WO2020017641A1 - Dispositif de détection de mise au point, dispositif de capture d'image et lentille interchangeable - Google Patents

Dispositif de détection de mise au point, dispositif de capture d'image et lentille interchangeable Download PDF

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Publication number
WO2020017641A1
WO2020017641A1 PCT/JP2019/028477 JP2019028477W WO2020017641A1 WO 2020017641 A1 WO2020017641 A1 WO 2020017641A1 JP 2019028477 W JP2019028477 W JP 2019028477W WO 2020017641 A1 WO2020017641 A1 WO 2020017641A1
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WIPO (PCT)
Prior art keywords
focus detection
pixel
signal
unit
correlation
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PCT/JP2019/028477
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English (en)
Japanese (ja)
Inventor
朗 木下
法義 立川
祐起 喜多
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株式会社ニコン
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Priority to JP2020531389A priority Critical patent/JP7238896B2/ja
Publication of WO2020017641A1 publication Critical patent/WO2020017641A1/fr

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
    • G02B7/28—Systems for automatic generation of focusing signals
    • G02B7/34—Systems for automatic generation of focusing signals using different areas in a pupil plane
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
    • G02B7/28—Systems for automatic generation of focusing signals
    • G02B7/36—Systems for automatic generation of focusing signals using image sharpness techniques, e.g. image processing techniques for generating autofocus signals
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B13/00—Viewfinders; Focusing aids for cameras; Means for focusing for cameras; Autofocus systems for cameras
    • G03B13/32—Means for focusing
    • G03B13/34—Power focusing
    • G03B13/36—Autofocus systems
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B17/00—Details of cameras or camera bodies; Accessories therefor
    • G03B17/02—Bodies
    • G03B17/12—Bodies with means for supporting objectives, supplementary lenses, filters, masks, or turrets
    • G03B17/14—Bodies with means for supporting objectives, supplementary lenses, filters, masks, or turrets interchangeably
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/60—Control of cameras or camera modules

Definitions

  • the present invention relates to a focus detection device, an imaging device, and an interchangeable lens.
  • a focus detection device including a focus detection pixel that receives a light beam that has passed through a partial area of an exit pupil of an imaging optical system and an imaging pixel that receives a light beam that has passed through the entire area of the exit pupil.
  • Patent Document 1 Conventionally, improvement in focus detection accuracy has been demanded.
  • a focus detection device includes a first pixel that photoelectrically converts light transmitted through a first region of an optical system and outputs a first signal, and the first region of the optical system.
  • An imaging unit having a second pixel that photoelectrically converts light transmitted through the second region and outputs a second signal; and performs focus detection of the optical system based on the first signal and the second signal.
  • a detection unit includes the focus detection device according to the first aspect, and a generation unit that generates image data based on the second signal.
  • an interchangeable lens includes a mounting portion mountable to the focus detection device according to the first aspect.
  • FIG. 1 is a diagram illustrating a configuration example of an imaging device according to a first embodiment.
  • FIG. 3 is a diagram illustrating a focus detection area on an imaging surface of the imaging device according to the first embodiment.
  • FIG. 3 is a diagram illustrating a small area in a focus detection area of the imaging device according to the first embodiment.
  • FIG. 3 is a diagram illustrating an example of an arrangement of pixels in a focus detection area of the imaging device according to the first embodiment.
  • FIG. 2 is a diagram illustrating a configuration example of a pixel in the imaging device according to the first embodiment.
  • FIG. 3 is a cross-sectional view illustrating AF pixels arranged in a central region in the imaging device according to the first embodiment.
  • FIG. 3 is a cross-sectional view showing AF pixels arranged in a region at a predetermined image height position in the imaging device according to the first embodiment.
  • FIG. 3 is a block diagram illustrating a plurality of functions performed by a focus detection unit in the imaging device according to the first embodiment, divided into blocks for each function.
  • FIG. 3 is a diagram for explaining a focus detection signal generated by the imaging device according to the first embodiment.
  • FIG. 5 is a diagram for explaining a correlation calculation process performed by the imaging device according to the first embodiment.
  • FIG. 6 is a diagram for explaining a correlation waveform addition process performed by the imaging device according to the first embodiment. 6 is a flowchart illustrating an operation of the imaging device according to the first embodiment.
  • FIG. 2 is a diagram illustrating a circuit configuration of a pixel of the image sensor according to the first embodiment.
  • FIG. 2 is a diagram illustrating a configuration of a part of the image sensor according to the first embodiment.
  • FIG. 1 is a diagram illustrating a configuration example of an electronic camera 1 (hereinafter, referred to as a camera 1) which is an example of an imaging apparatus according to the first embodiment.
  • the camera 1 includes a camera body 2 and an interchangeable lens 3. Since the camera 1 includes the camera body 2 and the interchangeable lens 3, the camera 1 may be referred to as a camera system.
  • the camera body 2 is provided with a body-side mount portion 201 to which the interchangeable lens 3 is attached.
  • the interchangeable lens 3 is provided with a lens-side mount portion 301 attached to the camera body 2.
  • the lens-side mount portion 301 and the body-side mount portion 201 are provided with a lens-side connection portion 302 and a body-side connection portion 202, respectively.
  • the lens-side connection portion 302 and the body-side connection portion 202 are provided with a plurality of terminals such as a clock signal terminal, a data signal terminal, and a power supply terminal.
  • the interchangeable lens 3 is detachably attached to the camera body 2 by a lens-side mount 301 and a body-side mount 201.
  • the terminals provided on the body-side connection portion 202 and the terminals provided on the lens-side connection portion 302 are electrically connected. This enables power supply from the camera body 2 to the interchangeable lens 3 and communication between the camera body 2 and the interchangeable lens 3.
  • the interchangeable lens 3 includes a photographing optical system (imaging optical system) 31, a lens control unit 32, and a lens memory 33.
  • the photographing optical system 31 includes a plurality of lenses including a zoom lens (magnification lens) 31 a and a focus lens (focus adjustment lens) 31 b for changing the focal length, and an aperture 31 c, and an imaging surface of the imaging element 22 of the camera body 2.
  • a subject image is formed on 22a.
  • the zoom lens 31a and the focus lens 31b are schematically illustrated in FIG. 1, a normal photographing optical system generally includes a large number of optical elements.
  • the imaging surface 22a of the imaging element 22 is, for example, a surface on which a photoelectric conversion unit described later is arranged or a surface on which a microlens is arranged.
  • the lens control unit 32 includes a processor such as a CPU, an FPGA, and an ASIC, and a memory such as a ROM and a RAM, and controls each unit of the interchangeable lens 3 based on a control program.
  • the lens control unit 32 controls the driving of the zoom lens 31a, the focus lens 31b, and the diaphragm 31c based on a signal output from the body control unit 210 of the camera body 2.
  • the lens control unit 32 moves the focus lens 31b forward and backward in the direction of the optical axis OA1 based on the signal, and performs photographing optics.
  • the focal position of the system 31 is adjusted. Further, the lens control unit 32 controls the position of the zoom lens 31a and the aperture diameter of the diaphragm 31c based on a signal output from the body control unit 210 of the camera body 2.
  • the lens memory 33 is constituted by, for example, a non-volatile storage medium.
  • Information related to the interchangeable lens 3 is stored (recorded) in the lens memory 33 as lens information.
  • the lens information includes data relating to optical characteristics (exit pupil distance and F value) of the photographing optical system 31, data relating to the infinity position and the closest position of the focus lens 31b, and the shortest focal length of the interchangeable lens (zoom lens) 3. And data on the longest focal length.
  • the exit pupil distance is a distance between the exit pupil of the imaging optical system 31 and the image plane of an image formed by the imaging optical system 31.
  • the lens information may be stored in a memory inside the lens control unit 32.
  • the lens control unit 32 transmits lens information to the body control unit 210 via the terminals of the lens-side connection unit 302 and the body-side connection unit 202. Further, the lens control unit 32 transmits to the body control unit 210 the position information (focal length information) of the controlled zoom lens 31a, the position information of the controlled focus lens 31b, the information of the F value of the controlled aperture 31c, and the like. I do.
  • the camera body 2 includes an imaging element 22, a body memory 23, a display unit 24, an operation unit 25, and a body control unit 210.
  • the image sensor 22 is a CMOS image sensor or a CCD image sensor.
  • the image sensor 22 captures a subject image formed by the imaging optical system 31.
  • a plurality of pixels having a photoelectric conversion unit are arranged in a row direction ( ⁇ X direction) and a column direction ( ⁇ Y direction).
  • the photoelectric conversion unit includes a photodiode (PD).
  • the imaging element 22 photoelectrically converts the received light with a photoelectric conversion unit to generate a signal, and outputs the generated signal to the body control unit 210.
  • the image sensor 22 includes a pixel (image pickup pixel) that outputs a signal used for image generation, an AF pixel (focus detection pixel) that outputs a signal (focus detection signal) used for focus detection, and an image generation unit. And a pixel that outputs a signal used for focus detection (imaging and AF pixel).
  • the imaging and AF pixel is a part of the imaging pixel, but since its signal is used for image generation and focus detection, it is also called an imaging and AF pixel.
  • the imaging pixel includes a pixel (hereinafter, referred to as an R pixel) having a filter having a spectral characteristic of dispersing light in the first wavelength range (red (R) light) of the incident light, A pixel having a filter (hereinafter, referred to as a G pixel) having a spectral characteristic for dispersing light in the second wavelength range (green (G) light), and light in the third wavelength range (hereinafter referred to as G pixel) of incident light There is a pixel (hereinafter, referred to as a B pixel) having a filter having spectral characteristics for dispersing blue (B) light.
  • the R pixel, the G pixel, and the B pixel are arranged according to the Bayer arrangement.
  • the AF pixels are arranged so as to be replaced with a part of the imaging pixels, and are dispersedly arranged over substantially the entire imaging surface 22a of the imaging element 22.
  • the body memory 23 is constituted by, for example, a non-volatile storage medium.
  • the body memory 23 stores image data, control programs, and the like. Writing of data to the body memory 23 and reading of data output 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 indicating a focus detection area (AF area) such as an AF frame, information on photographing such as a shutter speed and an F value, and a menu screen.
  • the operation unit 25 includes a release button, a power switch, various setting switches such as switches for switching various modes, and the like, and outputs an operation signal corresponding to each operation to the body control unit 210.
  • the body control unit 210 includes a processor such as a CPU, an FPGA, and an ASIC, and a memory such as a ROM and a RAM, and controls each unit of the camera 1 based on a control program.
  • the body control unit 210 includes an image data generation unit 211, an area setting unit 212, a pixel selection unit 213, and a focus detection unit 220.
  • the image data generation unit 211 performs various types of image processing on a signal output from an imaging pixel of the imaging element 22 to generate image data. Note that the image data generation unit 211 may generate image data also using a signal output from the AF pixel.
  • the area setting unit 212 sets (selects) at least one focus detection area 100 among the plurality of focus detection areas 100 provided on the imaging surface 22a of the imaging element 22 illustrated in FIG.
  • the plurality of AF frames displayed on the display unit 24 correspond to the plurality of focus detection areas 100 provided on the image sensor 22, respectively.
  • the area setting unit 212 selects the focus detection area 100 corresponding to the AF frame selected by the user by operating the operation unit 25 or the focus automatically selected by the camera 1 among the plurality of AF frames displayed on the display unit 24.
  • the detection area 100 is set as a focus detection area for performing focus detection.
  • the focus detection unit 220 uses a signal output from a pixel in the focus detection area 100 set by the area setting unit 212 to output a shift amount (defocus) between the image obtained by the imaging optical system 31 and the imaging surface 22a. Focus amount).
  • Each focus detection area 100 has three first, second, and third small areas 91, 92, and 93 as shown in FIG. As will be described later, each of the small areas 91 to 93 is provided with an imaging pixel, an AF pixel, and an imaging / AF pixel. At least the AF pixel and the imaging / AF pixel have different structures for each small area. ing.
  • the plurality of focus detection areas 100 are arranged in the row direction and the column direction, and are provided at different image heights.
  • a small area 92 in the focus detection area 100a at the center position of the image sensor 22 is located on the optical axis OA1 of the imaging optical system 31, and its image height H is substantially zero.
  • the image height H of the focus detection area 100 increases as the distance from the center of the imaging surface 22a (the optical axis OA1 of the imaging optical system 31) increases. In other words, the image height H of the focus detection area 100 increases as the distance from the center of the imaging surface 22a increases.
  • the focus detection area 100 farthest from the optical axis OA1 of the imaging optical system 31 (the image height H is the highest) in the row where the focus detection area 100a is located is the left end (the end in the ⁇ X direction) and the right end (+ X (Edges in the direction).
  • the focus detection areas 100 having the highest image height H in the image sensor 22 are the four focus detection areas 100 located at the corners of the imaging surface 22a.
  • the image height of the focus detection area 100 has a predetermined area, the image height differs for each AF pixel depending on the position in the focus detection area 100.
  • the value of the image height H at the center position of one focus detection area 100 is set as the value of 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 height of the focus detection areas 100b and 100c is a predetermined image height H.
  • the pixel selection unit 213 determines, for the focus detection area 100 set by the area setting unit 212, AF pixels belonging to any of the first to third small areas 91 to 93 based on the exit pupil distance of the imaging optical system 31.
  • the imaging and AF pixel is selected. For example, when the exit pupil distance of the imaging optical system 31 is equal to or greater than a first threshold, the pixel selection unit 213 selects an AF pixel belonging to the first small area 91 and an imaging / AF pixel. When the exit pupil distance is smaller than the second threshold, the pixel selection unit 213 selects an AF pixel belonging to the third small area 93 and an imaging / AF pixel. Then, when the exit pupil distance is equal to or larger than the second threshold and smaller than the first threshold, the pixel selection unit 213 selects an AF pixel belonging to the second small area 92 and an imaging / AF pixel.
  • the focus detection unit 220 performs a focus detection process required for automatic focus adjustment (AF) of the imaging optical system 31.
  • the focus detection unit 220 detects a focus position of the focus lens 31b (a movement amount of the focus lens 31b to the focus position) for focusing (imaging) an image obtained by the imaging optical system 31 on the imaging surface 22a.
  • the focus detection unit 220 calculates a defocus amount by a pupil division type phase difference detection method based on the focus detection signals output from the AF pixel selected by the pixel selection unit 213 and the imaging and AF pixel.
  • the focus detection unit 220 calculates the movement amount of the focus lens 31b to the in-focus position using the calculated defocus amount.
  • the focus detection unit 220 determines whether the defocus amount is within an allowable value. If the defocus amount is within the allowable value, the focus detection unit 220 determines that focus has been achieved. On the other hand, when the defocus amount exceeds the allowable value, the focus detection unit 220 determines that the camera is not in focus, and instructs the lens control unit 32 of the interchangeable lens 3 to move the focus lens 31b and drive the lens. Send a signal.
  • the focus control is automatically performed by the lens control unit 32 receiving the instruction output from the focus detection unit 220 moving the focus lens 31b according to the movement amount.
  • the focus detection unit 220 can also perform focus detection processing of a contrast detection method in addition to focus detection processing of a phase difference detection method.
  • the body control unit 210 sequentially calculates the contrast evaluation value of the subject image based on the signal output from the imaging pixel while moving the focus lens 31b of the imaging optical system 31 in the direction of the optical axis OA1.
  • the body control unit 210 associates the position of the focus lens 31b with the contrast evaluation value using the position information of the focus lens 31b transmitted from the interchangeable lens 3.
  • body control section 210 detects the position of focus lens 31b at which the contrast evaluation value has a peak, that is, the local maximum value, as the focus position.
  • the body control unit 210 transmits information on the position of the focus lens 31b corresponding to the detected focus position to the lens control unit 32.
  • the lens control unit 32 adjusts the focus by moving the focus lens 31b to the in-focus position.
  • FIG. 4 is a diagram showing an example of the arrangement of pixels in the first small area 91 in the focus detection area 100. 4, a first pixel group 401 in which R pixels 13 and G pixels 13 are alternately arranged in the ⁇ X direction, that is, a row direction, and G pixels 13 and B pixels 13 are alternately arranged in a row direction.
  • the second pixel groups 402 are alternately arranged in the ⁇ Y direction, that is, in the column direction.
  • the imaging pixels 13 are arranged according to a Bayer arrangement.
  • the second pixel group 402 including the first AF pixels 11 is referred to as first AF pixel lines 402Ra, 402Rb, 402Rc, and 402Rd.
  • first AF pixel lines 402Ra to 402Rd the first AF pixels 11 and the G pixels 13 are alternately arranged.
  • the first AF pixel 11 is provided between two imaging pixels 13 in the column direction and the row direction. In the example shown in FIG. 4, the first AF pixel 11 is provided between two imaging pixels 13 and is arranged adjacent to the two imaging pixels 13. Further, at least one imaging pixel 13 is arranged between two first AF pixels 11 arranged in the column direction. Note that at least one imaging pixel 13 may be arranged between two first AF pixels 11 arranged in the row direction.
  • the photoelectric conversion unit of the first AF pixel 11 receives a light beam that has passed through the first of the first and second pupil regions of the exit pupil of the imaging optical system 31.
  • the photoelectric conversion unit of the G pixel 13 receives a light beam that has passed through both the first and second pupil regions of the exit pupil of the imaging optical system 31.
  • the focus detection unit 220 calculates the phase difference between the signal of the first AF pixel 11 and the signal of the G pixel 13 for focus detection, so that the G of the first AF pixel lines 402Ra to 402Rd is calculated.
  • the pixel 13 functions as an imaging and AF pixel.
  • the first AF pixel 11 is arranged so as to replace the B pixel 13, but has a color filter 51 having a spectral characteristic of green (G).
  • the reason why the first AF pixel 11 is configured to have a green spectral characteristic is to match the spectral characteristic of the first AF pixel 11 with the spectral characteristic of the imaging and AF pixel 13 to enhance focus detection accuracy. is there.
  • a first pupil region that is a part of the exit pupil of the imaging optical system 31 may be referred to as a first region.
  • the first and second pupil areas of the exit pupil of the imaging optical system 31 may be referred to as a second area.
  • a second pupil region, which is another part of the exit pupil of the imaging optical system 31, may be referred to as a third region.
  • the first AF pixel lines 402Ra to 402Rd are provided at substantially equal intervals in the first small area 91 of the focus detection area 100. That is, the intervals between the first AF pixel lines 402Ra to 402Rd adjacent to each other are equal to each other.
  • the second pixel group 402 including the second AF pixels 12 is referred to as second AF pixel lines 402La, 402Lb, 402Lc, and 402Ld.
  • the second AF pixels 12 and the G pixels 13 are alternately arranged.
  • the second AF pixel 12 is provided between two imaging pixels 13 in the column direction and the row direction.
  • the second AF pixel 12 is provided between the two imaging pixels 13 and is arranged adjacent to the two imaging pixels 13.
  • at least one imaging pixel 13 is disposed between two second AF pixels 12 arranged in the column direction. Note that at least one imaging pixel 13 may be arranged between two second AF pixels 12 arranged in the row direction.
  • the photoelectric conversion unit of the second AF pixel 12 receives a light beam that has passed through the second pupil region of the first and second pupil regions of the exit pupil of the imaging optical system 31.
  • the focus detection unit 220 calculates the phase difference between the signal of the second AF pixel 12 and the signal of the G pixel 13 for focus detection, so that the second AF pixel lines 402La to 402Ld G pixel 13 also functions as an imaging and AF pixel.
  • the second AF pixel 12 is also disposed in place of the B pixel 13, but has a color filter 51 having green (G) spectral characteristics.
  • the second AF pixel lines 402La to 402Ld are also provided at substantially equal intervals in the first small area 91 of the focus detection area 100, and are located at intermediate positions between the adjacent first AF pixel lines 402Ra to 402Rd. I do.
  • the first and second AF pixel lines are alternately arranged at substantially equal intervals in the column direction.
  • first and second AF pixel lines 402Ra to 402Rd and 402La to 402Ld are provided in the first small area 91, and the number of the first and second AF pixel lines is equal to the first small area. It can be increased or decreased according to the size of 91, and the like.
  • the first AF pixels 11 are arranged in the same column because the B pixels of the second pixel group 402 are replaced with each other.
  • the second AF pixels 12 are arranged so as to replace the B pixels of the second pixel group 402. They are located in the same column.
  • the pixel arrangement in the first small area 91 in the focus detection area 100 is as described above, and the pixel arrangement in the remaining second and third small areas 92 and 93 in the focus detection area 100 is the first. Is the same as the small area 91.
  • the difference between the first, second, and third small areas 91, 92, and 93 is the pixel structure of the first AF pixel 11 and the second AF pixel 12, which will be described later.
  • FIG. 5 is a diagram for explaining a configuration example of AF pixels and imaging pixels provided in the imaging device 22 according to the first embodiment.
  • FIG. 5A shows an example of a cross section of the first AF pixel 11
  • FIG. 5B shows an example of a cross section of the second AF pixel 12.
  • FIG. 5C shows an example of a cross section of the imaging pixel 13 (R pixel, G pixel, B pixel).
  • both the first and second AF pixels 11 and 12 and the imaging pixel 13 photoelectrically convert the microlens 44, the color filter 51, and the light transmitted (passed) through the microlens 44 and the color filter 51.
  • a photoelectric conversion unit 42 PD42.
  • the first light beam 61 is a light beam that has passed through a first pupil region that substantially divides the exit pupil of the imaging optical system 31 into two equal parts.
  • the second light flux 62 is a light flux that has passed through a second pupil region that substantially divides the exit pupil of the imaging optical system 31 into two equal parts.
  • the first AF pixel 11 is provided with a light shielding unit 43L that shields the second light flux 62 of the first and second light fluxes 61 and 62.
  • the light blocking unit 43L is located between the color filter 51 and the photoelectric conversion unit 42 and is provided on the photoelectric conversion unit 42.
  • the light shielding unit 43L is arranged to shield the left half ( ⁇ X direction side) of the photoelectric conversion unit 42.
  • the right end (the end in the + X direction) of the light shielding portion 43L substantially coincides with the center line that divides the photoelectric conversion portion 42 into two right and left parts.
  • the area 46 of the first AF pixel 11 is an area corresponding to a substantially right half (+ X direction side) area of the photoelectric conversion unit 42, and the first light beam 61 that has passed through the microlens 44 and the color filter 51 is subjected to photoelectric conversion. It functions as an opening that allows the light to enter the conversion unit 42. Focusing on this right opening, the first AF pixel may be referred to as a right opening AF pixel 11.
  • the photoelectric conversion unit 42 of the first AF pixel 11 receives the first light flux 61.
  • the photoelectric conversion unit 42 of the first AF pixel 11 photoelectrically converts the first light flux 61 to generate electric charge, and the first AF pixel 11 performs first focus detection based on the electric charge generated by the photoelectric conversion unit 42. Output a signal.
  • the area of the light shielding portion 43L depends on the position (image height) of the first AF pixel 11 except for the first AF pixel 11 around the optical axis OA1 (the center of the imaging surface 22a) of the photographing optical system 31. different. If the position of the first AF pixel 11 is different, that is, if the image height is different, the incident angle of the light incident on the first AF pixel 11 is different. The incident angle increases as the image height increases, and decreases as the image height decreases. If the image height is 0, the incident angle is 0 °. In order to shield the second light flux 62 from the light incident at different incident angles depending on the image height, the area of the light shielding portion 43L differs depending on the image height.
  • the second AF pixel 12 is provided with a light shielding unit 43R that shields the first light flux 61 of the first and second light fluxes 61 and 62.
  • the light shielding unit 43R is located between the color filter 51 and the photoelectric conversion unit 42 and is provided on the photoelectric conversion unit 42.
  • the light shielding unit 43 ⁇ / b> R is arranged to shield the right half (+ X direction side) of the photoelectric conversion unit 42.
  • the left end (the end in the ⁇ X direction) of the light-shielding portion 43R substantially coincides with the center line that divides the photoelectric conversion portion 42 into two right and left parts.
  • the region 46 of the second AF pixel 12 is a region corresponding to a substantially left half region of the photoelectric conversion unit 42, and the second light flux 62 that has passed through the microlens 44 and the color filter 51 is Acts as an aperture that allows the light to enter. Paying attention to this left opening, the second AF pixel may be referred to as a left opening AF pixel 12.
  • the photoelectric conversion unit 42 of the second AF pixel 12 receives the second light flux 62.
  • the photoelectric conversion unit 42 of the second AF pixel 12 photoelectrically converts the second light flux 62 to generate electric charge, and the second AF pixel 12 performs second focus detection based on the electric charge generated by the photoelectric conversion unit 42. Output a signal.
  • the area of the light-shielding portion 43R is the second area except for the second AF pixel 12 around the optical axis OA1 (the center of the imaging surface 22a) of the imaging optical system 31. It depends on the position (image height) of the AF pixel 12. In order to shield the first light flux 61 among the light incident at different incident angles depending on the image height, the area of the light shielding portion 43R differs depending on the image height.
  • the photoelectric conversion unit 42 of the imaging pixel 13 receives the first and second light beams 61 and 62 that have passed through the first and second pupil regions of the exit pupil of the imaging optical system 31, respectively. .
  • the photoelectric conversion unit 42 of the imaging pixel 13 photoelectrically converts the first and second light fluxes 61 and 62 to generate electric charges, and the imaging pixel 13 outputs a signal based on the electric charge generated by the photoelectric conversion unit 42.
  • the G pixels 13 on the first AF pixel lines 402Ra to 402Rd and the G pixels 13 on the second AF pixel lines 402La to 402Ld function as imaging and AF pixels.
  • the G pixels 13 of the first and second AF pixel lines output a third focus detection signal based on the charges generated by the photoelectric conversion unit 42.
  • FIG. 6 is a cross-sectional view of AF pixels arranged in the first to third small areas 91 to 93 in the focus detection area 100a of FIG.
  • FIG. 6A shows the first and second AF pixels 11 a and 12 a arranged in the first small area 91.
  • FIG. 6B shows the first and second AF pixels 11 b and 12 b arranged in the second small area 92.
  • FIG. 6C shows the first and second AF pixels 11c and 12c arranged in the third small area 93.
  • the line passing through the center of the photoelectric conversion unit 42 substantially coincides with the optical axis of the microlens 44. I have.
  • the right end (the end in the + X direction) of the light shielding portion 43L substantially coincides with the optical axis OA2 of the micro lens 44.
  • the light shielding unit 43L of the first AF pixel 11a shields the left half ( ⁇ X direction side) of the photoelectric conversion unit 42 from light.
  • the second light flux 62 transmitted through the microlens 44 is shielded by the light shielding unit 43L before being incident on the photoelectric conversion unit 42. Accordingly, the photoelectric conversion unit 42 of the first AF pixel 11a receives the first light flux 61.
  • the left end (the end in the ⁇ X direction) of the light shielding portion 43R substantially coincides with the optical axis OA2 of the micro lens 44.
  • the first light flux 61 transmitted through the microlens 44 is shielded by the light shielding unit 43R before entering the photoelectric conversion unit 42.
  • the photoelectric conversion unit 42 of the second AF pixel 12a receives the second light flux 62.
  • each of the photoelectric conversion units 42 of the first AF pixels 11b and 11c receives the first light flux 61.
  • the left end (the end in the ⁇ X direction) of the light shielding portion 43R substantially coincides with the optical axis OA2 of the micro lens 44. Therefore, similarly to the first AF pixel 12a, each of the photoelectric conversion units 42 of the second AF pixels 12b and 12c receives the second light flux 62.
  • FIG. 7 is a cross-sectional view of AF pixels arranged in the first to third small areas 91 to 93 of the focus detection area 100c separated in the + X direction from the focus detection area 100a in FIG.
  • FIG. 7A shows the first and second AF pixels 11 a and 12 a arranged in the first small area 91.
  • FIG. 7B shows the first and second AF pixels 11 b and 12 b arranged in the second small area 92.
  • FIG. 7C shows the first and second AF pixels 11c and 12c arranged in the third small area 93.
  • the line passing through the center of the photoelectric conversion unit 42 is shifted in the + X direction with respect to the optical axis OA2 of the microlens 44.
  • the first and second AF pixels arranged apart from the focus detection area 100a in the + X direction have a line passing through the center of the photoelectric conversion unit 42 at + X with respect to the optical axis OA2 of the microlens 44. It is shifted in the direction.
  • first and second AF pixels disposed apart from the focus detection area 100a in the ⁇ X direction have a line passing through the center of the photoelectric conversion unit 42 in the ⁇ X direction with respect to the optical axis OA2 of the microlens 44. It is out of alignment.
  • the areas of the light shielding portions 43L included in the first AF pixels 11a to 11c are different.
  • the area of the light shielding part 43L of the first AF pixel 11a is smaller than the area of the light shielding part 43L of the first AF pixel 11b.
  • the area of the light shielding part 43L of the first AF pixel 11b is smaller than the area of the light shielding part 43L of the first AF pixel 11c.
  • Each of the second AF pixels 12a to 12c has a different area of the light shielding portion 43R.
  • the area of the light shield 43R of the second AF pixel 12a is larger than the area of the light shield 43R of the second AF pixel 12b.
  • the area of the light shield 43R of the second AF pixel 12b is larger than the area of the light shield 43R of the second AF pixel 12c.
  • the left end (the end in the ⁇ X direction) of the light shielding portion 43R is located on the + X direction side by a shift amount d1 from the optical axis OA2 of the micro lens 44.
  • the AF pixels arranged in the second and third small areas 92 and 93 are different from the AF pixels arranged in the first small area 91 in the amount of shift.
  • the shift amount d2 between the first and second AF pixels 11b and 12b is larger than the shift amount d1 between the first AF pixels 11a and 12a.
  • the shift amount d3 between the first and second AF pixels 11c and 12c is larger than the shift amount d2 between the first and second AF pixels 11b and 12b. That is, d1 ⁇ d2 ⁇ d3.
  • the amount of deviation between the line passing through the center of the photoelectric conversion unit 42 and the optical axis OA2 of the microlens 44 differs depending on the image height.
  • the shift amount increases as the image height increases, and the shift amount decreases as the image height decreases.
  • the light transmitted through the photographing optical system 31 obliquely enters the microlens 44. That is, light enters the optical axis OA2 of the microlens 44 at an incident angle larger than 0 °. Therefore, it can be said that the larger the angle of incidence of light on the microlens 44, the larger the amount of displacement.
  • Light incident on the optical axis OA2 of the microlens 44 at an incident angle larger than 0 ° is condensed while being shifted from the optical axis OA2 of the microlens 44 in the + X direction or the ⁇ X direction.
  • the line passing through the center of the photoelectric conversion unit 42 and the optical axis OA2 of the microlens 44 are shifted, the light incident on the microlens 44 is focused on the line passing through the center of the photoelectric conversion unit 42. That is, the light transmitted through the photographing optical system 31 is collected on a line passing through the center of the photoelectric conversion unit 42.
  • the amount of light that passes through the imaging optical system 31 and enters the photoelectric conversion unit 42 can be increased.
  • the area of the light shielding portion 43 differs depending on the AF pixels arranged in the first to third small regions 91 to 93.
  • Each of the first and second AF pixels arranged in the first to third small regions 91 to 93 has a light shielding portion 43 having a different area.
  • the focus detection unit 220 can accurately detect the defocus amount even at different exit pupil distances.
  • the amount of shift between the first AF pixels 11a to 11c and the second AF pixels 12a to 12c increases as the image height increases in the + X direction from the focus detection area 100a. For example, comparing the shift amounts of the first and second AF pixels in three small regions 91, 92, and 93 with image heights of Ha, Hb, and Hc (Ha ⁇ Hb ⁇ Hc), the following is obtained.
  • the shift amount between the first and second AF pixels in the first small area 91 having the image height Hb is larger than the shift amount between the first and second AF pixels in the first small area 91 having the image height Ha.
  • the shift amount of the first and second AF pixels in the first small area 91 having the image height Hc is smaller than the shift amount.
  • the shift amounts of the first and second AF pixels in the second and third small regions 92 and 93 having the image height Hb are respectively equal to the shift amounts of the second and third small regions 92 and 93 having the image height Ha. It is larger than the shift amount between the first and second AF pixels, and smaller than the shift amount between the first and second AF pixels in the second and third small regions 92 and 93 having the image height Hc.
  • the shift amount d1 is opposite to the shift direction illustrated in FIG. A shift amount similar to that of d3 is provided.
  • the shift amount of the focus detection area away from the center focus detection area 100a in the ⁇ X direction also increases as the image height increases.
  • the first and second AF pixels disposed in the first, second, and third small areas 91, 92, and 93 have different amounts of displacement.
  • the areas where the photoelectric conversion units 42 of the first AF pixels 11a to 11c receive light are different from each other, and the photoelectric conversion units of the second AF pixels 12a to 12c are different from each other. Areas 42 receive light differently.
  • the first and second AF pixels arranged in the first, second, and third small regions 91, 92, and 93 respectively have the light receiving area of the photoelectric conversion unit 42. Due to the difference, pupil division can be performed corresponding to mutually different incident angles. Thereby, the focus detection unit 220 can accurately detect the defocus amount.
  • the focus detection unit 220 includes a pseudo focus detection signal generation unit 220a, a pixel addition unit 220b, a correlation calculation unit 220c, a reliability determination unit 220d, a correlation waveform processing unit 220e, and an image shift amount calculation unit. 220f, an image shift amount adding unit 220g, a defocus amount calculating unit 220h, a lens moving amount calculating unit 220i, and a focus detection area enlarging unit 220j.
  • the plurality of blocks may be configured by one block, or any one of the blocks may be divided into a plurality of blocks. Further, the pseudo focus detection signal generation unit 220a, the pixel addition unit 220b, and the like may not be part of the focus detection unit 220, and may have an independent configuration.
  • the pixel selection unit 213 selects one of the first to third small areas 91 to 93 based on the exit pupil distance of the imaging optical system 31. And the first and second AF lines 402R and 402L belonging to.
  • the focus detection unit 220 is output from the first and second AF pixels 11 and 12 and the imaging and AF pixel 13 (G pixel 13) of the first and second AF pixel lines selected by the pixel selection unit 213. Focus detection processing is performed using the first to third focus detection signals. As described later, the focus detection unit 220 also performs focus detection based on a focus detection signal output from a pixel in the focus detection area enlarged by the focus detection area enlargement unit 220j.
  • the pseudo focus detection signal generation unit 220a uses the first and third focus detection signals output from the first AF pixel 11 and the imaging / AF pixel 13 of the first AF pixel lines 402Ra to 402Rd to generate a pseudo focus detection signal.
  • a second focus detection signal (second pseudo focus detection signal) is generated.
  • the pseudo focus detection signal generation unit 220a uses the second and third focus detection signals output from the second AF pixel 12 and the imaging / AF pixel 13 of the second AF pixel lines 402La to 402Ld, A pseudo first focus detection signal (first pseudo focus detection signal) is generated.
  • the pseudo focus detection signal generation unit 220a outputs the third AF / AF pixels 13 adjacent to the first AF pixel 11 in the row direction.
  • the second pseudo focus detection signal is calculated by subtracting the first focus detection signal of the first AF pixel 11 from the average value of the focus detection signals.
  • the average value of the third focus detection signals of the two imaging and AF pixels 13 is calculated as the third focus detection signal of the imaging and AF pixel 13 virtually arranged at the position of the first AF pixel 11 (see FIG. 5). (Corresponding to the first and second light fluxes 61 and 62).
  • the second pseudo focus detection signal (the second focus detection signal in FIG.
  • the pseudo focus detection signal generation unit 220a determines the second focus detection signal from the third focus detection signal of the imaging / AF pixel 13 on the left (-X direction side) or right (+ X direction side) of the first AF pixel 11.
  • a signal obtained by subtracting the first focus detection signal of one AF pixel 11 may be calculated as a second pseudo focus detection signal.
  • the pseudo focus detection signal generation unit 220a uses signals output from two imaging pixels 13 adjacent to the first AF pixel 11 in the column direction or eight imaging pixels 13 around the first AF pixel 11. , A second pseudo focus detection signal may be calculated.
  • the first focus detection signal is output from the first AF pixel 11
  • the second pseudo focus detection signal is output from the second AF pixel 11 virtually located at the position of the first AF pixel 11.
  • a pair of the first focus detection signal and the second pseudo focus detection signal is a virtual AF pixel including two photoelectric conversion units for photoelectrically converting the light transmitted through the microlens shown in FIG. This is equivalent to a pair of focus detection signals output from 110.
  • the virtual AF pixel 110 shown in FIG. 9A is a micro lens on which the first and second light beams 61 and 62 that have passed through the first and second pupil regions of the exit pupil of the photographing optical system respectively enter. 44, and first and second photoelectric conversion units 42a and 42b that receive the first and second light beams 61 and 62, respectively.
  • the virtual AF pixel 110 outputs a first focus detection signal (corresponding to the first light flux 61 in FIG. 5) and a second focus detection signal (corresponding to the second light flux 62 in FIG. 5). I do.
  • the first focus detection signal and the second pseudo focus detection signal of the present embodiment can be considered to be equivalent to the signal output by the virtual AF pixel 110 shown in FIG. Therefore, the following description will be made on the assumption that the first focus detection signal and the second pseudo focus detection signal are output from the virtual AF pixel 110 in FIG. Note that a pair of the first focus detection signal and the second pseudo focus detection signal is used to calculate an image shift amount between an image formed by the first light beam 61 and an image formed by the second light beam 62.
  • the pseudo focus detection signal generation unit 220a performs the third focus detection of two imaging and AF pixels 13 adjacent to the second AF pixel 12 in the row direction.
  • the first pseudo focus detection signal is calculated by subtracting the second focus detection signal of the second AF pixel 12 from the average value of the signal.
  • the average value of the third focus detection signals of the two imaging and AF pixels 13 is the third focus detection signal of the imaging and AF pixel 13 virtually arranged at the position of the second AF pixel 12 (see FIG. 5). (Corresponding to the first and second light fluxes 61 and 62).
  • a first pseudo focus detection signal (the first focus detection signal in FIG.
  • the pseudo focus detection signal generation unit 220a calculates the first focus detection signal from the third focus detection signal of the imaging / AF pixel 13 on the left (-X direction side) or right (+ X direction side) of the second AF pixel 12.
  • a signal obtained by subtracting the second focus detection signal of the two AF pixels 12 may be calculated as the first pseudo focus detection signal.
  • the pseudo focus detection signal generation unit 220a uses signals output from two imaging pixels 13 adjacent to the second AF pixel 12 in the column direction or eight imaging pixels 13 around the second AF pixel 12. , The first pseudo focus detection signal may be calculated.
  • the second focus detection signal is output from the second AF pixel 12
  • the first pseudo focus detection signal is output from the first AF pixel 12 virtually located at the position of the second AF pixel 12.
  • a pair of the second focus detection signal and the first pseudo focus detection signal is a virtual AF pixel including two photoelectric conversion units that photoelectrically converts light transmitted through the microlens shown in FIG. 9B. This is equivalent to a pair of focus detection signals output from the signal 120.
  • the virtual AF pixel 120 shown in FIG. 9B is a micro lens on which the first and second light beams 61 and 62 that have passed through the first and second pupil regions of the exit pupil of the photographing optical system are incident. 44, and first and second photoelectric conversion units 42a and 42b that receive the first and second light beams 61 and 62, respectively.
  • the virtual AF pixel 120 outputs a first focus detection signal (corresponding to the first light flux 61 in FIG. 5) and a second focus detection signal (corresponding to the second light flux 62 in FIG. 5). I do.
  • the first pseudo focus detection signal and the second focus detection signal of the present embodiment can be considered to be equivalent to the signal output from the virtual AF pixel 120 shown in FIG. 9B. Therefore, hereinafter, the description will be given assuming that the first pseudo focus detection signal and the second focus detection signal are output from the virtual AF pixel 120 in FIG. 9B as necessary. Note that a pair of the first pseudo focus detection signal and the second focus detection signal is used to calculate an image shift amount between an image formed by the first light beam 61 and an image formed by the second light beam 62.
  • the pseudo focus detection signal generation unit 220a generates the first pseudo focus detection signal and the second pseudo focus detection signal.
  • a pair of a first focus detection signal and a third focus detection signal, and a pair of a second focus detection signal and a third focus detection signal are used as a pair of focus detection signals to be correlated.
  • the focus detection unit 220 calculates the defocus amount using at least one pair of focus detection signals among the plurality of pairs of focus detection signals. For example, the focus detection unit 220 calculates a phase difference (image shift amount) between a pair of focus detection signals based on a pair of the first focus detection signal and the third focus detection signal, and converts the phase shift amount into a predetermined conversion coefficient. To calculate the defocus amount. Similarly, the focus detection unit 220 may calculate the defocus amount based on a phase difference between a pair of focus detection signals based on a pair of the second focus detection signal and the third focus detection signal. Good.
  • the focus detection unit 220 may detect a phase difference between a pair of focus detection signals based on the pair of the first focus detection signal and the third focus detection signal, and a pair of the second focus detection signal and the third focus detection signal.
  • the defocus amount may be calculated based on the phase difference between a pair of focus detection signals based on the above.
  • the focus detection unit 220 is configured to generate a difference between the first focus detection signal and the third focus detection signal (a second pseudo focus detection signal) and a position of a pair of focus detection signals based on a pair of the third focus detection signal.
  • the defocus amount can be calculated based on the phase difference.
  • the focus detection unit 220 similarly, generates a pair of signals based on a pair of a signal (first pseudo focus detection signal) of a difference between the second focus detection signal and the third focus detection signal and a third focus detection signal.
  • the defocus amount may be calculated based on the phase difference between the focus detection signals.
  • the focus detection unit 220 includes a phase difference between a pair of focus detection signals based on a pair of the first pseudo focus detection signal and the third focus detection signal, and a second pseudo focus detection signal and a third focus detection signal.
  • the defocus amount may be calculated based on a phase difference between a pair of focus detection signals based on the pair.
  • the focus detection unit 220 can also calculate the defocus amount based on a phase difference between a pair of focus detection signals based on a pair of the first focus detection signal and the second pseudo focus detection signal.
  • the focus detection unit 220 calculates a defocus amount based on a phase difference between a pair of focus detection signals based on a pair of the first pseudo focus detection signal and the second focus detection signal. Is also good.
  • the correlation (degree of coincidence) between the above-mentioned pair of focus detection signals changes depending on, for example, the degree of blurring of the subject image.
  • the image formed by the first light beam 61 in FIG. 5 or the image formed by the second light beam 62 in FIG. 5 and the image formed by the first and second light beams 61 and 62 in FIG. Is different.
  • the difference between the waveforms of the signals based on the plurality of first focus detection signals (or the second focus detection signals) and the waveforms of the signals based on the plurality of third focus detection signals increases, and the first The correlation between the focus detection signal (or the second focus detection signal) and the third focus detection signal decreases.
  • the focus detection unit 220 selects a pair of the first focus detection signal (or the second focus detection signal) and the third focus detection signal. Then, the defocus amount is calculated.
  • the focus detection unit 220 outputs the pair of the first focus detection signal and the second pseudo focus detection signal, and the pair of the first pseudo focus detection signal and the second focus detection signal.
  • a defocus amount is calculated by selecting either a pair or a pair of added focus detection signals described later. As described above, the focus detection unit 220 switches the pair of focus detection signals used for focus detection based on the state of the subject image. Therefore, the focus detection accuracy can be improved.
  • the pixel addition unit 220b adds the first focus detection signals of the four first AF pixels 11 located in the same column of the first AF pixel lines 402Ra, 402Rb, 402Rc, and 402Rd, and is located in the same column.
  • the third focus detection signals of the four imaging and AF pixels 13 are added. That is, the pixel addition unit 220b adds the first focus detection signals of the first AF pixels 11 of the four first AF pixel lines 402Ra to 402Rd arranged in the column direction in FIG. Further, the pixel addition unit 220b adds the third focus detection signals of the four imaging and AF pixels 13 of the first AF pixel lines 402Ra to 402Rd arranged in the column direction.
  • the pixel addition unit 220b outputs the signal obtained by adding the plurality of first focus detection signals (addition first focus detection signal) and the signal obtained by adding the plurality of third focus detection signals (addition third focus detection signal). Signal).
  • adding the first focus detection signals of the four first AF pixels 11 belonging to the four first AF pixel lines Ra, 402Rb, 402Rc, and 402Rd will be described below. It is said that the first focus detection signal is added for every minute.
  • the pixel addition unit 220b adds the second focus detection signals of the four second AF pixels 12 located on the same column of the second AF pixel lines 402La, 402Lb, 402Lc, and 402Ld, and adds the same column. Are added to the third focus detection signals of the four imaging and AF pixels 13 located at the position. In this way, the pixel adding unit 220b adds the signal obtained by adding the plurality of second focus detection signals (added second focus detection signal) and the signal obtained by adding the plurality of third focus detection signals (added third focus detection signal). Signal). As described above, adding the second focus detection signals of the four second AF pixels 12 belonging to the four second AF pixel lines 402La, 402Lb, 402Lc, and 402Ld will be described below. That is, the second focus detection signal is added.
  • the pixel addition unit 220b adds the four first pseudo focus detection signals at the positions of the second AF pixels 12 located on the same column of the second AF pixel lines 402La to 402Ld. In this way, the pixel addition unit 220b generates a signal obtained by adding the plurality of first pseudo focus detection signals (addition first pseudo focus detection signal). Further, the pixel addition unit 220b generates a signal (mixed first focus detection signal) obtained by adding the addition first focus detection signal and the addition first pseudo focus detection signal.
  • the pixel addition unit 220b adds the four second pseudo focus detection signals at the positions of the first AF pixels 11 located in the same column of the first AF pixel lines 402Ra to 402Rd. In this way, the pixel addition unit 220b generates a signal obtained by adding the plurality of second pseudo focus detection signals (addition second pseudo focus detection signal). Further, the pixel addition unit 220b generates a signal (mixed second focus detection signal) obtained by adding the addition second focus detection signal and the addition second pseudo focus detection signal.
  • FIGS. 9A and 9B show the addition of the first focus detection signal and the first pseudo focus detection signal and the addition of the second focus detection signal and the second pseudo focus detection signal.
  • the virtual AF pixel 110 corresponds to each of the first AF pixel lines 402Ra to 402Rd
  • the virtual AF pixel 120 corresponds to the second AF pixel lines 402La to 402Ld. Minutes exist.
  • four first focus detection signals and virtual AF output from the virtual AF pixels 110 The four first pseudo focus detection signals output from the pixels 120 are added.
  • four second pseudo focus detection signals output from the virtual AF pixels 110 The four second focus detection signals output from the virtual AF pixels 120 are added.
  • the correlation calculation unit 220c performs a correlation calculation process on a pair of focus detection signals, that is, a pair of signal trains.
  • the pair of focus detection signals (a pair of signal trains) is, for example, a plurality of first focus detection signals output from the plurality of first AF pixels 11 belonging to the first AF pixel line 402Ra.
  • a focus detection signal generated from a plurality of first focus detection signals is simply referred to as a first focus detection signal
  • a focus detection signal generated from a plurality of third focus detection signals is simply referred to as a third focus detection signal. Name.
  • a pair of focus detection signals are respectively output from the plurality of first AF pixels 11 belonging to the first AF pixel line 402 (402Rb, 402Rc or 402Rd) other than the first AF pixel line 402Ra.
  • the focus detection signals (signal trains) generated from the plurality of first focus detection signals are output from the plurality of imaging / AF pixels 13 belonging to the first AF pixel line 402 other than the first AF pixel line 402Ra.
  • a focus detection signal (signal train) generated from the plurality of third focus detection signals.
  • the pair of focus detection signals include a plurality of second focus detection signals output from a plurality of second AF pixels 12 belonging to the second AF pixel line 402 (402La, 402Lb, 402Lc, or 402Ld).
  • Signal sequence the first, second, and third added focus detection signals, the added first and second pseudo focus detection signals, and the focus detection signals generated from each of the combined first and second focus detection signals
  • the signal train is used for a pair of focus detection signals (a pair of signal trains).
  • the correlation calculation unit 220c performs a correlation calculation while changing the relative shift amount of the pair of signal trains, and generates data (correlation waveform) indicating the correspondence between the correlation amount (correlation value) and the shift amount.
  • the correlation operation unit 220c performs, for example, a correlation operation of the following equation (1) on the pair of signal sequences, and calculates a correlation amount C (k).
  • C (k) ⁇
  • k is a relative shift amount in units of a pixel pitch (pixel interval) of AF pixels.
  • the correlation calculation unit 220c calculates a minimum value (minimum value) C (x) for a continuous correlation amount and a shift amount x that gives the minimum value C (x) using a known three-point interpolation technique. .
  • the correlation calculator 220c calculates the image shift amount ⁇ using the shift amount x.
  • the correlation calculation unit 220c performs a correlation calculation between the first focus detection signal and the third focus detection signal for each of the first AF pixel lines 402Ra to 402Rd. That is, the correlation operation unit 220c performs the correlation operation on each of the first AF pixel lines 402Ra to 402Rd to calculate four first correlation waveforms C1.
  • the first correlation waveform C1 is data indicating a relationship between a correlation amount calculated by performing a correlation operation on the first focus detection signal and the third focus detection signal of the first AF pixel line and a shift amount.
  • the correlation calculation unit 220c calculates the correlation between the second focus detection signal and the third focus detection signal for each of the second AF pixel lines 402La to 402Ld, and calculates four second correlation waveforms C2. .
  • the second correlation waveform C2 is data indicating a relationship between a correlation amount calculated by performing a correlation operation between the second focus detection signal and the third focus detection signal of the second AF pixel line and the shift amount.
  • the correlation calculator 220c calculates a correlation between the first focus detection signal and the second pseudo focus detection signal for each of the first AF pixel lines 402Ra to 402Rd, and calculates four third correlation waveforms C3. I do.
  • the third correlation waveform C3 is data indicating a relationship between a correlation amount calculated by performing a correlation operation on the first focus detection signal and the second pseudo focus detection signal of the first AF pixel line and a shift amount. .
  • the correlation calculator 220c calculates a correlation between the first pseudo focus detection signal and the second focus detection signal for each of the second AF pixel lines 402La to 402Ld, and calculates four fourth correlation waveforms C4. I do.
  • the fourth correlation waveform C4 is data indicating the relationship between the correlation amount calculated by performing a correlation operation between the second focus detection signal and the first pseudo focus detection signal of the second AF pixel line and the shift amount. .
  • the correlation calculation unit 220c performs a correlation calculation between the added first focus detection signal to which the four first AF pixel lines 402Ra to 402Rd are added by the pixel addition unit 220b and the added third focus detection signal, A first correlation waveform C10 is calculated. Further, the correlation calculating section 220c calculates a correlation between the added second focus detection signal obtained by adding the four AF pixel lines 402La to 402Ld by the pixel adding section 220b and the added third focus detection signal. Thus, a second correlation waveform C20 is calculated.
  • the correlation operation unit 220c is configured to add the combined first focus detection signal and the added first pseudo focus detection signal, and to add the mixed first focus detection signal, the added second focus detection signal, and the added second pseudo focus detection.
  • a fifth correlation waveform C5 is calculated by performing a correlation operation on the mixed second focus detection signal to which the signal has been added.
  • the reliability determination unit 220d determines the reliability of the correlation operation, that is, the reliability (reliability) of the generated correlation waveform.
  • the reliability reliability
  • the minimum value C (x) of the correlation amount becomes small as shown in FIG. .
  • the degree of correlation (coincidence) between a pair of signal trains is high, the waveform of the first or second focus detection signal and the waveform of the third focus detection signal greatly differ due to, for example, blurring or vignetting. In such a case, as shown in FIG. 10B, the minimum value C (x) of the correlation amount becomes large.
  • the reliability determination unit 220d calculates the minimum value of the correlation amount from the correlation waveform, and determines the reliability of the correlation waveform based on the minimum value of the correlation amount. For example, the reliability determining unit 220d determines that the reliability of the correlation waveform is low when the minimum value of the correlation amount is larger than the predetermined threshold Th, and determines that the minimum value of the correlation amount is smaller than the predetermined threshold Th. Determines that the reliability of the correlation waveform is high.
  • the correlation waveform processing unit 220e performs a process of adding a plurality of correlation waveforms based on the determination result by the reliability determination unit 220d, or creates an inverted waveform by inverting one of the two correlation waveforms, and The processing of adding the correlation waveform is performed.
  • the correlation waveform processing unit 220e adds four first correlation waveforms C1 or adds a second correlation waveform C2.
  • the first correlation waveform C1 plotted by a black point and the second correlation waveform C2 plotted by an X have a phase shift of a predetermined amount D. Therefore, the correlation waveform processing unit 220e inverts the first correlation waveform C1 left and right about the central axis (the center of the predetermined amount D), for example.
  • the inverted first correlation waveform C1 and second correlation waveform C2 are added.
  • the correlation waveform processing unit 220e inverts one of the first correlation waveform C1 and the second correlation waveform C2, and adds the inverted correlation waveform to the other correlation waveform (first correlation waveform). Is generated. Further, the correlation waveform processing unit 220e inverts one of the first correlation waveform C10 and the second correlation waveform C20, and adds the inverted correlation waveform to the other correlation waveform (second added correlation waveform). Waveform). As will be described later, an image shift amount is calculated based on the added correlation waveform, and is converted into a defocus amount.
  • the reason for inverting one of the first and second correlation waveforms C1 and C2, adding it to the other correlation waveform, and calculating the defocus amount based on the added correlation waveform is as follows. That is, this method has higher focus detection accuracy than calculating the defocus amount based on each of the first and second correlation waveforms C1 and C2 and calculating the average value of the defocus amounts. is there. Note that the process of inverting one of the first and second correlation waveforms C1 and C2 and adding the other to the other is performed, as shown in FIG. 11, by combining the first correlation waveform C1 and the second correlation waveform C2. Need to be almost symmetrical.
  • Such a correlation waveform having left-right symmetry is obtained from a focus detection signal of a focus detection area having a relatively small image height (near the center of the imaging surface 22a). Note that the same applies to the reason that one of the first and second correlation waveforms C10 and C20 is inverted, added to the other correlation waveform, and the defocus amount is calculated based on the added correlation waveform.
  • the image shift amount calculation unit 220f calculates the phase difference between the pair of focus detection signals, that is, the image shift amount, based on the correlation waveform generated using the pair of focus detection signals.
  • the image shift amount calculation unit 220f calculates the image shift amount based on the shift amount that minimizes the correlation amount.
  • the image shift amount calculation unit 220f uses the first correlation waveform C1 to set the image shift amount ⁇ 1 between the image formed by the first light flux 61 and the images formed by the first light flux 61 and the second light flux 62, ie, the first An image shift amount that is half the image shift amount between the image formed by the light beam 61 and the image formed by the second light beam 62 is calculated.
  • the image shift amount calculating unit 220f uses the second correlation waveform C2 to set the image shift amount ⁇ 2 between the image formed by the second light flux 62 and the images formed by the first light flux 61 and the second light flux 62, ie, Then, an image shift amount that is the remaining half of the image shift amount between the image formed by the first light beam 61 and the image formed by the second light beam 62 is calculated.
  • the image shift amount calculating unit 220f calculates the image shift amount ( ⁇ 1 + ⁇ 2) between the image formed by the first light flux 61 and the image formed by the second light flux 62 by using the third correlation waveform C3.
  • the image shift amount calculation unit 220f calculates the image shift amount ( ⁇ 1 + ⁇ 2) between the image formed by the first light beam 61 and the image formed by the second light beam 62 using the fourth correlation waveform C4.
  • the image shift amount calculation unit 220f uses the first correlation waveform C10 to set the image shift amount ⁇ 1 between the image formed by the first light flux 61 and the images formed by the first and second light fluxes 61 and 62, that is, the first shift amount.
  • An image shift amount that is half the image shift amount between the image formed by the light beam 61 and the image formed by the second light beam 62 is calculated.
  • the image shift amount calculation unit 220f uses the second correlation waveform C20 to set the image shift amount ⁇ 2 between the image formed by the second light flux 62 and the images formed by the first and second light fluxes 61 and 62, ie, An image shift amount that is the remaining half of the image shift amount between the image formed by the first light beam 61 and the image formed by the second light beam 62 is calculated.
  • the image shift amount calculation unit 220f calculates the image shift amount ( ⁇ 1 + ⁇ 2) between the image formed by the first light beam 61 and the image formed by the second light beam 62 using the fifth correlation waveform C5.
  • the image shift amount calculation unit 220f calculates the image shift amount ⁇ 1 (or ⁇ 2) using the first added correlation waveform.
  • the image shift amount calculation unit 220f calculates the image shift amount ⁇ 1 (or ⁇ 2) using the second added correlation waveform.
  • the image shift amount adding unit 220g adds the first and second image shift amounts ⁇ 1 calculated from the first correlation waveform C1 and the image shift amount ⁇ 2 calculated from the second correlation waveform C2.
  • the image shift amount ( ⁇ 1 + ⁇ 2) of the image caused by the light beams 61 and 62 is calculated.
  • the image shift amount adding unit 220g adds the image shift amount ⁇ 1 calculated from the first correlation waveform C10 and the image shift amount ⁇ 2 calculated from the second correlation waveform C20, thereby obtaining the first and second image shift amounts.
  • the image shift amount ( ⁇ 1 + ⁇ 2) of the image due to the second light beams 61 and 62 is calculated.
  • the defocus amount calculation unit 220h converts the image shift amount into a defocus amount by using a conversion formula, that is, calculates the defocus amount by multiplying the image shift amount by a conversion coefficient (conversion coefficient).
  • the conversion coefficient for converting the image shift amount ⁇ 1 or ⁇ 2 to the defocus amount Def is twice the conversion coefficient K for converting the image shift amount ( ⁇ 1 + ⁇ 2) to the defocus amount Def, that is, 2K.
  • the lens movement amount calculation unit 220i calculates the movement amount of the focus lens 31b based on the defocus amount calculated by the defocus amount calculation unit 220h.
  • the lens control unit 32 of the interchangeable lens 3 drives the focus lens 31b to perform focus adjustment based on the calculated movement amount of the focus lens 31b.
  • the correlation calculation unit 220c performs the correlation calculation to obtain four first correlation waveforms C1, four second correlation waveforms C2, four third correlation waveforms C3, and four fourth correlation waveforms.
  • a total of 19 correlation waveforms (data) of the waveform C4, one first correlation waveform C10, one second correlation waveform C20, and one fifth correlation waveform C5 are generated.
  • the focus detection unit 220 selects a correlation waveform to be used for focus detection from these 19 correlation waveforms based on the determination result by the reliability determination unit 220d. That is, the focus detection unit 220 switches the correlation waveform used for focus detection according to the state of the subject image. Therefore, the camera 1 according to the present embodiment can perform accurate focus adjustment while suppressing a decrease in focus detection accuracy. Thereby, the camera 1 can improve the focus detection accuracy.
  • the focus detection unit 220 includes a focus detection area enlargement unit 220j that enlarges a focus detection area (AF area), and a focus detection signal output from a pixel in the enlarged focus detection area. Is used to calculate the image shift amount.
  • the focus detection area enlarging unit 220j can switch its function between enabled and disabled by the user operating the operation unit 25 or the like.
  • the focus detection area enlarging unit 220j is enabled, for example, the focus detection area 100 set by the area setting unit 212 and two focus detection areas 100 adjacent to the focus detection area 100 in the ⁇ Y direction.
  • the focus detection area is expanded to a total of three focus detection areas 100.
  • the pixel adder 220b uses the first to third focus detection signals output from the image sensor 22 for each of the three focus detection areas 100, and uses the mixed first focus detection signal and the mixed second focus detection signal. Is generated. Then, the pixel addition unit 220b adds the three mixed first focus detection signals generated for each focus detection area 100.
  • the added mixed first focus detection signal is the first focus detection signal of the first AF pixel 11 located in the same column of the three focus detection areas 100 and the first focus detection signal at the position of the second AF pixel 12. , Ie, a signal obtained by adding a total of 24 focus detection signals.
  • the pixel adding unit 220b adds the three mixed second focus detection signals generated for each focus detection area 100.
  • the added mixed second focus detection signal is also a signal obtained by adding a total of 24 focus detection signals.
  • the correlation calculation unit 220c calculates a fifth correlation waveform C50 by performing a correlation calculation between the mixed first focus detection signal and the mixed second focus detection signal added for 24 lines by the pixel addition unit 220b.
  • the image shift amount calculating unit 220f calculates the image shift amount ( ⁇ 1 + ⁇ 2) from the fifth correlation waveform C50, and the defocus amount calculating unit 220h calculates the defocus amount from the image shift amount.
  • FIG. 12 is a flowchart showing an operation example of the camera 1 of the present embodiment. An operation example of the camera 1 will be described with reference to the flowchart in FIG. The process illustrated in FIG. 12 is started based on a control program of the body control unit 210, for example, when the operation unit 25 is operated by a user to set an auto focus (AF) mode.
  • AF auto focus
  • the pseudo focus detection signal generation unit 220a is configured based on the first to third focus detection signals of the first and second AF pixels 11 and 12 and the imaging and AF pixel 13 selected by the pixel selection unit 213. , And first and second pseudo focus detection signals.
  • the pixel adder 220b performs an addition process using the first to third focus detection signals, and generates an addition first focus detection signal, an addition second focus detection signal, and an addition third focus detection signal. .
  • the pixel adder 220b adds the first focus detection signal and the first pseudo focus detection signal to generate a mixed first focus detection signal, and generates the mixed first focus detection signal and the second focus detection signal and the second pseudo focus.
  • the detection signals are added to generate a mixed second focus detection signal.
  • the correlation calculation unit 220c performs the above-described correlation calculation, and performs four first correlation waveforms C1, four second correlation waveforms C2, four third correlation waveforms C3, four fourth correlation waveforms C4, A total of 19 correlation waveforms of one first correlation waveform C10, one second correlation waveform C20, and one fifth correlation waveform C5 are generated.
  • the reliability determination unit 220d determines the reliability of the correlation waveforms of the four first correlation waveforms C1 and the four second correlation waveforms C2 among the 19 correlation waveforms. More specifically, the reliability determination unit 220d classifies the four first correlation waveforms C1 and the four second correlation waveforms C2 into four sets, and determines the reliability of the four correlation waveform pairs. The reliability determination unit 220d calculates the first correlation waveform C1 based on the focus detection signal of the first AF pixel line 402Ra shown in FIG. 4 and the first AF pixel among the second AF pixel lines 402La to 402Ld.
  • the second correlation waveform C2 based on the focus detection signal of the second AF pixel line 402La closest to the line 402Ra is regarded as one correlation waveform pair.
  • the reliability determination unit 220d determines the first correlation waveform C1 of the first AF pixel line 402Rb, the second correlation waveform C2 of the second AF pixel line 402Lb, and the first correlation waveform C1 of the first AF pixel line 402Rc.
  • the one correlation waveform C1 and the second correlation waveform C2 of the second AF pixel line 402Lc are each one correlation waveform pair.
  • the reliability determining unit 220d sets the first correlation waveform C1 of the first AF pixel line 402Rd and the second correlation waveform C2 of the second AF pixel line 402Ld as one correlation waveform pair.
  • the reliability determination unit 220d determines whether or not two correlation waveforms forming the correlation waveform pair out of the four correlation waveform pairs have a predetermined number (for example, two) of correlation waveform pairs having high reliability. judge. If the reliability determination unit 220d determines that there are a predetermined number or more of the correlation waveform pairs with high reliability among the four correlation waveform pairs, the process proceeds to step S120, and if the determination is negative in step S110, the process proceeds to step S210. Note that the reliability determination unit 220d may determine the reliability of each of the four first correlation waveforms C1 and the four second correlation waveforms C2. For example, the reliability determining unit 220d determines whether the number of correlated waveforms with high reliability is a predetermined number (for example, eight).
  • the reliability determination unit 220d determines that the reliability of the correlation waveform is low, and the minimum value of the correlation amount is If it is smaller than the predetermined threshold Th, it is determined that the reliability of the correlation waveform is high. If the reliability determination unit 220d determines that the correlation waveforms having high reliability among the eight correlation waveforms are the predetermined number, the process proceeds to step S120, and if a negative determination is made in S110, the process proceeds to step S210.
  • step S120 the focus detection unit 220 determines whether the focus detection area (AF area) 100 set by the area setting unit 212 is the center focus detection area 100a. If the central focus detection area 100a is set, the focus detection unit 220 proceeds to step S130, and if a negative determination is made in step S120, the process proceeds to step S170.
  • the focus detection unit 220 determines whether the signal processed in steps S100 to S120 is the focus detection signal output from the central focus detection area 100a, or the focus detection signal output from a part other than the central focus detection area 100a. The method of calculating the defocus amount is switched as described below. Note that the processing in step S120 may not be performed. In this case, the process may proceed to step S170 after step S110.
  • step S130 the correlation waveform processing unit 220e adds the first correlation waveform C1 of the plurality of correlation waveform pairs determined to have high reliability, and adds the second correlation waveform C2 of the plurality of correlation waveform pairs. to add.
  • step S140 the correlation waveform processing unit 220e inverts one of the added first correlation waveform C1 and second correlation waveform C2, and adds the inverted correlation waveform and the other correlation waveform (correlation waveform (No. 1).
  • step S150 the image shift amount calculator 220f calculates the image shift amount ⁇ 1 (or ⁇ 2) from the first added correlation waveform generated by the correlation waveform processor 220e.
  • step S160 the defocus amount calculation unit 220h converts the image shift amount ( ⁇ 1 + ⁇ 2) of the image by the first and second light beams 61 and 62 into the defocus amount by a conversion coefficient 2K twice as large as the conversion coefficient K. Is used to convert the image shift amount ⁇ 1 (or ⁇ 2) into a defocus amount Def.
  • the lens movement amount calculation unit 220i calculates the movement amount of the focus lens 31b based on the calculated defocus amount Def.
  • the lens controller 32 adjusts the focus by driving the focus lens 31b based on the calculated movement amount of the focus lens 31b.
  • the correlation waveform processing unit 220e determines that the reliability is The first correlation waveform C1 of the plurality of correlation waveform pairs determined to be high is added, and the second correlation waveform C2 of the plurality of correlation waveform pairs is added.
  • step S180 the image shift amount calculating unit 220f calculates the image shift amount ⁇ 1 from the added first correlation waveform C1. Further, the image shift amount calculating unit 220f calculates the image shift amount ⁇ 2 from the added second correlation waveform C2.
  • the image shift amount adding unit 220g calculates the image shift amount ( ⁇ 1 + ⁇ 2) of the image by the first and second light fluxes 61 and 62 by adding the image shift amount ⁇ 1 and the image shift amount ⁇ 2.
  • step S190 the defocus amount calculator 220h calculates the defocus amount Def by multiplying the image shift amount ( ⁇ 1 + ⁇ 2) calculated by the image shift amount adder 220g by the conversion coefficient K.
  • the lens movement amount calculation unit 220i calculates the movement amount of the focus lens 31b based on the defocus amount Def.
  • the lens controller 32 performs focus adjustment based on the calculated movement amount of the focus lens 31b.
  • the processing of steps S180 and S190 is performed instead of steps S140 to S160.
  • the reason for this is as follows.
  • the first correlation waveform C1 and the second correlation waveform C2 shown in FIG. 11 do not have left-right symmetry due to vignetting. The addition process cannot be used.
  • the addition processing is performed in step S130 or S170, and the image shift amount is calculated in step S150 or step S180 using the added first correlation waveform C1 and the added second correlation waveform C2. Is performed. Therefore, the calculation amount of the focus detection unit 220 can be reduced as compared with the case where the image shift amount is calculated from each of the plurality of first correlation waveforms C1 and the second correlation waveforms C2.
  • step S110 when the reliability determination unit 220d determines that there is no predetermined number or more of the correlation waveform pairs having high reliability among the four correlation waveform pairs, the process proceeds to step S210.
  • the reason why the correlation waveform pair having a high degree of reliability does not exist more than the predetermined number may be, for example, that the blur of the subject image in the set focus detection area 100 is relatively large. That is, if the blur of the subject image is relatively large, the subject image on the imaging and AF pixel 13 shown in FIG. 5C is formed by the first and second light fluxes 61 and 62, so that the blur is relatively large. . On the other hand, since the subject images on the first or second AF pixels 11 and 12 shown in FIGS.
  • 5A and 5B are respectively caused by the first or second light fluxes 61 and 62, blurring is caused by imaging and AF. It is smaller than the subject image on the pixel 13.
  • the waveforms of the first and second focus detection signals and the waveform of the third focus detection signal are relatively significantly different, and the reliability of the correlation waveform pair is reduced.
  • the reliability determination unit 220d determines that the third correlation waveform C3 based on the first focus detection signal and the second pseudo focus detection signal, the first pseudo focus detection signal and the second focus The reliability of the correlation waveform with the fourth correlation waveform C4 based on the detection signal is determined.
  • the reliability determination unit 220d classifies the four third correlation waveforms C3 and the four fourth correlation waveforms C4 into four sets, and determines the reliability of the four correlation waveform pairs.
  • the reliability determination unit 220d determines the third correlation waveform C3 of the first AF pixel line 402Ra shown in FIG. 4 and the closest of the second AF pixel lines 402La to 402Ld to the first AF pixel line 402Ra.
  • the fourth correlation waveform C4 of the second AF pixel line 402La is defined as one correlation waveform pair.
  • the reliability determination unit 220d calculates the third correlation waveform C3 of the first AF pixel line 402Rb, the fourth correlation waveform C4 of the second AF pixel line 402Lb, and the third correlation waveform C4 of the first AF pixel line 402Rc.
  • the third correlation waveform C3 and the fourth correlation waveform C4 of the second AF pixel line 402Lc are each one correlation waveform pair.
  • the reliability determination unit 220d sets the third correlation waveform C3 of the first AF pixel line 402Rd and the fourth correlation waveform C4 of the second AF pixel line 402Ld as one correlation waveform pair.
  • the reliability determination unit 220d determines whether or not two correlation waveforms forming the correlation waveform pair out of the four correlation waveform pairs have a predetermined number (for example, two) of correlation waveform pairs having high reliability. judge. If the reliability determination unit 220d determines that there are a predetermined number or more of the correlation waveform pairs having high reliability among the four correlation waveform pairs, the process proceeds to step S220, and if the determination is negative in step S210, the process proceeds to step S310. Note that the reliability determination unit 220d may determine the reliability of each of the four third correlation waveforms C3 and the four fourth correlation waveforms C4.
  • the reliability determining unit 220d determines whether the number of correlated waveforms with high reliability is a predetermined number (for example, eight). As described above, when the minimum value of the correlation amount calculated from the correlation waveform is larger than the predetermined threshold Th, the reliability determination unit 220d determines that the reliability of the correlation waveform is low, and the minimum value of the correlation amount is If it is smaller than the predetermined threshold Th, it is determined that the reliability of the correlation waveform is high. If the reliability determination unit 220d determines that the correlation waveforms with high reliability among the eight correlation waveforms are the predetermined number, the process proceeds to step S220, and if a negative determination is made in S210, the process proceeds to step S310.
  • a predetermined number for example, eight.
  • step S220 the correlation waveform processing unit 220e adds the third correlation waveforms C3 of the plurality of correlation waveform pairs determined to have high reliability, and adds the fourth correlation waveform C4 of the plurality of correlation waveform pairs. to add.
  • step S230 the image shift amount calculation unit 220f calculates the image shift amount ( ⁇ 1 + ⁇ 2) based on the added third correlation waveform C3, and calculates the image shift amount ( ⁇ 1 + ⁇ 2) based on the added fourth correlation waveform C4. Then, an average value of both image shift amounts is calculated.
  • step S240 the defocus amount calculation unit 220h calculates the defocus amount Def by multiplying the average image shift amount ( ⁇ 1 + ⁇ 2) calculated by the image shift amount addition unit 220g by the conversion coefficient K.
  • the lens movement amount calculation unit 220i calculates the movement amount of the focus lens 31b based on the defocus amount Def.
  • the lens controller 32 performs focus adjustment based on the calculated movement amount of the focus lens 31b.
  • the focus detection unit 220 outputs the third correlation waveform C3 based on the first focus detection signal and the second pseudo focus detection signal and the first pseudo focus
  • the defocus amount is calculated using the fourth correlation waveform C4 based on the detection signal and the second focus detection signal. For this reason, the focus detection accuracy can be improved as compared with the case where the defocus amount is calculated using the first and second focus detection signals and the third focus detection signal.
  • the focus detection unit 220 adds the third and fourth correlation waveforms C3 and C4 in step S220, and calculates the added third correlation waveform C3 and the added fourth correlation waveform C4. To calculate the defocus amount. For this reason, the S / N ratio can be improved and the focus detection accuracy can be improved as compared with the case where the defocus amount is calculated using one third correlation waveform C3 or one fourth correlation waveform C4. be able to.
  • step S210 the reliability determination unit 220d determines that the correlation waveform pair of the third correlation waveform C3 and the fourth correlation waveform C4 does not have a predetermined number of correlation waveform pairs with high reliability. If it is determined, the process proceeds to step S310.
  • One reason why the reliability of the first and second correlation waveforms C1 and C2 is low and the reliability of the third and fourth correlation waveforms C3 and C4 is low is, for example, that the object in the focus detection area 100 is set. This is probably because the image has low brightness and the first to third focus detection signals contain much noise. Therefore, after step S310, the focus detection signal added by the pixel addition unit 220b is used, that is, a focus detection signal with an improved SN ratio is used.
  • step S310 the reliability determination unit 220d determines, among the 19 correlation waveforms, a first correlation waveform C10 based on the added first focus detection signal and the added third focus detection signal, and an added second focus. The reliability of each correlation waveform of the second correlation waveform C20 based on the detection signal and the added third focus detection signal is determined. If the reliability determining unit 220d determines that both the first correlation waveform C10 and the one second correlation waveform C20 have high reliability, the process proceeds to step S320. If the determination is negative in step S310, the process proceeds to step S410. .
  • step S320 if the central focus detection area 100a has been set by the area setting section 212, the focus detection section 220 proceeds to step S330. If a negative determination is made in step S320, the focus detection section 220 proceeds to step S360.
  • step S330 the correlation waveform processing unit 220e inverts one of the first correlation waveform C10 and the second correlation waveform C20, and adds the inverted correlation waveform to the other correlation waveform (second correlation waveform). (Additional correlation waveform).
  • step S340 the image shift amount calculator 220f calculates the image shift amount ⁇ 1 (or ⁇ 2) from the second added correlation waveform generated by the correlation waveform processor 220e.
  • step S350 the defocus amount calculation unit 220h converts the image shift amount ⁇ 1 (or ⁇ 2) into the defocus amount Def using the conversion coefficient 2K.
  • the lens movement amount calculation unit 220i calculates the movement amount of the focus lens 31b based on the defocus amount Def.
  • the lens control unit 32 performs focus adjustment based on the amount of movement of the focus lens 31b.
  • the image shift amount calculation unit 220f sets the first Is calculated from the correlation waveform C10. Further, the image shift amount calculation unit 220f calculates the image shift amount ⁇ 2 from the second correlation waveform C20.
  • the image shift amount adding unit 220g calculates the image shift amount ( ⁇ 1 + ⁇ 2) of the image by the first and second light fluxes 61 and 62 by adding the image shift amount ⁇ 1 and the image shift amount ⁇ 2.
  • step S370 the defocus amount calculation unit 220h calculates the defocus amount Def by multiplying the image shift amount ( ⁇ 1 + ⁇ 2) calculated by the image shift amount addition unit 220g by the conversion coefficient K.
  • the lens movement amount calculation unit 220i calculates the movement amount of the focus lens 31b based on the defocus amount Def.
  • the lens control unit 32 performs focus adjustment based on the amount of movement of the focus lens 31b.
  • step S310 when the reliability determination unit 220d determines that the reliability of the first correlation waveform C10 or the second correlation waveform C20 is low in step S310, the process proceeds to step S410.
  • the reason why the reliability of the first correlation waveform C10 or the second correlation waveform C20 is low is that, for example, the blur of the subject image in the set focus detection area 100 is relatively large, and therefore, the first and second focus points are different. It is conceivable that the waveform of the detection signal and the waveform of the third focus detection signal are relatively different.
  • step S410 the reliability determination unit 220d determines the reliability of the fifth correlation waveform C5 based on the mixed first focus detection signal and the mixed second focus detection signal among the 19 correlation waveforms. I do. If the reliability determining unit 220d determines that the reliability of the fifth correlation waveform C5 is high, the process proceeds to step S420. If the negative determination is made in step S310, the process proceeds to step S510.
  • step S420 the image shift amount calculator 220f calculates the image shift amount ( ⁇ 1 + ⁇ 2) from the fifth correlation waveform C5.
  • step S430 the defocus amount calculation unit 220h calculates the defocus amount Def by multiplying the image shift amount ( ⁇ 1 + ⁇ 2) calculated by the image shift amount addition unit 220g by the conversion coefficient K.
  • the lens movement amount calculation unit 220i calculates the movement amount of the focus lens 31b based on the defocus amount Def.
  • the lens control unit 32 performs focus adjustment based on the amount of movement of the focus lens 31b.
  • step S410 when the reliability determination unit 220d determines that the reliability of the fifth correlation waveform C5 is low, the process proceeds to step S510.
  • the reason why the reliability of the fifth correlation waveform C5 is low is that, for example, the subject image in the set focus detection area 100 has a very low luminance, and the first to third focus detection signals generate very much noise. It is thought to include.
  • step S510 when the focus detection area enlarging unit 220j is valid, the focus detection unit 220 proceeds to step S520. If a negative determination is made in step S510, the calculation of the defocus amount is not performed.
  • step S520 the pixel addition unit 220b generates the mixed first focus detection signal and the mixed second focus detection signal in the focus detection area enlarged by the focus detection area enlargement unit 220j as described above.
  • the pixel adding unit 220b adds the generated three mixed first focus detection signals and adds the generated three mixed second focus detection signals.
  • the correlation calculation unit 220c generates a fifth correlation waveform C50 based on the added first mixed focus detection signal and second mixed focus detection signal.
  • the image shift amount calculation unit 220f calculates the image shift amount ( ⁇ 1 + ⁇ 2) from the fifth correlation waveform C50.
  • step S530 the defocus amount calculation unit 220h calculates the defocus amount Def by multiplying the image shift amount ( ⁇ 1 + ⁇ 2) calculated by the image shift amount addition unit 220g by the conversion coefficient K.
  • the lens movement amount calculation unit 220i calculates the movement amount of the focus lens 31b based on the defocus amount Def.
  • the lens control unit 32 performs focus adjustment based on the amount of movement of the focus lens 31b.
  • FIG. 13 is a diagram illustrating a configuration of a pixel of the image sensor 22 according to the first embodiment.
  • the pixel 13 includes a photoelectric conversion unit 42, a transfer unit 52, a reset unit 53, a floating diffusion (FD) 54, an amplification unit 55, and a selection unit 56.
  • the photoelectric conversion unit 42 is a photodiode PD, converts incident light into electric charges, and accumulates the photoelectrically converted electric charges.
  • the transfer unit 52 includes a transistor M1 controlled by the signal TX, and transfers the charge photoelectrically converted by the photoelectric conversion unit 42 to the FD 54.
  • the transistor M1 is a transfer transistor.
  • the capacitance C of the FD 54 stores (holds) the charge transferred to the FD 54.
  • the amplifying unit 55 outputs a signal based on the electric charge accumulated in the capacitance C of the FD 54.
  • the amplification unit 55 and the selection unit 56 constitute an output unit that generates and outputs a signal based on the charge generated by the photoelectric conversion unit 42.
  • the reset unit 53 includes a transistor M2 controlled by the signal RST, discharges the electric charge accumulated in the FD 54, and resets the voltage of the FD 54.
  • the transistor M2 is a reset transistor.
  • the selection unit 56 includes a transistor M4 controlled by the signal SEL, and electrically connects or disconnects the amplification unit 55 and the vertical signal line 60.
  • the transistor M4 is a selection transistor.
  • the charges photoelectrically converted by the photoelectric conversion unit 42 are transferred to the FD 54 by the transfer unit 52. Then, a signal corresponding to the 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 photoelectrically converted by the photoelectric conversion unit 42.
  • the signal output from the imaging pixel 13 is output to the body control unit 210 after being converted into a digital signal.
  • the circuit configuration of the first AF pixel 11 (11a to 11c) and the second AF pixel 12 (12a to 12c) are the same as the circuit configuration of the imaging pixel 13.
  • the signals output from the first AF pixel 11 and the second AF pixel 12 are converted into digital signals and then output to the body control unit 210 as signals used for focus detection.
  • FIG. 14 is a diagram illustrating a configuration example of the imaging element according to the first embodiment.
  • the imaging element 22 includes a plurality of imaging pixels 13, a first AF pixel 11 and a second AF pixel 12, a vertical control unit 70, and a plurality of column circuit units 80.
  • FIG. 14 for simplicity of description, only 128 pixels of 8 pixels in the row direction ( ⁇ X direction) ⁇ 16 pixels in the column direction ( ⁇ Y direction) are shown.
  • the pixel at the upper left corner is the imaging pixel 13 (1, 1) in the first row and the first column
  • the imaging pixel in the lower right corner is the imaging pixel 13 (16, 8) in the 16th row and the 8th column.
  • the image sensor 22 is provided with a plurality of vertical signal lines 60 (vertical signal lines 60a to 60h).
  • the plurality of vertical signal lines 60 are connected to pixel columns (first to eighth columns), which are columns of a 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 a plurality of imaging pixels 13 arranged in the same column and output signals of the connected imaging pixels 13, respectively.
  • the vertical signal lines 60b, 60d, 60f, and 60h are connected to the plurality of imaging pixels 13 and the plurality of first AF pixels 11 and the plurality of second AF pixels 12 arranged in the same column, and the connected imaging pixels 13 and It outputs signals of the first AF pixel 11 and the second AF pixel 12, respectively.
  • FIG. 14 shows, for example, a circuit configuration of a part of the first small area 91 in the focus detection area 100.
  • the second and third small areas 92 and 93 have the same configuration as the configuration shown in FIG.
  • the vertical control unit 70 is provided in common for a plurality of pixel columns.
  • the vertical control unit 70 supplies the signal TX, the signal RST, and the signal SEL shown in FIG. 13 to each pixel to control the operation of each pixel.
  • the vertical control unit 70 supplies a signal to the gate of each transistor of the pixel to turn on the transistor (connected state, conductive state, short-circuit state) or off state (disconnected state, non-conductive state, open state, cut-off state).
  • the column circuit section 80 includes an analog / digital conversion section (AD conversion section), converts an analog signal input from each pixel via the vertical signal line 60 into a digital signal, and outputs the digital signal.
  • the pixel signal converted into the digital signal is input to a signal processing unit (not shown), and subjected to signal processing such as correlated double sampling and processing for correcting the signal amount. Is output to
  • the body control unit 210 controls the vertical control unit 70 to sequentially select all the pixel groups and read out the signal of each pixel, and the first readout mode in which the AF pixels are arranged (first and second pixel groups).
  • the reading of the signal of each pixel of the second AF pixel line) and the reading of the signal of each pixel of a pixel group (first pixel group 401 and second pixel group 402) where no AF pixel is arranged are performed separately.
  • the second read mode is performed.
  • the vertical control unit 70 sequentially selects a plurality of pixel groups and causes each pixel to output a signal.
  • the vertical driving unit 70 sequentially selects the pixel groups from the first row to the sixteenth row.
  • the vertical control unit 70 outputs a signal from each pixel of the selected pixel group to the vertical signal line 60.
  • the vertical drive unit 70 turns on the selection units 56 of the R pixels 13 (1, 1) to G pixels 13 (1, 8), which are the pixels of the first pixel group 401 in the first row, respectively.
  • the vertical drive unit 70 turns off the selection units 56 of the pixels in rows other than the first row.
  • the signals of the R pixels 13 (1, 1) to G pixels 13 (1, 8) in the first row are respectively supplied to the vertical pixels connected to each pixel via the selection unit 56 of each pixel.
  • the signal is output from the signal line 60a to the vertical signal line 60h.
  • the vertical control unit 70 controls the selection unit 56 of the G pixel 13 (2, 1) to the first AF pixel 11 (2, 8), which are the pixels of the first AF pixel line 402Ra in the second row. Turn on. In addition, the vertical control unit 70 turns off the selection units 56 of the pixels in rows other than the second row. Thus, the signals of the G pixels 13 (2, 1) to the first AF pixels 11 (2, 8) in the second row are output to the vertical signal lines 60a to 60h, respectively. Similarly, the vertical control unit 70 sequentially selects the pixel groups on the third and subsequent rows one by one in the order of the third row, the fourth row, the fifth row, and the sixth row. The vertical control unit 70 outputs a signal from each pixel of the selected pixel group to the vertical signal line 60.
  • the vertical control unit 70 reads a signal from each pixel of all the pixel groups.
  • the signal read from each pixel is read by the body control unit 210 after being subjected to signal processing by the column circuit unit 80 and the like.
  • the vertical drive unit 70 reads out the signals of the respective pixels of the first and second AF pixel lines and sets each of the pixel groups in which the AF pixels are not arranged. The reading of the pixel signal is performed separately.
  • the vertical drive unit 70 controls the AF pixel selected by the pixel selection unit 213 and the imaging in one (or a plurality) of the focus detection areas 100 set by the area setting unit 212.
  • the first and second AF pixel lines in which the AF pixels are arranged are sequentially selected from the top row to the bottom row, and the signal of each pixel is read.
  • the vertical driving unit 70 sequentially selects a pixel group in which AF pixels are not arranged from the top row to the bottom row, and outputs a signal of each pixel. Is read.
  • the signal of each pixel of the AF pixel line is read separately from the signal of each pixel of the pixel group in which the AF pixel is not arranged, so that the signal used for focus detection is efficiently used.
  • the burden of signal processing for AF can be reduced.
  • the camera 1 according to the present embodiment reads out the signal of the AF pixel selected based on the exit pupil distance of the imaging optical system 31, and performs focus detection processing. Therefore, highly accurate focus detection can be performed.
  • the body control unit 210 when setting the second readout mode and reading out a signal from a pixel group in which AF pixels are not arranged, the body control unit 210 thins out pixels in a specific row or column among all imaging pixels. A signal may be read out or a thinning-out reading may be performed. When performing the thinning-out reading, the body control unit 210 selects an imaging pixel in a specific row or column among all the imaging pixels, and reads a signal from the selected imaging pixel. The body control unit 210 controls the vertical control unit 70 to skip a signal of a pixel in a specific row or column, thereby reading out the signal at high speed. Note that the body control unit 210 may add and read out signals of a plurality of imaging pixels.
  • step S100 the focus detection unit 220 outputs the first and second pseudo focus detection signals, the first, second, and third addition focus detection signals, and the mixed first and second focus detection signals.
  • An example has been described in which a mixed second focus detection signal and 19 correlation waveforms based on these signals are generated.
  • the focus detection unit 220 may calculate a focus detection signal and a correlation waveform necessary for the determination process before each of the determination processes in steps S110, S210, S310, and S410.
  • step S100 the focus detection unit 220 generates four first correlation waveforms C1 and four second correlation waveforms C2.
  • the focus detection unit 220 When a negative determination is made in step S100 and the process proceeds to step S210, the focus detection unit 220 generates the first and second pseudo focus detection signals, and outputs the four third correlation waveforms C3 and the four fourth correlations. A waveform C4 is generated.
  • the focus detection unit 220 When a negative determination is made in step S210 and the process proceeds to step S310, the focus detection unit 220 generates addition first, addition second, and addition third focus detection signals, and generates one first correlation waveform C10 and One second correlation waveform C20 is generated. Further, when a negative determination is made in step S310 and the process proceeds to step S410, the focus detection unit 220 generates the mixed first and second focus detection signals and generates one fifth correlation waveform C5.
  • step S110 the reliability determination unit 220d determines whether there are two or more correlation waveform pairs with high reliability, for example, and determines in step S120 or step S120 according to the determination result.
  • the example of proceeding to step S210 has been described.
  • the criterion for the number of correlation waveform pairs for determining which of step S120 and step S210 to proceed to is not limited to two or more, and may be any number.
  • the reliability determination unit 220d may determine whether there are three or more correlation waveform pairs with high reliability.
  • step S110 the reliability determination unit 220d may determine whether or not there is one or more correlation waveform pairs with high reliability. At this time, if there is only one correlation waveform pair with high reliability, the process of adding the correlation waveform in step S130 or step S170 is not required. For this reason, the amount of calculation in the focus detection unit 220 can be reduced.
  • the reference of the number of correlation waveform pairs for determining which of step S220 and step S310 to proceed to is not limited to two or more, but may be any number. May be.
  • the reliability determination unit 220d may determine whether there is one or more correlation waveform pairs with high reliability. At this time, if there is only one correlation waveform pair with high reliability, the process of adding the correlation waveform in step S220 becomes unnecessary, and the amount of calculation can be reduced.
  • step S310 the reliability determining unit 220d determines whether both one first correlation waveform C10 and one second correlation waveform C20 have high reliability, and determines the determination result.
  • the process proceeds to step S320 or step S410 according to the above is described.
  • the focus detection unit 220 calculates the image shift amount ⁇ 1 (or ⁇ 2) from the one of the correlation waveforms instead of the processing of steps S320 to S370, and performs conversion.
  • the defocus amount Def is calculated using the coefficient 2K.
  • the correlation waveform processing unit 220e performs the first correlation of the plurality of correlation waveform pairs for which the two correlation waveforms forming the correlation waveform pair are both determined to have high reliability.
  • the example in which the waveform C1 is added and the second correlation waveform C2 of the plurality of correlation waveform pairs is added has been described.
  • the correlation waveform processing unit 220e instead of the processing in steps S130 and S170, the correlation waveform processing unit 220e has determined that the reliability is high irrespective of whether or not both of the two correlation waveforms forming the correlation waveform pair have high reliability. All the first correlation waveforms C1 may be added, and all the second correlation waveforms C2 determined to have high reliability may be added.
  • the focus detection unit 220 determines each of the added first correlation waveform C1 and second correlation waveform C2 according to the number of additions of the first correlation waveform C1 and the number of additions of the second correlation waveform C2. For example, a process for correcting the signal level may be performed.
  • the correlation waveform processing unit 220e may perform the addition processing of the first correlation waveform C1 and the addition processing of the second correlation waveform C2 regardless of the determination result by the reliability determination unit 220d. In this case, in steps S130 and S170, the correlation waveform processing unit 220e adds, for example, four first correlation waveforms C1. Further, the correlation waveform processing section 220e adds the four second correlation waveforms C2.
  • the correlation waveform processing unit 220e inverts one of the first correlation waveform C1 and the second correlation waveform C2 for each of the plurality of correlation waveform pairs, and outputs the inverted correlation waveform and the other correlation waveform.
  • the image shift amount calculation unit 220f calculates the image shift amount ⁇ 1 (or ⁇ 2) from each of the generated plurality of added correlation waveforms.
  • the defocus amount calculation unit 220h calculates the defocus amount Def by multiplying the average value of the calculated plurality of image shift amounts ⁇ 1 (or ⁇ 2) by a double conversion coefficient 2K.
  • the focus detection unit 220 converts the image shift amount calculated from each of the plurality of correlation waveform pairs into a defocus amount, and uses the average value of the calculated plurality of defocus amounts Def to move the focus lens 31b. The amount may be calculated.
  • the focus detection unit 220 calculates an image shift amount from each of the first and second correlation waveforms C1 and C2 of the plurality of correlation waveform pairs instead of the processing of steps S170 to S180, and calculates the calculated plurality of image shift amounts.
  • the defocus amount may be calculated based on the amount.
  • the image shift amount calculation unit 220f calculates the image shift amount ⁇ 1 from each of the first correlation waveforms C1 of the plurality of correlation waveform pairs, and also calculates the second correlation waveform of the plurality of correlation waveform pairs.
  • An image shift amount ⁇ 2 is calculated from each of C2.
  • the image shift amount adding unit 220g calculates the image shift amount ( ⁇ 1 + ⁇ 2) by adding the average value of the plurality of image shift amounts ⁇ 1 and the average value of the plurality of image shift amounts ⁇ 2.
  • the defocus amount calculation unit 220h calculates the defocus amount Def by multiplying the calculated image shift amount ( ⁇ 1 + ⁇ 2) by the conversion coefficient K.
  • the focus detection unit 220 converts each of the average value of the plurality of image shift amounts ⁇ 1 and the average value of the plurality of image shift amounts ⁇ 2 into a defocus amount, and calculates the average value of the calculated plurality of defocus amounts Def. May be used to calculate the amount of movement of the focus lens 31b.
  • the focus detection unit 220 calculates an image shift amount from each of the third and fourth correlation waveforms C3 and C4 of the plurality of correlation waveform pairs instead of the processing of steps S220 to S230, and calculates the calculated image shift amounts.
  • the defocus amount may be calculated based on the amount.
  • the image shift amount calculation unit 220f calculates the image shift amount ( ⁇ 1 + ⁇ 2) from each of the third correlation waveforms C3 of the plurality of correlation waveform pairs, and also calculates the fourth correlation waveform pair.
  • An image shift amount ( ⁇ 1 + ⁇ 2) is calculated from each of the correlation waveforms C4.
  • step S240 the defocus amount calculation unit 220h calculates the defocus amount Def by multiplying the average value of all the calculated image shift amounts ( ⁇ 1 + ⁇ 2) by the conversion coefficient K.
  • the focus detection unit 220 calculates the average value of the image shift amount ( ⁇ 1 + ⁇ 2) calculated from each of the third correlation waveforms C3 and the image shift amount ( ⁇ 1 + ⁇ 2) calculated from each of the fourth correlation waveforms C4.
  • the average value may be converted into a defocus amount, and the moving amount of the focus lens 31b may be calculated using the average value of the calculated plurality of defocus amounts Def.
  • the focus detection unit 220 calculates an image shift amount from each of the added first correlation waveform C1 and second correlation waveform C2 instead of the processing in steps S140 to S150, and calculates the two image shift amounts respectively.
  • the average value of the two calculated defocus amounts Def may be calculated by converting into the defocus amount.
  • the focus detection unit 220 calculates the movement amount of the focus lens 31b based on the average value of the defocus amount Def.
  • the focus detection unit 220 calculates an image shift amount from each of the added first correlation waveform C1 and second correlation waveform C2 instead of the processing of steps S170 to S180, and calculates the two image shift amounts respectively.
  • the average value of the two calculated defocus amounts Def may be calculated by converting into the defocus amount.
  • the focus detection unit 220 calculates the movement amount of the focus lens 31b based on the average value of the defocus amount Def.
  • the focus detection unit 220 calculates an image shift amount from each of the added third correlation waveform C3 and fourth correlation waveform C4 instead of the processing of steps S220 to S230, and calculates the calculated two image shift amounts. May be converted into defocus amounts, and an average value of the two calculated defocus amounts Def may be calculated. In this case, in step S240, the focus detection unit 220 calculates the movement amount of the focus lens 31b based on the average value of the defocus amount Def.
  • the reliability determination unit 220d determines the reliability (reliability) of the correlation waveform based on the minimum value of the correlation amount has been described, but the method of determining the reliability is not limited to this. Absent.
  • the reliability determination unit 220d may determine the reliability of the correlation waveform based on the shift amount at which the correlation amount becomes minimum. For example, the reliability determining unit 220d determines that the reliability of the correlation waveform is low when the shift amount at which the correlation amount is minimum is larger than a predetermined threshold, and determines that the shift amount at which the correlation amount is minimum is at a predetermined threshold value. If it is smaller, it is determined that the reliability of the correlation waveform is high.
  • the pixel selection unit 213 determines the first to third small areas 91 for the focus detection area 100 set by the area setting unit 212 based on the exit pupil distance of the imaging optical system 31.
  • the AF pixel and the imaging / AF pixel belonging to any one of Nos. 93 are selected.
  • the focus detection unit 220 calculates the defocus amount based on the focus detection signal output from the AF pixel and the imaging / AF pixel of the selected one small area. As described above, in the camera 1, the focus detection is performed on one small area where the AF pixel suitable for the exit pupil distance of the imaging optical system 31 and the imaging / AF pixel are arranged.
  • the body control unit 210 may determine whether to perform focus detection using the phase difference detection method or focus detection using the contrast detection method based on the state of the subject such as the size of the subject.
  • the body control unit 210 includes a subject detection unit that detects a specific subject as a main subject by subject recognition technology or the like, and performs focus detection processing or contrast detection based on a phase difference detection method based on the detection result by the subject detection unit. Select the focus detection processing of the system.
  • the body control unit 210 performs focus detection using the phase difference detection method. Do.
  • the body control unit 210 performs focus detection using the contrast detection method.
  • the focus detection is performed using the signals output from the imaging pixels also for the remaining two small areas described above, so that the focus detection accuracy decreases when the main subject image is relatively small. Can be prevented.
  • the body control unit 210 sets the focus detection area 100 including the first to third small areas 91 to 93 as the focus detection area for performing focus detection.
  • the size of the focus detection area may be smaller than the size of the focus detection area 100 including the first to third small areas 91 to 93.
  • the size of the AF frame displayed on the display unit 24 and selectable by operating the operation unit 25 may be a size corresponding to one small area of the focus detection area 100.
  • the body control unit 210 does not perform the phase difference detection type focus detection.
  • focus detection using a contrast detection method may be performed.
  • the imaging device described in the above-described embodiment and the modified examples may be applied to a camera, a smartphone, a tablet, a camera built in a PC, an in-vehicle camera, a camera mounted on an unmanned aerial vehicle (drone, radio-controlled machine, etc.), and the like. Good.
  • Imaging optical system 31a: zoom lens, 31b: focus lens, 31c: aperture, 32: lens control unit, 33: lens memory, 42: photoelectric conversion unit, 44: microlens, 210: body control unit, 211: image data Generation unit, 212: region setting unit, 213: pixel selection unit, 220: focus detection unit, 220a: pseudo focus detection signal generation unit, 220b: pixel addition unit, 220c: correlation operation unit, 220d: reliability determination unit, 220e ... Correlation waveform processing section, 220f image shift amount calculation section, 220g image shift amount addition section, 220h defocus amount calculation section, 220i lens movement amount calculation section, 220 ... focus detection area enlarged portion

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Optics & Photonics (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Focusing (AREA)
  • Automatic Focus Adjustment (AREA)
  • Studio Devices (AREA)
  • Structure And Mechanism Of Cameras (AREA)

Abstract

La présente invention concerne un dispositif de détection de mise au point qui comprend : une unité de capture d'image qui comprend un premier pixel qui convertit de manière photoélectrique la lumière qui a traversé une première région d'un système optique et qui émet un premier signal, et un second pixel qui convertit de manière photoélectrique la lumière qui a traversé une seconde région, qui comprend la première région, du système optique et qui émet un second signal ; et une unité de détection qui exécute une détection de mise au point pour le système optique.
PCT/JP2019/028477 2018-07-20 2019-07-19 Dispositif de détection de mise au point, dispositif de capture d'image et lentille interchangeable WO2020017641A1 (fr)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009141390A (ja) * 2007-12-03 2009-06-25 Nikon Corp 撮像素子および撮像装置
JP2015022028A (ja) * 2013-07-16 2015-02-02 キヤノン株式会社 撮像装置
JP2016038414A (ja) * 2014-08-05 2016-03-22 キヤノン株式会社 焦点検出装置およびその制御方法、並びに撮像装置

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Publication number Priority date Publication date Assignee Title
CN106062608B (zh) * 2014-03-25 2018-07-31 富士胶片株式会社 摄像装置及对焦控制方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009141390A (ja) * 2007-12-03 2009-06-25 Nikon Corp 撮像素子および撮像装置
JP2015022028A (ja) * 2013-07-16 2015-02-02 キヤノン株式会社 撮像装置
JP2016038414A (ja) * 2014-08-05 2016-03-22 キヤノン株式会社 焦点検出装置およびその制御方法、並びに撮像装置

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