JP5685892B2 - Focus detection device, focus adjustment device, and imaging device - Google Patents

Description

  The present invention relates to a focus detection device, a focus adjustment device, and an imaging device.

  A focus detection apparatus of the so-called pupil division type phase difference detection method as described below is known. In the focus detection device, focus detection pixels including a microlens and a pair of photoelectric conversion units disposed behind the microlens are arranged on a planned focal plane of the photographing lens. The focus detection pixel generates a pair of image signals corresponding to the pair of images formed by the pair of focus detection light beams passing through the optical system. The focus detection device detects the focus adjustment state of the photographing lens by detecting the amount of image shift between the pair of image signals.

  In this type of focus detection device, when detecting an image shift amount (phase difference) between a pair of image signals, one of the pair of image signals is fixed (as a reference), and the other image signal is fixed. The degree of correlation is calculated while shifting the signal one pixel at a time. The defocus amount (focus adjustment state) of the optical system is detected according to the shift amount showing the maximum correlation degree among the correlation degrees thus calculated (see, for example, Patent Document 1).

JP 2009-151155 A

  However, in the conventional focus detection apparatus described above, when the focus detection position is in the vicinity of the shooting screen, the light amount balance between the pair of focus detection light beams may be lost and the output levels of the pair of image signals may be different. . In such a case, there is a problem that the detection accuracy of the image shift amount may be lowered.

(1) focus detecting apparatus according to claim 1, passing through the respective regions of a pair of the exit pupil of the optical system, a first light beam, which is one of the light beam, and the other light flux than the first light flux A light receiving unit that receives a second light beam having a large amount of vignetting, and outputs a first signal corresponding to the first light beam and a second signal corresponding to the second light beam, the light amount being larger than the second light beam; Using the first signal as a reference, the correlation between the first signal and the second signal is calculated by correlation calculation while displacing the second signal with respect to the first signal, and the first and second signals are calculated. A shift amount detecting means for detecting a shift amount of the signal and a focus detecting means for detecting a focus adjustment state of the optical system based on the shift amount are provided.
(2) the focusing device according to claim 1 2, and the focus detection device according to any one of claims 1 to 11, wherein the optical in accordance with the focusing condition detected by the focus detection means And a focus adjusting means for adjusting the focus of the system.
(3) The imaging apparatus according to claim 1 3, characterized in that it comprises a focusing device according to claim 1 2.

  According to the present invention, it is possible to prevent a decrease in detection accuracy of the focus adjustment state of the optical system.

It is a figure which shows the structure of the digital still camera which has the focus detection apparatus of one Embodiment. It is a figure which shows the focus detection area on the imaging | photography screen set to the scheduled image formation surface of an interchangeable lens. It is a front view which shows the detailed structure of an image pick-up element. It is sectional drawing for demonstrating the state of the focus detection light beam which a focus detection pixel receives. It is sectional drawing for demonstrating the state of the focus detection light beam which a focus detection pixel receives. It is a figure which shows the relationship of a pair of focus detection light beam which arrives at each focus detection area from a pair of ranging pupil. It is the figure which showed how a pair of focus detection light flux was restrict | limited by the exit pupil of an interchangeable lens. It is the figure which showed the pair of focus detection light flux which arrives at a focus detection area in the cross section in the surface where the exit pupil is arrange | positioned. It is the figure which showed the pair of focus detection light flux which arrives at a focus detection area in the cross section in the surface where the exit pupil is arrange | positioned. It is a flowchart which shows operation | movement of a digital still camera. It is the figure which showed the image data which the arrangement | sequence of a pair of focus detection pixel which light-receives a pair of focus detection light beam outputs. It is a figure which shows the focus detection area on the imaging | photography screen set to the scheduled image formation surface of an interchangeable lens. It is a front view which shows the detailed structure of an image pick-up element. It is a figure which shows the structural example of the focus detection apparatus of a re-imaging pupil division type phase difference detection system.

  As an imaging apparatus having a focus detection apparatus according to an embodiment of the present invention, an interchangeable lens digital still camera will be described as an example. FIG. 1 is a cross-sectional view showing a configuration of a digital still camera according to an embodiment. A digital still camera 201 according to the present embodiment includes an interchangeable lens 202 and a camera body 203, and the interchangeable lens 202 is attached to the camera body 203 via a mount unit 204. An interchangeable lens 202 having various photographing optical systems can be attached to the camera body 203 via a mount unit 204.

  The interchangeable lens 202 includes a lens 209, a zooming lens 208, a focusing lens 210, a diaphragm 211, a lens drive control device 206, and the like. The lens drive control device 206 includes a microcomputer (not shown), a memory, a drive control circuit, and the like, and adjusts the focus of the focusing lens 210, drive control for adjusting the aperture diameter of the stop 211, zooming lens 208, and focusing lens. 210 and the state of the diaphragm 211 are detected. In addition, transmission of lens information and reception of camera information (defocus amount, aperture value, etc.) are performed by communication with a body drive control device 214 described later. The aperture 211 forms an aperture having a variable aperture diameter at the center of the optical axis in order to adjust the amount of light and the amount of blur.

  The camera body 203 includes an image sensor 212, a body drive control device 214, a liquid crystal display element drive circuit 215, a liquid crystal display element 216, an eyepiece lens 217, a memory card 219, and the like. In the imaging element 212, imaging pixels are two-dimensionally arranged, and focus detection pixels are incorporated in portions corresponding to focus detection positions (focus detection areas). Details of the image sensor 212 will be described later.

  The body drive control device 214 includes a microcomputer, a memory, a drive control circuit, and the like. The body drive control device 214 repeatedly performs exposure control of the image sensor 212 and readout of the pixel signal from the image sensor 212, focus detection calculation based on the pixel signal of the focus detection pixel, and focus adjustment of the interchangeable lens 202, Processing and recording of image signals, camera operation control, etc. The body drive control device 214 communicates with the lens drive control device 206 via the electrical contact 213 to receive lens information and send camera information.

  The liquid crystal display element 216 functions as an electric view finder (EVF). The liquid crystal display element driving circuit 215 displays a through image on the liquid crystal display element 216 based on the image data read from the image sensor 212, and the photographer can observe the through image through the eyepiece 217. The memory card 219 is an image storage that stores image data captured by the image sensor 212.

  A subject image is formed on the light receiving surface of the image sensor 212 by the light beam that has passed through the interchangeable lens 202. This subject image is photoelectrically converted by the image sensor 212, and the pixel signal (imaging signal) of the imaging pixel and the pixel signal (focus detection signal) of the focus detection pixel are sent to the body drive control device 214.

  As will be described later with reference to FIG. 10, the body drive control device 214 calculates the image shift amount of the pair of image data based on the pixel signal (focus detection signal) from the focus detection pixel of the image sensor 212, and the image shift. A defocus amount is calculated based on the amount. When calculating the image shift amount, one of the pair of image data is selected as fixed data. When the body drive control device 214 detects the focus adjustment state of the interchangeable lens 202 based on the defocus amount, and determines that the focus adjustment state is not close to the in-focus state, the body drive control device 214 sends this defocus amount to the lens drive control device 206. In 206, the focusing lens 210 and the aperture 211 are driven. The body drive control device 214 processes the pixel signal from the image sensor 212 to generate image data, stores it in the memory card 219, and drives the through image signal read from the image sensor 212 to drive the liquid crystal display element. The image is sent to the circuit 215 and the through image is displayed on the liquid crystal display element 216. Further, the body drive control device 214 sends aperture control information to the lens drive control device 206 to control the aperture of the aperture 211.

  The lens drive controller 206 updates the lens information according to the focusing state, zooming state, aperture setting state, aperture opening F value, and the like. Specifically, the positions of the zooming lens 208 and the focusing lens 210 and the aperture value of the aperture 211 are detected, and lens information is calculated according to these lens positions and aperture values, or prepared in advance. Lens information corresponding to the lens position and aperture value is selected from the look-up table.

  The lens drive control device 206 calculates a lens drive amount based on the received defocus amount, and drives the focusing lens 210 to the in-focus position according to the lens drive amount. Further, the lens drive control device 206 drives the diaphragm 211 in accordance with the received diaphragm value.

  FIG. 2 is a diagram illustrating an example of a focus detection area (focus detection position) on a shooting screen defined on the planned imaging plane of the interchangeable lens 202. The focus detection area indicates an example of a region where an image is sampled on the shooting screen when a focus detection pixel row on the image sensor 212 described later performs focus detection. In this example, focus detection areas 101, 102, and 103 are arranged at the center and three locations on the top and bottom of the rectangular shooting screen 100. In the focus detection areas 101, 102, and 103, the focus detection pixels are linearly arranged so as to correspond to the longitudinal direction of the focus detection area indicated by a rectangle, that is, the vertical direction (vertical direction) of the photographing screen 100 in FIG. The

  FIG. 3 is a front view showing a detailed configuration of the image sensor 212, and shows an enlarged vicinity of a region on the image sensor 212 corresponding to the focus detection areas 101, 102, and 103 in FIG. The imaging pixels 310 are densely arranged in a two-dimensional square lattice pattern on the imaging device 212, and focus detection pixels 312 and 313 for focus detection are arranged in a vertical direction (positions corresponding to the focus detection areas 101, 102, and 103). The focus detection pixel columns are formed alternately and adjacently on a straight line in the vertical direction.

  The imaging pixel 310 includes the microlens 10, the photoelectric conversion unit 11 whose light receiving area is limited to a square by a light shielding mask (not shown), and a color filter (not shown). The color filters include three types of red (R), green (G), and blue (B), and have spectral sensitivity characteristics corresponding to the respective colors. In the image pickup device 212, image pickup pixels 310 having respective color filters are arranged in a Bayer array.

  The focus detection pixels 312 and 313 are provided with white filters that transmit all visible light in order to perform focus detection for all colors. The white filter has a spectral sensitivity characteristic such that the spectral sensitivity characteristics of the green pixel, the red pixel, and the blue pixel are added, and the light wavelength region exhibiting high sensitivity is each color filter in each of the green pixel, the red pixel, and the blue pixel. Includes a light wavelength region exhibiting high sensitivity.

  The focus detection pixel 312 includes a microlens 10, a photoelectric conversion unit 12 in which a light receiving region is limited to a rectangle (substantially upper half when a square is divided into two equal parts by a horizontal line) by a light shielding mask (not shown), and a white filter (not shown). (Illustrated). The focus detection pixel 313 includes a microlens 10, a photoelectric conversion unit 13 whose light receiving area is limited to a rectangle (substantially lower half when a square is divided into two equal parts by a horizontal line), and a white filter (not shown). (Illustrated). When the focus detection pixel 312 and the focus detection pixel 313 are superimposed and displayed with the microlens 10 as a reference, the photoelectric conversion units 12 and 13 in which the light receiving area is limited by the light shielding mask are arranged in the vertical direction.

  FIG. 4 shows focus detection pixels 312 and 313 that form focus detection pixel rows arranged in the image sensor 212 corresponding to the focus detection area 101 extending in the vertical direction (longitudinal direction) in the vicinity of the center of the photographing screen 100. It is sectional drawing for demonstrating the state of the focus detection light beam which light-receives.

  In FIG. 4, the optical axis 91 of the interchangeable lens, the microlenses 10a to 10d, the photoelectric conversion units 12a, 12b, 13a, and 13b, the focus detection pixels 312a, 312b, 313a, and 313b, whose light receiving areas are limited by the light shielding mask opening, Focus detection light beams 72, 73, 82 and 83 are shown.

  The photoelectric conversion units 12 and 13 of all the focus detection pixels 312 and 313 arranged on the image sensor 212 receive the light flux that has passed through the light shielding mask opening disposed in the vicinity of the photoelectric conversion units 12 and 13. The shape of the light-shielding mask opening arranged close to the photoelectric conversion unit 12 of each focus detection pixel 312 is the focus detection on the distance measurement pupil plane 90 separated from the microlens 10 by the distance measurement pupil distance d by the microlens 10. Projection is performed on a region 92 common to all of the pixels 312. Similarly, the shape of the light-shielding mask opening disposed in the vicinity of the photoelectric conversion unit 13 of each focus detection pixel 313 is a focus on the distance measurement pupil plane 90 that is separated from the microlens 10 by the distance measurement pupil distance d by the microlens 10. Projection is performed on a region 93 common to all the detection pixels 313. The pair of areas 92 and 93 is called a distance measuring pupil.

  The photoelectric conversion units 12a and 12b of the focus detection pixels 312a and 312b receive the focus detection light beams 72 and 82 that pass through the distance measuring pupil 92 and the microlenses 10a and 10c of the imaging pixels, and are received by the focus detection light beams 72 and 82. A signal corresponding to the intensity of the image formed on each microlens 10a, 10c is output. The photoelectric conversion units 13a and 13b of the focus detection pixels 313a and 313b receive focus detection light beams 73 and 83 that pass through the distance measuring pupil 93 and the microlenses 10b and 10d of the imaging pixels, and focus detection light beams 73 and 83 are received. To output a signal corresponding to the intensity of the image formed on each of the microlenses 10b and 10d.

  In FIG. 4, four focus detection pixels (pixels 312 a, 313 a, 312 b, and 313 b) adjacent to the photographing optical axis 91 are schematically illustrated, but other focus detection pixels included in the focus detection area 101 are illustrated. In addition, the photoelectric conversion units receive the light fluxes that arrive at the microlenses from the corresponding distance measurement pupils 92 and 93, respectively. The arrangement direction of the focus detection pixels coincides with the arrangement direction of the pair of distance measuring pupils, that is, the arrangement direction of the pair of photoelectric conversion units.

  FIG. 5 shows focus detection pixels 312 and 313 that form focus detection pixel rows arranged in the image sensor 212 corresponding to the focus detection area 102 extending in the vertical direction (longitudinal direction) in the peripheral region of the shooting screen 100. It is a figure for demonstrating the state of the focus detection light beam which light-receives.

  FIG. 5 shows photoelectric conversion units 12c, 12d, 13c, and 13d whose focus areas are limited by the microlenses 10e to 10h, light shielding mask openings, focus detection pixels 312c, 312d, 313c, and 313d, focus detection light beams 172 and 173, 182, 183 are shown.

  The photoelectric conversion units 12c and 12d of the focus detection pixels 312c and 312d receive the focus detection light beams 172 and 182 that pass through the distance measuring pupil 92 and the microlenses 10e and 10g of the respective imaging pixels, and are received by the focus detection light beams 172 and 182. A signal corresponding to the intensity of the image formed on each microlens 10e, 10g is output. The photoelectric conversion units 13c and 13d of the focus detection pixels 313c and 313d receive the focus detection light beams 173 and 183 that pass through the distance measuring pupil 93 and the microlenses 10f and 10h of the imaging pixels, and focus detection light beams 173 and 183. To output a signal corresponding to the intensity of the image formed on each of the microlenses 10f and 10h.

  In FIG. 5, adjacent four focus detection pixels (pixels 312 a, 313 a, 312 b, and 313 b) in the focus detection area 102 are schematically illustrated, but other focus detection pixels included in the focus detection area 102 are illustrated. In addition, the photoelectric conversion units receive the light fluxes that arrive at the microlenses from the corresponding distance measurement pupils 92 and 93, respectively.

  4 and 5, the pair of distance measuring pupils 92 and 93 are arranged symmetrically with respect to the optical axis 91. When the focus detection area is arranged around the photographing screen as shown in FIG. The light beam passing through the centers of the distance measurement pupils 92 and 93 intersects the optical axis 91 at the distance measurement distance.

  The arrangement of the focus detection pixels corresponding to the focus detection area 103 is the same as the arrangement of the focus detection pixels corresponding to the focus detection area 102, and the focus detection pixels corresponding to the focus detection area 103 are also distance-measured. A light beam passing through the pupils 92 and 93 is received.

  As described above, in the region corresponding to the focus detection areas 101 to 103, a large number of the pair of focus detection pixels 312 and 313 are arranged alternately and linearly. The output of the photoelectric conversion unit of each focus detection pixel is grouped into a pair of output groups corresponding to the distance measurement pupil 92 and the distance measurement pupil 93, so that a pair of focus detection light beams passing through the distance measurement pupil 92 and the distance measurement pupil 93, respectively. Information on the intensity distribution of a pair of images formed on the vertical focus detection pixel column. By applying an image shift detection calculation process (correlation calculation process, phase difference detection process), which will be described later, to this information, an image shift amount of a pair of images is detected by a so-called pupil division type phase difference detection method. Further, by performing a conversion calculation using a conversion coefficient corresponding to the proportional relationship between the distance between the center of gravity of the pair of distance measurement pupils and the distance measurement pupil distance to the image shift amount, the focus adjustment state (defocusing) in each focus detection area is performed. Amount) is calculated.

  FIG. 6 is a diagram illustrating a relationship between a pair of focus detection light beams that arrive at each focus detection area from a pair of distance measurement pupils. 4 and 5, the focus detection areas 101A, 102A, and 103A corresponding to the focus detection areas 101, 102, and 103A have a pair of focus detection light beams that pass through the pair of distance measurement pupils 92 and 93. An image is formed. The focus detection pixels arranged corresponding to the focus detection areas 101A, 102A, and 103A output pixel signals corresponding to the pair of images. The focus detection light beam 272 passing through the distance measurement pupil 92 and the focus detection light beam 273 passing through the distance measurement pupil 93 form a pair of images in the focus detection region 101A. The focus detection light beam 282 passing through the distance measurement pupil 92 and the focus detection light beam 283 passing through the distance measurement pupil 93 form a pair of images in the focus detection region 102A. The focus detection light beam 292 passing through the distance measurement pupil 92 and the focus detection light beam 293 passing through the distance measurement pupil 93 form a pair of images in the focus detection region 103A.

  FIG. 7 is a diagram corresponding to FIG. 6, where the exit pupil distance dn from the image sensor 212 to the exit pupil 95 of the interchangeable lens is shorter than the distance measurement pupil distance d, and the exit pupil distance df is the distance measurement pupil distance d. In a longer case, each pair of focus detection light fluxes (272, 273), (282, 283), (292, 293) arriving at the focus detection regions 101A, 102A, 103A is the aperture due to the exit pupil 95 of the interchangeable lens. It is a figure showing how it was restricted by erosion and vignetting. The exit pupil 95 of the interchangeable lens is an image when the aperture stop is viewed from the image sensor side.

  When the exit pupil 95 of the interchangeable lens is an exit pupil 95A at a distance d from the image sensor 212, the pair of distance measurement pupils 92 and 93 is limited to a circular exit pupil centered on the optical axis. Therefore, each pair of focus detection light beams (272, 273), (282, 283), (292, 293) arriving at the focus detection regions 101A, 102A, 103A is limited symmetrically with respect to the optical axis. .

  In FIG. 7, when the exit pupil 95 of the interchangeable lens is the exit pupil 95B located at the exit pupil distance dn from the image sensor 212, the pair of focus detection light beams (272, 273) arriving at the focus detection region 101A are on the optical axis. The pair of focus detection light fluxes (282, 283) and (292, 293) arriving at the focus detection regions 102A and 103A are asymmetric with respect to the optical axis. It is limited to be asymmetric by the symmetric exit pupil 95B.

  FIG. 8A is a diagram showing a pair of focus detection light beams (282, 283) arriving at the focus detection region 102A in a cross section on the surface where the exit pupil 95B is arranged. The exit pupil 95B limits the focus detection light beam 283 received by the focus detection pixel 313 more than the focus detection light beam 282 received by the focus detection pixel 312. Accordingly, when viewed in a cross section on the plane where the exit pupil 95B is disposed, the region through which the focus detection light beam 282 that is not limited by the exit pupil 95B passes is the passage of the focus detection light beam 283 that is not limited by the exit pupil 95B. It is bigger than the area to be.

  FIG. 8B is a view showing a pair of focus detection light beams (292, 293) arriving at the focus detection region 103A in a cross section on the plane where the exit pupil 95B is arranged. The exit pupil 95B limits the focus detection light beam 292 received by the focus detection pixel 312 more than the focus detection light beam 293 received by the focus detection pixel 313. Therefore, when viewed in a cross-section on the plane where the exit pupil 95B is disposed, the region through which the focus detection light beam 293 that is not limited by the exit pupil 95B passes is the passage of the focus detection light beam 292 that is not limited by the exit pupil 95B. It is bigger than the area to be.

  When the exit pupil 95 of the interchangeable lens is the exit pupil 95C located at the exit pupil distance df from the image sensor 212, the pair of focus detection light beams (272, 273) arriving at the focus detection region 101A are symmetrical with respect to the optical axis. However, each pair of focus detection light fluxes (282, 283) and (292, 293) arriving at the focus detection areas 102A and 103A are asymmetric with respect to the optical axis, and thus are symmetric with respect to the optical axis. The pupil 95C is asymmetrically limited in the opposite direction to that of FIG.

  FIG. 9A is a diagram showing a pair of focus detection light beams (282, 283) arriving at the focus detection region 102A in a cross section on the plane where the exit pupil 95C is arranged. The exit pupil 95C limits the focus detection light beam 282 received by the focus detection pixel 312 more than the focus detection light beam 283 received by the focus detection pixel 313. Accordingly, when viewed in a cross section on the plane where the exit pupil 95C is arranged, the region through which the focus detection light beam 283 that is not limited by the exit pupil 95C passes is the passage of the focus detection light beam 282 that is not limited by the exit pupil 95C. It is bigger than the area to be.

  FIG. 9B is a diagram showing a pair of focus detection light beams (292, 293) arriving at the focus detection region 103A in a cross section on the plane where the exit pupil 95C is arranged. The exit pupil 95C restricts the focus detection light beam 293 received by the focus detection pixel 313 more than the focus detection light beam 292 received by the focus detection pixel 312. Accordingly, when viewed in a cross section on the plane where the exit pupil 95C is disposed, the region through which the focus detection light beam 292 that is not restricted by the exit pupil 95C passes is the passage of the focus detection light beam 293 that is not restricted by the exit pupil 95C. It is bigger than the area to be.

  As described above, when the pair of focus detection light beams are symmetrically limited by the exit pupil 95 of the interchangeable lens, the light amounts received by the focus detection pixels 312 and 313 are the same, and the pair of focus detection light beams formed by the pair of focus detection light beams The intensity distribution corresponding to the image also has the same output level. However, when the pair of focus detection light fluxes are asymmetrically limited by the exit pupil 95 of the interchangeable lens, the amount of light received by the focus detection pixels 312 and 313 differs, so that the pair of focus detection light fluxes form a pair of images. Corresponding intensity distributions will also produce level differences.

  FIG. 10 is a flowchart showing the operation of the digital still camera 201 shown in FIG. Each processing step shown in FIG. 10 is executed by the body drive control device 214. When the power of the digital still camera 201 is turned on in step S100, the body drive control device 214 starts the operation after step S110. In step S <b> 110, the image pickup pixel data is read out and displayed on the liquid crystal display element 216. In subsequent step S120, a pair of image data corresponding to the pair of images is read from the focus detection pixel array. Note that the focus detection area is selected by the photographer using an area selection switch (not shown).

  In step S130, out of the read pair of image data, the pair incident on the focus detection area according to the position of the focus detection area and the exit pupil distance and distance measurement pupil distance of the interchangeable lens obtained by lens communication. Image data corresponding to an image formed by a focus detection light beam with a small amount of vignetting (i.e., a large amount of light) is determined as fixed data, and the other image data is used as displacement data. decide. The photographer selects an arbitrary focus detection area from among the plurality of focus detection areas 101 to 103 on the shooting screen 100 in FIG. 2 every time shooting is performed, but any focus detection area is selected. Fixed data and displacement data are determined for each selected focus detection area. The displacement data is displaced with respect to the determined fixed data, and an image shift detection calculation process (correlation calculation process) described later is performed to calculate the image shift amount and convert it into a defocus amount. As described above with reference to FIGS. 8 and 9, in the region where one of the pair of focus detection light fluxes with less vignetting (restriction) by the exit pupil passes through the exit pupil plane, the other light flux passes through the exit pupil plane. Since it is larger than the region through which it passes, the amount of light of the one light beam is larger than that of the other light beam. By using image data corresponding to an image formed by a focus detection light beam with a large amount of light as fixed data, the contrast becomes high, so that a decrease in focus detection accuracy can be prevented.

  Specifically, as shown in FIGS. 7, 8, and 9, after first classifying the cases according to the size comparison between the exit pupil distance and the distance measurement pupil distance, the position (image height) of the focus detection area is as shown in FIG. 7. The image data corresponding to the image formed by the focus detection light beam with a small amount of vignetting (restriction) by the exit pupil, that is, a large amount of light, is set as fixed data depending on whether the optical axis 91 is above or below the optical axis 91 select.

  In step S140, it is checked whether or not the focus is close, that is, whether or not the calculated absolute value of the defocus amount is within a predetermined value. If it is determined that the focus is not close, the process proceeds to step S150, the defocus amount is transmitted to the lens drive control unit 206, the focusing lens 210 of the interchangeable lens 202 is driven to the focus position, and the process returns to step S110. The above operation is repeated. Even when focus detection is impossible, the process branches to this step, a scan drive command is transmitted to the lens drive control device 206, and the focusing lens 210 of the interchangeable lens 202 is driven to scan from infinity to the nearest. Then, it returns to step S110 and repeats the operation | movement mentioned above.

  On the other hand, if it is determined in step S140 that the focus is close to the in-focus state, the process proceeds to step S160, and it is determined whether or not a shutter release has been performed by operating a shutter button (not shown). If it is determined that the shutter release has not been performed, the process returns to step S110 and the above-described operation is repeated. If the shutter has been released, the process proceeds to step S170, where an aperture adjustment command is transmitted to the lens drive control device 206, and the aperture value of the interchangeable lens 202 is controlled to an F value (an F value set by the photographer or an automatically set F value). Value).

  When the aperture control is finished, the image sensor 212 is caused to perform an imaging operation, and image data is read from the imaging pixels of the image sensor 212 and all focus detection pixels. In step S180, pixel data at each pixel position in the focus detection pixel column is generated by pixel interpolation based on pixel data of imaging pixels around the focus detection pixel. In subsequent step S190, the image data including the pixel data of the imaging pixel and the pixel data generated by the pixel interpolation is stored in the memory card 219, and the process returns to step S110 to repeat the above-described operation.

  Details of the image shift detection calculation process (correlation calculation process) in step S130 of FIG. 10 will be described. In the image shift detection calculation processing, a part of the pair of image data having a predetermined data range is cut out from one image data corresponding to the focus detection light beam having a large light amount, and the part of the data is set as fixed data. Next, the other image data is used as displacement data, and a portion having a data range of the same size as the fixed data is extracted while shifting, and the degree of correlation between the fixed data and the extracted displacement data is correlated. Calculate by calculation. Of the correlation degrees calculated in this way, the shift amount having the highest correlation degree is set as the image shift amount of the pair of image data. Fixed data cut out from one of the pair of image data is cut out so as to include high-contrast image data in order to reduce an error in correlation calculation.

  A method of selecting image data used as fixed data and image data used as displacement data from a pair of image data will be described.

  In FIG. 2, when the focus detection area 101 in the center of the photographing screen 101, that is, on the optical axis is selected, as shown in FIG. 7, the pair of focus detection light fluxes arriving at the focus detection area 101A are exchanged. Due to the exit pupil of the lens, the vignetting is symmetric regardless of the exit pupil distance. There is no level difference between the image data output from the array of focus detection pixels 312 and the image data output from the array of focus detection pixels 313, and the contrast of the pair of image data is equal. Accordingly, either one of the image data, for example, the image data output from the array of the focus detection pixels 312 is uniformly fixed data, and the other image data, for example, the image data output from the array of the focus detection pixels 313 is uniformly displaced data. And

  In FIG. 2, when focus detection areas 102 and 103 around the photographing screen 101, that is, outside the optical axis, are selected, as shown in FIG. 7, a pair of focal points that arrive at the focus detection areas 102A and 103A. The detected light beam is asymmetrically vignetted by the exit pupil of the interchangeable lens according to the exit pupil distance. There is a level difference between the image data output from the array of focus detection pixels 312 and the image data output from the array of focus detection pixels 313, and the contrast is also different. In such a case, if fixed data and displacement data are uniformly determined as in the case where the focus detection area 101 is selected, low-contrast image data due to a focus detection light beam with a lot of vignetting is used as fixed data, and correlation is performed. In some cases, the calculation error becomes large and a focus detection error occurs.

Therefore, when the focus detection areas 102 and 103 are selected, the amount of light is large and the contrast is high as shown in Tables 1 and 2, respectively, according to the position of the focus detection area and the exit pupil distance dp of the interchangeable lens. The image data is selected as fixed data, and the other image data is selected as displacement data. Table 1 shows fixed data and displacement data selected when the focus detection area 102 is selected, and Table 2 shows fixed data and displacement data selected when the focus detection area 103 is selected. Show.

  In FIG. 11, for example, the focus detection area 102 is selected, and the image data 410 (solid line) output from the array of focus detection pixels 312 and the array of focus detection pixels 313 are output when the exit pupil distance dp <d of the interchangeable lens is output. It is the figure which showed the image data 420 (dashed line) to perform. Of the image data 410 output from the array of focus detection pixels 312, a range R0 including a high contrast portion is cut out and set as fixed data. The range R0 is determined as a predetermined range including, for example, a pixel position in the image data 410 of the focus detection pixel 312 where the output differential value exhibits a maximum value. For example, the range R0 may be determined as a predetermined range including a pixel position that is searched from one end of the image data 410 output from the array of the focus detection pixels 312 and indicates an output that is equal to or greater than a threshold value. The image data 420 output from the array of focus detection pixels 313 has a lower contrast than the image data 410 output from the array of focus detection pixels 312 because the amount of received light is small, and is used as displacement data. In the image data 420 output from the array of focus detection pixels 313, a data range R1 having the same size as the fixed data is set from one data end. In addition, a data range R2 is set that is shifted from the data range R1 by one pixel of data. Further, a data range R3 is set which is shifted from the data range R2 by one pixel of data. In this way, the data range shifted by one pixel of data is set up to the other data end.

  Next, the correlation between the image data 410 output from the array of focus detection pixels 312 in the fixed data range R0 and the image data 420 output from the array of focus detection pixels 313 in the plurality of displacement data ranges R1 to Rm of the displacement data. The degree is calculated. Among the calculated correlation degrees, the image data 410 output by the array of focus detection pixels 312 and the image data 420 output by the array of focus detection pixels 313 according to the position (shift) of the displacement data range having the highest correlation degree. Is determined. A specific example of correlation calculation for calculating the degree of correlation between a pair of image data will be described below.

There are m focus detection pixels 312 and 313 in one focus detection area, the image data sequence selected as fixed data (A1 ₁ to A1 _m ), and the image data sequence selected as displacement data (A1 _l to A1 _m ). An image data string (data number r + 1) of a high contrast portion cut out from fixed data is (A1 _s to A1 _{s + r} ), and the data string and a data string in a predetermined range (data number r + 1) cut out from the displacement data The correlation amount C (k) is calculated by the correlation calculation shown in Expression (1). In this image shift detection calculation (correlation calculation), the parameter k corresponds to the shift amount (shift amount) of the data range of the displacement data with respect to the data range of the fixed data.
C (k) = Σ | A1 _n · A2 _{n + 1 + k−} A2 _{n + k} · A1 _{n + 1} | (1)

  In equation (1), variables n and n + 1 are limited to a fixed data range (s to s + r), and Σ operations are accumulated for n. The shift amount k is an integer with the data interval as a unit, and is limited to a range in which the values of n + k and n + k + 1 fall within 1 to m.

The correlation calculation formula is not limited to the formula (1), and for example, the following calculation formula (2) may be used.
C (k) = Σ | A1 _n −A2 _{n + k} | (2)

According to the calculation method disclosed in Japanese Patent Laid-Open No. 2009-141791, when it is determined that the image shift amount ks that gives the minimum value C (ks) of the correlation amount C (k) is reliable, the expression (3 ) To calculate the image shift amount shft. In equation (3), PY is a detection pitch (pitch of focus detection pixels).
shft = PY · ks (3)

As shown in Expression (4), the image shift amount calculated in Expression (3) is multiplied by a predetermined conversion coefficient kd to be converted into a defocus amount def.
def = kd · shft · Q (4)

  In equation (4), the sign coefficient Q takes a value corresponding to the selection of fixed data. For example, Q = + 1 when image data 410 output from the array of focus detection pixels 312 is selected as fixed data, and Q = −1 when image data 420 output from the array of focus detection pixels 313 is selected. . By multiplying by the code coefficient Q, defocus of the same code can be obtained regardless of the selection of fixed data.

---- Modified example ---
(1) The arrangement of the focus detection areas in the image sensor is not limited to the arrangement shown in FIG. 2, and the focus detection areas can be arranged in a horizontal direction, a vertical direction, or a diagonal direction at any position on the screen. is there. For example, when the focus detection pixels are arranged in the horizontal direction, the arrangement is such that the image sensor shown in FIG. 3 is rotated 90 degrees.

(2) For example, as shown in FIG. 12, when the focus detection area 104 is arranged at the upper right of the photographing screen 100, it is included in the focus detection pixel array arranged in the vertical direction (vertical direction) corresponding to this. The magnitude relationship of vignetting due to the exit pupil of the pair of focus detection light beams received by the pair of focus detection pixels is the focus detection above the horizontal (lateral) center line on the photographing screen 100 in the above-described embodiment. This is the same as when the area 102 is selected. The fixed data and the displacement data may be selected according to Table 1.

  That is, in the focus detection area in which the focus detection pixel rows are arranged in the vertical direction, depending on whether the position of the focus detection area is above or below the horizontal center line on the photographing screen 100, Table 1 Alternatively, fixed data and displacement data can be selected according to Table 2. Further, in the focus detection area where the focus detection pixel rows are arranged in the horizontal direction, fixed data and displacement data can be selected in the same manner as long as it is rotated 90 degrees around the center of the shooting screen. Similarly, fixed data and displacement data can be selected in a focus detection area in which focus detection pixel rows are arranged in a diagonal direction. That is, vignetting by the exit pupil of a pair of focus detection light beams received by the focus detection pixel in the focus detection area corresponding to the center of the focus detection area (focus detection light beams as shown in FIGS. 8 and 9 in the above-described embodiment). Is directly calculated from related information (ranging pupil distance d, exit pupil distance dp, microlens magnification, photoelectric converter size, etc.). Image data corresponding to a focus detection light beam with less vignetting is set as fixed data, and image data corresponding to the other focus detection light beam is set as displacement data.

(3) Instead of calculating the vignetting due to the exit pupil of the pair of focus detection light beams received by the direct focus detection pixels, the average value of the output data of the focus detection pixels is calculated for each focus detection pixel column that outputs a pair of image data. It may be calculated. Image data output from the focus detection pixel array having the larger average value is fixed data, and image data output from the focus detection pixel array having the smaller average value is displacement data. For example, in FIG. 11, the average value A1 of the image data 410 output by the array of focus detection pixels 312 is larger than the average value A2 of the image data 420 output by the array of focus detection pixels 313. Therefore, the image data 410 output from the array of focus detection pixels 312 is fixed data, and the image data 420 output from the array of focus detection pixels 313 is displacement data. As described above, if the fixed data and the displacement data are selected based on the average value of the image data, the fixed data and the displacement data can be selected by a relatively simple calculation process.

(4) In the imaging device 212 shown in FIG. 3, the focus detection pixels 312 and 313 are provided with one photoelectric conversion unit in one pixel, but a pair of photoelectric conversion units is provided in one pixel. May be. FIG. 13 shows an image sensor 212B of a modification corresponding to the image sensor 212 shown in FIG. 3, and the focus detection pixel 311 includes a pair of photoelectric conversion units in one pixel. The focus detection pixel 311 illustrated in FIG. 13 performs a function corresponding to the pair of the focus detection pixel 312 and the focus detection pixel 313 illustrated in FIG.

  The focus detection pixel 311 includes a microlens 10 and a pair of photoelectric conversion units 22 and 23. The focus detection pixel 311 is not provided with a color filter in order to increase the amount of light. The spectral sensitivity characteristic indicated by the focus detection pixel 311 is a spectral sensitivity characteristic that combines the spectral sensitivity characteristic of a photodiode that performs photoelectric conversion and the spectral sensitivity characteristic of an infrared cut filter (not shown). That is, the focus detection pixel 311 exhibits spectral sensitivity characteristics that are obtained by adding the spectral sensitivity characteristics of green pixels, red pixels, and blue pixels. The light wavelength region exhibiting high sensitivity includes the light wavelength region in which each color filter exhibits high sensitivity in each of the green pixel, red pixel, and blue pixel.

(5) In the above-described embodiment, the focus detection operation by the pupil division method using the microlens has been described. However, the present invention is not limited to such a focus detection method, and the re-imaging pupil division method is used. It can also be applied to focus detection. FIG. 14 shows a configuration example of a focus detection apparatus of a re-imaging pupil division type phase difference detection method having focus detection positions at three positions on the upper and lower sides of the photographing screen 100 shown in FIG. The focus detection operation of the re-imaging pupil division method will be described with reference to FIG. In FIG. 14, the optical axis 191 of the interchangeable lens, the condenser lenses 110 and 120, the aperture masks 111 and 121, the aperture apertures 112, 113, 122 and 123, the re-imaging lenses 114, 115, 124 and 125, and the focus detection lens. Image sensors (CCD) 116, 126 are shown.

  FIG. 14 also shows the focus detection light beams 132, 133, 142, and 143, and the exit pupil 190 that is set to the position of the distance measurement pupil distance d5 in front of the scheduled imaging surface of the interchangeable lens. Here, the distance measurement pupil distance d5 is determined according to the focal length of the condenser lenses 110 and 120, the distance between the condenser lenses 110 and 120 and the aperture openings 112, 113, 122, and 123, and the like. The distance measuring pupil 192 is an area of the aperture openings 112 and 122 projected by the condenser lenses 110 and 120. Similarly, the distance measuring pupil 193 is an area of the aperture openings 113 and 123 projected by the condenser lenses 110 and 120. Re-imaging pupil division orientation in which the condenser lens 110, aperture mask 111, aperture openings 112 and 113, re-imaging lenses 114 and 115, and image sensor 116 perform focus detection in the focus detection area 101 at the center of the imaging screen 100. A focus detection unit 207 for phase difference detection is configured.

  The condenser lens 110 is disposed in the vicinity of the planned imaging plane of the interchangeable lens. The image sensor 116 is disposed behind the condenser lens 110. A pair of re-imaging lenses 114 and 115 for re-imaging the primary image formed in the vicinity of the planned imaging plane on the image sensor 116 are disposed between the condenser lens 110 and the image sensor 116. The aperture mask 111 has a pair of aperture openings 112 and 113 disposed in the vicinity of the pair of re-imaging lenses 114 and 115 (the front surface in FIG. 14).

  The image sensor 116 is a line sensor in which a plurality of photoelectric conversion units are densely arranged along a straight line, and the arrangement direction of the photoelectric conversion units is made to coincide with the pupil division direction by the pair of distance measuring pupils 192 and 193. The pupil division direction by the pair of distance measuring pupils 192 and 193 coincides with the arrangement direction of the pair of aperture openings 112 and 113. Information corresponding to the intensity distribution of the pair of images re-imaged on the image sensor 116 is output from the image sensor 116, and the above-described image shift detection calculation processing (correlation processing, phase difference detection processing) is performed on this information. As a result, the amount of image shift between a pair of images is detected by a so-called pupil division type phase difference detection method (re-imaging method). Further, the deviation (defocus amount) of the current imaging plane with respect to the planned imaging plane is calculated by multiplying the image shift amount by a predetermined conversion coefficient.

  The image sensor 116 is projected onto the planned imaging plane by the re-imaging lenses 114 and 115, and the detection accuracy of the defocus amount (image shift amount) is determined by the detection pitch of the image shift amount. In the case of the re-imaging method, the detection pitch of the image shift amount is the arrangement pitch of the photoelectric conversion units projected on the planned imaging plane.

  The condenser lens 110 projects the aperture openings 112 and 113 of the aperture mask 111 as a pair of distance measuring pupils 192 and 193 on the exit pupil 190 positioned at the distance measuring pupil distance d5. That is, the pair of images re-imaged on the image sensor 116 is formed by the focus detection light beams 132 and 133 that pass through the pair of distance measuring pupils 192 and 193 on the exit pupil 190.

  The condenser lens 120, the diaphragm mask 121, the diaphragm apertures 122 and 123, the re-imaging lenses 124 and 125, and the image sensor 126 perform a focus detection in the focus detection area 102 on the photographing screen 100, and a re-imaging pupil division type position. A focus detection unit 207 for phase difference detection is configured.

  The condenser lens 120 is disposed in the vicinity of the planned imaging surface of the interchangeable lens. The image sensor 126 is disposed behind the condenser lens 120. A pair of re-imaging lenses 124 and 125 for re-imaging the primary image formed in the vicinity of the planned imaging plane on the image sensor 126 are disposed between the condenser lens 120 and the image sensor 126. The diaphragm mask 121 has a pair of diaphragm openings 122 and 123 disposed in the vicinity of the pair of re-imaging lenses 124 and 125 (the front surface in FIG. 14).

  The image sensor 126 is a line sensor in which a plurality of photoelectric conversion units are densely arranged along a straight line, and the arrangement direction of the photoelectric conversion units is made to coincide with the pupil division direction by the pair of distance measuring pupils 192 and 193. The pupil division direction by the pair of distance measuring pupils 192 and 193 coincides with the arrangement direction of the pair of aperture openings 122 and 123. Information corresponding to the intensity distribution of the pair of images re-imaged on the image sensor 126 is output from the image sensor 126, and the above-described image shift detection calculation processing (correlation processing, phase difference detection processing) is performed on the information. As a result, the amount of image shift between a pair of images is detected by a so-called pupil division type phase difference detection method (re-imaging method). By multiplying the image shift amount by a predetermined conversion coefficient, the deviation (defocus amount) of the current image plane with respect to the planned image plane is calculated.

  The image sensor 126 is projected onto the planned imaging plane by the re-imaging lenses 124 and 125, and the detection accuracy of the defocus amount (image shift amount) is the photoelectric that is projected onto the planned imaging plane as described above. It is determined by the arrangement pitch of the conversion units.

  The condenser lens 120 projects the aperture openings 122 and 123 of the aperture mask 121 as a pair of distance measurement pupils 192 and 193 on the exit pupil 190 located at the distance measurement pupil distance d5. That is, a pair of images re-imaged on the image sensor 126 is formed by the focus detection light beams 142 and 143 that pass through the pair of distance measuring pupils 192 and 193 on the exit pupil 190.

  Even in such a configuration, it is possible to select fixed data and displacement data according to the position of the focus detection area and the exit pupil distance of the interchangeable lens. For example, for the focus detection area 102, if the exit pupil distance dp of the interchangeable lens is shorter than the distance measuring pupil distance d5, the image data corresponding to the image formed on the image sensor 126 by the re-imaging lens 124 is set as fixed data. Image data corresponding to an image formed on the image sensor 126 by the re-imaging lens 125 is set as displacement data. If the exit pupil distance dp of the interchangeable lens is longer than the distance measuring pupil distance d5, the image data corresponding to the image formed on the image sensor 126 by the re-imaging lens 125 is set as fixed data, and the re-imaging lens 124 Image data corresponding to an image formed on the image sensor 126 is set as displacement data. Even when the exit pupil distance dp of the interchangeable lens is equal to the distance measuring pupil distance d5, the image data corresponding to the image formed on the image sensor 126 by the re-imaging lens 125 is set as fixed data, and the image is obtained by the re-imaging lens 124. Image data corresponding to an image formed on the sensor 126 can be used as displacement data.

  For the focus detection area 101, the vignetting of the pair of focus detection light beams 132 and 133 due to the exit pupil of the interchangeable lens is symmetric, so that image data corresponding to the image formed on the image sensor 116 by the re-imaging lens 114 and Any of the image data corresponding to the image formed on the image sensor 126 by the re-imaging lens 115 may be fixed data or displacement data.

(6) In the imaging device 212 shown in FIG. 3, the imaging pixel 310 is provided with a Bayer color filter, but the configuration and arrangement of the color filter are not limited to this. For example, an array of complementary color filters (green: G, yellow: Ye, magenta: Mg, cyan: Cy) may be employed.

(7) In the image sensor 212 shown in FIG. 3, the focus detection pixels 312 and 313 are not provided with color filters. However, one of the color filters of the image pickup pixel 310 (for example, a green filter) is used. The present invention can be applied even when provided.

(8) Although FIGS. 3 and 13 show examples in which the photoelectric conversion units 12, 13, 22, and 23 of the focus detection pixels 312, 313, and 311 are rectangular, the shape of the photoelectric conversion unit is limited to this. It may not be another shape. For example, the shape of the photoelectric conversion unit of the focus detection pixel may be an ellipse, a semicircle, or a polygon.

(9) In the imaging device 212 shown in FIG. 3, the example in which the imaging pixels 310 and the focus detection pixels 312 and 313 are arranged in a dense square lattice arrangement is shown, but a dense hexagonal lattice arrangement may be used.

(10) The imaging device is not limited to the digital still camera or the film still camera having the configuration in which the interchangeable lens is mounted on the camera body as described above. For example, the present invention can also be applied to a lens-integrated digital still camera, film still camera, or video camera. Furthermore, the present invention can be applied to a small camera module built in a mobile phone, a surveillance camera, a visual recognition device for a robot, and the like. The present invention can also be applied to a focus detection device other than a camera, a distance measuring device, and a stereo distance measuring device.

10 microlens, 11, 12, 13, 22, 23 photoelectric conversion unit,
72, 73, 82, 83 Focus detection luminous flux,
90 Distance pupil plane, 91 Optical axis, 92, 93 Distance pupil, 95 Exit pupil,
100 shooting screen, 101, 102, 103, 104 focus detection area,
110, 120 condenser lens,
111, 121 Aperture mask, 112, 113, 122, 123 Aperture aperture,
114, 115, 124, 125 Re-imaging lens, 116, 126 Image sensor,
132, 133, 142, 143 Focus detection light flux,
172, 173, 182, 183 Focus detection light flux,
190 Exit pupil, 191 Optical axis, 192, 193 Distance pupil,
201 digital still camera, 202 interchangeable lens, 203 camera body,
204 mount unit, 206 lens drive control device, 207 focus detection unit,
208 zooming lens, 209 lens, 210 focusing lens,
211 Aperture, 212 Image sensor, 213 Electrical contact,
214 body drive control device,
215 liquid crystal display element driving circuit, 216 liquid crystal display element, 217 eyepiece,
219 memory card,
272, 273, 282, 283, 292, 293, focus detection light flux,
310 imaging pixels, 311, 312, 313 focus detection pixels,
410, 420 Image data

Claims (13)

Through each one pair of regions of the exit pupil of the optical system, and light receiving one of the first light flux is a light flux, a second light flux big vignetting than the other is a light beam said first light flux, the second A light receiving unit that outputs a first signal corresponding to the first light flux and a second signal corresponding to the second light flux, the light amount of which is greater than the light flux;
The correlation between the first signal and the second signal is calculated by correlation calculation while displacing the second signal with respect to the first signal with the first signal as a reference, and the first and second signals are calculated. A deviation amount detecting means for detecting a deviation amount of the two signals ;
A focus detection device comprising: focus detection means for detecting a focus adjustment state of the optical system based on the shift amount. The focus detection apparatus according to claim 1,
  The focus detection apparatus, wherein the focus detection unit detects a defocus amount as a focus adjustment state of the optical system. In the focus detection apparatus according to claim 1 or 2 ,
A selection means for selecting the first signal from the previous SL first and second signals,
A plurality of focus detection areas are set on the photographing screen of the optical system,
The light receiving unit outputs the first and second signals for each of the plurality of focus detection areas,
The selection means selects the first signal from the first and second signals related to the focus detection area based on the position of the focus detection area from the center of the shooting screen. A focus detection apparatus that selects a signal . The focus detection apparatus according to claim 3 ,
The optical system is an interchangeable lens,
Said selecting means, based on the exit pupil distance and the range-finding pupil distance position and the interchangeable lens of the focus detection area, the focus detection device, characterized by selecting said first signal. In the focus detection apparatus according to claim 1 or 2,
Selecting means for selecting the first signal from the first and second signals;
The focus detection apparatus, wherein the selection unit selects a signal having a larger average output of the first and second signals as the first signal. In the focus detection apparatus according to any one of claims 1 to 5,
The shift amount detecting means detects the shift amount by displacing the second signal with respect to a partial signal having a contrast higher than a predetermined value in the first signal. Detection device. In the focus detection apparatus according to any one of claims 1 to 6,
The deviation amount detecting means obtains a correlation amount between the first and second signals while displacing the second signal with a plurality of displacement amounts with respect to the first signal, and among the plurality of displacement amounts, the correlation amount is calculated. the amount focus detection device and detects the shift amount based on the displacement amount becomes very small. The focus detection apparatus according to claim 3 or 4 ,
The light receiving unit, the focus detection apparatus characterized by being arranged to correspond to the position of the periphery of the photographing screen. In the focus detection apparatus according to any one of claims 1 to 8 ,
The light receiving unit includes a focus detection pixel,
The focus detection device, wherein the focus detection pixel includes a microlens and a plurality of photoelectric conversion units. In the focus detection apparatus according to any one of claims 1 to 9,
The light receiving unit includes a first focus detection pixel and a second focus detection pixel,
The first focus detection pixel includes a first microlens and a first photoelectric conversion unit disposed with respect to the first microlens, and receives one of the first and second light beams,
The second focus detection pixel includes a second microlens and a second photoelectric conversion unit disposed with respect to the second microlens, and receives the other of the first and second light beams. Feature focus detection device. In the focus detection apparatus according to any one of claims 1 to 9,
The light receiving unit includes a pair of re-imaging optical systems that re-images the first pair of images formed by the first and second light beams as a second pair of images, and the second pair of images. And an image sensor that outputs a pair of data corresponding to the intensity of the focus detection device. The focus detection device according to any one of claims 1 to 11 ,
A focus adjustment device comprising: a focus adjustment unit that performs focus adjustment of the optical system in accordance with the focus adjustment state detected by the focus detection unit. Imaging apparatus characterized by comprising a focusing device according to claim 1 2.

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