Image pickup element and imaging device

Abstract

To obtain correct exposure for every area of an image.SOLUTION: An image pickup device comprises: a plurality of first pixels for imaging each transmitting light in a first wavelength region and having a first transmission film; a plurality of second pixels for focus detection each transmitting light in a second wavelength region and having a second transmission film; first light shielding parts provided around the first pixels arranged adjacent to the second pixels, of the plurality of first pixels; and second light shielding parts provided around the first pixels not arranged adjacent to the second pixels, of the plurality of first pixels. The area of the first transmission film of the first pixel arranged adjacent to the second pixel is determined according to the width of the first light shielding part. The width of the first light shielding part is larger than the width of the second light shielding part. The area of the first transmission film of the first pixel arranged adjacent to the second pixel is smaller than the area of the first transmission film of the first pixel not arranged adjacent to the second pixel.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] There is known an image plane phase difference detection type image sensor in which some of the imaging pixels arranged on the image sensor are used as focus detection pixels that detect the focus state of an image formed on the image sensor (for example, Patent Document 1). However, there is a problem of stray light caused by the focus detection pixels. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-29674 A Summary of the Invention

[0004] An image sensor according to a first aspect of the present invention includes a plurality of first pixels for imaging having a first transparent film that transmits light in a first wavelength range, a second pixel for focus detection having a second transparent film that transmits light in a second wavelength range, a first light-shielding portion provided around the first pixel that is adjacent to the second pixel among the plurality of first pixels, and a second light-shielding portion provided around the first pixel that is not adjacent to the second pixel among the plurality of first pixels, wherein an area of ​​the first transparent film of the first pixel adjacent to the second pixel is determined by a width of the first light-shielding portion, the width of the first light-shielding portion is wider than the width of the second light-shielding portion, and an area of ​​the first transparent film of the first pixel adjacent to the second pixel is smaller than an area of ​​the first transparent film of the first pixel not adjacent to the second pixel. [Brief description of the drawings]

[0005] [Figure 1] FIG. 1 is a cross-sectional view illustrating a schematic configuration of an imaging device. [Diagram 2] FIG. 2 is a partially enlarged plan view of the imaging element according to the first embodiment, as viewed from the imaging surface side. [Diagram 3]FIG. 2 is a cross-sectional view of the image sensor according to the first embodiment. [Figure 4] 1 is a cross-sectional view of a pixel included in the image sensor according to the first embodiment. [Diagram 5] FIG. 11 is a partially enlarged plan view of an image sensor according to a second embodiment, as viewed from the image pickup surface side. [Figure 6] FIG. 11 is a cross-sectional view of a pixel included in an image sensor according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] (Embodiment of Imaging Apparatus) 1 is a cross-sectional view showing a schematic configuration of an imaging device 1 using an imaging element 3 according to a first embodiment. The imaging device 1 includes an optical system 2, an imaging element 3, a control unit 4, a lens moving unit 5, and a display unit 6.

[0007] The optical system 2 forms a subject image on the imaging surface (the surface on the optical system 2 side) of the image sensor 3. The optical system 2 is made up of a lens 2a, a focusing lens 2b, and a lens 2c. The focusing lens 2b is a lens for adjusting the focus of the optical system 2. The focusing lens 2b is configured to be movable in the direction of an optical axis O that is parallel to the Z direction in the figure.

[0008] The lens moving unit 5 has an actuator (not shown). The lens moving unit 5 moves the focusing lens 2b in the direction of the optical axis O by using this actuator. The imaging element 3 captures an image of a subject and outputs an image signal. The imaging element 3 has imaging pixels and focus detection pixels (AF pixels). The imaging pixels output a signal (image signal) used for generating an image. The focus detection pixels output a signal (focus detection signal) used for detecting a focus state. The control unit 4 controls each unit such as the imaging element 3, and generates image data by performing image processing or the like on the image signal output by the imaging element 3. The control unit 4 records the image data on a recording medium (not shown) and displays an image based on the image data on the display unit 6. The display unit 6 is a display device having a display member such as a liquid crystal panel.

[0009] Furthermore, the control unit 4 performs focus detection processing required for automatic focus adjustment (AF) of the optical system 2 using a known phase difference detection method. Specifically, the control unit 4 detects the in-focus position of the focusing lens 2b for forming an image by the optical system 2 on the imaging surface of the imaging element 3. The control unit 4 detects the amount of deviation between the current position of the focusing lens 2b and the in-focus position based on a focus detection signal output from a focus detection pixel in the imaging element 3. The control unit 4 moves the focusing lens 2b based on the detected amount of deviation, thereby automatically adjusting the focus.

[0010] (First embodiment of the image sensor) Fig. 2 is a partially enlarged view of the image sensor 3 of the first embodiment as viewed from the imaging surface side, i.e., from the -Z side of Fig. 1. The image sensor 3 has a plurality of pixels PX arranged at a pitch (period) P in the X and Y directions of Fig. 2. Although some pixels PX are omitted in Fig. 2, a large number of pixels PX may be arranged in each of the X and Y directions, for example, 1000 or more pixels PX.

[0011] Each pixel PX is formed with any one of green color filters G0, G1, G2, a blue color filter B, a red color filter R, and a focus detection color filter F. As shown in FIG. 2, the pixels PX are arranged in a so-called Bayer array, for example. Here, the green color filters G0, G1, and G2 are transmissive films that selectively transmit light in the green wavelength range. The spectral transmission characteristics of the green color filters G0, G1, and G2 are basically the same. As described later, it is necessary to distinguish and explain the pixels PX according to the areas of the green color filters G0, G1, and G2, so different symbols are added according to the areas. The green color filters G0, G1, and G2 are also referred to as green color filters G collectively or individually. The area of ​​the color filter is the area in a plane (XY plane) that intersects with the direction in which light enters the imaging element 3 (+Z direction), that is, the area of ​​the part through which the color filter transmits light.

[0012] The blue color filter B is a transmissive film that selectively transmits light in the blue wavelength range, and the red color filter R is a transmissive film that selectively transmits light in the red wavelength range. Selective transmission means that light in that wavelength range is transmitted with a higher transmittance than light in other wavelength ranges. A pixel PX having a green color filter G is an imaging pixel that is relatively sensitive to green light, and is hereinafter also referred to as a G pixel. A pixel PX having a blue color filter B is an imaging pixel that is relatively sensitive to blue light, and is hereinafter also referred to as a B pixel. A pixel PX having a red color filter R is an imaging pixel that is relatively sensitive to red light, and is hereinafter also referred to as an R pixel.

[0013] The focus detection color filters F provided in the focus detection pixels PX4 and PX6 are, for example, transmissive films that selectively transmit light in the green wavelength range, similar to the green color filters G. However, a transmissive film that selectively transmits light in the blue wavelength range in addition to the green wavelength range may be used, or a transmissive film that selectively transmits light in the red wavelength range in addition to the green wavelength range may be used. Alternatively, a transmissive film that selectively transmits light in the blue wavelength range and light in the red wavelength range may be used, or a transmissive film that transmits light in all wavelength ranges may be used.

[0014] Using a transmissive film that selectively transmits light in the green wavelength range as the focus detection color filter F has the advantage of being able to detect the focus state by prioritizing light in the green wavelength range, similar to the visual sensitivity of the human eye. On the other hand, using a transmissive film that transmits light in many wavelength ranges as the focus detection color filter F allows for detection of the focus state using a greater amount of light, i.e., strong in dark places.

[0015] The green color filter G, the blue color filter B, the red color filter R, and the focus detection color filter F are collectively or individually referred to as color filters CF. The shape of the color filter CF in the XY plane is, for example, a square. The green color filter G can also be interpreted as a first transmission film that selectively transmits a first wavelength range, and the focus detection color filter F can also be interpreted as a second transmission film that transmits a second wavelength range.

[0016] Fig. 3 shows a partial cross-sectional view of the imaging element 3. Fig. 3 shows an XZ cross section of the portion enclosed by the dashed line CL shown in Fig. 2 (from pixel PX1 to a part of pixel PX6) as viewed from the +Y direction. As shown in Fig. 3, each pixel PX includes, in order from the bottom in Fig. 3, a photoelectric conversion unit PD, wiring 33, a first planarization layer 34, a color filter CF, a second planarization layer 35, and a microlens 36. The photoelectric conversion unit PD includes a photodiode formed of a semiconductor such as silicon, for example, and converts light incident on the photoelectric conversion unit PD into electric charges. The electric charges converted by the photoelectric conversion unit PD are amplified by a transistor such as an amplifying transistor (not shown), and are read out as an image signal to the control unit 4 shown in Fig. 1 via the wiring 33.

[0017] The first planarization layer 34 and the second planarization layer 35 are provided to reduce unevenness on their surfaces (end faces on the -Z side), and are made of a component transparent to visible light, such as glass or resin. A microlens 36 is provided on the second planarization layer 35 (on the -Z side), and the microlens 36 collects light incident on each pixel PX and transmits it to the photoelectric conversion unit PD. When an image by the optical system 2 is formed near the surface of the microlens 36, the image is captured with the sharpest resolution. However, since the surface of the microlens 36 is uneven and therefore unsuitable as an imaging surface as a reference surface, in this specification, the interface between the second planarization layer 35 and the microlens 36 is described as the imaging surface. However, a surface slightly shifted above or below (in the Z direction) may be considered as the imaging surface.

[0018] The color filter CF of each pixel PX is formed on the upper end surface (-Z side end surface) of the first planarization layer 34 parallel to the imaging surface. A light shielding member 31 is provided between each of the color filters CF. The light shielding member 31 can be formed of a material containing resin or metal. Furthermore, an insulating member 37 is formed between the photoelectric conversion units PD of each pixel PX.

[0019] A shielding portion 32 that blocks approximately the left half (-X side) of the incident surface of the photoelectric conversion unit PD of the focus detection pixel PX4 is provided on the incident surface (the end surface on the -Z side) of the photoelectric conversion unit PD. Although not shown in Fig. 3, a shielding portion 32 that blocks approximately the right half (+X side) of the incident surface of the photoelectric conversion unit PD of the focus detection pixel PX6 is also provided on the incident surface of the photoelectric conversion unit PD of the focus detection pixel PX6. The principles and methods of detecting the focus state by these focus detection pixels PX4 and PX6 are disclosed in Patent Document 1 and are publicly known, and therefore a description thereof will be omitted.

[0020] The position where the shielding portion 32 is provided is not limited to the incident surface of the photoelectric conversion portion PD described above, but may be provided anywhere between the microlens 36 and the incident surface of the photoelectric conversion portion PD. In FIG. 2, for each pixel PX, only the color filter CF, the light blocking member 31, and the shielding portion 32 are shown, and other members such as the microlens 36 and the photoelectric conversion portion PD are not shown.

[0021] Hereinafter, with reference to FIG. 2 and FIG. 3, a problem that occurs when the areas of the green color filters G0, G1, and G2 are equal will be described. As described above, in the image sensor 3 of the first embodiment, the color filters CF of each color are arranged in a so-called Bayer array. Some of the pixels PX (B pixels) in which blue color filters B would normally be arranged in the Bayer array are replaced with focus detection pixels PX4 and PX6, and focus detection color filters F are arranged in place of the blue color filters B.

[0022] In the focus detection pixels PX4 and PX6 that replace the B pixels, the amount of light incident on the photoelectric conversion unit PD and the amount of charge generated in the photoelectric conversion unit PD increase compared to the original B pixels in the Bayer array. A silicon photodiode is more sensitive to light in the green wavelength range than to light in the blue wavelength range, so if the focus detection color filter F has the same spectral transmission characteristics as the green color filter G, light in a wavelength range with higher sensitivity enters the silicon photodiode compared to the original B pixel, and the amount of charge generated in the photoelectric conversion unit PD increases. When the focus detection color filter F transmits light in two or more wavelength ranges of blue, red, and green, the wavelength range of the incident light increases compared to the original B pixel, and the amount of light that reaches the photoelectric conversion unit PD increases, generating more electric charge.

[0023] As a result, the amount of charges e1, e2 generated in the photoelectric conversion unit PD in the focus detection pixel PX4 that leaks to the adjacent imaging pixels PX3, PX5 also increases compared to when the focus detection pixels PX4, PX6 were the original B pixels. As a result, in adjacent imaging pixels PX3, PX5, PX8, PX9, etc., the charge accumulated in each photoelectric conversion unit PD may increase compared to when focus detection pixels PX4 and PX6 are B pixels, which may result in an increase in the output image signal.

[0024] Furthermore, compared to when focus detection pixel PX4 is an original B pixel, the amount of light incident on the photoelectric conversion unit PD of each pixel in the adjacent imaging pixels PX3, PX5, PX8, and PX9 may increase due to stray light entering through focus detection pixel PX4. As shown in Figure 3, light rays L1 and L2 incident on the imaging element 3 at a large angle of incidence enter the microlens 36 and color filter CF of one pixel PX, and then a portion of the light passes through the light-shielding portion 31, passes through the color filter CF of an adjacent pixel PX, and enters the photoelectric conversion unit PD of the adjacent pixel and is photoelectrically converted.

[0025] In the case of light ray L1, after it enters the microlens 36 and green color filter G0 of pixel PX1, which is a G pixel, a portion of the light passes through the light-shielding portion 31, passes through the blue color filter B of pixel PX2, which is an adjacent B pixel, and enters the photoelectric conversion unit PD of pixel PX2 and is photoelectrically converted. In this case, the transmission characteristics of the color filters CF of pixels PX1 and PX2 are different, and the light of the light ray L1 in the blue and red wavelength ranges is attenuated by the green color filter G0, and the light of the green and red wavelength ranges is attenuated by the blue color filter B. Therefore, the light ray L1 is attenuated to some extent in all wavelength ranges, and the charge generated in the photoelectric conversion unit PD of pixel PX2 by the light ray L1 is relatively small.

[0026] On the other hand, after the light ray L2 enters the microlens 36 and the focus detection color filter F of the focus detection pixel PX4, a portion of the light ray L2 passes through the light-shielding portion 31, passes through the green color filter G2 of the adjacent G pixel, pixel PX5, and enters the photoelectric conversion portion PD of pixel PX5 where it is photoelectrically converted. In this case, if the focus detection color filter F transmits light in the green wavelength range, the light in the green wavelength range of the light beam L2 is incident on the photoelectric conversion unit PD of the pixel PX5 without being significantly attenuated. As a result, there is a risk that a relatively large amount of charge due to the light beam L2 will be generated in the photoelectric conversion unit PD of the pixel PX5.

[0027] The light ray L3 is incident on the microlens 36 and the focus detection color filter F of the focus detection pixel PX4, and then incident on the photoelectric conversion unit PD of the pixel PX4, and then passes through the insulating member 37 to be incident on the photoelectric conversion unit PD of the adjacent pixel PX5, where it is photoelectrically converted. The light ray L3 may also increase the image signal output by the pixel PX5, compared to when the focus detection pixel PX4 is an original B pixel.

[0028] As described above, the leakage of charges from the focus detection pixels PX4 and PX6 and the intrusion of stray light both increase the image signal of the pixel PX adjacent to the focus detection pixels PX4 and PX6, that is, act as a noise component. In particular, pixel PX5 is adjacent to focus detection pixels PX4 and PX6 on both sides in the X direction, and is therefore likely to be affected by noise components from both focus detection pixels PX4 and PX6. Although the amount of these noise components is very small, they will significantly degrade the quality of the captured image because the human eye is extremely sensitive to local changes in brightness or hue within an image of uniform brightness and color.

[0029] In the image sensor 3 of the first embodiment, the area of ​​the green color filters G0, G1, G2 of each G pixel is made different depending on the number of focus detection pixels PX4, PX6 adjacent to that G pixel. This makes it possible to make the magnitude of the image signal output by each G pixel roughly equal, regardless of whether or not the G pixel is adjacent to the focus detection pixels PX4, PX6.

[0030] The areas of the green color filters G0, G1, and G2 of each G pixel will be described with reference to FIG. 2, the green color filter G0 is disposed in a pixel PX that is a G pixel and adjacent to which the focus detection pixels PX4, PX6 are not disposed. Adjacent here means that one of the sides that are the boundaries of the green color filter G faces one of the sides that are the boundaries of the focus detection color filters F of the focus detection pixels PX4, PX6.

[0031] As shown in FIG. 2, the width of the light blocking member 31 around the green color filter G0 is γ, so the length of one side of the green color filter G0 is (P-γ). The area S0 is the square of the length of one side, so S0 = (P-γ) 2 ··· Equation (1) It is. The area S0 is S0 = (P + γ - 2γ) 2 ··· Equation (2) Using equation (2) makes it easier to compare the size relationship between area S1 and area S2, which will be described later.

[0032] 2, the green color filter G1 is a G pixel, and is disposed at pixels PX3, PX8, and PX9, adjacent to which focus detection pixels PX4 and PX6 are disposed. The width of the light blocking member 31 surrounding the green color filter G1 is β, which is greater than the above-mentioned γ. The length of one side of the green color filter G1 is (P+γ-2β), and the area S1 is the square of the length of one side, so S1 = (P + γ - 2β) 2 ··· Equation (3) It is. As described above, since β>γ, when formula (2) and formula (3) are compared, the area S1 of the green color filter G1 is smaller than the area S0 of the green color filter G0.

[0033] The green color filter G2 in Fig. 2 is a G pixel, and is disposed in pixels PX5 and PX7 adjacent to which two focus detection pixels PX4 and PX6 are disposed. Although not shown in Fig. 2, a focus detection pixel similar to focus detection pixel PX4 is disposed adjacent to pixel PX7 on the +X side. The width of the light blocking member 31 around the green color filter G2 is α, which is greater than the above-mentioned γ and β. The length of one side of the green color filter G2 is (P+γ-2α), and the area S2 is the square of the length of one side, so S2 = (P + γ-2α) 2 ··· Equation (4) It is. As described above, since α>β>γ, when comparing formulas (2), (3), and (4), the area S2 of the green color filter G2 is smaller than the area S1 of the green color filter G1. S0 > S1 > S2 ··· Equation (5) It is.

[0034] As described above, by reducing the area of ​​the green color filters G1, G2, the amount of light passing through the green color filters G1, G2 can be reduced, and the sensitivity of the G pixels having the green color filters G1, G2 can be reduced. Therefore, by changing the area S0, S1, S2 of the green color filters G according to the number of adjacent focus detection pixels PX4, PX6, the increase in noise from the focus detection pixels PX4, PX6 can be offset by the decrease in sensitivity due to the reduction in area. This makes it possible to make the magnitude of the image signal output by each G pixel approximately equal, regardless of whether or not each G pixel is adjacent to the focus detection pixels PX4, PX6.

[0035] Furthermore, by changing the area of ​​the green color filter G by changing the widths α, β, and γ of the light-shielding members 31 provided between the green color filters G, the stray light itself received by the G pixels from the focus detection pixels PX4 and PX6 can be reduced. 3 is stray light that is incident on the microlens 36 of the focus detection pixel PX4 and then on the photoelectric conversion unit PD of pixel PX5. Since pixel PX5 is adjacent to focus detection pixel PX4, in the image sensor 3 of the first embodiment, the width of the light blocking member 31 around the green color filter G2 of pixel PX5 is set to α.

[0036] On the other hand, the width of the light shielding member 31 between the pixels PX1 and PX2 through which the above-mentioned light ray L1 passes is γ which is smaller than α. Therefore, the light ray L2 is absorbed by the shielding member 31 more strongly than the light ray L1. Therefore, in this example, the problem that the charge caused by the light ray L2 in the photoelectric conversion unit PD of the above-mentioned pixel PX5 is generated relatively more than the charge caused by the light ray L1 in the photoelectric conversion unit PD of the pixel PX2 is solved or alleviated.

[0037] 2, the light shielding members 31 provided between the green color filter G and the focus detection color filter F can also be interpreted as a first light shielding portion. Also, the light shielding members 31 provided between the green color filter G and the blue color filter B or between the green color filter G and the red color filter R can also be interpreted as a second light shielding portion. By setting the widths α and β of the first light shielding portions to be wider than the width γ of the second light shielding portion, it can also be interpreted that the amount of light incident on the photoelectric conversion units PD of the G pixels adjacent to the focus detection pixels PX4 and PX6 is reduced below the amount of light incident on the photoelectric conversion units PD of the G pixels not adjacent to the focus detection pixels PX4 and PX6.

[0038] Furthermore, by changing the area of ​​the green color filter G, the amount of light passing through the green color filter G and entering the photoelectric conversion unit PD can be changed by an amount more than proportional to the change in the area of ​​the green color filter G. This phenomenon will be explained with reference to FIG.

[0039] Fig. 4 is an enlarged view of the microlens 36, color filters CF (G0, G2), and light-shielding portion 31 of one pixel PX from the cross-sectional view of the image sensor 3 shown in Fig. 3. Fig. 4(a) is an enlarged view of pixel PX1, and Fig. 4(b) is an enlarged view of pixel PX5. In the process of forming the color filter CF and the light shielding member 31, first, the light shielding member 31 is formed on the first planarization layer 34 by lithography or the like, and then the color filter CF is formed by lithography or the like. Since the color filter CF is formed by coating or other means on the step caused by the light shielding member 31, the thickness Tl, Tr of the peripheral portion of the color filter CF is thicker than the thickness Tc of the center portion due to the influence of the light shielding member 31.

[0040] In the case of pixel PX1 shown in FIG. 4(a), the width of light-shielding portion 31 is relatively small, γ, so the width (one side) W10 (=P-γ) of green color filter G0 is relatively large. Therefore, the distance between peripheral portions 380L and 380R where the thickness of green color filter G0 is thick is also relatively wide. As a result, most of light rays L11-L12 from microlens 36 pass through the thin central portion (region A0 whose thickness is approximately Tc) without passing through peripheral portions 380L and 380R of green color filter G0.

[0041] On the other hand, in the case of the pixel PX5 shown in FIG. 4(b), the width of the light shielding portion 31 is relatively large as α, so the width (one side) W11 (=P+γ-2α) of the green color filter G2 is relatively small. Therefore, the distance between the peripheral portion 382L and the peripheral portion 382R where the thickness of the green color filter G2 becomes thick is also relatively narrow, and as a result, the area A2 where the thickness is approximately Tc is also narrower than the above-mentioned area A0. As a result, the peripheral portion of the light beams L11-L1 from the microlens 36 passes through the peripheral portions 380L and 380R of the green color filter G2, and more light is absorbed by the green color filter G2, and the amount of light decreases. Therefore, the amount of light can be reduced by more than the amount proportional to the reduction in the area of ​​the green color filter G.

[0042] Both the reduction in stray light and the reduction in the amount of light due to the substantial increase in the thickness of the green color filter G offset the increase in noise from the focus detection pixels PX4, PX6. Therefore, the magnitude of the image signal output by each G pixel can be made roughly equal, regardless of whether or not the G pixel is adjacent to the focus detection pixels PX4, PX6.

[0043] 2, the areas of the blue color filter B and the red color filter R are the same as the area S0 of the green color filter G0 that is not adjacent to the focus detection pixels PX4 and PX6. However, the areas of the blue color filter B and the red color filter R are not limited to the area S0, and may be greater than or less than the area S0. In order to suppress the adverse effects of stray light between pixels and realize a highly sensitive image sensor 3, it is desirable that the areas of the blue color filter B and the red color filter R are the same as the above-mentioned area S0.

[0044] (Second embodiment of the image sensor) Fig. 5 is a partial enlarged view of the imaging element 3a of the second embodiment as viewed from the imaging surface side, i.e., from the -Z side of Fig. 1. The imaging element 3a of the second embodiment differs from the imaging element 3 of the first embodiment in that it does not have a light blocking member 31, and is otherwise similar to the imaging element 3 of the first embodiment. Therefore, the same reference numerals are used to designate common members, and descriptions thereof will be omitted as appropriate.

[0045] Since the image sensor 3a does not have a light shielding member 31, the color filter CF of one pixel PX is in direct contact with the color filter CF of an adjacent pixel, as shown in Fig. 5. In the image sensor 3a, the focus detection pixels PX14 and PX16 also have focus detection color filters F, and there is a risk that noise will be caused to adjacent pixels due to stray light, charge leakage, and the like.

[0046] In the image sensor 3a as well, the area of ​​the green color filter G of the G pixel adjacent to the focus detection pixels PX14, PX16 can be made smaller than the area of ​​the green color filter G of the G pixel not adjacent to these pixels, thereby offsetting the noise caused by the above-mentioned stray light, charge leakage, etc. Of the G pixels, pixels PX12, PX13, PX14, PX18, and PX19 are adjacent to one focus detection pixel, PX14, PX16, and pixels PX15 and PX17 are adjacent to two focus detection pixels, PX14 and PX16. Although not shown, it is assumed that a focus detection pixel similar to focus detection pixel PX14 is disposed adjacent to the +X side of PX17.

[0047] 5, the focus detection color filters F of the focus detection pixels PX14 and PX16 can be expanded toward the adjacent G pixels to make the areas of the green color filters G0, G1, and G2 different from each other. The lengths of the expanded focus detection color filters F in the X and Y directions are δ (δ>P).

[0048] The green color filter G0 that is not adjacent to the focus detection pixels PX14 and PX16 is not affected by the expansion of the focus detection color filter F, and therefore its area S10 is the square of the pitch P (P 2 ) The green color filter G1 adjacent to one of the focus detection pixels PX14, PX16 has its area along one side reduced by the expansion of the focus detection color filter F, so its area S11 is smaller than the above-mentioned S10. The green color filter G2 adjacent to the two focus detection pixels PX14, PX16 has its areas along both sides reduced by the expansion of the focus detection color filter F, so its area S12 is smaller than the above-mentioned S11. This makes it possible to reduce the sensitivity of the G pixels having the green color filters G1, G2.

[0049] Therefore, by changing the areas S10, S11, S12 of the green color filters G in accordance with the number of adjacent focus detection pixels PX14, PX16, the increase in noise from the focus detection pixels PX14, PX16 can be offset by the decrease in sensitivity due to the reduction in area. This makes it possible to make the magnitude of the image signal output by each G pixel roughly equal, regardless of whether or not the G pixel is adjacent to the focus detection pixels PX14, PX116.

[0050] Moreover, the reduction in the amount of light due to the substantial increase in the thickness of the green color filter G described in the above-mentioned first embodiment can also be achieved in the second embodiment. This phenomenon will be explained with reference to FIG.

[0051] 6(a) is an enlarged cross-sectional view of pixel PX11 in FIG. 5, and FIG. 6(b) is an enlarged cross-sectional view of pixel PX15 in FIG. 6(a) and 6(b), similarly to FIGS. 4(a) and 4(b), only the microlens 36 and the color filter CF are shown in an enlarged scale. In addition, in FIG. 6, in the process of forming the color filter CF, the focus detection color filter F, the blue color filter B, and the red color filter R are formed before the green color filter G is formed on the first planarization layer 34.

[0052] The green color filter G is formed after the steps created by the focus detection color filter F and the blue color filter B are formed. Due to the influence of these steps, the thicknesses Tl and Tr of the peripheral portions are thicker than the thickness Tc of the center portion. In the case of pixel PX11 shown in FIG. 6(a), the width W20 (=P) of the green color filter is relatively large. Therefore, the distance between the peripheral portions 390L and 390R where the thickness of the green color filter G0 is thick is also relatively wide. As a result, most of the light beams L11-L12 from the microlens 36 pass through the thin central portion (region A10 having a thickness of approximately Tc) without passing through the peripheral portions 390L and 390R of the green color filter G0.

[0053] On the other hand, in the case of the pixel PX15 shown in FIG. 6(b), the width W21 (=2P-δ) of the green color filter G2 is relatively small. Therefore, the interval between the peripheral portion 392L and the peripheral portion 392R where the thickness of the green color filter G2 is thick is also relatively narrow, and as a result, the area A12 where the thickness is approximately Tc is also narrower than the above-mentioned area A10. As a result, the peripheral portion of the light beam L11-L1 from the microlens 36 passes through the thick peripheral portions 392L, 392R of the green color filter G2, and more light is absorbed by the green color filter G2, and the amount of light is reduced. Therefore, even in the image sensor 3a of the second embodiment, the amount of light can be reduced more than proportional to the reduction in the area of ​​the green color filter G.

[0054] In the second embodiment, when the focus detection color filter F and the green color filter G have the same spectral transmission characteristics, it is not possible to expect an increase or decrease in the sensitivity of the pixel by simply increasing or decreasing the area of ​​the green color filter G and the area of ​​the focus detection color filter F. However, due to the substantial increase or decrease in the thickness of the green color filter G that occurs additionally by increasing or decreasing the area of ​​the green color filter G, the sensitivity of the G pixel can be increased or decreased even when the focus detection color filter F and the green color filter G have the same spectral transmission characteristics.

[0055] Even in the second embodiment, when the spectral transmittance characteristics of the focus detection color filter F and the green color filter G are different, the sensitivity of the G pixel arranged adjacent to the focus detection pixels PX14, PX16 can be changed simply by increasing or decreasing the area of ​​the green color filter G and the area of ​​the focus detection color filter F.

[0056] In the first and second embodiments described above, the arrangement of the pixels PX is not necessarily limited to the Bayer arrangement. The pitch of the pixels PX may be different in the X direction and the Y direction, and the length of one side of the pixels PX and the color filters CF may also be different in the X direction and the Y direction. Furthermore, the pixels PX disposed adjacent to the focus detection pixels PX14, PX16 are not necessarily limited to the above-mentioned G pixels, and may be pixels that are relatively sensitive to light other than green. Further, the photoelectric conversion unit PD is not limited to a photodiode made of silicon, but may be a photodiode or a photoresistor made of an organic film. Moreover, the imaging device of the above-described embodiment may include the imaging element 3a of the second embodiment instead of the imaging element 3 of the first embodiment.

[0057] According to the above-described first and second embodiments, the following advantageous effects can be obtained. (1) From a first viewpoint, the image sensor 3, 3a of the first or second embodiment includes a first pixel (G pixel) having a first transmissive film G that transmits light in a first wavelength range, and a second pixel (focus detection pixel) having a second transmissive film F that transmits light in a second wavelength range, and is configured such that the area of ​​the first transmissive film G of the first pixel (G pixel) to which the second pixel (focus detection pixel) is adjacent is smaller than the area of ​​the first transmissive film G of the first pixel (G pixel) to which the second pixel (focus detection pixel) is not adjacent. This configuration makes it possible to make the magnitude of the image signal output from each first pixel (G pixel) roughly equal, regardless of whether the first pixel (G pixel) is adjacent to a second pixel (focus detection pixel). In other words, it is possible to reduce the change in the magnitude of the image signal that conventionally occurs in pixels near the focus detection pixel, and to output a more uniform, high-quality image signal.

[0058] (2) The area of ​​the first transmissive film G of a first pixel (G pixel) adjacent to two second pixels (focus detection pixels) is smaller than the area of ​​the first transmissive film G of a first pixel (G pixel) adjacent to one second pixel (focus detection pixel). This makes it possible to make the magnitude of the image signal output by each first pixel (G pixel) roughly equal when the first pixel (G pixel) is adjacent to one or two second pixels (focus detection pixels) and when the first pixel (G pixel) is not adjacent to a second pixel (focus detection pixel). (3) The third pixel (B pixel, R pixel) has a third transparent film B, R that transmits light in a third wavelength range different from the first wavelength range, and the area of ​​the first transparent film G of the first pixel (G pixel) adjacent to the second pixel (focus detection pixel) is smaller than the area of ​​the third transparent films B, R. This makes it possible to reduce variation in the magnitude of the image signals output by the first pixel (G pixel) and the third pixel (B pixel, R pixel) adjacent to the second pixel (focus detection pixel). (4) By configuring the area of ​​the first transparent film G of the first pixel (G pixel) that is not adjacent to the second pixel (focus detection pixel) to be approximately equal to the area of ​​the third transparent films B, R, it is possible to reduce variation in the magnitude of the image signals output by the first pixel (G pixel) and the third pixel (B pixel, R pixel).

[0059] (5) From the second viewpoint, the image sensor 3, 3a of the first or second embodiment comprises a first pixel (G pixel) having a first transmissive film G having an area (A0, A2, A10, A12) that transmits light in a first wavelength range and has a predetermined thickness Tc, and a second pixel (focus detection pixel) having a second transmissive film F that transmits light in a second wavelength range, and the area (A2, A12) of the first pixel (G pixel) to which the second pixel (focus detection pixel) is adjacent is narrower than the area (A0, A10) of the first pixel (G pixel) to which the second pixel (focus detection pixel) is not adjacent. With this configuration, in the first pixel (G pixel) adjacent to the second pixel (focus detection pixel), the peripheral portions of the light rays L11-L1 from the microlens 36 pass through peripheral portions 380L, 380R, 382L, and 382R of the first transparent film G, which have different thicknesses, and since the amount of light absorption by the first transparent film G differs, the amount of image signal output can be increased or decreased.

[0060] (6) By configuring the area of ​​a first pixel (G pixel) that is adjacent to two second pixels (focus detection pixels) to be narrower than the area of ​​a first pixel (G pixel) that is adjacent to one second pixel (focus detection pixel), the size of the image signal output by each first pixel (G pixel) can be made roughly equal when the first pixel (G pixel) is adjacent to one or two second pixels (focus detection pixels) and when it is not adjacent to a second pixel (focus detection pixel). (7) By configuring the thickness of the peripheral portion of the first transparent film G to be thicker than a predetermined thickness Tc, the amount of image signal output by a first pixel (G pixel) that is adjacent to a second pixel (focus detection pixel) can be reduced compared to the amount of image signal output by a first pixel (G pixel) that is not adjacent to a second pixel (focus detection pixel).

[0061] (8) From the third viewpoint, the image sensor 3 of the first embodiment includes a first pixel (G pixel) having a first transmissive film G that transmits light in a first wavelength range, a second pixel (focus detection pixel) having a second transmissive film F that transmits light in a second wavelength range, a third pixel having third transmissive films B, R that transmit light in a third wavelength range different from the first wavelength range, a first light-shielding portion 31 between the first transmissive film G and the second transmissive film F, and a second light-shielding portion 31 between the first transmissive film G and the third transmissive films B, R, and the widths α, β of the first light-shielding portion 31 are wider than the width γ of the second light-shielding portion 31. This configuration makes it possible to make the magnitude of the image signal output from each first pixel (G pixel) roughly equal, regardless of whether the first pixel (G pixel) is adjacent to a second pixel (focus detection pixel). In other words, it is possible to reduce the change in the magnitude of the image signal that conventionally occurs in pixels near the focus detection pixel, and to output a more uniform, high-quality image signal. (9) The first pixel (G pixel) receives light in a first wavelength range among the light transmitted through the optical system and outputs a signal used for image generation, and the second pixel (focus detection pixel) receives light in a second wavelength range among the light transmitted through the optical system and outputs a signal used for focus detection of the optical system, so that an output signal that is not affected by noise caused by the second pixel (focus detection pixel) (noise is cancelled) can be obtained from the first pixel (G pixel) adjacent to the second pixel (focus detection pixel). This also has the effect of increasing the degree of freedom in the arrangement of the second pixel (focus detection pixel).

[0062] (10) The second transmissive film F is configured to transmit light in a wavelength range that includes at least the first wavelength range, thereby making it possible to perform focus detection that is tailored to the visual sensitivity of the human eye, or that uses a large amount of light from many wavelength ranges, i.e., focus detection that is strong in dark places.

[0063] An imaging device according to an 11th embodiment includes the imaging element 3, 3a according to the first or second embodiment described above, and a generating unit that generates image data based on a signal from the imaging element 3, 3a. This configuration makes it possible to reduce the variation in image signal magnitude that conventionally occurs in pixels near focus detection pixels, and to generate more uniform, high-quality image data.

[0064] Although various embodiments and modifications have been described above, the present invention is not limited to these. Each embodiment and modification may be applied alone or in combination. Other aspects that are conceivable within the scope of the technical concept of the present invention are also included in the scope of the present invention. [Explanation of symbols]

[0065] 1: imaging device, 2: imaging lens, 3: imaging element, 4: control unit, 5: lens movement unit, PX: pixel 30, G0, G1, G2: green color filters, B: blue color filter, R: red color filter, F: focus detection color filter, 31: light shielding member, 32: shielding portion, 33: wiring, 34: first planarization layer, 35: second planarization layer, 35: microlens, PD: photoelectric conversion unit, 37: insulating member

Claims

1. A first permeable film having a first surface having a first region into which light is incident and a second region into which light is incident and disposed around the first region, and a second surface opposite the first surface having a third region facing the first region and a fourth region facing the second region; a first photoelectric conversion unit that converts light transmitted from the first region through the second surface and light transmitted from the second region through the second surface into electric charges; Equipped with The first permeable film has a thickness from the second region to the fourth region that is thicker than a thickness from the first region to the third region in a direction from the second surface to the first surface. Image sensor.

2. The imaging element according to claim 1, The first transparent film is formed such that the second region rises higher than the first region in a direction from the second surface to the first surface.

3. An imaging element according to claim 1 or claim 2, The first transparent film is formed such that the second region protrudes further than the first region in a direction from the second surface toward the first surface.

4. An imaging element according to any one of claims 1 to 3, An imaging element in which the distance from the first region to the second region in a direction from the second surface toward the first surface is longer than the distance from the third region to the fourth region.

5. An imaging element according to any one of claims 1 to 4, The second surface of the imaging element is flat.

6. An imaging element according to any one of claims 1 to 5, A microlens that transmits light is provided. An imaging element in which light transmitted through the microlens is incident on the first region and the second region.

7. The imaging element according to claim 6, The second region is formed so as to protrude toward the microlens.

8. An imaging element according to claim 6 or claim 7, The second region is an imaging element formed so as to protrude toward the microlens.

9. An imaging element according to any one of claims 6 to 8, An imaging element in which the distance between the second region and the microlens is shorter than the distance between the first region and the microlens.

10. An imaging element according to any one of claims 1 to 9, a second transmitting film having a third surface having a fifth region into which light is incident and a sixth region into which light is incident and disposed around the fifth region; and a fourth surface having a seventh region opposite to the third surface and facing the fifth region and an eighth region facing the sixth region; a second photoelectric conversion unit that converts light transmitted from the fifth region through the fourth surface and light transmitted from the sixth region through the fourth surface into electric charges; Equipped with the second photoelectric conversion unit is disposed adjacent to the first photoelectric conversion unit, An imaging element in which the area of ​​the first region is smaller than the area of ​​the fifth region.

11. The imaging element according to claim 10, The second photoelectric conversion unit is an image sensor arranged adjacent to the first photoelectric conversion unit in the row direction.

12. An imaging element according to claim 10 or claim 11, An imaging element in which, in a direction from the second surface to the first surface, the distance from the first region to the second region is longer than the distance from the third region to the fourth region, and the distance from the fifth region to the sixth region is longer than the distance from the seventh region to the eighth region.

13. An imaging element according to any one of claims 10 to 12, The imaging element, wherein the second surface and the fourth surface are flat.

14. An imaging element according to any one of claims 10 to 13, An imaging element including a shielding portion that blocks a portion of light incident on the second photoelectric conversion portion.

15. The imaging device according to claim 14, the second photoelectric conversion unit having the second transmission film and the shielding unit; An imaging element in which the area of ​​the first region becomes smaller as the number of the second regions arranged adjacent to the first region increases.

16. An imaging element according to claim 14 or claim 15, the second photoelectric conversion unit having the second transmission film and the shielding unit; An imaging element, wherein an area of ​​the first region in which two of the second transparent films are arranged adjacent to each other is smaller than an area of ​​the first region in which one of the second transparent films is arranged adjacent to each other.

17. An imaging element according to any one of claims 10 to 16, an imaging element having a light blocking portion between the first transparent film and the second transparent film; 18. The imaging element according to claim 17, The first transmission film and the first photoelectric conversion unit are each provided in a plurality of parts, an imaging element, wherein a width of the light-shielding portion between the second transparent film and the first transparent film adjacent to which the second transparent film is arranged is wider than a width of the light-shielding portion between the first transparent film and the first transparent film not adjacent to which the second transparent film is arranged.

19. The imaging device according to claim 17 or 18, an imaging element in which a width of the light-shielding portion between the second transparent film and the first transparent film arranged adjacent to the second transparent film becomes wider as the number of the second transparent films arranged adjacent to each other increases.

20. An imaging element according to any one of claims 17 to 19, An imaging element, wherein a width of the light-shielding portion between the first transparent film and the second transparent film, where two of the second transparent films are arranged adjacent to each other, is wider than a width of the light-shielding portion between the first transparent film and the second transparent film, where one of the second transparent films is arranged adjacent to each other.

21. An imaging element according to any one of claims 10 to 20, a pixel having the second transmission film and the second photoelectric conversion unit is a focus detection pixel, an imaging element, wherein a pixel having the first transmissive film and the first photoelectric conversion portion is an imaging pixel;

22. An imaging element according to any one of claims 1 to 21; a generation unit that generates image data based on a signal from the imaging element.

Images