JP2012088436A - Focus detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine an appropriate focus detecting process in a case where a relative attitude state between an optical system and an image pickup element is deviated from a reference attitude state.SOLUTION: This focus detecting device according to the present invention includes: an imaging optical system; a sensor chip disposed with focus detecting pixels that receive a pair of light fluxes passing through a pair of regions of an exit pupil of the imaging optical system and output a pair of image data corresponding to a pair of images formed by the pair of light fluxes; focus detecting means that calculates a phase difference between a pair of image data and detects a focus adjustment state of the imaging optical system based on the calculated phase difference; and determination means that determines a detecting process of a focus adjustment state by the focus detecting means based on attitude information representing a deviation amount from the prescribed arrangement of the imaging optical system and the sensor chip.

Description

  The present invention relates to a focus detection apparatus including focus detection pixels of a pupil division type phase difference detection method.

  Patent Document 1 discloses an imaging device including an imaging element in which focus detection pixels of a pupil division type phase difference detection method are mixed in imaging pixels. In this imaging apparatus, the focus detection pixel receives a pair of focus detection light beams that pass through an exit pupil of an optical system that forms an image. A phase difference between a pair of signals output from the focus detection pixel corresponding to the pair of focus detection light beams received by the focus detection pixel is calculated. Based on the calculated phase difference, the focus adjustment state (defocus amount) of the optical system corresponding to the image formed on the image sensor is detected.

JP 2008-268403 A

  In the focus detection apparatus using the focus detection pixel of the pupil division type phase difference detection method as described above, a tilt (shift, shift) is added to the optical system or the image sensor in order to change the perspective at the time of shooting. There may be a position adjustment error or a manufacturing error of the image sensor. In such a case, if the relative posture state between the optical system and the image sensor deviates from the reference posture state, the balance of the pair of focus detection light beams is lost, resulting in a focus detection error. There was a problem.

  A focus detection apparatus according to the present invention receives a pair of light beams passing through a pair of regions of an imaging optical system and an exit pupil of the imaging optical system, and a pair of images corresponding to a pair of images formed by the pair of light beams. A sensor chip on which focus detection pixels for outputting data are arranged, a focus detection unit that calculates a phase difference between the pair of image data and detects a focus adjustment state of the imaging optical system based on the calculated phase difference; And determining means for determining a detection processing method of the focus adjustment state by the focus detection means based on attitude information representing a deviation amount from a predetermined arrangement of the image optical system and the sensor chip.

  According to the focus detection apparatus of the present invention, when the relative posture state between the optical system and the image sensor deviates from the reference posture state due to various factors as described above, an appropriate focus detection processing method Can be determined.

It is a figure which shows the structure of the digital camera of one embodiment. It is a schematic diagram which shows the basic state of the sensor chip contained in an image sensor. FIG. 6 is a layout diagram when an image sensor (sensor chip) is shifted. FIG. 6 is a layout diagram when an image sensor (sensor chip) is tilted. It is a figure which shows the focus detection position on the imaging | photography screen of an interchangeable lens. It is a front view which shows the detailed structure of an image pick-up element. It is a figure for demonstrating the mode of the imaging light beam which an imaging pixel receives. It is a figure for demonstrating the mode of the focus detection light beam which a focus detection pixel receives. It is the figure which showed the state of a pair of focus detection light beam. It is the figure which showed the state of a pair of focus detection light beam. FIG. 6 is a view of an exit pupil and a region through which a pair of focus detection light beams are overlapped and viewed from a plane perpendicular to the optical axis on the image sensor side. FIG. 6 is a view of an exit pupil and a region through which a pair of focus detection light beams are overlapped and viewed from a plane perpendicular to the optical axis on the image sensor side. FIG. 6 is a view of an exit pupil and a region through which a pair of focus detection light beams are overlapped and viewed from a plane perpendicular to the optical axis on the image sensor side. It is the figure which showed the state of a pair of focus detection light beam. It is the figure which showed the state of a pair of focus detection light beam. FIG. 6 is a view of an exit pupil and a region through which a pair of focus detection light beams are overlapped and viewed from a plane perpendicular to the optical axis on the image sensor side. FIG. 6 is a view of an exit pupil and a region through which a pair of focus detection light beams are overlapped and viewed from a plane perpendicular to the optical axis on the image sensor side. FIG. 6 is a view of an exit pupil and a region through which a pair of focus detection light beams are overlapped and viewed from a plane perpendicular to the optical axis on the image sensor side. It is a flowchart which shows the imaging operation of the digital camera of one embodiment. It is the figure which showed the example of a pair of focus detection pixel data. It is a figure in case a pair of focus detection light flux is restrict | limited asymmetrically by the exit pupil of an optical system. FIG. 6 is a layout diagram when the optical system is shifted. FIG. 6 is a layout diagram when the optical system is tilted. It is a front view which shows the detailed structure of an image pick-up element.

  As an imaging apparatus according to an embodiment, a digital camera with interchangeable lenses will be described as an example. FIG. 1 is a cross-sectional view showing a configuration of a digital camera according to an embodiment. A digital 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. The lens drive control unit 206 performs drive control for adjusting the focus of the focusing lens 210 and adjusting the aperture diameter of the aperture 211, and detecting the states of the zooming lens 208, the focusing lens 210, and the aperture 211. Further, 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 image sensor 212, image pickup pixels are two-dimensionally arranged (rows and columns), 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 through the electrical contact 213 to receive lens information and transmit 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 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 signals of the imaging pixels and focus detection pixels are sent to the body drive control device 214.

  The body drive control device 214 calculates the defocus amount based on the pixel signal (focus detection signal) from the focus detection pixel of the image sensor 212 and sends this defocus amount to the lens drive control device 206. In addition, the body drive control device 214 processes the pixel signal (imaging signal) of the imaging pixel of the imaging element 212 to generate image data, stores the image data in the memory card 219, and reads the through image read from the imaging element 212. A signal is sent to the liquid crystal display element driving circuit 215 to display a through image 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.

  The operation member 220 is a member that is manually operated by the user to adjust the posture of the image sensor 212 described later. The body drive control device 214 acquires the adjustment amount instructed by the operation member 220 and controls the posture of the image sensor 212 by driving the posture adjustment device 221 based on the adjustment amount. Posture adjustment refers to moving the image sensor 212 in parallel to a plane perpendicular to the photographic optical axis 91 and changing the angle formed by the image sensor 212 with respect to the photographic optical axis 91.

  In the camera body 203, the image sensor 212 is disposed on a shift adjustment XY stage 222 and a tilt adjustment biaxial goniostage 223 that are connected to each other. The attitude adjustment device 221 has a drive source such as a motor and drives the stage.

  FIG. 2 is a schematic diagram showing the arrangement of the sensor chip included in the image sensor 212 in the basic state, that is, the standard state of posture adjustment.

  In FIG. 2, the zooming lens 208, the lens 209, and the focusing lens 210 shown in FIG. 1 are shown as one optical system 205 as a whole. The light receiving surface 233 of the image sensor (sensor chip) 212 is perpendicular to the optical axis 91 of the optical system 205. The center 218 of the image sensor (sensor chip) 212, that is, the center of the light receiving surface 233 is an intersection of the light receiving surface 233 and the optical axis 91.

  As described above, the basic state of the image sensor (sensor chip) 212 refers to a state in which the image sensor (sensor chip) 212 is accurately arranged at a position determined by design without error, that is, a state in a predetermined arrangement. .

  FIG. 3 is a layout diagram when the image sensor (sensor chip) 212 is shifted by the attitude adjustment device 221 driving the XY stage 222. In FIG. 3, when the image sensor (sensor chip) 212A is shifted by a sensor chip shift amount ΔXY on a plane perpendicular to the optical axis 91 and moves to the image sensor (sensor chip) 212B, the image sensor (sensor) The center 218A of the chip 212A moves to the center 218B of the image sensor (sensor chip) 212B at a position separated from the optical axis 91 by the sensor chip shift amount ΔXY. In FIG. 3, when the image sensor (sensor chip) 212 </ b> A is shifted by a sensor chip shift amount −ΔXY on a plane perpendicular to the optical axis 91 and moved to the image sensor (sensor chip) 212 </ b> C, the image sensor ( The center 218A of the sensor chip 212A moves to the center 218C of the image sensor (sensor chip) 212C at a position separated from the optical axis 91 by the sensor chip shift amount −ΔXY. In FIG. 3, the sensor chip shift amount ± ΔXY is drawn slightly larger than the size of the image sensor (sensor chip) 212A. However, FIG. 3 is schematically illustrated for easy understanding. For example, the maximum value of the sensor chip shift amount ± ΔXY is about ½ of the size of the image sensor (sensor chip) 212A. It is also possible.

  FIG. 4 is a layout diagram when the image sensor (sensor chip) 212 is tilted by the attitude adjustment device 221 rotating the goniostage 223. In FIG. 4, the normal line 207 </ b> A of the light receiving surface 233 at the center 218 of the image sensor (sensor chip) 212 </ b> A has an angle of 0 degrees with the optical axis 91. The image sensor (sensor chip) 212A is tilted by a sensor chip tilt amount Δθ with a straight line included in a plane perpendicular to the optical axis 91 and passing through the center 218 of the image sensor (sensor chip) 212 as a rotation axis. As a result, the normal 207P of the light receiving surface 233 at the center 218 of the image sensor (sensor chip) 212P is inclined by an angle Δθ with respect to the optical axis 91. The imaging element (sensor chip) 212A is tilted by a sensor chip tilt amount −Δθ with a straight line included in a plane perpendicular to the optical axis 91 and passing through the center 218 of the imaging element (sensor chip) 212 as a rotation axis. As a result, the normal line 207Q of the light receiving surface 233 at the center 218 of the image sensor (sensor chip) 212Q is inclined with respect to the optical axis 91 by an angle −Δθ. Note that FIG. 4 is schematically illustrated for easy understanding of the description. For example, the maximum value of the sensor chip tilt amount ± Δθ may be about 30 degrees.

  The above-described shooting with the posture adjustment of the image sensor (sensor chip) 212 is called so-called tilt shooting, and is a shooting method used to change the perspective of the image. For example, when shooting a high-rise building, tilt-photo shooting is used to obtain an image in which two vertical lines perpendicular to the ground are parallel to each other among the outlines of the high-rise building.

  FIG. 5 is a diagram illustrating a focus detection position on the imaging screen of the interchangeable lens 202, and a region (focus detection) in which a focus detection pixel row on the image sensor 212 described later samples an image on the imaging screen when focus detection is performed. An example of an area and a focus detection position is shown. In this example, focus detection areas 101 to 109 are arranged at the center (on the optical axis) on the rectangular shooting screen 100 and at nine locations in the up / down / left / right and diagonal directions. In the focus detection areas 101 to 109, 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 shooting screen of FIG. Points 41 to 49 represent the positions of the centers of the respective focus detection areas. As shown in FIG. 5, the x-axis is positive in the horizontal direction (lateral direction) from the point 44 to the point 46 through the center point 45 of the shooting screen, and the point 48 to the point 42 passes through the center point 45 of the shooting screen. The y-axis (axis parallel to the paper surface of FIG. 1) is defined with the vertical direction (longitudinal direction) going to the positive. The points 41 to 43 are separated from the x axis by y1 in the y axis direction, the points 44 to 46 are on the x axis, and the points 47 to 49 are separated from the x axis by -y1 in the y axis direction. The points 41, 44, and 47 are separated from the y-axis by −x1 in the x-axis direction, the points 42, 45, and 48 are on the y-axis, and the points 43, 46, and 49 are from the y-axis to the x-axis direction. x1 away.

  FIG. 6 is a front view showing a detailed configuration of the image sensor 212, and shows details of a pixel arrangement in which the vicinity of the region corresponding to the focus detection areas 101 to 109 in FIG. 5 is enlarged.

  Imaging pixels and focus detection pixels are formed on a semiconductor substrate (sensor chip) included in the imaging element 212, and the imaging pixels 310 are densely arranged in a two-dimensional square lattice. The imaging pixel 310 includes a red pixel (R), a green pixel (G), and a blue pixel (B), and is arranged according to a Bayer arrangement rule. In FIG. 6, focus detection focus detection pixels 313 and 314 having the same pixel size as the imaging pixels are alternately arranged continuously on a vertical straight line in which green and blue pixels should be continuously arranged. Arranged to form a focus detection pixel column.

  The shape of the microlens of the imaging pixel 310 and the focus detection pixels 313 and 314 is a shape that is originally cut out from a circular microlens larger than the pixel size in a square shape corresponding to the pixel size.

  The imaging pixel 310 includes a rectangular microlens 10, a photoelectric conversion unit 11 whose light receiving area is limited to a square by a light shielding mask, 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 313 and 314 are provided with a white filter that transmits 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.

  As shown in FIG. 6, the focus detection pixel 313 has a rectangular microlens 10 and a light shielding mask (not shown), and the light receiving area is limited to the upper half of a square (upper half when the square is divided into two equal parts by a horizontal line). It is comprised from the photoelectric conversion part 13 and a white filter (not shown).

  Further, as shown in FIG. 6, the focus detection pixel 314 has a rectangular microlens 10 and a light shielding mask (not shown), and restricts the light receiving area to the lower half of the square (the lower half when the square is divided into two equal parts by a horizontal line). Photoelectric conversion unit 14 and a white filter (not shown).

  When the focus detection pixel 313 and the focus detection pixel 314 are superimposed on the microlens 10 and displayed, the photoelectric conversion units 13 and 14 in which the light receiving area is limited to a half of a square by a light shielding mask are arranged in the vertical direction.

  In addition, in the focus detection pixels 313 and 314, when the remaining portion obtained by halving the square is added to the above-described light receiving region limited to the half of the square, a square having the same size as the light receiving region of the imaging pixel 310 is obtained.

  FIG. 7 is a diagram for explaining the state of the imaging light flux received by the imaging pixel 310 when the imaging element 212 (sensor chip) is arranged in the basic state as shown in FIG. The cross section of the imaging pixel array is taken.

  The photoelectric conversion units 11 of all the imaging pixels arranged on the image sensor receive the light flux that has passed through the opening of the light shielding mask disposed in the vicinity of the photoelectric conversion unit 11. The shape of the light-shielding mask opening is projected by the microlens 10 of each imaging pixel onto an area 95 common to all the imaging pixels on the ranging pupil plane 90 that is separated from the microlens 10 by the ranging pupil distance d.

  Therefore, the photoelectric conversion unit 11 of each imaging pixel receives the light beam 71 passing through the region 95 and the microlens 10 of each imaging pixel, and a signal corresponding to the intensity of the image formed on each microlens 10 by the light beam 71. Is output.

  FIG. 8 shows focus detection received by the focus detection pixels 313 and 314 in the focus detection pixel row corresponding to the focus detection area 105, for example, when the image sensor 212 (sensor chip) is arranged in the basic state as shown in FIG. It is a figure for demonstrating the mode of a light beam compared with FIG. 7, Comprising: The cross section of the focus detection pixel row | line | column is taken with the straight line of the orthogonal | vertical direction.

  The photoelectric conversion units 13 and 14 of all the focus detection pixels 313 and 314 arranged on the image pickup device 212 receive the light flux that has passed through the light shielding mask opening arranged in proximity to each of the photoelectric conversion units 13 and 14. . The shape of the light-shielding mask opening arranged in the vicinity of the photoelectric conversion unit 13 is such that the focus on the distance measuring pupil plane 90 separated from the micro lens 10 by the distance pupil distance d by the micro lens 10 of each focus detection pixel 313. Projection is performed on a region 93 common to all the detection pixels 313. Similarly, the shape of the light-shielding mask opening arranged close to the photoelectric conversion unit 14 is formed on the distance measurement pupil plane 90 separated from the microlens 10 by the distance measurement pupil distance d by the microlens 10 of each focus detection pixel 314. The image is projected onto a region 94 common to all the focus detection pixels 314. The pair of regions 93 and 94 is called a distance measuring pupil.

  Therefore, the photoelectric conversion unit 13 of each focus detection pixel 313 receives the light flux 73 passing through the distance measuring pupil 93 and the microlens 10 of each focus detection pixel 313, and an image formed on each microlens 10 by the light flux 73. A signal corresponding to the intensity of the signal is output. The photoelectric conversion unit 14 of each focus detection pixel 314 receives a light beam 74 passing through the distance measuring pupil 94 and the microlens 10 of each focus detection pixel 314, and an image formed on each microlens 10 by the light beam 74. A signal corresponding to the intensity of the signal is output.

  In a region where the distance measurement pupils 93 and 94 on the distance measurement pupil plane 90 through which the light beams 73 and 74 received by the pair of focus detection pixels 313 and 314 pass is integrated, the distance measurement through which the light beam 71 received by the imaging pixel 310 passes is measured. The light beams 73 and 74 coincide with the region 95 on the pupil plane 90, and the light beams 73 and 74 have a complementary relationship with the light beam 71 on the distance measurement pupil surface 90.

  A large number of the pair of focus detection pixels 313 and 314 described above are arranged alternately and linearly, and the output of the photoelectric conversion unit of each focus detection pixel is collected into a pair of output groups corresponding to the distance measurement pupil 93 and the distance measurement pupil 94. Thus, information on the intensity distribution of the pair of images formed on the focus detection pixel array in the vertical direction by the pair of light beams passing through the distance measuring pupil 93 and the distance measuring pupil 94 can be obtained. 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 operation 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, the image shift amount and the current image plane at the focus detection position are A deviation from the image plane, that is, a defocus amount is calculated.

  FIG. 8 shows a state of a pair of focus detection light beams 73 and 74 received by the focus detection pixels belonging to one focus detection area. On the other hand, FIGS. 9 and 10 belong to nine focus detection areas arranged at different positions on the photographing screen when the image sensor 212 (sensor chip) is arranged in the basic state as shown in FIG. A state of a pair of focus detection light beams 73 and 74 received by the focus detection pixel is shown. 9 and 10, the center positions 41 to 49 of each focus detection area and a pair of focus detection pixels in the vicinity thereof are shown as representatives.

  FIG. 9 shows a state of the pair of focus detection light beams 73 and 74 when viewed from a plane perpendicular to the x-axis of the surface 97 corresponding to the photographing screen 100, and FIG. 10 shows the surface 97 corresponding to the photographing screen 100. The state of a pair of focus detection light beams 73 and 74 when viewed from a plane perpendicular to the y-axis is shown. 9 and 10, the surface 97 is perpendicular to the optical axis 91. The exit pupil 96A when the exit pupil 96 of the optical system 205 is at the same position as the distance measurement pupil distance d in the optical axis direction, the exit pupil 96B when located at a position farther than the distance measurement pupil distance d, and the distance measurement pupil distance The exit pupil 96C in a position closer to d is shown in FIGS. 9 and 10, respectively.

  The exit pupils 96 </ b> A to 96 </ b> C of the optical system 205 are images of a diaphragm aperture when the optical system 205 is viewed from the image sensor 212 side, and become a circular pupil centered on the optical axis 91, and the pupil diameter is equal to the diaphragm aperture diameter. Will change accordingly.

  11 to 13, the exit pupils 96 </ b> A to 96 </ b> C and the region through which the pair of focus detection light beams 73 and 74 pass are overlapped on the plane on which the exit pupils 96 </ b> A to 96 </ b> C are positioned, and are perpendicular to the optical axis on the image sensor 212 side. FIG. 11A to 11I show the relationship between the exit pupils 96A to 96C and the regions through which the pair of focus detection light beams 73 and 74 pass at points 41 to 49 located at the centers of the focus detection areas 101 to 109, respectively. Show. The same applies to FIGS. 12 (a) to (i) and FIGS. 13 (a) to (i). The alternate long and short dash lines shown in FIGS. 11 to 13 pass through the center of each exit pupil 96.

  9 and 10, when the exit pupil 96 of the optical system 205 is the exit pupil 96A at the same position as the distance measuring pupil distance d in the optical axis direction, as shown in FIG. The pair of focus detection light beams 73 and 74 received by .about.109 are symmetrically limited by the exit pupil 96A. In this state, since the pair of focus detection light beams 73 and 74 are balanced, the pair of focus detection pixels 313 and 314 belonging to each focus detection area outputs signals of substantially the same level.

  9 and 10, when the exit pupil 96 of the optical system 205 is the exit pupil 96B located at a position farther than the distance measuring pupil distance d in the optical axis direction, it is arranged on the x-axis as shown in FIG. The pair of focus detection light beams 73 and 74 received by the focus detection areas 104 to 106 are symmetrically limited by the exit pupil 96B. However, the pair of focus detection light beams 73 and 74 received by the focus detection areas 101 to 103 and 107 to 109 are, by the exit pupil 96B, the distance from the surface 97 to the exit pupil 96B and the size of the pupil diameter of the exit pupil 96B ( F value) and the position (x, y) of the focus detection pixels 313 and 314 with respect to the center of the photographing screen are limited asymmetrically. In such a state, since the balance between the pair of focus detection light beams 73 and 74 is lost, the pair of focus detection pixels 313 and 314 belonging to the focus detection areas 101 to 103 and 107 to 109 outputs signals having a level difference between them. Output.

  9 and 10, when the exit pupil 96 of the optical system 205 is an exit pupil 96C located at a position closer to the distance measurement pupil distance d in the optical axis direction, it is arranged on the x-axis as shown in FIG. The pair of focus detection light beams 73 and 74 received by the focus detection areas 104 to 106 are symmetrically limited by the exit pupil 96C. However, the pair of focus detection light beams 73 and 74 received by the focus detection areas 101 to 103 and 107 to 109 are, by the exit pupil 96C, the distance from the surface 97 to the exit pupil 96C and the pupil diameter of the exit pupil 96C ( F value) and the position (x, y) of the focus detection pixel with respect to the center of the shooting screen are limited asymmetrically in the opposite direction to FIG. In such a state, since the balance between the pair of focus detection light beams 73 and 74 is lost, the pair of focus detection pixels 313 and 314 belonging to the focus detection areas 101 to 103 and 107 to 109 outputs signals having a level difference between them. Output.

  When the image sensor 212 (sensor chip) is arranged in the basic state as described above, the x axis in the direction orthogonal to the direction in which the distance measuring pupils 93 and 94 are aligned (the direction in which the focus detection light beams 73 and 74 are aligned) In the focus detection areas 104 to 106 arranged above, the pair of focus detection light beams 73 and 74 are symmetrically limited regardless of the distance from the surface 97 to the exit pupil 96 of the optical system 205. On the other hand, in the focus detection areas 101 to 103 and 107 to 109 arranged away from the x-axis, when the distance from the surface 97 to the exit pupil 96 of the optical system 205 coincides with the distance measurement pupil distance d, a pair of focus points. Although the detection light beams 73 and 74 are limited to be symmetrical, if the distance from the surface 97 to the exit pupil 96 of the optical system 205 is different from the distance measuring pupil distance d, the distance from the surface 97 to the exit pupil 96 of the optical system 205 is The pair of focus detection light beams 73 and 74 are asymmetrically limited according to the distance and the position of the focus detection area.

  Next, the state of the pair of focus detection light beams 73 and 74 when the image sensor 212 (sensor chip) is displaced from the basic state by the attitude adjusting unit 221 will be considered.

  14 and 15 show nine focus detections arranged at different positions on the photographing screen when the image sensor 212 (sensor chip) is shifted and tilted with respect to the basic state as shown in FIGS. A state of the pair of focus detection light beams 73 and 74 received by the focus detection pixels 313 and 314 belonging to the areas 101 to 109 is shown. The light receiving surface 233 of the image sensor 212 (sensor chip) is first shifted to the basic state by a shift amount (Δx1, Δy1) in a plane orthogonal to the optical axis, and then tilted around the center of the light receiving surface (Δθ1, Δθ2). Has been. In FIGS. 14 and 15, the state of the pair of focus detection light beams 73 and 74 received by the focus detection pixels 313 and 314 in the vicinity of the points 41 to 49 located at the center of each focus detection area is shown as a representative example. Show.

  FIG. 14 shows a state of the pair of focus detection light beams 73 and 74 when viewed from a plane perpendicular to the x-axis of the surface 97 corresponding to the shooting screen 100, and FIG. 15 shows the state of the surface 97 corresponding to the shooting screen 100. The state of a pair of focus detection light beams 73 and 74 when viewed from a plane perpendicular to the y-axis is shown. 14 and 15, the surface 97 is perpendicular to the optical axis 91. The exit pupil 96A when the exit pupil 96 of the optical system 205 is at the same position as the distance measurement pupil distance d in the optical axis direction, the exit pupil 96B when located at a position farther than the distance measurement pupil distance d, and the distance measurement pupil distance The exit pupil 96C when located closer to d is shown in FIGS. 14 and 15, respectively.

  16 to 18, the exit pupils 96 </ b> A to 96 </ b> C and the region through which the pair of focus detection light beams 73 and 74 pass are overlapped on the plane on which the exit pupils 96 </ b> A to 96 </ b> C are positioned, and are perpendicular to the optical axis on the image sensor 212 side. It is the figure seen from the plane. 16A to 16I show the relationship between the exit pupils 96A to 96C and the regions through which the pair of focus detection light beams 73 and 74 pass at points 41 to 49 located at the centers of the focus detection areas 101 to 109, respectively. Show. The same applies to FIGS. 17 (a) to (i) and FIGS. 18 (a) to (i). 16 to 18, which are orthogonal to each other, pass through the center of each exit pupil 96.

  When the posture of the image sensor 212 is deviated from the basic state, the exit pupil 96A of the optical system 205 is located at the same position as the distance measuring pupil distance d in the optical axis direction as shown in FIGS. In this case, as shown in FIG. 16, the pair of focus detection light beams 73 and 74 received by all the focus detection areas 101 to 109 are asymmetrically limited by the exit pupil 96A. At this time, the distance from the surface 97 to the exit pupil 96A, the size of the pupil diameter of the exit pupil 96A (F value), and the amount of deviation (deviation amount) from the basic state of the orientation of the image sensor 212 are asymmetric. Will be limited. In such a state, since the balance between the pair of focus detection light beams 73 and 74 is lost, the pair of focus detection pixels 313 and 314 belonging to the focus detection areas 101 to 109 output signals having a level difference therebetween.

  As shown in FIGS. 14 and 15, when the exit pupil 96 of the optical system 205 is an exit pupil 96B located at a position farther than the distance measuring pupil distance d in the optical axis direction, as shown in FIG. A pair of focus detection light fluxes 73 and 74 received by the detection areas 101 to 109 is detected by the exit pupil 96B, the distance from the surface 97 to the exit pupil 96B, the pupil diameter size (F value) of the exit pupil 96B, and focus detection. It is limited asymmetrically according to the position (x, y) of the pixel with respect to the center of the shooting screen and the deviation (deviation) from the basic state of the posture of the image sensor 212. In such a state, since the balance between the pair of focus detection light beams 73 and 74 is lost, the pair of focus detection pixels 313 and 314 belonging to the focus detection areas 101 to 109 output signals having a level difference therebetween.

  14 and 15, when the exit pupil 96 of the optical system 205 is the exit pupil 96C located at a position closer than the distance measuring pupil distance d in the optical axis direction, as shown in FIG. A pair of focus detection light beams 73 and 74 received by .about.109 is taken by the exit pupil 96C, the distance from the surface 97 to the exit pupil 96C, the size (F value) of the exit pupil 96C, and the focus detection pixel. Depending on the position (x, y) with respect to the center of the screen and the amount of deviation (deviation amount) from the basic state of the orientation of the image sensor 212, it is limited asymmetrically. In such a state, since the balance between the pair of focus detection light beams 73 and 74 is lost, the pair of focus detection pixels 313 and 314 belonging to the focus detection areas 101 to 109 output signals having a level difference therebetween.

  When the image sensor 212 (sensor chip) is displaced from the basic state as described above, the distance from the surface 97 to the exit pupil 96 of the optical system in all the focus detection areas 101 to 109. Alternatively, the pair of focus detection light beams 73 and 74 are asymmetrically limited according to the position of the focus detection area.

  FIG. 19 is a flowchart illustrating an imaging operation of the digital camera 201 according to the embodiment. When the power of the digital camera 201 is turned on in step S100, the body drive control device 214 starts an imaging operation after step S110. In step S <b> 100, the image sensor 212 is set to an operation mode in which the body drive control device 214 repeats the imaging operation at a constant period. In this operation mode, the image sensor 212 outputs, for example, 60 frames per second.

  In step S <b> 110, the body drive control device 214 acquires the posture adjustment amount of the image sensor 212 by the operation of the operation member 220 by the user, and controls the posture adjustment device 221 based on the acquired adjustment amount to control the image sensor 212. Adjust posture.

  In step S120, all pixel data for one frame is read. In the subsequent step S130, the data thinned out from the data of the imaging pixels is displayed on the liquid crystal display element 216 in a live view.

  In step S140, an unbalance amount of the pair of focus detection light beams received by the focus detection pixels belonging to the focus detection area selected by the selection input device (not shown) is determined. For example, when the focus detection area 103 shown in FIG. 2 is selected, the coordinates (x1, y1) of the point 43 positioned at the center of the focus detection area 103 with respect to the center of the imaging screen and the body drive control device 214 control the lens drive. Based on the lens data obtained by communication with the apparatus 206 and the attitude information of the image sensor, the amount of light through which the pair of focus detection light beams 73 and 74 pass through the exit pupil 96 of the optical system 205 is determined. The lens data is the distance of the exit pupil, the size of the exit pupil, or the F value. The orientation information of the image sensor is the shift amount (Δx1, Δy1) and the tilt amount (Δθ1, Δθ2) of the image sensor 212 shown in FIGS. A pair of focus detection light beams 73 and 74 received by the pair of focus detection pixels 313 and 314 corresponding to the focus detection area 103 are as shown in FIGS. 16 (c), 17 (c) and 18 (c). This is a state limited by the exit pupil of the optical system. In FIG. 16C, FIG. 17C, and FIG. 18C, the pair of regions through which the pair of focus detection light beams 73 and 74 pass through the exit pupil 96 of the optical system 205 is asymmetrically represented as white. Represented as a pair of regions 730 and 740. In such a state, the unbalance amount between the amounts of light in which the pair of focus detection light beams 73 and 74 pass through the exit pupil 96 of the optical system 205 is shown in FIGS. 16 (c), 17 (c), and 18 (c). ) Is expressed by a ratio MAX (SA, SB) / MIN (SA, SB) between the area SA of the region 730 and the area SB of the region 730. The unbalance amount may be obtained by geometric calculation according to parameters such as the position of the focus detection area, the exit pupil distance and size, and posture information, or a table of results obtained by measuring the above parameters as variables in advance. Alternatively, it may be determined based on the table. When the unbalance amount = 1, the area of the region 730 is equal to the area of the region 740, and the pair of focus detection light beams 73 and 74 are symmetrically limited by the exit pupil 96. As the asymmetry of the restriction by the exit pupil 96 of the pair of focus detection light beams 73 and 74 becomes larger, the unbalance amount becomes larger than 1.

  In step S150, it is checked whether the unbalance amount is greater than or equal to a predetermined threshold value (for example, 4). If the unbalance amount is greater than or equal to the predetermined threshold value, a focus detection impossible display is performed by a display device (not shown) in step S160. move on. FIG. 20 is a diagram illustrating an example of a signal waveform (focus detection pixel data) output by a pair of focus detection pixel rows when the unbalance amount is large. In FIG. 20, a level difference corresponding to the unbalance amount is generated between the focus detection pixel data 111 output from one focus detection pixel column and the focus detection pixel data 112 output from the other focus detection pixel column. . In a focus detection calculation described later, it is necessary to calculate a relative shift amount Z between a pair of focus detection pixel data in which such a level difference has occurred. However, if the level difference is greater than or equal to a predetermined value, that is, the unbalance amount is greater than or equal to a predetermined threshold, it is difficult to accurately calculate the relative shift amount Z between the pair of focus detection pixel data, which is large for focus detection calculation. An error will occur. Therefore, when the unbalance amount is equal to or larger than the predetermined threshold, it is assumed that accurate focus detection cannot be expected, and the focus detection calculation process and the focus adjustment process in steps S170 to S200 are prohibited and these steps are skipped.

  On the other hand, if the unbalance amount is less than the predetermined threshold value in step S150, it is assumed that accurate focus detection can be expected, and the process proceeds to focus detection calculation processing and focus adjustment processing in steps S170 to S200. That is, in step S150, it is determined whether or not to proceed to the focus detection calculation process and the focus adjustment process in steps S170 to S200 according to the unbalance amount obtained based on the orientation information of the image sensor in step S140. .

  In step S170, a conversion coefficient Kd used in the selected focus detection area is obtained. The conversion coefficient Kd is the amount of relative phase shift between the pair of images formed by the pair of focus detection light beams 73 and 74, and the defocus amount, that is, the deviation in the optical axis direction between the focused image plane and the imaging plane. This is a constant for converting to a unit quantity, and depends on the opening angle of a pair of focus detection light beams.

  A specific method for obtaining the conversion coefficient Kd will be described with reference to FIG. FIG. 21 is a view when the pair of focus detection light beams 73 and 74 are asymmetrically limited by the exit pupil 96 of the optical system 205. The alternate long and short dashed lines a-axis and b-axis shown in FIG. 21 pass through the center of each exit pupil 96. When the distance in the b-axis direction between the center of gravity 113 of the region 730 of the focus detection light beam 73 restricted by the exit pupil 96 and the center of gravity 114 of the region 740 of the focus detection light beam 74 restricted by the exit pupil 96 is Gb, The conversion coefficient Kd is a value obtained by dividing Gb by the exit pupil distance. Here, the exit pupil distance is a distance from the surface 97 to the exit pupil 96 shown in FIG. The positions of the centroids 113 and 114 may be obtained by geometric calculation according to the above parameters, that is, the position of the focus detection area, the exit pupil distance and size, and the posture information. The measurement results may be tabulated and determined based on the table. That is, in step S170, the conversion coefficient Kd is determined according to the orientation information of the image sensor.

  In step S180, a focus detection calculation is performed based on the data of the focus detection pixels belonging to the selected focus detection area to calculate an image shift amount, and the image shift amount is determined according to the posture information of the image sensor in step S170. The defocus amount of the selected focus detection area is calculated by multiplying the conversion coefficient Kd. Details of step S180 will be described later.

  In step S190, 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 S200, the defocus amount is transmitted to the lens drive control device 206, and the focusing lens 210 of the interchangeable lens 202 is driven to the focus position. Thereafter, the process proceeds to step S210.

  If it is determined in step S190 that the focus is close to the focus, the process proceeds to step S210. In step S210, 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. On the other hand, if it is determined that the shutter release has been performed, the process proceeds to step S220, an aperture adjustment command is transmitted to the lens drive control device 206, and the aperture value of the interchangeable lens 202 is set to the control F value (set by the photographer or automatically). (F value). When the aperture control is finished, the image sensor 212 is caused to perform an image capturing operation with an exposure time corresponding to the subject brightness, and image data is read from the image capturing pixel 310 and all the focus detection pixels 313 and 314 of the image capturing element 212.

  In step S230, the data (imaging signal) of the virtual imaging pixels at the respective pixel positions of the focus detection pixel columns 101 to 109 are changed to the data of the imaging pixels around the focus detection pixel (imaging signal) and the data of the focus detection pixel ( Pixel interpolation based on the focus detection signal). For example, the pixel interpolation processing disclosed in Japanese Unexamined Patent Application Publication No. 2009-094881 is performed. In the subsequent step S240, image data composed of image data and interpolated image data is stored in the memory card 219, and the process returns to step S110 to repeat the above-described operation.

  Next, details of a general image shift detection calculation process (correlation calculation process) used in step S180 of FIG. 19 will be described.

  The pair of images detected by the focus detection pixels may be unbalanced in the amount of received light due to the pair of focus detection light beams 73 and 74 being asymmetrically limited by the exit pupil, so that the image misalignment with respect to the light quantity balance collapse. A type of correlation calculation that can maintain detection accuracy is performed.

The correlation calculation formula (1) disclosed in Japanese Patent Application Laid-Open No. 2007-333720 for a pair of data strings (A1 _{1 to} A1 _M , A2 _{1 to} A2 _M : M is the number of data) read from the focus detection pixel string Is used to calculate the correlation amount C (k).
C (k) = Σ | A1 n × A2 n + 1 + k -A2 n + k × A1 n + 1 | ··· (1)

The Σ operation is accumulated for n. The range taken by n is limited to the range in which the data of A1 _n , A1 _{n + 1} , A2 _{n + k} , A2 _{n + 1 + k} exists according to the image shift amount k. The image shift amount k is an integer and is a relative shift amount with the data interval of the data string as a unit.

According to the calculation method disclosed in Japanese Unexamined Patent Application Publication 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 equation (2 ) To calculate the image shift amount shft. In Expression (2), PY is twice the pixel pitch of the focus detection pixels (detection pitch).
shft = PY × ks (2)

The image shift amount calculated by the equation (2) is multiplied by the conversion coefficient Kd obtained in step S170 in FIG. 19 to convert it to the defocus amount def.
def = Kd × shft (3)

  As described above, in the present invention, according to the posture information (shift amount, tilt amount) of the image sensor (sensor chip) including the focus detection pixels of the pupil division type phase difference detection method that receives the pair of focus detection light beams. Then, it is determined whether or not the focus detection using the focus detection pixel of the pupil division type phase difference detection method is performed, and the value of the conversion coefficient when the image shift amount is converted into the defocus amount is changed. Therefore, focus detection can be reliably performed regardless of the posture state of the image sensor (sensor chip).

---- Modified example ---
(1) In the above embodiment, whether or not focus detection using the focus detection pixel of the pupil division type phase difference detection method is determined according to the posture information (shift amount, tilt amount) of the image sensor (sensor chip). Or, the value of the conversion coefficient when converting the image shift amount to the defocus amount was changed. However, tilt photography can be achieved by changing the relative orientation between the optical system and the image sensor, so that the orientation of the optical system is deviated from the basic state while the orientation of the image sensor is fixed. The present invention can also be applied to a digital camera that performs shooting. The basic state of the posture of the optical system refers to a state in which the optical system is accurately arranged at a position determined by design without error, that is, a state in a predetermined arrangement.

  For example, a posture adjustment device for adjusting the posture of the optical system is incorporated in the interchangeable lens 202, and control amounts (shift amount, tilt amount) for posture adjustment are transmitted from the body drive control device 214 of the camera body 203 to the lens drive control device 206. To do. By doing this, the lens drive control device 206 controls the posture adjustment device on the lens side to adjust the posture of the optical system. On the camera body side, the control amount of the posture adjustment amount (posture information), that is, from the basic state. According to the deviation amount, it is possible to determine whether focus detection is possible using the focus detection pixel of the pupil division type phase difference detection method, or to change the value of the conversion coefficient when converting the image shift amount into the defocus amount. it can.

  FIG. 22 is an arrangement diagram when the optical system 205 is shifted from the optical axis 91 in the basic state by an optical system shift amount ± ΔXY by the attitude adjusting device incorporated on the lens side. When the optical system 205 is the optical system 205A in the basic state, the optical axis 91 is the light receiving surface 233 at the center 218 of the image sensor (sensor chip) 212, that is, the center 218 of the light receiving surface 233 of the image sensor (sensor chip) 212. The optical axis 91A coincides with the normal line 207. When the optical system 205 is shifted from the optical system 205A in the basic state by the optical system shift amount ΔXY and moved to the optical system 205B, the optical axis 91 is separated from the optical axis 91A by the optical system shift amount ΔXY. Move to 91B. When the optical system 205 is shifted from the optical system 205A in the basic state by the optical system shift amount −ΔXY and moved to the optical system 205C, the optical axis 91 is separated from the optical axis 91A by the optical system shift amount −ΔXY. Move to the optical axis 91C. Note that FIG. 22 is schematically shown for ease of explanation, and the magnitude of the optical system shift amount ± ΔXY is not limited to that shown in FIG.

  FIG. 23 is an arrangement diagram in the case where the optical system 205 is tilted by the optical system tilt amount ± Δθ around the center 218 of the image sensor 212 by the attitude adjusting device incorporated on the lens side. In FIG. 23, the angle formed between the optical axis 91A and the normal line 207 of the light receiving surface 233 at the center 218 of the image sensor (sensor chip) 212 is 0 degree. As a result of the optical system 205A being tilted by the optical system tilt amount Δθ with a straight line passing through the center 218 of the image sensor (sensor chip) 212 included in a plane perpendicular to the normal line 207 as a rotation axis, the optical system 205 Moves to the optical system 205P, and the optical axis 91P and the normal line 207 form an angle Δθ. As a result of the optical system 205A being tilted by an optical system tilt amount −Δθ with a straight line passing through the center 218 of the image sensor (sensor chip) 212 included in a plane perpendicular to the normal line 207 as a rotation axis, the optical system 205 moves to the optical system 205Q, and its optical axis 91Q and normal 207 form an angle -Δθ. Note that FIG. 23 is schematically shown for ease of explanation, and the magnitude of the optical system tilt amount ± Δθ is not limited to that shown in FIG.

  The posture adjustment of the optical system may be performed manually by an operation member (not shown) provided on the lens side. In such a case, the posture adjustment amount (shift amount, tilt amount) of the optical system performed by the operation member is transmitted from the lens drive control device 206 to the body drive control device 214, so that the posture adjustment amount on the camera body side. In accordance with (posture information), it is determined whether or not focus detection using focus detection pixels of the pupil division type phase difference detection method is performed, or the value of the conversion coefficient when converting the image shift amount into the defocus amount is changed. be able to.

(2) In the above embodiment, the relative posture between the optical system and the image sensor is intentionally changed, but the present invention is not limited to this.

  For example, when the image sensor (sensor chip) is incorporated into the camera body for manufacturing / repair of the digital camera 201 or for replacement of the image sensor 212, the image sensor (sensor chip) is displaced from the normal position due to an incorporation error. The present invention can be applied when incorporated. The posture information (posture error) at the time of incorporation is measured and stored in a storage device (not shown) in the camera body. The body drive control device 214 determines whether or not focus detection is possible using the focus detection pixels of the pupil division type phase difference detection method, and determines the image shift amount according to the stored posture information (shift amount and tilt amount). The value of the conversion coefficient when converting to the focus amount can be determined.

  With such a configuration, it is possible to relax the accuracy of the assembling position when the image sensor is incorporated into the body.

(3) The present invention can also be applied to a deviation in the direction of a pair of focus detection light beams caused by, for example, a manufacturing error of the image sensor. In some cases, the positional relationship between the parallel microlenses constituting the focus detection pixels 313 and 314 and the light-shielding mask may be relatively shifted from the designed positional relationship by parallel movement due to manufacturing errors or aging degradation. In such a case, the directions of the pair of focus detection light beams are angularly deviated from the normal directions shown in FIG. 8, that is, an angle error occurs. The position deviates from the normal position. The angle error is measured and stored as posture information (tilt amount) in a storage device (not shown) in the camera body. The body drive control device 214 determines whether or not focus detection is possible using the focus detection pixel of the pupil division type phase difference detection method according to the stored posture information (tilt amount), and sets the image shift amount as the defocus amount. The value of the conversion coefficient at the time of conversion can be determined.

(4) In the partially enlarged view of the image sensor 212 shown in FIG. 6, an example in which each pixel includes a pair of focus detection pixels 313 and 314 having one photoelectric conversion unit is shown. The photoelectric conversion unit may be provided. FIG. 24 is a partial enlarged view of an image sensor 212 that replaces the image sensor 212 shown in FIG. 6. The focus detection pixel 311 includes a pair of photoelectric conversion units 13 and 14.

  The focus detection pixel 311 shown in FIG. 24 performs a function corresponding to the pair of focus detection pixels 313 and 314 shown in FIG. The focus detection pixel 311 includes a microlens 10 and a pair of photoelectric conversion units 13 and 14. The focus detection pixel 311 is provided with a white filter, and its spectral sensitivity characteristic 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). It becomes. 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.

(5) In the image sensor in the above-described embodiment, the example in which the focus detection pixel includes the white filter has been described. However, the present invention is also applied to the case where the same color filter (for example, green filter) as that of the image capture pixel is provided. be able to.

(6) All the pixels may be configured as the focus detection pixels 311, and each focus detection pixel may include a Bayer array color filter. In this way, focus detection is possible at all positions on the shooting screen, and by adding the outputs of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311, it corresponds to the output of the imaging pixel. The output can be easily calculated.

(7) In the above-described embodiment, a CCD image sensor or a CMOS image sensor can be used as the image sensor.

(8) In the imaging device according to the above-described embodiment, the example in which the imaging pixel includes the color filter with the Bayer arrangement is shown, but the configuration and arrangement of the color filter are not limited to this. For example, the present invention can be applied to an arrangement other than the arrangement of complementary color filters (green: G, yellow: Ye, magenta: Mg, cyan: Cy) or a Bayer arrangement. Further, the present invention can also be applied to a monochrome image sensor that does not include a color filter.

(9) The imaging apparatus is not limited to the digital camera having the configuration in which the interchangeable lens is mounted on the camera body as described above. For example, the present invention can be applied to a lens-integrated digital 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, an in-vehicle camera, and the like.

10 microlens, 11, 13, 14 photoelectric conversion unit,
41 to 49 points, 71 luminous flux, 73, 74 focus detection luminous flux,
90 Distance pupil plane, 91 Optical axis, 93, 94 Distance pupil,
95 areas, 96 exit pupils, 97 planes,
100 shooting screen, 101-109 focus detection area,
111, 112 focus detection pixel data, 113, 114 center of gravity,
201 digital camera, 202 interchangeable lens, 203 camera body,
204 mount unit, 205 optical system, 206 lens drive control device, 207 normal line,
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,
218 center, 219 memory card, 220 operation member,
221 posture adjustment device, 222 XY stage, 223 gonio stage,
233 light receiving surface,
310 imaging pixels, 311, 313, 314 focus detection pixels,
730, 740 pair of regions

Claims (13)

An imaging optical system;
A sensor chip in which focus detection pixels that receive a pair of light beams passing through a pair of regions of the exit pupil of the imaging optical system and output a pair of image data corresponding to a pair of images formed by the pair of light beams are arranged. When,
A focus detection unit that calculates a phase difference between the pair of image data and detects a focus adjustment state of the imaging optical system based on the calculated phase difference;
And determining means for determining a detection processing method of the focus adjustment state by the focus detection means based on attitude information representing a deviation amount from a predetermined arrangement of the imaging optical system and the sensor chip. Focus detection device. The focus detection apparatus according to claim 1,
Posture changing means for changing a relative posture between the imaging optical system and the sensor chip;
Obtaining means for obtaining the posture information representing the deviation amount when the relative posture is changed by the posture changing means;
The focus detection apparatus, wherein the determination unit determines the detection processing method based on the posture information acquired by the acquisition unit. The focus detection apparatus according to claim 2,
The focus detection device, wherein the attitude changing unit changes the relative attitude by changing an attitude of the imaging optical system with respect to the sensor chip. The focus detection apparatus according to claim 2,
The focus detection device according to claim 1, wherein the posture changing means changes the relative posture by changing a posture of the sensor chip with respect to the imaging optical system. The focus detection apparatus according to claim 1,
A storage means for storing the posture information;
The posture information represents a posture adjustment error of the sensor chip with respect to the imaging optical system,
The focus detection apparatus, wherein the determination unit determines the detection processing method based on the posture information stored by the storage unit. In the focus detection apparatus according to any one of claims 1 to 5,
The focus detection apparatus according to claim 1, wherein the posture information is information regarding an angular deviation between an optical axis of the imaging optical system and a normal line of a light receiving surface of the sensor chip. In the focus detection apparatus according to any one of claims 1 to 5,
The focus detection apparatus according to claim 1, wherein the posture information is information related to a positional deviation between an optical axis of the imaging optical system and a design center of the sensor chip. The focus detection apparatus according to claim 1,
A storage means for storing the posture information;
The posture information represents a manufacturing error related to the position of the focus detection pixel on the sensor chip with respect to the imaging optical system,
The focus detection apparatus, wherein the determination unit determines the focus detection processing method based on the posture information stored in the storage unit. The focus detection apparatus according to claim 8, wherein
The focus detection apparatus according to claim 1, wherein the posture information is information related to a deviation of the incident direction with respect to a design value of the incident direction of the pair of light beams. In the focus detection apparatus according to any one of claims 1 to 9,
The focus detection apparatus according to claim 1, wherein the determination unit determines to convert the phase difference into a defocus amount based on a conversion coefficient corresponding to the posture information as the detection processing method. In the focus detection apparatus according to any one of claims 1 to 9,
The determining means detects, as the detection processing method, an unbalance amount of the light amount between the pair of light beams according to the posture information, and the focus detection when the unbalance amount is a predetermined value or more. A focus detection apparatus that determines to prohibit detection of the focus adjustment state by means. In the focus detection apparatus according to any one of claims 1 to 11,
The focus detection device, wherein the imaging pixels and the focus detection pixels are mixedly arranged on the sensor chip in a two-dimensional manner. In the focus detection apparatus according to any one of claims 1 to 12,
The focus detection pixel includes a microlens and a photoelectric conversion element that receives the pair of light beams through the microlens,
The focus detection apparatus, wherein the light receiving area where the photoelectric conversion element receives the pair of light beams and the pair of areas are in a conjugate relation by the microlens lens.

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