JP2018182397A - Image pickup device and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup device capable of suppressing an image quality deterioration of an image.SOLUTION: An image pickup device includes: a first pixel that includes a first filter having a first spectral characteristic, and outputs a signal on the basis of an electric charge generated by performing a photoelectric conversion of light passed through the first filter; a second pixel that includes a second filter arranged adjacent to the first pixel and including a second spectral characteristic, and outputs a signal on the basis of electric charge generated by performing a photoelectric conversion of light passed through the second filter; and a third pixel that includes a third filter having a third spectral characteristic, includes a fourth filter having a fourth spectral characteristic transmitting the light of at least a part of a wavelength of the wavelength of the light transmitted through the second filter, between the first filter of the first pixel and the third filter arranged adjacently, and outputs a signal for performing a focal detection on the basis of the electric charge generated by performing a photoelectric conversion of light passed through the third filter.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an imaging device and an imaging device.

  There is known an imaging device in which a partition is provided between two color filters provided adjacent to each other (Patent Document 1). In the imaging device of Patent Document 1, a partition wall portion is provided between a white color filter and a color filter other than white (red, green, blue). However, in this imaging device, focus detection pixels are not considered.

JP, 2016-9813, A

According to a first aspect of the present invention, an imaging device includes a first filter having a first spectral characteristic, and a signal based on a charge generated by photoelectric conversion of light transmitted through the first filter is obtained. It has the 1st pixel to output, and the 2nd filter which has the 2nd spectral characteristic arranged next to the 1st pixel, and photoelectrically converts and generates the light which penetrated the 2nd filter And a third filter having a third spectral characteristic, and the first filter and the third filter of the first pixel disposed next to each other. And a fourth filter having a fourth spectral characteristic that transmits light of at least a portion of the wavelength of light transmitted through the second filter, and the third filter transmits the third filter. To perform focus detection based on the charge generated by photoelectric conversion of And a third pixel that outputs a signal.
According to a second aspect of the present invention, an imaging device comprises: an imaging element according to the first aspect; a signal output from the first pixel of the imaging element for capturing an image by an optical system having a focusing lens; An image generated by the optical system is generated on the image pickup device based on an image generation unit that generates image data based on signals output from two pixels and a signal output from the third pixel of the image pickup device And a control unit that controls the position of the focus lens to focus.

FIG. 1 is a diagram illustrating an example of a configuration of an imaging device according to a first embodiment. It is a figure which shows the example of arrangement | positioning of the pixel of the image pick-up element which concerns on 1st Embodiment. It is a figure for demonstrating the signal produced | generated by the image pick-up element which concerns on 1st Embodiment. It is a top view of an image sensor concerning a 1st embodiment. It is a figure which shows the structural example of the pixel of the image pick-up element which concerns on 1st Embodiment. It is a figure which shows the other structural example of the pixel of the image pick-up element which concerns on 1st Embodiment. It is a figure which shows the other structural example of the pixel of the image pick-up element which concerns on 1st Embodiment. It is a figure which shows the structural example of the pixel of the image pick-up element which concerns on modification 1. FIG. FIG. 13 is a diagram for describing a configuration example of pixels of an imaging element according to a modification example 2;

First Embodiment
FIG. 1 is a view showing a configuration example of an electronic camera 1 (hereinafter, referred to as a camera 1) which is an example of an imaging device according to the first embodiment. The camera 1 is composed of a camera body 2 and an interchangeable lens 3. The interchangeable lens 3 is detachably mounted to the camera body 2 via a mount (not shown). When the interchangeable lens 3 is attached to the camera body 2, the connection portion 202 on the camera body 2 side and the connection portion 302 on the interchangeable lens 3 side are connected, and communication between the camera body 2 and the interchangeable lens 3 becomes possible.

  In FIG. 1, light from the subject is incident in the Z-axis plus direction in FIG. 1. Further, as shown in the coordinate axes, the front side of the drawing sheet orthogonal to the Z axis is taken as an X axis plus direction, and the downward direction orthogonal to the Z axis and the X axis is taken as a Y axis plus direction. In the following several figures, coordinate axes are displayed so that the orientation of each figure can be known with reference to the coordinate axes in FIG.

  The interchangeable lens 3 includes an imaging optical system (imaging optical system) 31, a lens control unit 32, and a lens memory 33. The imaging optical system 31 includes a plurality of lenses including a focusing lens (focusing lens) and an aperture, and forms an object image on an imaging surface of the imaging element 22 of the camera body 2.

  The lens control unit 32 adjusts the focal position of the imaging optical system 31 by advancing and retracting the focusing lens in the direction of the optical axis L 1 based on the signal output from the body control unit 21 of the camera body 2. The signal output from the body control unit 21 includes information indicating the movement direction, the movement amount, the movement speed, and the like of the focusing lens. The lens control unit 32 also controls the aperture diameter of the aperture based on the signal output from the body control unit 21 of the camera body 2.

  The lens memory 33 is configured of, for example, a non-volatile storage medium or the like. The lens memory 33 stores information related to the interchangeable lens 3 as lens information. The lens information includes, for example, information on the position of the exit pupil of the imaging optical system 31. Writing of lens information to the lens memory 33 and reading of lens information from the lens memory 33 are performed by the lens control unit 32.

  The camera body 2 includes a body control unit 21, an imaging device 22, a memory 23, a display unit 24, and an operation unit 25. The body control unit 21 includes a CPU, a ROM, a RAM, and the like, and controls each unit of the camera 1 based on a control program. The body control unit 21 also performs various signal processing.

  The imaging device 22 is, for example, a CMOS image sensor or a CCD image sensor. The imaging element 22 receives the light flux that has passed through the exit pupil of the imaging optical system 31, and captures an object image formed by the imaging optical system 31. In the imaging element 22, a plurality of pixels having photoelectric conversion units are arranged in a two-dimensional manner (for example, in the row direction and the column direction). The photoelectric conversion unit is configured of, for example, a photodiode (PD). The imaging device 22 photoelectrically converts incident light in a photoelectric conversion unit to generate a charge, and outputs a signal based on the generated charge to the body control unit 21. The image sensor 22 will be described below with reference to FIGS. 2 and 3.

  FIG. 2 is a view showing an arrangement example of pixels of the imaging device 22 according to the first embodiment. In the imaging element 22, pixels are arranged in a two-dimensional form (row direction (± X direction) and column direction (± Y direction)). The example shown in FIG. 2 illustrates a total of 48 pixels of 6 rows and 8 columns. The number and arrangement of the pixels arranged in the imaging device 22 are not limited to the illustrated example. The imaging device 22 is provided with, for example, millions to hundreds of millions or more of pixels.

  The imaging device 22 includes a plurality of imaging pixels 12 and focus detection pixels 11 and 13. The imaging pixel 12 is provided with one of three color filters (color filters) 51 having different spectral characteristics of, for example, R (red), G (green), and B (blue). The G color filter transmits light in a wavelength range shorter than that of the R color filter. The B color filter transmits light in a wavelength range shorter than that of the G color filter. The R color filter 51 mainly transmits light in the red wavelength range, the G color filter 51 mainly transmits light in the green wavelength range, and the B color filter 51 mainly transmits light in the blue wavelength range Through. Thus, the pixels have different spectral characteristics depending on the color filters 51 arranged. The R pixel, the G pixel and the B pixel are arranged according to the Bayer arrangement.

  The focus detection pixels 11 and 13 are disposed in place of a part of the R, G, and B imaging pixels 12 arranged in the Bayer arrangement as described above. The focus detection pixels 11 and 13 are provided with a color filter 51, a color filter 52, and a light shielding film 43. The position of the light shielding portion 43 of the focus detection pixel 11 is different from that of the focus detection pixel 13. In the focus detection pixel 11 and the focus detection pixel 13, for example, a W (white) color filter that transmits light in the wavelength range of R, G, and B is disposed as the color filter 51. In addition, the color filter 52 is provided in place of a part of the color filter 51. Although the details will be described later, the color filter 52 is a color filter for crosstalk light limitation that limits (controls) the wavelength range of light (referred to as crosstalk light) leaking from the focus detection pixels 11 and 13 to the next imaging pixel 12 (Filter unit). In the present embodiment, the crosstalk light limiting color filter 52 is provided so as to surround four sides of the color filter 51.

  The image sensor 22 includes pixels having R color filters 51 (hereinafter referred to as R pixels) 12 and pixels having G color filters 51 (hereinafter referred to as G pixels) 12 alternately arranged in the row direction. There is one pixel group 401. The imaging device 22 also has a second pixel group 402 in which pixels (hereinafter referred to as B pixels) 12 having the G pixels 12 and B color filters 51 are alternately arranged in the row direction. Furthermore, the imaging device 22 includes a third pixel group 403 in which the G pixels 12 and the focus detection pixels 11 and 13 are arranged in the row direction. The third pixel group 403 may not have both of the focus detection pixels 11 and 13. For example, the pixel group 402 may have the G pixel 12 and the focus detection pixel 11, and the pixel group 403 may have the G pixel 12 and the focus detection pixel 13. Further, the third pixel group 403 has the focus detection pixels 11 and 13 at the position corresponding to the B pixel 12 of the pixel group 402, but a part of the position corresponding to the B pixel 12 of the pixel group 402 The focus detection pixels 11 and 13 may be included. For example, the third pixel group 403 may include at least one of the focus detection pixels 11 and 13, the G pixel 12, and the B pixel 12.

  Each pixel receives light incident through the imaging optical system 31 and generates a signal according to the amount of light received. Although details will be described later, the imaging pixel 12 outputs a signal for the image data generation unit 21a described later to generate image data, that is, an imaging signal. The focus detection pixels 11 and 13 output signals for the focus detection unit 21b described later to calculate the defocus amount, that is, first and second focus detection signals.

  FIG. 3 is a diagram for explaining a signal generated by the imaging device 22 according to the first embodiment. FIG. 3 shows one imaging pixel 12, one focus detection pixel 11, and one focus detection pixel 13 among the pixels provided in the imaging device 22.

  The imaging pixel 12 includes a microlens 44, a color filter 51, and a photoelectric conversion unit 42 that receives a light flux transmitted through the microlens 44 and the color filter 51. The focus detection pixels 11 and 13 have a micro lens 44, a color filter 51, and a color filter 52 for limiting crosstalk light. Further, in the focus detection pixels 11 and 13, the light blocking portion 43 for blocking a part of the light flux transmitted through the micro lens 44 and the color filter 51, and the other part of the light flux transmitted through the micro lens 44 and the color filter 51 And a photoelectric conversion unit 42. The photoelectric conversion unit 42 of the focus detection pixels 11 and 13 photoelectrically converts a light flux which is not blocked by the light blocking section 43 among the light fluxes transmitted through the microlens 44 and the color filter 51.

  The light shielding portion 43 of the focus detection pixel 11 is disposed to correspond to the area of the substantially left half of the photoelectric conversion portion 42 (the negative X direction side of the photoelectric conversion portion 42). The light shielding portion 43 of the focus detection pixel 11 is located on the X axis negative direction side with respect to the center of the photoelectric conversion portion 42 of the focus detection pixel 11 in the plane (XY plane) intersecting the light incident direction (Z axis negative direction). At least a part is arranged in the area. Further, the area 46 of the focus detection pixel 11 is an area corresponding to the area of the substantially right half of the photoelectric conversion unit 42 (the side in the plus X direction of the photoelectric conversion unit 42). The area 46 of the focus detection pixel 11 is an area on the X axis plus direction side with respect to the center of the photoelectric conversion unit 42 of the focus detection pixel 11 in a plane (XY plane) intersecting the light incident direction (Z axis minus direction). Is an area in which at least a part is arranged.

  On the other hand, the light shielding portion 43 of the focus detection pixel 13 is disposed to correspond to the substantially right half region of the photoelectric conversion portion 42. The light shielding portion 43 of the focus detection pixel 13 is on the X axis plus direction side with respect to the center of the photoelectric conversion portion 42 of the focus detection pixel 13 in a plane (XY plane) intersecting with the light incident direction (Z axis minus direction). At least a part is arranged in the area. Further, the area 46 of the focus detection pixel 13 is an area corresponding to the area on the almost left half of the photoelectric conversion unit 42. The area 46 of the focus detection pixel 13 is an area on the X axis minus direction side with respect to the center of the photoelectric conversion unit 42 of the focus detection pixel 13 in a plane (XY plane) intersecting the light incident direction (Z axis minus direction). Is an area in which at least a part is arranged.

  The micro lens 44 of each pixel condenses the light incident from the upper side in FIG. 2 through the imaging optical system 31. The first light beam 61 and the second light beam 62 which have passed through the first pupil region and the second pupil region of the pupil of the imaging optical system 31 pass through the microlens 44. The optical power of the micro lens 44 is determined so that the position of the light shielding portion 43 of the focus detection pixels 11 and 13 and the first pupil region and the second pupil region of the pupil of the imaging optical system 31 become conjugate with each other. There is.

  In the focus detection pixel 11, of the light transmitted through the microlens 44, the second light beam 62 which has passed through the second pupil region is blocked by the light blocking portion 43 after passing through the color filter 51. Further, in the focus detection pixel 11, among the light transmitted through the micro lens 44, the first light flux 61 which has passed through the first pupil region passes through the color filter 51 and the region 46 and is incident on the photoelectric conversion unit 42. . The area 46 of the focus detection pixel 11 functions as an opening that allows the first light beam 61 having passed through the microlens 44 and the color filter 51 to be incident on the photoelectric conversion unit 42. The photoelectric conversion unit 42 of the focus detection pixel 11 photoelectrically converts the first light beam 61 incident on the photoelectric conversion unit 42 to generate an electric charge.

  On the other hand, in the focus detection pixel 13, of the light transmitted through the microlens 44, the first light flux 61 that has passed through the first pupil region is blocked by the light blocking portion 43 after passing through the color filter 51. Further, in the focus detection pixel 13, of the light transmitted through the microlens 44, the second light beam 62 transmitted through the second pupil region is transmitted through the color filter 51 and the region 46 and enters the photoelectric conversion unit 42. . The area 46 of the focus detection pixel 13 functions as an opening that allows the second light beam 62 having passed through the microlens 44 and the color filter 51 to be incident on the photoelectric conversion unit 42. The photoelectric conversion unit 42 of the focus detection pixel 13 photoelectrically converts the second light beam 62 incident on the photoelectric conversion unit 42 to generate an electric charge.

  As described above, the focus detection pixels 11 and 13 are configured to receive light passing through different areas of the pupil of the imaging optical system 31, and perform pupil division. The focus detection pixel 11 outputs a first focus detection signal based on the charge obtained by photoelectrically converting the first light flux 61 that has passed through the first pupil region. The focus detection pixel 13 outputs a second focus detection signal based on the charge obtained by photoelectrically converting the second light beam 62 which has passed through the second pupil region.

  In the imaging pixel 12, the first and second light beams 61 and 62 which have respectively passed through the first and second pupil regions of the pupil of the imaging optical system 31 are photoelectrically converted through the microlens 44 and the color filter 51. Incident to The imaging pixel 12 outputs an imaging signal related to the light flux that has passed through both the first and second pupil regions. That is, the imaging pixel 12 photoelectrically converts light passing through both the first and second pupil regions, and outputs an imaging signal based on the charge generated by photoelectric conversion.

  The imaging element 22 outputs an imaging signal for generating image data and first and second focus detection signals for performing phase difference focus detection with respect to the focus of the imaging optical system 31 to the body control unit 21. . The first and second focus detection signals are, as described above, the first and second light beams by the first and second light beams respectively passing through the first and second regions of the exit pupil of the imaging optical system 31. It is the signal which each photoelectrically converted the image.

  In FIGS. 2 and 3, the focus detection pixels 11 and 13 are arranged in the row direction (X-axis direction), but may be arranged in the column direction (Y-axis direction). When the focus detection pixels 11 and 13 are arranged in the column direction, the light shielding portion 43 of the focus detection pixel 11 is disposed corresponding to one of the upper half and the lower half of the photoelectric conversion unit 42, and the focus detection is performed. The light shielding portion 43 of the pixel 13 is disposed to correspond to the other upper and lower halves of the photoelectric conversion portion 42. For example, at least a part of the light shielding unit 43 of the focus detection pixel 11 is disposed in a region on the Y axis plus direction side with respect to the center of the photoelectric conversion unit 42 of the focus detection pixel 11. At least a part of the light shielding portion 43 of the focus detection pixel 13 is disposed in a region on the Y axis minus direction side with respect to the center of the photoelectric conversion portion 42 of the focus detection pixel 13.

  In FIG. 1, the memory 23 is, for example, a recording medium such as a memory card. Image data and the like are recorded in the memory 23. Writing of data to the memory 23 and reading of data from the memory 23 are performed by the body control unit 21. The display unit 24 displays an image based on image data, information related to shooting such as shutter speed and aperture value, and a menu screen. The operation unit 25 includes various setting switches such as a release button and a power switch, and outputs an operation signal corresponding to each operation to the body control unit 21.

  The body control unit 21 includes an image data generation unit 21 a and a focus detection unit 21 b. The image data generation unit 21 a performs various types of image processing on the imaging signal output from the imaging element 22 to generate image data. The image processing includes, for example, known image processing such as tone conversion processing, color interpolation processing, and edge enhancement processing.

  The focus detection unit 21 b performs focus detection processing necessary for automatic focusing (AF) of the imaging optical system 31. Specifically, the focus detection unit 21 b detects the in-focus position of the focusing lens (focus lens) for focusing the image by the imaging optical system 31 on the imaging surface of the imaging device 22. The focus detection unit 21 b uses the focus detection signal output from the imaging device 22 to calculate the defocus amount by the pupil division type phase difference detection method. More specifically, the focus detection unit 21b performs correlation calculation to obtain the in-focus position based on the first and second focus detection signals. The focus detection unit 21b calculates the shift amount between the image by the first light beam 61 passing through the first pupil region and the image by the second light beam 62 passing through the second pupil region by the correlation calculation, The defocus amount is calculated based on the image shift amount. The focus detection unit 21b calculates the movement amount of the focusing lens to the in-focus position based on the calculated defocus amount.

  The focus detection unit 21b determines whether the defocus amount is within the allowable value. When the defocus amount is within the allowable value, the focus detection unit 21b determines that the in-focus state is achieved. On the other hand, when the defocus amount exceeds the allowable value, the focus detection unit 21b determines that the lens is not in focus, and sends the amount of movement of the focusing lens and the lens movement instruction to the lens control unit 32 of the interchangeable lens 3. Send. The lens control unit 32 that has received the instruction from the focus detection unit 21b moves the focusing lens according to the movement amount, whereby focusing is automatically performed.

  FIG. 4 is a plan view of the imaging device 22 according to the first embodiment. The imaging element 22 has a pixel area (imaging area) 100 in which pixels are arranged in a matrix. That is, in the pixel area 100, as shown in FIG. 3, a plurality of pixels including the imaging pixel 12 and the focus detection pixels 11 and 12 are two-dimensionally arranged. Outside the pixel area, peripheral circuits (analog-to-digital converter etc.) that process signals from the pixels are arranged. The central region of the image sensor 22, that is, the central region 101 of the pixel region 100 is located on the optical axis L 1 of the interchangeable lens 3.

  An area 102 shown in FIG. 4 is an area located at the left end of the pixel area 100, and an area 103 is an area located at the right end of the pixel area 100. The area 102 and the area 103 are areas where the distance from the center of the pixel area 100 (the distance from the optical axis L1) is long, that is, an area where the image height is high. Hereinafter, the pixel structure of the image sensor 22 according to the present embodiment will be described in more detail by taking the pixels disposed in each of the central area 101, the left end area 102, and the right end area 103 as an example. In particular, the operation of the color light filter 52 for limiting crosstalk light will be described in detail with reference to FIGS.

  FIG. 5 is a view showing a configuration example of pixels of the left end region 102 of the imaging device 22 according to the first embodiment. In FIG. 5A, one focus detection pixel 11 (W pixel) of the pixel group 403 (see FIG. 3) disposed in the left end area 102 and the one disposed adjacent to the focus detection pixel 11 It shows one imaging pixel 12 (G pixel). 5B shows one imaging pixel 12 (B pixel) of the pixel group 402 (see FIG. 3) disposed in the left end region 102 and one imaging that is disposed adjacent to the imaging pixel 12 The pixel 12 (G pixel) is shown.

  The focus detection pixel 11 and the imaging pixel 12 are provided with a photoelectric conversion unit 42, a micro lens 44, an inter-pixel light shielding unit 47, and a color filter 51, respectively. The focus detection pixel 11 is further provided with a light shielding portion 43 and a color filter 52 for limiting crosstalk light. As shown in FIGS. 5A and 5B, the focus detection pixels 11 in the left end region 102 and the microlenses 44 of each of the imaging pixels 12 are pixels with respect to the rest of the focus detection pixels 11 and the remainder of the imaging pixels 12. It is disposed to be shifted to the center side (X-axis plus direction side) of the region 100. Thus, the amount of light incident on the photoelectric conversion unit 42 via the imaging optical system 31 of the camera 1 can be increased.

  In the image pickup device 22, for example, as the pixels are arranged apart from the center of the pixel area 100, the microlenses 44 of the pixels are arranged to be shifted to the center side. The inter-pixel light shielding unit 47 is provided between the color filter 51 and the photoelectric conversion unit 42 and at the boundary between adjacent pixels, and suppresses light leakage to the adjacent pixels.

  In the focus detection pixels 11 and the imaging pixels 12 of the pixel group 403 illustrated in FIG. 5A, a color filter of W and a color filter of G are provided as the color filters 51. Further, in the two imaging pixels 12 of the pixel group 402 shown in FIG. 5B, a color filter of B and a color filter of G are provided as the color filters 51, respectively.

  In the focus detection pixel 11, a color filter 52 for limiting crosstalk light is provided in place of the outer peripheral portion of the W color filter 51. The color filter 52 is also an intervening portion 52 provided between the W color filter 51 of the focus detection pixel 11 and the G color filter 51 of the imaging pixel 12 next to the focus detection pixel 11. In the present embodiment, as shown in FIG. 3, in the focus detection pixel 11, the color filter 52 is disposed so as to surround the W color filter 51. Similarly, in the focus detection pixel 13, the color filter 52 is disposed so as to surround the W color filter 51.

  The color filter 52 is a filter having a spectral characteristic that transmits light of at least a part of the wavelength of light transmitted through the color filter disposed in the imaging pixel 12 replaced with the focus detection pixels 11 and 13. That is, the spectral characteristics of the color filter 52 of the focus detection pixels 11 and 13 may be partially the same as the spectral characteristics of the color filter 51 of the imaging pixel 12. In the imaging device 22 according to the present embodiment, a color filter of the same color as the imaging pixel 12 replaced with the focus detection pixels 11 and 13 is disposed as the color filter 52. In the example of the pixel arrangement shown in FIG. 2 and FIG. 5, since the focus detection pixels 11 and 13 are substituted for the B pixel 12 of the pixels arranged in the Bayer arrangement, the color filter 52 Become. That is, in the present embodiment, the color filter 52 has the spectral characteristic of B.

  Next, color mixing that occurs between adjacent pixels in the image pickup device 22, that is, crosstalk will be described. Color mixing occurs when a luminous flux incident on a pixel enters a pixel in the vicinity of that pixel.

  In the camera 1, abnormal light (ghost light) is generated due to the light passing through the imaging optical system 31 being reflected by the inside of the casing of the camera body 2 or the micro lens 44 of the imaging device 22. Therefore, light having a large incident angle (for example, light having an incident angle of 40 ° to 60 °) may be incident on the microlens 44 of each pixel. When ghost light occurs, light inclined with respect to the optical axis of the microlens 44 which each has is incident on the imaging pixel 12 and the focus detection pixels 11 and 13. In this case, in the image sensor 22, a part of the light transmitted through the microlens 44 of the pixel and the color filter may leak as crosstalk light to the photoelectric conversion unit 42 of the peripheral pixel of the pixel. In the following description, although the influence of crosstalk light due to ghost light is described as a representative of incident light having a large incident angle with respect to the micro lens 44, the explanation regarding ghost light applies to various incident light having a large incident angle. This applies to the influence of the crosstalk light caused.

  First, the influence of crosstalk light between the imaging pixels 12, specifically, crosstalk light from the B pixel to the G pixel will be described. In FIG. 5B, a broken line 71 schematically indicates ghost light passing through the color filter 51 of the imaging pixel (B pixel) 12 and entering the photoelectric conversion unit 42 of the imaging pixel (G pixel) 12 next to it. Is represented in. The ghost light enters the imaging pixel (B pixel) 12 obliquely with respect to the optical axis of the imaging pixel (B pixel) 12 microlens 44. The ghost light passes through the micro lens 44 and the color filter 51 of the imaging pixel (B pixel) 12 and is incident on the photoelectric conversion unit 42 of the imaging pixel (G pixel) 12 next to it. Part of the obliquely incident ghost light 71 passes through the B color filter 51 of the B pixel 12. The light in the wavelength region of B transmitted through the B color filter 51 enters the adjacent G pixel 12 without being blocked by the inter-pixel light shielding portion 47. Therefore, in the pixel group 402, the photoelectric conversion unit 42 of the G pixel 12 adds the light transmitted through the G color filter 51 of the G pixel 12 to the charge generated by photoelectric conversion, and the adjacent B pixel is generated. The light transmitted through the 12 B color filters 51 is photoelectrically converted to generate electric charges. As a result, in the G pixel 12 of the pixel group 402, a signal component of light in the B wavelength range is mixed.

  Next, the influence of crosstalk light from the focus detection pixel 11 to the imaging pixel 12 will be described. The ghost light in FIG. 5A is incident on the focus detection pixel 11 obliquely to the optical axis of the micro lens 44 of the focus detection pixel 11. The ghost light passes through the micro lens 44 and the color filter 51 of the focus detection pixel 11 and enters the photoelectric conversion unit 42 of the image pickup pixel (G pixel) 12 next to the micro light. Part of the ghost light 71 in FIG. 5A passes through the B color filter 52 of the focus detection pixel 11. The light in the wavelength region of B transmitted through the B color filter 52 enters the adjacent G pixel 12 without being blocked by the inter-pixel light shielding portion 47. The ghost light 71 transmitted through the W color filter 51 of the focus detection pixel 11 is blocked by the inter-pixel light shielding portion 47 and does not enter the adjacent G pixel 12. As a result, crosstalk light in the wavelength region of B transmitted through the color filter 52 of the adjacent focus detection pixel 11 is incident on the G pixel 12 of the pixel group 403 in FIG. 5A.

  Although details will be described later, if the focus detection pixels 11 and 13 do not have the color filter 52, the wavelength range of light leaking from the focus detection pixels 11 and 13 to the next imaging pixel 12 and the imaging pixel 12 to the next imaging pixel 12 The wavelength range of the leaking light will be different. For this reason, a difference arises in the output of the imaging pixel (G pixel) 12 with the focus detection pixel 11 next to the imaging pixel (G pixel) 12 with the imaging pixel (B pixel) 12 next to it. Therefore, when the color filter 52 is not provided, the image quality of the image generated using the imaging signal from the imaging pixel 12 is degraded.

  On the other hand, in the present embodiment, both the imaging pixel (G pixel) 12 adjacent to the focus detection pixel 11 and the imaging pixel (G pixel) 12 adjacent to the B pixel are B caused by ghost light or the like. Crosstalk light in the wavelength range of Therefore, the imaging pixel (G pixel) 12 adjacent to the focus detection pixel 11 and the imaging pixel (G pixel) 12 adjacent to the B pixel located in the vicinity of the focus detection pixel 11 have substantially the same wavelength of B. There is almost no difference in the outputs of both imaging pixels (G pixels) 12 due to the influence of crosstalk light in the region. Therefore, a sense of discomfort does not occur in an image based on imaging signals from both imaging pixels (G pixels) 12.

  As described above, in the present embodiment, the wavelength range of light leaking to the imaging pixel 12 is the pixel group 402 in which the focus detection pixels 11 and 13 are not disposed and the pixel group 403 in which the focus detection pixels 11 and 13 are disposed. Crosstalk light limiting color filters 52 are arranged to be equal.

  The thickness (height of the color filter 52 in the Z-axis direction in FIG. 5A) h of the color filter 52 is made substantially the same thickness as the color filter 51 of B of the imaging pixel 12 of the pixel group 402. For example, when the thickness of the color filter 51 of the focus detection pixels 11 and 13 is different from the thickness of the color filter 51 of the imaging pixel 12, the thickness of the color filter 52 is substantially the same as that of the color filter 51 of the imaging pixel 12. Made the same thickness. Furthermore, the color filter 52 is formed of the same material as the B color filter of the imaging pixel 12. Accordingly, the wavelength range and the light amount of light leaking to the imaging pixel 12 are made approximately the same between the pixel group 402 in which the focus detection pixels 11 and 13 are not disposed and the pixel group 403 in which the focus detection pixels 11 and 13 are disposed. Can. In addition, the material which comprises the color filter 52 is not restricted to the same material as the color filter of B, The light of the wavelength of at least one part of the wavelength of the light which permeate | transmits the color filter arrange | positioned at imaging pixel 12 is transmitted It is sufficient if it is a material having the following spectral characteristics.

  The thicknesses of all the color filters of the color filter 51 disposed in the imaging pixel 12 and the color filters 51 51 disposed in the focus detection pixels 11 and 13 are preferably substantially the same. Thereby, in the imaging pixel 12 next to the focus detection pixels 11 and 13 and the imaging pixel 12 next to the imaging pixel 12, the difference between the wavelength range and the light amount of light leaking to the imaging pixel 12 can be further reduced.

  The color filters 52 of the focus detection pixels 11 and 13 are formed with a predetermined width so as not to transmit light other than a specific wavelength range (the wavelength range of B in the above example). In this case, the width of the W color filter 51 of the focus detection pixels 11 and 13 decreases accordingly, and the light reception amount of the photoelectric conversion unit 42 of the focus detection pixels 11 and 13 decreases. Therefore, assuming that the pixel pitch (pixel spacing) is L as shown in FIG. 5A, the width (width in the X-axis direction) W of the color filter 52 is W / L = 5% to 20%. It is desirable to be set as By setting the width W of the color filter 52 in this manner, the light reception amount of the focus detection pixels 11 and 13 can be secured, and the adjacent pixels of the focus detection pixels 11 and 13 and the adjacent pixels of the imaging pixel 12 can be obtained. The difference in the amount of light leaked to the pixel of FIG.

  In addition, since the incident angles of ghost light and the like differ according to the position where the focus detection pixels 11 and 13 are disposed, color filters of different widths are respectively provided to the plurality of focus detection pixels 11 and 13 disposed in the imaging device 22. 52 may be arranged. For example, the width of the color filter 52 in the direction (X-axis direction) intersecting the direction in which light is incident may be larger as the distance from the center of the imaging device 22 (the center of the pixel area 100).

  In the following, the difference between the wavelength range of light leaking from the focus detection pixels 11 and 13 to the adjacent imaging pixel 12 and the wavelength range of light leaking from the imaging pixel 12 to the adjacent imaging pixel 12 is reduced, Description will be made in comparison with a comparative example. In the comparative example, when the focus detection pixel 11 of FIG. 5A does not have the color filter 52 for limiting crosstalk light, that is, the W color filter 51 is disposed at the position of the B color filter 52. is there. In this case, part of the ghost light incident on the micro lens 44 of the focus detection pixel 11 passes through the W color filter 51 and is incident on the photoelectric conversion unit 42 of the G pixel 12 adjacent thereto. The W color filter 51 has a spectral characteristic of transmitting light in the R, G, and B wavelength regions, so that light other than B is incident on light incident on the photoelectric conversion unit 42 of the G pixel 12 of the pixel group 403. The light of the area is also included.

  On the other hand, in the G pixel 12 of the pixel group 402 in which the focus detection pixels 11 and 13 are not disposed, light in the wavelength range of B from the adjacent B pixel 12 is incident as described above. Therefore, in the case of the comparative example, the wavelength range of light leaking from the focus detection pixels 11 and 13 to the adjacent imaging pixel 12 is different from the wavelength range of light leaking from the imaging pixel 12 to the adjacent imaging pixel 12 . Further, in the case of the comparative example, light in a wavelength range other than B also leaks to the imaging pixel 12, so the light amount of light from the focus detection pixel 11 or 13 to the adjacent imaging pixel 12 due to ghost light etc. The amount of light to the adjacent imaging pixel 12 is more than that. As a result, unnatural coloring occurs in the image generated using the imaging signal from the imaging pixel 12.

  On the other hand, in the focus detection pixels 11 and 13 according to the present embodiment, as described above, by providing the B color filter as the color filter 52 for crosstalk light restriction, light of wavelength bands other than B is adjacent. Leakage to the imaging pixel 12 can be suppressed. For this reason, the difference between the wavelength range and the light amount of light leaking from the focus detection pixels 11 and 13 to the nearby imaging pixel 12 due to ghost light etc. and the wavelength range and the light amount of light leaking from the imaging pixel 12 to the nearby imaging pixel 12 Can be reduced. As a result, it is possible to prevent the occurrence of coloring in an image generated using an imaging signal.

  FIG. 6 is a view showing a configuration example of pixels in the right end region 103 of the imaging device 22 according to the first embodiment. FIG. 6A shows the focus detection pixel 11 of the pixel group 403 and the G imaging pixel 12 disposed adjacent to the focus detection pixel 11. FIG. 6B illustrates the imaging pixel 12 of B in the pixel group 402 and the imaging pixel 12 of G disposed adjacent to the imaging pixel 12 of B. The focus detection pixel 11 in the right end region 103 and the microlens 44 of each of the imaging pixels 12 are arranged to be shifted to the center side (X-axis minus direction side) of the pixel region 100. Thus, the amount of light incident on the photoelectric conversion unit 42 via the imaging optical system 31 of the camera 1 can be increased. Further, in the focus detection pixel 11, the color filter 52 is disposed so as to surround four sides of the color filter 51.

  In the pixel group 402 of FIG. 6B, the ghost light indicated by the broken line 71 passes through the microlenses 44 of the B pixel 12 and the color filter 51 of B and enters the photoelectric conversion unit 42 of the G pixel 12. Therefore, in the G pixel 12 disposed in the pixel group 402 in which the focus detection pixels 11 and 13 are not disposed, light in the wavelength range of B enters from the adjacent B pixel 12. On the other hand, in the pixel group 403 in which the focus detection pixels 11 and 13 of FIG. 6A are arranged, the ghost light indicated by the broken line 71 is the microlens 44 of the focus detection pixel 11 and the color filter 52 (color filter of B). The light is transmitted to the photoelectric conversion unit 42 of the G pixel 12. As described above, also in the right end region 103, the imaging pixel 12 adjacent to the focus detection pixel 11 and the imaging pixel 12 adjacent to the B pixel located in the vicinity of the focus detection pixel 11 have substantially the same B wavelength. Affected by crosstalk light in the For this reason, it can prevent that a sense of incongruity arises in the picture generated using the image pick-up signal of these image pick-up pixels 12. FIG.

  FIG. 7 is a view showing a configuration example of pixels of the central region 101 of the imaging device 22 according to the first embodiment. FIG. 7A shows the focus detection pixel (W pixel) 11 of the pixel group 403 and the G imaging pixel 12 disposed adjacent to the focus detection pixel 11. FIG. 7B illustrates the imaging pixel 12 of B in the pixel group 402 and the imaging pixel 12 of G disposed adjacent to the imaging pixel 12. Also in the focus detection pixels 11 disposed in the central region 101, the color filter 52 is disposed so as to surround four sides of the color filter 51.

  Also in the central region 101, obliquely incident light is generated due to light reflected by the microlens 44 or the like. Therefore, in the focus detection pixels 11 and 13 in the central area 101, the color filter 52 is disposed so as to surround four sides of the color filter 51. Thus, in the central region 101 as well, the imaging pixel 12 adjacent to the focus detection pixel 11 and the imaging pixel 12 adjacent to the B pixel located in the vicinity of the focus detection pixel 11 have substantially the same wavelength range of B Affected by crosstalk light. For this reason, it can prevent that a sense of incongruity arises in the picture generated using the image pick-up signal of these image pick-up pixels 12. FIG.

According to the embodiment described above, the following effects can be obtained.
(1) The imaging device 22 has a first filter (for example, a G color filter) having a first spectral characteristic, and a signal based on charges generated by photoelectric conversion of light transmitted through the first filter. A second filter (for example, a B color filter) having a second spectral characteristic, which is disposed next to the first pixel (imaging pixel) for outputting And a second pixel (imaging pixel) that outputs a signal based on the charge generated by photoelectric conversion of the light transmitted through the second light source, and a third filter (for example, a W color filter) having a third spectral characteristic. Between the first filter and the third filter of the first pixel disposed next to each other, a fourth spectrum transmitting light of at least a part of the wavelength of light transmitted through the second filter A fourth filter having characteristics (eg B color filter The has provided based on a third charge of light transmitted through the filter is generated by photoelectric conversion, and a third pixel outputting a signal for performing focus detection (focus detection pixels), the. Since this arrangement is adopted, the crosstalk between the imaging pixel arranged next to the focus detection pixel and the imaging pixel arranged next to the imaging pixel located in the vicinity of the focus detection pixel is the same wavelength range as each other. Affected by light. For this reason, it is possible to suppress the occurrence of the difference due to the crosstalk light in the pixel signals from both imaging pixels. As a result, it is possible to prevent the image quality from being degraded due to coloring of the image based on the imaging signal from the imaging pixel.

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

(Modification 1)
In the embodiment described above, an example in which the color filter 52 for limiting crosstalk light is disposed in the focus detection pixels 11 and 13 so as to surround the W color filter 51 has been described, but the present invention is not limited thereto. The crosstalk light limiting color filter 52 may be arranged only in the necessary direction. In the focus detection pixels 11 and 13, as shown in FIG. 8A, a color filter 52 for limiting crosstalk light may be disposed only in the row direction (horizontal direction). For example, when crosstalk light from the focus detection pixels 11 and 13 to the left and right imaging pixels 12 is larger than crosstalk light from the focus detection pixels 11 and 13 to the upper and lower imaging pixels 12, as illustrated in FIG. The color filter 52 is disposed as shown in FIG.

  Further, as shown in FIG. 8B, the color filter 52 for limiting crosstalk light may be disposed only on the right side (X-axis plus direction side) of the focus detection pixels 11 and 13. For example, in the focus detection pixels 11 and 13 in the left end region 102 described above, ghost light and the like from the casing of the camera body 2 are obliquely incident from the X axis minus side as shown in FIG. 5A. The color filter 52 may be disposed only on the right side (X-axis plus direction side) of the focus detection pixels 11 and 13. As a result, when light is incident obliquely from the X axis minus side, the wavelength range of crosstalk light from the focus detection pixels 11 and 13 to the right imaging pixel 12 can be limited.

  Further, as shown in FIG. 8C, the color filter 52 for limiting crosstalk light may be disposed only on the left side (X-axis minus direction side) of the focus detection pixels 11 and 13. For example, in the focus detection pixels 11 and 13 in the right end region 103 described above, ghost light or the like from the casing of the camera body 2 is obliquely incident from the X axis plus side as shown in FIG. The color filter 52 for limiting crosstalk light may be disposed only on the left side (X-axis minus direction side) of the focus detection pixels 11 and 13. Thereby, when light is obliquely incident from the X axis plus side, crosstalk light from the focus detection pixels 11 and 13 to the left imaging pixel 12 can be limited.

  As shown in FIG. 8D, the color filter 52 for limiting crosstalk light may be disposed only in the column direction (vertical direction). For example, when crosstalk light from the focus detection pixels 11 and 13 to the upper and lower imaging pixels 12 is larger than crosstalk light from the focus detection pixels 11 and 13 to the left and right imaging pixels 12, FIG. The color filter 52 for crosstalk light limitation is disposed as shown in FIG. The color filter 52 for crosstalk light limitation may be disposed only on the upper side (Y-axis minus direction side) of the focus detection pixels 11 and 13 or the lower side (Y-axis plus direction) of the focus detection pixels 11 and 13. The color filter 52 for limiting crosstalk light may be disposed only on the side).

(Modification 2)
FIG. 9 is a diagram for describing a configuration example of a pixel of an imaging device according to the second modification. The color filter 52 for limiting crosstalk light shown in FIG. 9A has the inside of the focus detection pixels 11 and 13 such that the outer edge thereof is in contact with the boundary 80 between the focus detection pixels 11 and 13 and the imaging pixel 12. Will be placed. That is, the color filter 52 for crosstalk light restriction shown in FIG. 9A is entirely disposed in the area of the focus detection pixels 11 and 13. By providing the crosstalk light limiting color filter 52 in the area of the focus detection pixel in this manner, the crosstalk light limiting color filter 52 does not block incident light to the adjacent imaging pixel 12.

  In FIG. 9B, the color filter 52 for limiting crosstalk light has an inner edge portion in contact with the boundary 80 between the focus detection pixels 11 and 13 and the imaging pixel 12 in the focus detection pixels 11 and 13. It is disposed in the surrounding imaging pixel 12. That is, the color filter 52 for crosstalk light restriction does not exist in the area of the focus detection pixels 11 and 13, and is all disposed in the imaging pixel 12. Therefore, the crosstalk light limiting color filter 52 does not block incident light incident on the focus detection pixels 11 and 13.

  The crosstalk light limiting color filter 52 shown in FIG. 9C is disposed on the boundary 80 between the focus detection pixels 11 and 13 and the imaging pixel 12, that is, is disposed across the boundary 80. In other words, a part of the color filter 52 for limiting crosstalk light is provided in the area of the focus detection pixels 11 and 13, and the remaining part is provided in the area of the imaging pixel 12.

(Modification 3)
In the embodiment described above, the case where the primary color system (RGB) color filter is used for the imaging device 22 has been described, but a complementary color system (CMY) color filter may be used.

(Modification 4)
In the embodiment described above, an example in which the W color filter 51 is disposed in the focus detection pixels 11 and 13 has been described, but the present invention is not limited to this. For example, in the focus detection pixels 11 and 13, as the color filter 51, light of at least a portion of the wavelength of light transmitted through the G color filter and light of at least a portion of light transmitted through the B color filter A filter having spectral characteristics through which the light passes may be arranged. In addition, in the focus detection pixels 11 and 13, as the color filter 51, a color filter that transmits light in the G wavelength band and light in the B wavelength band may be disposed. A G color filter or a Cy (cyan) color filter may be disposed.

(Modification 5)
In the embodiment described above, an example in which a photodiode is used as the photoelectric conversion unit has been described. However, a photoelectric conversion film may be used as the photoelectric conversion unit.

(Modification 6)
In the embodiment described above, an example in which one photoelectric conversion unit is disposed in one pixel has been described, but the configuration of the pixel is not limited to this. The pixel configuration may have two or more photoelectric conversion units per pixel.

(Modification 7)
The image pickup device and the image pickup apparatus described in the above embodiment and modification are applied to a camera, a smartphone, a tablet, a camera built in a PC, an on-vehicle camera, a camera mounted on an unmanned aerial vehicle (drone, radio control machine etc.) It may be done.

  Although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other embodiments considered within the scope of the technical idea of the present invention are also included within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Imaging device, 2 ... Camera body, 3 ... Interchangeable lens, 21 ... Body control part, 21a ... Image data generation part, 21b ... Focus detection part, 22 ... Imaging element, 31 ... Imaging optical system, 42 ... Photoelectric conversion part , 44: micro lens, 43: light shielding part, 51: color filter, 52: color filter

Claims (12)

A first pixel having a first filter having a first spectral characteristic, and outputting a signal based on charges generated by photoelectrically converting light transmitted through the first filter;
It has a second filter having a second spectral characteristic, which is disposed adjacent to the first pixel, and outputs a signal based on charges generated by photoelectrically converting light transmitted through the second filter. A second pixel to be
Light transmitted through the second filter between the first filter and the third filter of the first pixel disposed next to the third filter having the third spectral characteristic A fourth filter having a fourth spectral characteristic that transmits light of at least a portion of the wavelength of the light source, and a focal point based on a charge generated by photoelectric conversion of the light transmitted through the third filter A third pixel that outputs a signal for performing detection;
An imaging device comprising: In the imaging device according to claim 1,
The image pickup device in which the fourth filter has the second spectral characteristic. In the imaging device according to claim 1 or 2,
An imaging element that outputs a signal based on charges generated by photoelectric conversion of light transmitted through at least one of the first filter and the fourth filter; The image pickup device according to any one of claims 1 to 3.
Each of the first pixel and the third pixel has a microlens.
The first pixel is based on a charge generated by photoelectric conversion of light which has been transmitted obliquely through the microlens of the third pixel and obliquely incident on the optical axis of the microlens of the first pixel. Image sensor that outputs a signal. The imaging device according to any one of claims 1 to 4.
The second filter has a first width in a first direction in which light is incident;
An imaging element having a width substantially the same as the first width in the first direction; The imaging device according to any one of claims 1 to 5,
Assuming that the width of the fourth filter in a second direction crossing the light incident direction is W, and the distance between the third pixel and the first pixel adjacent to the third pixel is L, An imaging element in which W / L = 5% to 20% holds. In the imaging device according to claim 6,
Having a plurality of the third pixels,
An imaging element in which the width of the fourth filter in the second direction is different, each of the plurality of third pixels has. In the imaging device according to claim 7,
An imaging device in which the width of the fourth filter in the second direction is larger as the distance from the center of the imaging device is larger. The imaging device according to any one of claims 1 to 8.
The third pixel is surrounded by the four first pixels, and the imaging device includes the fourth filter between the first filter and the third filter of the four first pixels. . The imaging device according to any one of claims 1 to 9.
The third filter transmits the light of at least a portion of the wavelength of light transmitted through the first filter and the light of the wavelength of at least a portion of light transmitted through the second filter. An imaging device having the spectral characteristics of The imaging device according to any one of claims 1 to 10.
The first filter transmits light having a first wavelength,
The second filter transmits light having a second wavelength shorter than the first wavelength,
The image pickup element having the third spectral characteristic in which the third filter transmits the light of the first wavelength and the light of the second wavelength. An imaging device according to any one of claims 1 to 11;
An image generation unit that generates image data based on a signal output from the first pixel of the image pickup element that captures an image by an optical system having a focus lens and a signal output from the second pixel;
A control unit configured to control the position of the focus lens such that an image by the optical system is focused on the imaging device based on a signal output from the third pixel of the imaging device;
An imaging device comprising:

Images