JP2017216578A - Image pickup device and electronic camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup device capable of focus detection even in marked defocusing.SOLUTION: The image pickup device comprises: a first focus detection pixel on which light from an imaging optical system is incident through a first opening provided at a first position of a light shielding film; a second focus detection pixel on which the light from the imaging optical system is incident through a second opening provided at a second position different from the first position of the light shielding film; and a pixel part which is provided with a first region in which the first focus detection pixel is disposed and a second region in which an image height is higher than in the first area and the first focus detection pixel and the second focus detection pixel are disposed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image sensor and an electronic camera.

  2. Description of the Related Art Conventionally, there has been known an image pickup device in which focus detection pixels for performing pupil division type focus detection are provided on an image pickup surface. Conventionally, there has been a problem that it is difficult to detect the focus when the focus is greatly deviated (at the time of large defocus).

JP 2005-106994 A

According to the first aspect, the imaging element includes a first focus detection pixel into which light from the photographing optical system is incident through a first opening provided at a first position of the light shielding film, and the photographing optical system. From which the light from the second focus detection pixel is incident through the second opening provided at the second position different from the first position of the light shielding film, and the first focus detection pixel is disposed. And a pixel portion provided with one region and a second region having an image height higher than that of the first region and in which the first focus detection pixel and the second focus detection pixel are arranged.
According to the second aspect, the imaging device includes a pixel unit in which a plurality of imaging pixels on which incident light is incident and a plurality of types of focus detection pixels are arranged, and the pixel unit includes a predetermined type of the pixel A first region in which focus detection pixels are arranged, and a second region in which the image height is higher than the first region and more types of focus detection pixels than the predetermined type are arranged in the first region. Have.
According to the third aspect, the electronic camera is output from the first focus detection pixel when the imaging element according to the first or second aspect and the exit pupil of the photographing optical system are at the first exit pupil position. Focus detection is performed based on the focus detection signal, and when the exit pupil of the imaging optical system is at the second exit pupil position, focus detection is performed based on the focus detection signal output from the second focus detection pixel. A section.

It is sectional drawing which shows typically the structure of the camera system which concerns on the 1st Embodiment of this invention. 2 is a plan view schematically showing an imaging surface 20 of an imaging element 210. FIG. It is explanatory drawing of the imaging and focus detection pixel. It is explanatory drawing of 1st focus detection pixel 302NR, NL. It is explanatory drawing of 2nd focus detection pixel 302SR, SL. It is explanatory drawing of 3rd focus detection pixel 302LR, LL. 2 is a plan view schematically showing an imaging surface 20 of an imaging element 210. FIG. It is the figure which expanded a part in the 1st field 60a. It is the figure which expanded a part in 2nd area | region 60b. It is the figure which expanded a part in 3rd area | region 60c. It is a flowchart of the control processing which body CPU220 performs. 12 is a flowchart of AF processing called from step S30 in FIG. 12 is a flowchart of AF processing called from step S30 in FIG. It is a perspective view which shows typically the structure of the image pick-up element 210a. 3 is a cross-sectional view schematically showing an imaging / focus detection pixel 301 and a focus detection pixel 302. FIG. It is the top view to which a part in 1st field 60a of image sensor 210a was expanded. It is the top view to which a part in 2nd field 60b of image sensor 210a was expanded. It is the top view to which a part in 3rd field 60c of image sensor 210a was expanded. It is sectional drawing which showed typically the light beam from the light spot P on the image surface S of a synthetic | combination object, and the image pick-up element 210a. It is explanatory drawing of the 1st focus detection pixel which concerns on a modification. It is explanatory drawing of the imaging surface which concerns on a modification. It is explanatory drawing of the imaging and focus detection pixel which concerns on a modification.

(First embodiment)
FIG. 1 is a cross-sectional view schematically showing the configuration of the camera system according to the first embodiment of the present invention. In FIG. 1, the components particularly related to the present invention are mainly illustrated, and the other components constituting the camera system 1 are not illustrated. The following description will focus on each part that is particularly relevant to the present invention, and description of the other parts will be omitted.

  The camera system 1 is a so-called single-lens reflex digital camera. The camera system 1 includes an interchangeable lens 100 and a camera body 200. The user can select any one of a plurality of types of interchangeable lenses 100 that are compatible with the camera body 200 (that can be attached to the camera body 200), attach the camera to the camera body 200, and perform shooting. FIG. 1 illustrates one of a plurality of types of interchangeable lenses 100.

  The camera body 200 and the interchangeable lens 100 have, for example, a bayonet type lens mount mechanism. The interchangeable lens 100 is attached to the camera body 200 by fitting the mount portion of the interchangeable lens 100 into the mount portion of the camera body 200.

  The interchangeable lens 100 includes an imaging optical system 110, a lens CPU 120, and a diaphragm 130. The imaging optical system 110 includes a lens 111 and a focusing lens 112. The imaging optical system 110 forms a subject image on an imaging surface of an imaging element 210 described later. The exit pupil position of the imaging optical system 110 varies depending on the type of the interchangeable lens 100.

  The camera body 200 includes an image sensor 210, a body CPU 220, a focus adjustment unit 230, a ROM 240, and a display device 250. The image sensor 210 is an image sensor such as a CCD or CMOS. The imaging element 210 receives the subject light that has passed through the imaging optical system 110 and outputs an imaging signal and a focus detection signal. The body CPU 220 includes a microprocessor (not shown) and its peripheral circuits. The body CPU 220 reads and executes a control program stored in advance in a ROM 240 that is a non-volatile storage medium, thereby performing control of each part of the camera body 200 and data communication with the interchangeable lens 100. The focus adjustment unit 230 includes an actuator (not shown), and adjusts the focus of the imaging optical system 110 by driving the focusing lens 112 in the optical axis direction based on the control of the body CPU 220. The display device 250 is a display device such as a liquid crystal display, for example, and displays a live view image, various setting screens, and the like.

  The body CPU 220 includes a first focus detection unit 221 and a second focus detection unit 222 in a software form. Each of these units is realized by software when the body CPU 220 executes a predetermined control program stored in the ROM 240.

  The first focus detection unit 221 detects the focus adjustment state of the imaging optical system 110 based on a focus detection signal output from an imaging / focus detection pixel described later. The second focus detection unit 222 detects the focus adjustment state of the imaging optical system 110 based on a focus detection signal output from a focus detection pixel described later.

(Description of the image sensor 210)
FIG. 2A is a plan view schematically showing the imaging surface 20 of the imaging element 210. In FIG. 2A, for convenience of explanation, the direction parallel to the upper and lower sides of the imaging surface 20 (the horizontal direction on the paper surface) is the X axis, and the direction parallel to the left and right sides of the imaging surface 20 (the vertical direction on the paper surface). A coordinate system is set with the Y axis and the front-back direction of the imaging surface 20, that is, the optical axis direction of the imaging optical system 110 as the Z axis. The same coordinate system is set for subsequent drawings.

  In FIG. 2A, a vertical line OX that is superimposed on the imaging surface 20 and bisects the imaging surface 20 in the left-right direction (X-axis direction) and the imaging surface 20 in two directions in the vertical direction (Y-axis direction) An equally divided horizontal line OY is shown. The intersection of the vertical line OX and the horizontal line OY substantially coincides with the optical axis of the imaging optical system 110. FIG. 2B is a schematic diagram in which the region 20a in the vicinity of the center of the imaging surface 20 (near the intersection of the vertical line OX and the horizontal line OY) is enlarged in the entire imaging surface 20 illustrated in FIG. 2A. .

  As shown in FIG. 2B, a large number of pixels 30 are two-dimensionally arranged in a square on the imaging surface 20. The pixel 30 includes two types of pixels: an imaging and focus detection pixel 301 used for both imaging and focus detection, and a focus detection pixel 302 used only for focus detection. FIG. ) Shows the two without any particular distinction. Hereinafter, the imaging / focus detection pixel 301 will be described by paying particular attention to the imaging / focus detection pixel 301a located at the center of the imaging surface 20 (intersection of the vertical line OX and the horizontal line OY).

  3A is an enlarged plan view of the imaging / focus detection pixel 301a located at the center of the imaging surface 20 (intersection of the vertical line OX and the horizontal line OY) among the pixels 30 illustrated in FIG. 2B. FIG. 3B is a cross-sectional view of the imaging / focus detection pixel 301a. The imaging / focus detection pixel 301a includes a microlens 31, a color filter 32, and a pair of photoelectric conversion units 34L and 34R. The pair of photoelectric conversion units 34L and 34R has a substantially semicircular shape obtained by dividing a circle along the Y-axis direction. That is, the pair of photoelectric conversion units 34L and 34R are arranged along the X-axis direction (focus detection direction). The width of the pair of photoelectric conversion units 34L and 34R in the X-axis direction is W1 at the maximum.

  The microlens 31 condenses incident light on the imaging / focus detection pixel 301a on a pair of photoelectric conversion units 34L and 34R. The incident light enters the pair of photoelectric conversion units 34L and 34R via the color filter 32. The color filter 32 is formed so that each pixel transmits red, blue, or green light and does not transmit other light. The color filter 32 of the imaging / focus detection pixel 301a is configured to form a so-called Bayer array. A wiring layer 33 is provided between the color filter 32 and the pair of photoelectric conversion units 34L and 34R. The wiring layer 33 is arranged in a portion between pixels so as not to block incident light to the pair of photoelectric conversion units 34L and 34R.

  A broken line 41 illustrated in FIG. 3B represents the optical axis of the microlens 31 (hereinafter referred to as the optical axis 41). 3B represents the center of the division position between the photoelectric conversion unit 34L and the photoelectric conversion unit 34R (hereinafter referred to as the division line 42). The photoelectric conversion unit 34L and the photoelectric conversion unit 34R have a symmetrical shape with respect to the dividing line 42 and are arranged symmetrically with respect to the dividing line 42.

  The pair of photoelectric conversion units 34L and 34R is, for example, a photodiode or the like, and outputs a photoelectric conversion signal obtained by photoelectrically converting incident light. The imaging / focus detection pixel 301a individually outputs the photoelectric conversion signal output by the photoelectric conversion unit 34L and the photoelectric conversion signal output by the photoelectric conversion unit 34R. A signal obtained by adding the pair of photoelectric conversion signals is substantially the same as an imaging signal output by a single photoelectric conversion unit that substantially matches the outer shape of the pair of photoelectric conversion units 34L and 34R. That is, the imaging / focus detection pixel 301a can output an imaging signal.

  On the other hand, the photoelectric conversion signal output by the photoelectric conversion unit 34L and the photoelectric conversion signal output by the photoelectric conversion unit 34R correspond to a pair of light beams that have passed through a pair of regions of the exit pupil of the imaging optical system 110. Therefore, a signal composed of photoelectric conversion signals output from the photoelectric conversion units 34R of a large number of imaging and focus detection pixels 301a arranged in a line along the X-axis direction (a predetermined focus detection direction, also referred to as the first direction). And a phase difference between the photoelectric conversion signals output from the photoelectric conversion unit 34L of the large number of imaging / focus detection pixels 301a, thereby detecting a focus evaluation value (defocus amount) of the imaging optical system 110. Can be calculated. That is, the imaging and focus detection pixel 301a can also output a focus detection signal capable of performing a known phase difference focus detection calculation.

  As described above, the pair of photoelectric conversion units 34 </ b> L and 34 </ b> R included in the imaging / focus detection pixel 301 a outputs a photoelectric conversion signal that is used as both an imaging signal and a pupil-division focus detection signal. Note that the step of adding a pair of photoelectric conversion signals to obtain an image pickup signal and the step of using the pair of photoelectric conversion signals as a focus detection signal may be executed by the image pickup and focus detection pixel 301a or in the image pickup element 210. May be executed by a dedicated circuit provided in the image sensor 210, may be executed by a dedicated circuit provided outside the imaging device 210, or may be executed by the body CPU 220.

  Next, a description will be given focusing on another imaging and focus detection pixel 301b (see FIG. 2B) that is separated by 4 pixels in the right direction (+ X direction) of the drawing with respect to the imaging and focus detection pixel 301a. FIG. 3C is a cross-sectional view of the imaging / focus detection pixel 301b. Similarly to the imaging and focus detection pixel 301a, the imaging and focus detection pixel 301b includes a microlens 31, a color filter 32, and a pair of photoelectric conversion units 34L and 34R. However, as is apparent from a comparison between FIG. 3B and FIG. 3C, the imaging / focus detection pixel 301a includes the position of the optical axis 41 of the microlens 31 and the pair of photoelectric conversion units 34L and 34R. Whereas the position of the dividing line 42 representing the center of the dividing position is substantially the same in the X-axis direction, the imaging / focus detection pixel 301b is configured such that the optical axis 41 and the dividing line 42 are separated by a distance 40 in the X-axis direction. Yes.

  Thus, in the imaging / focus detection pixel 301b located away from the center of the imaging surface 20, the position of the optical axis 41 of the microlens 31 and the dividing line 42 of the pair of photoelectric conversion units 34L and 34R are separated. The distance 40 increases as the distance from the center of the imaging surface 20 increases. The light beam that has passed through the imaging optical system 110 is incident on the imaging and focus detection pixel 301b from the upper left side of the drawing in FIG. 3C toward the lower right side of the drawing. The lens 31 is arranged so as to be shifted by a distance 40 corresponding to the angle of incident light. 3B and 3C, only the shift in the X-axis direction has been described. Similarly, in the Y-axis direction, the position of the microlens 31 and the positions of the pair of photoelectric conversion units 34L and 34R are different. Are arranged as follows.

  Next, the focus detection pixel 302 will be described. In addition to the imaging and focus detection pixels described above, the image sensor 210 includes first focus detection pixels 302NL and 302NR, second focus detection pixels 302SL and 302SR, third focus detection pixels 302LL and 302LR, a fourth focus detection pixel 302SNL, There are many types of focus detection pixels 302SNR and fifth focus detection pixels 302LNL and 302LNR. The locations where these focus detection pixels are arranged will be described in detail later. First, the structure of these focus detection pixels will be described first.

  FIG. 4A is a cross-sectional view of the first focus detection pixel 302NR. The first focus detection pixel 302NR includes a microlens 31, a photoelectric conversion unit 34, and a light shielding member 35. The difference between the imaging / focus detection pixel 301b and the first focus detection pixel 302NR is that the color filter 32 is not provided, and one photoelectric conversion that is not divided is used instead of the pair of photoelectric conversion units 34L and 34R. It has the part 34 and has the light-shielding member 35.

  The light shielding member 35 is a thin film (light shielding film) that shields incident light. An opening 36NR is provided at a predetermined position (referred to as a first position) of the light shielding member 35. Only the light beam that has passed through the opening 36NR enters the photoelectric conversion unit 34, and the other light beams are shielded by the light shielding member 35 and do not enter the photoelectric conversion unit 34. The width of the opening 36NR in the X-axis direction (focus detection direction) is W2, which is smaller than the width W1 in the X-axis direction of the photoelectric conversion unit 34L and the photoelectric conversion unit 34R illustrated in FIG.

  FIG. 4B is a cross-sectional view of the first focus detection pixel 302NL. The first focus detection pixel 302NL has substantially the same configuration as the first focus detection pixel 302NR, and the first focus detection pixel 302NR is provided with an opening 36NL instead of the opening 36NR in the light shielding member 35. It is a difference. The opening 36NL has the same size and the same shape as the opening 36NR, but the position on the light shielding member 35 is different from the opening 36NR.

  The openings 36NR and 36NL are located on the left and right sides of the alternate long and short dash line 44N. That is, the alternate long and short dash line 44N is a straight line that defines the division center of the openings 36NR and 36NL. In the following description, the alternate long and short dash line 44N is referred to as a dividing line 44N. The first focus detection pixel 302NR outputs a light reception signal corresponding to the light image of the subject formed on the right side of the dividing line 44N, and the first focus detection pixel 302NL outputs the light of the subject formed on the left side of the dividing line 44N. A light reception signal corresponding to the image is output. In other words, the first focus detection pixels 302NR and 302NL receive a pair of pupil-divided light beams and output a pair of focus detection signals.

  The widths of the openings 36NR and 36NL in the focus detection direction (X-axis direction) are smaller than the widths in the focus detection direction (X-axis direction) of the photoelectric conversion units 34R and 34L described with reference to FIGS. . In other words, the light flux limited by the photoelectric conversion units 34R and 34L of the imaging / focus detection pixel 301 is incident on the photoelectric conversion units 34 of the first focus detection pixels 302NR and 302NL. Therefore, particularly when the defocus amount is large, that is, when the focus is greatly deviated from the subject portion to be focused, the focus detection signals output from the first focus detection pixels 302NR and 302NL are the imaging and focus detection pixels. Compared with the focus detection signal output from 301, the contrast becomes stronger. Therefore, even if it is difficult to detect the phase difference in the focus detection signal output from the imaging and focus detection pixel 301, the phase difference is detected by the focus detection signal output from the first focus detection pixels 302NR and 302NL. Can be done.

  In the following description, the width of the openings 36NR and 36NL in the focus detection direction is smaller than the width of the photoelectric conversion units 34R and 34L in the focus detection direction (X-axis direction). The width in the focus detection direction (X-axis direction) may be smaller than the width of the photoelectric conversion units 34R and 34L in the focus detection direction (X-axis direction) ". That is, the “width in the focus detection direction (X-axis direction) of the photoelectric conversion unit 34” indicates not the actual width of the photoelectric conversion unit 34 but the width of the incident range of incident light with respect to the photoelectric conversion unit 34. "The width of the photoelectric conversion unit 34 in the focus detection direction (X-axis direction) is smaller than the width of the photoelectric conversion units 34R and 34L in the focus detection direction (X-axis direction)" means that the photoelectric conversion unit 34 is actually used. It includes the case where the light shielding member 35 is formed so as to have a small width, and the case where the light shielding member 35 is provided so that the incident range of light incident on the photoelectric conversion unit 34 is small.

  The dividing line 44N substantially coincides with the dividing line 42 that bisects the photoelectric conversion unit 34 in the left-right direction (X-axis direction). 4A and 4B show a principal ray 43N passing through the apex of the microlens 31 among the principal rays of the exit pupil of the imaging optical system 110. FIG. The principal ray 43N forms an angle θN with respect to the optical axis 41 of the microlens 31. The position of the dividing line 44N corresponds to the position of the principal ray 43N assumed by the first focus detection pixels 302NR and 302NL.

  FIG. 5A is a cross-sectional view of the second focus detection pixel 302SR, and FIG. 5B is a cross-sectional view of the second focus detection pixel 302SL. The second focus detection pixels 302SR and 302SL have substantially the same configuration as the first focus detection pixels 302NR and 302NL shown in FIGS. 4A and 4B, respectively. The difference from the first focus detection pixels 302NR and 302NL is that openings 36SR and 36SL are provided instead of 36NL.

  The openings 36SR and 36SL have substantially the same size and the same shape as the openings 36NR and 36NL, respectively. The openings 36SR and 36SL are located on the left and right sides of the two-dot chain line 44S. That is, the two-dot chain line 44S is a straight line that defines the division center of the openings 36SR and 36SL. In the following description, the two-dot chain line 44S is referred to as a dividing line 44S.

  The dividing line 44S is located on the right side relative to the dividing line 44N shown in FIGS. 4 (a) and 4 (b). Accordingly, the dividing line 44S is present at a position that is a predetermined distance in the right direction from the dividing line 42 that bisects the photoelectric conversion unit 34 in the left-right direction (X axis direction).

  FIGS. 5A and 5B show a principal ray 43S passing through the top of the microlens 31 among the principal rays of the exit pupil of the imaging optical system 110. FIG. The principal ray 43S forms an angle θS with respect to the optical axis 41 of the microlens 31. The angle θS is larger than the angle θN illustrated in FIGS. 4 (a) and 4 (b). That is, even when the exit pupil of the imaging optical system 110 is relatively close and no subject light is incident on the openings 36NR and 36NL of the first focus detection pixels 302NR and 302NL, the openings 36SR and 36SL. Subject light is incident on. The position of the dividing line 44S corresponds to the position of the principal ray 43S assumed by the second focus detection pixels 302SR and 302SL. As described above, the opening 36NR is disposed at the first position, whereas the opening 36SR is disposed at the second position different from the first position.

  FIG. 6A is a cross-sectional view of the third focus detection pixel 302LR, and FIG. 6B is a cross-sectional view of the third focus detection pixel 302LL. The third focus detection pixels 302LR and 302LL have substantially the same configuration as the first focus detection pixels 302NR and 302NL shown in FIGS. 4A and 4B, respectively. The difference from the first focus detection pixels 302NR and 302NL is that openings 36LR and 36LL are provided instead of 36NL.

  The openings 36LR and 36LL have substantially the same size and the same shape as the openings 36NR and 36NL, respectively. The openings 36LR and 36LL are located on the left and right sides of the two-dot chain line 44L. That is, the two-dot chain line 44L is a straight line that defines the division center of the openings 36LR and 36LL. In the following description, the two-dot chain line 44L is referred to as a dividing line 44L.

  The dividing line 44L is located on the left side relative to the dividing line 44N shown in FIGS. 4 (a) and 4 (b). Therefore, the dividing line 44L exists at a position away from the dividing line 42 that bisects the photoelectric conversion unit 34 in the left-right direction (X-axis direction) in the drawing by a predetermined distance in the left direction.

  FIGS. 6A and 6B show a principal ray 43S passing through the apex of the microlens 31 among the principal rays of the exit pupil of the imaging optical system 110. FIG. The principal ray 43L forms an angle θL with respect to the optical axis 41 of the microlens 31. The angle θL is smaller than the angle θN illustrated in FIGS. 4 (a) and 4 (b). That is, even when the exit pupil of the imaging optical system 110 is at a relatively distant position and no subject light is incident on the openings 36NR and 36NL of the first focus detection pixels 302NR and 302NL, the openings 36LR and 36LL. Subject light is incident on. The position of the dividing line 44L corresponds to the position of the principal ray 43L assumed by the third focus detection pixels 302LR and 302LL.

  The focus detection pixels further include fourth focus detection pixels 302SNL and 302SNR (both not shown) and fifth focus detection pixels 302LNL and 302LNR (both not shown). The fourth focus detection pixels 302SNL and 302SNR correspond to the first focus detection pixels 302NL and 302NR, respectively, and the division center of the opening provided in the light shielding member 35 is the division line 44N in the first focus detection pixels 302NL and 302NR. And between the third focus detection pixels 302LL and 302LR and the dividing line 44L. That is, the exit pupil of the imaging optical system 110 is farther than the position assumed by the first focus detection pixels 302NL and 302NR and closer to the position assumed by the third focus detection pixels 302LL and 302LR. In some cases, the focus detection signal can be suitably output. The fifth focus detection pixels 302LNL and 302LNR correspond to the first focus detection pixels 302NL and 302NR, respectively, and the division center of the opening provided in the light shielding member 35 is the dividing line 44N in the first focus detection pixels 302NL and 302NR. , Between the second focus detection pixels 302SL and 302SR and the dividing line 44S. That is, the exit pupil of the imaging optical system 110 is closer to the position assumed by the first focus detection pixels 302NL and 302NR and farther than the position assumed by the second focus detection pixels 302SL and 302SR. In some cases, the focus detection signal can be suitably output.

  As described above, the image sensor 210 includes five types of focus detection pixels (first focus detection pixels 302NL and 302NR, second focus detection pixels 302SL and 302SR, third focus detection pixels 302LL and 302LR, and fourth focus detection pixels 302SNL. , 302SNR, fifth focus detection pixels 302LNL, 302LNR), and these five types of focus detection pixels have different assumed exit pupil positions. That is, each corresponds to a different imaging optical system 110. The position of the exit pupil changes, for example, when the interchangeable lens 100 is replaced with a different type or when the zoom position is changed in a so-called zoom lens with a variable focal length. If so, a focus detection signal can be reliably obtained from any focus detection pixel regardless of the position of the exit pupil.

  Next, the arrangement of the various types of focus detection pixels described above will be described. FIG. 7 is a plan view schematically showing the imaging surface 20 (that is, the imaging screen) of the imaging element 210. Now, consider five regions in which the imaging surface 20 is equally divided in the left-right direction. Each region has a rectangular outer shape whose long side is parallel to the vertical line OX. Of these five regions, a region including the center of the imaging surface 20 is defined as a first region 60a. In addition, two regions adjacent to the first region 60a are defined as a second region 60b. Further, the remaining two areas adjacent to the left and right ends of the imaging surface 20 are defined as a third area 60c. In the present embodiment, a plurality of focus detection pixel columns 61 in which focus detection pixels are arranged in a line in the left-right direction (X-axis direction) are provided in the first region 60a, the second region 60b, and the third region 60c.

  The second region 60b has a longer distance from the optical axis of the imaging optical system 110 in the left-right direction (X-axis direction) than the first region 60a. That is, the second area 60b is an area having a higher image height than the first area 60a. The third region 60c has a longer distance from the optical axis of the imaging optical system 110 in the left-right direction (X-axis direction) than the first region 60a and the second region 60b. That is, the third region 60c is a region having a higher image height than the first region 60a and the second region 60b.

  FIG. 8 shows an enlarged view of a part of the first region 60a. In FIG. 8, the letters “R”, “G”, and “B” represent the imaging and focus detection pixels 301 having the red, green, and blue color filters 32, and are referred to as “NL” and “NR”. The characters represent the first focus detection pixels 302NL and 302NR, respectively.

  As shown in FIG. 8, in the focus detection pixel row 61N in the first region 60a, the first focus detection pixels 302NL and 302NR are alternately arranged at regular intervals d along the left-right direction (X-axis direction). Has been. For example, from left to right, a first focus detection pixel 302NL, a plurality of imaging and focus detection pixels 301a, a first focus detection pixel 302NR, a plurality of imaging and focus detection pixels 301a, a first focus detection pixel 302NL,. Thus, the pixels 30 are arranged. That is, a part of the imaging / focus detection pixel 301 is replaced with the first focus detection pixels 302NL and 302NR in the first region 60a.

  As shown in FIG. 7, the second region 60b is provided with more focus detection pixel rows 61 than the first region 60a. FIG. 9 shows an enlarged view of a part of the second region 60b. In FIG. 9, the second focus detection pixels 302SL and 302SR and the third focus detection pixels 302LL and 302LR are represented by letters “SL”, “SR”, “LL”, and “LR”, respectively. In the second region 60b, a plurality of three types of focus detection pixel columns 61, that is, a focus detection pixel column 61N, a focus detection pixel column 61S, and a focus detection pixel column 61L are provided.

  In the focus detection pixel column 61N, the first focus detection pixels 302NL and 302NR are alternately arranged at regular intervals d along the left-right direction (X-axis direction). In the focus detection pixel row 61S, the second focus detection pixels 302SL and 302SR are alternately arranged at regular intervals d along the left-right direction (X-axis direction). In the focus detection pixel column 61L, the third focus detection pixels 302LL and 302LR are alternately arranged at regular intervals d along the left-right direction (X-axis direction). That is, in the second region 60b, a part of the imaging / focus detection pixel 301 is replaced with the first focus detection pixels 302NL and 302NR, the second focus detection pixels 302SL and 302SR, and the third focus detection pixels 302LL and 302LR. Yes.

  As shown in FIG. 7, in the third region 60c, more focus detection pixel columns 61 are provided than in the second region 60b. FIG. 10 shows an enlarged view of a part in the third region 60c. In FIG. 10, the fourth focus detection pixels 302SNL and 302SNR and the fifth focus detection pixels 302LNL and 302LNR are represented by letters “SNL”, “SNR”, “LNL”, and “LNR”, respectively. In the third region 60c, a total of five types of focus detections of a focus detection pixel column 61N, a focus detection pixel column 61S, a focus detection pixel column 61L, a focus detection pixel column 61SN, and a focus detection pixel column 61LN are included. A plurality of pixel columns 61 are provided.

  In the focus detection pixel column 61SN, the fourth focus detection pixels 302SNL and 302SNR are alternately arranged at regular intervals d along the left-right direction (X-axis direction). In the focus detection pixel column 61LN, fifth focus detection pixels 302LNL and 302LNR are alternately arranged at regular intervals d along the left-right direction (X-axis direction). That is, in the third region 60c, some of the imaging and focus detection pixels 301 are the first focus detection pixels 302NL and 302NR, the second focus detection pixels 302SL and 302SR, the third focus detection pixels 302LL and 302LR, and the fourth focus. The detection pixels 302SNL and 302SNR are replaced with fifth focus detection pixels 302LNL and 302LNR.

  Next, focus detection processing by the first focus detection unit 221 and the second focus detection unit 222 will be described. At the start of the focus detection process, one focus detection area is set in advance on the shooting screen. For example, the focus detection area may be manually set by a user using an operation member such as a button (not shown), or may be automatically set by the body CPU 220 by a known main subject recognition process such as face recognition.

  In the focus detection process, first, the second focus detection unit 222 performs a focus detection calculation based on the focus detection signal output from the focus detection pixel 302 in the focus detection area. This focus detection calculation is suitable for detection of large defocus, that is, a state in which the focus is greatly deviated compared to the focus detection calculation performed by the first focus detection unit 221 (details will be described later). Therefore, in the following description, the focus detection calculation performed by the second focus detection unit 222 is referred to as a focus detection calculation for large defocus.

  When a defocus amount of a predetermined amount or more is detected by the second focus detection unit 222, that is, when a large defocus is detected, the focus adjustment unit 230 drives the focusing lens 112 based on the detection result. On the other hand, when a defocus amount less than a predetermined amount is detected, that is, when the imaging optical system 110 is in focus to some extent, the first focus detection unit 221 performs imaging and focus detection pixels in the focus detection area. A focus detection calculation based on the focus detection signal output from 301 is performed. Then, the focus adjustment unit 230 drives the focusing lens 112 based on the detection result. Here, the focus detection calculation performed by the first focus detection unit 221 is more suitable for focus detection when the defocus is not large than the focus detection calculation performed by the second focus detection unit 222 (details will be described later). Therefore, in the following description, the focus detection calculation performed by the first focus detection unit 221 is referred to as a focus detection calculation for small defocus.

  Hereinafter, focus detection calculation for large defocus performed by the second focus detection unit 222 will be described. The second focus detection unit 222 first selects the focus detection pixel row 61 corresponding to the position of the exit pupil of the imaging optical system 110 from the vicinity of the focus detection area. For example, when the focus detection area is near the center of the shooting screen and only the focus detection pixel column 61N is in the vicinity thereof, the focus detection pixel column 61N is inevitably selected.

  On the other hand, when the focus detection area is at a position away from the center of the shooting screen and there are three focus detection pixel rows 61L, 61N, and 61S in the vicinity thereof, the focus detection area depends on the position of the exit pupil of the imaging optical system 110. One focus detection pixel column 61 is selected from the levers. Specifically, when the exit pupil of the imaging optical system 110 is at a relatively distant position (at a position distant from a predetermined distance), the focus detection pixel row 61L is selected. On the contrary, when the exit pupil of the imaging optical system 110 is in a relatively close position (a close position within a predetermined distance), the focus detection pixel row 61S is selected. If neither of them (in an intermediate position), the focus detection pixel column 61N is selected.

  Next, the second focus detection unit 222 acquires a focus detection signal from the focus detection pixels in the selected focus detection pixel row 61. For example, if the focus detection pixel column 61N is selected, the first focus detection pixels 302NL and 302NR are arranged in a line in the focus detection pixel column 61N. The second focus detection unit 222 outputs an output signal in which outputs of a large number of first focus detection pixels 302NL (light reception outputs of the photoelectric conversion unit 34) are arranged, and outputs of a large number of first focus detection pixels 302NR (of the photoelectric conversion unit 34). A pair of signals with an output signal in which the light reception outputs are arranged are defined as a pair of focus detection signals. Then, a correlation calculation is performed to calculate a phase difference between the pair of focus detection signals, and a defocus amount is calculated. Since such calculation is well known, description thereof is omitted.

  The focus detection calculation performed by the second focus detection unit 222 is suitable for focus detection at the time of large defocus. The photoelectric conversion unit 34 of the focus detection pixel 302 is shielded by the light shielding member 35 except for a part thereof. It depends. The focus detection signal obtained from the imaging and focus detection pixel 301 is a gentle signal with a clear contrast when the focus of the imaging optical system 110 is greatly out of focus (that is, when the defocus amount is very large). Become. It is difficult to accurately detect the phase difference of such a signal by correlation calculation.

  On the other hand, in the photoelectric conversion unit 34 of the focus detection pixel 302, the incident light is limited by the light blocking member 35, and the focus detection direction (X-axis direction) in the range in which the light beam that has passed through the imaging optical system 110 enters. Is smaller than the width in the same direction of the photoelectric conversion units 34L and 34R included in the imaging and focus detection pixel 301.

  In general, when the aperture stop 130 of the imaging optical system 110 is made a small stop, the depth of field becomes deep and a subject image with a small amount of blur can be obtained, but the focus detection pixel 302 can also obtain the same effect. . That is, even when the imaging optical system 110 is greatly out of focus (that is, when the defocus amount is very large), the focus detection signal obtained from the focus detection pixel 302 is obtained from the imaging and focus detection pixel 301. Compared to the obtained focus detection signal, the signal has a higher contrast (a steeper, more accurate representation of the original subject image). With such a signal, it is easier to perform phase difference detection by correlation calculation than the focus detection signal obtained from the imaging and focus detection pixel 301. Therefore, even when the focus is greatly deviated, accurate focus detection calculation can be performed as compared with the imaging and focus detection pixel 301.

  As described above, since the second focus detection unit 222 selects an appropriate focus detection pixel array 61 according to the position of the exit pupil of the imaging optical system 110, the light flux from the exit pupil is kicked and focus detection is performed. Will no longer cause problems. In the first region 60a, even when the exit pupil of the imaging optical system 110 is far, the incident angle of the light beam from the exit pupil in the X-axis direction is smaller than that in the second region 60b and the third region 60c. Since it does not become so large, the light beam from the exit pupil is not kicked even in the focus detection pixel row 61N, and the focus detection pixel row 61N can sufficiently cope with it. Accordingly, only the focus detection pixel column 61N is arranged in the first region 60a. The number of types of focus detection pixels arranged in the second region 60b is smaller than that in the third region 60c for the same reason.

  Next, the focus detection calculation for small defocusing performed by the first focus detection unit 221 will be described. The first focus detection unit 221 first acquires a focus detection signal from the imaging / focus detection pixel 301 in the vicinity of the focus detection area. For example, a large number of imaging and focus detection pixels 301 arranged in a horizontal row near the focus detection area are selected. Then, an output signal in which the light reception outputs of the photoelectric conversion units 34L of the selected imaging / focus detection pixels 301 are arranged, and an output signal in which the light reception outputs of the photoelectric conversion units 34R of the imaging / focus detection pixels 301 are arranged, Are a pair of focus detection signals. The first focus detection unit 221 performs correlation calculation to calculate the phase difference between the pair of focus detection signals, and calculates the defocus amount. Since such calculation is well known, description thereof is omitted.

  Unlike the photoelectric conversion unit 34 of the focus detection pixel 302, the photoelectric conversion units 34L and 34R of the imaging and focus detection pixel 301 are not limited in the amount of incident light. Therefore, the amount of photoelectrically converted light is larger than that of the focus detection pixel 302. That is, the signal amount of the focus detection signal is larger than that of the focus detection pixel 302. Therefore, when the defocus amount is small to some extent, the defocus amount obtained by the second focus detection unit 222 by the focus detection calculation is more accurate than the defocus amount obtained by the first focus detection unit 221 by the focus detection calculation. Is good. Therefore, in the present embodiment, focus adjustment is performed based on the result of focus detection by the first focus detection unit 221 during small defocus.

  FIG. 11 is a flowchart of control processing executed by the body CPU 220. When the camera body 200 is powered on, the body CPU 220 reads a control program including this control process from the ROM 240 and starts execution.

  First, in step S10, the body CPU 220 starts periodic operation of the image sensor 210, that is, reading of an image signal every predetermined time (for example, 1/60 second) for creating a live view image. In step S20, the body CPU 220 determines whether or not a predetermined automatic focus adjustment operation (for example, a half-press operation of the release switch) has been performed. If the automatic focus adjustment operation has not been performed, the body CPU 220 advances the process to step S30.

  In step S30, the body CPU 220 reads an imaging signal for creating a live view image from the imaging and focus detection pixels of the imaging device 210. The imaging signal read out here is a signal for creating a live view image, and it is not necessary to read out signals from all imaging and focus detection pixels. For example, thinning readout is performed every three pixels. In step S40, the body CPU 220 updates the live view image displayed on the display device 250. That is, a live view image is created and displayed on the display device 250 based on the imaging signal read in step S30. Thereafter, the body CPU 220 advances the process to step S20.

  On the other hand, if the automatic focus adjustment operation is not performed in step S20, the body CPU 220 advances the process to step S50. In step S50, the body CPU 220 executes an automatic focus adjustment (AF) process described later. In step S60, the body CPU 220 determines whether or not a predetermined release operation (for example, a full-press operation of the release switch) has been performed. If the release operation has not been performed, the body CPU 220 advances the process to step S70.

  In step S <b> 70, the body CPU 220 reads an imaging signal for creating a live view image from the imaging / focus detection pixels of the imaging device 210. In step S80, the body CPU 220 updates the live view image displayed on the display device 250. That is, a live view image is created and displayed on the display device 250 based on the imaging signal read in step S70. Thereafter, the body CPU 220 advances the process to step S20.

  On the other hand, if a release operation has been performed in step S60, body CPU 220 advances the process to step S90. In step S <b> 90, the body CPU 220 reads an imaging signal from the imaging / focus detection pixel 301 of the imaging element 210. The imaging signal read out here is a signal of recorded image data (main image data). Since it is desirable that the recorded image data has as high image quality as possible, signals are read from all the imaging and focus detection pixels 301. In step S <b> 100, the body CPU 220 performs interpolation of the focus detection pixel 302. That is, since an imaging signal cannot be obtained from the position where the focus detection pixel 302 exists, an imaging signal that should be obtained from that position (if the imaging and focus detection pixel 301 exists at that position) Are generated on the basis of the imaging signal obtained from the imaging and focus detection pixel 301.

  In step S110, the body CPU 220 creates recording image data and stores it in a storage medium (not shown) (for example, a memory card). In step S120, the body CPU 220 determines whether or not a predetermined power-off operation (for example, a power switch pressing operation) has been performed. If the power-off operation has not been performed, the body CPU 220 advances the process to step S20. On the other hand, when the power-off operation is performed, the body CPU 220 ends the process of FIG.

  FIG. 12 is a flowchart of AF processing called from step S30 in FIG. First, in step S200, the second focus detection unit 222 selects one focus detection pixel row from the focus detection pixel row in the vicinity of the focus detection area, based on information (for example, the exit pupil position) of the current imaging optical system 110. To do. For example, when the focus detection area is located in the third region 60c and the exit pupil of the imaging optical system 110 is far away to some extent, the focus detection pixel row 61L is selected. Information on the current imaging optical system 110 may be received by the body CPU 220 from the lens CPU 120 through data communication between the lens CPU 120 and the body CPU 220.

  In step S210, the second focus detection unit 222 reads a focus detection signal from the focus detection pixels 302 included in the focus detection pixel row selected in step S200. In step S220, the second focus detection unit 222 performs focus detection calculation based on the focus detection signal read in step S210, that is, focus detection calculation for large defocus.

  In step S230, the second focus detection unit 222 determines whether or not a defocus amount of a predetermined amount or more, that is, a large defocus is detected by the focus detection calculation for large defocus performed in step S220. If a defocus amount equal to or greater than the predetermined amount has been detected, the second focus detection unit 222 advances the process to step S240. In step S240, the focus adjustment unit 230 drives the focusing lens 112 based on the defocus amount obtained by the focus detection calculation for large defocus. Thereafter, the second focus detection unit 222 proceeds with the process to step S200.

  On the other hand, if a defocus amount greater than or equal to the predetermined amount is not detected in step S230 (such as when the detected defocus amount is less than the predetermined amount or the defocus amount cannot be detected), the second The focus detection unit 222 advances the process to step S250. In step S250, the first focus detection unit 221 reads a light reception signal (light reception output) from the imaging / focus detection pixel 301. As described above, the signal read here is a signal that can be handled as an imaging signal and can also be handled as a focus detection signal.

  In step S260, the body CPU 220 updates the live view image displayed on the display device 250. That is, the signal read in step S250 is handled as an imaging signal, a live view image is created and displayed on the display device 250. In step S <b> 270, the first focus detection unit 221 selects one pixel row including the imaging / focus detection pixels 301 arranged in the focus detection direction (X-axis direction) from the vicinity of the focus detection area. In step S280, the first focus detection unit 221 uses, as a focus detection signal, a signal corresponding to the pixel column selected in step S270 among the signals read out in step S250, that is, a focus detection calculation based on the focus detection signal, that is, a small image. Performs focus detection calculation for focus.

  In step S290, the body CPU 220 determines whether or not the focus detection calculation for small defocusing performed in step S280 is successful. For example, if the phase difference cannot be detected due to the low contrast of the subject image and the focus detection fails, the body CPU 220 advances the process to step S300. In step S300, the body CPU 220 determines whether or not the most recent focus detection calculation for large defocusing performed in step S220 has been successful. If the defocus amount has been successfully calculated by the most recent focus detection calculation for large defocus, the body CPU 220 advances the process to step S310.

  In step S310, the focus adjustment unit 230 drives the focusing lens 112 based on the defocus amount obtained by the focus detection calculation for large defocus. Thereafter, body CPU 220 advances the process to step S200.

  In step S300, when the focus detection calculation for the last large defocus has failed to calculate the defocus amount, the body CPU 220 advances the process to step S320. In step S320, the focus adjustment unit 230 performs so-called search driving (scan driving) in which the focusing lens is moved over a certain range. Thereafter, body CPU 220 advances the process to step S200.

  In step S290, when the focus detection calculation for small defocusing performed in step S280 is successful, the body CPU 220 advances the process to step S330. In step S330, the body CPU 220 determines whether the imaging optical system 110 is in focus, that is, whether the defocus amount detected in step S280 is sufficiently small (smaller than a predetermined threshold value). To do. If it is not in focus, that is, if the defocus amount is greater than or equal to a predetermined threshold, the body CPU 220 advances the process to step S340. In step S340, the focus adjustment unit 230 drives the focusing lens 112 based on the defocus amount obtained by the focus detection calculation for small defocus. Thereafter, body CPU 220 advances the process to step S250. The reason why the process proceeds to step S250 instead of step S200 is that it is clear that the focus has already been achieved to some extent (not in the large defocus state). If the in-focus state is determined in step S330, that is, if the defocus amount is smaller than the predetermined threshold value, the body CPU 220 ends the AF process. As described above, in the AF processing of the present embodiment, first, focus detection calculation for large defocus is performed, and when a large defocus state is detected, focus detection for small defocus that is likely to fail is performed. The lens is driven based on the result of the focus detection calculation for large defocus without performing the calculation.

According to the camera system according to the first embodiment described above, the following operational effects can be obtained.
(1) The imaging element 210 has a plurality of imaging and focus detection pixels 301 in which incident light is incident in a predetermined range, and a plurality of types of focus detection in which incident light is incident in a range smaller than the imaging and focus detection pixels 301. Pixels 302 are arranged. The image sensor 210 includes a first region 60a in which one type of focus detection pixel 302 is disposed, and a second region in which a type of focus detection pixel 302 having a higher image height than the first region 60a and greater than the first region 60a is disposed. Region 60b. Since it did in this way, focus detection can be appropriately performed even in a large defocus state or a small defocus state.

(2) The plurality of types of focus detection pixels 302 have a width in the predetermined direction of the opening smaller than that of the imaging and focus detection pixels 301. Since it did in this way, focus detection can be appropriately performed even in a large defocus state or a small defocus state.

(3) The first focus detection pixels 302NR and 302NL corresponding to the first exit pupil position are disposed in the first region 60a, and the first focus detection pixels 302NR and 302NL are disposed in the second region 60b. Second focus detection pixels 302SR and 302SL corresponding to a second exit pupil position different from the exit pupil position are arranged. Since it did in this way, focus detection can be appropriately performed even when the position of the exit pupil changes due to, for example, replacement of the interchangeable lens 100 with another type.

(4) The distance in the X-axis direction from the optical axis of the imaging optical system 110 (center of the imaging surface 20) to the first region 60a is the optical axis of the imaging optical system 110 in the same direction (center of the imaging surface 20). Is shorter than the distance from the second region 60b. Since it did in this way, only the minimum focus detection pixel 302 can be arrange | positioned in the position where a subject light is unlikely to be kicked, and the image quality of picked-up image data improves.

(5) The imaging device 210 corresponds to the first exit pupil position where the incident light is incident on a range smaller than the imaging / focus detection pixel 301 and the imaging / focus detection pixel 301 in which incident light is incident on a predetermined range. The first focus detection pixels 302NR and NL and the second focus detection pixel 302SR corresponding to a second exit pupil position different from the first exit pupil position when incident light is incident in a range smaller than the imaging and focus detection pixel 301. , SL. The image sensor 210 includes a first region 60a in which the first focus detection pixels 302NR and NL are arranged, an image height higher than that of the first region 60a, and the first focus detection pixels 302NR and NL and the second focus detection pixels 302SR and SL. 2nd area | region 60b where this is arrange | positioned. Since it did in this way, compared with the case where the two photoelectric conversion parts 34 are provided in the single focus detection pixel 302, manufacture of the image pick-up element 210 becomes easy.

(6) The image sensor 210 receives the first focus detection pixel 302NR and the second focus detection pixel 302SR that receive light from one of the pair of exit pupils, and the first focus that receives light from the other of the pair of exit pupils. A detection pixel 302NL and a second focus detection pixel 302SL. Since it did in this way, it is not necessary to deform | transform the photoelectric conversion part 34 separately, and the manufacturing cost of the image pick-up element 210 is reduced.

(7) The image sensor 210 has third image detection pixels LR and LL in which incident light is incident in a range smaller than the image capture and focus detection pixel 301, and the first image detection pixel having a higher image height than the second region 60b. 302NR, NL, second focus detection pixels 302SR, SL, and a third region 60c in which the third focus detection pixels 302LR, LL are arranged. Since it did in this way, more fine focus detection can be performed according to the exit pupil position.

(8) A plurality of types of focus detection pixels 302 are arranged in the X-axis direction. Since it did in this way, the focus detection of a phase difference detection system can be performed.

(9) The first focus detection unit 221 performs focus detection based on the focus detection signal output from the imaging and focus detection pixel 301. When the exit pupil of the imaging optical system 110 is at the first position, the second focus detection unit 222 performs focus detection based on the focus detection signals (photoelectric conversion signals) output from the first focus detection pixels 302NR and 302NL. When the exit pupil of the imaging optical system 110 is at the second position, focus detection is performed based on the focus detection signals output from the second focus detection pixels 302SR and 302SL. Since this is done, an appropriate focus is always obtained regardless of whether it is in a small defocus state or a large defocus state, or whether the exit pupil of the imaging optical system 110 is in the first position or the second position. Detection can be performed.

(10) The focus adjustment unit 230 adjusts the focus of the imaging optical system 110 based on the focus detection result when the focus detection result by the second focus detection unit 222 represents a defocus of a predetermined amount or more. If the focus detection result by the second focus detection unit 222 does not indicate a defocus of a predetermined amount or more, the focus adjustment of the imaging optical system 110 is performed based on the focus detection result by the first focus detection unit 221. Do. Since it did in this way, when it is in a large defocus state, it is not necessary to operate the 1st focus detection part 221, and the processing load of body CPU220 can be reduced and power consumption can be reduced.

(Second Embodiment)
The camera system according to the second embodiment has the same configuration as the camera system according to the first embodiment, but the content of the AF processing executed by the body CPU 220 is the same as that of the first embodiment. Is different. Hereinafter, the AF processing in the second embodiment will be described.

  FIG. 13 is a flowchart of AF processing called from step S50 of FIG. 11 in the present embodiment. First, in step S <b> 400, the first focus detection unit 221 reads a light reception signal (light reception output) from the imaging / focus detection pixel 301. As described above, the signal read here is a signal that can be handled as an imaging signal and can also be handled as a focus detection signal.

  In step S410, the body CPU 220 updates the live view image displayed on the display device 250. That is, the signal read in step S400 is treated as an imaging signal, and a live view image is created and displayed on the display device 250.

  In step S415, the first focus detection unit 221 selects one pixel row including the imaging and focus detection pixels 301 arranged in the focus detection direction (X-axis direction) from the vicinity of the focus detection area. In step S420, the first focus detection unit 221 uses, as a focus detection signal, a signal corresponding to the pixel column selected in step S415 among the signals read out in step S400, that is, a focus detection calculation based on the focus detection signal, that is, small data. Performs focus detection calculation for focus.

  In step S430, the body CPU 220 determines whether or not the focus detection calculation for small defocusing performed in step S420 is successful. For example, when the phase difference detection cannot be performed because the imaging optical system 110 is greatly out of focus, that is, in a large defocus state or the like, and the focus detection fails, the body CPU 220 advances the process to step S440.

  In step S440, the second focus detection unit 222 selects one focus detection pixel row from the focus detection pixel row in the vicinity of the focus detection area based on the information (for example, the exit pupil position) of the current imaging optical system 110. . In step S450, the second focus detection unit 222 reads a focus detection signal from the focus detection pixels 302 included in the focus detection pixel row selected in step S440. In step S460, the second focus detection unit 222 performs focus detection calculation based on the focus detection signal read in step S450, that is, focus detection calculation for large defocus.

  In step S470, the body CPU 220 determines whether or not the focus detection calculation for large defocusing performed in step S460 is successful. If focus detection fails, the body CPU 220 advances the process to step S490. In step S490, the focus adjustment unit 230 performs so-called search driving (scan driving) in which the focusing lens is moved over a certain range. Thereafter, body CPU 220 advances the process to step S400.

  On the other hand, if the defocus amount has been successfully calculated by the focus detection calculation for large defocus in step S470, the body CPU 220 advances the process to step S480. In step S480, the focus adjustment unit 230 drives the focusing lens 112 based on the defocus amount obtained by the focus detection calculation for large defocus. Thereafter, body CPU 220 advances the process to step S400.

  If the calculation of the defocus amount by the focus detection calculation for small defocus is successful in step S430, the body CPU 220 advances the process to step S500. In step S500, the body CPU 220 determines whether or not the imaging optical system 110 is in focus, that is, whether or not the defocus amount detected in step S420 is sufficiently small (smaller than a predetermined threshold value). To do. If it is not in focus, that is, if the defocus amount is greater than or equal to a predetermined threshold, the body CPU 220 advances the process to step S510. In step S510, the focus adjustment unit 230 drives the focusing lens 112 based on the defocus amount obtained by the focus detection calculation for small defocus. Thereafter, body CPU 220 advances the process to step S400. On the other hand, if the in-focus state is obtained in step S500, that is, if the defocus amount is smaller than the predetermined threshold value, the body CPU 220 ends the process shown in FIG. As described above, in the AF processing of the present embodiment, first, focus detection calculation for small defocus is performed, and focus detection calculation for large defocus is performed only when this fails.

According to the camera system according to the second embodiment described above, the following operational effects can be obtained.
(1) When the focus detection by the first focus detection unit 221 is successful, the focus adjustment unit 230 adjusts the focus of the imaging optical system 110 based on the result of the focus detection, and the focus by the first focus detection unit 221. When the detection fails, the focus adjustment of the imaging optical system 110 is performed based on the result of focus detection by the second focus detection unit 222. Since it did in this way, the focus detection by the 2nd focus detection part 222 will be performed only at the time of a large defocus, and the processing load of body CPU220 can be reduced and power consumption can be reduced.

(Third embodiment)
The camera system according to the third embodiment has the same configuration as the camera system according to the first embodiment, but has an image sensor 210a having a structure different from that of the image sensor 210. This is different from the first embodiment. Hereinafter, the image sensor 210a according to the third embodiment will be described.

  FIG. 14 is a perspective view schematically showing the structure of the image sensor 210a according to the third embodiment. The image sensor 210 a includes a microlens array 211 and a photoelectric conversion array 212. The microlens array 211 has a plurality of microlenses 31 arranged in a two-dimensional square shape. The photoelectric conversion array 212 includes a plurality of photoelectric conversion units 34 that are two-dimensionally arranged in a square. Note that the arrangement of the plurality of microlenses 31 may not be a square arrangement.

  The microlens array 211 is disposed at a position away from the light receiving surface of the photoelectric conversion array 212 by the focal length f of the microlens 31. In other words, the microlens array 211 and the photoelectric conversion array 212 are arranged so that the focal position of the microlens 31 and the light receiving surface of the photoelectric conversion array 212 coincide.

  In the present embodiment, the diameter of one microlens 31 is larger than the width of one photoelectric conversion unit 34. That is, a plurality of photoelectric conversion units 34 are covered by one microlens 31. The subject light that has passed through one microlens 31 enters a plurality of photoelectric conversion units 34 corresponding to the microlens 31. As illustrated in FIG. 14, a plurality of photoelectric conversion units 34 are included in a range 215 in which light passing through one microlens 31 is incident.

  The image sensor 210 a has a plurality of pixels 30. The pixel 30 includes two types of pixels: an imaging / focus detection pixel 301 used for both imaging and focus detection, and a focus detection pixel 302 used only for focus detection. Hereinafter, these two types of pixels will be described.

  FIG. 15 is a cross-sectional view schematically showing the imaging / focus detection pixel 301 and the focus detection pixel 302. Note that FIG. 15 schematically illustrates a cross section of the central portion of the imaging surface of the imaging element 210a. In the first embodiment, one pixel 30 has one microlens 31. On the other hand, in the present embodiment, a plurality of pixels 30 share one microlens 31. In other words, in this embodiment, the microlens 31 included in one pixel 30 and the microlens 31 included in another pixel 30 may be the same microlens 31.

  The imaging / focus detection pixel 301 includes a micro lens 31, a color filter 32, and a photoelectric conversion unit 34. Incident light that has entered the microlens 31 enters the photoelectric conversion unit 34 via the color filter 32. The color filter 32 is formed so that each pixel transmits red, blue, or green light and does not transmit other light. The color filter 32 of the imaging / focus detection pixel 301 is configured to form a so-called Bayer array. The imaging / focus detection pixel 301 outputs the photoelectric conversion signal output by the photoelectric conversion unit 34.

  The imaging / focus detection pixel 301 according to the present embodiment is separated from the center of the imaging surface in the same manner as the imaging / focus detection pixel 301 according to the first embodiment shown in FIG. The position of the optical axis 41 of the microlens 31 and the center of the photoelectric conversion unit 34 are separated from each other, and the distance increases as the distance from the center of the imaging surface increases. Since this point is the same as that of the first embodiment, illustration and description thereof are omitted.

  The focus detection pixel 302 is the same as that of the first embodiment except that the microlens 31 is shared between the plurality of pixels 30. That is, the focus detection pixel 302 includes the micro lens 31, the color filter 32, the photoelectric conversion unit 34, and the light shielding member 35. Part of the incident light that has entered the microlens 31 is not blocked by the light blocking member 35 via the color filter 32 and enters the photoelectric conversion unit 34.

  Also in the present embodiment, as in the first embodiment, the focus detection pixel 302 includes the first focus detection pixels 302NL and 302NR, the second focus detection pixels 302SL and 302SR, and the third focus detection pixels 302LL and 302LR. , Fourth focus detection pixels 302SNL and 302SNR, and fifth focus detection pixels 302LNL and 302LNR are included. In the first embodiment, these focus detection pixels have a difference that the width of the opening is different, but in the present embodiment, the width of the opening is the same.

  FIG. 16 is an enlarged plan view of a part in the first region 60a (FIG. 7) of the image sensor 210a. In FIG. 16, the characters “R”, “G”, and “B” represent the imaging pixels 303 having the red, green, and blue color filters 32, respectively, and the characters “NL” and “NR” These represent the first focus detection pixels 302NL and 302NR, respectively.

  In the first embodiment, in the focus detection pixel column 61N in the first region 60a, the first focus detection pixels 302NL and 302NR are alternately arranged at regular intervals d along the left-right direction (X-axis direction). Was arranged. In the present embodiment, instead of the focus detection pixel row 61N, consider a microlens row 610N in which microlenses 31 including focus detection pixels 302 are arranged in a line in the left-right direction (X-axis direction). In the microlens 31 included in the microlens array 610N in the first region 60a, the first focus detection pixels 302NL and 302NR are alternately arranged at regular intervals (every other in FIG. 16).

  For example, a total of 36 pixels 30 of 6 × 6 having the leftmost microlens 31a in FIG. 16 includes one first focus detection pixel 302NL. The total of 36 pixels 30 of 6 × 6 having the right microlens 31b does not include the focus detection pixel 302. Further, a total of 36 pixels 30 of 6 × 6 having the right microlens 31c on the right side includes one first focus detection pixel 302NR.

  The pair of first focus detection pixels 302NL and 302NR are arranged point-symmetrically with respect to the principal ray from the assumed exit pupil position in each microlens 31. For example, in the microlens array 610N shown in FIG. 16, the position of the principal ray from the assumed exit pupil position is indicated by a circle LP. When attention is paid to each microlens 31, the first focus detection pixel 302NL and the first focus detection pixel 302NR are arranged so as to be point-symmetric with respect to the circle LP. Specifically, the first focus detection pixel 302NL is disposed immediately below the circle LP, and the first focus detection pixel 302NR is disposed immediately above the circle LP.

  FIG. 17 is an enlarged plan view of a part in the second region 60b (FIG. 7) of the image sensor 210a. In FIG. 17, the second focus detection pixels 302SL and 302SR and the third focus detection pixels 302LL and 302LR are represented by letters “SL”, “SR”, “LL”, and “LR”, respectively. In the second region 60b, a plurality of three types of microlens arrays 61, that is, a microlens array 610L, a microlens array 610N, and a microlens array 610S, are provided.

  In the microlens 31 included in the microlens array 610N, the first focus detection pixels 302NL and 302NR are alternately arranged at regular intervals (every other in FIG. 17). In the microlens 31 included in the microlens array 610S, the second focus detection pixels 302SL and 302SR are alternately arranged at regular intervals (every other in FIG. 17). In the micro lenses 31 included in the micro lens array 610L, the third focus detection pixels 302LL and 302LR are alternately arranged at regular intervals (every other in FIG. 17).

  The pair of second focus detection pixels 302SL and 302SR and the pair of third focus detection pixels 302LL and 302LR are arranged point-symmetrically with respect to the principal ray from the assumed exit pupil position in each microlens 31. . For example, in the microlens array 610S shown in FIG. 17, the position of the principal ray from the assumed exit pupil position is indicated by a circle LP. When attention is paid to each microlens 31, the second focus detection pixel 302SL and the second focus detection pixel 302SR are arranged so as to be point-symmetric with respect to the circle LP. Specifically, the second focus detection pixel 302SL is disposed immediately below the circle LP, and the second focus detection pixel 302SR is disposed immediately above the circle LP. The same applies to the third focus detection pixels 302LL and 302LR.

  The first focus detection pixels 302NL and 302NR are disposed in the vicinity of the optical axis of the microlens 31. On the other hand, the second focus detection pixels 302SL and 302SR are arranged at positions away from the optical axis of the microlens 31 by a certain distance in the right direction on the paper surface. Similarly, the third focus detection pixels 302LL and 302LR are arranged at positions away from the optical axis of the microlens 31 by a fixed distance in the left direction of the paper (the direction opposite to the second focus detection pixels 302SL and 302SR).

  Thus, in the present embodiment, the position where the focus detection pixel 302 is arranged differs depending on the assumed pupil position. That is, the focus detection pixel 302 is disposed at a position corresponding to the assumed pupil position. For example, since light from the exit pupil position assumed by the first focus detection pixels 302NL and 302NR forms a spot near the center of the microlens 31, the first focus detection pixels 302NL and 302NR are near the center of the microlens 31. Placed in. On the other hand, since the second focus detection pixels 302SL and 302SR assuming a short pupil position form a spot on the side closer to the optical axis of the imaging element 210a than the optical axis of the microlens 31, that is, the left side in FIG. The second focus detection pixels 302SL and 302SR are arranged on the right side of the optical axis of the micro lens 31. The third focus detection pixels 302LL and 302LR are vice versa, and are arranged on the left side of the optical axis of the microlens 31.

  FIG. 18 is an enlarged plan view of a part of the third region 60c (FIG. 7) of the image sensor 210a. In FIG. 18, the fourth focus detection pixels 302SNL and 302SNR and the fifth focus detection pixels 302LNL and 302LNR are represented by characters “SNL”, “SNR”, “LNL”, and “LNR”, respectively. In the third region 60c, there are a plurality of microlens arrays 610 of a microlens array 610S, microlens array 610SN, microlens array 610N, microlens array 610LN, and microlens array 610L, Is provided.

  In the microlens 31 included in the microlens array 610N, the first focus detection pixels 302NL and 302NR are alternately arranged at regular intervals (every other in FIG. 18). In the microlens 31 included in the microlens array 610S, the second focus detection pixels 302SL and 302SR are alternately arranged at regular intervals (every other in FIG. 18). In the microlens 31 included in the microlens array 610L, the third focus detection pixels 302LL and 302LR are alternately arranged at regular intervals (every other in FIG. 18). In the microlens 31 included in the microlens array 610SN, the fourth focus detection pixels 302SNL and 302SNR are alternately arranged at regular intervals (every other in FIG. 18). In the microlens 31 included in the microlens array 610LN, the fifth focus detection pixels 302LNL and 302LNR are alternately arranged at regular intervals (every other in FIG. 18).

  The pair of fourth focus detection pixels 302SNL and 302SNR and the pair of fifth focus detection pixels 302LNL and 302LNR are arranged point-symmetrically with respect to the principal ray from the assumed exit pupil position in each microlens 31. . For example, in the microlens array 610SN shown in FIG. 18, the position of the principal ray from the assumed exit pupil position is indicated by a circle LP. When attention is paid to each microlens 31, the fourth focus detection pixel 302SNL and the fourth focus detection pixel 302SNR are arranged so as to be point-symmetric with respect to the circle LP. Specifically, the fourth focus detection pixel 302SNL is disposed immediately below the circle LP, and the fourth focus detection pixel 302SNR is disposed immediately above the circle LP. The same applies to the fifth focus detection pixels 302LNL and 302LNR.

  The fourth focus detection pixels 302SNL and 302SNR are arranged at positions away from the optical axis of the microlens 31 by a certain distance in the right direction on the paper surface. The distance from the optical axis of the micro lens 31 is shorter than the second focus detection pixels 302SL and 302SR. Similarly, the fifth focus detection pixels 302LNL and 302LNR are arranged at positions away from the optical axis of the microlens 31 by a fixed distance in the left direction of the paper (the direction opposite to the fourth focus detection pixels 302SNL and 302SNR). The distance from the optical axis of the microlens 31 is shorter than the third focus detection pixels 302LL and 302LR.

  When the imaging device 210a configured as described above is used, an image of an arbitrary image plane (so-called refocus image) within a predetermined range in the optical axis direction is synthesized from the imaging signal output from the imaging / focus detection pixel 301. A so-called refocus function can be realized. Hereinafter, the refocus function will be described.

  FIG. 19 is a cross-sectional view schematically showing the light flux from the light spot P on the image plane S to be synthesized and the image sensor 210a. In FIG. 19, a light spot P provided on the image plane S to be synthesized is considered. The spread angle θ of light from the light spot P toward the image sensor 12 is defined by the size of the pupil of the imaging optical system 110 (that is, the aperture value of the imaging optical system 110). The aperture value of the micro lens 31 is configured to be the same as or smaller than the aperture value of the imaging optical system 110. Therefore, the light beam emitted from the light spot P and incident on a certain microlens 31 does not spread outside the region covered with the microlens 31.

  Here, as shown in FIG. 19, if the light beam from the light spot P is incident on the five microlenses 31 (1) to 31 (5), the microlenses 31 (1) to 31 (5) are incident on the microlenses 31 (1) to 31 (5). By integrating the incident light quantity (photoelectric conversion output of the photoelectric conversion units 34 (1) to 34 (5)) on the light receiving surface of the incident light beams 300 (1) to 300 (5), the pupil from the light spot P is integrated. A limited total amount of incident light is obtained. That is, the amount of light at the light spot P (the pixel to be synthesized) on the image plane S to be synthesized is obtained.

  The body CPU 220 sets a plurality of light spots P on the designated image plane S, and specifies, for each light spot P, the microlens 31 on which the light beam from the light spot P is incident. The body CPU 220 identifies which photoelectric conversion unit 34 the light beam from the light spot P is incident on for each identified microlens 31. The body CPU 220 calculates the pixel value of the light spot P by integrating the photoelectric conversion outputs of the specified photoelectric conversion unit 34. In addition, when the specified photoelectric conversion unit 34 is the photoelectric conversion unit 34 of the focus detection pixel 302, instead of the photoelectric conversion output from the photoelectric conversion unit 34, photoelectric conversion by the surrounding photoelectric conversion unit 34 is performed. It is desirable to use a photoelectric conversion output obtained by performing an interpolation operation based on the output.

  Through the above processing, the image of the image plane S designated as the synthesis target is synthesized. The body CPU 220 can synthesize images of a plurality of different image planes with the imaging signal output from the imaging device 210a by one imaging. That is, an image having a plurality of image planes can be obtained from one imaging result.

  By the way, there is a certain restriction on the position of the image plane that can be suitably combined while maintaining a certain resolution by the above processing. For example, it is known that when the image plane near the apex of the microlens 31 is synthesized, the resolution is lower than when the image planes at other positions are synthesized. Thus, there are restrictions on the position of the image plane that can be combined. Therefore, the body CPU 220 recognizes main subjects included in the imaging range by using a well-known subject recognition technique or the like so that these main subjects are included in a range in which the main subjects can be suitably combined (hereinafter simply referred to as a compositible range). Then, the focusing lens 112 is driven. The focus adjustment in the present embodiment refers to adjusting the position of the focusing lens 112 so that the main subject is included in the compositable range as described above.

  Next, the focus detection calculation for small defocusing performed by the first focus detection unit 221 will be described. The first focus detection unit 221 first acquires a focus detection signal from the imaging / focus detection pixel 301 in the vicinity of the focus detection area. For example, a large number of microlenses 31 arranged in a horizontal row near the focus detection area are selected. Then, for each of the selected microlenses 31, a signal obtained by adding the light reception output of the photoelectric conversion unit 34 of the imaging / focus detection pixel 301 arranged in the left half of the microlens 31 and the right half of the microlens 31 are displayed. A signal obtained by adding the light reception outputs of the photoelectric conversion units 34 of the arranged imaging and focus detection pixels 301 is generated. These pair of signals can be handled as a pair of focus detection signals in the same manner as the light reception outputs of the photoelectric conversion units 34L and 34R in the first embodiment. The first focus detection unit 221 performs correlation calculation to calculate the phase difference between the pair of focus detection signals, and calculates the defocus amount. Since such calculation is well known, description thereof is omitted.

  In the above description, the light reception outputs of the photoelectric conversion units 34 of the imaging and focus detection pixels 301 arranged in the left and right halves of the microlens 31 are added, but by reducing the number of photoelectric conversion units 34 used for the addition, A focus detection signal can be obtained as if the amount of incident light was limited. The smaller the number of photoelectric conversion units 34 used for addition, the better the response to large defocusing. On the other hand, the signal amount of the focus detection signal becomes smaller and the accuracy becomes worse. Therefore, for example, at the time of small defocusing, it is desirable to add the light reception outputs from many photoelectric conversion units 34. On the other hand, by generating a pair of focus detection signals using only the light reception outputs from the two (a pair of) photoelectric conversion units 34, it is possible to cope with a large defocus.

  Further, in the case of large defocus, there is a possibility that focus detection cannot be performed even with a pair of focus detection signals using only the light reception outputs from the two (pair) photoelectric conversion units 34. In such a case, in the present embodiment, the focus adjustment is performed using the result of the focus detection calculation for large defocusing performed by the second focus detection unit 222.

  Next, the focus detection calculation for large defocusing performed by the second focus detection unit 222 will be described. First, the second focus detection unit 222 selects the microlens array 610 corresponding to the position of the exit pupil of the imaging optical system 110 from the vicinity of the focus detection area. For example, when the focus detection area is near the center of the shooting screen and only the micro lens array 610N is in the vicinity, the micro lens array 610N is inevitably selected.

  On the other hand, when the focus detection area is at a position away from the center of the shooting screen and there are three microlens arrays 610S, 610N, and 610L in the vicinity thereof, the focus detection area depends on the position of the exit pupil of the imaging optical system 110. One microlens array 610 is selected from among them. Specifically, when the exit pupil of the imaging optical system 110 is at a relatively distant position (at a position distant from a predetermined distance), the microlens array 610L is selected. On the other hand, when the exit pupil of the imaging optical system 110 is at a relatively close position (a close position within a predetermined distance), the microlens array 610S is selected. If neither is present (in an intermediate position), the microlens array 610N is selected.

  Next, the second focus detection unit 222 acquires a focus detection signal from the focus detection pixels 302 in the selected microlens array 610. For example, if the micro lens array 610N is selected, the first focus detection pixels 302NL and 302NR are arranged in a line in the micro lens array 610N. The second focus detection unit 222 outputs an output signal in which outputs of a large number of first focus detection pixels 302NL (light reception outputs of the photoelectric conversion unit 34) are arranged, and outputs of a large number of first focus detection pixels 302NR (of the photoelectric conversion unit 34). A pair of signals with an output signal in which the light reception outputs are arranged are defined as a pair of focus detection signals. Then, a correlation calculation is performed to calculate a phase difference between the pair of focus detection signals, and a defocus amount is calculated. Since such calculation is well known, description thereof is omitted.

  Since the opening of the pair of focus detection signals obtained here is limited by the light shielding member 35, the pair of focus detection signals is more than the pair of focus detection signals using only the light reception outputs from the two (a pair of) photoelectric conversion units 34 described above. Further, this is a focus detection signal that can cope with large defocus.

According to the camera system of the third embodiment described above, the following operational effects can be obtained.
(1) A focus detection pixel 302 and a plurality of imaging / focus detection pixels 301 into which light having passed through a certain microlens 31 is incident, and a focus detection pixel 302 and a plurality of imaging / injection in which light having passed through another microlens 31 is incident A focus detection pixel 301 is provided. As described above, even in a so-called refocus camera, appropriate focus detection can be performed even in a large defocus state or a small defocus state.

  The following modifications are also within the scope of the present invention, and one or a plurality of modifications can be combined with the above-described embodiment.

(Modification 1)
In the embodiment described above, the light shielding member 35 having an opening with a predetermined width is provided in the focus detection pixel 302. In this way, instead of providing the light shielding member 35, the width of the photoelectric conversion unit 34 may be actually reduced.

  FIG. 20A illustrates a first focus detection pixel 302NR ′ having a photoelectric conversion unit 34NR formed in accordance with the position and size of the opening 36NR instead of the light shielding member 35 having the opening 36NR.

  The first focus detection pixel 302NR and the first focus detection pixel 302NL may be a single pixel having a pair of photoelectric conversion units. That is, for each pixel, a photoelectric conversion unit 34 having a size corresponding to the opening 36NR is provided at a position corresponding to the opening 36NR, and another size corresponding to the opening 36NL is provided at a position corresponding to the opening 36NL. The photoelectric conversion unit 34 may be provided to replace the first focus detection pixels 302NR and NL in the embodiment described above. The same applies to the second to fifth focus detection pixels.

  Alternatively, a pair of photoelectric conversion units 34L and 34R similar to the imaging and focus detection pixel 301 may be provided for one pixel, and both the openings 36NL and NR may be provided in the light shielding member 35. The same applies to the second to fifth focus detection pixels.

(Modification 3)
When the light shielding member 35 is provided in the focus detection pixel 302, there is a possibility that a light beam that has not entered the photoelectric conversion unit 34 (light beam that has entered the light shielding member 35) leaks into the adjacent imaging and focus detection pixel 301. In order to prevent such stray light, an antireflection film may be provided on the surface of the light shielding member 35. FIG. 20B illustrates a first focus detection pixel 302NR ″ in which an antireflection film 37 is provided on the surface of the light shielding member 35.

(Modification 4)
The number of types, the number of arrangement, and the arrangement of the focus detection pixels 302 may be different from those in the above-described embodiment. Similarly, the number of types, the number of arrangement, the shape, and the arrangement pattern of the areas where the focus detection pixels 302 are arranged as exemplified as the first area 60a, the second area 60b, and the third area 60c are different from those of the above-described embodiment. Also good.

  FIG. 21A shows an example in which the first region 60a, the second region 60b, and the third region 60c are arranged in an arc shape. FIG. 21B shows an example in which the first region 60a, the second region 60b, and the third region 60c are arranged concentrically. As described above, various shapes and arrangement patterns of the area where the focus detection pixels 302 are arranged can be considered.

(Modification 5)
The shape of the pair of photoelectric conversion units 34R and 34L included in the imaging / focus detection pixel 301 may be different from that illustrated in FIG. For example, it may be rectangular as illustrated in FIG. Further, the focus detection direction is not limited to the X-axis direction, and may be, for example, the Y-axis direction. In this case, for example, as illustrated in FIG. 22B, a pair of photoelectric conversion units 34T and 34B divided in the Y-axis direction may be provided.

  Furthermore, both the X-axis direction and the Y-axis direction can be used as the focus detection direction. For example, as illustrated in FIG. 22C, four photoelectric conversion units 34a, 34b, 34c, and 34d are provided. At this time, if the light reception signals of the two photoelectric conversion units 34a and 34c arranged on the left side of the sheet are added, a signal corresponding to the light reception signal of the photoelectric conversion unit 34L illustrated in FIG. Further, if the light reception signals of the two photoelectric conversion units 34a and 34b arranged on the upper side of the sheet are added, a signal corresponding to the light reception signal of the photoelectric conversion unit 34T illustrated in FIG. 22B is obtained. Accordingly, as shown in FIG. 22 (c), the image pickup and focus detection pixel 301 is configured, and the photoelectric conversion in which the widths of the four photoelectric conversion units 34a, 34b, 34c, and 34d in the X-axis direction and the Y-axis direction are reduced. If the focus detection pixel 302 having a portion is provided, both the X-axis direction and the Y-axis direction become the focus detection direction.

  As long as the characteristics of the present invention are not impaired, the present invention is not limited to the above-described embodiments, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

DESCRIPTION OF SYMBOLS 1 ... Camera system, 100 ... Interchangeable lens, 110 ... Imaging optical system, 112 ... Focusing lens, 120 ... Lens CPU, 130 ... Aperture, 200 ... Camera body, 210 ... Imaging element, 220 ... Body CPU, 221 ... 1st Focus detection unit, 222 ... second focus detection unit, 230 ... focus adjustment unit, 240 ... ROM, 250 ... display device, 301, 301a, 301b ... imaging and focus detection pixel, 302 ... focus detection pixel

Claims (9)

A first focus detection pixel into which light from the imaging optical system is incident through a first opening provided at a first position of the light shielding film;
A second focus detection pixel in which light from the photographing optical system is incident through a second opening provided at a second position different from the first position of the light shielding film;
A pixel unit provided with a first region in which the first focus detection pixel is disposed and a second region in which the image height is higher than that of the first region and in which the first focus detection pixel and the second focus detection pixel are disposed. When,
An imaging device having The imaging device according to claim 1,
The first focus detection pixel receives light from one of the first exit pupils of the imaging optical system or light from the other of the first exit pupils through the first opening.
The second focus detection pixel is an image sensor in which light from one of the second exit pupils of the imaging optical system or light from the other of the second exit pupils is incident through the second opening. The imaging device according to claim 1 or 2,
In the pixel portion, an imaging pixel on which light from the photographing optical system is incident is further arranged,
A width of the first opening and the second opening in the first direction is a first width,
The imaging element in which a width in which light is incident on the imaging pixel in the first direction is a second width larger than the first width. The imaging device according to claim 3,
The imaging element in which a distance in the first direction from the optical axis of the photographing optical system to the first region is shorter than a distance in the first direction from the optical axis to the second region. In the imaging device according to claim 3 or 4,
An imaging device in which a plurality of the first focus detection pixels and the second focus detection pixels are arranged along the first direction. In the imaging device according to any one of claims 3 to 5,
The pixel unit further includes a first microlens and a second microlens,
The light that has passed through the first microlens is incident on a group of the imaging pixels and at least one first focus detection pixel,
The light that has passed through the second microlens is incident on a group of the imaging pixels different from the first microlens and at least one second focus detection pixel. In the imaging device according to any one of claims 1 to 6,
A third focus detection pixel on which light from the imaging optical system is incident through a third opening provided at a third position different from the first position and the second position of the light shielding film;
The pixel unit further includes a third region having an image height higher than that of the second region and in which the first focus detection pixel, the second focus detection pixel, and the third focus detection pixel are arranged. . A plurality of imaging pixels to which incident light is incident and a plurality of types of focus detection pixels, and a pixel unit in which the pixel units are arranged;
The pixel unit includes a first region in which a predetermined type of the focus detection pixel is disposed, and a type of the focus detection pixel having a higher image height than the first region and greater than the predetermined type disposed in the first region. An image sensor having a second region to be arranged. The image sensor according to any one of claims 1 to 7,
When the exit pupil of the imaging optical system is at the first exit pupil position, focus detection is performed based on the focus detection signal output from the first focus detection pixel, and the exit pupil of the imaging optical system is the second exit pupil. A focus detection unit that performs focus detection based on a focus detection signal output from the second focus detection pixel when in position;
With electronic camera.

Images