Image sensor

Abstract

To obtain an image sensor that can appropriately detect focus even in the peripheral areas of the photoelectric conversion region. [Solution] The image sensor comprises a first microlens into which light is incident, a second microlens into which light is incident, a first photoelectric conversion region that converts light from the first microlens into electric charge, a second photoelectric conversion region that converts light from the second microlens into electric charge, and a light-shielding member that blocks light, and is arranged such that the light-receiving area of ​​the first photoelectric conversion region that receives light from the first microlens and the light-receiving area of ​​the second photoelectric conversion region that receives light from the second microlens have different light-receiving areas, the first photoelectric conversion region has a first photoelectric conversion unit that converts light into electric charge, and a second photoelectric conversion unit that converts light into electric charge, the second photoelectric conversion region has a third photoelectric conversion unit that converts light into electric charge, and a fourth photoelectric conversion unit that converts light into electric charge.

Description

Technical Field

[0001] The present invention relates to an imaging device.

Background Art

[0002] There is known a technique in which pixels provided with two photoelectric conversion units are arranged in a pixel region and focus detection is performed by the pupil division phase difference method (see Patent Document 1). In such a technique, it is difficult to perform focus detection on the signals of the pixels in the peripheral portion of the pixel region.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] An imaging device according to a first aspect of the present invention includes a first microlens into which light is incident, a second microlens into which light is incident, a first photoelectric conversion region that converts light from the first microlens into electric charges, a second photoelectric conversion region that converts light from the second microlens into electric charges, and a member that blocks light, the light blocking member being arranged so that a light receiving area of the first photoelectric conversion region that receives light from the first microlens and a light receiving area of the second photoelectric conversion region that receives light from the second microlens are different light receiving areas, the first photoelectric conversion region having a first photoelectric conversion unit that converts light into electric charges and a second photoelectric conversion unit that converts light into electric charges, and the second photoelectric conversion region having a third photoelectric conversion unit that converts light into electric charges and a fourth photoelectric conversion unit that converts light into electric charges.

Brief Description of the Drawings

[0005] [Figure 1] It is a cross-sectional view showing a main part configuration of a digital camera according to an embodiment. [Figure 2] It is a plan view for explaining an imaging device. [Figure 3]Figures 3(a) to 3(c) are enlarged cross-sectional views of pixels. [Figure 4] This is a circuit diagram of the pixels and surrounding circuits. [Figure 5] This is a magnified view of a portion of the pixel array. [Figure 6] This is a diagram illustrating a color filter. [Figure 7] Figure 7(a) is a diagram illustrating a dedicated pixel, and Figure 7(b) is a magnified view showing a dedicated pixel in detail. [Figure 8] This is a magnified view showing the dedicated pixels in detail. [Figure 9] Figure 9(a) is a diagram illustrating a dedicated pixel, and Figure 9(b) is a magnified view showing a dedicated pixel in detail. [Figure 10] This is a magnified view showing the dedicated pixels in detail. [Figure 11] This is a cross-sectional view of an image sensor used to illustrate the focus detection light beam using the pupil-splitting phase-difference method. [Figure 12] This is a cross-sectional view of an image sensor used to illustrate the focus detection light beam using the pupil-splitting phase-difference method. [Figure 13] This diagram illustrates dedicated pixels. [Figure 14] Figures 14(a) and 14(b) illustrate the distance measuring pupil plane and distance measuring pupil. [Figure 15] This is a magnified view of a portion of the pixel arrangement in Modification Example 2. [Figure 16] This is an enlarged view showing dedicated pixels for large defocus. [Figure 17] This is a diagram illustrating multiple dedicated pixels. [Figure 18] This diagram illustrates the first example in which dedicated pixels are discretely arranged. [Figure 19] This figure illustrates a second example in which dedicated pixels are discretely arranged. [Figure 20] This diagram illustrates a third example in which dedicated pixels are discretely arranged. [Figure 21] This figure illustrates the dedicated pixels in modified example 6. [Figure 22]It is a diagram illustrating dedicated pixels in Modification 6. [Figure 23] FIG. 23(a) is a diagram illustrating the front of a smartphone, and FIG. 23(b) is a diagram illustrating the back of a smartphone. [Figure 24] It is a diagram illustrating the appearance of glasses-type wearable devices.

Mode for Carrying Out the Invention

[0006] In a solid-state imaging device according to an embodiment, pixels having a plurality of photoelectric conversion units for one microlens are arranged over the entire photoelectric conversion region where the solid-state imaging device generates an image. In the central portion of the photoelectric conversion region, a pair of photoelectric conversion signals read out for each pixel are used for focus detection by the pupil division phase difference method.

[0007] In the central portion of the photoelectric conversion region, light is incident substantially perpendicularly to the photoelectric conversion unit, whereas in the peripheral portion (where the image height is larger than that in the central portion) located outside the central portion of the photoelectric conversion region, light is incident obliquely to the photoelectric conversion unit. For this reason, a plurality of dedicated pixels suitable for the case where light is incident obliquely are provided in advance in the peripheral portion of the photoelectric conversion region. Thereby, it becomes possible to appropriately perform focus detection by the pupil division phase difference method also in the peripheral portion of the photoelectric conversion region. Hereinafter, it will be described in detail with reference to the drawings.

[0008] <Main Configuration of Digital Camera> As an electronic device equipped with the solid-state imaging device according to the present embodiment, an interchangeable-lens digital camera will be described as an example. FIG. 1 is a cross-sectional view showing the main configuration of a digital camera 201. The digital camera 201 is composed of an imaging lens 202 and a camera body 203. The imaging lens 202 is attached to the camera body 203 via a mount portion 204. Note that it may be a lens-integrated type digital camera 201 in which the imaging lens 202 and the camera body 203 are integrally formed instead of the interchangeable-lens type.

[0009] The imaging lens 202 includes a lens 209, a zooming lens 208, a focusing lens 210, an aperture 211, and a lens control device 206. The imaging lens 202 forms an image of a subject image on an imaging element 212 on the camera body 203 side. The aperture 211 restricts the subject light beam passing through the imaging lens 202 by changing the aperture diameter around the optical axis Ax.

[0010] The lens control device 206 is composed of a microcomputer, a memory, a drive control circuit, etc., which are not shown in the figure. The lens control device 206 controls the lens drive for moving the focusing lens 210 forward and backward in the direction of the optical axis Ax during focus adjustment, and controls the aperture drive for changing the aperture diameter of the aperture 211 during aperture adjustment. In addition, the lens control device 206 also performs position detection of the zooming lens 208 and the focusing lens 210, and detection of the aperture diameter of the aperture 211.

[0011] The lens control device 206 further communicates with a body control device 214, which will be described later. In this communication, lens information (such as lens position and aperture diameter of the aperture 211) is transmitted from the imaging lens 202 to the camera body 203, and camera information (such as defocus amount and aperture value) is transmitted from the camera body 203 to the imaging lens 202.

[0012] The camera body 203 includes an imaging element 212, a body control device 214, a liquid crystal display element drive circuit 215, a liquid crystal display element 216, and an eyepiece lens 217, and a memory card 219 is configured to be detachable. The imaging element 212 is a solid-state imaging element in which pixels having a photoelectric conversion unit are arranged two-dimensionally. Details of the imaging element 212 will be described later.

[0013] The body control device 214 consists of a microcomputer (not shown), memory, drive control circuit, etc. The body control device 214 controls the overall operation of the digital camera 201, including exposure control of the image sensor 212, reading out the signal photoelectrically converted by the image sensor 212, focus detection calculation based on the signal read out from the image sensor 212, focus adjustment of the imaging lens 202 using the focus detection calculation result, image processing of the signal read out from the image sensor 212, and recording of the image data after image processing. The body control device 214 also communicates with the lens control device 206 in the imaging lens 202 via electrical contacts 213. The communication content is the lens information and camera information described above.

[0014] The liquid crystal display element 216 functions as an EVF (Electronic View Finder). The liquid crystal display element driving circuit 215 displays a live view image on the liquid crystal display element 216 based on a signal read from the image sensor 212. The live view image is a monitor image that is repeatedly captured at a predetermined frame rate (e.g., 30fps) prior to capturing for recording. The photographer observes the live view image displayed on the liquid crystal display element 216 through the eyepiece lens 217.

[0015] The memory card 219 is a recording medium for storing image data and the like. The body control device 214 performs the recording of image data to the memory card 219 and the reading of image data recorded on the memory card 219.

[0016] In the digital camera 201 described above, a subject image is formed on the light-receiving surface of the image sensor 212 by the light beam passing through the imaging lens 202. The subject image is photoelectrically converted (imaged) by the image sensor 212. The image signal and the focus detection signal are read out from the image sensor 212 and sent to the body control device 214.

[0017] The body control device 214 detects the amount of image misalignment between a pair of signals based on the focus detection signal read from the image sensor 212, and calculates the amount of defocus based on the detected amount of image misalignment. If the amount of defocus exceeds an acceptable value, the body control device 214 determines that the image is not in focus and sends the amount of defocus and a lens drive instruction to the lens control device 206 of the imaging lens 202. The lens control device 206 drives the focusing lens 210 by the amount of defocus, thereby performing autofocus (AF) adjustment.

[0018] <Image sensor description> Figure 2 is a plan view illustrating the image sensor 212. Figure 3(a) is an enlarged cross-sectional view of a pixel 300. In the image sensor 212 of Figure 2, pixels 300 are arranged two-dimensionally within the image generation region 212a. Each pixel 300 in Figure 3(a) has two photoelectric conversion units S1 and S2 for one microlens 10. The light-receiving areas of the photoelectric conversion units S1 and S2 are configured to be approximately equal. In this embodiment, an example is described in which pixels 300, each having two photoelectric conversion units S1 and S2 arranged horizontally, are arranged across the entire region 212a of Figure 2.

[0019] Each of the photoelectric conversion units S1 and S2 in the pixel 300 performs photoelectric conversion according to the drive signal from the peripheral circuit and outputs the photoelectrically converted signal. Figure 4 is a circuit diagram of the pixel 300 and the peripheral circuit. Each of the photoelectric conversion units S1 and S2 is composed of a photodiode.

[0020] The photoelectric conversion units S1 and S2 of pixel 300 each generate charge corresponding to the incident light. The charge generated by photoelectric conversion unit S1 is transferred via transfer transistor Txn1 to the FD (Floating Diffusion) region located on the vertical signal line 251 side. The FD region receives the charge and converts it into a voltage. The signal corresponding to the potential of the FD region is amplified by the amplification transistor AMP. Then, as the signal of the "row" selected by the "row" selection transistor SEL, it is read out via the vertical signal line 251. The reset transistor RES acts as a reset unit that resets the potential of the FD region.

[0021] Meanwhile, the charge generated by the photoelectric conversion unit S2 is transferred via the transfer transistor Txn2 to the FD (Floating Diffusion) region located on the vertical signal line 252 side. The FD region receives the charge and converts it into a voltage. The signal corresponding to the potential of the FD region is amplified by the amplification transistor AMP. Then, as the signal of the "row" selected by the "row" selection transistor SEL, it is read out via the vertical signal line 252. The reset transistor RES acts as a reset unit that resets the potential of the FD region. The peripheral circuit outputs the above drive signal at a predetermined timing according to instructions from the body control device 214.

[0022] Although the example given shows that the signal from the photoelectric conversion unit S1 is read out via the vertical signal line 251 and the signal from the photoelectric conversion unit S2 is read out via the vertical signal line 252, the signal from the photoelectric conversion unit S1 and the signal from the photoelectric conversion unit S2 may be configured to be read out via a single vertical signal line by using a common FD area between the photoelectric conversion unit S1 and the photoelectric conversion unit S2.

[0023] Returning to Figure 3(a), a light-shielding separator 20a is provided between the photoelectric conversion units S1 and S2. By providing the light-shielding separator 20a, light incident between the photoelectric conversion units S1 and S2 is blocked. If light is incident between the photoelectric conversion units S1 and S2, the incident light will leak into the photoelectric conversion units S1 and S2, reducing the degree of signal separation between the photoelectric conversion units S1 and S2. However, by providing the light-shielding separator 20a, the light incident between the photoelectric conversion units S1 and S2 is blocked, thus preventing a decrease in the degree of signal separation between the photoelectric conversion units S1 and S2.

[0024] In addition, instead of the triangular cross-sectional shape of the separating light-shielding member 20a exemplified in Figure 3(a), a trapezoidal cross-sectional shape of the separating light-shielding member 20b exemplified in Figure 3(b), or a bell-shaped cross-sectional shape of the separating light-shielding member 20c exemplified in Figure 3(c) may be provided. In any case, the separating light-shielding member is configured such that the upper width of its cross-sectional shape is narrower than the lower width of its cross-section so as not to obstruct light that directly enters the photoelectric conversion unit S1 or S2 from an oblique direction.

[0025] Figure 5 is an enlarged view of a portion of the array of pixels 300 located in region 212a. Figure 6 is an example of color filters 310 located at the positions of each pixel 300 in Figure 5. The color filters consist of three types of filters arranged in a Bayer array: red (R), green (G), and blue (B), each possessing spectral characteristics corresponding to its respective color.

[0026] The signal read from the pixel 300 in Figure 5, which is equipped with the color filter 310 in Figure 6, can be used as an image signal or as a focus detection signal. The body control device 214 switches between using the signal as an image signal and using it as a focus detection signal.

[0027] When acquiring a live view image or a recording image, the body control device 214 uses the signal read from the pixel 300 as the image signal. When using the signal read from the pixel 300 as the image signal, the body control device 214 uses the signal obtained by adding the signals from the two photoelectric conversion units S1 and S2 at each pixel 300 as the image signal at that pixel position.

[0028] When adjusting the focus, the body control device 214 uses the signal read from the pixel 300 corresponding to the set focus area as the focus detection signal. The focus area is the area from which phase difference information for focus detection using the pupil-splitting phase difference method is acquired, and is also called the focus detection area, distance measurement point, or autofocus (AF) point. For example, the body control device 214 reads the focus detection signal from the pixel 300 corresponding to the set focus area from among the 15 focus areas 101 that are pre-provided in the central part 400 (shown by the diagonal lines) of the region 212a in Figure 2.

[0029] <Dedicated pixels> In Figure 2, the peripheral portion 500 of region 212a, outside the central portion 400, is provided with the dedicated pixels described above. These dedicated pixels acquire phase difference information for focus detection using the pupil-splitting phase difference method. Since the image height H increases from the center outward in region 212a, dedicated pixels are provided in the peripheral portion 500 where the image height H is greater than that of the central portion 400. In the example in Figure 2, the central portion 400 is defined as the region enclosed by 4 / 5 of the length of each side of region 212a in the horizontal and vertical directions. The peripheral portion 500 is defined as the region 212a that is not included in the central portion 400.

[0030] The above 4 / 5 is just an example; it could also be 2 / 3. That is, the area enclosed by 2 / 3 of the length of each side of region 212a in the horizontal and vertical directions may be defined as the central part 400, and the area of ​​region 212a not included in the central part 400 may be defined as the peripheral part 500. Alternatively, instead of defining the boundary between the central part 400 and the peripheral part 500 based on the length of each side of region 212a, the boundary between the central part 400 and the peripheral part 500 may be defined based on the number of pixels from the outer edge pixel position in region 212a. For example, the peripheral part 500 could be defined as the area from the outer edge pixel position to 100 pixels, and the area inside this peripheral part 500 could be defined as the central part 400.

[0031] The dedicated pixel is a pixel 410 provided with a light-shielding member B, as illustrated in Figure 7(a), and outputs only a focus detection signal and no image signal. Figure 7(a) is a diagram illustrating the dedicated pixel 410 corresponding to the focus area 102 in Figure 2. In this embodiment, the dedicated pixel 410 or a dedicated pixel 420 (described later) is provided at positions corresponding to four focus areas 102 to 105 that are provided in advance for focus detection in the peripheral area 500. When the body control device 214 performs focus detection in the peripheral area 500, it uses the signal read from the dedicated pixel 410 (420) corresponding to the set focus area among the focus areas 102 to 105 as the focus detection signal.

[0032] (1) Example of arranging dedicated pixels horizontally In Figure 7(a), the dedicated pixels 410 are arranged horizontally, which is the same direction as the two photoelectric conversion units S1 and S2. The dedicated pixels 410 are positioned on the GB horizontal line where the green (G) and blue (B) of the color filter 310 illustrated in Figure 6 appear alternately. Instead of the green (G) and blue (B) color filters, light-shielding members B are provided at the positions of the dedicated pixels 410.

[0033] The light-shielding member B is provided so as to span between adjacent dedicated pixels 410. In the areas of the dedicated pixels 410 where the light-shielding member B is not provided, a white filter (not shown) is provided. The white filter has spectral characteristics corresponding to each color, for example, green (G), blue (B), and red (R), and transmits all visible light.

[0034] Figure 7(b) is a magnified view showing the dedicated pixel 410 in more detail. As described above, the pixels constituting the dedicated pixel 410 each have two photoelectric conversion units S1 and S2, similar to the pixels 300 adjacent to the dedicated pixel 410 above and below it.

[0035] The light-shielding member B blocks the light beam incident on the photoelectric conversion units S1 and S2 of the dedicated pixel 410 by covering part or all of them. The light-shielding member B may be composed of a shielding plate (film), a black filter, or a reflector (film), but in this specification it is referred to as a light-shielding member.

[0036] By providing the light-shielding member B, the ratio of light beams divided to the dedicated pixels 410 located on both the left and right sides of the light-shielding member B is different. In the example shown in Figure 7(b), the ratio of light beams distributed to the dedicated pixels 410 located on the right side of the light-shielding member B (further from the center of the image sensor 212) is made smaller than the ratio of light beams distributed to the dedicated pixels 410 located on the left side of the light-shielding member B (closer to the center of the image sensor 212). This makes it possible to perform focus detection, described later, appropriately at the position corresponding to the focus area 102 in the peripheral part 500 of region 212a.

[0037] The dedicated pixel 410 corresponding to the focus area 103 in Figure 2 is the same as the dedicated pixel 410 corresponding to the focus area 102 described above. However, the positional relationship between the photoelectric conversion units S1 and S2 of the dedicated pixel 410 and the light-shielding member B is reversed left to right.

[0038] Figure 8 is a magnified view showing in detail the dedicated pixels 410 corresponding to the focus area 103. In Figure 8, the ratio of light beam distributed to the dedicated pixels 410 located on the left side of the light-shielding member B (further from the center of the image sensor 212) is made smaller than the ratio of light beam distributed to the dedicated pixels 410 located on the right side of the light-shielding member B (closer to the center of the image sensor 212). This makes it possible to perform focus detection, described later, appropriately at the position corresponding to the focus area 103 in the peripheral part 500 of region 212a.

[0039] (2) Example of arranging dedicated pixels vertically Figure 9(a) is a diagram illustrating the dedicated pixels 420 corresponding to the focus area 104 in Figure 2. In Figure 9(a), the direction in which the dedicated pixels 420 are arranged is vertical, and is 90 degrees different from the direction in which the two photoelectric conversion units S1 and S2 are arranged. The dedicated pixels 420 are arranged on the GB vertical line in which the green (G) and blue (B) of the color filter 310 illustrated in Figure 6 appear alternately. Instead of the green (G) and blue (B) color filters, light-shielding members B are provided at the location of the dedicated pixels 420.

[0040] The light-shielding member B is provided so as to span between adjacent dedicated pixels 420. In the areas of the dedicated pixels 420 where the light-shielding member B is not provided, a white filter (not shown) is provided. As described above, the white filter transmits all visible light.

[0041] Figure 9(b) is a magnified view showing the dedicated pixel 420 in more detail. As described above, the pixels constituting the dedicated pixel 420, like the pixels 300 adjacent to the left and right of the dedicated pixel 420, each have two photoelectric conversion units S1 and S2.

[0042] The light-shielding member B blocks the light beam incident on the photoelectric conversion units S1 and S2 of the dedicated pixels 420 by covering part or all of them. By providing the light-shielding member B, the ratio of the light beam divided between the dedicated pixels 420 located on either the upper or lower side of the light-shielding member B is different. In the example shown in Figure 9(b), the ratio of the light beam distributed to the dedicated pixels 420 located below the light-shielding member B (further from the center of the image sensor 212) is made smaller than the ratio of the light beam distributed to the dedicated pixels 420 located above the light-shielding member B (closer to the center of the image sensor 212). This makes it possible to appropriately perform focus detection, as described later, at the position corresponding to the focus area 104 in the peripheral part 500 of region 212a.

[0043] The dedicated pixel 420 corresponding to the focus area 105 in Figure 2 is the same as the dedicated pixel 410 corresponding to the focus area 104 described above. However, the positional relationship between the photoelectric conversion units S1 and S2 of the dedicated pixel 420 and the light-shielding member B is reversed vertically.

[0044] Figure 10 is a magnified view showing in detail the dedicated pixels 420 corresponding to the focus area 105. In Figure 10, the ratio of light beam distributed to the dedicated pixels 420 located on the upper side of the light-shielding member B (further from the center of the image sensor 212) is made smaller than the ratio of light beam distributed to the dedicated pixels 420 located on the lower side of the light-shielding member B (closer to the center of the image sensor 212). This makes it possible to perform focus detection, described later, appropriately at the position corresponding to the focus area 105 in the peripheral part 500 of region 212a.

[0045] <About Phase-Detection AF (Autofocus) Operation> (1) When the signal from pixel 300 is used as the signal for focus detection. The body control device 214 uses the signal read from the pixel 300 corresponding to the set focus area from among the 15 focus areas 101 in the central part 400 of Figure 2 as the focus detection signal. Although the image sensor 212 can set a focus area at any position within region 212a, in this embodiment, the signal read from the pixel 300 corresponding to the set focus area from among the 15 focus areas 101 is used as the focus detection signal.

[0046] The body control device 214 uses the readout signals from the two photoelectric conversion units S1 and S2 at the pixel 300 corresponding to the focus area as the focus detection signal at that pixel position. The body control device 214 uses the focus detection signal to calculate the defocus amount as follows.

[0047] Figure 11 is a cross-sectional view of the image sensor 212 illustrating the focus detection light beam using the pupil-splitting phase difference method when setting the focus area 101 as exemplified in Figure 2. In Figure 11, pixels 300a to 300e are exemplified from the pixels 300. Each of pixels 300a to 300e has a microlens 10a to 10e and a photoelectric conversion unit S1a, S2a, S1b, S2b, S1c, S2c, S1d, S2d, S1e, and S2e.

[0048] The planar shapes of the photoelectric conversion units S1a, S1b, S1c, S1d, and S1e are projected onto a region 91 common to all of the photoelectric conversion units S1a, S1b, S1c, S1d, and S1e on the distance measuring pupil plane 90, which is spaced by the distance measuring pupil distance d from the microlenses 10a to 10e.

[0049] Furthermore, the planar shapes of the photoelectric conversion units S2a, S2b, S2c, S2d, and S2e are projected onto a region 92 common to all of the photoelectric conversion units S2a, S2b, S2c, S2d, and S2e on the distance measuring pupil plane 90, which is spaced by the distance measuring pupil distance d from the microlenses 10a to 10e.

[0050] The pair of regions 91 and 92 on the distance measuring pupil surface 90 onto which the above planar shapes are projected are called the distance measuring pupils. For the sake of simplicity, the distance measuring pupil surface 90 is assumed to be in substantially the same position as the exit pupil surface of the optical system of the imaging lens 202. That is, the distance measuring pupil distance d from the microlenses 10a to 10e to the distance measuring pupil surface 90 is assumed to be substantially equal to the exit pupil distance from the microlenses 10a to 10e to the exit pupil surface of the optical system of the imaging lens 202.

[0051] To explain using pixels 300c and 300d from pixels 300a to 300e as an example, pixel 300c receives the focus detection light beam 81 passing through the distance measuring pupil 91 and the microlens 10c by the photoelectric conversion unit S1c, and receives the focus detection light beam 82 passing through the distance measuring pupil 92 and the microlens 10c by the photoelectric conversion unit S2c.

[0052] Furthermore, the pixel 300d receives the focus detection light beam 71 passing through the distance measuring pupil 91 and the microlens 10d via the photoelectric conversion unit S1d, and also receives the focus detection light beam 72 passing through the distance measuring pupil 92 and the microlens 10d via the photoelectric conversion unit S2d.

[0053] The same applies to pixels 300a, 300b, and 300e in Figure 11, other than pixels 300c and 300d. As a result, the photoelectric conversion unit S1 in multiple pixels 300 outputs a signal corresponding to the intensity of the image formed by the focus detection light beam corresponding to the distance measuring pupil 91. In addition, the photoelectric conversion unit S2 in multiple pixels 300 outputs a signal corresponding to the intensity of the image formed by the focus detection light beam corresponding to the distance measuring pupil 92.

[0054] The body control device 214 obtains information indicating the intensity distribution of a pair of images formed by a pair of focus detection light beams passing through the distance measuring pupil 91 and distance measuring pupil 92, by combining a group of signal sequences output from each of the photoelectric conversion units S1 of the multiple pixels 300 and a group of signal sequences output from each of the photoelectric conversion units S2 of the multiple pixels 300.

[0055] The body control device 214 calculates the amount of image misalignment between the pair of images by performing image misalignment detection processing (correlation processing, phase difference detection processing) on ​​the intensity distribution of the pair of images. The body control device 214 further calculates the amount of defocus, which represents the focus adjustment state of the imaging lens 202, by multiplying the amount of image misalignment by a predetermined conversion coefficient. Since this type of defocus calculation using pupil-splitting phase difference is well known, a detailed explanation is omitted.

[0056] (2) When the signal from the dedicated pixels 410 in the peripheral area 500 is used as the focus detection signal. Next, we will explain the case in which the signal converted by photoelectric conversion by dedicated pixels 410 (Figure 7(a)) and 420 (Figure 9(a)) arranged in the peripheral area 500 of Figure 2 is used as the signal for focus detection.

[0057] The body control device 214 uses the signal read from the dedicated pixel 410 or 420 corresponding to the set focus area among the four focus areas 102 to 105 in the peripheral area 500 of Figure 2 as the focus detection signal. The body control device 214 uses the focus detection signal to calculate the defocus amount as follows.

[0058] Figure 12 is a cross-sectional view of the image sensor 212 illustrating the focus detection light beam using the pupil-splitting phase-difference method when the focus area 102 is set in the peripheral area 500 of Figure 2. In Figure 12, pixels 410g to 410k of the dedicated pixels 410 are shown as examples. Each of pixels 410g to 410k has a microlens 10g to 10k and a photoelectric conversion unit S1g, S2g, S1h, S2h, S1i, S2i, S1j, S2j, S1k, and S2k, respectively.

[0059] The planar shapes of the photoelectric conversion units S1h and S2h that are not covered by the light-shielding member B, and the planar shapes of the photoelectric conversion units S1j and S2j that are not covered by the light-shielding member B, are projected onto a region 91 on a distance measuring pupil surface 90 that is spaced by a distance measuring pupil distance d from the microlens distance measuring pupil surfaces 10g to 10k.

[0060] Furthermore, the planar shapes of the photoelectric conversion units S1i and S2i that are not covered by the light-shielding member B, and the planar shapes of the photoelectric conversion units S1k and S2k that are not covered by the light-shielding member B, are projected onto the region 92 on the distance measuring pupil plane 90, which is spaced by the distance measuring pupil distance d from the microlenses 10g to 10k.

[0061] Similar to the case in Figure 11, the pair of regions 91 and 92 on the distance-measuring pupil surface 90 onto which the above planar shapes are projected are called distance-measuring pupils. Furthermore, for the sake of simplicity, the distance-measuring pupil distance d from the microlenses 10g to 10k to the distance-measuring pupil surface 90 is considered to be substantially equal to the exit pupil distance from the microlenses 10g to 10k to the exit pupil surface of the optical system of the imaging lens 202.

[0062] To explain using pixels 410h to 410i from pixels 410g to 410k as an example, pixel 410h receives the focus detection light beam 181 passing through the distance measuring pupil 91 and the microlens 10h via photoelectric conversion units S1h and S2h. Pixel 410i receives the focus detection light beam 182 passing through the distance measuring pupil 92 and the microlens 10i via photoelectric conversion unit S2i.

[0063] The same applies to pixels 410j and 410k other than pixels 410h and 410i in Figure 12. As a result, in pixels 410h and 410j that constitute the dedicated pixels 410, the sum of the signals output by the respective photoelectric conversion units S1 and S2 corresponds to the intensity of the image formed by the focus detection light beam corresponding to the horizontally divided distance measuring pupil 91 in the distance measuring pupil plane 90. Furthermore, in pixels 410i and 410k that constitute the dedicated pixels 410, the sum of the signals output by the respective photoelectric conversion units S1 and S2 corresponds to the intensity of the image formed by the focus detection light beam corresponding to the horizontally divided distance measuring pupil 92 in the distance measuring pupil plane 90.

[0064] The body control device 214 obtains information indicating the intensity distribution of a pair of images formed by a pair of focus detection light beams passing through the distance measuring pupil 91 and the distance measuring pupil 92, by combining a group of signal sequences represented by the sum of signals obtained by pixels 410h and 410j constituting the dedicated pixel 410, and a group of signal sequences represented by the sum of signals obtained by pixels 410i and 410k constituting the dedicated pixel 410.

[0065] The method for calculating the defocus amount, which represents the focus adjustment state of the imaging lens 202, based on the intensity distribution of the pair of images described above, is the same as the method used when the signal from the pixel 300 is used as the focus detection signal as described in (1) above.

[0066] As explained with reference to Figure 12, when setting the focus area 102 in the peripheral area 500 of Figure 2, by using the dedicated pixels 410 arranged horizontally as exemplified in Figures 7(a) and 7(b), phase-detection AF based on horizontally divided metering pupils 91 and 92 can be performed in the peripheral area 500 of region 212a in Figure 2. Similarly, when setting the focus area 103 in the peripheral area 500 of Figure 2, by using the dedicated pixels 410 arranged horizontally as exemplified in Figure 8, phase-detection AF based on horizontally divided metering pupils 91 and 92 can be performed in the peripheral area 500 of region 212a in Figure 2.

[0067] Furthermore, although not shown in the diagram, when the focus area is set to region 104 in the peripheral area 500 of Figure 2, by using the dedicated pixels 420 arranged vertically as illustrated in Figures 9(a) and 9(b), phase-detection AF based on vertically divided distance measuring pupils can be performed in the peripheral area 500 of region 212a of Figure 2. Similarly, when the focus area is set to 105 in the peripheral area 500 of Figure 2, by using the dedicated pixels 420 arranged vertically as illustrated in Figure 10, phase-detection AF based on vertically divided distance measuring pupils 91 and 92 can be performed in the peripheral area 500 of region 212a of Figure 2.

[0068] <Regarding the acquisition of images for recording purposes> As described above, when acquiring a live view image or a recording image, the signal output from pixel 300 is used as the image signal. The dedicated pixels 410 and 420, as described above, output only focus detection signals, so there is a shortage of image signals at the locations of the dedicated pixels 410 and 420. Therefore, the body control device 214 performs interpolation processing to calculate the image signal for each pixel location that constitutes the dedicated pixels 410 and 420, using the readout signals from the two photoelectric conversion units S1 and S2 at the surrounding pixels 300 that are not dedicated pixels 410 and 420. Since such interpolation processing is well known, a detailed explanation of the interpolation processing will be omitted.

[0069] In this embodiment, the size of the photoelectric conversion units S1 and S2 in the dedicated pixels 410 and 420 is the same as the size of the photoelectric conversion units S1 and S2 in the normal pixels 300. As a result, the capacitance of the photoelectric conversion units S1 and S2 is the same between the normal pixels 300 and the dedicated pixels 410 (420), which reduces the processing burden for correcting the readout signal levels of the photoelectric conversion units S1 and S2 between the dedicated pixels 410 (420) and the normal pixels 300.

[0070] According to the above-described embodiment, the following effects and advantages can be obtained. (1) The image sensor 212 is arranged in two dimensions in the region 212a into which light from the imaging lens 202 is incident, and includes ordinary pixels 300 in which photoelectric conversion units S1 and S2 generate a signal for detecting the focus of the imaging lens 202, and dedicated pixels 410 (420) which are arranged in a part of the peripheral area 500 in which the image height H is greater than that of the center of the region 212a, and which are different from the ordinary pixels 300 in which the photoelectric conversion units S1 and S2 generate a signal for detecting the focus of the imaging lens 202. This makes it possible to appropriately detect the focus even in the peripheral area 500 of the region 212a in which the image height H is large.

[0071] (2) The image sensor 212 is arranged in two dimensions in the region 212a into which light from the imaging lens 202 is incident, and includes ordinary pixels 300 in which multiple photoelectric conversion units S1 and S2 each perform photoelectric conversion, and dedicated pixels 410 (420) arranged in the peripheral part 500 of the region 212a, in which photoelectric conversion units S1 and S2 perform photoelectric conversion for detecting the focus adjustment state of the imaging lens 202. This makes it possible to appropriately detect focus even in the peripheral part 500 which is near the outer edge of the region 212a.

[0072] (3) A normal pixel 300 converts the light beam that has passed through multiple different regions of the pupil of the imaging lens 202 into photoelectric signals using multiple photoelectric conversion units S1 and S2. As a result, the multiple photoelectric conversion signals output from the normal pixel 300 can be used as focus detection signals indicating the focus adjustment state. Furthermore, a standard pixel 300 may be configured to allow switching between outputting the photoelectric conversion signals from the two photoelectric conversion units S1 and S2 individually, and outputting the sum of the photoelectric conversion signals from the two photoelectric conversion units S1 and S2.

[0073] (4) The normal pixels 300 and the dedicated pixels 410 (420) perform photoelectric conversion using two photoelectric conversion units S1 and S2, respectively. In other words, pixels with two photoelectric conversion units S1 and S2 are arranged throughout the entire area 212a. As a result, a common element pattern can be used throughout the entire area when designing the image sensor 212, making the design easier compared to when different element patterns are used.

[0074] (5) The peripheral area 500 is an area of ​​100 pixels from the outer edge of region 212a, or an area within a predetermined range from the outer edge of region 212a (i.e., an area not included in the central area 400). This makes it possible to appropriately perform focus detection in the peripheral area 500, where focus detection is difficult using the photoelectric conversion signal output from the normal pixels 300, by using the photoelectric conversion signal output from the dedicated pixels 410 (420).

[0075] (6) The pixel 300 uses photoelectric conversion units S1 and S2 to photoelectrically convert the first and second light beams that have passed through the first and second regions of the pupil of the imaging lens 202, respectively. As a result, phase difference information for pupil-splitting phase difference focus detection can be obtained from the two photoelectric conversion signals output from the pixel 300.

[0076] (7) The dedicated pixels 410 (420) use the photoelectric conversion unit S1 and the photoelectric conversion unit S2 in one of the pair of pixels to photoelectrically convert the first light beam that has passed through the first region of the pupil of the imaging lens 202, and the photoelectric conversion unit S1 and the photoelectric conversion unit S2 in the other of the pair of pixels to photoelectrically convert the second light beam that has passed through the second region of the pupil of the imaging lens 202. As a result, phase difference information for pupil-splitting phase difference detection can be obtained using the signal obtained by adding the two photoelectric conversion signals output from one of the pair of pixels in the dedicated pixels 410 (420) and the signal obtained by adding the two photoelectric conversion signals output from the other of the pair of pixels in the dedicated pixels 410 (420).

[0077] (8) The dedicated pixels 410 (420) have a light-shielding member B that divides the incident light beam into the pair of pixels. In other words, the light-shielding member B allows the light beam to be appropriately divided between the pair of pixels in the dedicated pixels 410 (420).

[0078] (9) The light-shielding member B divides the incident light beam in the same direction as the alignment of the two photoelectric conversion units S1 and S2 in the dedicated pixel 410, so that pupil division can be performed in the same direction for both the normal pixel 300 and the dedicated pixel 410.

[0079] (10) The light-shielding member B divides the incident light beam in a direction that intersects with the direction in which the two photoelectric conversion units S1 and S2 in the dedicated pixel 420 are aligned, so that pupil division can be performed in different directions for the normal pixel 300 and the dedicated pixel 420.

[0080] (11) In the dedicated pixel 410, the two pairs of pixels are aligned in the same direction as the alignment of the two photoelectric conversion units S1 and S2 in that pixel, so that phase difference detection in the same direction is possible in both the normal pixel 300 and the dedicated pixel 410.

[0081] (12) In the dedicated pixel 420, the pair of pixels are arranged in a direction that intersects with the direction in which the two photoelectric conversion units S1 and S2 in that pixel are aligned, so that phase difference detection in different directions is possible for the normal pixel 300 and the dedicated pixel 420.

[0082] (13) In the dedicated pixels 410 (420), the positions of the light-shielding members B in the pair of pixels are determined based on the distance-measuring pupil distance d, so that pupil division can be performed appropriately in accordance with the distance-measuring pupil distance d of the imaging lens 202.

[0083] (14) In a normal pixel 300, a separation light-shielding member 20a that blocks incident light is provided between the two photoelectric conversion units S1 and S2, so that a decrease in the degree of signal separation between the photoelectric conversion unit S1 and the photoelectric conversion unit S2 can be avoided.

[0084] (15) The dedicated pixels 410 (420) are arranged in a predetermined ratio between the normal pixels 300. That is, the dedicated pixels 410 (420) are placed in positions corresponding to the four pre-defined focus areas 102 to 105 in the peripheral area 500, so that the number of positions where the image signal is insufficient can be kept to a minimum.

[0085] (16) The dedicated pixels 410 (420) are positioned on the GB line in the Bayer array color filter, making them less conspicuous compared to when they are arranged on the GR line.

[0086] The following modifications are also within the scope of the present invention, and it is possible to combine one or more of these modifications with the embodiments described above. (Variation 1) <Example of arranging dedicated pixels diagonally> In the embodiments described above, examples of dedicated pixels 410 arranged horizontally (in the direction in which the two photoelectric conversion units S1 and S2 are aligned) and dedicated pixels 420 arranged vertically (in the direction perpendicular to the direction in which the two photoelectric conversion units S1 and S2 are aligned) were explained. In addition to the examples described above, dedicated pixels may also be arranged in a direction 45 degrees different from the direction in which the two photoelectric conversion units S1 and S2 are aligned.

[0087] In the modified example 1, in addition to the dedicated pixels 410 and 420 described above, a dedicated pixel 430 (Figure 13) is pre-arranged in the peripheral portion 500 of the region 212a of the image sensor 212. Figure 13 is an example of a dedicated pixel 430. The dedicated pixel 430 is provided with light-shielding members B1 and B2 that diagonally straddle the space between adjacent dedicated pixels 430.

[0088] For example, when the body control device 214 sets focus areas 102 to 105 in the peripheral area 500 of Figure 2, it uses dedicated pixels 430 corresponding to the positions of focus areas 102 to 105 as focus detection pixels. In Figure 13, the dedicated pixels 430 correspond to focus area 104, for example.

[0089] In the dedicated pixel 430, by providing light-shielding members B1 and B2, the ratio of the light beam divided between the photoelectric conversion units S1 and S2 located above the light-shielding member B1 and the photoelectric conversion units S1 and S2 located below the light-shielding member B2 is different. Furthermore, the pixels constituting the dedicated pixel 430 each have two photoelectric conversion units S1 and S2, similar to the ordinary pixels 300 adjacent to the left and right of the dedicated pixel 430.

[0090] In the example shown in Figure 13, the ratio of light beam distributed to the dedicated pixels 430 located on the upper side of the light-shielding member B1 (further from the center of the image sensor 212) is made smaller than the ratio of light beam distributed to the dedicated pixels 430 located on the lower side of the light-shielding member B2 (closer to the center of the image sensor 212). This makes it possible to perform focus detection, as described later, at a position corresponding to the focus area 104 in the peripheral part 500 of region 212a.

[0091] In Modification 1, the sum of the pixel signals output by the photoelectric conversion units S1 and S2 of the dedicated pixel 430 located above the light-shielding member B1 corresponds to the intensity of the image formed by the focus detection light beam corresponding to the lower distance measuring pupil, which is divided diagonally in a distance measuring pupil plane (not shown). Also, the sum of the pixel signals output by the photoelectric conversion units S1 and S2 of the dedicated pixel 430 located below the light-shielding member B2 corresponds to the intensity of the image formed by the focus detection light beam corresponding to the upper distance measuring pupil, which is divided diagonally in a distance measuring pupil plane (not shown).

[0092] According to the modified example 1 described above, the following effects are achieved. Specifically, when the body control device 214 sets the focus area 104 in the peripheral area 500, it uses the dedicated pixels 430 arranged diagonally as illustrated in Figure 13, thereby enabling phase-detection autofocus based on diagonally divided distance measuring pupils in the peripheral area 500 of region 212a in Figure 2. Note that Figure 13 illustrates the case where the pixels are positioned at a 45-degree angle to the right, but dedicated pixels may also be arranged in a direction of a 45-degree angle to the left.

[0093] (Modification 2) <Pixels for large defocus> (1) In the case of a central section of 400 Figure 14(a) is an excerpt of the distance measuring pupil plane 90 and the divided distance measuring pupils 91 and 92 in Figure 11. In Figure 14(a), the width of the distance measuring pupils 91 and 92 in the direction of pupil alignment (horizontal direction in this example) is W1. Generally, a larger width W1 results in a larger amount of image blur during defocusing.

[0094] In particular, during periods of significant defocus, when the focusing lens 210 is far from the focus position, the amount of image blur can be so large that it becomes difficult to detect the amount of image misalignment between a pair of images. In Modification 2, to address this issue, the image sensor 212 is equipped with large defocus pixels 350 (Figure 15). Figure 15 is an enlarged view of a portion of the arrangement of pixels 300 in Modification 2. According to Figure 15, in region 212a of the image sensor 212, the large defocus pixels 350 are arranged at predetermined intervals (for example, one large defocus pixel 350 for every 100 pixels 300).

[0095] The large defocus pixel 350 has two photoelectric conversion units S1B and S2B behind one microlens (not shown). The horizontal width of the two horizontally aligned photoelectric conversion units S1B and S2B is narrower than the horizontal width of the two photoelectric conversion units S1 and S2 in a normal pixel 300. In the modified example 2, the large defocus pixel 350 is constructed by providing light-shielding members (not shown) having small openings above two photoelectric conversion units S1 and S2, which are the same size as those in a normal pixel 300.

[0096] When the planar shapes of the pair of photoelectric conversion units S1B and S2B of the large defocus pixel 350 are projected onto the distance measuring pupil surface 90 using a microlens (not shown), they correspond to the distance measuring pupils 91B and 92B in Figure 14(b), respectively. Figure 14(b) is a diagram illustrating the distance measuring pupil surface 90 and the distance measuring pupils 91B and 92B. The pair of photoelectric conversion units S1B and S2B of the large defocus pixel 350 divide the area into distance measuring pupils 91B and 92B.

[0097] Comparing Figure 14(b) with Figure 14(a), the width W2 of one of the distance measuring pupils (e.g., 92B) in the direction of alignment of distance measuring pupils 91B and 92B in the case of 350 large defocus pixels is smaller than the width W1 of one of the distance measuring pupils (e.g., 92) in the direction of alignment of distance measuring pupils 91 and 92 in the case of 300 normal pixels.

[0098] (2) In the case of the peripheral part 500 A large defocus pixel 450 is also provided in the dedicated pixel 410 located in the peripheral area 500. Figure 16 is an enlarged view showing the large defocus dedicated pixel 450 provided in the dedicated pixel 410 as illustrated in Figure 7(b). The opening 450d of the light-shielding member B provided in the large defocus dedicated pixel 450 is smaller than the opening 410d of the light-shielding member B provided in the normal dedicated pixel 410.

[0099] The aperture D of the aperture 450d of the light-shielding member B provided in the dedicated large defocus pixel 450 is defined as follows: Let L be the distance between the microlens (not shown) and the light-shielding member B, P be the spacing between pixels 300 (pixel pitch) (= horizontal width of the microlens), and n be the refractive index between the microlens and the light-shielding member B. The F-number of the microlens is expressed as F = L / (n × P).

[0100] Furthermore, when the diameter D of the aperture 450d of the light-shielding member B provided in the large defocus dedicated pixel 450 is to match the value of the aperture 211 of the imaging lens 202 (for example, F8), the value of the diameter D is set to D = F × P / 8. Furthermore, in case the F-number of the imaging lens 202, which is planned to be combined with the camera body 203, is different (for example, F5.6), a dedicated large defocus pixel 450b with an aperture of 450dB and a different diameter D may be provided. For example, to match the value of the aperture 211 of the imaging lens 202, F5.6, the value of the aperture Db of the 450dB aperture is set to Db = F × P / 5.6. Then, a dedicated large defocus pixel 450 with an aperture of D and a dedicated large defocus pixel 450b with an aperture of Db are provided, and either the dedicated large defocus pixel 450 or 450b is used depending on the F-number of the imaging lens 202 combined with the camera body 203.

[0101] According to the modified example 2 described above, the region 212a in Figure 2 includes a pixel 350 having two photoelectric conversion units S1B and S2B for pupil division in a large defocus state, and the peripheral part 500 of region 212a includes a dedicated pixel 450 for large defocus. This makes it easier to distinguish between so-called front focus and back focus even when the focus position is significantly off. In other words, with the large defocus pixel 350, the amount of image blur during defocus is less compared to the case of the normal pixel 300. Also, with the dedicated pixel 450 for large defocus, the amount of image blur during defocus is less compared to the case of the normal dedicated pixel 410.

[0102] In Figure 16, the shape of the opening 450d of the light-shielding member B provided in the large defocus dedicated pixel 450 is shown as a rectangle, but it may be a circular opening instead. Alternatively, the shape of the opening 450d of the light-shielding member B may be configured as an octagon.

[0103] (Variation 3) <Example of providing pixel rows with different positions for the light-shielding member B in a dedicated pixel> In the above explanation, for example, as illustrated in Figure 7(b), the ratio of light beam distributed to the dedicated pixel 410 located to the right of the light-shielding member B (further from the center of the image sensor 212) was made smaller than the ratio of light beam distributed to the dedicated pixel 410 located to the left of the light-shielding member B (closer to the center of the image sensor 212). In other words, the position of the light-shielding member B was shifted to the right relative to the positions of the two corresponding pixels 410.

[0104] The amount of displacement of the light-shielding member B is determined according to the distance-measuring pupil distance d described above. In this case, for example, when the focal length changes by moving the zooming lens 208, or when changing to an imaging lens 202 with a different focal length, it is conceivable that the amount of displacement of the light-shielding member B should be changed according to the distance-measuring pupil distance d of the imaging lens 202.

[0105] Therefore, in the modified example 3, a plurality of dedicated pixels 410A to 410C, each with a different amount of displacement of the light-shielding member B, are pre-provided on the image sensor 212, according to the distance-measuring pupil distance d of the imaging lens 202 which is planned to be combined with the camera body 203.

[0106] Figure 17 illustrates multiple dedicated pixels 410A to 410C. In Figure 17, each dedicated pixel 410A to 410C is positioned on a GB horizontal line where the green (G) and blue (B) of the color filter 310 appear alternately.

[0107] The dedicated pixel 410B distributes a smaller ratio of light beam to the pixel 410B located to the left of the light-shielding member B (closer to the center of the image sensor 212) than the ratio of light beam distributed to the pixel 410B located to the right of the light-shielding member B (further from the center of the image sensor 212). In other words, the position of the light-shielding member B is shifted to the left relative to the positions of the two corresponding pixels 410B.

[0108] The dedicated pixel 410A distributes light beams to pixels 410A located to the left and right of the light-shielding member B in approximately the same ratio. In other words, the position of the light-shielding member B is positioned midway between the positions of the two corresponding pixels 410A.

[0109] The dedicated pixel 410C distributes a ratio of light beam to the pixel 410C located to the right of the light-shielding member B (further from the center of the image sensor 212) less than the ratio of light beam distributed to the pixel 410C located to the left of the light-shielding member B (closer to the center of the image sensor 212). In other words, the position of the light-shielding member B is shifted to the right relative to the positions of the two corresponding pixels 410C.

[0110] When the body control device 214 sets a focus area 102 or 103 in the peripheral area 500 of region 212a, it selects a dedicated pixel from among the dedicated pixels 410A to 410C arranged in the peripheral area 500 that corresponds to the distance-measuring pupil distance d of the imaging lens 202.

[0111] According to the modified example 3 described above, even when the distance-measuring pupil distance d differs depending on the imaging lens 202, pupil-splitting phase-difference focus detection can be appropriately performed at positions corresponding to the focus areas 102 and 103 in the peripheral part 500 of region 212a.

[0112] (Modification 4) <Example of discretely providing dedicated pixels> In the above embodiments, examples were described in which the dedicated pixels 410 are arranged continuously in the horizontal direction, or the dedicated pixels 420 are arranged continuously in the vertical direction, as illustrated in Figures 7(a) and 9(a). However, the dedicated pixels 410 and 420 do not necessarily have to be continuous. Figure 18 illustrates a first example in which the dedicated pixels 410 are arranged discretely. In Figure 18, the dedicated pixels 410 are arranged on the GB horizontal line in which the green (G) and blue (B) of the color filter 310 appear alternately, and the dedicated pixels 410 are arranged at predetermined intervals (for example, every 4 pixels).

[0113] The dedicated pixels 410 do not necessarily have to be placed on the same horizontal line. Figure 19 illustrates a second example in which the dedicated pixels 410 are arranged discretely. In Figure 19, the dedicated pixels 410 are placed on different GB horizontal lines. When the dedicated pixels 410 are placed on different horizontal lines, phase-detection autofocus suitable for when the image structure is oblique can be performed.

[0114] Figure 20 illustrates a third example in which dedicated pixels 410D are discretely arranged. In Figure 20, the light-shielding members Ba and Bb of the dedicated pixels 410D are arranged on different GB horizontal lines. That is, the dedicated pixels 410D are arranged between different horizontal lines. When the dedicated pixels 410D are arranged between different horizontal lines, phase-detection autofocus suitable for cases where the image structure is oblique can be performed.

[0115] According to Modification 4, in the peripheral portion 500, dedicated pixels 410 (410D) for pupil division are arranged at predetermined intervals among the array of normal pixels 300. Generally, at the location of the dedicated pixels 410 (410D) equipped with the light-shielding member B, interpolation processing is performed using the image signals converted photoelectrically by the surrounding normal pixels 300.

[0116] As described above, the interpolation process calculates the image signal for each pixel position constituting the dedicated pixel 410 (410D) using the readout signals from the two photoelectric conversion units S1 and S2 of the surrounding normal pixels 300. By arranging the dedicated pixels 410 (410D) discretely, the burden of the interpolation process can be reduced compared to when the dedicated pixels 410 (410D) are arranged continuously.

[0117] In the modified example 4, the dedicated pixels 410 (410D) located on both the left and right sides of the light-shielding member B were used as an example to explain how the ratio of the light beam divided among them differs. However, the same applies to dedicated pixels 420 located on both the top and bottom sides of the light-shielding member B to which the ratio of the light beam divided differs.

[0118] (Variation 5) <Direction in which photoelectric conversion units S1 and S2 are aligned> In the above description, an example was described in which two photoelectric conversion units S1 and S2, such as a normal pixel 300 and a dedicated pixel 410 (420), are arranged horizontally across the entire area 212a of the image sensor 212. Alternatively, the two photoelectric conversion units S1 and S2, such as a normal pixel 300 and a dedicated pixel 410 (420), may be arranged vertically across the entire area 212a. Furthermore, pixels 300 and dedicated pixels 410 (420) with two photoelectric conversion units S1 and S2 arranged horizontally, and pixels 300 with two photoelectric conversion units S1 and S2 arranged vertically, may be mixed in region 212a.

[0119] (Experimental variation 6) <Configuration of the photoelectric conversion unit in a dedicated pixel> In the above embodiment, an example was described in which two photoelectric conversion units S1 and S2 are arranged in a dedicated pixel 410 (420). Alternatively, a configuration may be used in which one photoelectric conversion unit S3 is arranged in one dedicated pixel 410 (420).

[0120] Figure 21 illustrates a dedicated pixel 410 in modified example 6. Compared to Figure 7(b) illustrating the above embodiment, the dedicated pixel 410 differs in that it is provided with one photoelectric conversion unit S3 instead of the two photoelectric conversion units S1 and S2. The light-receiving area of ​​the photoelectric conversion unit S3 is approximately equal to the sum of the light-receiving areas of the two photoelectric conversion units S1 and S2.

[0121] The light-shielding member B in Figure 21 is provided at a ratio of one member for every two pixels 410, which is the same as in the case of Figure 7(b). The light-shielding member B blocks the light beam incident on the photoelectric conversion unit S3 by covering a portion of the photoelectric conversion unit S3. As a result, the ratio of the light beam divided between the dedicated pixels 410 located on both the left and right sides of the light-shielding member B is different.

[0122] For the dedicated pixels 420, a configuration in which one photoelectric conversion unit S3 is placed for each pixel is also possible. Figure 22 is a diagram illustrating a dedicated pixel 420 in modified example 6. Compared to Figure 9(b) illustrating the above embodiment, the dedicated pixel 420 differs in that it is provided with one photoelectric conversion unit S3 instead of two photoelectric conversion units S1 and S2. The light-receiving area of ​​the photoelectric conversion unit S3 is approximately equal to the sum of the light-receiving areas of the two photoelectric conversion units S1 and S2.

[0123] The light-shielding member B in Figure 22 is provided at a ratio of one member for every two pixels 420, which is the same as in the case of Figure 9(b). The light-shielding member B causes the ratio of the light beam to be divided into dedicated pixels 420 located on both the upper and lower sides of the light-shielding member B to be different.

[0124] Even when dedicated pixels 410 and 420 are configured as in the modified example 6 described above, it is possible to make the ratio of the light beam divided among the pixels constituting these dedicated pixels 410 and 420 different, so that pupil-splitting phase-difference focus detection can be properly performed at positions corresponding to the focus areas 102 to 105 in the peripheral part 500 of region 212a.

[0125] In the above explanation, a digital camera 201 equipped with an image sensor 212 was used as an example, but the image sensor 212 may also be mounted on electronic devices such as mobile phones, smartphones, and wearable devices. Figure 23(a) is an example of the front view of a smartphone 50, and Figure 23(b) is an example of the back view of a smartphone 50. A camera unit 512 equipped with an image sensor 212 is provided, for example, on the back of the smartphone 50.

[0126] Figure 24 illustrates the external appearance of the glasses-type wearable device 60. A camera unit 612 equipped with an image sensor 212 is provided.

[0127] Although various embodiments and modifications have been described above, the present invention is not limited to these. Other embodiments conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention. [Explanation of symbols]

[0128] 10... Microlenses 20a~20c... Separation light-shielding member 201… Digital camera 202… IM Lens 203...Camera body 206...Lens control device 210... Focusing lens 212…Image sensor 212a...area 214...Body control device 300... pixels 350…Pixels for large defocus 310... Color Filter 400...Central part 410A~C, 420, 430… Dedicated pixels 450... Dedicated pixels for large defocus 410d, 450d...Aperture 500... Peripheral area B, B1, B2, Ba, Bb... Light-shielding materials H...image height S1, S2, S3, S1B, S2B... Photoelectric conversion unit

Claims

[Claim 1] The first microlens into which light is incident, The second microlens into which light is incident, A first photoelectric conversion region that converts light from the first microlens into an electric charge, A second photoelectric conversion region that converts light from the second microlens into electric charge, A light-shielding member, wherein the light-receiving area of ​​the first photoelectric conversion region that receives light from the first microlens and the light-receiving area of ​​the second photoelectric conversion region that receives light from the second microlens are arranged to have different light-receiving areas. Equipped with, The first photoelectric conversion region is, A first photoelectric conversion unit that converts light into electric charge, A second photoelectric conversion unit that converts light into electric charge and It has, The aforementioned second photoelectric conversion region is A third photoelectric conversion unit that converts light into electric charge, A fourth photoelectric conversion unit that converts light into electric charge and Having, Image sensor.

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