JP2012175144A - Imaging device, imaging apparatus, and manufacturing method of the imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device having a structure capable of accurately positioning and adhering a transparent plate on which a light shield mask is formed and an imaging device substrate, in a short time.SOLUTION: An imaging device 3 in which a transparent plate is adhered to an imaging device substrate on which a plurality of pixels are two-dimensionally arranged so as to position a pixel position, includes: a first light shield mask that transmits light of a first pupil area and a second light shield mask that transmits light of a second pupil area in a pupil division light-shielding mask area 13 on the transparent plate; and position detection light shield masks 38H and 38V, for positioning, arranged at, for example, predetermined positions outside the pupil division light-shielding mask area 13 so as to shield a plurality of pixels including a predetermined pixel while gradually changing a light-shielding area. A pair of the pixel and the first light shield mask structures a first focus detection pixel, and a pair of the pixel and the second light shield mask structures a second focus detection pixel, respectively.

Description

  The present invention relates to an image pickup device having a pixel having a focus detection function, an image pickup apparatus using the image pickup device, and a method for manufacturing the image pickup device.

  A phase difference detection method is known as a technique for detecting a shift amount from a focus position in an imaging apparatus. This phase difference detection method divides the light beam that has passed through the exit pupil of the imaging optical system into two parts, receives the divided light beam by the focus detection sensor, and the amount of deviation of the signal that is output according to the received light amount That is, the amount of focus shift of the imaging optical system is obtained by detecting the relative positional shift amount (phase difference) between the two images formed by the divided light beams.

  In order to detect such a phase difference using an image formed on the image sensor through the imaging optical system, an image sensor provided with a light-shielding portion for performing pupil division, and this image sensor were used. A phase difference detection method has been proposed. As such a proposal, for example, a technique described in Japanese Patent Application Laid-Open No. 2009-44535 can be cited. In this publication, in a semiconductor manufacturing process for manufacturing an image pickup device, a photodiode and a color constituting the image pickup device are described. It is described that a light shielding portion for pupil division is provided between the filter and the filter.

JP 2009-44535 A

  However, in the case of the configuration described in the above publication, development of a new dedicated image sensor is necessary, so that the development cost is significantly increased, and a semiconductor different from that for manufacturing a normal image sensor Since a manufacturing process is required, the manufacturing cost is also expensive. Furthermore, even after manufacturing, since it is necessary to distinguish between a normal image sensor and an image sensor with a focus detection function, the management cost increases.

  As a configuration for dealing with such a point, a transparent plate (for example, a glass plate) provided with a light-shielding mask that is a light-shielding portion for pupil division is used for an image sensor manufactured by a normal semiconductor manufacturing process. It is conceivable to manufacture an image sensor with a focus detection function by pasting. According to such a configuration, not only can the above-mentioned points be dealt with, but also a proven performance can be obtained because a proven imaging device can be used.

  In order to correctly obtain the information for phase difference detection from the pixel values of the image sensor having such a configuration, it is necessary to correctly dispose the light shielding mask on the pixel that has been previously positioned for phase difference detection. Therefore, it is necessary to accurately align the transparent plate provided with the light shielding mask with respect to a normal image sensor. In addition, in consideration of productivity, it is desirable that alignment can be performed in as short a time as possible.

  The present invention has been made in view of the above circumstances, and aligns a transparent plate provided with a light-shielding mask and an image sensor substrate on which a plurality of pixels are two-dimensionally arranged with high accuracy in a short time. It is an object of the present invention to provide an image pickup device having a structure that can be pasted, an image pickup apparatus using the image pickup device, and a method for manufacturing the image pickup device.

  In order to achieve the above object, the imaging device according to the first aspect of the present invention provides a semiconductor manufacturing process in which a plurality of pixels for photoelectrically converting an optical subject image are arranged two-dimensionally. An image pickup device substrate formed by the above-described image pickup device substrate, and a transparent plate pasted with the pixel position aligned with respect to the image pickup device substrate, wherein the plurality of pixels arranged on the image pickup device substrate are: A first pixel at a first predetermined position, a second pixel at a second predetermined position, and a third pixel at a third predetermined position, on the transparent plate, A first light-shielding mask provided so as to shield a portion decentered in one direction from the center of the first pixel when the transparent plate is attached to the image sensor substrate with the pixel position aligned; and The transparent plate is pasted on the transparent plate with the pixel position aligned with the image sensor substrate. A second light-shielding mask provided so as to shield a portion decentered in the other direction from the center of the second pixel, and the transparent plate on the image sensor substrate on the transparent plate. When affixed in position, a part of the plurality of pixels arranged on the image sensor substrate is shielded from light while gradually changing the light shielding area. A position-detecting light-shielding mask provided so that a specific position determined based on a change in area coincides with the third pixel, and the set of the first pixel and the first light-shielding mask Constitutes a first focus detection pixel, and a set of the second pixel and the second light shielding mask constitutes a second focus detection pixel.

  An imaging apparatus according to the second aspect of the present invention is formed by the above-described imaging device, an imaging optical system that forms a subject image on the imaging device, and an output from the first focus detection pixel. A phase difference detection unit that detects a phase difference between the first image and the second image formed by the output from the second focus detection pixel is provided.

  Furthermore, the manufacturing method of the imaging device according to the third aspect of the present invention is the above-described imaging device, wherein the imaging device substrate has a plurality of pixels arranged two-dimensionally along the horizontal direction and the vertical direction. The position detection shading mask is a horizontal position provided with a portion that gradually increases and a portion that gradually decreases the shading area for each of a plurality of pixels arranged in the horizontal direction. A detection light-shielding mask, and a vertical position detection light-shielding mask comprising a part for gradually increasing and a part for gradually decreasing the light-shielding area for each of a plurality of pixels arranged in the vertical direction. The specific position is a method for manufacturing an image pickup device in which a light-shielding area for each pixel is a position where a gradually increasing line and a gradually decreasing line intersect each other. Place the transparent plate on the substrate. And irradiating parallel light to the image pickup device substrate on which the transparent plate is arranged to perform the first image pickup by the image pickup device substrate, and the image signal obtained from the image pickup device substrate by the first image pickup. A first specific position where a shadow of the horizontal position detection light-shielding mask is formed, and a second specific position where the shadow of the vertical position detection light-shielding mask is formed; and The two third predetermined positions where the acquired straight line connecting the first specific position and the second specific position, the horizontal position detection light shielding mask, and the vertical position detection light shielding mask are to be arranged. A step of obtaining an inclination angle formed by a straight line connecting the two, a step of rotating the transparent plate with respect to the imaging element substrate so that the inclination angle is zero, and after the rotation of the transparent plate is completed Image sensor substrate Irradiating parallel light and performing second imaging with the imaging device substrate, and shading of the light shielding mask for horizontal position detection based on the image signal obtained from the imaging device substrate by the second imaging Obtaining the horizontal component of the first specific position where the first specific position is formed and the vertical component of the second specific position where the shadow of the vertical position detection light-shielding mask is formed; and A horizontal difference that is a difference between the horizontal component at the first specific position and the horizontal component at the third predetermined position where the light shielding mask for horizontal position detection is to be arranged, and the acquired first Calculating a vertical direction difference which is a difference between a vertical direction component at a specific position of 2 and a vertical direction component at the third predetermined position where the vertical position detection light-shielding mask is to be disposed; Above horizontal Translating the transparent plate with respect to the imaging device substrate so as to cancel the direction difference and the vertical direction difference.

  According to the image pickup device, the image pickup apparatus using the image pickup device, and the method for manufacturing the image pickup device of the present invention, the image pickup device substrate on which the transparent plate provided with the light shielding mask and the plurality of pixels are arranged in a two-dimensional manner Can be positioned and pasted with high accuracy in a short time.

1 is a front view showing a configuration of an image sensor in Embodiment 1 of the present invention. In the said Embodiment 1, the front view which shows the structure of the image pick-up element board | substrate with which the several pixel was arranged in two dimensions. FIG. 3 is a cross-sectional view taken along the line AA in FIG. The principal part front view which shows the structure of the transparent plate of the specific line part in which the light shielding mask was formed in the said Embodiment 1. FIG. FIG. 5 is a cross-sectional view taken along the line B-B in FIG. 4 showing the structure of the transparent plate in the specific line portion where the light shielding mask is formed in the first embodiment. FIG. 3 is a cross-sectional view illustrating a configuration of a photographic pixel and two types of focus detection pixels in the first embodiment. FIG. 3 is a diagram illustrating an arrangement of focus detection pixels provided on an image sensor in the first embodiment. FIG. 4 is a diagram illustrating an example of a shape of a position detection light-shielding mask according to the first embodiment. FIG. 3 is a diagram showing a positional relationship between a horizontal position detection light-shielding mask and focus detection pixels in the first embodiment. FIG. 2 is a block diagram illustrating a configuration of an image sensor manufacturing apparatus according to the first embodiment. In the said Embodiment 1, the figure which shows the example of the positional relationship of an image pick-up element board | substrate and a transparent board before performing position adjustment with the manufacturing apparatus of an image pick-up element. In the first embodiment, (A) a diagram illustrating an arrangement example when the transparent plate is not inclined with respect to the image sensor substrate, (B) a diagram illustrating a distribution of signal levels of a vertical direction addition signal, and (C) a horizontal direction addition. The diagram which shows distribution of the signal level of a signal. In the first embodiment, (A) a diagram illustrating an arrangement example when the transparent plate is inclined with respect to the image pickup device substrate, (B) a diagram illustrating a distribution of signal levels of a vertical direction addition signal, and (C) a horizontal direction addition. The diagram which shows distribution of the signal level of a signal. The figure for demonstrating the procedure which calculates | requires the X coordinate of the vertex of a V-shaped notch of the light shielding mask for horizontal direction position detection using the signal level graph of a vertical direction addition signal in the said Embodiment 1. FIG. 6 is a flowchart illustrating position adjustment processing by the imaging device manufacturing apparatus according to the first embodiment. 5 is a flowchart illustrating processing for acquiring a current position of a vertex of a V-shaped notch that is a specific position of a position detection light-shielding mask in the first embodiment. FIG. 2 is a block diagram illustrating a configuration of an imaging apparatus according to the first embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
[Embodiment 1]

  1 to 17 show the first embodiment of the present invention, and FIG. 1 is a front view showing the configuration of the image sensor 3.

  For example, the imaging element 3 is provided with a pupil division light shielding mask region 13 which is a region where focus detection pixels described later are arranged in a central rectangular portion excluding the peripheral portion. Here, most of the pupil division light shielding mask region 13 is a portion in which a plurality of imaging pixels 14 (see FIG. 6 and the like) are arranged in a two-dimensional manner. Focus detection pixels 13A and 13B (see FIG. 6 and the like) are arranged in pairs at several locations.

  Furthermore, in the peripheral part of the image sensor 3, for example, a horizontal position information area 15H which is a horizontally long rectangular area including a plurality of pixels, a vertical position information area 15V which is a vertically long rectangular area including a plurality of pixels, Is provided. In particular, in the example shown in FIG. 1, the horizontal position information area 15 </ b> H is provided at the upper left corner of the image sensor 3, and the vertical position information area 15 </ b> V is provided at the lower left corner of the image sensor 3.

  The image pickup device 3 includes an image pickup device substrate 3P formed by a semiconductor manufacturing process as shown in FIGS. 2 and 3 (the image pickup device substrate 3P has the same configuration as a normal image pickup device), and FIG. And the transparent plate 37 formed without depending on the semiconductor manufacturing process as shown in FIG. 5 has a configuration in which pixel positions are aligned (see FIG. 6).

  Then, after the transparent plate 37 is pasted with the pixel position aligned with the image pickup device substrate 3P, the horizontal position detection light-shielding mask 38H is provided in the vertical direction at a predetermined position in the horizontal position information area 15H. A vertical position detection light-shielding mask 38V is located at a predetermined position in the position information area 15V.

  2 is a front view showing the configuration of the image pickup device substrate 3P in which a plurality of pixels 14P are two-dimensionally arranged. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2 showing the structure of the pixels 14P on the image pickup device substrate 3P. FIG. 4 is a front view of the main part showing the configuration of the transparent plate 37 in the specific line portion where the light shielding masks 38A and 38B are formed, and FIG. 5 is the transparent plate 37 in the specific line portion where the light shielding masks 38A and 38B are formed. 4 is a cross-sectional view taken along the line B-B in FIG. 4, FIG. 6 is a cross-sectional view illustrating the configuration of the imaging pixel 14 and the two types of focus detection pixels 13 </ b> A and 13 </ b> B, and FIG. It is a figure which shows arrangement | positioning of pixel 13A, 13B.

  As shown in FIG. 2, the image pickup device substrate 3P has a plurality of pixels 14P for photoelectrically converting an optical subject image arranged in a two-dimensional matrix. In the example shown in FIG. They are arranged two-dimensionally along a row direction (or horizontal direction) and a direction perpendicular to the line direction (column direction or vertical direction).

  As shown in FIG. 3, each pixel 14P includes a photodiode 32 formed by doping impurities in the semiconductor substrate 31, wiring patterns 33 and 34 formed on the semiconductor substrate 31, a microlens 35, It has a laminated structure in which the photoelectric conversion layer PD, the wiring layer WL, and the microlens layer ML are formed from the deep portion toward the surface layer.

  The wiring patterns 33 and 34 have a light shielding function and have openings formed at positions corresponding to the photodiodes 32. In the configuration example shown in FIG. 3, the openings (and the microlens 35) provided in the wiring pattern 34 are provided. ) Defines the aperture ratio of the pixel 14P.

  Further, the microlens 35 is configured so that the center thereof is positioned on a vertical line (line indicated by a one-dot chain line) of the center of the photodiode 32.

  As shown in FIGS. 4 and 5, the transparent plate 37 is a transparent flat plate made of a material such as glass and provided with two types of light shielding masks 38A and 38B and a position detection light shielding mask. is there. Here, in the present embodiment, as described above, as the position detection light shielding mask, as described above, the horizontal position detection light shielding mask 38H for performing the horizontal position detection with high precision, and the vertical position detection with high precision. There are two types, a vertical position detection light-shielding mask 38V. However, the present invention is not limited to these two types, and a position detection light-shielding mask or the like for performing position detection in an oblique direction with high accuracy may be provided.

  In the example shown in FIG. 1, the horizontal position detection light shielding mask 38 </ b> H corresponds to the horizontal position information area 15 </ b> H provided in the upper left corner of the image sensor 3, and the upper left corner of the transparent plate 37. One vertical position detection light shielding mask 38 </ b> V is provided at the lower left corner of the transparent plate 37 corresponding to the vertical position information area 15 </ b> V provided at the lower left corner of the image sensor 3. ing.

  The horizontal position detection light-shielding mask 38H and the vertical direction position detection light-shielding mask 38V are, as will be described later, an angle shift amount when aligning the image pickup device substrate 3P and the transparent plate 37. In order to improve detection accuracy, it is desirable to provide the peripheral areas on the transparent plate 37 apart from each other. The arrangement shown in FIG. 1 is an example satisfying such a condition. However, the position detection light-shielding mask is not limited to being arranged as shown in FIG. 1, and is not limited to being provided one for each direction.

  The light shielding masks 38A and 38B and the position detection light shielding masks 38H and 38V are configured, for example, by depositing a black chrome film on the surface of the transparent plate 37 on the side facing the imaging element substrate 3P. Yes. In FIG. 4 and FIG. 9 to be described later, the range of each pixel is shown using a dotted line, but this dotted line is only described for explanation and does not exist on the actual transparent plate 37. Absent.

  Here, the first light-shielding mask 38A has a first predetermined position on the image pickup device substrate 3P when the transparent plate 37 is attached to the image pickup device substrate 3P with the pixel position aligned. The first pixel 14P located at the center of the first pixel 14P is shielded from light (see also FIG. 6). The set of the first pixel 14P and the first light shielding mask 38A constitutes the first focus detection pixel 13A shown in FIG. With such a configuration, the first focus detection pixel 13A includes the first focus detection pixel 13A in which the exit pupil of the imaging optical system 1 (see FIG. 17), which will be described later, is divided into two different pupil regions (that is, divided into pupils). In order to receive a light beam that has passed through one pupil region (here, the first pupil region is referred to as pupil A), hereinafter, it will be referred to as a pupil A focus detection pixel 13A or the like as appropriate. .

  In addition, the second light shielding mask 38B is placed on the transparent plate 37 at a second predetermined position on the image pickup device substrate 3P when the transparent plate 37 is attached to the image pickup device substrate 3P with the pixel position aligned. A portion eccentric from the center of a certain second pixel 14P in the other direction is shielded from light (see also FIG. 6). The set of the second pixel 14P and the second light shielding mask 38B constitutes the second focus detection pixel 13B shown in FIG. With such a configuration, the second focus detection pixel 13B has the first pupil in the exit pupil of the imaging optical system 1 (see FIG. 17), which will be described later, divided into two different pupil regions (that is, divided into pupils). In order to receive a light beam that has passed through two pupil regions (herein, the second pupil region is referred to as pupil B), it will be referred to as pupil B focus detection pixel 13B or the like as appropriate. .

  The imaging pixel 14 is configured by disposing only the transparent portion of the transparent plate 37 on the pixel 14P of the image sensor substrate 3P.

  Then, by pasting the transparent plate 37 on the image pickup device substrate 3P, the image pickup device 3 has a laminated structure in which a light shielding mask transparent plate layer MG is further provided as shown in FIG. As shown in FIG. 7, a group of pupil A focus detection pixels 13A and a group of pupil B focus detection pixels 13B are arranged in pairs.

  FIG. 8 is a diagram showing an example of the shape of the position detection light shielding mask 38H (substantially similarly, the position detection light shielding mask 38V).

  The position detection light-shielding masks 38H and 38V are formed on a plurality of pixels 14P arranged on the image pickup device substrate 3P when the transparent plate 37 is affixed to the image pickup device substrate 3P on the transparent plate 37. Among them, some of the plurality of pixels 14P are provided so as to be shielded from light while gradually varying the light shielding area. Then, a specific position (an example will be described below) determined based on a change in the light shielding area in the position detection light shielding masks 38H and 38V is described in the third pixel 14P at a third predetermined position on the image sensor substrate 3P. It is provided to match.

  Specifically, the horizontal position detection light-shielding mask 38H includes a part that gradually increases and a part that gradually decreases the light-shielding area of the plurality of pixels 14P arranged in the horizontal direction. As shown in the figure, a rectangular shading mask whose vertical direction is the short direction of the pixel width and whose horizontal direction is the longitudinal direction extending over a plurality of pixels is cut into a V shape so that the center part is constricted It has become. Accordingly, the horizontal position detecting light-shielding mask 38H can be disposed only on one horizontal line so as not to extend over a plurality of horizontal lines.

  In a similar manner, the vertical position detection light-shielding mask 38V includes a part that gradually increases and a part that gradually decreases the light-shielding area of the plurality of pixels 14P arranged in the vertical direction. The shape shown is a vertical shape. Therefore, the vertical position detection light-shielding mask 38V can be arranged only on one vertical line so as not to extend over a plurality of vertical lines.

  The position detection light-shielding masks 38H and 38V are, for example, positions where the light-shielding area for each pixel crosses a gradually increasing line and a gradually decreasing line, that is, the vertex 38Hc of the V-shaped notch in FIG. (See also FIG. 9) is the specific position.

  FIG. 9 is a diagram illustrating a positional relationship between the horizontal position detection light-shielding mask 38H and the focus detection pixel 13A.

  The vertex 38Hc, which is a specific position of the position detection light-shielding masks 38H and 38V when the transparent plate 37 is pasted on the image pickup device substrate 3P with the pixel positions aligned, corresponds to the focus detection pixels 13A, It is arranged so as to have a predetermined positional relationship with respect to 13B. In the example shown in FIG. 9, the focus detection pixel in the pupil division light shielding mask region 13 that is closest to the third pixel 14P (that is, the horizontal position detection light shielding mask 38H after alignment here). Here, the vertex 38Hc of the V-shaped notch is arranged with respect to the center of the pupil A focus detection pixel 13A so as to separate the distance Oh in the horizontal direction and the distance Ov in the vertical direction. Here, the distance Oh is an integer multiple of the pixel pitch in the horizontal direction, and the distance Ov is an integer multiple of the pixel pitch in the vertical direction.

  Next, FIG. 10 is a block diagram showing a configuration of an imaging device manufacturing apparatus.

  The image pickup device manufacturing process performed by the configuration of FIG. 10 includes an image pickup device substrate 3P for which the semiconductor manufacturing process has been completed, a transparent plate 37 on which light blocking masks 38A and 38B and position detection light blocking masks 38H and 38V have already been formed, The image pickup device manufacturing apparatus shown in FIG. 10 can be said to be a bonding adjustment apparatus.

  The image sensor manufacturing apparatus includes a collimator light source 21, a transparent plate moving device 22, an image sensor drive unit 23, a position information region separation timing decoder 24, a coordinate calculation unit 25, a deviation amount calculation unit 26, and a scanning. And a control circuit 27, and a transparent plate 37 and an image pickup device substrate 3P to be manufactured are attached to the control circuit 27.

  The collimator light source 21 irradiates the image pickup device substrate 3P with collimator light, which is parallel light, via the transparent plate 37.

  The transparent plate moving device 22 is a device that holds the transparent plate 37 by the pickup unit, and moves or rotates the held transparent plate 37 in parallel. Here, the pickup unit attracts and holds the transparent plate 37 by suction with a vacuum pump, for example, and opens the transparent plate 37 by stopping the suction.

  The image sensor driving unit 23 outputs the horizontal synchronization signal HD and the vertical synchronization signal VD to the image sensor substrate 3P functioning as a normal image sensor, and outputs a plurality of pixels 14P arranged on the image sensor substrate 3P to a predetermined level. Drive in order. Therefore, the image signal is output from the image pickup device substrate 3P as an image signal (pixel data) in pixel units in the order of the read pixels. Further, the image sensor driving unit 23 reads out position information that is information on the pixel position read from the image sensor substrate 3P based on the horizontal synchronization signal HD and the vertical synchronization signal VD output to the image sensor substrate 3P. Is output to the position information region separation timing decoder 24, and a calculation timing signal is output to the coordinate calculation unit 25. Here, the read position information is, for example, a pulse signal having a predetermined timing corresponding to the positions of the plurality of pixels 14P arranged in a matrix.

  Based on the read position information from the image sensor driving unit 23, the position information area separation timing decoder 24 includes the pixels 14P at the read position included in the position information areas 15H and 15V (the position information areas 15H and 15V include A position information area instruction signal that is a signal indicating that the position detection light-shielding masks 38H and 38V are located at a third predetermined position where the position detection light-shielding masks 38H and 38V are to be located) This is a circuit for outputting to the unit 25. That is, the position information area separation timing decoder 24 includes, for example, a counter that counts pulse signals of read position information and a storage unit that holds values corresponding to the positions of all the pixels 14P included in the position information areas 15H and 15V. The position information area instruction signal is output when the count value reaches a predetermined value (that is, a value corresponding to the position of the pixel 14P included in the position information areas 15H and 15V).

  When the position information area instruction signal is input from the position information area separation timing decoder 24, the coordinate calculation unit 25 identifies that the image signal input from the image sensor substrate 3P is a signal of the position information pixel 14P, The pixel data is stored in an internal buffer (not shown). Thereafter, when receiving a calculation timing signal from the image sensor driving unit 23, the coordinate calculation unit 25 identifies that data of all the pixels 14P in the horizontal position information area 15H or the vertical position information area 15V is accumulated in the buffer. As will be described later, the transparent plate 37 is aligned with an accuracy of, for example, several tens of microns with respect to the image pickup device substrate 3P at the initial stage. The positions of the position information areas 15H and 15 and the size of the areas are set so that the shadows of the light shielding masks 38H and 38V are almost certainly projected into the position information areas 15H and 15V. Therefore, it can be expected that the shadows of the position detection light shielding masks 38H and 38V are projected in the position information areas 15H and 15V. Then, the coordinate calculation unit 25 calculates the shadow coordinates of the vertex 38Hc of the V-shaped notch of the position detection light-shielding masks 38H and 38V by performing calculations as described later, and the calculated coordinates are used as the shift amount calculation unit 26. Output to.

  The deviation amount calculation unit 26 calculates the shaded coordinates of the vertex 38Hc of the V-shaped notch of the horizontal position detection light-shielding mask 38H and the V-shaped notch of the vertical position detection light-shielding mask 38V obtained by the coordinate calculation unit 25. Based on the coordinates of the shadow of the vertex 38Hc and the coordinates of the third pixel 14P on which the shadow of the vertex 38Hc is to be projected, the transparent plate 37 is moved with respect to the image sensor substrate 3P as described later. The power scanning direction (parallel movement direction, rotational movement direction, etc.) and scanning amount (parallel movement amount, rotational movement amount, etc.) are determined.

  The scanning control circuit 27 controls the transparent plate moving device 22 based on the scanning direction and the scanning amount determined by the deviation amount calculation unit 26, and changes the two-dimensional position of the transparent plate 37 with respect to the imaging element substrate 3P. Scanning is performed.

  Next, FIG. 11 is a diagram illustrating an example of a positional relationship between the imaging element substrate 3P and the transparent plate 37 before the position adjustment is performed by the imaging element manufacturing apparatus.

  As described above, before the position adjustment is performed by the imaging device manufacturing apparatus, the transparent plate 37 is aligned with an accuracy of, for example, several tens of microns with respect to the imaging device substrate 3P while observing with an observation camera or the like. It shall be. Therefore, even if this initial alignment error is taken into account, if the collimator light is irradiated in this state, the shadows of the position detection light shielding masks 38H and 38V are projected into the position information areas 15H and 15V. .

  In this initial state, it is generally considered that the transparent plate 37 is displaced in the horizontal and vertical directions with respect to the image pickup device substrate 3P and is also displaced in the rotational direction.

  Under such a premise, the position is adjusted by the imaging device manufacturing apparatus. FIG. 15 is a flowchart showing a position adjustment process performed by the imaging device manufacturing apparatus.

  When this processing is started, first, the shaded coordinates of the vertex 38Hc of the V-shaped notch of the horizontal position detection light shielding mask 38H, that is, the coordinates (Xc1, Yc1) of the first specific position, and the vertical position detection light shielding mask. The shaded coordinates of the vertex 38Hc of the V-shaped notch of 38V, that is, (Xc2, Yc2) of the second specific position are obtained (step S1). Details of this processing will be described with reference to FIG.

  FIG. 16 is a flowchart showing a process of acquiring the current position of the V-shaped notch vertex 38Hc, which is a specific position of the position detection light-shielding masks 38H and 38V.

  When this processing is started, collimator light is irradiated from the collimator light source 21 to the image pickup device substrate 3P on which the transparent plate 37 is arranged. Then, under the control of the image sensor driving unit 23, the image sensor substrate 3P is exposed (first imaging), and the image signal is read (step S11).

  Reading of the image signal from the image pickup device substrate 3P is sequentially performed in units of pixels as described above. Therefore, the coordinate calculation unit 25 first accumulates pixel data of all the pixels 14P included in the horizontal position information area 15H based on the position information area instruction signal from the position information area separation timing decoder 24. Thereby, the image data of the horizontal direction position information area 15H is extracted (step S12). After the extraction of the image data in the horizontal position information area 15H is completed, a calculation timing signal from the image sensor driving unit 23 is input to the coordinate calculation unit 25, and the following steps S13 to S19 are performed.

  Then, first, each pixel data in the horizontal position information area 15H, which is a horizontally long rectangular area including a plurality of pixels 14P, is added in the vertical direction and the horizontal direction (step S13).

  12A is a diagram illustrating an arrangement example when the transparent plate 37 is not inclined with respect to the image pickup device substrate 3P, FIG. 12B is a diagram illustrating a distribution of signal levels of the vertical direction addition signal, and FIG. 12C is a horizontal diagram. It is a diagram which shows distribution of the signal level of a direction addition signal.

  Since the horizontal position detection light-shielding mask 38H shields incident light, the signal level output from the pixel 14P decreases as the shadow area increases. Accordingly, as the horizontal position detection light-shielding mask 38H is formed in a shape having a V-shaped cutout, the signal level distribution of the vertical direction addition signal is approximately 2 as shown in FIG. It is a mountain shape that forms an equilateral triangle. In addition, as shown in FIG. 12C, the distribution of the signal level of the horizontal direction addition signal is such that the addition signal of the horizontal line in which the horizontal position detection light-shielding mask 38H is arranged in the largest area has a minimum value. It becomes nagata.

  Next, FIG. 13A is a diagram illustrating an arrangement example when the transparent plate 37 is inclined with respect to the image pickup device substrate 3P, FIG. 13B is a diagram illustrating a distribution of signal levels of the vertical direction addition signal, and FIG. 13C is horizontal. It is a diagram which shows distribution of the signal level of a direction addition signal.

  When the inclination of the transparent plate 37 is relatively small as shown in FIG. 13A, the distribution of the signal level of the vertical direction addition signal is a mountain shape having a substantially isosceles triangle shape shown in FIG. The waveform has a similar shape. On the other hand, the distribution of the signal level of the horizontal direction addition signal is a waveform in which the amplitude of the peaks and valleys is reduced in the valley-shaped waveform shown in FIG.

  Therefore, the horizontal position (X coordinate) of the vertex 38Hc of the V-shaped notch, which is the specific position of the horizontal position detection light-shielding mask 38H, can be obtained stably regardless of the presence or absence of a relatively small inclination. I understand that. Similarly, the vertical position (Y coordinate) of the vertex 38Hc of the V-shaped notch, which is the specific position of the vertical position detection light-shielding mask 38V, can be obtained stably regardless of the presence or absence of a relatively small inclination. is there.

  FIG. 14 is a diagram for explaining a procedure for obtaining the X coordinate of the vertex 38Hc of the V-shaped notch of the horizontal position detection light-shielding mask 38H using the signal level graph of the vertical direction addition signal.

  For the vertical direction addition signal calculated by the processing in step S13 described above, first, a local maximum value is detected, and the X coordinate XDpn of the vertical line that gives this local maximum value is obtained (step S14). The X coordinate XDpn obtained here is a coordinate value with the pixel pitch in the horizontal direction as a unit.

  Next, with respect to the vertical direction addition signal, the largest value on the left side of the local maximum value excluding the local maximum value and the next largest value after the local maximum value (hereinafter referred to as the second local maximum value) The next largest values (hereinafter referred to as quasi-maximum values) Dlmax1 and Dlmax2 are extracted, and on the right side of the maximal values, the largest value and the next largest value (as described above, quasi-maximum values). ) Extract Drmax1 and Drmax2 (step S15).

  In the signal level graph of the vertical direction addition signal as shown in FIG. 14, the straight line L1 passing through the two quasi-maximum values Dlmax1 and Dlmax2 on the left side, and the two quasi-maximum values Drmax1 on the right side and the quasi-maximum values Each straight line L2 passing through the maximum value Drmax2 is obtained as a linear function (step S16).

  Subsequently, an intersection point between the straight line L1 and the straight line L2 is obtained, and an X coordinate distance XDpsub between the obtained intersection point and the maximum value of the X coordinate XDpn described above is obtained (step S17).

  Thereafter, XDpn and XDpsub are added to obtain the X coordinate Xc1 of the intersection of the straight line L1 and the straight line L2, which is the first specific position (step S18).

  Next, in the horizontal direction addition signal as shown in FIG. 13C calculated by the processing in step S13 described above, the Y coordinate position that gives the minimum value is obtained, and the obtained Y coordinate position is set to the first value. It is set as the Y coordinate Yc1 of the specific position (step S19).

  By such processing, the coordinates (Xc1, Yc1) of the first specific position shown in FIG. 11 were obtained. Subsequently, by performing the same processing, the coordinates (Xc2, Yc2) of the second specific position shown in FIG. 11 are obtained.

  That is, based on the position information area instruction signal from the position information area separation timing decoder 24, the coordinate calculation unit 25 first accumulates pixel data of all the pixels 14P included in the vertical direction position information area 15V. Thereby, the image data of the vertical position information area 15V is extracted (step S20). After the extraction of the image data in the vertical position information area 15V is completed, a calculation timing signal from the image sensor driving unit 23 is input to the coordinate calculation unit 25, and the following steps S21 to S27 are performed.

  Then, each pixel data in the vertical position information area 15V, which is a vertically long rectangular area including the plurality of pixels 14P, is added in the horizontal direction and the vertical direction (step S21).

  For the horizontal direction addition signal calculated by the processing of step S21, first, a local maximum value is detected, and a Y coordinate YDpn of a horizontal line that gives this local maximum value is obtained (step S22). The Y coordinate YDpn obtained here is a coordinate value with the pixel pitch in the vertical direction as a unit.

  Next, with respect to the horizontal direction addition signal, the largest value and the next largest value (quasi-maximal value) on the upper side of the maximum value excluding the maximum value and the next largest value (second maximum value) after the maximum value. Value) Dumax1 and Dumax2 are extracted, and the largest value and the next largest value (quasi-maximum values) Ddmax1 and Ddmax2 are extracted below the maximum values (step S23).

  Then, in the signal level graph of the horizontal direction addition signal, a straight line L3 passing through the upper two quasi-maximum values Dumax1 and quasi-maximum value Dumax2, and two lower quasi-maximum values Ddmax1 and Ddmax2 are obtained. Each passing line L4 is obtained as a linear function (step S24).

  Subsequently, an intersection between the straight line L3 and the straight line L4 is obtained, and a Y coordinate distance YDpsub between the obtained intersection and the maximum value of the Y coordinate YDpn described above is obtained (step S25).

  Thereafter, YDpn and YDpsub are added to obtain the Y coordinate Yc2 of the intersection of the straight line L3 and the straight line L4 as the second specific position (step S26).

  Next, in the vertical direction addition signal calculated by the process of step S21 described above, an X coordinate position that gives a minimum value is obtained, and the obtained X coordinate position is set as the X coordinate Xc2 of the second specific position. (Step S27).

  When the coordinates (Xc2, Yc2) of the second specific position shown in FIG. 11 are obtained by such processing, the processing returns to the processing shown in FIG.

  In the above description, the coordinates of the specific position are obtained as the intersections of the straight lines obtained by the left and right or the upper and lower two quasi-maximal values. However, the present invention is not limited to this. The accuracy can be further improved by obtaining the regression line and obtaining the coordinates of the specific position as the intersection of the regression lines.

  Further, in the case of the single-plate image pickup device substrate 3P in which the color filter array is arranged, even if the surface brightness of the collimator light is constant, the signal level output from the pixel 14P differs depending on the color. Therefore, the calculation as described above cannot be performed accurately as it is. Therefore, the above-described calculation may be performed only for the same color pixels 14P in the position information areas 15H and 15V, or the sensitivity characteristic for each color becomes substantially the same by performing spectral sensitivity correction. The data of all the pixels 14P in the position information areas 15H and 15V may be corrected so that the data can be used.

  Returning to the description of FIG. 15, the coordinates of the target arrangement position (position of the third pixel 14P) where the V-shaped notch vertex 38Hc of the horizontal position detection light-shielding mask 38H is to be arranged are as shown in FIG. (X1, Y1), and the coordinates of the target arrangement position (the position of the third pixel 14P) where the V-shaped notch vertex 38Hc of the vertical position detection light-shielding mask 38V is to be arranged are (X1, Y2). These have the same X-coordinate and differ only in the Y-coordinate. Therefore, first, the inclination angle θ of the transparent plate 37 with respect to the image pickup device substrate 3P is obtained so that the X coordinate of the first specific position matches the X coordinate of the second specific position.

  For this reason, the deviation amount calculation unit 26 uses the coordinates (Xc1, Yc1) of the first specific position and the coordinates (Xc2, Yc2) of the second specific position obtained by the coordinate calculation unit 25 by the above-described processing. Using these, the difference (Xa, Ya) is calculated by (Xc2-Xc1, Yc2-Yc1) (step S2).

  Next, the deviation amount calculation unit 26 calculates the inverse tangent (arc tangent) of Xa / Ya to obtain the inclination angle θ of the transparent plate 37 with respect to the image sensor substrate 3P (step S3).

  In step S2 and step S3, the inclination angle θ is obtained by using a mathematical formula, but the present invention is not limited to this. For example, the inclination angle θ may be obtained by referring to a table.

  Subsequently, the scanning control circuit 27 controls the transparent plate moving device 22 to rotate the transparent plate 37 by an amount that cancels the tilt angle θ obtained by the deviation amount calculation unit 26 (that is, −θ). (Step S4).

  When the transparent plate 37 is rotated, the image pickup device substrate 3P is exposed to light (second image pickup) based on the image signal read out in substantially the same manner as the processing in step S1 described with reference to FIG. The shaded coordinates of the vertex 38Hc of the V-shaped notch of the horizontal position detecting light shielding mask 38H, that is, the coordinates (Xc1 ′, Yc1 ′) of the first specific position, and the V-shaped notched of the vertical position detecting light shielding mask 38V. The coordinates of the shadow of the vertex 38Hc, that is, (Xc2 ′, Yc2 ′) of the second specific position are obtained (step S5).

  Here, it is assumed that the processing shown in FIG. 16 is performed, but in the following processing, the Y coordinate Yc1 ′ of the first specific position and the X coordinate Xc2 ′ of the second specific position are not necessarily obtained. In order not to use, the process which calculates | requires these coordinates (namely, each process of step S19 in FIG. 16 and step S27) may be abbreviate | omitted. That is, at least the X coordinate Xc1 'that is the horizontal component of the first specific position and the Y coordinate Yc2' that is the vertical component of the second specific position may be obtained.

  However, if the tilt angle θ is corrected by the process of step S4 described above, the X coordinate Xc1 ′ of the first specific position and the X coordinate Xc2 ′ of the second specific position should match. In order to verify the result, the X coordinate Xc2 ′ of the second specific position may be obtained. If a verification result that matches the X coordinate cannot be obtained, the Y coordinate Yc1 ′ of the first specific position is also obtained, and the acquired current positions (Xc1 ′, Yc1 ′) and (Xc2 ′, Yc2) are obtained. The above-described steps S2 to S4 may be repeated based on ').

  Next, an X coordinate difference ΔX, which is a horizontal difference between the coordinates (Xc1 ′, Yc1 ′) of the current first specific position and the target arrangement position (X1, Y1), is obtained as Xc1′−X1, and the current A Y coordinate difference ΔY that is a vertical difference between the coordinates (Xc2 ′, Yc2 ′) of the second specific position and the target arrangement position (X1, Y2) is obtained as Yc2′−Y2 (step S6).

  Then, the transparent plate 37 is translated by an amount that cancels the difference (ΔX, ΔY) (ie, (−ΔX, −ΔY)) (step S7).

  When the alignment between the transparent plate 37 and the image pickup device substrate 3P is completed in this way, thereafter, the image pickup device substrate 3P and the transparent plate 37 are fixed using, for example, an adhesive, and suction by the vacuum pump of the pickup unit is stopped. Then, the transparent plate 37 is removed from the transparent plate moving device 22.

  As a result, the imaging device 3 in which the focus detection pixel functions correctly at a predetermined pixel position is manufactured, and thus this processing is terminated.

  Next, FIG. 17 is a block diagram illustrating a configuration of the imaging apparatus.

  The imaging apparatus of the present embodiment to which the imaging element 3 manufactured as described above is applied is configured as a digital camera having an AF function, for example, and as shown in FIG. An imaging unit 2, a phase difference detection unit 6, a focus control unit 7, an image processing unit 10, and an interpolation unit 11.

  The imaging optical system 1 is an objective optical system for forming an optical subject image on the image sensor 3 in the imaging unit 2, and includes an optical diaphragm (not shown) and a focus lens for adjusting the focal position. It is configured to include.

  The imaging unit 2 includes the above-described imaging element 3, imaging element driving unit 4, and pixel type signal output unit 5.

  The image sensor driving unit 4 controls driving of the image sensor 3. That is, the image sensor driving unit 4 outputs the horizontal synchronization signal HD and the vertical synchronization signal VD to the image sensor 3, and drives a plurality of pixels arranged on the image sensor 3 as described above in a predetermined order. It is supposed to be. Accordingly, the image signal is output from the image sensor 3 as an image signal (pixel data) in pixel units in the order of the read pixels. Further, the image sensor driving unit 4 outputs read position information, which is information on the pixel position read from the image sensor 3, based on the horizontal synchronization signal HD and the vertical synchronization signal VD output to the image sensor 3. While outputting to the classification signal output part 5, the correlation timing signal which shows the timing which performs a correlation calculation is output to the phase difference detection part 6. FIG.

  Here, the read position information output from the image sensor driving unit 4 to the pixel type signal output unit 5 is, for example, a pulse signal having a predetermined timing corresponding to the positions of a plurality of pixels arranged in a matrix. .

  Further, the image sensor driving unit 4 outputs the control signals (vertical synchronization signal, horizontal synchronization signal, readout position information, correlation timing signal) as described above in synchronization with the operation of a release button (not shown). It has become.

  The pixel type signal output unit 5 generates a pixel type signal indicating the type of the image signal sequentially output from the image sensor 3 in units of pixels based on the read position information from the image sensor drive unit 4, and the phase difference detector 6 is a circuit that outputs the data to 6.

  Here, the pixel type signal includes a focus detection pixel signal (including a position information pixel signal described below) and a pupil type signal. The former focus detection pixel signal is a signal of pixel data (hereinafter referred to as position information pixel) in which the pixel data output from the image sensor 3 is located at the focus detection pixels 13A and 13B or the position detection light-shielding masks 38H and 38V. It is a signal which shows that it is. In the latter pupil type signal, pixel data output from the image sensor 3 is from any of the pupil A focus detection pixel 13A and the pupil B focus detection pixel 13B among the focus detection pixels. It is a signal which shows.

  The pixel type signal output unit 5 includes, for example, a counter that counts pulse signals of readout position information, and a storage unit that holds values corresponding to the positions of the focus detection pixels 13A and 13B and the position information pixels described above. Configured. Then, the pixel type signal output unit 5 outputs a focus detection pixel signal (also serves as a position information pixel signal) when the count value reaches a predetermined value corresponding to the position of the focus detection pixels 13A and 13B or the position information pixel. Output. Furthermore, the pixel type signal output unit 5 further outputs a pupil type signal when the count value is a predetermined value corresponding to the positions of the focus detection pixels 13A and 13B.

  Therefore, neither the focus detection pixel signal nor the pupil type signal is output when the image signal output from the image pickup device 3 is a signal of the photographing pixel 14, and the focus signal when the image signal is a signal of the position information pixel. Although the detection pixel signal is output but the pupil type signal is not output, both the focus detection pixel signal and the pupil type signal are output when the signals are the focus detection pixels 13A and 13B.

  Further, the pixel type signal output unit 5 outputs the focus detection pixel signal to the interpolation unit 11 as well.

  The phase difference detection unit 6 is based on the image signal from the image sensor 3, the pixel type signal from the pixel type signal output unit 5, and the correlation timing signal from the image sensor drive unit 4. The subject image (first image formed by the output from the first pixel group) and the subject image (second image) formed on the image signal from the pupil B focus detection pixel 13B And a second image formed by output from the pixel group), and a detection result is output to the focus control unit 7 as a phase difference signal.

  The focus control unit 7 includes a defocus amount calculation unit 8 and a focus lens drive unit 9, and drives the imaging optical system 1 so that the phase difference detected by the phase difference detection unit 6 approaches 0. It is.

  That is, the defocus amount calculation unit 8 calculates the defocus amount based on the phase difference signal from the phase difference detection unit 6 and outputs the defocus amount to the focus lens drive unit 9.

  The focus lens driving unit 9 is provided in the imaging optical system 1 so that the subject image formed on the image sensor 3 is in focus according to the defocus amount calculated by the defocus amount calculation unit 8. Drive the focus lens. Thereby, the AF function of the imaging apparatus is realized. The imaging apparatus is provided with an operation unit (not shown) (for example, a release button of a digital camera). When an execution signal is instructed by an operation signal from the operation unit, focus detection is performed at the time of execution. The AF function is executed.

  The interpolation unit 11 performs focus detection pixels based on a focus detection pixel signal (also serving as a position information pixel signal) from the pixel type signal output unit 5 with respect to an image pickup signal from the image pickup device 3 obtained by execution of shooting processing. 13A and 13B and position information pixels are interpolated. That is, since the focus detection pixels 13A and 13B and the position information pixel cannot be used as shooting pixels, the interpolation unit 11 uses the pixel data at the positions of the focus detection pixels 13A and 13B and the position information pixel. A process of generating by interpolation using pixel data of surrounding photographing pixels 14 is performed.

  The image processing unit 10 performs image processing on the image signal interpolated by the interpolation unit 11. The image data generated by the image processing unit 10 is recorded on a recording medium (not shown) or displayed on a display device (not shown).

  In the above description, the position detection light shielding masks 38H and 38V are provided on the surface of the transparent plate 37 on the side facing the image pickup device substrate 3P. Instead, the position detection light shielding masks H and 38V are provided on the transparent plate 37. The position information pixel can be used again as the photographic pixel 14 if it is provided on the surface opposite to the surface facing the image pickup device substrate 3P and is formed so as to be erasable after being positioned and attached. There is an advantage that the interpolation of the position information pixels by the interpolation unit 11 is not required.

  According to the first embodiment, the position detection light shielding masks 38H and 38V having a predetermined positional relationship with respect to the light shielding masks 38A and 38B are provided, and the position detection light shielding masks 38H and 38V should be located. By aligning the position detection light shielding masks 38H and 38V on the third pixel 14P, the light shielding masks on the first and second pixels 14P on which the light shielding masks 38A and 38B are to be positioned. 38A and 38B can be aligned with high accuracy in a short time.

  Further, since the position detection light-shielding masks 38H and 38V are configured to include a part for gradually increasing and a part for gradually decreasing the light-shielding area for each pixel, the light-shielding area for each pixel gradually increases. The specific position is obtained as a position where the increasing line and the gradually decreasing line intersect (and hence the position where the output value from the pixel gradually decreases and the gradually increasing line intersects). There is an advantage that calculation is easy.

  In particular, it is possible to specify the horizontal direction by providing a horizontal position detection light-shielding mask 38H provided with a part for gradually increasing and a part for gradually reducing the light-shielding area of the plurality of pixels 14P arranged in the horizontal direction. The position can be obtained with high accuracy. Further, by providing a vertical position detection light-shielding mask 38 </ b> V provided with a part for gradually increasing and a part for gradually decreasing the light-shielding area of the plurality of pixels 14 </ b> P arranged in the vertical direction, the vertical direction is specified. The position can be obtained with high accuracy. Such a configuration is particularly effective for the image sensor substrate 3P in which the plurality of pixels 14P are two-dimensionally arranged along the horizontal direction and the vertical direction.

  Further, by providing the position detection light-shielding masks 38H and 38V in the peripheral area on the transparent plate 37, it is possible to prevent the deterioration of the image quality of the main subject that is often located at the center of the image. In addition, by providing the horizontal position detecting light shielding mask 38H and the vertical position detecting light shielding mask 38V on the transparent plate 37, the alignment accuracy can be improved.

  When the position detection light-shielding masks 38H and 38V are provided on the surface of the transparent plate 37 opposite to the surface to be attached to the imaging element substrate 3P and are erased after alignment, the position detection light-shielding masks are used. There is an advantage that image quality is not deteriorated at all by the masks 38H and 38V.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, you may delete some components from all the components shown by embodiment. Furthermore, the constituent elements over different embodiments may be appropriately combined. Thus, it goes without saying that various modifications and applications are possible without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1 ... Imaging optical system 2 ... Imaging part 3 ... Imaging element 3P ... Imaging element board | substrate 4 ... Imaging element drive part 5 ... Pixel type signal output part 6 ... Phase difference detection part 7 ... Focus control part 8 ... Defocus amount calculation part DESCRIPTION OF SYMBOLS 9 ... Focus lens drive part 10 ... Image processing part 11 ... Interpolation part 13 ... Shading mask area | region for pupil division 13A ... Pupil A focus detection pixel (1st focus detection pixel)
13B ... Pupil B focus detection pixel (second focus detection pixel)
DESCRIPTION OF SYMBOLS 14 ... Shooting pixel 14P ... Pixel 15H ... Horizontal direction position information area 15V ... Vertical direction position information area 21 ... Collimator light source 22 ... Transparent plate moving device 23 ... Imaging element drive part 24 ... Position information area separation timing decoder 25 ... Coordinate calculation part 26 ... Deviation amount calculation unit 27 ... Scanning control circuit 31 ... Semiconductor substrate 32 ... Photodiode 33, 34 ... Wiring pattern 35 ... Micro lens 37 ... Transparent plate 38A ... First light shielding mask 38B ... Second light shielding mask 38H ... Horizontal Direction position detection shading mask 38Hc... Vertex (specific position)
38V: Shading mask for vertical position detection

Claims (8)

An image sensor substrate formed by a semiconductor manufacturing process so that a plurality of pixels for photoelectrically converting an optical subject image are arranged in a two-dimensional manner;
A transparent plate pasted with the pixel position aligned with the image sensor substrate;
An imaging device comprising:
The plurality of pixels arranged on the image sensor substrate include a first pixel at a first predetermined position, a second pixel at a second predetermined position, and a third pixel at a third predetermined position. And including
On the transparent plate, when the transparent plate is attached to the image pickup device substrate with the pixel position aligned, the transparent plate is provided so as to shield a portion eccentric from the center of the first pixel in one direction. 1 shading mask;
On the transparent plate, when the transparent plate is attached to the image pickup device substrate with the pixel position aligned, the second plate is provided so as to shield a portion eccentric from the center of the second pixel in the other direction. Two shading masks;
On the transparent plate, when the transparent plate is affixed to the image sensor substrate with the pixel position aligned, some of the plurality of pixels arranged in the image sensor substrate are A position-detecting light-shielding mask provided so as to shield light while gradually changing the light-shielding area, and provided so that a specific position determined based on a change in the light-shielding area coincides with the third pixel;
Further comprising
The set of the first pixel and the first shading mask constitutes a first focus detection pixel, and the set of the second pixel and the second shading mask constitutes a second focus detection pixel. An image sensor characterized by the above. The position detection light-shielding mask includes a part that gradually increases a light-shielding area for each pixel and a part that gradually decreases,
The imaging device according to claim 1, wherein the specific position is a position where a line where a light shielding area for each pixel gradually increases and a line where the light shielding area gradually decreases intersect. The image pickup device substrate has a plurality of pixels arranged two-dimensionally along the horizontal direction and the vertical direction.
The position detection light-shielding mask includes a horizontal position detection light-shielding mask including a portion that gradually increases and a portion that gradually decreases the light-shielding area of a plurality of pixels arranged in the horizontal direction, and a vertical direction. 3. The vertical position detection light-shielding mask, comprising: a part that gradually increases a light-shielding area of a plurality of pixels arranged in a plurality of pixels; and a part that gradually decreases a light-shielding area. Image sensor.   4. The image pickup device according to claim 3, wherein the horizontal position detecting light shielding mask and the vertical position detecting light shielding mask are provided apart from each other in a peripheral region on the transparent plate. .   2. The position detecting light-shielding mask is provided erasable on a surface of the transparent plate opposite to a surface to be attached to the imaging element substrate. Item 5. The imaging device according to any one of Items 4 to 4. The image sensor according to claim 1,
An imaging optical system for forming a subject image on the image sensor;
A phase difference detection unit that detects a phase difference between the first image formed by the output from the first focus detection pixel and the second image formed by the output from the second focus detection pixel. When,
An imaging apparatus comprising: The imaging optical system can adjust the focal position,
The imaging apparatus according to claim 6, further comprising a focus control unit that drives the imaging optical system so that the phase difference detected by the phase difference detection unit approaches zero. A method for manufacturing the imaging device according to claim 3,
Arranging the transparent plate with respect to the imaging element substrate, irradiating the imaging element substrate on which the transparent plate is arranged with parallel light, and performing first imaging with the imaging element substrate;
Based on the image signal obtained from the image sensor substrate by the first imaging, the first specific position where the shadow of the horizontal position detection light shielding mask is formed and the shadow of the vertical position detection light shielding mask Obtaining a second specific position where is formed; and
The two third predetermined positions where the acquired straight line connecting the first specific position and the second specific position, the horizontal position detection light shielding mask, and the vertical position detection light shielding mask are to be arranged. Obtaining a tilt angle formed by a straight line connecting
Rotating the transparent plate with respect to the image sensor substrate so that the tilt angle is 0;
Irradiating parallel light onto the image sensor substrate after the rotation of the transparent plate is completed, and performing second imaging with the image sensor substrate;
Based on the image signal obtained from the image sensor substrate by the second imaging, the horizontal component of the first specific position where the shade of the horizontal position detection light-shielding mask is formed, and the vertical position detection Obtaining a vertical component of the second specific position where the shading mask shadow is formed;
A horizontal difference that is a difference between the obtained horizontal component of the first specific position and the horizontal component of the third predetermined position where the horizontal position detection light-shielding mask is to be disposed; and A vertical direction difference that is a difference between the acquired vertical direction component of the second specific position and the vertical direction component of the third predetermined position where the vertical position detection light-shielding mask should be arranged is calculated. And steps to
Translating the transparent plate relative to the imaging device substrate so as to cancel the horizontal difference and the vertical difference;
An image pickup device manufacturing method comprising:

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