Image pickup element and image pickup device

Abstract

Getting the right exposure for each area of ​​the image. [Solution] The image sensor comprises a plurality of first pixels for imaging having a first transparent film that transmits light in a first wavelength range; second pixels for focus detection having a second transparent film that transmits light in a second wavelength range; a first light-shielding portion provided around one of the first pixels that is adjacent to a second pixel; and a second light-shielding portion provided around one of the first pixels that is not adjacent to a second pixel, wherein the area of ​​the first transparent film of the first pixel adjacent to the second pixel is determined by the 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 the area of ​​the first transparent film of the first pixel adjacent to the second pixel is smaller than the area of ​​the first transparent film of the first pixel that is not adjacent to the second pixel.

Description

[Technical Field]

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

[0002] An image plane phase difference detection type image sensor is known 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 (see, 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] Japanese Patent Application Publication No. 2016-29674 Summary of the Invention

[0004] According to a first aspect of the present invention, an imaging element includes a first transmission 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 on the opposite side to the first surface having a third region facing the first region and a fourth region facing the second region; a second transmission film having a third surface having a fifth region where light is incident and a sixth region where light is incident and disposed around the fifth region; and a fourth surface on the opposite side to the third surface having a seventh region facing the fifth region and an eighth region facing the sixth region; a first photoelectric conversion unit that converts light that has passed from the first region through the second surface and light that has passed from the second region through the second surface into electric charges; a second photoelectric conversion unit that converts light that has passed through the fourth surface from the fifth region and light that has passed through the fourth surface from the sixth region into electric charges; and a shielding unit that shields a portion of the light that is incident on the second photoelectric conversion unit. Equipped with the first transmission film and the first photoelectric conversion unit are each provided in a plurality, and an area of ​​the first region of the first transmission film adjacent to at least one of the second transmission films is smaller than an area of ​​the first region of the first transmission film not adjacent to the second transmission film; The first permeable membrane has a thickness from the second region to the fourth region that is thicker in a direction from the second surface to the first surface than a thickness from the first region to the third region. Ku , The first permeable membrane is formed such that the second region rises higher than the first region in a direction from the second surface toward the first surface. . According to a second aspect of the present invention, an imaging device includes the imaging element described above, and a generating section that generates image data based on a signal from the imaging element. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 is a cross-sectional view schematically showing the configuration of an imaging device. [Figure 2] FIG. 2 is a partially enlarged plan view of the imaging element of the first embodiment, viewed from the imaging surface side. [Figure 3] FIG. 2 is a cross-sectional view of the imaging element according to the first embodiment. [Figure 4] FIG. 2 is a cross-sectional view of a pixel included in the image sensor according to the first embodiment. [Figure 5] FIG. 10 is a partially enlarged plan view of the imaging element of the second embodiment, viewed from the imaging surface side. [Figure 6] FIG. 10 is a cross-sectional view of a pixel included in an image sensor according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0006] (Embodiment of Imaging Device) 1 is a cross-sectional view schematically showing the 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 using this actuator. The image sensor 3 captures an image of a subject and outputs an image signal. The image sensor 3 has imaging pixels and focus detection pixels (AF pixels). The imaging pixels output signals (image signals) used to generate an image. The focus detection pixels output signals (focus detection signals) used to detect the focus state. The control unit 4 controls each unit such as the image sensor 3, and generates image data by performing image processing etc. on the image signals output by the image sensor 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] The control unit 4 also performs focus detection processing required for automatic focusing (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 at which an image formed by the optical system 2 is focused 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 focus detection signals output from focus detection pixels in the imaging element 3. The control unit 4 moves the focusing lens 2b based on the detected amount of deviation, thereby automatically performing focus adjustment.

[0010] (First embodiment of the imaging element) 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 in Fig. 1. The image sensor 3 has a plurality of pixels PX arranged at a pitch (period) P in the X and Y directions in Fig. 2. Although some of the 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.

[0011] Each pixel PX is formed with one of green color filters G0, G1, G2, blue color filter B, red color filter R, and 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 transmittance characteristics of the green color filters G0, G1, and G2 are essentially the same. As will be described later, the pixels PX must be distinguished according to the area of ​​the green color filters G0, G1, and G2, and therefore different reference numerals are assigned to the green color filters G according to their areas. The green color filters G0, G1, and G2 are also referred to collectively or individually as green color filters G. The area of ​​a color filter is the area in a plane (XY plane) that intersects with the direction in which light enters the image sensor 3 (the +Z direction), i.e., the area of ​​the portion 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. Note that "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 therefore is also referred to as a G pixel hereinafter. A pixel PX having a blue color filter B is an imaging pixel that is relatively sensitive to blue light, and therefore is also referred to as a B pixel hereinafter. A pixel PX having a red color filter R is an imaging pixel that is relatively sensitive to red light, and therefore is also referred to as an R pixel hereinafter.

[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 also be used, or a transmissive film that selectively transmits light in the red wavelength range in addition to the green wavelength range may also be used. Alternatively, a transmissive film that selectively transmits light in the blue wavelength range and light in the red wavelength range may also be used, or a transmissive film that transmits light in all wavelength ranges may also 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., effective 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 also 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 light in a first wavelength range, and the focus detection color filter F can also be interpreted as a second transmission film that transmits light in 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 part of pixel PX6) as viewed from the +Y direction. 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, for example, a photodiode formed of a semiconductor such as silicon, 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 amplifier transistor (not shown), and are read out as an image signal via wiring 33 to the control unit 4 shown in FIG. 1.

[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. The image formed by the optical system 2 is sharpest when it is formed near the surface of the microlens 36. However, since the surface of the microlens 36 is uneven and therefore unsuitable as an imaging surface as a reference surface, the interface between the second planarization layer 35 and the microlens 36 will be described as the imaging surface in this specification. However, a surface slightly shifted above or below (in the Z direction) may also 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 color filter CF. The light-shielding member 31 can be made of a material containing resin or metal. Furthermore, an insulating member 37 is formed between the photoelectric conversion units PD of the pixels PX.

[0019] The incident surface (the end surface on the -Z side) of the photoelectric conversion unit PD of the focus detection pixel PX4 is provided with a shielding portion 32 that shields approximately the left half (-X side) of the incident surface of the photoelectric conversion unit PD from light. Although not shown in FIG. 3, the incident surface of the photoelectric conversion unit PD of the focus detection pixel PX6 is also provided with a shielding portion 32 that shields approximately the right half (+X side) of the incident surface from light. The principles and methods of detecting the focus state by these focus detection pixels PX4 and PX6 are disclosed in Patent Document 1 and other documents and are publicly known, so 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 FIGS. 2 and 3, a problem that occurs when the green color filters G0, G1, and G2 have the same area 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) where blue color filters B would normally be arranged in a 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. Silicon photodiodes are more sensitive to light in the green wavelength range than to light in the blue wavelength range, so if the spectral transmittance characteristics of the focus detection color filter F are the same as those of the green color filter G, light in a wavelength range with higher sensitivity will be incident compared to the original B pixel, and the amount of charge generated in the photoelectric conversion unit PD will increase. 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 case of 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 and e2 generated in the photoelectric conversion unit PD within the focus detection pixel PX4 that leaks to the adjacent imaging pixels PX3 and PX5 also increases compared to when the focus detection pixels PX4 and 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, and the output image signal may increase.

[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 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 portion PD of pixel PX2, where it is photoelectrically converted. In this case, the transmission characteristics of the color filters CF of pixel PX1 and pixel PX2 are different, and light in the blue and red wavelength ranges of light ray L1 is attenuated by the green color filter G0, and light in the green and red wavelength ranges is attenuated by the blue color filter B. Therefore, light ray L1 is attenuated to some extent across all wavelength ranges, and the amount of charge generated in the photoelectric conversion unit PD of pixel PX2 by light ray L1 is relatively small.

[0026] On the other hand, after light ray L2 enters the microlens 36 and focus detection color filter F of 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 pixel PX5, which is an adjacent G pixel, 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 ray L2 is incident on the photoelectric conversion unit PD of the pixel PX5 without being significantly attenuated, which may result in a relatively large amount of charge being generated in the photoelectric conversion unit PD of the pixel PX5 by the light ray L2.

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

[0028] The leakage of electric charges from the focus detection pixels PX4 and PX6 and the intrusion of stray light described above both increase the image signals of the pixels PX adjacent to the focus detection pixels PX4 and PX6, that is, act as noise components. 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, the human eye is extremely sensitive to local changes in brightness or hue within an image of uniform brightness and color, and so they significantly degrade the quality of the captured image.

[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 varied depending on the number of focus detection pixels PX4, PX6 adjacent to that G pixel, thereby making it possible to make the magnitude of the image signal output by each G pixel roughly equal, regardless of whether 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 at a G pixel PX adjacent to which the focus detection pixels PX4 and PX6 are not disposed. Here, "adjacent" means that one of the sides of the boundary of the green color filter G faces one of the sides of the boundary of the focus detection color filters F of the focus detection pixels PX4 and 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), and the area S0 is the square of the length of one side, so S0=(P-γ) 2 ··· Equation (1) is. The area S0 is S0 = (P + γ - 2γ) 2 ··· Equation (2) Using equation (2) makes it easy to compare the size relationship between area S1 and area S2, which will be described later.

[0032] 2 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-shielding member 31 around the green color filter G1 is β, which is larger 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) is. As described above, β>γ, and therefore, when comparing equations (2) and (3), 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 arranged at pixels PX5 and PX7, adjacent to which two focus detection pixels PX4 and PX6 are arranged. Although not shown in Fig. 2, a focus detection pixel similar to focus detection pixel PX4 is arranged adjacent to pixel PX7 on the +X side. The width of the light-shielding 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) 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) is.

[0034] As described above, by reducing the area of ​​the green color filters G1 and G2, the amount of light passing through the green color filters G1 and G2 can be reduced, thereby lowering the sensitivity of the G pixels that include those green color filters G1 and G2. Therefore, by changing the areas S0, S1, and S2 of the green color filters G in accordance with the number of adjacent focus detection pixels PX4 and PX6, the increase in noise from the focus detection pixels PX4 and PX6 can be offset by the reduced sensitivity due to the reduced area. This makes it possible to roughly equalize the magnitude of the image signal output by each G pixel, regardless of whether the G pixel is adjacent to the focus detection pixel PX4 or PX6.

[0035] Furthermore, by changing the area of ​​the green color filters 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 received by the G pixels from the focus detection pixels PX4 and PX6 can be reduced. 3 is stray light that enters the microlens 36 of the focus detection pixel PX4 and then enters the photoelectric conversion unit PD of pixel PX5. Because pixel PX5 is adjacent to focus detection pixel PX4, in the image sensor 3 of the first embodiment, the width of the light-shielding 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 pixel PX1 and pixel PX2, through which the above-mentioned light ray L1 passes, is γ, which is smaller than α. Therefore, the light ray L2 is absorbed more strongly by the light-shielding member 31 than the light ray L1. Therefore, in this example, the problem that the charge generated by the light ray L2 in the photoelectric conversion unit PD of pixel PX5 is relatively larger than the charge generated by the light ray L1 in the photoelectric conversion unit PD of pixel PX2 is resolved 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 first light-shielding portions. 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 second light-shielding portions. By setting the widths α and β of the first light-shielding portions 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] In addition, by changing the area of ​​the green color filter G, the amount of light that passes through the green color filter G and enters the photoelectric conversion unit PD can be changed by an amount greater than or equal 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 the like on the step caused by the light-shielding member 31, the thicknesses Tl and Tr of the peripheral portions of the color filter CF are thicker than the thickness Tc of the center portion due to the influence of the light-shielding member 31.

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

[0041] On the other hand, in the case of the pixel PX5 shown in FIG. 4B, the width of the light-shielding portion 31 is relatively large at α, so the width (one side) W1 of the green color filter G2 2 (=P+γ-2α) 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 is thick is also relatively narrow. 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 light rays L11 to L1 2 The peripheral portion of the green color filter G2 is the peripheral portion 38 2 L,38 2 Therefore, the amount of light can be reduced by an amount greater than that proportional to the reduction in the area of ​​the green color filter G.

[0042] Both the reduction in stray light and the reduction in light intensity 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 and PX6. Therefore, the magnitude of the image signal output by each G pixel can be made roughly equal, regardless of whether the G pixel is adjacent to the focus detection pixel PX4 or 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 achieve a highly sensitive image sensor 3, it is desirable that the areas of the blue color filter B and the red color filter R be the same as the above-mentioned area S0.

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

[0045] Because 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, which may cause noise in adjacent pixels due to stray light, charge leakage, etc.

[0046] In the image sensor 3a, the area of ​​the green color filter G of the G pixel adjacent to the focus detection pixels PX14, PX16 can also be made smaller than the area of ​​the green color filter G of the G pixel not adjacent to these, thereby canceling out 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 located adjacent to PX17 on the +X side.

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

[0048] The green color filter G0, which 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 area S11 of the green color filter G1 adjacent to one of the focus detection pixels PX14, PX16 is reduced along one side due to the expansion of the focus detection color filter F, so that area S11 is smaller than the above-mentioned S10. The area S12 of the green color filter G2 adjacent to the two focus detection pixels PX14, PX16 is reduced along both sides due to the expansion of the focus detection color filter F, so that area S12 is smaller than the above-mentioned S11. This makes it possible to reduce the sensitivity of the G pixels that have those green color filters G1, G2.

[0049] Therefore, by changing the areas S10, S11, and S12 of the green color filters G in accordance with the number of adjacent focus detection pixels PX14 and PX16, the increase in noise from the focus detection pixels PX14 and PX16 can be offset by the decrease in sensitivity due to the reduction in area, thereby making it possible to make the magnitude of the image signal output by each G pixel roughly equal, regardless of whether the G pixel is adjacent to the focus detection pixel PX14 or PX16.

[0050] Furthermore, the reduction in the amount of light due to the substantial increase in the thickness of the green color filter G described in the 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 the pixel PX11 in FIG. 5, and FIG. 6(b) is an enlarged cross-sectional view of the pixel PX15 in FIG. In FIGS. 6(a) and 6(b), similarly to FIGS. 4(a) and 4(b), only the microlenses 36 and the color filters CF are enlarged and shown. 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 formed by the focus detection color filter F and the blue color filter B, and therefore, 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. 6(a), the width W20 (=P) of the green color filter G0 is relatively large. Therefore, the distance between the thicker peripheral portions 390L and 390R of the green color filter G0 is also relatively wide. As a result, most of the light rays L11-L12 from the microlens 36 pass through the thinner central portion (region A10 having a thickness of approximately Tc) without passing through the thicker peripheral portions 390L and 390R of the green color filter G0.

[0053] On the other hand, in the case of pixel PX15 shown in FIG. 6(b), the width W21 (=2P-δ) of the green color filter G2 is relatively small. Therefore, the distance 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. 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 light rays L11 to L1 2 The peripheral portions of the green color filter G2 pass through the thick peripheral portions 392L and 392R of the green color filter G2, and more light is absorbed by the green color filter G2, reducing the amount of light. Therefore, 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 simply by increasing or decreasing the area of ​​the green color filter G and the area of ​​the focus detection color filter F. However, the above-mentioned substantial increase or decrease in the thickness of the green color filter G, which occurs additionally when the focus detection color filter F and the green color filter G have the same spectral transmission characteristics, can increase or decrease the sensitivity of the G pixel.

[0055] In the second embodiment, too, if 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 and 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 and Y directions, and the length of one side of the pixels PX and the color filters CF may also be different in the X and Y directions. Furthermore, the pixels PX arranged adjacent to the focus detection pixels PX14 and PX16 are not necessarily limited to the G pixels described above, but may be pixels that are relatively sensitive to light other than green. Furthermore, the photoelectric conversion unit PD is not limited to a photodiode made of silicon, but may be a photodiode made of an organic film or a photoresistor. Moreover, the imaging device of the above-described embodiment may be provided with 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 perspective, the image sensor 3, 3a of the first or second embodiment includes a first pixel (G pixel) having a first transparent film G that transmits light in a first wavelength range, and a second pixel (focus detection pixel) having a second transparent film F that transmits light in a second wavelength range, and is configured such that 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 first transparent film G of the first pixel (G pixel) not adjacent to the second pixel (focus detection pixel). 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 reduces the variation in image signal magnitude that previously occurred in pixels near focus detection pixels, making it possible to output a more uniform, high-quality image signal.

[0058] (2) By configuring the area of ​​the first transparent film G of a first pixel (G pixel) adjacent to two second pixels (focus detection pixels) to be smaller than the area of ​​the first transparent film G of a first pixel (G pixel) adjacent to one second pixel (focus detection pixel), the magnitude of the image signal output by each first pixel (G pixel) can be made approximately 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 any second pixels (focus detection pixels). (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 film B, R, thereby reducing the variation in the magnitude of the image signals output by the first pixel (G pixel) and 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 and 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 and R pixel).

[0059] (5) From a second perspective, the image sensor 3, 3a of the first or second embodiment comprises a first pixel (G pixel) having a first transmissive film G that transmits light in a first wavelength range and has an area (A0, A2, A10, A12) with 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) adjacent to the second pixel (focus detection pixel) is narrower than the area (A0, A10) of the first pixel (G pixel) not adjacent to the second pixel (focus detection pixel). With this configuration, in the first pixel (G pixel) adjacent to the second pixel (focus detection pixel), the light rays L11 to L1 2 The peripheral portion of the first permeable membrane G is a peripheral portion 38 having a different thickness. 2 L,38 2 R,3 9 2L,3 9 Since the light passes through 2R and the amount of light absorbed by the first transmission film G varies, the amount of image signal to be output can be increased or decreased.

[0060] (6) By configuring the area of ​​a first pixel (G pixel) adjacent to two second pixels (focus detection pixels) to be narrower than the area of ​​a first pixel (G pixel) adjacent to one second pixel (focus detection pixel), the magnitude 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 any second pixels (focus detection pixels). (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) 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) not adjacent to a second pixel (focus detection pixel).

[0061] (8) From a third perspective, the image sensor 3 of the first embodiment includes a first pixel (G pixel) having a first transparent film G that transmits light in a first wavelength range, a second pixel (focus detection pixel) having a second transparent film F that transmits light in a second wavelength range, a third pixel having third transparent 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 transparent film G and the second transparent film F, and a second light-shielding portion 31 between the first transparent film G and the third transparent 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 reduces the variation in image signal magnitude that previously occurred in pixels near focus detection pixels, making it possible to output a more uniform, high-quality image signal. (9) The first pixel (G pixel) receives light in a first wavelength range from the light that has passed through the optical system and outputs a signal used to generate an image, and the second pixel (focus detection pixel) receives light in a second wavelength range from the light that has passed through the optical system and outputs a signal used for focus detection in the optical system. This configuration makes it possible to obtain an output signal from the first pixel (G pixel) adjacent to the second pixel (focus detection pixel) that is not affected by noise caused by the second pixel (focus detection pixel) (noise is canceled out). This also has the effect of further increasing the degree of freedom in the placement of the second pixel (focus detection pixel).

[0062] (10) The second transparent film F is configured to transmit light in a wavelength range that includes at least the first wavelength range, thereby enabling 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 variations in the magnitude of image signals that conventionally occur 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. Furthermore, each embodiment and modification may be applied independently or in combination. Other aspects conceivable within the scope of the technical concept of the present invention are also included within the scope of the present invention. [Explanation of symbols]

[0065] 1: imaging device, 2: imaging lens, 3: imaging element, 4: control unit, 5: lens moving unit, PX: pixel 30, G0, G1, G2: green color filter, B: blue color filter, R: red color filter, F: focus detection color filter, 31: light blocking 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 transmission 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 on the opposite side to the first surface having a third region facing the first region and a fourth region facing the second region; 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 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; 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; a shielding portion that shields a portion of light incident on the second photoelectric conversion portion; Equipped with The first transmission film and the first photoelectric conversion unit are each provided in a plurality of parts, an area of ​​the first region of the first permeable membrane adjacent to at least one of the second permeable membranes is smaller than an area of ​​the first region of the first permeable membrane not adjacent to the second permeable membrane; 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, The first permeable membrane is formed such that the second region rises higher than the first region in a direction from the second surface toward the first surface. Image sensor.

2. The first transmission film and the second transmission film have different transmission wavelength ranges. The imaging device according to claim 1 .

3. 3. The imaging device according to claim 1, 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. The imaging device 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. The imaging device according to any one of claims 1 to 4, The second surface of the imaging element is flat.

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

8. The imaging device according to claim 6 or 7, 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.

9. The imaging device according to any one of claims 1 to 8, The second photoelectric conversion unit is an image sensor arranged adjacent to the first photoelectric conversion unit in the row direction.

10. The imaging device according to any one of claims 1 to 9, The imaging element, wherein the second surface and the fourth surface are flat.

11. The imaging device according to any one of claims 1 to 10, 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 fifth regions arranged adjacent to the first region increases.

12. The imaging device according to any one of claims 1 to 11, 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.

13. The imaging device according to any one of claims 1 to 12, an imaging element having a light blocking portion between the first transparent film and the second transparent film;

14. The imaging device according to claim 13, 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.

15. The imaging device according to claim 13 or 14, 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.

16. The imaging device according to any one of claims 13 to 15, 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.

17. The imaging device according to any one of claims 1 to 16, 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;

18. The imaging element according to any one of claims 1 to 17, a generation unit that generates image data based on a signal from the imaging element.

Images