signal is read out to the vertical output line Hb, and row V7 (the fourth pixel row) is the top row of the region where the signal is read out to the vertical output line Hc. Row V8 is the row following row V7. That is, row V8 is the second row in the region where the signal is read out to the vertical output line Hc.

[0095] As shown in Figures 17(a) and 17(b), output line splitting steps occur in two places: between row V3 and row V4, and between row V6 and row V7. Therefore, the correction coefficient switching signal is "1" at the timing of row V4's readout, "2" at the timing of row V7's readout, and "0" at other times. In other words, correction coefficient K1 is applied to the correction of the output signal of row V4, correction coefficient K2 is applied to the correction of the output signal of row V7, and correction coefficient K0 is applied to the correction of the output signals of the other rows. This improves the tracking performance in the correction of the output signals of row V4 and row V7. As shown in Figures 17(a) and 17(b), the correction value level C5 generated using the output signal shown in Figure 17(a) follows the output line splitting steps well.

[0096] It is desirable that the attenuation coefficient of the attenuation section 182d, set by the correction coefficients K1 and K2, be smaller than the attenuation coefficient of the attenuation section 182d, set by the correction coefficient K0. This setting allows for higher tracking performance of the IIR filter when correction coefficients K1 and K2 are set compared to when correction coefficient K0 is set. As a result, the correction coefficient switches at the timing when the vertical output lines Ha, Hb, and Hc from which the signal is read out switch, enabling the generation of correction values ​​with high tracking performance. This effectively compensates for the effects of output line division steps.

[0097] As in this embodiment, two or more vertical output lines may be arranged so that each pixel P in a single column corresponds to one. In this case, as described above, there are two or more timings in which the vertical output line from which the signal is read out switches for each scan. By switching the correction coefficient at each timing in which the vertical output line switches, the output line division step can be suitably corrected. Therefore, according to this embodiment, a photoelectric converter capable of improving the quality of the output image is provided.

[0098] Furthermore, the correction coefficients K1 and K2 may be different values ​​or the same value. Also, similar to the second embodiment, the correction coefficient applied to the correction of the output signals of rows V3 and earlier may be different from the correction coefficient applied to the correction of the output signals of rows V5 to V6. Moreover, the correction coefficient applied to the correction of the output signals of rows V5 to V6 may be different from the correction coefficient applied to the correction of the output signals of rows V8 and later.

[0099] [Fourth Embodiment] Figure 18 shows an example of the configuration of the imaging system 1100 according to this embodiment. The imaging system 1100 is an example of a device incorporating the photoelectric converter 1 of the first to third embodiments described above. The imaging system 1100 includes a signal generation unit 1101, a signal correction unit 1102, a CPU 1103, an external input unit 1104, an optical system 1105, an image display unit 1106, a recording unit 1107, and a drive system 1108.

[0100] The signal correction unit 1102 may be the signal processing unit 18 described above. The signal generation unit 1101 may include the pixel array 11, control unit 12, vertical scanning unit 13, readout circuit unit 14, AD conversion unit 15, memory unit 16, horizontal scanning unit 17, etc. Therefore, the signal generation unit 1101 and the signal correction unit 1102 may be the photoelectric converter 1 described above.

[0101] The optical system 1105 is the part that directs light into the light-receiving section of the signal generation unit 1101, and may include lenses, apertures, etc. The signal generation unit 1101 generates an analog image signal by photoelectric conversion of the incident light. The signal generation unit 1101 generates and outputs image data by performing AD conversion on this analog signal. The signal correction unit 1102 performs correction processing on the image data so that it can be output to and stored in the image display unit 1106 or the recording unit 1107. The image display unit 1106 displays an image using the corrected display image data. The recording unit 1107 stores the display image data. The CPU 1103 is a processor that controls and performs calculations for the entire imaging system 1100. The drive system 1108 performs, for example, focus adjustment and aperture adjustment of the optical system 1105. The external input unit 1104 may be a button or the like that the user uses to input imaging conditions, operate the shutter, etc. The video display unit 1106 may be a touch panel, and the touch panel may function as part of the external input unit 1104.

[0102] According to this embodiment, a device is provided that incorporates the photoelectric converter 1 of the first to third embodiments.

[0103] [Fifth Embodiment] A fifth embodiment of the present invention will be described with reference to Figure 19. Figure 19 is a block diagram showing the schematic configuration of the device according to this embodiment.

[0104] Figure 19 is a schematic diagram showing an instrument EQP including a photoelectric converter APR. The photoelectric converter APR has the functions of the photoelectric converter 1 of the first to third embodiments. All or part of the photoelectric converter APR is a semiconductor device IC. The photoelectric converter APR in this example can be used as, for example, an image sensor, an AF (Auto Focus) sensor, a photometering sensor, a distance measuring sensor, etc. The semiconductor device IC has a pixel area PX in which pixel circuits PXC including a photoelectric conversion unit are arranged in a matrix. The semiconductor device IC may have a peripheral area PR around the pixel area PX. Circuits other than pixel circuits can be arranged in the peripheral area PR.

[0105] The photoelectric converter APR may have a stacked structure (chip stacking structure) comprising a first semiconductor chip equipped with multiple photoelectric conversion units and a second semiconductor chip equipped with peripheral circuits. Each peripheral circuit on the second semiconductor chip can be a column circuit corresponding to a pixel row on the first semiconductor chip. Alternatively, each peripheral circuit on the second semiconductor chip can be a matrix circuit corresponding to a pixel or pixel block on the first semiconductor chip. For connecting the first and second semiconductor chips, through-swivel electrodes (TSVs), direct bonding of conductors such as copper for inter-chip wiring, connection by microbumps between chips, or connection by wire bonding can be employed.

[0106] The photoelectric converter APR may include a semiconductor device IC as well as a package PKG that houses the semiconductor device IC. The package PKG may include a substrate on which the semiconductor device IC is fixed, a lid made of glass or the like that faces the semiconductor device IC, and connecting members such as bonding wires and bumps that connect terminals provided on the substrate to terminals provided on the semiconductor device IC.

[0107] The EQP device may further comprise at least one of the following: an optical device OPT, a control unit CTRL, a processing unit PRCS, a display device DSPL, a memory device MMRY, and a mechanical device MCHN. The optical device OPT corresponds to the photoelectric converter APR as a photoelectric converter, and is, for example, a lens, shutter, or mirror. The control unit CTRL controls the photoelectric converter APR and is, for example, a semiconductor device such as an ASIC. The processing unit PRCS processes the signals output from the photoelectric converter APR and constitutes an AFE (analog front end) or a DFE (digital front end). The processing unit PRCS is a semiconductor device such as a CPU (central processing unit) or an ASIC (application-specific integrated circuit). The display device DSPL is an EL display device, liquid crystal display device, etc., that displays the information (image) obtained by the photoelectric converter APR. The memory device MMRY is a magnetic device, semiconductor device, etc., that stores the information (image) obtained by the photoelectric converter APR. The memory device MMRY is a volatile memory such as SRAM or DRAM, or a non-volatile memory such as flash memory or a hard disk drive. The mechanical device MCHN has movable parts or propulsion parts such as motors and engines. The device EQP displays the signal output from the photoelectric converter APR on the display device DSPL, or transmits it to the outside using a communication device (not shown) provided by the device EQP. For this purpose, it is preferable that the device EQP further includes a memory device MMRY and a processing device PRCS, separate from the memory circuit and arithmetic circuit of the photoelectric converter APR.

[0108] The EQP (Equipment Equipped Device) shown in Figure 19 can be an electronic device such as an information terminal with imaging capabilities (e.g., smartphones and wearable devices), or a camera (e.g., interchangeable lens cameras, compact cameras, video cameras, and surveillance cameras). In a camera, the mechanical device MCHN can drive components of the optical device OPT for zooming, focusing, and shutter operation. The EQP can also be a transport device (mobile object) such as a vehicle, ship, or aircraft. Furthermore, the EQP can be a medical device such as an endoscope or CT scanner.

[0109] The mechanical device MCHN in transport equipment can be used as a mobile device. The device EQP as transport equipment is suitable for transporting the photoelectric converter APR, assisting and / or automating driving (operation) through its imaging function, etc. The processing device PRCS for assisting and / or automating driving (operation) can perform processing to operate the mechanical device MCHN as a mobile device based on information obtained from the photoelectric converter APR.

[0110] The photoelectric converter APR according to this embodiment can provide high value to its designers, manufacturers, distributors, buyers, and / or users. Therefore, by installing the photoelectric converter APR in the EQP (Equipment Equipment), the value of the EQP can also be increased. Thus, when manufacturing and selling the EQP, deciding to install the photoelectric converter APR of this embodiment in the EQP is advantageous in increasing the value of the EQP.

[0111] [Sixth Embodiment] Figures 20(a) and 20(b) are block diagrams of the equipment related to the in-vehicle camera in this embodiment. Figures 20(a) and 20(b) show an example of applying the above-described photoelectric converter 1 to a moving object such as a vehicle. Equipment 80 includes an imaging device 800 (an example of a photoelectric converter) and a signal processing device (processing device) that processes signals from the imaging device 800. Equipment 80 includes an image processing unit 801 that performs image processing on a plurality of image data acquired by the imaging device 800, and a parallax calculation unit 802 that calculates parallax (phase difference of parallax images) from a plurality of image data acquired by Equipment 80. Equipment 80 also includes a distance measurement unit 803 that calculates the distance to an object based on the calculated parallax, and a collision determination unit 804 that determines whether or not there is a possibility of collision based on the calculated distance. Here, the parallax calculation unit 802 and the distance measurement unit 803 are examples of distance information acquisition means that acquire distance information to an object. That is, distance information is information related to parallax, defocus amount, distance to an object, etc. The collision determination unit 804 may use any of this distance information to determine the possibility of a collision. The distance information acquisition means may be implemented by specially designed hardware or by a software module. It may also be implemented by an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), or a combination thereof.

[0112] Device 80 is connected to a vehicle information acquisition device 810 and can acquire vehicle information such as vehicle speed, yaw rate, and steering angle. Device 80 is also connected to a control ECU 820, which is a control device that outputs a control signal to generate braking force on the vehicle based on the collision determination result of the collision determination unit 804. Furthermore, device 80 is connected to a warning device 830 that issues a warning to the driver based on the collision determination result of the collision determination unit 804. For example, if the collision determination result of the collision determination unit 804 indicates a high probability of collision, the control ECU 820 performs vehicle control to avoid a collision or mitigate damage by applying the brakes, releasing the accelerator, or suppressing engine output. The warning device 830 warns the user by sounding an alarm, displaying warning information on a screen such as a car navigation system, or vibrating the seatbelt or steering wheel. As described above, device 80 functions as a control means that controls the actions that control the vehicle.

[0113] In this embodiment, the equipment 80 images the area around the vehicle, for example, in front of or behind it. Figure 20(b) shows the equipment when imaging the area in front of the vehicle (imaging range 850). The vehicle information acquisition device 810, acting as an imaging control means, sends instructions to the equipment 80 or imaging device 800 to perform the imaging operation. This configuration allows for further improvement of the accuracy of distance measurement.

[0114] The above example described controlling a vehicle to avoid collisions with other vehicles, but it can also be applied to control systems that automatically follow other vehicles, or control systems that automatically stay within their lane. Furthermore, the equipment is not limited to vehicles such as automobiles, but can be applied to mobile objects (mobile devices) such as ships, aircraft, satellites, industrial robots, and consumer robots. In addition, it can be applied not only to mobile objects, but also to a wide range of devices that utilize object recognition or biometric recognition, such as intelligent transportation systems (ITS) and surveillance systems.

[0115] [Modified Embodiment] The present invention is not limited to the embodiments described above and can be modified in various ways. For example, an example in which a part of the configuration of one embodiment is added to another embodiment, or an example in which a part of the configuration of one embodiment is replaced with a part of the configuration of another embodiment, is also an embodiment of the present invention.

[0116] Furthermore, the disclosures in this specification include the complement of the concepts described herein. That is, if this specification contains a statement such as "A is greater than B," then even if the statement "A is not greater than B" is omitted, this specification can still be said to disclose that "A is not greater than B." This is because the statement "A is greater than B" presupposes that the case where "A is not greater than B" is being considered.

[0117] The disclosures in this specification include the following components: (Composition 1) A pixel array containing multiple pixels arranged in multiple rows and multiple columns, A first output line and a second output line, each arranged to correspond to one of the aforementioned multiple columns, A correction value generation unit that generates a correction value used for black level correction of the signal output from the pixel array, It has, The pixel array includes a first region containing a contiguous portion of the plurality of rows, and a second region containing other contiguous portions of the plurality of rows and adjacent to the first region. Each row of the first and second regions includes an effective pixel region that outputs a signal corresponding to incident light by photoelectric conversion and a correction signal acquisition region that outputs a correction signal. The first output line is connected to the pixels of the first region, but not to the pixels of the second region. The second output line is connected to the pixels of the second region, but not to the pixels of the first region. The second region includes a first row of pixels and a second row of pixels adjacent to the first region. The correction value generation unit generates a correction value used for black level correction of the signal output from the pixels of the first pixel row based on the first correction coefficient and the correction signal, and generates a correction value used for black level correction of the signal output from the pixels of the second pixel row based on a second correction coefficient different from the first correction coefficient and the correction signal. A photoelectric conversion device characterized by the following features. (Configuration 2) The first region includes the third pixel row, The correction value generation unit generates a correction value used for correcting the black level of the pixels in the third pixel row based on the first correction coefficient and the correction signal. A photoelectric conversion device according to configuration 1, characterized in that it is a photoelectric conversion device. (Composition 3) The third pixel row is adjacent to the second region. The photoelectric conversion device according to configuration 2, characterized in that it is a photoelectric conversion device. (Composition 4) The first region includes the third pixel row, The correction value generation unit generates a correction value used for correcting the black level of the pixels in the third pixel row, based on a third correction coefficient that is different from both the first and second correction coefficients, and the correction signal. A photoelectric conversion device according to configuration 1, characterized in that it is a photoelectric conversion device. (Composition 5) The third pixel row is adjacent to the second region. The photoelectric conversion device according to configuration 4, characterized by the features described above. (Composition 6) The system further includes a third output line arranged to correspond to one of the aforementioned multiple rows, The third output line includes pixels of other consecutive rows among the plurality of rows and is connected to pixels of the third region adjacent to the second region. The first output line is not connected to the pixels of the third region. The second output line is not connected to the pixels of the third region. The third output line is not connected to any of the pixels in the first region or the pixels in the second region. The third region includes a fourth row of pixels adjacent to the second region, The correction value generation unit generates a correction value used for black level correction of the signal output from the pixels of the fourth pixel row, using a fourth correction coefficient different from the first correction coefficient. A photoelectric conversion device according to any one of configurations 1 to 5, characterized by the above. (Composition 7) The correction value generation unit includes a low-pass filter. A photoelectric conversion device according to any one of configurations 1 to 6, characterized by the above. (Composition 8) The first and second correction coefficients correspond to the attenuation coefficients of the low-pass filter. The photoelectric conversion device according to configuration 7, characterized by the features described above. (Composition 9) The attenuation coefficient of the low-pass filter based on the second correction coefficient is smaller than the attenuation coefficient of the low-pass filter based on the first correction coefficient. The photoelectric conversion device according to configuration 8, characterized by the above. (Composition 10) The aforementioned low-pass filter is an IIR (Infinite Impulse Response) filter. A photoelectric conversion device according to any one of the configurations 7 to 9, characterized by the above. (Composition 11) The pixels in the effective pixel region include a photoelectric conversion element. The pixels in the correction signal acquisition region include a photoelectric conversion element and a light-shielding portion that blocks the light incident on the photoelectric conversion element. A photoelectric conversion device according to any one of configurations 1 to 10, characterized by the above. (Composition 12) The pixels in the effective pixel region include a photoelectric conversion element. The pixels in the correction signal acquisition region do not include photoelectric conversion elements. A photoelectric conversion device according to any one of configurations 1 to 10, characterized by the above. (Composition 13) The system further includes a pixel control unit that scans the plurality of pixels so that each of the plurality of pixels sequentially outputs a signal row by row. A photoelectric conversion device according to any one of configurations 1 to 12, characterized by the above. (Composition 14) The correction value generation unit switches between a state in which it generates a correction value based on the first correction coefficient and a state in which it generates a correction value based on the second correction coefficient within one frame period in which the pixel control unit performs one scan. A photoelectric conversion device according to configuration 13, characterized by the features described above. (Composition 15) The pixel control unit outputs a signal to the correction value generation unit indicating the switching timing between the first correction coefficient and the second correction coefficient. A photoelectric conversion device according to configuration 13 or 14, characterized by the above. (Composition 16) The correction value generation unit generates a correction value based on the average value of the correction signals output from the pixels of one row in the correction signal acquisition area. A photoelectric conversion device according to any one of configurations 1 to 15, characterized by the above. (Composition 17) The aforementioned pixel array is arranged on the first substrate, The correction value generation unit is located on a second substrate which is laminated on the first substrate. A photoelectric conversion device according to any one of configurations 1 to 16, characterized by the above. (Composition 18) At least a portion of the first output line and at least a portion of the second output line are arranged on the first substrate. A photoelectric conversion device according to configuration 17, characterized by the features described above. (Composition 19) A photoelectric conversion device as described in any one of items 1 to 18, Optical device corresponding to the aforementioned photoelectric converter, A control device for controlling the aforementioned photoelectric converter, A processing device that processes the signal output from the aforementioned photoelectric converter, A display device that displays information obtained by the aforementioned photoelectric converter. A storage device for storing information obtained by the aforementioned photoelectric converter, and A device characterized by comprising at least one of the following: a mechanical device that operates based on information obtained from the photoelectric converter. (Composition 20) The apparatus according to configuration 19, characterized in that the processing device acquires distance information from the photoelectric converter to the object.

[0118] The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by a process in which one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0119] It should be noted that the embodiments described above are merely examples of how the present invention can be implemented, and the technical scope of the present invention should not be interpreted as being limited by them. In other words, the present invention can be implemented in various ways without departing from its technical concept or its main features. [Explanation of symbols]

[0120] 1. Photoelectric converter 11-pixel array 13 Vertical scanning unit 11a Effective pixel area 11b, 11c Correction signal acquisition area 182 Correction Value Generation Unit Ha, Hb vertical output line P pixels

Claims

1. A pixel array containing multiple pixels arranged in multiple rows and multiple columns, A first output line and a second output line, each arranged to correspond to one of the aforementioned multiple columns, A correction value generation unit that generates a correction value used for black level correction of the signal output from the pixel array, It has, The pixel array includes a first region containing a contiguous portion of the plurality of rows, and a second region containing another contiguous portion of the plurality of rows and adjacent to the first region. Each row of the first and second regions includes an effective pixel region that outputs a signal corresponding to the incident light by photoelectric conversion, and a correction signal acquisition region that outputs a correction signal. The first output line is connected to the pixels of the first region, but not to the pixels of the second region. The second output line is connected to the pixels of the second region, but not to the pixels of the first region. The second region includes a first row of pixels and a second row of pixels adjacent to the first region. The correction value generation unit generates a correction value used for black level correction of the signal output from the pixels of the first pixel row based on the first correction coefficient and the correction signal, and generates a correction value used for black level correction of the signal output from the pixels of the second pixel row based on a second correction coefficient different from the first correction coefficient and the correction signal. A photoelectric conversion device characterized by the following features.

2. The first region includes the third pixel row, The correction value generation unit generates a correction value used for correcting the black level of the pixels in the third pixel row based on the first correction coefficient and the correction signal. The photoelectric conversion device according to feature 1.

3. The aforementioned third pixel row is adjacent to the aforementioned second region. The photoelectric conversion device according to feature 2.

4. The first region includes the third pixel row, The correction value generation unit generates a correction value used for correcting the black level of the pixels in the third pixel row, based on a third correction coefficient that is different from both the first and second correction coefficients, and the correction signal. The photoelectric conversion device according to feature 1.

5. The aforementioned third pixel row is adjacent to the aforementioned second region. The photoelectric conversion device according to feature 4.

6. The system further includes a third output line arranged to correspond to one of the aforementioned multiple rows, The third output line includes pixels of other consecutive rows among the plurality of rows and is connected to pixels of the third region adjacent to the second region. The first output line is not connected to the pixels of the third region. The second output line is not connected to the pixels of the third region. The third output line is not connected to any of the pixels in the first region or the pixels in the second region. The third region includes a fourth pixel row adjacent to the second region, The correction value generation unit generates a correction value used for black level correction of the signal output from the pixels of the fourth pixel row, using a fourth correction coefficient different from the first correction coefficient. The photoelectric conversion device according to feature 1.

7. The correction value generation unit includes a low-pass filter. The photoelectric conversion device according to feature 1.

8. The first and second correction coefficients correspond to the attenuation coefficients of the low-pass filter. The photoelectric conversion device according to feature 7.

9. The attenuation coefficient of the low-pass filter based on the second correction coefficient is smaller than the attenuation coefficient of the low-pass filter based on the first correction coefficient. The photoelectric conversion device according to feature 8.

10. The aforementioned low-pass filter is an IIR (Infinite Impulse Response) filter. The photoelectric conversion device according to feature 7.

11. The pixels in the effective pixel region include a photoelectric conversion element. The pixels in the correction signal acquisition region include a photoelectric conversion element and a light-shielding portion that blocks the light incident on the photoelectric conversion element. The photoelectric conversion device according to feature 1.

12. The pixels in the effective pixel region include a photoelectric conversion element. The pixels in the correction signal acquisition region do not include photoelectric conversion elements. The photoelectric conversion device according to feature 1.

13. The system further includes a pixel control unit that scans the plurality of pixels so that each of the plurality of pixels sequentially outputs a signal row by row. The photoelectric conversion device according to feature 1.

14. The correction value generation unit switches between a state in which it generates a correction value based on the first correction coefficient and a state in which it generates a correction value based on the second correction coefficient within one frame period in which the pixel control unit performs one scan. The photoelectric conversion device according to feature 13.

15. The pixel control unit outputs a signal to the correction value generation unit indicating the switching timing between the first correction coefficient and the second correction coefficient. The photoelectric conversion device according to feature 13.

16. The correction value generation unit generates a correction value based on the average value of the correction signals output from the pixels of one row in the correction signal acquisition area. The photoelectric conversion device according to feature 1.

17. The aforementioned pixel array is arranged on the first substrate, The correction value generation unit is located on a second substrate which is laminated on the first substrate. The photoelectric conversion device according to feature 1.

18. At least a portion of the first output line and at least a portion of the second output line are arranged on the first substrate. The photoelectric conversion device according to feature 17.

19. A photoelectric conversion device according to any one of claims 1 to 18, Optical device corresponding to the aforementioned photoelectric converter, A control device for controlling the aforementioned photoelectric converter, A processing device that processes the signal output from the aforementioned photoelectric converter, A display device that displays information obtained by the aforementioned photoelectric converter. A storage device for storing information obtained by the aforementioned photoelectric converter, and A device characterized by comprising at least one of the following: a mechanical device that operates based on information obtained from the photoelectric converter.

20. The apparatus according to claim 19, characterized in that the processing device acquires distance information from the photoelectric converter to the object.

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