JP2016220022A - Solid-state imaging apparatus and camera module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid-state imaging apparatus which enables accurate focusing and a camera module.SOLUTION: The solid-state imaging apparatus includes a pixel array 20. The pixel array 20 includes an imaging pixel 30 as a first pixel and a phase difference pixel 31 as a second pixel. The second pixel includes a light-shielding layer 46 as a shielding part and a filter 42 as a light intensity adjustment part. The shielding part includes an opening 47 through which a part of light advancing toward a photoelectric conversion part 49 passes. The light intensity adjustment part is provided on the incident side of the shielding part and adjusts the intensity distribution of the light in a two-dimensional direction.SELECTED DRAWING: Figure 4

Description

  The present embodiment relates to a solid-state imaging device and a camera module.

  Conventionally, as one of autofocus methods of a camera module, a method of detecting a shift between the focus of an imaging optical system and a subject using a phase difference pixel of a pixel array and focusing on the subject is known. The camera module detects a displacement between the subject and the focus by observing a positional shift (phase difference) of an image obtained by using phase difference pixels having different aperture positions. The camera module is required to accurately perform focusing on a subject by performing accurate phase difference detection using phase difference pixels.

JP 2014-42354 A

  An object of one embodiment is to provide a solid-state imaging device and a camera module for enabling accurate focusing.

  According to one embodiment, the solid-state imaging device includes a pixel array. The pixel array includes pixels arranged in a matrix. The pixel includes a photoelectric conversion unit. The pixel array includes a first pixel and a second pixel. The first pixel is a pixel for detecting a subject image. The second pixel is a pixel for detecting a shift between the subject and the focus of the imaging optical system. The second pixel includes a shielding part and a light intensity adjusting part. The shielding part has an opening. The opening allows a part of the light traveling to the photoelectric conversion unit to pass through. The light intensity adjusting unit is provided on the incident side of the shielding unit. The light intensity adjusting unit adjusts the light intensity distribution in the two-dimensional direction.

FIG. 1 is a block diagram illustrating a schematic configuration of a camera system including the solid-state imaging device according to the embodiment. FIG. 2 is a block diagram illustrating a schematic configuration of the solid-state imaging device according to the embodiment. FIG. 3 is a plan view schematically showing the configuration of the pixel array shown in FIG. 4 is a cross-sectional view of the imaging pixel and the phase difference pixel shown in FIG. FIG. 5 is a diagram for explaining phase difference detection using the phase difference pixels shown in FIG. FIG. 6 is a diagram illustrating an example of simulating the relationship between contrast and spatial frequency in a comparative example of the embodiment. FIG. 7 is a diagram illustrating an example of simulating the relationship between contrast and spatial frequency in the embodiment.

  Exemplary embodiments of a solid-state imaging device and a camera module will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment.

(Embodiment)
FIG. 1 is a block diagram illustrating a schematic configuration of a camera system including the solid-state imaging device according to the embodiment. The camera system 1 is an electronic device that includes a camera module 2. The camera system 1 is a mobile terminal with a camera, for example. The camera system 1 may be an electronic device such as a digital camera.

  The camera system 1 includes a camera module 2 and a post-processing unit 3. The camera module 2 includes a lens module 4 and a solid-state imaging device 5. The lens module 4 includes an imaging optical system 6 and a lens driving unit 7.

  The imaging optical system 6 takes in light from the subject. The imaging optical system 6 includes a lens that forms a subject image. The lens driving unit 7 is a driving mechanism that moves the lens of the imaging optical system 6.

  The solid-state imaging device 5 includes an image sensor 8, a signal processing circuit 9, and an autofocus (AF) driver 10. The image sensor 8 captures a subject image. The signal processing circuit 9 processes the image signal from the image sensor 8. The AF driver 10 which is a focus adjusting unit adjusts the focus of the imaging optical system 6 under the control of the lens driving unit 7. The AF driver 10 generates a control signal for controlling the lens driving unit 7 based on the signal from the signal processing circuit 9. The AF driver 10 outputs a control signal to the lens driving unit 7.

  The image sensor 8 is a backside illumination type CMOS (Complementary Metal Oxide Semiconductor) image sensor. In the back-illuminated CMOS image sensor, a wiring layer is provided on the opposite side of the semiconductor layer including the photoelectric conversion portion from the side on which incident light is incident. Note that the image sensor 8 is not limited to a back-illuminated CMOS image sensor, and may be a front-illuminated CMOS image sensor, a CCD (Charge Coupled Device), or the like.

  The post-processing unit 3 includes an image signal processor (ISP) 11, a storage unit 12, and a display unit 13. The ISP 11 performs signal processing of an image signal obtained by imaging with the solid-state imaging device 5. The storage unit 12 stores an image that has undergone signal processing in the ISP 11. The storage unit 12 outputs an image signal to the display unit 13 in accordance with a user operation or the like.

  The display unit 13 displays an image according to the image signal input from the ISP 11 or the storage unit 12. The display unit 13 is, for example, a liquid crystal display. The camera system 1 performs feedback control of the solid-state imaging device 5 based on data that has undergone signal processing in the ISP 11.

  FIG. 2 is a block diagram illustrating a schematic configuration of the solid-state imaging device according to the embodiment. The image sensor 8 includes a pixel array 20, a control circuit 21, a row scanning circuit 22, a column scanning circuit 23, and a column processing circuit 24.

  The pixel array 20 is provided in the imaging region of the image sensor 8. The control circuit 21, the row scanning circuit 22, the column scanning circuit 23, the column processing circuit 24, the signal processing circuit 9, and the AF driver 10 constitute a peripheral circuit unit of the pixel array 20.

  The pixel array 20 includes pixels arranged in a matrix. Each pixel includes a photodiode which is a photoelectric conversion unit. The photoelectric conversion unit generates signal charges corresponding to the amount of incident light. The pixel accumulates signal charges generated according to the amount of incident light.

  Various data and clock signals for driving the solid-state imaging device 5 are supplied to the control circuit 21 from the outside of the solid-state imaging device 5. The control circuit 21 generates various pulse signals for controlling driving of the circuit unit in accordance with the clock signal. The control circuit 21 supplies a pulse signal instructing drive timing to the row scanning circuit 22, the column scanning circuit 23, the column processing circuit 24 and the signal processing circuit 9.

  The row scanning circuit 22 includes a shift register and an address decoder. The row scanning circuit 22 which is a pixel driving circuit supplies a driving signal to the pixels of the pixel array 20. The control circuit 21 supplies a pulse signal corresponding to the vertical synchronization signal to the row scanning circuit 22. The row scanning circuit 22 sequentially selects pixel rows from which pixel signals are read according to the pulse signal from the control circuit 21. The row scanning circuit 22 performs readout scanning by sequentially supplying a readout signal for each pixel in the selected pixel row. The read signal is a drive signal for reading a pixel signal generated according to the amount of incident light from the pixel.

  The row scanning circuit 22 performs sweep-out scanning by supplying a reset signal to each pixel prior to supplying a readout signal to each pixel. The reset signal is a drive signal for discharging the charge remaining in the pixel. Each pixel accumulates signal charges generated according to the amount of incident light from when the reset signal is supplied to when the readout signal is supplied.

  The drive signal is transmitted from the row scanning circuit 22 to each pixel through the pixel drive line 25. The pixel drive line 25 is provided for each pixel row of the pixel array 20. A pixel row consists of pixels arranged in the row direction.

  The pixel signal is transmitted from each pixel to the column processing circuit 24 through the vertical signal line 26. The vertical signal line 26 is provided for each pixel column of the pixel array 20. The pixel column is composed of pixels arranged in the column direction.

  The column processing circuit 24 processes the pixel signal transmitted through the vertical signal line 26 by a unit circuit (not shown) provided for each pixel column. The column processing circuit 24 performs correlated double sampling processing (CDS) for reducing fixed pattern noise on the pixel signal. The column processing circuit 24 performs AD conversion, which is conversion from an analog signal to a digital signal, on the pixel signal. The column processing circuit 24 may perform processing other than CDS and AD conversion. The column processing circuit 24 holds the pixel signal that has undergone CDS and AD conversion for each unit circuit.

  The column scanning circuit 23 includes a shift register and an address decoder. The control circuit 21 supplies a pulse signal corresponding to the horizontal synchronization signal to the column scanning circuit 23. The column scanning circuit 23 sequentially selects pixel columns from which pixel signals are read according to the pulse signal from the control circuit 21. The column processing circuit 24 sequentially outputs pixel signals held in each unit circuit in accordance with the selective scanning by the column scanning circuit 23. The image sensor 8 outputs an image signal having the pixel signal from the column processing circuit 24 as a component.

  The signal processing circuit 9 performs various signal processes on the image signal from the image sensor 8. The signal processing circuit 9 performs signal processing such as scratch correction, gamma correction, noise reduction processing, lens shading correction, white balance adjustment, distortion correction, and resolution restoration. The solid-state imaging device 5 outputs the image signal that has undergone signal processing in the signal processing circuit 9 to the subsequent processing unit 3.

  The camera system 1 may be configured such that the ISP 11 of the post-stage processing unit 3 performs at least one of the signal processing performed by the signal processing circuit 9 in the present embodiment. In the camera system 1, at least one of the signal processing may be performed by both the signal processing circuit 9 and the ISP 11. The signal processing circuit 9 and the ISP 11 may perform signal processing other than the signal processing described in the present embodiment.

  The AF driver 10 detects a shift between the subject and the focus of the imaging optical system 6 based on the signal from the signal processing circuit 9. The AF driver 10 generates a control signal for matching the focus to the subject based on the result of detecting the deviation between the subject and the focus of the imaging optical system 6. The lens driving unit 7 moves the lens of the imaging optical system 6 in accordance with a control signal from the AF driver 10.

  FIG. 3 is a plan view schematically showing a partial configuration of the pixel array shown in FIG. The pixel array 20 includes an imaging pixel 30 and a phase difference pixel 31. The imaging pixel 30 as the first pixel is a pixel for detecting a subject image. The phase difference pixel 31 as the second pixel is a pixel for detecting a shift between the focus of the imaging optical system 6 and the subject.

  In FIG. 3, “R”, “G”, and “B” represent a red (R) pixel, a green (G) pixel, and a blue (B) pixel, which are the imaging pixels 30, respectively. Each of the R pixel, the G pixel, and the B pixel includes a color filter described later. The color filter of the R pixel selectively transmits R light. The color filter of the G pixel selectively transmits G light. The color filter of the B pixel selectively transmits B light.

  The imaging pixels 30 and the phase difference pixels 31 are arranged in a regular array with a 2 × 2 pixel block as a unit. An R pixel and a B pixel are arranged at one diagonal of the pixel block, and a G pixel and a phase difference pixel 31 are arranged at the other diagonal.

  A hatched portion of the phase difference pixel 31 illustrated in FIG. 3 indicates a portion covered with a light shielding layer. The phase difference pixel 31R is the phase difference pixel 31 in which an opening is formed in the right half region in the drawing. The left half region of the phase difference pixel 31R is covered with a light shielding layer. The phase difference pixel 31L is the phase difference pixel 31 in which an opening is formed in the left half region. The right half region of the phase difference pixel 31L is covered with a light shielding layer.

  The signal processing circuit 9 described above outputs a signal from the phase difference pixel 31 to the AF driver 10. The signal processing circuit 9 performs interpolation processing for generating image information at the position of the phase difference pixel 31 using the signal from the imaging pixel 30.

  4 is a cross-sectional view of the imaging pixel and the phase difference pixel shown in FIG. FIG. 4 shows imaging pixels 30 and phase difference pixels 31 that are adjacent to each other in the pixel array 20 shown in FIG. 3. The phase difference pixel 31 illustrated in FIG. 4 is the phase difference pixel 31R illustrated in FIG.

  The pixel array 20 includes a microlens 40, a microlens fixing layer 41, a color filter 43, a transparent layer 44, a planarization layer 45, a light shielding layer 46, a semiconductor layer 48, an insulating layer 52, an adhesive layer 51, and a support substrate 50.

  The semiconductor layer 48 includes a plurality of N-type silicon regions 48b and a P-type silicon region 48a around the N-type silicon region 48b. The photoelectric conversion unit 49 that is a photodiode is formed by a PN junction between a P-type silicon region 48a and an N-type silicon region 48b. Each photoelectric conversion unit 49 constitutes the imaging pixel 30 or the phase difference pixel 31. An element isolation region (not shown) is provided between the photoelectric conversion portions 49 in the semiconductor layer 48. The element isolation region electrically isolates the photoelectric conversion units 49 from each other.

  The microlens 40 that is a lens element is provided in each imaging pixel 30 and each phase difference pixel 31. The microlens 40 collects the light incident on the pixel array 20 and advances the light to the photoelectric conversion unit 49.

  The color filter 43 is provided in the imaging pixel 30. The color filter 43 selectively transmits predetermined color light out of the light from the microlens 40. The microlens 40 of the imaging pixel 30 is fixed to the color filter 43 via the microlens fixing layer 41. The microlens fixing layer 41 is a layer made of a transparent member.

  The transparent layer 44 is provided in the phase difference pixel 31. The transparent layer 44 is a layer made of a transparent member. The transparent layer 44 transmits light from the microlens 40. The microlens 40 of the phase difference pixel 31 is fixed to the transparent layer 44 via the microlens fixing layer 41. The phase difference pixel 31 may be provided with a color filter 43 in the same manner as the imaging pixel 30 instead of the transparent layer 44.

  The planarizing layer 45 constitutes a flat surface on the light shielding layer 46. The planarization layer 45 is a layer made of a transparent member. The light shielding layer 46 constitutes a shielding part that shields light. The light shielding layer 46 is a layer containing a metal material that reflects light. The light shielding layer 46 may be a layer containing a light absorbing material. An opening 47 for allowing light to pass through is formed in the light shielding layer 46 for each pixel.

  The light shielding layer 46 shields light, for example, in the vicinity of the upper part of the element isolation region in the peripheral portion of the imaging pixel 30. In the imaging pixel 30, the center of the opening 47 coincides with the center of the photoelectric conversion unit 49. In the phase difference pixel 31, the light shielding layer 46 is formed so as to cover almost half of the phase difference pixel 31. In the planar configuration shown in FIG. 3, the region of the phase difference pixel 31 is divided into a region covered with the light shielding layer 46 and a region of the opening 47.

  In the phase difference pixel 31 shown in FIG. 4, a region on the right side from the central axis N is an opening 47, and a region on the left side from the central axis N is a light shielding layer 46. In the phase difference pixel 31, the center of the opening 47 is at a position shifted to the right from the center of the photoelectric conversion unit 49. The central axis N is an axis that passes through the center position of the phase difference pixel 31 and is perpendicular to the light receiving surface of the semiconductor layer 48. The central axis N passes through the center of the photoelectric conversion unit 49 and the center of the microlens 40. The central axis N may be an axis that coincides with the optical axis of the microlens 40.

  The filter 42 is provided in the area of each phase difference pixel 31 in the microlens fixing layer 41. The filter 42 is a light intensity adjusting unit provided between the microlens 40 and the light shielding layer 46 in the phase difference pixel 31. The filter 42 adjusts the light intensity distribution in a two-dimensional direction perpendicular to the central axis N.

  The filter 42 includes a light-absorbing material. The filter 42 is made of, for example, a resin material containing a black pigment. The filter 42 is formed so that the thickness in the direction of the central axis N, which is a direction perpendicular to the two-dimensional direction, increases as the distance from the central axis N increases. The first surface of the filter 42 on the microlens 40 side has a concave curved surface. The curved surface may be either a spherical surface or an aspherical surface. The curved surface may be a conical surface or a surface having a shape close to a conical surface. The second surface of the filter 42 on the transparent layer 44 side is a flat surface.

  The filter 42 is formed by changing the thickness in this way, and thus transmits light with a higher transmittance as it is closer to the central axis N. The filter 42 adjusts the light intensity distribution by transmitting light at different transmittances for each position in the two-dimensional direction. The filter 42 is formed, for example, by etching a film of a light absorbing material.

  The insulating layer 52 is provided on the side of the semiconductor layer 48 opposite to the side on which incident light is incident. A wiring layer 53 is provided inside the insulating layer 52. The insulating layer 52 electrically insulates the wiring layers 53 from each other. The adhesive layer 51 joins the support substrate 50 and the insulating layer 52 of the pixel array 20.

  3 includes a row in which B pixels and phase difference pixels 31R are alternately arranged, and a row in which B pixels and phase difference pixels 31L are alternately arranged. The number and position of the phase difference pixels 31R and 31L are arbitrarily set as appropriate. The phase difference pixel 31R and the phase difference pixel 31L may be arranged in the same row. The phase difference pixels 31 </ b> R and 31 </ b> L are arranged in a partial region of the pixel array 20 or the entire pixel array 20.

  FIG. 5 is a diagram for explaining phase difference detection using the phase difference pixels shown in FIG. The center in the figure shows the imaging optical system 6 and the pixel array 20 in a focused state where the imaging optical system 6 is in focus with the subject. The left side of the figure shows the imaging optical system 6 and the pixel array 20 in a so-called rear pin state in which the focus of the imaging optical system 6 is at a position behind the subject. The right side of the drawing shows the imaging optical system 6 and the pixel array 20 in a so-called front pin state in which the focal point of the imaging optical system 6 is located in front of the subject. Further, for each state, a signal level distribution SR detected by each phase difference pixel 31R of the pixel array 20 and a signal level distribution SL detected by each phase difference pixel 31L are shown.

  The solid-state imaging device 5 simultaneously acquires an image obtained by each phase difference pixel 31R that is a first phase difference pixel and an image obtained by each phase difference pixel 31L that is a second phase difference pixel. The solid-state imaging device 5 performs imaging by a so-called pupil division method by using phase difference pixels 31R and 31L in which the openings 47 are symmetric with respect to each other. Each of the phase difference pixel 31R and the phase difference pixel 31L has an angle dependency in sensitivity.

  In the in-focus state, the image obtained by each phase difference pixel 31R matches the image obtained by each phase difference pixel 31L. The phase difference between SR, which is the output of each phase difference pixel 31R, and SL, which is the output of each phase difference pixel 31L, is zero.

  In a state where the focus of the imaging optical system 6 is deviated from the subject, there is a deviation between the image obtained by each phase difference pixel 31R and the image obtained by each phase difference pixel 31L. In the rear pin state, the SL peak is shifted to the left in the figure with respect to the SR peak. The phase difference when the SL peak shifts to the left with respect to the SR peak is defined as a negative phase difference. In the front pin state, the SL peak is shifted to the right in the figure with respect to the SR peak. The phase difference in the case where the SL peak shifts to the right side with respect to the SR peak in this way is defined as a positive phase difference.

  The AF driver 10 detects the phase difference between the image obtained by each phase difference pixel 31R and the image obtained by each phase difference pixel 31L together with a plus or minus sign. The AF driver 10 detects a deviation between the subject and the focus of the imaging optical system 6 based on the detected phase difference. The AF driver 10 obtains the direction and amount of movement of the lens for eliminating the focus shift. The AF driver 10 may refer to a table representing the relationship between the phase difference and the lens movement amount. The AF driver 10 generates a control signal for moving the lens with the obtained direction and movement amount.

  The phase difference pixel 31 may generate diffracted light due to the diffraction phenomenon of light that has passed through the opening 47. The generation of diffracted light in the phase difference pixel 31 may affect the detection result of the light intensity in the phase difference pixel 31. As an influence of the diffracted light, the signal output characteristic of the phase difference pixel 31 may change so that a peak different from the original peak is generated when the light intensity around the principal ray is enhanced by the diffracted light. . For this reason, the solid-state imaging device 5 may cause a decrease in detection accuracy of the phase difference when in the defocused state.

  In the solid-state imaging device 5 of the embodiment, the filter 42 adjusts the intensity distribution of light traveling from the microlens 40 of the phase difference pixel 31 to the photoelectric conversion unit 49. The light transmitted through the filter 42 has a gradation in which the intensity decreases with increasing the distance from the central axis N with the central axis N as a peak.

  Here, improvement in the accuracy of phase difference detection by adjusting the light intensity distribution in the embodiment will be described. FIG. 6 is a diagram illustrating an example of simulating the relationship between contrast and spatial frequency in a comparative example of the embodiment. FIG. 7 shows an example of simulating the relationship between contrast and spatial frequency in the embodiment.

  An MTF (Modulation Transfer Function) that is a modulation transfer function is a function that expresses as a spatial frequency characteristic how much the contrast of a subject is reproduced on the image plane. The vertical axis of the graphs shown in FIG. 6 and FIG. 7 indicates the MTF value representing the contrast. The horizontal axis shows the spatial frequency representing the resolution.

  6 and 7, curves C1 and C2 represent contrast characteristics at a certain image height, for example, an image height of 70%. The image height represents a distance from the center position of the image. An image height of 0% represents the center position of the image. An image height of 100% represents a position farthest from the center position in the image, that is, a corner position in a rectangle formed by the image.

  Furthermore, the curve C1 shows contrast characteristics in the sagittal direction. A curve C2 shows contrast characteristics in the tangential direction. The sagittal direction is a radial direction from the center position. The tangential direction is a concentric direction centered on the center position. N / 8, N / 4, and N / 2 are spatial frequencies that are 1/8 times, 1/4 times, and 1/2 times the Nyquist frequency, respectively.

  The graph shown in FIG. 6 represents the result of simulating the contrast characteristics when light is advanced from the opening 47 to the photoelectric conversion unit 49 without adjusting the light intensity distribution by the filter 42. FIG. 7 shows a result of simulating contrast characteristics when light having undergone adjustment of light intensity distribution by the filter 42 is advanced from the opening 47 to the photoelectric conversion unit 49.

  By making the light that has been adjusted by the filter 42 incident on the opening 47, light diffraction on the exit side of the opening 47 is suppressed compared to the case where light that has not been adjusted by the filter 42 is incident on the opening 47. The solid-state imaging device 5 according to the embodiment can reduce the generation of diffracted light by providing the filter 42 in the phase difference pixel 31.

  The contrast at each spatial frequency of N / 8, N / 4, and N / 2 is higher in the case of FIG. 7 than in the case of FIG. In the case of the embodiment shown in FIG. 7, since the diffracted light can be reduced, contrast characteristics can be improved as compared with the comparative example shown in FIG. Since the solid-state imaging device 5 can obtain a high-contrast image with the phase difference pixel 31, it is possible to perform accurate phase difference detection.

  The configuration of the filter 42 is not limited to that described in the embodiment, and may be changed as appropriate. The filter 42 may be provided with a stepped uneven surface instead of a curved surface. The filter 42 may be a gradation filter in which the density of black increases as the distance from the center increases. In this case, the filter 42 may have a flat plate shape with a constant thickness. The filter 42 may have any configuration capable of adjusting the transmittance distribution in the two-dimensional direction.

  According to the embodiment, the solid-state imaging device 5 is provided with a filter 42 as a light intensity adjusting unit on the incident side of the light shielding layer 46. The solid-state imaging device 5 can suppress light diffraction in the phase difference pixel 31 by adjusting the light intensity distribution in the filter 42. Since the solid-state imaging device 5 can reduce the generation of diffracted light in the phase difference pixel 31, it can perform highly accurate phase difference detection using the phase difference pixel 31. Thereby, the solid-state imaging device 5 has an effect that accurate focusing can be performed.

  Although the embodiment of the present invention has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  2 camera module, 5 solid-state imaging device, 6 imaging optical system, 10 AF driver, 20 pixel array, 30 imaging pixel, 31, 31R, 31L phase difference pixel, 40 microlens, 42 filter, 46 light shielding layer, 47 aperture, 49 Photoelectric conversion unit.

Claims (6)

A pixel array in which pixels including photoelectric conversion units are arranged in a matrix,
The pixel array includes a first pixel that is a pixel for detecting a subject image, and a second pixel that is a pixel for detecting a shift between the subject and the focus of the imaging optical system,
The second pixel is
A shielding unit having an opening that allows a part of the light traveling to the photoelectric conversion unit to pass through;
A solid-state imaging device comprising: a light intensity adjusting unit that is provided on an incident side of the shielding unit and adjusts a light intensity distribution in a two-dimensional direction. The second pixel includes a lens element that advances light to the photoelectric conversion unit,
The solid-state imaging device according to claim 1, wherein the light intensity adjustment unit is provided between the lens element and the shielding unit.   3. The solid-state imaging device according to claim 1, wherein the light intensity adjusting unit transmits light with a higher transmittance as it approaches a central axis passing through a center of the photoelectric conversion unit. The light intensity adjusting unit includes a filter containing a material that absorbs light,
The solid-state imaging device according to claim 3, wherein the filter is formed so as to increase in thickness in a direction perpendicular to the two-dimensional direction as the filter moves away from the central axis.   5. The solid-state imaging device according to claim 1, wherein the pixel array includes the second pixels in which the positions of the openings are different from each other. 6. An imaging optical system that captures light from the subject and forms a subject image;
Pixels including photoelectric conversion units are arranged in a matrix, and a pixel array that detects the subject image;
A focus adjustment unit that adjusts the focus of the imaging optical system based on a result of detecting a shift between the subject and the focus of the imaging optical system;
The pixel array includes a first pixel that is a pixel for detecting the subject image, and a second pixel that is a pixel for detecting the shift,
The second pixel is
A shielding unit having an opening that allows a part of the light traveling to the photoelectric conversion unit to pass through;
A camera module comprising: a light intensity adjusting unit that is provided on an incident side of the shielding unit and adjusts a light intensity distribution in a two-dimensional direction.

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