Image sensor, camera module, electronic device, and display system

Abstract

Embodiments of the present application provide an image sensor, a camera module, an electronic device, and a display system. The image sensor comprises a metasurface layer and a photoelectric conversion layer which are stacked. The photoelectric conversion layer is used for converting light passing through the metasurface layer into an electric signal. The metasurface layer is provided with a first micro / nanostructure layer. The first micro / nanostructure layer comprises a plurality of microstructure arrays. Each microstructure array comprises a plurality of structural units arranged in an array, and the structural units of at least two microstructure arrays have different structures. The photoelectric conversion layer is provided with a plurality of photosensitive areas, and the plurality of photosensitive areas have one-to-one correspondence to the plurality of structural units of the metasurface layer. The image sensor, camera module, electronic device, and display system provided by the embodiments of the present application can improve the quality of images.

Description

Image sensors, camera modules, electronic devices and display systems Technical Field

[0001] The present application relates to the field of optical imaging technology, and in particular to an image sensor, a camera module, an electronic device, and a display system. Background Art

[0002] An image sensor is a device that can convert an optical image into an electrical signal and is widely used in electronic devices such as mobile phones, digital cameras, tablet computers, and webcams. Taking the application of image sensors in digital cameras as an example, the digital camera uses a lens group to image the optical image on the image sensor. The image sensor converts the optical signal of the image into an analog electrical signal and inputs it into the digital camera's electrical signal processor. The electrical signal processor converts the analog electrical signal into a digital signal, processes the digital signal, and outputs a photo. In related technologies, the image sensor obtains the color information of the image through a color filter, and obtains the light intensity information of the image through a photoelectric conversion element, and obtains a color image based on the light intensity information and color information. However, the images obtained by existing image sensors have the problem of low image quality, such as uneven brightness and color. Therefore, how to improve the image quality of images obtained by image sensors has become an urgent problem to be solved.

[0003] Summary of the Invention

[0004] The embodiments of the present application provide an image sensor, a camera module, an electronic device, and a display system, which can improve image quality.

[0005] The first aspect of the present application provides an image sensor, which includes a super-surface layer and a photoelectric conversion layer arranged in a stacked manner, wherein the photoelectric conversion layer is used to convert light passing through the super-surface layer into an electrical signal. The super-surface layer has a first micro-nanostructure layer, which includes a plurality of microstructure arrays, each of which includes a plurality of structural units arranged in an array, and the structures of the structural units of at least two of the microstructure arrays are different. The photoelectric conversion layer has a plurality of photosensitive areas, and the plurality of photosensitive areas correspond one-to-one to the plurality of structural units of the super-surface layer.

[0006] The first micro-nanostructure layer in the image sensor provided by the embodiment of the present application is composed of multiple microstructure arrays, and the structures of the structural units of at least two microstructure arrays are different, so that the responses of the at least two microstructure arrays to the incident light are different, that is, the refractive index or transmittance of the structural units of the at least two microstructure arrays to the incident light are different, so that the amount of light transmitted is different, and thus the amount of light received by the photosensitive areas corresponding to the structural units of different structures can be made the same, that is, the light intensity felt by the photosensitive areas is the same. Therefore, by changing the structure of the structural units in the microstructure arrays at different positions, the light intensity felt by the corresponding photosensitive areas can be changed, so that the light intensity of the corresponding parts of the image meets the requirements, and then the local or overall light intensity of the image can meet the requirements to improve the image quality. For example, by regulating the light intensity of the local area or the entire area in the image so that the overall light intensity of the image can be the same, problems such as uneven brightness and / or uneven color can be avoided.

[0007] Furthermore, because the structural units in at least two microstructure arrays differ in structure, the metasurface layer comprises structural units of various structures. Consequently, the at least two microstructure arrays operate at different angles, thereby increasing the angular range of the metasurface layer's operation and improving image quality. For example, a wide angular range of the metasurface layer's operation ensures positive brightness and color gains at the edges of the image sensor, thereby improving image quality.

[0008] In a possible implementation manner, the structures of the structural units of any two of the microstructure arrays are different.

[0009] The structures of the structural units of any two microstructure arrays in the image sensor provided by the embodiment of the present application are different, so that the structural units of different microstructure arrays respond differently to the incident light, that is, the refractive index or transmittance of the structural units of different microstructure arrays to the incident light is different, so that the amount of light passing through each microstructure array is different, and thus the light received by the photosensitive areas corresponding to the structural units of each microstructure array can be the same, so that the light intensity felt by each photosensitive area is the same. Therefore, when the structures of the structural units of each microstructure array are different, the light intensity of each area of ​​the image can be made the same, thereby further improving the image quality. In addition, since the light intensity felt by each photosensitive area is the same, the ratio of multiple colors meets the preset ratio, so that the image will not have the problem of color unevenness, thereby improving the image quality. In addition, since the structures of the structural units of different microstructure arrays are different, the working angles of each microstructure array are different, which can increase the working angle range of the super surface layer, and thus ensure that the brightness gain and color gain at the edge of the image sensor are both positive gains to improve image quality.

[0010] In one possible embodiment, the center-to-center spacings of the structural units of at least two of the microstructure arrays are different. In this case, along a direction perpendicular to the stacking direction of the metasurface layer and the photoelectric conversion layer, the center-to-center spacing refers to the spacing between the center of the structural unit and the center of the corresponding photosensitive region.

[0011] The image sensor provided in the embodiment of the present application has at least two microstructure arrays with different center-to-center spacings of structural units, so that the structural units at different positions match the main optical axis angles corresponding to the corresponding photosensitive areas, thereby better regulating light.

[0012] In one possible embodiment, the plurality of microstructure arrays include a first microstructure array and a plurality of annular second microstructure arrays, wherein the plurality of second microstructure arrays sequentially surround the first microstructure array. The center-to-center spacing of the structural units of the plurality of microstructure arrays gradually increases along a radial direction of the second microstructure array and along a direction from the first microstructure array to the second microstructure array.

[0013] In the image sensor provided by the embodiment of the present application, multiple second microstructure arrays surround the first microstructure array in sequence, and the center spacing of the structural units of the multiple microstructure arrays gradually increases from the inside to the outside, so that the distribution of each microstructure array is complementary to the relative illumination distribution formed by the halo, so that the light intensity felt by each photosensitive area is the same, thereby avoiding the appearance of halo in the image.

[0014] In a possible implementation, in the same microstructure array, the center distance between any two structural units is the same.

[0015] The image sensor provided in the embodiment of the present application can reduce the difficulty of manufacturing the super-surface layer by setting the center distance between each structural unit in the same microstructure array to be the same.

[0016] In one possible implementation, each structural unit includes multiple substructures, at least two of which have different structures, and each substructure includes multiple columnar structures. Each photosensitive region includes multiple subregions, and the multiple subregions of each photosensitive region correspond one-to-one with the multiple substructures of the corresponding structural unit. Each subregion corresponds to a color of light and is used to convert the corresponding color of light into an electrical signal.

[0017] The image sensor provided in the embodiments of the present application refracts incident light through structural units, directing light of different colors to corresponding sub-regions within the photosensitive region, thereby achieving spectroscopic separation. Furthermore, each structural unit diffracts incident light, allowing light of different colors to be transmitted to corresponding sub-regions within the corresponding photosensitive region, thereby improving light utilization efficiency.

[0018] In one possible embodiment, the image sensor further includes a color filter layer, the color filter layer being located between the metasurface layer and the photoelectric conversion layer. The color filter layer includes a plurality of color filter units arranged in an array, each of which corresponds to one of the structural units and one of the photosensitive regions. Each of the color filter units includes a plurality of color filter regions, each of which corresponds to one of the substructures and one of the subregions, and the symmetry of each color filter region is the same as that of the corresponding substructure.

[0019] The image sensor provided by the embodiment of the present application can filter the light transmitted to each sub-area of ​​the photosensitive area by setting a color filter layer between the metasurface layer and the photoelectric conversion layer, and filter out light of non-corresponding colors to avoid interference with the optical signal conversion of the photoelectric conversion layer. In other words, by further correcting the spectrum, the color of the light hitting each sub-area is the same as the color corresponding to the sub-area. In addition, by further correcting the spectrum through the color filter layer, the requirements for the back-end image processing algorithm can be reduced. In addition, by corresponding one structural unit to one color filter unit, it can be ensured that the arrangement period of the structural unit is consistent with the arrangement period of the color filter unit, ensuring that the color regulation is a periodic effect.

[0020] In addition, in the image sensor provided by the embodiment of the present application, each color filter area corresponds to a substructure and the corresponding substructure and the color filter area have the same symmetry, so that each color filter area corrects the spectrum of light passing through the corresponding substructure, thereby ensuring that the color of the light sensed by each subarea is the same as the color corresponding to the subarea.

[0021] In a possible implementation, the multiple color filter areas of each color filter unit are arranged in any one of the following arrangements: red, green, green, and blue; red, yellow, yellow, and blue; red, green, blue, and white; red, yellow, blue, and white; and cyan, yellow, yellow, and magenta.

[0022] In one possible embodiment, the image sensor further includes a second micro-nanostructure layer, disposed between the metasurface layer and the photoelectric conversion layer. The second micro-nanostructure layer includes a plurality of micro-nanounit structures, each of which includes a plurality of micro-nanostructures. Each micro-nanounit structure corresponds to one of the structural units and one of the photosensitive regions, and each micro-nanounit structure is configured to transmit light transmitted through the corresponding structural unit to the corresponding subregion of the photosensitive region.

[0023] The image sensor provided by the embodiment of the present application filters the light transmitted to each sub-region of the photosensitive area by providing a second micro-nanostructure layer between the metasurface layer and the photoelectric conversion layer, filtering out light of non-corresponding colors, thereby avoiding interference with the photoelectric conversion layer's conversion of the optical signal. In other words, by further correcting the spectrum, the color of the light hitting each sub-region is the color corresponding to that sub-region. In addition, further correcting the spectrum through the second micro-nanostructure layer can reduce the requirements for the back-end image processing algorithm.

[0024] In a possible implementation, each of the structural units is formed by at least two media with different refractive indices, and at least one of the at least two media with different refractive indices is used to form a columnar structure.

[0025] In the image sensor provided by the embodiment of the present application, each structural unit is composed of at least two media with different refractive indices, and at least one medium is used to form a columnar structure, so that each structural unit has multiple spectral channels, can diffract incident light, and achieve multiple color separation.

[0026] In a possible implementation, the super-surface layer includes a substrate layer, and the substrate layer is located between the first micro-nanostructure layer and the photoelectric conversion layer and is connected to the first micro-nanostructure layer.

[0027] In the image sensor provided in the embodiment of the present application, the first micro-nanostructure layer is connected to the substrate layer and constitutes a supersurface layer, which not only allows the various microstructure arrays to be located on the same surface to ensure the relative positions of multiple microstructure arrays, but also improves the manufacturing efficiency of the supersurface layer and the assembly efficiency of the image sensor.

[0028] In a possible embodiment, the substrate layer includes a stacked filling layer and a spacer layer, the spacer layer is located between the first micro-nanostructure layer and the filling layer, and the filling layer is used to connect to one of the color filter layer and the second micro-nanostructure layer.

[0029] The substrate layer in the image sensor provided in the embodiment of the present application is composed of a leveling layer and a spacer layer, and the spacer layer is located between the leveling layer and the first micro-nanostructure layer. It can not only connect the multiple microstructure arrays in the first micro-nanostructure layer, but also level the color filter layer or the second micro-nanostructure layer to make the surface of the substrate layer smooth.

[0030] In a possible implementation, the image sensor further includes an anti-reflection layer, and the anti-reflection layer covers the surface of the first micro-nanostructure layer.

[0031] In the image sensor provided by the embodiment of the present application, the anti-reflection layer covers the surface of the first micro-nanostructure layer, which can increase the transmittance of incident light and reduce the reflection of incident light, thereby improving light utilization.

[0032] A second aspect of the present application provides a camera module, comprising a lens and an image sensor as described in any one of the first aspects, wherein the light-emitting side of the lens faces the metasurface layer of the image sensor.

[0033] A third aspect of the present application provides an electronic device, comprising a processor and the camera module as described in the second aspect, wherein the processor is electrically connected to the image sensor of the camera module and is used to process the electrical signal output by the image sensor.

[0034] A fourth aspect of the present application provides a display system, which includes a camera device and a display device, wherein the camera device includes the camera module as described in the second aspect, and the display device is used to display information collected by the camera device. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG1 is a schematic structural diagram of an electronic device provided in an embodiment of the present application;

[0036] FIG2 is a schematic structural diagram of a camera module provided in an embodiment of the present application;

[0037] FIG3 is a schematic top view of the first micro-nanostructure layer in FIG2 ;

[0038] FIG4 is a partial schematic diagram of one of the microstructure arrays in FIG3 ;

[0039] FIG5 is a schematic diagram showing the distances between the centers of the structural units and the centers of the corresponding photosensitive regions of the different microstructure arrays in FIG3 ;

[0040] FIG6 is a schematic diagram of the edge of the first microstructure array in FIG3 ;

[0041] FIG7 is a schematic diagram showing the center offset between the structural units and the corresponding photosensitive areas of the first microstructure array in FIG3 ;

[0042] FIG8 is a schematic diagram showing the center offset between the structural units and the corresponding photosensitive areas of the second microstructure array in FIG3 ;

[0043] FIG9 is a schematic diagram showing the distance between the center of a structural unit and the center of a corresponding photosensitive area of ​​the same microstructure array in FIG3 ;

[0044] FIG10A is a schematic structural diagram of a photosensitive region and a structural unit corresponding to an embodiment of the present application;

[0045] FIG10B is a schematic diagram of a structural unit 13 in FIG3 ;

[0046] FIG11 is a schematic diagram of a partial structure of a first color filter layer provided in an embodiment of the present application;

[0047] FIG12A is a schematic diagram of a local structure centered on a blue color filter area in FIG11;

[0048] FIG12B is a schematic diagram of a local structure centered on the third substructure in FIG4 ;

[0049] FIG12C is a schematic diagram of a local structure centered on the green color filter area in FIG11;

[0050] FIG12D is a schematic diagram of a local structure centered on the red color filter area in FIG11;

[0051] FIG13A is a schematic diagram of a partial structure of a second color filter layer provided in an embodiment of the present application;

[0052] FIG13B is a schematic diagram of a local structure centered on the red color filter area in FIG13A;

[0053] FIG13C is a schematic diagram of a local structure centered on the green color filter area in FIG13A;

[0054] FIG13D is a schematic diagram of a local structure centered on the blue color filter area in FIG13A;

[0055] FIG13E is a schematic diagram of a local structure centered on the white color filter area in FIG13A;

[0056] FIG14 is a partial cross-sectional view of a first supersurface layer provided in an embodiment of the present application;

[0057] FIG15 is a partial cross-sectional view of a second supersurface layer provided in an embodiment of the present application;

[0058] FIG16 is a partial top view of a third supersurface layer provided in an embodiment of the present application;

[0059] FIG17 is a schematic structural diagram of a first photosensitive region provided in an embodiment of the present application;

[0060] FIG18 is a schematic structural diagram of a second photosensitive region provided in an embodiment of the present application;

[0061] FIG19 is a schematic diagram of another first micro-nanostructure layer provided in an embodiment of the present application, which is different from that in FIG3 ;

[0062] FIG20 is a schematic structural diagram of a second image sensor provided by an embodiment of the present application, which is different from the image sensor in FIG2 ;

[0063] FIG21 is a schematic structural diagram of a third image sensor provided in an embodiment of the present application, which is different from the image sensor in FIG2 ;

[0064] FIG22 is a schematic structural diagram of a fourth image sensor provided in an embodiment of the present application, which is different from the image sensor in FIG2 ;

[0065] FIG23 is a schematic structural diagram of a fifth image sensor provided in an embodiment of the present application, which is different from the image sensor in FIG2 .

[0066] Explanation of the accompanying drawings: 100, image sensor; 10, metasurface layer; 11, first micro-nanostructure layer; 12, microstructure array; 121, first microstructure array; 122, second microstructure array; 13, structural unit; 14, substructure; 14A, first substructure; 14B, second substructure; 14C, third substructure; 15, columnar structure; 16, substrate layer; 161, spacer layer; 162, leveling layer; 20, photoelectric conversion layer; 21, photosensitive area; 22, subregion; 23, photoelectric conversion element; 30, color filter layer; 31, color filter unit; 32, color filter area; 40, second micro-nanostructure layer; 41, micro-nanounit structure; 42, micro-nanostructure; 50, anti-reflection layer; 200, lens; 300, camera module; 400, processor; 500, electronic device. DETAILED DESCRIPTION

[0067] For ease of understanding, the technical terms involved in the embodiments of this application are explained below.

[0068] Halos, also known as vignetting, are the phenomenon where the brightness or color accuracy of the edges of a camera-generated image is different from that of the image's center. Halos can be of two types: brightness halo and color halo.

[0069] Metamaterial: In a broad sense, it refers to a complex of artificially designed unit structures with physical properties that traditional natural materials do not have. Its physical properties are mainly determined by the structure and arrangement of subwavelength (much smaller than the wavelength) unit structures.

[0070] Metasurface: A two-dimensional form of metamaterial, where the surface structure is composed of subwavelength micro-unit structures.

[0071] Chief ray angle (CRA): The angle between the chief ray of the lens and the optical axis.

[0072] Chief ray of the lens: refers to the ray passing through the center of the aperture, whose direction corresponds one-to-one with the spatial position of the image plane.

[0073] Currently, digital cameras consist of a lens assembly, an image sensor, and an electronic signal processor. The lens assembly captures an optical image on the image sensor, which then converts the image's optical signal into an analog electrical signal and feeds it into the electronic signal processor. The electronic signal processor then converts the analog signal into a digital signal, which, after data processing, outputs the image. The image sensor acquires the image's color information through a color filter array and the image's light intensity information through a photoelectric conversion element array. Combining these light intensity and color information yields a color image.

[0074] However, due to the optical principle of the lens group, the transmittance of light decreases with increasing incident angle, resulting in inconsistent brightness at the edges of the image and the center of the image, that is, the image has uneven brightness, such as brightness halo, which reduces image quality. In other words, because the center of the lens group has a much greater light-gathering ability than its edges, the light intensity at the center of the image sensor is greater than that at the surroundings, which leads to brightness halo. In addition, due to the mismatch between the main optical axis angles of the lens group and the image sensor, the spectra of light hitting different positions on the image surface are different, and the ratios of red, green and blue are also different, resulting in color halo. In addition, when the actual ratio of light intensity at various locations on the photosensitive surface of the image sensor deviates from the preset ratio, it will also lead to uneven color in various parts of the image, thereby reducing image quality. Therefore, how to improve image quality has become a problem that needs to be solved urgently.

[0075] In order to solve the brightness halo, in the related art, correction is mainly performed through the back-end image processing (ISP) algorithm, that is, the brightness distribution of the image received by the image sensor is confirmed through simulation or experiment, and then brightness compensation is performed to ensure that the image generated by the image sensor is spatially uniform. Although the problem of brightness spatial uniformity on the image plane can be solved, this is only an amplification of the signal, and the signal-to-noise ratio (SNR) difference caused by different light intensities cannot be solved by this method. Therefore, although the brightness of the image corrected by the ISP algorithm appears to be uniform, the signal-to-noise ratio at the edge of the image will still be lower than that at the center of the image. In other words, the problem of brightness halo cannot be fundamentally solved by the ISP algorithm alone.

[0076] In order to solve the problem of color halo, in related technologies, it can be solved through color correction in the ISP algorithm, that is, the color cast distribution of the image received by the image sensor is confirmed through simulation or experiment, and the color correction matrix (CCM) is adjusted in the spatial dimension to ensure the spatial consistency of the color response of the image generated by the image sensor. Although spatial correction through the color correction matrix can solve the spatial uniformity or color cast problem of image color to a certain extent, the spectrum of the light source is very complex in the actual imaging process. Correction with the color correction matrix alone will still cause serious color non-uniformity in some specific shooting scenes. In other words, it is difficult to fundamentally solve the color halo problem simply by using the ISP algorithm. Therefore, how to improve the image quality of images obtained by existing image sensors has become an urgent problem to be solved.

[0077] In view of this, embodiments of the present application provide an image sensor 100, a camera module 300, an electronic device 500, and a display system. By regulating the amount of light received by at least a portion of the photosensitive region 21, the light intensity perceived by at least that portion of the photosensitive region 21 meets the required level, thereby improving image quality. For example, by ensuring uniform light intensity across the image, defects such as uneven brightness and color can be avoided.

[0078] FIG1 is a schematic diagram of the structure of an electronic device 500 provided in an embodiment of the present application. Referring to FIG1 , the electronic device 500 provided in an embodiment of the present application includes a camera module 300 and a processor 400. The camera module 300 includes a lens 200 and an image sensor 100, and the image sensor 100 is electrically connected to the processor 400.

[0079] In one embodiment, the electronic device 500 includes a processor 400, a lens 200, and an image sensor 100. The image sensor 100 is electrically connected to the processor 400.

[0080] It should be understood that the devices included in the electronic device 500 provided in the embodiment of the present application are not limited to the devices in Figure 1. For example, the electronic device 500 provided in the embodiment of the present application may also include a battery, a flash, buttons, a screen, etc.

[0081] It should be understood that the lens 200 provided in the embodiment of the present application can be a combination of multiple lenses. Of course, the lens 200 can also include other components, for example, the lens 200 can also include a frame for supporting multiple lenses.

[0082] The electronic device 500 provided in the embodiment of the present application may include, but is not limited to, a handheld device, a wearable device (such as a smart watch), a computing device, a digital camera, a cellular phone, a smart phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, a machine type communication terminal (MTC), a point of sales (POS), an in-vehicle device, a security device, a virtual reality (VR) device, an augmented reality (AR) device, and other devices with imaging functions.

[0083] The embodiment of the present application further provides a display system, which includes a camera device and a display device. The camera device includes a camera module 300, the camera device is used to collect information with images and send the information to the display device, and the display device is used to display the information collected by the camera device.

[0084] Among them, the imaging equipment provided in the embodiments of the present application may include but is not limited to a camera, a monitor, etc.

[0085] Among them, the display device provided in the embodiment of the present application may include but is not limited to a laptop computer, a display screen, a tablet computer, a mobile phone, etc.

[0086] The image sensor 100 and the camera module 300 provided in the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0087] FIG2 is a schematic structural diagram of a camera module 300 provided in an embodiment of the present application. As shown in FIG2 , the camera module 300 provided in an embodiment of the present application includes a lens 200 and an image sensor 100. The lens 200 is used to image an optical image on the image sensor 100. The image sensor 100 includes an anti-reflection layer 50, a metasurface layer 10, a color filter layer 30, and a photoelectric conversion layer 20 stacked in sequence. The metasurface layer 10 includes a first micro-nanostructure layer 11 and a substrate layer 16 stacked in layers. The substrate layer 16 includes a spacer layer 161 and a leveling layer 62. The first micro-nanostructure layer 11 is located between the anti-reflection layer 50 and the spacer layer 161. The leveling layer 62 is located between the color filter layer 30 and the spacer layer 161.

[0088] The substrate layer 16 of the image sensor 100 provided in the embodiment of the present application is composed of a filling layer 162 and a spacer layer 161, and the filling layer 162 is located between the color filter layer 30 and the spacer layer 161. It can not only support the first micro-nanostructure layer 11, but also fill the surface of the color filter layer 30.

[0089] In one embodiment, the material of the leveling layer 162 is an organic transparent material that can be spin-coated, which can not only level the surface of the color filter layer 30 by spin coating, but also ensure high transmittance.

[0090] In one embodiment, the spacer layer 161 is made of an inorganic transparent material, such as silicon dioxide. This configuration not only connects the leveling layer 162 and the first micro-nanostructure layer 11, but also ensures high transmittance.

[0091] In the embodiment of the present application, by covering the surface of the first micro-nanostructure layer 11 with the anti-reflection layer 50, the transmittance of the incident light can be increased, the reflection of the incident light can be reduced, and thus the light utilization efficiency can be improved.

[0092] There is no particular limitation on the material of the anti-reflection layer 50. For example, the material of the anti-reflection layer 50 may include, but is not limited to, magnesium fluoride, fluorine-containing organic matter, silicon dioxide, fluorine-containing polymer, and the like.

[0093] Figure 3 is a schematic top view of the first micro-nanostructure layer 11 in Figure 2, and Figure 4 is a partial schematic view of one of the microstructure arrays 12 in Figure 3. In conjunction with Figure 2, and referring to Figures 3 and 4, the first micro-nanostructure layer 11 includes a plurality of microstructure arrays 12, each of which includes a plurality of structural units 13 arranged in an array, and the structures of the structural units 13 of any two microstructure arrays 12 are different. The photoelectric conversion layer 20 has a plurality of photosensitive regions 21, and the plurality of photosensitive regions 21 correspond one-to-one to the plurality of structural units 13 of the metasurface layer 10.

[0094] In the embodiment of the present application, as shown in FIG2 , the multiple microstructure arrays 12 of the first micro-nanostructure layer 11 are laid flat on the same surface of the substrate layer 16. In other words, along the thickness direction of the image sensor 100 or the direction in which the metasurface layer 10 and the photoelectric conversion layer 20 are stacked (such as the X direction in FIG2 ), the projections of any two microstructure arrays 12 do not overlap, and the projection of each microstructure array 12 covers part of the projection of the photoelectric conversion layer 20.

[0095] In the embodiment of the present application, the structures of the structural units 13 of any two microstructure arrays 12 are different. In other words, the structures of the two structural units 13 are different, and the two structural units 13 belong to any two microstructure arrays 12 among the multiple microstructure arrays 12. As shown in FIG3 , among any two microstructure arrays 12, the structure of the structural units 13 of one microstructure array 12 is different from the structure of the structural units 13 of the other microstructure array 12.

[0096] In the embodiment of the present application, the structural differences of the structural units 13 of any two microstructure arrays 12 may include, but are not limited to, the shape, size, etc. of the structural units 13 .

[0097] Continuing with FIG. 3 , because the structures of the structural units 13 of any two microstructure arrays 12 are different, the structural units 13 of different microstructure arrays 12 respond differently to incident light. Specifically, the structural units 13 of different microstructure arrays 12 have different refractive indices or transmittances of incident light, resulting in different amounts of light passing through the structural units 13 of different microstructure arrays 12. As a result, the amounts of light received by each photosensitive region 21 can be the same or nearly the same, and thus, the light intensity perceived by each photosensitive region 21 can be the same or nearly the same. Therefore, under the premise that the light intensity perceived by each photosensitive region 21 is the same, the light intensity at each location in the image can be the same or nearly the same, thereby maintaining consistent brightness across the image. This eliminates the problem of uneven brightness in the image, thereby improving image quality.

[0098] In addition, since the light intensity felt by each photosensitive area 21 is the same, the actual ratio of the light intensity corresponding to each color also matches the preset ratio, so that the color of each part of the image remains consistent, thereby avoiding the problem of color unevenness in the image and achieving the purpose of improving image quality.

[0099] In addition, compared with the prior art, in which the metasurface is formed by an array of structural units 13 of a single structure and has the problem of a small working angle range, the metasurface layer 10 provided in the embodiment of the present application has a plurality of structural units 13 with different structures, which can increase the working angle range of the metasurface layer 10, ensure that the brightness gain and color gain at the edge of the image sensor 100 are both positive gains, and can improve the image quality.

[0100] In summary, the metasurface layer 10 of the image sensor 100 provided in the embodiment of the present application is composed of multiple microstructure arrays 12, and the structural units 13 of each microstructure array 12 respond differently to the incident light, so that the metasurface layer 10 can regulate the amount of light received by each photosensitive area 21 of the photoelectric conversion layer 20, so that the light intensity felt by each photosensitive area 21 is the same, thereby improving the image quality.

[0101] Figure 5 is a schematic diagram of the distance between the center of the structural unit 13 of the different microstructure arrays 12 in Figure 3 and the center of the corresponding photosensitive area 21. In the embodiment of the present application, referring to Figure 5, the multiple microstructure arrays 12 of the first micro-nanostructure layer 11 include a first microstructure array 121 and a plurality of second microstructure arrays 122 in a ring shape. Among them, the multiple second microstructure arrays 122 surround the first microstructure array 121 in sequence. Along the radial direction of the second microstructure array 122 and in the direction from the first microstructure array 121 to the second microstructure array 122, the center distance between the structural units 13 of the multiple microstructure arrays 12 gradually increases. Along the direction perpendicular to the direction in which the supersurface layer 10 and the photoelectric conversion layer 20 are stacked, the center distance refers to the distance between the center of the structural unit 13 and the center of the corresponding photosensitive area 21.

[0102] Accordingly, in the image sensor 100 provided in the embodiment of the present application, the plurality of second microstructure arrays 122 sequentially surround the first microstructure array 121, and the center-to-center spacing of the structural units 13 of the plurality of microstructure arrays 12 gradually increases, so that the overall distribution of the plurality of microstructure arrays 12 complements the relative illumination distribution formed by haloing. Therefore, under the condition that the structural units 13 of each microstructure array 12 respond differently to incident light, the light intensity perceived by each photosensitive area 21 is the same, thereby preventing the occurrence of haloing in the image.

[0103] In the embodiment of the present application, the center-to-center spacing of the structural units 13 of the plurality of microstructure arrays 12 gradually increases along the radial direction of the second microstructure array 122 and in the direction from the first microstructure array 121 to the second microstructure array 122. Referring to FIG5 , along the radial direction of the first microstructure array 121 or the radial direction of the second microstructure array 122, from the center of the first microstructure array 121 outward, the center-to-center spacing of the structural units 13 of the plurality of microstructure arrays 12 gradually increases. In other words, along the radial direction of the first microstructure array 121, the center-to-center spacing of any structural unit 13 in one of the two adjacent microstructure arrays 12 is smaller than the center-to-center spacing of any structural unit 13 in the other microstructure array 12, and the outer diameter (or diameter) of one of the microstructure arrays 12 is smaller than the outer diameter of the other microstructure array 12. It is understandable that when the first microstructure array 121 is one of the microstructure arrays 12, one of the microstructure arrays 12 is circular, so that the diameter of one of the microstructure arrays 12 is smaller than the outer diameter of the other microstructure array 12.

[0104] As shown in FIG5 , the first microstructure array 121 is circular, and the second microstructure array 122 is annular. Of course, the shape of the first microstructure array 121 is not limited to a circle and can be, for example, a rectangle. Similarly, the shape of the second microstructure array 122 is not limited to annular; for example, the second microstructure array 122 can be a rectangular ring structure.

[0105] As shown in FIG5 , the first microstructure array 121 is circular. However, this does not mean that the edges of the first microstructure array 121 are circular as shown in FIG5 . Instead, they are quasi-circular as shown in FIG6 . The dashed line M in FIG6 represents the boundary of the first microstructure array 121 in FIG5 . Similarly, when the second microstructure array 122 is annular, this does not mean that the inner and outer edges of the second microstructure array 122 are circular as shown in FIG5 . They can also be quasi-circular, as shown in FIG6 .

[0106] In the embodiment of the present application, the center-to-center distance of the structural units 13 can be determined by the relationship shift=d*tan(CRA).

[0107] FIG7 is a schematic diagram showing the center offset of the structural units 13 of the first microstructure array 121 and the corresponding photosensitive regions 21 in FIG3 . Referring to FIG3 and FIG7 , it can be seen that the principal optical axis angle corresponding to the structural units 13 in the first microstructure array 121 is 0°, so that in a direction perpendicular to the direction in which the metasurface layer 10 and the photoelectric conversion layer 20 are stacked, the spacing between the centers of the structural units 13 of the first microstructure array 121 and the centers of the corresponding photosensitive regions 21 is 0, i.e., the center-to-center spacing of the structural units 13 is 0.

[0108] FIG8 is a schematic diagram illustrating the center offset between the structural units 13 of the second microstructure array 122 and the corresponding photosensitive regions 21 in FIG3 . Referring to FIG3 and FIG8 , it can be seen that the distance between the center of each structural unit 13 of the second microstructure array 122 and the center of the corresponding photosensitive region 21 is calculated using the above relationship: shift = d * tan(CRA).

[0109] Therefore, the center-to-center spacing of each structural unit 13 can be determined by the relationship: shift = d*tan(CRA), where shift is the center-to-center spacing of the structural units 13, d is the thickness of the metasurface layer 10 in the thickness direction of the image sensor 100, and CRA is the principal optical axis angle corresponding to each structural unit 13 (or the photosensitive area 2 corresponding to each structural unit 13).

[0110] Figure 9 is a schematic diagram of the distance between the center of the structural unit 13 and the center of the corresponding photosensitive area 21 of the same microstructure array 12 in Figure 3. In the embodiment of the present application, as shown in Figure 9, in the same microstructure array 12, the center distance between any two structural units 13 is the same.

[0111] However, in one embodiment, in the same microstructure array 12 and along the radial direction of the microstructure array 12 , the center distances between two adjacent structure units 13 are different (not shown in the figure).

[0112] Since the overall shape of the first micro-nanostructure layer 11 is circular, and combined with the relationship: shift = d*tan(CRA) and Figure 2, it can be seen that along the radial direction of the first micro-nanostructure layer 11, the main optical axis angle corresponding to each structural unit 13 is different. Specifically, the main optical axis angle gradually changes from the inside to the outside along the radial direction of the first micro-nanostructure layer 11 from the center of the circle. Therefore, in the same microstructure array 12, if the center distances between two adjacent structural units 13 are set to be different along the radial direction of the microstructure array 12, that is, the center distances of multiple structural units 13 gradually change along the radial direction of the first micro-nanostructure layer 11, the light can be better controlled. However, since the change in the main optical axis angle is not large, there will be multiple structural units 13 with different structures in the same microstructure array 12, which will increase the manufacturing difficulty of the supersurface layer 10. Therefore, in the same microstructure array 12, setting the center distances of all structural units 13 to be the same can not only better control the light, but also reduce the manufacturing difficulty of the supersurface layer 10.

[0113] FIG10A is a schematic diagram of a structure of a photosensitive region 21 and a structural unit 13 corresponding to an embodiment of the present application, and FIG10B is a schematic diagram of a structural unit 13 in FIG3 . In the embodiment of the present application, referring to FIG10A and FIG10B , each structural unit 13 includes a plurality of substructures 14, at least two of the plurality of substructures 14 having different structures, and each substructure 14 includes a plurality of columnar structures 15. Each photosensitive region 21 includes a plurality of subregions 22, and the plurality of subregions 22 of each photosensitive region 21 correspond one-to-one to the plurality of substructures 14 of the corresponding structural unit 13. Each subregion 22 corresponds to a color of light and is used to convert the corresponding color of light into an electrical signal.

[0114] Accordingly, the image sensor 100 provided in the embodiment of the present application refracts incident light through the structural units 13, causing light of different colors to be refracted to corresponding sub-regions 22 within the photosensitive region 21, thereby achieving light separation. Furthermore, each structural unit 13 diffracts the incident light, allowing light of different colors to be transmitted to corresponding sub-regions 22 within the corresponding photosensitive region 21, thereby improving light utilization efficiency.

[0115] It should be understood that each sub-region 22 corresponds to light of one color, which means that each sub-region 22 is used to receive light of one color and convert the light signal of the corresponding color into an electrical signal.

[0116] It should be understood that the colors of light corresponding to the multiple sub-regions 22 of each photosensitive region 21 may include, but are not limited to, red, yellow, green, blue, white, etc. Furthermore, the colors of light corresponding to the multiple sub-regions 22 of each photosensitive region 21 may be partially the same. In other words, the colors of light corresponding to some of the multiple sub-regions 22 of each photosensitive region 21 may be the same, while the colors of light corresponding to other sub-regions 22 may be different. Alternatively, the colors of light corresponding to the multiple sub-regions 22 of each photosensitive region 21 may be different.

[0117] In the embodiment of the present application, the multiple sub-regions 22 of each photosensitive region 21 can be arranged in an RGGB (red, green, green, blue), RYYB (red, yellow, yellow, blue), or RGBW (red, green, blue, white) arrangement. For example, each photosensitive region 21 includes four sub-regions 22, two of which are used to receive green light, and one of the remaining two sub-regions 22 is used to receive red light and the other is used to receive blue light. The four sub-regions 22 are arranged in a red, green, green, blue (RGGB) arrangement.

[0118] In the embodiment of the present application, the top view shape of each columnar structure 15 in each structural unit 13 may include, but is not limited to, a triangle, a quadrilateral, or a hexagon. In addition, the shape of each columnar structure 15 in each structural unit 13 may be the same or different. In addition, the top view shape of each columnar structure 15 in each structural unit 13 is a shape that can be seamlessly spliced. Because the multiple columnar structures 15 in each structural unit 13 are similar, the multiple columnar structures 15 are spliced ​​into a larger structure. For example, the columnar structure 15 can be a cubic structure, and multiple cubic structures may be spliced ​​into a rectangular parallelepiped or other irregular shape due to their similarity.

[0119] Because each substructure 14 corresponds to a subregion 22, the number of substructures 14 in each structural unit 13 is the same as the number of colors corresponding to the subregions 22 of the corresponding photosensitive region 21. Furthermore, the arrangement of the multiple substructures 14 in each structural unit 13 is the same as the arrangement of the multiple subregions 22 of the corresponding photosensitive region 21, ensuring that the structural unit 13 transmits light of a corresponding color to the subregion 22 of the photosensitive region 21 corresponding to that color.

[0120] In the embodiment of the present application, at least two of the multiple substructures 14 of each structural unit 13 have different structures, and each substructure 14 corresponds to a subregion 22. For example, as shown in FIG10B , each structural unit 13 includes four substructures 14, two of which (such as 14B in FIG10B ) have the same structure, and the two substructures 14B have different structures from the remaining two substructures 14 (such as 14A and 14C in FIG10B ). The arrangement of the four substructures 14 is the same as the arrangement of the corresponding four subregions 22.

[0121] Since each structural unit 13 is composed of multiple substructures 14 with different structures, when refracting light of different colors, the refraction angle of light of different colors will be changed, that is, the propagation direction of light of different colors will be controlled, and then the light of different colors will be transmitted to the sub-areas 22 corresponding to the light of different colors, thereby realizing light splitting.

[0122] In the embodiment of the present application, the color filter layer 30 includes a plurality of color filter units 31 arranged in an array. Each color filter unit 31 corresponds to a structural unit 13 and a photosensitive region 21. Each color filter unit 31 includes a plurality of color filter regions 32. Each color filter region 32 corresponds to a substructure 14 and a subregion 22. The symmetry of each color filter region 32 is the same as the symmetry of the corresponding substructure 14.

[0123] Correspondingly, the image sensor 100 provided in the embodiment of the present application filters the light transmitted to each sub-region 22 of the photosensitive region 21 through the color filter layer 30, and filters out light of non-corresponding colors, thereby avoiding interference with the conversion of the light signal by the photoelectric conversion layer 20. In other words, by further correcting the spectrum, the color of the light hitting each sub-region 22 is the color corresponding to the sub-region 22. In addition, by further correcting the spectrum through the color filter layer 30, the requirements for the back-end image processing algorithm can be reduced. In addition, one structural unit 13 corresponds to one color filter unit 31, which can ensure that the arrangement period of the structural unit 13 is consistent with the arrangement period of the color filter unit 31, ensuring that the color regulation is a periodic effect.

[0124] In addition, by making the symmetry of each color filter region 32 the same as the symmetry of the corresponding substructure 14, it is ensured that light passing through each substructure 14 can be transmitted to the corresponding color filter region 32. For example, red light passing through the substructure 14 can be transmitted to the corresponding color filter region 32, so that the red subregion 22 can receive the red light.

[0125] In the embodiment of the present application, each color filter region 32 covers the corresponding sub-region 22 along the thickness direction of the image sensor 100, thereby ensuring that light of a certain color is filtered and that the sub-region 22 receives light of the corresponding color. For example, if the light corresponding to the sub-region 22 corresponding to the color filter region 32 is red, the color filter region 32 can only transmit the light of the color filter and filter light of other colors except red.

[0126] In the embodiment of the present application, each color filter region 32 includes a color filter, so that each color filter unit 31 includes a plurality of color filters arranged in an array, and the color filter layer 30 is formed by arranging a plurality of color filters in an array.

[0127] In the embodiment of the present application, the arrangement of the multiple color filter areas 32 of each color filter unit 31 may include but is not limited to red, green, green, blue (RGGB), red, yellow, yellow, blue (RYYB), red, green, blue, and white (RGBW), red, yellow, blue, and white (RYBW), cyan, yellow, yellow, magenta (CYYM), etc.

[0128] In the embodiment of the present application, the arrangement of the multiple color filter areas 32 of the color filter unit 31 is one of the arrangements such as red, green, green, and blue (RGGB), red, yellow, yellow, and blue (RYYB), red, green, blue, and white (RGBW), red, yellow, blue, and white (RYBW), and cyan, yellow, yellow, magenta (CYYM). However, in some embodiments, the arrangement of the color filter areas 32 in the color filter layer 30 may also include but is not limited to two or three. For example, the arrangement corresponding to some of the color filter units 31 in the multiple color filter units 31 is red, green, green, and blue, and the arrangement corresponding to some of the color filter units 31 is red, yellow, blue, and white.

[0129] In the embodiment of the present application, after the arrangement of the multiple color filter regions 32 of each color filter unit 31 is determined, the symmetry of each color filter region 32 is also determined. At the same time, the symmetry of the substructure 14 corresponding to each color filter region 32 is also determined.

[0130] The following describes, with reference to the accompanying drawings, an example of how to determine the symmetry of the substructure 14 according to the arrangement of the multiple color filter regions 32 of the color filter unit 31 .

[0131] FIG11 is a schematic diagram of a partial structure of a first color filter layer 30 provided in an embodiment of the present application. In one embodiment, FIG11 shows that each color filter unit 31 includes four color filter regions 32, and the four color filter regions 32 are arranged in a red-green-green-blue (RGGB) pattern. Correspondingly, as shown in FIG10B , each structural unit 13 includes four substructures 14, each of which includes a first substructure 14A, a second substructure 14B, and a third substructure 14C. The first substructure 14A corresponds to the color filter region 32 receiving red, the second substructure 14B corresponds to the color filter region 32 receiving green, and the third substructure 14C corresponds to the color filter region 32 receiving blue.

[0132] Figure 12A is a schematic diagram of the partial structure of Figure 11 centered around the blue filter region 32. As shown in Figure 12A , green filter regions 32 are located directly above, below, to the left, and to the right of the blue (B) region, and red filter regions 32 are located at all four diagonal corners. Folding the figure shown in Figure 12A in half along symmetry axes a1, a2, a3, and a4, the blue filter region 32 exhibits the following symmetry: symmetry about four intersecting axes, with the angle between two adjacent axes of symmetry being 45°. Therefore, the symmetry of the substructure 14 in the structural unit 13 corresponding to the blue filter region 32 is also determined. As shown in Figure 12B , the third substructure 14C is symmetric about the axes of symmetry a1, a2, a3, and a4. Figure 12B is a schematic diagram of the partial structure of Figure 4 centered around the third substructure 14C.

[0133] Figure 12C is a schematic diagram of the partial structure of Figure 11 centered around the green filter region 32. As shown in Figure 12C , blue filter regions 32 are located directly above and below the blue (B) region, red filter regions 32 are located directly to the left and right, and green filter regions 32 are located at all four diagonal corners. Folding the diagram shown in Figure 12C in half along symmetry axes a1, a2, a3, and a4, the green filter region 32 exhibits the following symmetry: symmetry about two intersecting axes, with the angle between the two axes being 90°. Therefore, the symmetry of the substructure 14 corresponding to the green filter region 32 in the structural unit 13 is also determined.

[0134] Figure 12D is a schematic diagram of the partial structure of Figure 11 centered around the red filter region 32. As shown in Figure 12D , green filter regions 32 are located directly above, below, to the left, and to the right of the blue (B) region, and blue filter regions 32 are located at all four diagonal corners. Folding the diagram shown in Figure 12D in half along symmetry axes a1, a2, a3, and a4, the green filter region 32 exhibits the following symmetry: symmetry about four intersecting axes, with the angle between two adjacent axes of symmetry being 45°. Therefore, the symmetry of the substructure 14 corresponding to the red filter region 32 in the structural unit 13 is also established.

[0135] In summary, when the arrangement of the multiple color filter regions 32 of the color filter unit 31 is RGGB, the red and blue color filter regions 32 are symmetrical about four symmetry axes and the angle between two adjacent symmetry axes of the four symmetry axes is 45°, and the green color filter region 32 is symmetrical about two symmetry axes with an angle of 90 degrees.

[0136] Figure 13A is a schematic diagram of the structure of the second color filter layer provided in an embodiment of the present application. In one embodiment, as can be seen from Figure 13A, the color filter layer 30 includes multiple color filter groups, each color filter group includes four color filter units 31, and the four color filter units 31 are arranged in red, green, blue, and white (RGBW). Each color filter unit 31 includes four color filter regions 32, and the arrangement of the four color filter regions 32 is one of RWWR, GWWG, and BWWB. Correspondingly, each structural unit 13 includes four substructures 14, and each substructure 14 corresponds to a color filter region 32 of a color.

[0137] Figure 13B is a schematic diagram of the partial structure of Figure 13A centered around the red filter region 32. As shown in Figure 13B , white filter regions 32 are located directly above, below, to the left, and to the right of the red (R) region. The two filter regions 32 at one diagonal corner are both green, while the two filter regions 32 at the other diagonal corner are blue and red, respectively. Folding the diagram shown in Figure 13B in half along symmetry axes a1, a2, a3, and a4, the red filter region 32 exhibits symmetry about the first diagonal line (a2). Therefore, the symmetry of the substructure 14 corresponding to the red filter region 32 in the structural unit 13 is also determined.

[0138] Figure 13C is a schematic diagram of the partial structure of Figure 13A centered around the green filter region 32. As shown in Figure 13C , white filter regions 32 are located directly above, below, to the left, and to the right of the red (R) region. The two filter regions 32 at one diagonal corner are both green, while the two filter regions 32 at the other diagonal corner are blue and red, respectively. Folding the diagram shown in Figure 13C in half along symmetry axes a1, a2, a3, and a4, the red filter region 32 exhibits symmetry about the second diagonal line (a4). Therefore, the symmetry of the substructure 14 corresponding to the green filter region 32 in the structural unit 13 is also determined.

[0139] Figure 13D is a schematic diagram of the partial structure of Figure 13A centered around the blue filter region 32. As shown in Figure 13D , white filter regions 32 are located directly above, below, to the left, and to the right of the red (R) region. The two filter regions 32 at one diagonal corner are both green, while the two filter regions 32 at the other diagonal corner are blue and red, respectively. Folding the diagram shown in Figure 13D in half along symmetry axes a1, a2, a3, and a4, the red filter region 32 exhibits symmetry about the first diagonal line (a2). Therefore, the symmetry of the substructure 14 corresponding to the blue filter region 32 in the structural unit 13 is also determined.

[0140] Figure 13E is a schematic diagram of the partial structure of Figure 13A centered around the white filter region 32. As shown in Figure 13E , green filter regions 32 are located directly above and to the right of the red (R) region, blue filter regions 32 are located directly below and to the left, and white filter regions 32 are located at the four corners. Folding the diagram shown in Figure 13E in half along symmetry axes a1, a2, a3, and a4, the red filter region 32 exhibits symmetry about the second diagonal line (a4). Therefore, the symmetry of the substructure 14 corresponding to the white filter region 32 in the structural unit 13 is also determined.

[0141] In summary, when the arrangement of the multiple color filter regions 32 of the color filter unit 31 is RGBW, the red and blue color filter regions 32 are symmetrical about the first diagonal line, and the white and green color filter regions 32 are symmetrical about the second diagonal line. The first diagonal line and the second diagonal line are perpendicular and compared to a point.

[0142] Therefore, after the arrangement of the color filter layer 30 is determined, the symmetry of the color filter region 32 can be determined by selecting the corresponding color filter region 32 and a circle of color filter regions 32 surrounding the color filter region 32 .

[0143] In the embodiment of the present application, each structural unit 13 is formed by at least two media with different refractive indices, and at least one of the at least two media with different refractive indices is used to form the columnar structure 15 .

[0144] Accordingly, each structural unit 13 in the image sensor 100 provided in the embodiment of the present application is composed of at least two media with different refractive indices, and at least one medium is used to form a columnar structure 15, so that each structural unit 13 has multiple spectral channels, which can diffract the incident light and thus separate multiple colors.

[0145] In the embodiment of the present application, the material of the medium may include but is not limited to titanium dioxide, gallium nitride, silicon nitride, air or vacuum.

[0146] In the embodiment of the present application, the types and quantities of media in each structural unit 13 are the same, which can reduce the difficulty of manufacturing the metasurface layer 10. Of course, in some embodiments, the types and quantities of media included in each structural unit 13 can also be different.

[0147] FIG14 is a partial cross-sectional view of the first metasurface layer 10 provided in an embodiment of the present application. In one embodiment, as shown in FIG14 , each microstructure array 12 is formed by two media with different refractive indices (as shown in FIG14 A and B ). One of the two media forms a columnar structure 15 (as shown in FIG14 A ), and the extension direction of the columnar structure 15 is parallel to the thickness direction of the image sensor 100. The other of the two media is filled between adjacent columnar structures 15 and covers all columnar structures 15.

[0148] There is no specific limitation on the materials of the two dielectrics, and they may be, for example, silicon nitride and silicon oxide, titanium dioxide and silicon dioxide, gallium nitride and silicon dioxide, etc.

[0149] FIG15 is a partial cross-sectional view of a second metasurface layer 10 provided in an embodiment of the present application. In one embodiment, as shown in FIG15 , each microstructure array 12 is formed by two media having different refractive indices (as shown in FIG15 A and B ), and both media form columnar structures 15 , and the extension direction of the columnar structures 15 is parallel to the thickness direction of the image sensor 100 .

[0150] FIG16 is a partial top view of a third metasurface layer 10 provided in an embodiment of the present application. As shown in FIG16 , each microstructure array 12 is formed by two media having different refractive indices. For example, the microstructure array 12 can be divided into multiple grids, each of which is filled with a medium, such as titanium dioxide and air, with the titanium dioxide forming a columnar structure 15.

[0151] Continuing to refer to FIG. 16 , the size of each grid is the same. However, in one embodiment, the size of each grid may be different.

[0152] FIG17 is a schematic diagram of the structure of the first photosensitive region 21 provided in an embodiment of the present application. In the embodiment of the present application, as shown in FIG17 , each photosensitive region 21 includes multiple sub-regions 22, each sub-region 22 includes a photoelectric conversion element 23, and multiple photoelectric conversion elements 23 are arranged in an array, each photoelectric conversion element 23 is used to convert light of a corresponding color into an electrical signal.

[0153] The photoelectric conversion element 23 may include, but is not limited to, a photodiode or a charge-coupled device (CCD) in a complementary metal oxide semiconductor (CMOS).

[0154] Of course, in addition to including one photoelectric conversion element 23, each sub-region 22 may also include two or more photoelectric conversion elements 23. FIG18 is a schematic diagram of the structure of the second photosensitive region 21 provided in an embodiment of the present application. In one embodiment, as shown in FIG18 , each sub-region 22 includes two photoelectric conversion elements, so that each color filter region 32 corresponds to two photoelectric conversion elements 23.

[0155] In the above content, the first micro-nanostructure layer 11 is composed of a first microstructure array 121 and a second microstructure array 122. However, the first micro-nanostructure layer 11 can also be composed of microstructure arrays 12 of other shapes. Figure 19 is a schematic diagram of another first micro-nanostructure layer 11 provided in an embodiment of the present application, which is different from that in Figure 3. In one embodiment, the difference between Figure 19 and Figure 3 is that the first micro-nanostructure layer 11 is arranged by a plurality of rectangular microstructure arrays 12. Among them, the plurality of microstructure arrays 12 can be arranged in one dimension along the first direction, or the plurality of microstructure arrays 12 can also be arranged in two dimensions along the first direction and the second direction, and the first direction is perpendicular to the second direction.

[0156] FIG20 is a schematic structural diagram of a second image sensor 100 provided in an embodiment of the present application, which is different from the image sensor 100 in FIG2 . Referring to FIG20 , the image sensor 100 includes a supersurface layer 10 and a photoelectric conversion layer 20 arranged in a stacked manner. The supersurface layer 10 includes a substrate layer 16 and a first micro-nanostructure layer 11, with the substrate layer 16 being located between the first micro-nanostructure layer 11 and the photoelectric conversion layer 20. As can be seen from FIG2 above, the difference between FIG20 and FIG2 is that the structure of the substrate layer 16 is different, with the substrate layer 16 being a single-layer structure.

[0157] The material of the substrate layer 16 may include but is not limited to silicon dioxide, polymethyl methacrylate or polycarbonate.

[0158] Fig. 21 is a schematic structural diagram of a third image sensor 100 provided in an embodiment of the present application, which is different from the image sensor 100 in Fig. 2. The difference between Fig. 21 and Fig. 2 is that the anti-reflection layer 50 is not provided.

[0159] Figure 22 is a schematic structural diagram of a fourth image sensor 100 provided in an embodiment of the present application, which is different from the image sensor 100 in Figure 2. The difference between Figure 22 and Figure 2 is that the color filter layer 30 is replaced by a second micro-nanostructure layer 40, and the second micro-nanostructure layer 40 is used to further trim the spectrum. Specifically, the second micro-nanostructure layer 40 is arranged between the metasurface layer 10 and the photoelectric conversion layer 20. The second micro-nanostructure layer 40 includes a plurality of micro-nanounit structures 41, and each micro-nanounit structure 41 includes a plurality of micro-nanostructures 42. Each micro-nanounit structure 41 corresponds to a structural unit 13 and a photosensitive area 21, respectively. The center of each micro-nanounit structure 41 coincides with the center of the corresponding photosensitive area 21, and each micro-nanounit structure 41 is used to transmit light passing through the corresponding structural unit 13 to the sub-area 22 of the corresponding photosensitive area 21.

[0160] Accordingly, the image sensor 100 provided in the embodiment of the present application, by providing a second micro-nanostructure layer 40 between the metasurface layer 10 and the photoelectric conversion layer 20, can filter the light transmitted to each sub-region 22 of the photosensitive region 21, filtering out light of non-corresponding colors, thereby avoiding interference with the photoelectric conversion layer 20's conversion of the optical signal. In other words, by further correcting the spectrum, the color of the light hitting each sub-region 22 is the color corresponding to that sub-region 22. In addition, further correcting the spectrum through the second micro-nanostructure layer 40 can reduce the requirements for the back-end image processing algorithm.

[0161] The micro-nano structure 42 may include but is not limited to a columnar structure 15 or a pore structure.

[0162] The material of the micro-nano structure 42 may include but is not limited to dielectric materials or metal materials.

[0163] Fig. 23 is a schematic structural diagram of a fifth image sensor 100 provided in an embodiment of the present application, which is different from the image sensor 100 in Fig. 2. The difference between Fig. 23 and Fig. 2 is that the color filter layer 30 is not provided.

[0164] In the above content, the center distances between the structural units 13 of any two microstructure arrays 12 are different. However, in some embodiments, the center distances between the structural units 13 of any two microstructure arrays 12 may also be the same.

[0165] Alternatively, in one embodiment, when there are at least three microstructure arrays 12, the center-to-center spacing between the structural units 13 of at least two of the at least three microstructure arrays 12 is the same, and the center-to-center spacing between the structural units 13 of the remaining microstructure arrays 12 is different from the center-to-center spacing between the structural units 13 of the at least two microstructure arrays 12. For example, if there are four microstructure arrays 12, the center-to-center spacing between the structural units 13 of two of the microstructure arrays 12 is the same, and the center-to-center spacing between the structural units 13 of the remaining two microstructure arrays 12 is different from the center-to-center spacing between the structural units 13 of the two microstructure arrays 12.

[0166] Accordingly, by controlling the center spacing of the structural units 13 of some microstructure arrays 12 in the plurality of microstructure arrays 12 to be different, the local light can be better controlled to improve the image quality.

[0167] Among the multiple microstructure arrays 12 , the center spacings of the structural units 13 of multiple microstructure arrays 12 are different, which can be determined based on whether the main optical axis angles corresponding to the photosensitive areas 21 corresponding to the structural units 13 of each microstructure array 12 are different.

[0168] In the above description, the structures of the structural units 13 of any two microstructure arrays 12 are different. However, in one possible implementation, when the number of microstructure arrays 12 is three or more, the structures of the structural units 13 of some microstructure arrays 12 may be different, while the structures of the structural units 13 of another part of the microstructure arrays 12 may be the same, that is, the structures of the structural units 13 of at least two microstructure arrays 12 may be different.

[0169] It can be understood that at least three microstructure arrays 12 are divided into two parts, the structures of the structural units 13 of any two microstructure arrays 12 in one part are the same, the structures of the structural units 13 of any two microstructure arrays 12 in the other part are different, and the number of microstructure arrays 12 in the other part is at least two.

[0170] By making the structures of the structural units 13 of some microstructure arrays 12 in the multiple microstructure arrays 12 different, the light intensity felt by some photosensitive areas 21 in the multiple photosensitive areas 21 can be changed, thereby regulating the light intensity of some areas in the image to improve image quality.

[0171] It can be understood that when there are two microstructure arrays 12 , the structures of the structural units 13 of the two microstructure arrays 12 are different.

[0172] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An image sensor, characterized in that: It comprises a super surface layer and a photoelectric conversion layer which are stacked, wherein the photoelectric conversion layer is used to convert light passing through the super surface layer into an electrical signal, wherein: The super surface layer has a first micro-nano structure layer, the first micro-nano structure layer includes a plurality of microstructure arrays, each of the microstructure arrays includes a plurality of structure units arranged in an array, and the structures of the structure units of at least two of the microstructure arrays are different; The photoelectric conversion layer has a plurality of photosensitive regions, and the plurality of photosensitive regions correspond one-to-one to the plurality of structural units of the super-surface layer.

2. The image sensor according to claim 1, characterized in that The structures of the structural units of any two of the microstructure arrays are different.

3. The image sensor according to claim 1 or 2, characterized in that: The center distances of the structural units of at least two of the microstructure arrays are different; Among them, along the direction perpendicular to the stacking direction of the supersurface layer and the photoelectric conversion layer, the center spacing refers to the spacing between the center of the structural unit and the center of the corresponding photosensitive area.

4. The image sensor according to claim 3, characterized in that: The plurality of microstructure arrays include a first microstructure array and a plurality of second microstructure arrays in a ring shape, wherein the plurality of second microstructure arrays sequentially surround the first microstructure array, wherein: Along the radial direction of the second microstructure array and along the direction from the first microstructure array to the second microstructure array, the center spacing of the structure units of the multiple microstructure arrays gradually increases.

5. The image sensor according to any one of claims 1 to 4, characterized in that: In the same microstructure array, the center distance between any two structure units is the same.

6. The image sensor according to any one of claims 1 to 5, characterized in that: Each of the structural units includes a plurality of substructures, at least two of the substructures have different structures, and each of the substructures includes a plurality of columnar structures; Each photosensitive area includes a plurality of sub-areas, and the plurality of sub-areas of each photosensitive area correspond one-to-one to the plurality of sub-structures of the corresponding structural unit. Each of the sub-areas corresponds to light of a color and is used to convert the light of the corresponding color into an electrical signal.

7. The image sensor according to claim 6, characterized in that: The image sensor further includes a color filter layer, which is located between the metasurface layer and the photoelectric conversion layer. The color filter layer includes a plurality of color filter units arranged in an array, and each of the color filter units corresponds to one of the structural units and one of the photosensitive regions, wherein: Each of the color filter units includes a plurality of color filter regions, each of the color filter regions corresponds to one of the substructures and one of the subregions, and the symmetry of each of the color filter regions is the same as the symmetry of the corresponding substructure.

8. The image sensor according to claim 7, characterized in that: The arrangement of the multiple color filter areas of each color filter unit is any one of the following arrangements: red, green, green, and blue, red, yellow, yellow, and blue, red, green, blue, and white, red, yellow, blue, and white, and cyan, yellow, yellow, and magenta.

9. The image sensor according to claim 6, characterized in that: The image sensor further includes a second micro-nano structure layer, which is disposed between the super-surface layer and the photoelectric conversion layer, and includes a plurality of micro-nano unit structures, each of which includes a plurality of micro-nano structures; Each of the micro-nano unit structures corresponds to one of the structural units and one of the photosensitive regions, and each of the micro-nano unit structures is used to transmit light passing through the corresponding structural unit to the corresponding photosensitive region.

10. The image sensor according to any one of claims 1 to 9, characterized in that: Each of the structural units is formed by at least two media with different refractive indices, and at least one of the at least two media with different refractive indices is used to form a columnar structure.

11. The image sensor according to any one of claims 1 to 10, characterized in that: The super surface layer also includes a substrate layer, which is located between the first micro-nano structure layer and the photoelectric conversion layer and is connected to the first micro-nano structure layer.

12. The image sensor according to claim 11, characterized in that The substrate layer comprises a stacked filling layer and a spacing layer, wherein the spacing layer is located between the first micro-nano structure layer and the filling layer, and the filling layer is used to be connected to one of the color filter layer and the second micro-nano structure layer.

13. The image sensor according to any one of claims 1 to 12, characterized in that: The image sensor further includes an anti-reflection layer, and the anti-reflection layer covers the surface of the first micro-nano structure layer.

14. A camera module, characterized in that: It comprises a lens and an image sensor as described in any one of claims 1 to 13, wherein the light-emitting side of the lens faces the metasurface layer of the image sensor.

15. An electronic device, characterized in that: It comprises a processor and the camera module as claimed in claim 14, wherein the processor is electrically connected to the image sensor of the camera module and is used to process the electrical signal output by the image sensor.

16. A display system, characterized in that: It comprises a camera device and a display device, wherein the camera device comprises the camera module as claimed in claim 14, and the display device is used to display the information collected by the camera device.

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