Imaging element and imaging device

Abstract

A photographing element includes a first pixel and a second pixel that receive light transmitted through an optical system and output a signal used in focus detection, a third pixel that receives light transmitted through the optical system and outputs a signal used in image generation, and an output section that outputs at least one of a signal of the first pixel and a signal of the second pixel at a timing different from that of the signal of the third pixel, based on information related to the optical system.

Description

[0001] This application is a divisional application of the Chinese patent application No. 201980060861.X, with the title of "Focus detection device, photographing device, and interchangeable lens", filed on July 19, 2019. TECHNICAL FIELD

[0002] The present application relates to a photographing element and a photographing device. BACKGROUND

[0003] A photographing element that reads out a signal for focus detection and a signal for image generation is known (for example, Patent Literature 1). Such a photographing element is desired to be high-speeded in signal readout.

[0004] PRIOR ART DOCUMENT

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 2017-34606 SUMMARY

[0007] According to the first aspect of the application, a focus detection device includes: a photographing section having a first pixel and a second pixel that receive light transmitted through an optical system and output a signal used in focus detection, and a third pixel that receives light transmitted through the optical system and outputs a signal used in image generation; an input section to which information about the optical system is input; a selection section that selects at least one of the first pixel and the second pixel based on the information input to the input section; a readout section that reads out at least one of a signal of the first pixel and a signal of the second pixel at a timing different from a signal of the third pixel based on the selection of the selection section; and a focus detection section that performs focus detection based on at least one of the signal of the first pixel and the signal of the second pixel read out by the readout section.

[0008] According to the second aspect of the application, a photographing device includes: the focus detection device according to the first aspect; and a generation section that generates image data based on a signal output from at least one of the first pixel, the second pixel, and the third pixel.

[0009] According to the third aspect of the application, an interchangeable lens includes a mounting section that is mountable to the focus detection device according to the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is a diagram showing a configuration example of the photographing device according to the first embodiment.

[0011] Figure 2is a view showing a focus detection region of a photographing surface of the photographing device according to the first embodiment.

[0012] Figure 3 is a view showing a configuration example of pixels in the focus detection region of the photographing device according to the first embodiment.

[0013] Figure 4 is a view showing a configuration example of pixels in the photographing device according to the first embodiment.

[0014] Figure 5 is a sectional view showing three kinds of AF pixel pairs arranged in a central region in the photographing device according to the first embodiment.

[0015] Figure 6 is a sectional view showing three kinds of AF pixel pairs arranged in a region of a predetermined image height position in the photographing device according to the first embodiment.

[0016] Figure 7 is a sectional view showing three kinds of AF pixel pairs arranged in a region of a predetermined image height position in the photographing device according to the first embodiment.

[0017] Figure 8 is a view showing a relationship between a reference exit pupil and an image height in the photographing device according to the first embodiment.

[0018] Figure 9 is a view showing various optical characteristics of the interchangeable lens in the photographing device according to the first embodiment, in which an exit pupil distance varies according to an image height.

[0019] Figure 10 is a view showing a relationship between an image height and an exit pupil in the photographing device according to the first embodiment.

[0020] Figure 11 is a table showing a focus position interval in the photographing device according to the first embodiment and a constant term and a coefficient of a function approximating a representative optical characteristic curve of the focus position interval.

[0021] Figure 12 is a table showing an interval in the photographing device according to the first embodiment and a constant term and a coefficient of a function approximating a representative optical characteristic curve of the interval.

[0022] Figure 13 is a view showing a threshold value, a first exit pupil distance range to a third exit pupil distance range, and an optical characteristic curve related to an exit pupil distance in the photographing device according to the first embodiment.

[0023] Figure 14is a view showing a circuit structure of a pixel of a photographing element according to the first embodiment.

[0024] Figure 15 is a view showing a part of a configuration of a photographing element according to the first embodiment.

[0025] Figure 16 is a view showing a configuration example of an AF pixel in a photographing device according to the modification example.

[0026] Figure 17 is a view showing a configuration example of an AF pixel in a photographing device according to the modification example. DETAILED DESCRIPTION

[0027] (First Embodiment)

[0028] Figure 1 is a view showing a configuration example of an electronic camera 1 (hereinafter referred to as a camera 1) as one example of a photographing device according to the first embodiment. The camera 1 is configured of a camera body 2 and a replaceable lens 3. Since the camera 1 is configured of the camera body 2 and the replaceable lens 3, it is also sometimes referred to as a camera system.

[0029] A body-side fixing portion 201 for mounting the replaceable lens 3 is provided in the camera body 2. A lens-side fixing portion 301 mountable to the camera body 2 is provided in the replaceable lens 3. A lens-side connecting portion 302 and a body-side connecting portion 202 are respectively provided in the lens-side fixing portion 301 and the body-side fixing portion 201. A plurality of terminals such as a clock signal terminal, a data signal terminal, and a power supply terminal are respectively provided in the lens-side connecting portion 302 and the body-side connecting portion 202. The replaceable lens 3 is detachably mounted to the camera body 2 by the lens-side fixing portion 301 and the body-side fixing portion 201.

[0030] When the replaceable lens 3 is mounted to the camera body 2, the terminals provided in the body-side connecting portion 202 are electrically connected to the terminals provided in the lens-side connecting portion 302. Thereby, power supply from the camera body 2 to the replaceable lens 3 and communication between the camera body 2 and the replaceable lens 3 can be performed.

[0031] The replaceable lens 3 has a photographing optical system (imaging optical system) 31, a lens control portion 32, and a lens memory 33. The photographing optical system 31 has a plurality of lenses including a zoom lens (variable power lens) 31a that changes a focal length, a focus lens (focus adjustment lens) 31b, and an aperture 31c, and forms an object image on a photographing surface 22a of a photographing element 22. In addition, in the photographing optical system 31, a plurality of lenses including the zoom lens 31a and the focus lens 31b are illustrated schematically, but a general photographing optical system is generally configured of a large number of optical elements. Figure 1 In the photographing optical system 31, the zoom lens 31a and the focus lens 31b are illustrated schematically, but a general photographing optical system is generally configured of a large number of optical elements.

[0032] As will be described later, the imaging optical system 31 of the interchangeable lens 3 has an optical characteristic in which the position of its exit pupil, that is, the exit pupil distance, changes according to the image height. In other words, the exit pupil distance of the imaging optical system 31 changes according to its position within the imaging plane 22a, that is, the distance from the optical axis OA1 of the imaging optical system 31 within the imaging plane 22a. The optical axis OA1 of the imaging optical system 31 intersects the imaging plane 22a at the center of the imaging plane 22a. Alternatively, it can be said that the exit pupil distance of the imaging optical system 31 changes according to the distance from the center of the imaging plane 22a. Here, the exit pupil distance refers to the distance between the exit pupil of the imaging optical system 31 and the image plane of the image of the imaging optical system 31. Furthermore, the imaging plane 22a of the imaging element 22 is, for example, the surface on which the photoelectric conversion unit, described later, is arranged, or the surface on which the microlenses are arranged.

[0033] Furthermore, the photographing optical system 31 differs depending on the type of interchangeable lens 3 attached to the body-side mount 201. Therefore, the exit pupil distance of the photographing optical system 31 differs depending on the type of interchangeable lens 3. Furthermore, the optical characteristics of the exit pupil distance, which vary depending on the image height, also differ depending on the type of interchangeable lens 3.

[0034] The lens control unit 32, comprised of a processor such as a CPU, FPGA, or ASIC, and memory such as ROM and RAM, controls various components of the interchangeable lens 3 based on control programs. Based on signals output from the body control unit 210 of the camera body 2, the lens control unit 32 controls the position of the zoom lens 31a, the position of the focus lens 31b, and the drive of the aperture 31c. Upon receiving a signal from the body control unit 210 indicating the direction and amount of movement of the focus lens 31b, the lens control unit 32 moves the focus lens 31b forward and backward along the optical axis OA1 based on the signal, thereby adjusting the focal position of the photographic optical system 31. Furthermore, based on signals output from the body control unit 210 of the camera body 2, the lens control unit 32 controls the position of the zoom lens 31a and the aperture diameter of the aperture 31c.

[0035] The lens memory 33 is constituted by a nonvolatile storage medium or the like, for example. In the lens memory 33, information associated with the interchangeable lens 3 is stored (recorded) as lens information. The lens information includes data on the optical characteristics (exit pupil distance, F value) of the photographing optical system 31, data on the infinity position and the close-up position of the focus lens 31b, data on the shortest focal length and the longest focal length of the interchangeable lens 3, and the like. Further, the lens information differs depending on the kind of the interchangeable lens 3. In addition, the lens information can be stored in a memory inside the lens control section 32. In addition, the lens information can be stored in the camera body memory 23 possessed by the camera body 2 described later. In this case, the camera body memory 23 stores the lens information of a plurality of interchangeable lenses 3.

[0036] In the present embodiment, the lens information includes information on the exit pupil distance of the photographing optical system 31. The information on the exit pupil distance will be described later, but includes information indicating the exit pupil distance (Co) at the position where the photographing surface 22a intersects with the optical axis OA1 (the position at which the image height is zero), and information on coefficients (h4, h2) included in an arithmetic expression indicating the relationship between the exit pupil distance and the image height. The writing of data to the lens memory 33 and the reading of data from the lens memory 33 are controlled by the lens control section 32. When the interchangeable lens 3 is mounted to the camera body 2, the lens control section 32 transmits the lens information to the camera body control section 210 via the terminals of the lens-side connection section 302 and the body-side connection section 202. In addition, the lens control section 32 transmits, to the camera body control section 210, information on the position of the zoom lens 31a after the control (focal length information), information on the position of the focus lens 31b after the control, information on the F value of the diaphragm 31c after the control, and the like.

[0037] In the present embodiment, the lens control section 32 functions as an output section that transmits information on the exit pupil distance of the photographing optical system 31 to the camera body 2. The camera body control section 210 functions as an input section that is input with information on the exit pupil distance of the photographing optical system 31 from the interchangeable lens 3.

[0038] Further, the lens control section 32 performs communication of bidirectionally transmitting and receiving information between the camera body 2 and the interchangeable lens 3 via the terminals of the lens-side connecting section 302 and the body-side connecting section 202. The lens control section 32 transmits information on the exit pupil distance to the camera body 2 when a signal is inputted from the camera body 2 to request transmission of the information on the exit pupil distance (h4, h2, Co). Further, the information on the exit pupil distance differs depending on the type of the interchangeable lens 3. Further, the lens control section 32 can transmit the information on the exit pupil distance to the camera body 2 each time the imaging element 22 performs imaging. The lens control section 32 can also transmit the information on the exit pupil distance to the camera body 2 when the focal length of the imaging optical system 31 changes as the zoom lens 31a moves. The lens control section 32 can also transmit the information on the focal length of the imaging optical system 31 and the information on the exit pupil distance to the camera body 2 by one bidirectional communication.

[0039] Next, the configuration of the camera body 2 will be described. The camera body 2 is provided with an imaging element 22, a body memory 23, a display section 24, an operation section 25, and a body control section 210. The imaging element 22 is a CMOS image sensor, a CCD image sensor. The imaging element 22 images an object image formed by the imaging optical system 31. A plurality of pixels of the imaging element 22 having a photoelectric conversion section are arranged in two dimensions (in a row direction and a column direction). The photoelectric conversion section is constituted by a photodiode (PD). The imaging element 22 generates a signal by photoelectrically converting light received with the photoelectric conversion section, and outputs the generated signal to the body control section 210.

[0040] As will be described later, the imaging element 22 has imaging pixels that output signals used in image generation, and AF pixels (focus detection pixels) that output signals used in focus detection. The imaging pixels include: a pixel having a filter having a light-splitting characteristic that splits a light of a first wavelength range (a light of red (R)) of the incident light (hereinafter referred to as an R pixel); a pixel having a filter having a light-splitting characteristic that splits a light of a second wavelength range (a light of green (G)) of the incident light (hereinafter referred to as a G pixel); and a pixel having a filter having a light-splitting characteristic that splits a light of a third wavelength range (a light of blue (B)) of the incident light (hereinafter referred to as a B pixel). The R pixels, the G pixels, and the B pixels are arranged in a Bayer arrangement. The AF pixels are arranged in a manner that a part of the imaging pixels is replaced, and are dispersedly arranged on substantially the entire surface of the imaging surface 22a of the imaging element 22. Further, in the following description, in the case of being simply referred to as a pixel, either one or both of the imaging pixels and the AF pixels are meant.

[0041] The body memory 23 is composed of, for example, a nonvolatile storage medium. Image data, control programs, and the like are recorded in the body memory 23. Writing data to and reading data from the body memory 23 are controlled by the body control unit 210. The display unit 24 displays an image based on the image data, an image showing the focus detection area (AF area) such as the AF frame, information related to shooting such as the shutter speed and F value, and a menu screen. The operation unit 25 includes various setting switches such as a release button, a power switch, and switches for switching between various modes, and outputs signals corresponding to each operation to the body control unit 210. The operation unit 25 is a setting unit that can set an arbitrary focus detection area from a plurality of focus detection areas, and the user can select an arbitrary focus detection area by operating the operation unit 25.

[0042] The body control unit 210 is composed of a processor such as a CPU, FPGA, or ASIC, and memory such as ROM and RAM, and controls various components of the camera 1 based on a control program. The body control unit 210 includes an area setting unit 211, a distance calculation unit 212, a pixel selection unit 213, a readout unit 214, a focus detection unit 215, and an image data generation unit 216.

[0043] The area setting unit 211 is set to Figure 2 At least one focus detection area 100 is set (selected) from among the multiple focus detection areas 100 on the imaging surface 22a of the imaging element 22 shown in (a). The multiple AF frames displayed on the display unit 24 correspond to the multiple focus detection areas 100 provided on the imaging element 22. The area setting unit 211 sets the focus detection area 100 corresponding to the AF frame selected by the user through the operation of the operation unit 25 among the multiple AF frames displayed on the display unit 24, or the focus detection area 100 automatically selected by the camera 1, as the area for focus detection. Although described later, the focus detection unit 215 detects the amount of deviation (defocus) between the image of the imaging optical system 31 and the imaging surface 22a using the signals output from the AF pixels within the focus detection area 100 set by the area setting unit 211.

[0044] like Figure 2As schematically shown in (b), in addition to the shooting pixels, multiple types of pairs of AF pixels (AF pixel pairs) are arranged in the focus detection area 100. In this embodiment, a first AF pixel pair, a second AF pixel pair, and a third AF pixel pair are arranged. In order to accurately detect the defocus amount even if the exit pupil distance varies depending on the image height or the type of interchangeable lens, the first AF pixel pair, the second AF pixel pair, and the third AF pixel pair are arranged. The AF pixels constituting one side of the AF pixel pair output the first signal Sig1, and the AF pixels constituting the other side of the AF pixel pair output the second signal Sig2. The first AF pixel pair, the second AF pixel pair, and the third AF pixel pair will be described later.

[0045] In addition, if Figure 2 As shown in (a), a plurality of focus detection areas 100 are arranged in two-dimensional directions (row and column directions) and are set at positions with different image heights. A small area 110a (see FIG. 1 ) within the focus detection area 100a at the center of the imaging surface 22a Figure 2 (b)) is located on the optical axis OA1 of the imaging optical system 31, and its image height H is approximately zero. As the focus detection area 100 moves away from the center of the imaging surface 22a (the optical axis OA1 of the imaging optical system 31), its image height H increases. In other words, as the distance from the center of the imaging surface 22a increases, the image height H of the focus detection area 100 increases. Therefore, in the row where the focus detection area 100a is located, the focus detection areas 100 farthest from the optical axis OA1 of the imaging optical system 31 (with the highest image height H) are the focus detection areas 100b and 100c located at the left end (the end in the -X direction) and the right end (the end in the +X direction) of the row. In the imaging element 22, the focus detection areas 100 with the highest image height H are the four focus detection areas 100 located at the corners of the imaging surface 22a.

[0046] Furthermore, the focus detection area 100 has a predetermined area, and therefore the image height varies for each AF pixel depending on the position within the focus detection area 100. The central small area 110a (see FIG. 110b ) within the same focus detection area 100 is Figure 2 (b)) and small areas 110b and 110c located at the left end (end in the -X direction) and the right end (end in the +X direction) (refer to Figure 2 However, in this embodiment, the image height H at the center of one focus detection area 100 is used as the image height of the entire focus detection area 100. The image height of the focus detection area 100a at the center of the imaging surface 22a is zero, and the image heights of the focus detection areas 100b and 100c are the predetermined image height H.

[0047] The distance calculation section 212 calculates the exit pupil distance of the photographing optical system 31 at the image height H. The distance calculation section 212 calculates the exit pupil distance Po(H) of the focus detection area 100 set by the area setting section 211 at the image height H by the following equation (1).

[0048] Po(H) = h4 x H 4 + h2 x H 2 + Co … (1)

[0049] Equation (1) is an operation formula in which the image height H is a variable, the parameter (h4) is a coefficient of the 4th order term of the variable H, the parameter (h2) is a coefficient of the 2nd order term of the variable H, and the constant term Co is the exit pupil distance at the position where the image height is zero (the position of the optical axis OA1 in the photographing surface 22a). The parameters (h4), (h2), and the constant term Co are information on the exit pupil distance corresponding to different image heights, and are values determined in accordance with the optical characteristics of the photographing optical system 31. The information indicating the parameters (h4), (h2), and the constant term Co is transmitted from the interchangeable lens 3 to the camera body 2 as lens information. Further, this operation formula (1) is stored in a memory inside the body control section 210.

[0050] The distance calculation section 212 calculates the exit pupil distance Po(H) related to the image height H of the focus detection area 100 set by the area setting section 211, based on the image height H of the focus detection area 100 set by the area setting section 211, the lens information (h4, h2, Co), and the operation formula (1). Further, the operation formula (1) can also be stored in a memory inside the lens control section 32. The lens control section 32 can also transmit the operation formula (1) to the camera body 2 as lens information together with the parameters (h4), (h2), and the constant term Co.

[0051] The pixel selection section 213 selects at least one AF pixel pair of a plurality of kinds of AF pixel pairs provided to the photographing element 22. In the present embodiment, the pixel selection section 213 selects a certain kind of AF pixel pair among the three kinds of AF pixel pairs (1st to 3rd AF pixel pairs) arranged within the focus detection area 100 set by the area setting section 211. Although it will be described later, the pixel selection section 213 selects an AF pixel pair suitable for the exit pupil distance Po(H) calculated by the distance calculation section 212 from among the three kinds of AF pixel pairs. In addition, in a case where a plurality of focus detection areas 100 are set by the area setting section 211, the pixel selection section 213 selects the same kind of AF pixel pair in each of the selected focus detection areas 100.

[0052] The readout section 214 reads out a signal from the imaging element 22. The readout section 214 reads out a signal used in image generation, a signal used in focus detection, from the imaging element 22 at a predetermined cycle in a case where the display section 24 displays a through image (live view image) of an object, in a case where the dynamic image capturing is performed. The readout section 214 sequentially selects a pixel of the imaging element 22 in units of a row, and reads out a signal in a so-called rolling shutter manner in which a signal is read out from the selected pixel row.

[0053] The readout section 214 performs a first readout mode and a second readout mode. In the first readout mode, the readout section 214 sequentially selects a pixel row in which an AF pixel configuring an AF pixel pair selected by the pixel selection section 213 (hereinafter referred to as an AF pixel row) and a pixel row in which no AF pixel is arranged (hereinafter referred to as a capturing pixel row), and reads out a signal from each pixel. In the second readout mode, the readout section 214 separately performs reading out of a signal from the AF pixel row and reading out of a signal from the capturing pixel row.

[0054] For example, the readout section 214 performs the first readout mode in a case where a still image is continuously captured, in a case where a high-resolution dynamic image is captured (for example, 4K dynamic image capturing). In addition, the readout section 214 performs the second readout mode in a case where the display section 24 displays a through image, in a case where a low-resolution dynamic image is captured (for example, Full HD dynamic image capturing). The first readout mode and the second readout mode will be described later.

[0055] The focus detection section 215 performs a focus detection process required for automatic focus adjustment (AF) of the photographing optical system 31. The focus detection section 215 detects a focus position (an amount of movement of the focus lens 31b up to the focus position) of the focus lens 31b on which an image of the photographing optical system 31 is focused (imaged) on the imaging surface 22a. The focus detection section 215 calculates a defocus amount by a pupil division type phase difference detection method using the first signal Sig1 and the second signal Sig2 of the AF pixel pair read out by the readout section 214.

[0056] The focus detection section 215 performs a correlation operation on the first signal Sig1 generated by capturing an image generated by a first light flux passing through a first pupil region of an exit pupil of the photographing optical system 31 and the second signal Sig2 generated by capturing an image generated by a second light flux passing through a second pupil region, and calculates an image shift amount. The focus detection section 215 converts the image shift amount into a defocus amount on the basis of a predetermined conversion formula. The focus detection section 215 calculates an amount of movement of the focus lens 31b up to the focus position on the basis of the calculated defocus amount.

[0057] The focus detection section 215 determines whether the defocus amount is within the allowable value. If the defocus amount is within the allowable value, the focus detection section 215 determines that the focus is in focus. On the other hand, the focus detection section 215 determines that the focus is out of focus if the defocus amount exceeds the allowable value, and transmits a signal instructing the movement amount of the focus lens 31b and the lens movement to the lens control section 32 of the interchangeable lens 3. The lens control section 32 automatically performs focus adjustment by causing the focus lens 31b to move according to the movement amount.

[0058] In addition, the focus detection section 215 can also perform focus detection processing in the contrast detection method in addition to the focus detection processing in the phase difference detection method. The body control section 210 calculates the contrast evaluation value of the subject image based on the signals output from the imaging pixels while moving the focus lens 31b of the imaging optical system 31 in the optical axis OA1 direction. The body control section 210 performs correlation between the position of the focus lens 31b and the contrast evaluation value using the position information of the focus lens 31b transmitted from the interchangeable lens 3. Furthermore, the body control section 210 detects the position of the focus lens 31b at which the contrast evaluation value shows a peak, that is, a maximum value, as the in-focus position. The body control section 210 transmits information of the position of the focus lens 31b corresponding to the detected in-focus position to the lens control section 32. The lens control section 32 moves the focus lens 31b to the in-focus position to perform focus adjustment.

[0059] The image data generation section 216 performs various image processing on the signals of the imaging pixels read out by the readout section 214, and generates image data. In addition, the image data generation section 216 can also generate image data using the signals output from the AF pixels.

[0060] Figure 3 is a diagram showing an example of the arrangement of pixels within the focus detection region 100. The R pixels 13, the G pixels 13, and the B pixels 13 are arranged in a Bayer arrangement. The 1st AF pixel 11 and the 2nd AF pixel 12 are arranged in a manner in which a part of the imaging pixels 13 performing the Bayer arrangement is replaced. The 1st AF pixel 11 and the 2nd AF pixel 12 each have a light shielding section 43. The positions of the light shielding sections 43 of the 1st AF pixel 11 and the 2nd AF pixel 12 are different.

[0061] As Figure 3As shown, the imaging element 22 has a pixel group (1st imaging pixel row) 401 in which R pixels 13 and G pixels 13 are alternately arranged in the horizontal direction, i.e., the row direction, and a pixel group (2nd imaging pixel row) 402 in which G pixels 13 and B pixels 13 are alternately arranged in the row direction. In addition, the imaging element 22 has a pixel group (1st AF pixel row) 403 in which G pixels 13 and 1st AF pixels 11 are alternately arranged in the row direction, and a pixel group (2nd AF pixel row) 404 in which G pixels 13 and 2nd AF pixels 12 are alternately arranged in the row direction.

[0062] The 1st AF pixel 11a and the G pixel 13 are alternately arranged in the 1st AF pixel row 403a. The 2nd AF pixel 12a and the G pixel 13 are alternately arranged in the 2nd AF pixel row 404a which is apart from the 1st AF pixel row 403a by a predetermined row. In addition, the arrangement position of the 1st AF pixel 11a in the 1st AF pixel row 403a and the arrangement position of the 2nd AF pixel 12a in the 2nd AF pixel row 404a are the same as each other. That is, the 1st AF pixel 11a and the 2nd AF pixel 12a are arranged in the same column. The 1st AF pixel 11a of the 1st AF pixel row 403a and the 2nd AF pixel 12a of the 2nd AF pixel row 404a constitute a 1st AF pixel pair.

[0063] The 1st AF pixel 11b and the G pixel 13 are alternately arranged in the 1st AF pixel row 403b which is apart from the 2nd AF pixel row 404a by a predetermined row. The 2nd AF pixel 12b and the G pixel 13 are alternately arranged in the 2nd AF pixel row 404b which is apart from the 1st AF pixel row 403b by a predetermined row. In addition, the arrangement position of the 1st AF pixel 11b in the 1st AF pixel row 403b and the arrangement position of the 2nd AF pixel 12b in the 2nd AF pixel row 404b are the same as each other. That is, the 1st AF pixel 11b and the 2nd AF pixel 12b are arranged in the same column. The 1st AF pixel 11b of the 1st AF pixel row 403b and the 2nd AF pixel 12b of the 2nd AF pixel row 404b constitute a 2nd AF pixel pair.

[0064] The 1st AF pixel 11c and the G pixel 13 are alternately arranged in the 1st AF pixel row 403c which is apart from the 2nd AF pixel row 404b by a predetermined row. The 2nd AF pixel 12c and the G pixel 13 are alternately arranged in the 2nd AF pixel row 404c which is apart from the 1st AF pixel row 403c by a predetermined row. In addition, the arrangement position of the 1st AF pixel 11c in the 1st AF pixel row 403c and the arrangement position of the 2nd AF pixel 12c in the 2nd AF pixel row 404c are the same as each other. That is, the 1st AF pixel 11c and the 2nd AF pixel 12c are arranged in the same column. The 1st AF pixel 11c of the 1st AF pixel row 403c and the 2nd AF pixel 12c of the 2nd AF pixel row 404c constitute a 3rd AF pixel pair.

[0065] Further, a plurality of the first AF pixel pairs can be configured for the first AF pixel row 403a and the second AF pixel row 404a configured in a plurality of rows. In addition, a plurality of the second AF pixel pairs can be configured for the first AF pixel row 403b and the second AF pixel row 404b configured in a plurality of rows. A plurality of the third AF pixel pairs can be configured for the first AF pixel row 403c and the second AF pixel row 404c configured in a plurality of rows.

[0066] Further, as described above, the first AF pixel pair, the second AF pixel pair, and the third AF pixel pair are configured to accurately detect the defocus amount even if the exit pupil distance varies depending on the image height or the type of the interchangeable lens. Therefore, the area of the light-shielding portion 43 possessed by each of the first AF pixel pair, the second AF pixel pair, and the third AF pixel pair is different from that of the pixel pair located around the optical axis OAl (the center of the imaging surface 22a) of the photographing optical system 31. When the exit pupil distance is different, the incident angle of the light incident on the AF pixel is different from that of the AF pixel located around the optical axis OAl of the photographing optical system 31. When the exit pupil distance is shorter, the incident angle is larger, and when the exit pupil distance is longer, the incident angle is smaller. In order to shield a part of the light incident at the incident angle different depending on the exit pupil distance, the area of the light-shielding portion 43 is different depending on the AF pixel pair. Thus, the focus detection unit 215 can accurately detect the defocus amount even if the exit pupil distance is different. However, the incident angle of the pixel pair located around the optical axis OAl (the center of the imaging surface 22a) of the photographing optical system 31 is 0° regardless of the exit pupil distance. Therefore, the area of the light-shielding portion 43 possessed by each of the first AF pixel pair, the second AF pixel pair, and the third AF pixel pair is the same. Although this will be described later, the area of the light-shielding portion 43 is different depending on the position (image height) of the AF pixel.

[0067] The first AF pixels 11a, 11b, 11c and the second AF pixels 12a, 12b, 12c each have a color filter having a light-splitting property of splitting the light of the second wavelength range (light of green (G)) among the incident light. Further, the color filter possessed by each of the first AF pixels 11a to 11c and the second AF pixels 12a to 12c can be a color filter having a light-splitting property of splitting the light of the first wavelength range (light of red (R)) or the third wavelength range (light of blue (B)). In addition, the first AF pixels 11a to 11c and the second AF pixels 12a to 12c can have a color filter having a light-splitting property of splitting the light of the first wavelength range, the second wavelength range, and the third wavelength range among the incident light.

[0068] Figure 4This is a diagram for explaining a configuration example of AF pixels and imaging pixels provided in the imaging element 22 according to the first embodiment. Figure 4 (a) shows an example of a cross section of the first AF pixel 11 of the first AF pixel 11 and the second AF pixel 12 constituting the AF pixel pair. Figure 4 (b) shows an example of a cross section of the second AF pixel 12 of the first AF pixel 11 and the second AF pixel 12 . Figure 4 (c) shows an example of a cross section of the imaging pixel 13 (R pixel, G pixel, B pixel).

[0069] exist Figure 4 In the image capturing pixel 13, the first AF pixel 11, the second AF pixel 12, and the imaging pixel 13 all include a microlens 44, a color filter 51, and a photoelectric converter 42 (PD 42) that performs photoelectric conversion on light that has passed through the microlens 44 and the color filter 51. The first light beam 61 passes through the first pupil region that roughly divides the exit pupil of the imaging optical system 31 into two equal parts. The second light beam 62 passes through the second pupil region that roughly divides the exit pupil of the imaging optical system 31 into two equal parts.

[0070] exist Figure 4 In (a), the first AF pixel 11 is provided with a light shielding portion 43L for shielding the second light beam 62 of the first light beam 61 and the second light beam 62. The light shielding portion 43L is located between the color filter 51 and the photoelectric conversion portion 42 and is provided on the photoelectric conversion portion 42. Figure 4 In the example shown in (a), the light shielding portion 43L is configured to shield the left half (the -X direction side) of the photoelectric converter 42. The right end (the end in the +X direction) of the light shielding portion 43L is substantially aligned with the center line that bisects the photoelectric converter 42. The photoelectric converter 42 of the first AF pixel 11 receives the first light beam 61. The photoelectric converter 42 of the first AF pixel 11 performs photoelectric conversion on the first light beam 61 to generate charge, and the first AF pixel 11 outputs a first signal Sig1 based on the charge generated in the photoelectric converter 42.

[0071] Furthermore, the area of ​​the light shielding portion 43L varies depending on the position (image height) of the first AF pixel 11, except for the first AF pixel 11 located near the optical axis OA1 (the center of the imaging surface 22a) of the imaging optical system 31. When the position of the first AF pixel 11 varies, that is, when the image height varies, the angle of incidence of light entering the first AF pixel 11 varies. As the image height increases, the angle of incidence increases, while as the image height decreases, the angle of incidence decreases. When the image height is zero, the angle of incidence is 0°. In order to shield the second light beam 62 of light entering at angles that vary depending on the image height, the area of ​​the light shielding portion 43L varies depending on the image height.

[0072] exist Figure 4 In (b), the second AF pixel 12 is provided with a light shielding portion 43R for shielding the first light beam 61 of the first light beam 61 and the second light beam 62. The light shielding portion 43R is located between the color filter 51 and the photoelectric conversion portion 42 and is provided on the photoelectric conversion portion 42. Figure 4 In the example shown in (b), the light shielding portion 43R is configured to shield the right half (+X direction side) of the photoelectric converter 42. The left end (the end in the -X direction) of the light shielding portion 43R is substantially aligned with the center line that bisects the photoelectric converter 42. The photoelectric converter 42 of the second AF pixel 12 receives the second light beam 62. The photoelectric converter 42 of the second AF pixel 12 performs photoelectric conversion on the second light beam 62 to generate charge, and the second AF pixel 12 outputs a second signal Sig2 based on the charge generated in the photoelectric converter 42.

[0073] Furthermore, similarly to the first AF pixel 11, the area of ​​the light shielding portion 43R varies depending on the position (image height) of the second AF pixel 12, except for the second AF pixel 12 located around the optical axis OA1 (center of the imaging surface 22a) of the imaging optical system 31. The area of ​​the light shielding portion 43R varies depending on the image height in order to shield the first light beam 61 of the light incident at an incident angle that varies depending on the image height.

[0074] exist Figure 4 In (c), the photoelectric converter 42 of the imaging pixel 13 receives the first light beam 61 and the second light beam 62 that have respectively passed through the first pupil area and the second pupil area of ​​the exit pupil of the imaging optical system 31. The photoelectric converter 42 of the imaging pixel 13 performs photoelectric conversion on the first light beam 61 and the second light beam 62 to generate electric charge, and the imaging pixel 13 outputs a signal based on the electric charge generated in the photoelectric converter 42.

[0075] Figure 5 It is a small area 110a within the focus detection area 100a (refer to Figure 2 (b) Cross-sectional view of three types of AF pixel pairs configured. Figure 5 (a) indicates that the components are respectively configured in Figure 3 The first AF pixel row 403a and the second AF pixel row 404a include the first AF pixel 11a and the second AF pixel 12a of the first AF pixel pair. Figure 5 (b) indicates that the components are respectively configured in Figure 3 The first AF pixel row 403b and the second AF pixel row 404b include the first AF pixel 11b and the second AF pixel 12b of the second AF pixel pair. Figure 5 (c) indicates that the components are respectively configured in Figure 3the 1st AF pixel 11c and the 2nd AF pixel 12c of the 3rd AF pixel pair of the 2nd AF pixel row 404c. As shown in Figure 5 The line passing through the center of the photoelectric conversion section 42 and the optical axis OA2 of the microlens 44 are substantially coincident with each other for each of the 1st AF pixels 11a to 11c and the 2nd AF pixels 12a to 12c. Light that has entered at an incident angle of 0° with respect to the optical axis OA2 of the microlens 44 is condensed on the optical axis OA2 of the microlens. The line passing through the center of the photoelectric conversion section 42 coincides with the optical axis OA2 of the microlens 44, and thus light that has entered the microlens 44 is condensed on the line passing through the center of the photoelectric conversion section 42. That is, light that has passed through the photographing optical system 31 is condensed on the line passing through the center of the photoelectric conversion section 42.

[0076] In Figure 5 (a), the right end (+X-direction end) of the light-blocking section 43L of the 1st AF pixel 11a substantially coincides with the optical axis OA2 of the microlens 44. The light-blocking section 43L of the 1st AF pixel 11a blocks light from the left half (-X-direction side) of the photoelectric conversion section 42. The 2nd light beam 62 that has passed through the microlens 44 is blocked by the light-blocking section 43L before being input to the photoelectric conversion section 42. Thus, the photoelectric conversion section 42 of the 1st AF pixel 11a receives the 1st light beam 61. The left end (-X-direction end) of the light-blocking section 43R of the 2nd AF pixel 12a substantially coincides with the optical axis OA2 of the microlens 44. The 1st light beam 61 that has transmitted the microlens 44 is blocked by the light-blocking section 43R before being incident on the photoelectric conversion section 42. Thus, the photoelectric conversion section 42 of the 2nd AF pixel 12a receives the 2nd light beam 62.

[0077] As shown in Figure 5 (b) and (c), the right end (+X-direction end) of the light-blocking section 43L of each of the 1st AF pixels 11b and 11c substantially coincides with the optical axis OA2 of the microlens 44. Thus, as with the 1st AF pixel 11a, the photoelectric conversion section 42 of each of the 1st AF pixels 11b and 11c receives the 1st light beam 61. In addition, the left end (-X-direction end) of the light-blocking section 43R of each of the 2nd AF pixels 12b and 12c substantially coincides with the optical axis OA2 of the microlens 44. Thus, as with the 1st AF pixel 12a, the photoelectric conversion section 42 of each of the 2nd AF pixels 12b and 12c receives the 2nd light beam 62.

[0078] Figure 6 is a sectional view of the three AF pixel pairs arranged in the small region 110c (refer to Figure 2 (b)) that is apart from the small region 110a in the focus detection region 100a in the +X direction. Figure 6(a) shows the first AF pixel 11 a and the second AF pixel 12 a constituting the first AF pixel pair. Figure 6 (b) shows the first AF pixel 11b and the second AF pixel 12b constituting the second AF pixel pair. Figure 6 (c) shows the first AF pixel 11 c and the second AF pixel 12 c constituting the third AF pixel pair.

[0079] exist Figure 6 In the embodiment, the lines passing through the center of the photoelectric converter 42 of each of the first AF pixels 11a to 11c and the second AF pixels 12a to 12c are offset in the +X direction relative to the optical axis OA2 of the microlens 44. In the present embodiment, the lines passing through the center of the photoelectric converter 42 of the first AF pixels and the second AF pixels arranged away from the small area 110a in the +X direction are offset in the +X direction relative to the optical axis OA2 of the microlens 44. Furthermore, the lines passing through the center of the photoelectric converter 42 of the first AF pixels and the second AF pixels arranged away from the small area 110a in the -X direction are offset in the -X direction relative to the optical axis OA2 of the microlens 44.

[0080] In addition, Figure 6 1. The first AF pixels 11a to 11c each have a different area of ​​light-shielding portion 43L. The area of ​​the light-shielding portion 43L of the first AF pixel 11a is smaller than the area of ​​the light-shielding portion 43L of the first AF pixel 11b. The area of ​​the light-shielding portion 43L of the first AF pixel 11b is smaller than the area of ​​the light-shielding portion 43L of the first AF pixel 11c. The area of ​​the light-shielding portion 43R of the second AF pixels 12a to 12c each has a different area. The area of ​​the light-shielding portion 43R of the second AF pixel 12a is larger than the area of ​​the light-shielding portion 43R of the second AF pixel 12b. The area of ​​the light-shielding portion 43R of the second AF pixel 12b is larger than the area of ​​the light-shielding portion 43R of the second AF pixel 12c.

[0081] exist Figure 6 In FIG, the line passing through the center of the photoelectric conversion unit 42 is offset from the optical axis OA2 of the microlens 44, and the areas of the light shielding portions 43 of the first AF pixel and the second AF pixel are different. Therefore, the ends of the light shielding portions of the first AF pixel and the second AF pixel are offset from the optical axis OA2 of the microlens 44. Figure 6 For example, in (a), the right end (end in the +X direction) of the light shielding portion 43L of the first AF pixel 11a is located at a position offset by an amount d1 in the +X direction relative to the optical axis OA2 of the microlens 44. Furthermore, the left end (end in the -X direction) of the light shielding portion 43R of the second AF pixel 12a is located at a position offset by an amount d1 in the +X direction relative to the optical axis OA2 of the microlens 44.

[0082] like Figure 6As shown, the shift amounts of the 2nd AF pixel pair and the 3rd AF pixel pair from the 1st AF pixel pair are different. The shift amount d2 of the 1st AF pixel 11b and the 2nd AF pixel 12b constituting the 2nd AF pixel pair is larger than the shift amount d1 of the 1st AF pixel 11a and the 2nd AF pixel 12a constituting the 1st AF pixel pair. The shift amount d3 of the 1st AF pixel 11c and the 2nd AF pixel 12c constituting the 3rd AF pixel pair is larger than the shift amount d2 of the 1st AF pixel 11b and the 2nd AF pixel 12b constituting the 2nd AF pixel pair. That is, d1 < d2 < d3.

[0083] Figure 7 is a cross-sectional view of a part of the focus detection area 100c, which is apart from the focus detection area 100a of Figure 2 Figure 7 (a) of FIG. 1 1 shows the 1st AF pixel 11a and the 2nd AF pixel 12a constituting the 1st AF pixel pair. Figure 7 (b) of FIG. 1 1 shows the 1st AF pixel 11b and the 2nd AF pixel 12b constituting the 2nd AF pixel pair. Figure 7 (c) of FIG. 1 1 shows the 1st AF pixel 11c and the 2nd AF pixel 12c constituting the 3rd AF pixel pair.

[0084] As shown in FIG. 1 1, Figure 6 As shown in FIG. 1 1, Figure 7 As shown in FIG. 1 1, the lines passing through the centers of the 1st AF pixels 1 1a to 1 1c and the 2nd AF pixels 12a to 12c are shifted in the +X direction with respect to the optical axis OA2 of the microlens 44. In addition, as shown in FIG. 1 1, Figure 6 As shown in FIG. 1 1, the areas of the light-shielding portions 43L of the 1st AF pixels 1 1a to 1 1c are different. The areas of the light-shielding portions 43R of the 2nd AF pixels 12a to 12c are different.

[0085] In addition, Figure 6 As shown in FIG. 1 1, Figure 7 As shown in FIG. 1 1, the shift amounts of the lines passing through the centers of the three kinds of AF pixel pairs with respect to the optical axis OA2 of the microlens 44 are different. In addition, the areas of the light-shielding portions 43L are different from the areas of the light-shielding portions 43R except for the 1st AF pixel 1 1b and the 2nd AF pixel 12b. As shown in FIG. 1 1, Figure 6 As shown in FIG. 1 1, Figure 7 As shown in FIG. 1 1, the shift amounts of the three kinds of AF pixel pairs with respect to the optical axis OA2 of the microlens 44 are large. In addition, as shown in FIG. 1 1, Figure 6 As shown in FIG. 1 1, Figure 7 As shown in FIG. 1 1, the area of the light-shielding portion 43L of the 1st AF pixel 1 1a and the 2nd AF pixel 12a is small, and the area of the light-shielding portion 43R is large. As shown in FIG. 1 1, Figure 6 As shown in FIG. 1 1, Figure 7 ​In the illustrated first AF pixel 11 c and second AF pixel 12 c , the light shielding portion 43L has a large area, and the light shielding portion 43R has a small area. Figure 7 The first AF pixel 11b and the second AF pixel 12b shown are Figure 6 The area of ​​the light shielding portion 43L is the same as the area of ​​the light shielding portion 43R.

[0086] The right end (end in the +X direction) of the light shielding portion 43L of the first AF pixel 11a is offset in the +X direction by an amount d4 relative to the optical axis OA2 of the microlens 44. The left end (end in the −X direction) of the light shielding portion 43R of the second AF pixel 12a is offset in the +X direction by an amount d4 relative to the optical axis OA2 of the microlens 44.

[0087] The second and third AF pixel pairs differ from the first AF pixel pair in their offset amounts. The offset d5 between the first and second AF pixel 11b, 12b, of the second AF pixel pair is greater than the offset d4 between the first and second AF pixel 11a, 12a, of the first AF pixel pair. The offset d6 between the first and second AF pixel 11c, 12c, of the third AF pixel pair is greater than the offset d5 between the first and second AF pixel 11b, 12b, of the second AF pixel pair. In other words, d4 < d5 < d6.

[0088] like Figure 5 、 Figure 6 as well as Figure 7 As shown, the amount of misalignment between the line passing through the center of the photoelectric converter 42 and the optical axis OA2 of the microlens 44 varies depending on the image height. The higher the image height, the greater the misalignment, while the lower the image height, the smaller the misalignment. At high image heights, light that has passed through the imaging optical system 31 is incident on the microlens 44 at an angle greater than 0° relative to the optical axis OA2 of the microlens 44. Therefore, the greater the angle of incidence of the light on the microlens 44, the greater the misalignment. Light that has entered the microlens 44 at an angle greater than 0° relative to the optical axis OA2 of the microlens 44 is deflected from the optical axis OA2 of the microlens in the +X or -X direction and converges. The line passing through the center of the photoelectric converter 42 is deflected from the optical axis OA2 of the microlens 44, causing the light incident on the microlens 44 to converge onto a line passing through the center of the photoelectric converter 42. In other words, light that has passed through the imaging optical system 31 is converged onto a line passing through the center of the photoelectric converter 42. This can increase the amount of light that passes through the imaging optical system 31 and enters the photoelectric conversion section 42 .

[0089] like Figure 5 、 Figure 6 as well as Figure 7As shown, the areas of the light-shielding portions 43 differ according to the AF pixel pairs. As described above, the exit pupil distance of the photographing optical system 31 differs according to the type of the interchangeable lens 3. Therefore, the first AF pixel pair, the second AF pixel pair, and the third AF pixel pair each have light-shielding portions 43 with different areas for accurately detecting the defocus amount with different exit pupil distances. In addition, the area of the light-shielding portion 43L and the area of the light-shielding portion 43R of the first AF pixel pair differ according to the position (image height) at which the first AF pixel pair is disposed. As described above, the exit pupil distance of the photographing optical system 31 differs according to the image height. Therefore, the first AF pixel pair has light-shielding portions 43L and 43R with areas that vary according to the image height for accurately detecting the defocus amount with different exit pupil distances. The third AF pixel pair is the same as the first AF pixel pair. Thus, the focus detection unit 215 can accurately detect the defocus amount with different exit pupil distances. That is, even if the image height or the type of the interchangeable lens changes, the focus detection unit 215 can accurately detect the defocus amount.

[0090] Therefore, the more the small region 110a of (b) is apart from the optical axis of the microlens 44 in the +X direction, the larger the misalignment amount is. When the misalignment amounts of the first to third AF pixel pairs for the three regions with image heights of Ha, Hb, and Hc (Ha Figure 2 Therefore, the more the small region 110a of (b) is apart from the optical axis of the microlens 44 in the +X direction, the larger the misalignment amount is. When the misalignment amounts of the first to third AF pixel pairs for the three regions with image heights of Ha, Hb, and Hc (Ha Figure 7 The configuration shown in (c) has a larger misalignment amount d1 of the first AF pixel pair in the small region 110c than Figure 6 The configuration shown in (c) has a larger misalignment amount d1 of the first AF pixel pair in the small region 110c than Figure 7 The configuration shown in (c) has a larger misalignment amount d1 of the first AF pixel pair in the small region 110c than Figure 6 The configuration shown in (c) has a larger misalignment amount d1 of the first AF pixel pair in the small region 110c than

[0091] The first to third AF pixel pairs disposed in the small region 110b apart from the small region 110a of (b) in the -X direction have a larger misalignment amount than Figure 2 The first to third AF pixel pairs disposed in the small region 110b apart from the small region 110a of (b) in the -X direction have a larger misalignment amount than Figure 6The same offset amount as the offset amounts d1 to d3 is given in the direction opposite to the offset direction shown. Figure 2 In the first to third AF pixel pairs of the focus detection area 100b of (a), Figure 7 The same shift amounts as shift amounts d4 to d6 are applied in the direction opposite to the shift direction shown. The shift amounts of the first to third AF pixel pairs arranged apart in the -X direction from the small area 110a also increase as the image height increases.

[0092] As described above, the first through third AF pixel pairs have different amounts of misalignment. Therefore, in a plane intersecting the direction of light incidence, the light-receiving areas of the photoelectric converters 42 of the first through third AF pixel pairs differ from one another, and the light-receiving areas of the photoelectric converters 42 of the second AF pixels 12a through 12c differ from one another. Thus, in this embodiment, the light-receiving areas of the photoelectric converters 42 of the first through third AF pixel pairs differ, enabling pupil division corresponding to different angles of incidence. This enables the focus detection unit 215 to accurately detect the amount of defocus.

[0093] Next, an example of a method for determining the amount of shift between the first to third AF pixel pairs in the focus detection area 100 will be described. Figure 8 In FIG. 1 , the position of the small area 110 at the image height Hd from the position 0 (the center of the imaging surface 22a) where the optical axis OA1 of the imaging optical system 31 intersects the imaging surface 22a of the imaging element 22 is indicated by 110α. A first reference exit pupil EP1, a second reference exit pupil EP2, and a third reference exit pupil EP3 are set on the optical axis OA1 of the imaging optical system 31. The second reference exit pupil EP2 is located closer to the imaging surface 22a than the first reference exit pupil EP1 and further to the +Z direction side than the first reference exit pupil EP1. The third reference exit pupil EP3 is located closer to the imaging surface 22a than the second reference exit pupil EP2 and further to the +Z direction side than the second reference exit pupil EP2.

[0094] The distance between the first reference exit pupil EP1 and the imaging plane 22a is referred to as a first reference exit pupil distance Po1, the distance between the second reference exit pupil EP2 and the imaging plane 22a is referred to as a second reference exit pupil distance Po2, and the distance between the third reference exit pupil EP3 and the imaging plane 22a is referred to as a third reference exit pupil distance Po3. Furthermore, Po1>Po2>Po3.

[0095] exist Figure 8In FIG. 1 , L1 represents the principal ray of the light beam that passes through the first reference exit pupil EP1 and enters the AF pixel in the small area 110 at position 110α. L2 represents the principal ray of the light beam that passes through the second reference exit pupil EP2 and enters the AF pixel in the small area 110 at position 110α. L3 represents the principal ray of the light beam that passes through the third reference exit pupil EP3 and enters the AF pixel in the small area 110 at position 110α.

[0096] exist Figure 8 In the figure, when θ1 is set as the incident angle of the main light ray L1 to the AF pixel, the offset amount of the first AF pixel pair in the small area 110 of the image height Hd is determined based on the incident angle θ1. Similarly, when θ2 and θ3 are set as the incident angles of the main light rays L2 and L3 to the AF pixel, respectively, the offset amounts of the second AF pixel pair and the third AF pixel pair in the small area 110 of the image height Hd are determined based on the incident angles θ2 and θ3, respectively. As mentioned above, the larger the incident angle, the larger the offset amount. In addition, except for the position where the image height is 0 (position 0), the longer the exit pupil distance, the smaller the incident angle, so θ1<θ2<θ3. Therefore, Figure 6 The shift amounts d1, d2, and d3 of the first, second, and third AF pixel pairs shown in (a) to (c) satisfy d1 < d2 < d3. Figure 7 The shift amounts d4, d5, and d6 of the first AF pixel pair, the second AF pixel pair, and the third AF pixel pair shown in (a) to (c) satisfy d4<d5<d6.

[0097] In this way, the offset amount of the first AF pixel pair relative to the first reference exit pupil EP1 (first reference exit pupil distance Po1) is determined. Similarly, the offset amount of the second AF pixel pair relative to the second reference exit pupil EP2 (second reference exit pupil distance Po2) is determined, and the offset amount of the third AF pixel pair relative to the third reference exit pupil EP3 (third reference exit pupil distance Po3) is determined.

[0098] Next, the relationship between the exit pupil distance of the photographing optical system 31 and the first to third AF pixel pairs will be described. Figure 8In the present invention, a first threshold value Th1 related to the exit pupil distance is set at the midpoint between the first reference exit pupil EP1 and the second reference exit pupil EP2, and a second threshold value Th2 related to the exit pupil distance is set at the midpoint between the second reference exit pupil EP2 and the third reference exit pupil EP3. The region where the exit pupil distance is greater than or equal to the first threshold value Th1 is defined as the first exit pupil distance range R1, the region where the exit pupil distance is between the first threshold value Th1 and the second threshold value Th2 is defined as the second exit pupil distance range R2, and the region where the exit pupil distance is less than or equal to the second threshold value Th2 is defined as the third exit pupil distance range R3.

[0099] The pixel selection unit 213 selects a first AF pixel pair when the exit pupil distance of the imaging optical system 31 is greater than or equal to the first threshold value Th1, that is, when it falls within the first exit pupil distance range R1. The pixel selection unit 213 selects a second AF pixel pair when the exit pupil distance of the imaging optical system 31 is between the first threshold value Th1 and the second threshold value Th2, that is, when it falls within the second exit pupil distance range R2. The pixel selection unit 213 selects a third AF pixel pair when the exit pupil distance of the imaging optical system 31 is less than or equal to the second threshold value Th2, that is, when it falls within the third exit pupil distance range R3.

[0100] As described above, the pixel selection unit 213 selects an appropriate AF pixel pair from the first to third AF pixel pairs according to whether the exit pupil distance of the photographing optical system belongs to the first to third exit pupil distance ranges R1 to R3 .

[0101] Next, the optical characteristics of the imaging optical system 31 of the interchangeable lens 3 , that is, the optical characteristics in which the exit pupil distance thereof changes according to the image height, will be described. Figure 9 Indicates installation on Figure 1 The optical characteristic of the interchangeable lens 3 of the camera body 2 that the exit pupil distance changes according to the image height. Figure 9 In the figure, the horizontal axis represents the exit pupil distance Po, and the vertical axis represents the image height H. Figure 9 (a), (b), (c), and (d) show the optical characteristics of different types of interchangeable lenses. Figure 9 The optical characteristics of the photographing optical system 31 of the interchangeable lens 3 shown in (a) are represented by an optical characteristic curve 200a. As the image height H increases, the exit pupil distance Po decreases. Figure 9 The optical characteristic curve 200a of (a) shows that when the image height is zero, the exit pupil distance is Poa, and as the image height H increases, the exit pupil distance gradually decreases. At the maximum image height Hmax, the exit pupil distance becomes (Poa-Δp1).

[0102] Figure 9 The optical characteristic of the photographing optical system 31 of the interchangeable lens 3 shown in (b) of FIG. 2 is indicated by an optical characteristic curve 200b. As the image height H becomes larger, the exit pupil distance Po becomes larger. Figure 9 The optical characteristic curve 200b of (b) of FIG. 2 indicates that the exit pupil distance is Pob at the image height of zero, and as the image height H becomes larger, the exit pupil distance gradually becomes larger, and at the maximum image height Hmax, the exit pupil distance becomes (Pob + Δp2).

[0103] In the following description, an optical characteristic curve in which the exit pupil distance Po becomes smaller as the image height H becomes larger, like the optical characteristic curve 200a, is referred to as a negative optical characteristic curve. In addition, an optical characteristic curve in which the exit pupil distance Po also becomes larger as the image height H becomes larger, like the optical characteristic curve 200b, is referred to as a positive optical characteristic curve.

[0104] Figure 9 The photographing optical system 31 of the interchangeable lens 3 shown in (c) of FIG. 2 is a photographing optical system whose optical characteristic curve is different, that is, changes, depending on the position of the focusing lens 31b. This photographing optical system 31 exhibits an optical characteristic curve 200c when the focusing lens 31b is positioned at a first position, and an optical characteristic curve 200d when the focusing lens 31b is positioned at a second position. The first position and the second position of the focusing lens 31b are any positions between the infinity position and the closest position including the infinity position and the closest position of the focusing lens 31b. In addition, the infinity position of the focusing lens 31b is a position at which a subject at an infinite distance is focused, and the closest position is a position at which a subject at a closest distance is focused. Figure 1 In (c) of FIG. 2, the optical characteristic curve 200c indicates the optical characteristic of the photographing optical system 31 when the focusing lens 31b is positioned at the first position. The optical characteristic curve 200c indicates that the exit pupil distance is Poc at the image height of zero, and as the image height H becomes larger, the exit pupil distance gradually becomes smaller, and at the maximum image height Hmax, the exit pupil distance becomes (Poc - Δp3). The optical characteristic curve 200d indicates the optical characteristic of the photographing optical system 31 when the focusing lens 31b is positioned at the second position. The optical characteristic curve 200d indicates that the exit pupil distance is Pod at the image height of zero, and as the image height H becomes larger, the exit pupil distance gradually becomes larger, and at the maximum image height Hmax, the exit pupil distance becomes (Pod + Δp4).

[0105] Figure 9 In (c) of FIG. 2, the optical characteristic curve 200c indicates the optical characteristic of the photographing optical system 31 when the focusing lens 31b is positioned at the first position. The optical characteristic curve 200c indicates that the exit pupil distance is Poc at the image height of zero, and as the image height H becomes larger, the exit pupil distance gradually becomes smaller, and at the maximum image height Hmax, the exit pupil distance becomes (Poc - Δp3). The optical characteristic curve 200d indicates the optical characteristic of the photographing optical system 31 when the focusing lens 31b is positioned at the second position. The optical characteristic curve 200d indicates that the exit pupil distance is Pod at the image height of zero, and as the image height H becomes larger, the exit pupil distance gradually becomes larger, and at the maximum image height Hmax, the exit pupil distance becomes (Pod + Δp4).

[0106] In addition, in (c) of FIG. 2, the exit pupil distance Poc of the optical characteristic curve 200c at the image height of zero is smaller than the exit pupil distance Pod of the optical characteristic curve 200d at the image height of zero. Figure 9 ​In (c), the optical characteristic curve 200c when the focus lens 31b is in the first position is shown as a negative optical characteristic curve, and the optical characteristic curve 200d when the focus lens 31b is in the second position is shown as a positive optical characteristic curve. However, there are also interchangeable lenses 3 having optical characteristic curves 200c and 200d that have both positive optical characteristics or both negative optical characteristics.

[0107] Figure 9 The photographing optical system 31 of the interchangeable lens 3 shown in (d) is a graph whose optical characteristic curve is obtained according to the focal length ( Figure 1 The photographing optical system 31 exhibits an optical characteristic curve 200e when the focal length is f1 and an optical characteristic curve 200f when the focal length is f2.

[0108] exist Figure 9 In (d), optical characteristic curve 200e represents the optical characteristics of the imaging optical system 31 when the focal length is f1. Optical characteristic curve 200e shows that at image height zero, the exit pupil distance is Poe. As the image height H increases, the exit pupil distance gradually decreases, reaching (Poe - Δp5) at the maximum image height Hmax. Optical characteristic curve 200f represents the optical characteristics of the imaging optical system 31 when the focal length is f2. Optical characteristic curve 200f shows that at image height zero, the exit pupil distance is Pof. As the image height H increases, the exit pupil distance gradually increases, reaching (Pof + Δp6) at the maximum image height Hmax.

[0109] In addition, Figure 9 In (d), the optical characteristic curve 200e when the focal length is f1 is shown as a negative optical characteristic curve, and the optical characteristic curve 200f when the focal length is f2 is shown as a positive optical characteristic curve. However, there are also interchangeable lenses 3 having optical characteristics curves 200e and 200f that are both positive or both negative.

[0110] In the above description, the exit pupil distance Po at the image height H is the distance of the exit pupil of the imaging optical system 31 as viewed from the imaging surface 22a at the image height H. In other words, the exit pupil distance Po at the image height H is the distance of the exit pupil of the imaging optical system 31 (the distance from the imaging surface 22a) that a light beam that has passed through the imaging optical system 31 and is incident on the imaging surface 22a at the position of the image height H passes through.

[0111] Figure 10 The relationship between the image height H and the exit pupil distance Po is shown. Figure 10In the image capturing optical system 31, the light beam passing through the exit pupil EPa (exit pupil distance Poa) enters the AF pixel (at the center position 0 (image height is zero) of the imaging surface 22a) Figure 10 (A microlens 44 is shown in the figure to represent the AF pixel.) The exit pupil distance Poa of the exit pupil EPa is the exit pupil distance relative to the exit pupil EPa with an image height of zero.

[0112] In addition, the light beam that has passed through the exit pupil EPb of the photographing optical system 31 is incident on the AF pixel located at the image height He (at Figure 10 ( ) The microlens 44 is shown in the figure to represent the AF pixel. The exit pupil distance (Poa-Δp) of the exit pupil EPb is the exit pupil distance of the exit pupil EPb relative to the image height H.

[0113] Here, the relationship between the optical characteristics of each interchangeable lens 3 and the above-mentioned formula (1) is described. Po(H)=h4×H in the above-mentioned formula (1) 4 +h2×H 2 +Co is Figure 9 (a)~ Figure 9 The function that approximates the optical characteristic curves 200a, 200b, 200c, 200d, 200e, 200f, etc. shown in (d) is used. Figure 9 The optical characteristic curve 200a of (a) is obtained by setting the constant term Co of the equation (1) to Figure 9 The exit pupil distance Poa at which the image height of (a) is zero is set, and the coefficients h4 and h2 are set to the coefficients h4a and h2a corresponding to the curve of the optical characteristic curve 200a, thereby performing approximation by the operation of formula (1). Figure 9 The interchangeable lens 3 having the optical characteristics of (a) stores the constant term Poa and the coefficients h4a and h2a as lens information in the lens memory 33 as described above.

[0114] Likewise, having Figure 9 The interchangeable lens 3 having the optical characteristics of (b) stores the constant term Pob and the coefficients h4b and h2b that determine the operation of the equation (1) for approximating the optical characteristics curve 200b in the lens memory 33 as lens information.

[0115] in addition, Figure 9The interchangeable lens 3 of (c) has an optical characteristic whose curve changes according to the position of the focusing lens 31b. The interchangeable lens 3 stores the constant term Co and the coefficients h4, h2 of the operation of the formula (1) approximating the optical characteristic curve for each position of the focusing lens 31b in the lens memory 33. The range (between the infinity position and the closest position) in which the focusing lens 31b is moved is divided into a plurality of zones Z1 to Zn, and one optical characteristic curve representing the zone (range) is determined for each zone Z1 to Zn. For example, the optical characteristic curve when the focusing lens 31b is at the central position of one zone is taken as the optical characteristic curve representing the zone.

[0116] The optical characteristic curve representing the zone Zk is set as the optical characteristic curve Zk (k = 1, 2,..., n). As for the operation of the formula (1) approximating the representative optical characteristic curve Z1 of the zone Z1, the constant term Co and the coefficients h4, h2 are set as Poz1, h4z1, h2z1. As for the operation of the formula (1) approximating the optical characteristic curve Z2 of the zone Z2, the constant term Co and the coefficients h4, h2 are set as Poz2, h4z2, h2z2, respectively. Hereinafter, the same applies to the operation of the formula (1) approximating the optical characteristic curve Zn of the zone Zn, and the constant term Co and the coefficients h4, h2 are set as Pozn, h4zn, h2zn, respectively. Figure 11 The zones and the constant terms and the coefficients of the operation of approximating the optical characteristic curve representing the zone are shown. The interchangeable lens 3 stores the zones Z1 to Zn and the constant terms Poz1 to Pozn and the coefficients h4z1 to h4zn, h2z1 to h2zn as lens information in the lens memory 33. Figure 11 The zones Z1 to Zn and the constant terms Poz1 to Pozn and the coefficients h4z1 to h4zn, h2z1 to h2zn shown are stored as lens information in the lens memory 33.

[0117] Figure 9 The interchangeable lens 3 of (d) is a zoom lens having an optical characteristic whose curve changes according to the focal length. The interchangeable lens 3 stores the constant term Co and the coefficients h4, h2 of the operation of the formula (1) approximating the optical characteristic curve for each focal length in the lens memory 33. The range between the maximum focal length and the minimum focal length of the zoom lens set by the zoom lens 31a is divided into a plurality of zones W1 to Wn, and one optical characteristic curve representing the zone is determined for each zone W1 to Wn. For example, the optical characteristic curve at the focal length in the middle of one zone is taken as the optical characteristic curve representing the zone. Figure 1 The zones and the constant terms and the coefficients of the operation of approximating the optical characteristic curve representing the zone are shown. The interchangeable lens 3 stores the zones W1 to Wn and the constant terms Pw1 to Pwn and the coefficients h4w1 to h4wn, h2w1 to h2wn as lens information in the lens memory 33.

[0118] The optical characteristic curve representing interval Wk is set to optical characteristic curve Wk (k = 1, 2, ..., n). Regarding the operation of formula (1) for approximating the optical characteristic curve W1 of interval W1, its constant term Co and coefficients h4 and h2 are set to Pow1, h4w1, and h2w1, respectively. Regarding the operation of formula (1) for approximating the optical characteristic curve W2 of interval W2, its constant term Co and coefficients h4 and h2 are set to Pow2, h4w2, and h2w2, respectively. Similarly, regarding the operation of formula (1) for approximating the optical characteristic curve Wn of interval Wn, its constant term Co and coefficients h4 and h2 are set to Pown, h4wn, and h2wn, respectively. Figure 12 These intervals and the constant terms and coefficients for approximating the optical characteristic curve representing the interval are shown. Figure 12 The relationship between the intervals W1 to Wn, the constant terms Pow1 to Pown, and the coefficients h4w1 to h4wn and h2w1 to h2wn is stored in the lens memory 33 as lens information.

[0119] also, Figure 9 While the interchangeable lens 3 in (d) is a zoom lens having an optical characteristic curve that changes depending on the focal length, the other zoom lenses have optical characteristics that change depending on the focal length and, further, also change depending on the position of the focus lens 31b. In other words, the optical characteristic curves of the other zoom lenses change depending on both the position (focal length) of the zoom lens 31a and the position of the focus lens 31b.

[0120] Next, express Figure 9 The optical characteristics of the interchangeable lens 3 are shown in the optical characteristic curve. Figure 8 The relationship between the first exit pupil distance range R1 to the third exit pupil distance range R3 will be described. Figure 13 Expressed with Figure 8 The first threshold value Th1 and the second threshold value Th2 related to the exit pupil distance, the first exit pupil distance range R1 to the third exit pupil distance range R3, and Figure 9 The optical characteristic curves shown in the example. Figure 13 , the entire curve of the optical characteristic curve 200g, that is, the exit pupil distance from the image height zero to the maximum image height Hmax, is within the second exit pupil distance range R2. When the interchangeable lens 3 having such an optical characteristic curve 200g is mounted on the camera body 2, the pixel selection unit 213 selects the second AF pixel pair regardless of the focus detection area 100 of the image height H set by the area setting unit 211.

[0121] The exit pupil distance from the image height of zero to the image height Hf of the optical characteristic curve 200h belongs to the 2nd exit pupil distance range R2, but the exit pupil distance from the image height Hf to the maximum image height Hmax belongs to the 1st exit pupil distance range R1. The pixel selection section 213 selects the 2nd AF pixel pair in a case where the area setting section 211 sets the focus detection area 100 with the image height of Hf or less, and selects the 1st AF pixel pair in a case where the area setting section 211 sets the focus detection area with the image height larger than Hf.

[0122] The exit pupil distance from the image height of zero to the image height Hg of the optical characteristic curve 200i belongs to the 3rd exit pupil distance range R3, but the exit pupil distance from the image height Hg to the maximum image height Hmax belongs to the 2nd exit pupil distance range R2. The pixel selection section 213 selects the 3rd AF pixel pair in a case where the area setting section 211 sets the focus detection area 100 with the image height of Hg or less, and selects the 2nd AF pixel pair in a case where the area setting section 211 sets the focus detection area with the image height larger than Hg.

[0123] Further, as described above, in a case where a plurality of focus detection areas 100 are set by the area setting section 211, the pixel selection section 213 selects the same kind of AF pixel pair in each of the selected focus detection areas 100. In this case, the pixel selection section 213 selects the AF pixel pair based on the position of the focus detection area 100 farthest from the optical axis OA1 of the photographing optical system 31 (the highest image height H) among the plurality of selected focus detection areas 100. In the present embodiment, the pixel selection section 213 selects the AF pixel pair as described above in accordance with the image height of the focus detection area 100 with the highest image height among the plurality of selected focus detection areas 100. The pixel selection section 213 also selects the same kind of AF pixel pair as selected in the focus detection area 100 with the highest image height among the plurality of selected focus detection areas 100 in the other focus detection areas 100.

[0124] Reference Signs List Figure 14 and Figure 15 The circuit structure and operation of the imaging element 22 related to the 1st embodiment will be described. Figure 14 is a view showing the structure of the pixel of the imaging element 22 related to the 1st embodiment. The pixel 13 has a photoelectric conversion section 42, a transfer section 52, a reset section 53, a floating diffusion section (FD) 54, an amplification section 55, and a selection section 56. The photoelectric conversion section 42 is a photodiode PD that converts the incident light into electric charges and accumulates the electric charges obtained by the photoelectric conversion.

[0125] The transfer section 52 is constituted by a transistor Ml controlled by the signal TX, and transfers the electric charge obtained by photoelectric conversion in the photoelectric conversion section 42 to the FD 54. The transistor Ml is a transfer transistor. The capacitance C of the FD 54 accumulates (holds) the electric charge transferred to the FD 54.

[0126] The amplification section 55 outputs a signal based on the electric charge accumulated in the capacitance C of the FD 54. The amplification section 55 and the selection section 56 constitute an output section that generates and outputs a signal based on the electric charge generated by the photoelectric conversion section 42.

[0127] The reset section 53 is constituted by a transistor M2 controlled by the signal RST, and discharges the electric charge accumulated in the FD 54 to reset the voltage of the FD 54. The transistor M2 is a reset transistor.

[0128] The selection section 56 is constituted by a transistor M4 controlled by the signal SEL, and electrically connects or cuts off the amplification section 55 from the vertical signal line 60. The transistor M4 is a selection transistor.

[0129] As described above, the electric charge obtained by photoelectric conversion in the photoelectric conversion section 42 is transferred to the FD 54 by the transfer section 52. Also, a signal corresponding to the electric charge transferred to the FD 54 is output to the vertical signal line 60. The pixel signal is an analog signal generated based on the electric charge obtained by photoelectric conversion by the photoelectric conversion section 42. The signal output from the imaging pixel 13 is output to the body control section 210 after being converted to a digital signal.

[0130] Further, in the present embodiment, the circuit structure of the first AF pixel 11 (11a to 11c) and the second AF pixel 12 (12a to 12c) is the same as that of the imaging pixel 13. The signals output from the first AF pixel 11 and the second AF pixel 12 are output to the body control section 210 as a pair of signals (first signal Sigl and second signal Sig2) used in focus detection after being converted to digital signals.

[0131] Figure 15 is a diagram showing a structure example of an imaging element according to the first embodiment. The imaging element 22 has a plurality of imaging pixels 13, a first AF pixel 11 and a second AF pixel 12, a vertical control section 70, and a plurality of column circuit sections 80. Further, in Figure 15 In the present embodiment, for simplicity of explanation, only 128 pixels of 8 pixels in the row direction (±X direction) x 16 pixels in the column direction (±Y direction) are shown. In Figure 15In the present embodiment, the pixel at the upper left corner is set as the photographing pixel 13 (1, 1) of the first row and the first column, and the pixel at the lower right corner is set as the photographing pixel 13 (16, 8) of the 16th row and the 8th column. The imaging element 22 is provided with a plurality of vertical signal lines 60 (vertical signal line 60a to vertical signal line 60h). The plurality of vertical signal lines 60 are connected to the pixel columns (first column to eighth column) that are the columns of the plurality of pixels arranged in the column direction, that is, the vertical direction. The vertical signal lines 60a, 60c, 60e, and 60g are connected to the plurality of photographing pixels 13 arranged in the same column and output the signals of the photographing pixels 13 connected thereto, respectively. The vertical signal lines 60b, 60d, 60f, and 60h are connected to the plurality of photographing pixels 13, the plurality of first AF pixels 11, and the plurality of second AF pixels 12 arranged in the same column and output the signals of the photographing pixels 13, the first AF pixels 11, and the second AF pixels 12 connected thereto, respectively.

[0132] The vertical control section 70 is provided commonly to the plurality of pixel columns. The vertical control section 70 supplies the signals TX, RST, and SEL illustrated in FIG. 6 to each pixel and controls the operation of each pixel. The vertical control section 70 supplies the signals to the gates of the transistors of each pixel and causes the transistors to be in the ON state (connected state, conductive state, short-circuit state) or the OFF state (disconnected state, non-conductive state, open state, open-circuit state). Figure 14

[0133] The column circuit section 80 includes an analog / digital conversion section (AD conversion section) to constitute and outputs the analog signals input from each pixel via the vertical signal line 60 as digital signals. The signals of the pixels converted to the digital signals are input to a signal processing section not illustrated in the drawing, subjected to signal processing such as correlated double sampling, correction of the amount of signal, and the like, and output to the body control section 210 of the camera 1.

[0134] The readout section 214 of the camera 1 controls the vertical control section 70 and performs the first readout mode in which the signals of each pixel are read out by sequentially selecting all the pixel rows and the second readout mode in which the readout of the signals of each pixel of the AF pixel row and the readout of the signals of each pixel of the photographing pixel row are performed separately.

[0135] The vertical control section 70 sequentially selects the plurality of pixel rows to cause the signals to be output from each pixel in the case where the first readout mode is set by the readout section 214. The vertical control section 70 sequentially selects the plurality of pixel rows to cause the signals to be output from each pixel in the case where the second readout mode is set by the readout section 214. Figure 15 ​The 1st shooting pixel row 401, the 2nd shooting pixel row 402, and the AF pixel rows 403a, 404a, 403b, 404b are sequentially selected from the 1st row to the 16th row. The vertical control section 70 causes signals to be output from the pixels of the selected shooting pixel row or AF pixel row to the vertical signal lines 60. The readout section 214 reads out the signals output to the vertical signal lines 60. Hereinafter, one example of the signal readout method in the 1st readout mode will be described.

[0136] First, the vertical control section 70 causes the selection sections 56 of the R pixel 13(1, 1) to the G pixel 13(1, 8) of the pixels of the 1st shooting pixel row 401 as the 1st row to be in the ON state, respectively. The vertical control section 70 causes the selection sections 56 of the pixels of the other rows except the 1st row to be in the OFF state, respectively. Thus, the signals of the R pixel 13(1, 1) to the G pixel 13(1, 8) of the 1st row are each output to the vertical signal line 60a to the vertical signal line 60h via the selection section 56 of each pixel connected thereto. The readout section 214 reads out the signals output from the R pixel 13(1, 1) to the G pixel 13(1, 8) to the vertical signal lines 60.

[0137] Next, the vertical control section 70 causes the selection sections 56 of the G pixel 13(2, 1) to the 1st AF pixel 11a(2, 8) of the pixels of the 1st AF pixel row 403a as the 2nd row to be in the ON state. In addition, the vertical control section 70 causes the selection sections 56 of the pixels of the other rows except the 2nd row to be in the OFF state. Thus, the signals of the G pixel 13(2, 1) to the 1st AF pixel 11a(2, 8) of the 2nd row are each output to the vertical signal line 60a to the vertical signal line 60h. The readout section 214 reads out the signals output from the G pixel 13(2, 1) to the 1st AF pixel 11a(2, 8) of the 2nd row to the vertical signal lines 60.

[0138] Similarly, the vertical control section 70 sequentially selects the pixel rows (1st shooting pixel row 401, 2nd shooting pixel row 402, 1st AF pixel row 403, 2nd AF pixel row 404) from the 3rd row onward one by one in the order of the 3rd row, the 4th row, the 5th row, and the 6th row. The vertical control section 70 causes signals to be output from the pixels of the selected shooting pixel row or AF pixel row to the vertical signal lines 60. The readout section 214 reads out the signals output to the vertical signal lines 60.

[0139] Thus, in the 1st readout mode, the readout section 214 reads out signals from the pixels of all the pixel rows. The signals read out from the pixels are output to the body control section 210 after being subjected to signal processing by the column circuit section 80 or the like.

[0140] When the second readout mode is set by the readout unit 214, the vertical control unit 70 separately outputs the signals of each pixel in the AF pixel row to the vertical signal line 60 and the signals of each pixel in the imaging pixel row to the vertical signal line 60. In this embodiment, the vertical control unit 70 first sequentially selects only the AF pixel row, so that the signals from each pixel in the selected AF pixel row are output to the vertical signal line 60. Then, the vertical control unit 70 sequentially selects the imaging pixel row, so that the signals from each pixel in the selected imaging pixel row are output to the vertical signal line 60. The readout unit 214 first reads only the signals output from each pixel in the AF pixel row to the vertical signal line 60, and then reads the signals output from each pixel in the imaging pixel row to the vertical signal line 60.

[0141] An example of a signal readout method in the second readout mode is described below. Furthermore, the vertical control unit 70 selects an AF pixel row in which the AF pixel pair selected by the pixel selection unit 213 is arranged within one (or more) focus detection areas 100 set by the area setting unit 211. In the example shown below, the pixel selection unit 213 selects the first AF pixel pair based on the exit pupil distance of the photographing optical system 31.

[0142] First, the vertical control unit 70 makes the structure Figure 15 As shown, the selectors 56 of the G pixels 13 (2, 1) through the first AF pixel 11a (2, 8) in the second row of the first AF pixel row 403a are all in the ON state. The vertical control unit 70 turns the selectors 56 of the pixels in rows other than the second row off. Consequently, the signals of each of the G pixels 13 (2, 1) through the first AF pixel 11a (2, 8) are output to the vertical signal lines 60a through 60h connected to the pixels via the selectors 56 of the respective pixels. The readout unit 214 reads the signals output from the G pixels 13 (2, 1) through the first AF pixel 11a (2, 8) to the vertical signal lines 60.

[0143] Next, the vertical control unit 70 makes the structure Figure 15 As shown, the selectors 56 of the G pixels 13 (6, 1) through the second AF pixel 12a (6, 8) in the sixth row of the second AF pixel row 404a are in the ON state. Furthermore, the vertical control unit 70 turns the selectors 56 of the pixels in rows other than the sixth row off. Consequently, the signals of the G pixels 13 (6, 1) through the second AF pixel 12a (6, 8) are output to the vertical signal lines 60a through 60h, respectively. The readout unit 214 reads the signals output from the G pixels 13 (6, 1) through the second AF pixel 12a (6, 8) to the vertical signal lines 60.

[0144] Although not shown, the first AF pixel row 403a and the second AF pixel row 404a are also arranged in multiple rows after the 16th row. The vertical control unit 70 sequentially selects only the first AF pixel row 403a and the second AF pixel row 404a in the column direction (+Y direction). The vertical control unit 70 causes each pixel constituting the selected first AF pixel row 403a and second AF pixel row 404a to output a signal to the vertical signal line 60. The readout unit 214 reads the signals output to the vertical signal line 60 from the G pixel 13, the first AF pixel 11a, and the second AF pixel 12a. The signals sequentially read out from each AF pixel row are subjected to signal processing by the column circuit unit 80 and other means, and then output to the body control unit 210.

[0145] After reading out the signals from each pixel in the AF pixel row, the vertical control unit 70 sequentially selects the imaging pixel row in the column direction (+Y direction). The vertical control unit 70 outputs the signals from each pixel in the selected imaging pixel row to the vertical signal line 60. The readout unit 214 reads out the signals outputted from each pixel in the imaging pixel row to the vertical signal line 60. The vertical control unit 70 outputs the signals from each pixel in the imaging pixel row to the vertical signal line 60. Figure 15 The selectors 56 of the R pixels 13 (1, 1) to the G pixels 13 (1, 8) of the first imaging pixel row 401 are shown as being in the ON state. The vertical control unit 70 turns the selectors 56 of the pixels in rows other than the first row OFF. As a result, the signals of the R pixels 13 (1, 1) to the G pixels 13 (1, 8) are output to the vertical signal lines 60a to 60h, respectively. The readout unit 214 reads the signals output from the R pixels 13 (1, 1) to the G pixels 13 (1, 8) to the vertical signal lines 60.

[0146] Next, the vertical control unit 70 makes the structure Figure 15 The selectors 56 of the R pixels 13 (3, 1) to the G pixels 13 (3, 8) of the first imaging pixel row 401 (the third row) are shown to be in the ON state. Furthermore, the vertical control unit 70 turns the selectors 56 of the pixels in rows other than the third row to the OFF state. As a result, the signals of the R pixels 13 (3, 1) to the G pixels 13 (3, 8) are output to the vertical signal lines 60a to 60h, respectively. The readout unit 214 reads the signals output from the R pixels 13 (3, 1) to the G pixels 13 (3, 8) to the vertical signal lines 60.

[0147] Furthermore, the vertical control unit 70 is configured Figure 15The selection section 56 of the G pixel 13(4, 1) to the B pixel 13(4, 8) of the 1st pixel row 402 of the 4th row is in the ON state as illustrated. The selection section 56 of the pixels of the rows other than the 4th row is in the OFF state by the vertical control section 70. Thereby, the signals of the G pixel 13(4, 1) to the B pixel 13(4, 8) are respectively output to the vertical signal lines 60a to 60h. The readout section 214 reads out the signals output from the G pixel 13(4, 1) to the B pixel 13(4, 8) to the vertical signal lines 60.

[0148] Similarly, the selection of the pixel rows (1st pixel row 401, 2nd pixel row 402) is sequentially performed one by one from the 5th row onward. The vertical control section 70 causes the signals to be output from the respective pixels constituting the selected 1st pixel row 401, 2nd pixel row 402 to the vertical signal lines 60. The readout section 214 reads out the signals output from the R pixel 13, G pixel 13, and B pixel 13 to the vertical signal lines 60. The signals sequentially read out from the respective pixel rows are read out by the body control section 210 after the signal processing by the column circuit section 80 and the like.

[0149] Thus, in the 2nd readout mode, the readout section 214 controls the vertical control section 70 to read out the signals from the respective pixels of the AF pixel rows prior to the pixel rows. Therefore, the 1st signal Sig1 and the 2nd signal Sig2 of the AF pixel pair based on the exit pupil distance selection of the photographing optical system 31 can be read out at high speed, and the time required for the focus adjustment can be shortened. Further, the signals of the respective pixels of the AF pixel rows are read out separately from the signals of the respective pixels of the pixel rows by the readout section 214, and thus the signals used in the focus detection can be efficiently obtained, and the burden of the signal processing for the AF can be alleviated. Further, the camera 1 according to the present embodiment reads out the 1st signal Sig1 and the 2nd signal Sig2 of the AF pixel pair based on the exit pupil distance selection of the photographing optical system 31 to perform the focus detection processing. Therefore, the focus detection with high precision can be achieved.

[0150] Further, the readout section 214 can also read out the signals from the respective pixels of the pixel rows prior to the AF pixel rows in the case where the 2nd readout mode is set. In this case as well, the signals of the AF pixel pair based on the exit pupil distance selection of the photographing optical system 31 are read out to perform the focus detection processing, and thus the focus detection with high precision can be achieved. Further, the signals of the respective pixels of the AF pixel rows can be read out separately from the signals of the respective pixels of the pixel rows, and the burden of the signal processing for the AF can be alleviated.

[0151] In addition, the readout section 214 can perform sparse readout that reads out signals from the pixels of the specific row and column of the plurality of pixels sparsely in the case where the second readout mode is set to read out signals from the pixels of the first and second shooting pixel rows 401 and 402. In the case of performing sparse readout, the readout section 214 selects the pixels of the specific row and column of the plurality of pixels and reads out signals from the selected pixels. The readout section 214 can read out signals at high speed by skipping the signals of the pixels of the specific row and column by controlling the vertical control section 70. In this case, the readout section 214 can perform readout of signals from the AF pixel rows before readout of signals from the shooting pixel rows by performing the second readout mode, and can perform readout of signals from the shooting pixel rows at high speed. Therefore, the readout section 214 can perform focus detection at high speed and can perform shooting at high speed by performing the second readout mode in the case of performing display of a live view image or shooting of a moving image. Further, the readout section 214 can perform readout by performing addition operation on the signals of the plurality of pixels.

[0152] According to the above-described embodiments, the following advantageous effects can be obtained.

[0153] (1) The focus detection device includes a shooting section (shooting element 22) that has first and second pixels (AF pixels) that receive light transmitted through an optical system (shooting optical system 31) and output signals used in focus detection, and a third pixel (shooting pixel) that receives light transmitted through the optical system and outputs a signal used in image generation; an input section (body control section 210) that is input with information related to the optical system; a selection section (pixel selection section 213) that selects at least one of the first and second pixels based on the information input to the input section; a readout section (readout section 214) that reads out at least one of the signals of the first and second pixels at a timing different from the signal of the third pixel based on the selection of the selection section; and a focus detection section 215 that performs focus detection based on at least one of the signals of the first and second pixels read out by the readout section. In the present embodiment, the readout section 214 reads out signals from the pixels of the AF pixel rows before the pixels of the shooting pixel rows. Therefore, the focus detection device can read out signals of the AF pixel pairs at high speed and can perform focus adjustment at high speed. In addition, the focus detection device can read out signals of the pixels of the AF pixel rows separately from signals of the pixels of the shooting pixel rows, and can reduce the burden of signal processing for AF. In addition, the focus detection section 215 performs focus detection processing using signals output from the AF pixel pairs selected based on the exit pupil distance of the shooting optical system 31. Therefore, the focus detection device can perform focus detection with high precision.

[0154] Modifications such as the following are also within the scope of the present application, and one or more of the modifications can also be combined with the above-described embodiments.

[0155] (Modification 1)

[0156] In the first embodiment, the reference exit pupil uses three reference exit pupils (first exit pupil EP1 to third exit pupil EP3), but it can be two reference exit pupils or four or more reference exit pupils.

[0157] (Modification 2)

[0158] The method of finding the exit pupil distance corresponding to the image height is not limited to the method of using the above-described equation (1). For example, instead of equation (1), an operation equation using the cube of the image height can be applied. Further, instead of the operation equation, information (table) indicating the relationship between the image height and the exit pupil distance can be used.

[0159] (Modification 3)

[0160] In the first embodiment, the example in which the information about the exit pupil distance is input from the interchangeable lens 3 to the camera body 2 by being pre-stored in the lens memory 33 or the like was described. However, the information of the exit pupil distance can be input from the camera body 2 from outside the interchangeable lens 3. For example, the body memory 23 can be pre-stored with the information of the exit pupil distance, and the body control section 210 can acquire the information of the exit pupil distance from the body memory 23. In addition, the camera body 2 can acquire the information of the exit pupil distance from a storage medium or from an external device through wired or wireless communication. Further, the information about the exit pupil distance can be information about the exit pupil distance corresponding to one image height.

[0161] (Modification 4)

[0162] In the first embodiment, as the information about the exit pupil distance, the parameters (h4), (h2), and the constant term Co used in the calculation of the exit pupil distance Po(H) were described as examples. However, the camera body 2 can acquire the value Po(H) of the exit pupil distance corresponding to the image height itself from the interchangeable lens 3, a storage medium, or the like as the information about the exit pupil distance.

[0163] (Modification 5)

[0164] In the above-described embodiment, the example in which the first to third AF pixel pairs in which the shift amounts of the color filters 51 are different from each other are arranged in the imaging element 22 as the plurality of kinds of AF pixel pairs is described. However, the plurality of kinds of AF pixel pairs in which the arrangement positions of the light-shielding portions between the color filters 51 and the photoelectric conversion portions 42 are different from each other can be arranged in the imaging element 22. Figure 16 is a view that shows a configuration example of the AF pixels of the imaging element 22 to which the modification relates. Further, the same reference numerals are attached to the same or equivalent portions as those of the above-described embodiment in the view.

[0165] The light-shielding portion 43L of the first AF pixel 11a is arranged at a position that is a predetermined interval h1 from the photoelectric conversion portion 42 between the color filter 51 and the photoelectric conversion portion 42. The light-shielding portion 43L of the first AF pixel 11b is arranged at a position that is a predetermined interval h2 from the photoelectric conversion portion 42 between the color filter 51 and the photoelectric conversion portion 42. Further, the light-shielding portion 43L of the first AF pixel 11c is arranged at a position that is a predetermined interval h3 from the photoelectric conversion portion 42 between the color filter 51 and the photoelectric conversion portion 42. The interval h2 is smaller than the interval h1 and larger than the interval h3. That is, h1 > h2 > h3. In this way, the arrangement positions of the light-shielding portions 43L of the first AF pixels 11a, 11b, and 11c are different. Further, the arrangement positions of the light-shielding portions 43R of the second AF pixels 12a, 12b, and 12c that constitute the other sides of the AF pixel pairs are different. Thus, the first to third AF pixel pairs can perform pupil division in correspondence with different incident angles as in the case of the above-described embodiment.

[0166] (Modification 6)

[0167] In the first embodiment, the example in which one photoelectric conversion portion is arranged in one pixel is described, but the structure of the pixel can be such that two or more photoelectric conversion portions are provided in each pixel.

[0168] (Modification 7)

[0169] Figure 17 is a view that shows a configuration example of the AF pixels of the imaging element 22 to which the modification relates. As one example, Figure 17 is a view that shows a configuration example of the AF pixels of the imaging element 22 to which the modification relates. As one example, Figure 2 is a view that shows a cross-sectional view of the three kinds of AF pixel pairs in a portion of the focus detection area 100c of Figure 17The three types of AF pixels of (a) to (c) each have a microlens 44, and a first photoelectric conversion section 42a and a second photoelectric conversion section 42b that photoelectrically convert light transmitted through the microlens 44. In the present modification example, the light-receiving areas of the respective first photoelectric conversion sections 42a and the respective second photoelectric conversion sections 42b of the first to third AF pixel pairs are different from each other. In this case, the first to third AF pixel pairs can also perform pupil division in correspondence with different angles of incidence, as in the case of the above-described embodiment.

[0170] (Modification Example 8)

[0171] The pixel selection section 213 can also select a plurality of types of AF pixel pairs. In this case, the focus detection section 215 can also calculate a plurality of defocus amounts from the plurality of types of AF pixel pairs that are selected, and calculate the movement amount of the focus lens 31b based on the average of the defocus amounts. For example, the movement amount of the focus lens 31b can also be determined based on the average of the defocus amounts calculated using the first signal Sig1 and the second signal Sig2 of the first AF pixel pair, and the defocus amounts calculated using the first signal Sig1 and the second signal Sig2 of the second AF pixel pair.

[0172] (Modification Example 9)

[0173] In the above-described embodiment, a case in which a color filter of a primary color system (RGB) is used in the imaging element 22 is described, but a color filter of a complementary color system (CMY) can also be used.

[0174] (Modification Example 10)

[0175] The imaging apparatus described in the above-described embodiment and modification examples can also be applied to a camera, a smartphone, a tablet, a camera built into a PC, a vehicle-mounted camera, a camera mounted on an unmanned aerial vehicle (drone, radio-controlled machine, or the like), and the like.

[0176] In the above, various embodiments and modification examples are described, but the present application is not limited to these. Other technical solutions that can be conceived within the scope of the technical idea of the present application are also included in the scope of the present application.

[0177] The disclosure of the following priority basis application is hereby incorporated by reference.

[0178] Japanese Patent Application No. 2018-137274 (filed on July 20, 2018)

[0179] Explanation of Reference Numerals

[0180] 1 imaging device; 2 camera body; 3 interchangeable lens; 11 AF pixel; 12 AF pixel; 13 imaging pixel; 22 imaging element; 31 imaging optical system; 32 lens control section; 42 photoelectric conversion section; 210 body control section; 211 region setting section; 212 distance calculation section; 213 pixel selection section; 214 readout section; 215 focus detection section; 216 image data generation section.

Claims

1. A camera element comprising: The first pixel pair includes a first light shielding portion, receives light transmitted through the optical system, and outputs a signal used for focus detection. a second pixel pair having a second light shielding portion having an area different from that of the first light shielding portion, receiving light having passed through different regions of the exit pupil of the optical system and outputting a signal used for focus detection; a third pixel that receives light transmitted through the optical system and outputs a signal used for image generation; and An output unit outputs a signal of any one of the first pixel pair and the second pixel pair selected based on an exit pupil distance determined based on information regarding a position of a set focus detection area and information regarding the exit pupil distance of the optical system, at a timing different from that of outputting a signal of the third pixel.

2. The imaging element according to claim 1, The output unit outputs the signal of the one pixel pair before the signal of the third pixel.

3. The imaging element according to claim 2, The output unit can switch between a first readout in which the signal of the one pixel pair is output before the signal of the third pixel, and a second readout in which the signals are output according to the order of arrangement in the row direction regardless of the exit pupil distance.

4. The imaging element according to claim 3, having a plurality of the third pixels, The output unit performs the first readout when the signals of the plurality of third pixels are output after being thinned out or when the signals of the plurality of third pixels are output after being added, and performs the second readout when the signals of the plurality of third pixels are output without being thinned out or without being added.

5. The imaging element according to claim 1, A signal line is provided for outputting a signal of the one pixel pair and a signal of the third pixel.

6. The imaging element according to claim 1, The first pixel pair includes a first pixel, the second pixel pair includes a second pixel, At least one third pixel is disposed between the first pixel and the second pixel in the column direction.

7. The imaging element according to claim 1, The first pixel pair includes a first pixel, the second pixel pair includes a second pixel, having a first pixel row including a plurality of the first pixels arranged along a first direction, a second pixel row including a plurality of the second pixels arranged along the first direction, and a third pixel row including a plurality of the third pixels arranged along the first direction, In a second direction orthogonal to the first direction, the third pixel row, the first pixel row, and the second pixel row are arranged in this order from the top. When the first pixel pair is selected, the signals of the pixels of the first pixel row are output before the signals of the pixels of the third pixel row. When the second pixel pair is selected, the signals of the pixels of the second pixel row are output before the signals of the pixels of the third pixel row.

8. The imaging element according to claim 1, The first pixel pair and the second pixel pair are respectively provided in both a first focus detection area and a second focus detection area located farther from the optical axis of the optical system than the first focus detection area. When both the first focus detection area and the second focus detection area are set as the focus detection areas, the output unit outputs a signal of the pixel pair on the one side selected based on the exit pupil distance, and the exit pupil distance is determined based on information related to the position of the second focus detection area and information related to the optical system.

9. A photographing device comprising: The imaging element according to any one of claims 1 to 8; and A focus detection unit performs focus detection based on a signal from the one pixel pair.

Images