Optical element, optical sensor, and electronic device

Abstract

The application discloses an optical element, an optical sensor and an electronic device. The optical element is arranged above a photosensitive unit, a vertical projection of the optical element covers at least a photosensitive plane of the photosensitive unit, the optical element comprises a plurality of light guide sheets arranged in sequence in a direction parallel to the photosensitive plane and a first medium layer arranged between adjacent two light guide sheets, an included angle is formed between the light guide sheet and a normal line of the photosensitive plane, the included angles of the plurality of light guide sheets and the normal line of the photosensitive plane are the same or different, a spacing is kept between adjacent two light guide sheets in the plurality of light guide sheets, the spacings between every adjacent two light guide sheets in the plurality of light guide sheets are the same or different, the light guide sheet is used for partially reflecting or totally reflecting light rays with an incident angle smaller than the included angle of the light guide sheet and the normal line of the photosensitive plane and transmitting light rays parallel to the light guide sheet, so that a light intensity distribution curve of the light rays processed by the optical element is in a bat wing shape, and the photosensitive unit is improved in responsivity to large-angle light.

Description

Technical Field

[0001] This application relates to the field of optical detection technology, and more specifically, to an optical element, an optical sensor, and an electronic device. Background Technology

[0002] An ambient light sensor (ALS) is a sensor that extracts, detects, and converts light signals of a specific wavelength. It is widely used under the screen of electronic devices to detect the intensity of ambient light and provide dimming input parameters for electronic device screens in different ambient light intensity scenarios.

[0003] As screens have evolved, their transmittance has decreased, their layering has become more complex, and their light transmission characteristics have become poorer. This makes screens more sensitive to ambient light angles, affecting the dimming sensitivity of electronic devices. Moreover, screens suffer severe attenuation of light incident at large angles, limiting the light-receiving angle of ambient light sensors. When ambient light is incident on the screen of an electronic device at a large angle, the ambient light sensor is less sensitive to large-angle light, so even in strong ambient light scenarios, the dimming logic of the electronic device will be triggered, resulting in a poor screen user experience. Utility Model Content

[0004] This application provides an optical element, an optical sensor, and an electronic device to solve the above-mentioned problems.

[0005] To achieve the aforementioned technical objectives, this application provides an optical element disposed above a photosensitive unit. The vertical projection of the optical element at least covers the photosensitive plane of the photosensitive unit. The optical element includes multiple layers of light guide sheets arranged sequentially in a direction parallel to the photosensitive plane, and a first dielectric layer disposed between two adjacent light guide sheets. The light guide sheet forms an angle with the normal to the photosensitive plane; the angles between the multiple light guide sheets and the normal to the photosensitive plane may be the same or different. The plurality of light guide sheets maintain a distance between adjacent pairs of light guide sheets, and the distance between any two adjacent pairs of light guide sheets may be the same or different. The light guide is used to partially or completely reflect light rays whose incident angle is less than the angle between the light guide and the normal of the photosensitive plane, as well as to transmit light rays parallel to the light guide, so that the light intensity distribution curve of the light after being processed by the optical element is in the shape of a batwing.

[0006] In some possible implementations, the light guide sheet includes a plurality of light guide units arranged vertically, with a spacing between adjacent light guide units in the light guide sheet, and the spacing between any two adjacent light guide units in the light guide sheet may be the same or different.

[0007] In some possible implementations, the light guide sheet further includes a second dielectric layer disposed between two adjacent light guide units.

[0008] In some possible implementations, the second dielectric layer is a transparent dielectric layer.

[0009] In some possible implementations, the number of light guiding units in each light guide sheet is at least three.

[0010] In some possible implementations, the angle between the light guide sheet and the normal to the photosensitive plane is 30° to 60°.

[0011] In some possible implementations, the angle θ between the light guide sheet and the normal of the photosensitive plane is 35°, 37° or 45°.

[0012] In some possible implementations, the reflectivity of the light guide sheet is 75-100%.

[0013] In some possible implementations, the inner surface of the light guide unit is a sloped surface, a vertical surface, an arc-shaped surface, a polygonal surface, or a wavy surface, and the outer surface of the light guide unit is a sloped surface, a vertical surface, an arc-shaped surface, a polygonal surface, or a wavy surface.

[0014] In some possible implementations, the longitudinal section of the light guide unit is rectangular or parallelogram-shaped.

[0015] In some possible implementations, the first dielectric layer is a transparent dielectric layer.

[0016] In some possible implementations, the light guide sheet has a centrally symmetrical structure.

[0017] In some possible implementations, the light guide is an annular light guide, and the cross-section of the light guide is circular, rectangular, rhomboid, or a positive even-numbered polygon.

[0018] In some possible implementations, the multiple light guides are at the same angle to the normal of the photosensitive plane, and the spacing between any two adjacent light guides is the same.

[0019] In some possible implementations, the light guide sheet has 3 to 7 layers.

[0020] In some possible implementations, the spacing between two adjacent light guide sheets is 10 μm to 40 μm.

[0021] In some possible implementations, the spacing between two adjacent light guide sheets is 10 μm, 20 μm, 30 μm or 40 μm.

[0022] In some possible implementations, the angular response bandwidth of the photosensitive unit, as well as the peak position and radian of the light intensity distribution curve of the light processed by the optical element, are changed by adjusting the angle between the light guide sheet and the normal of the photosensitive plane, the spacing between two adjacent light guide sheets, the reflectivity of the light guide sheet, the thickness of the light guide sheet, and the shape of the light guide sheet.

[0023] In some possible implementations, the optical element further includes a transparent substrate on which the plurality of light guide sheets are disposed.

[0024] In some possible implementations, the light guide sheet is made of metal.

[0025] In some possible implementations, the light guide sheet includes a substrate and a metal layer disposed on the outer surface of the substrate.

[0026] In some possible implementations, the substrate is made of at least one of silicone resin, polyimide, silica glass, or epoxy resin.

[0027] In some possible implementations, the optical element further includes a light homogenizer disposed below the plurality of light guides, the vertical projection of which at least covers the photosensitive plane.

[0028] Secondly, embodiments of this application also provide an optical sensor, including the optical element and photosensitive unit described in the first aspect, wherein the optical element is disposed above the photosensitive unit, and the vertical projection of the optical element at least covers the photosensitive plane of the photosensitive unit.

[0029] In some possible implementations, the optical element is attached to the upper surface of the photosensitive unit.

[0030] In some possible implementations, a support member is provided below the optical element to form an air gap between the optical element and the photosensitive unit. The vertical projection of the air gap at least covers the photosensitive plane of the photosensitive unit. The support member is provided on the photosensitive unit or on the periphery of the photosensitive unit.

[0031] In some possible implementations, the optical sensor further includes an encapsulation layer that encapsulates the optical element and the photosensitive unit.

[0032] Thirdly, embodiments of this application also provide an electronic device, including a screen and the optical sensor described in the second aspect, wherein the optical sensor is disposed below the screen.

[0033] The beneficial effects of this application are as follows: The optical element of this application suppresses light energy at the normal and enhances energy on both sides of the normal, processing the light into a batwing-shaped distribution. This expands the effective field of view above the photosensitive plane, improves the photosensitive unit's response to large-angle light, and when applied below the screen, reduces the screen's sensitivity to large-angle light, reduces the dimming frequency, achieves smoother dimming steps, and improves the user experience. The optical element has a wide range of material selection, low material performance requirements, and simple manufacturing process, which is conducive to mass production. Moreover, there are fewer adjustable parameters, and the parameter tolerance design has little impact on performance, resulting in more stable performance. Attached Figure Description

[0034] Figure 1 This is a schematic diagram showing the electronic device and the light source placed at different angles.

[0035] Figure 2 The curves showing the distribution of light intensity at the top and bottom of the screen when the electronic device is at different angles to the light source under a fixed light intensity.

[0036] Figure 3 This is a top view of an optical element according to an embodiment of this application.

[0037] Figure 4 This is a sectional view along line AA of an optical element according to an embodiment of this application.

[0038] Figure 5 This is a longitudinal cross-sectional view of an optical element according to another embodiment of this application.

[0039] Figure 6 This is a light intensity distribution curve of light after being processed by the optical element of this application embodiment.

[0040] Figure 7 This is a schematic diagram of the optical path of light passing through an optical element.

[0041] Figure 8 This is a longitudinal cross-sectional view of an optical element according to another embodiment of this application.

[0042] Figure 9 This is a comparison diagram of the light intensity distribution curves of light without optical element processing and light processed by the optical element according to the embodiments of this application.

[0043] Figure 10 This is a longitudinal cross-sectional view of an optical sensor according to an embodiment of this application.

[0044] Figure 11 This is a longitudinal cross-sectional view of an optical sensor according to another embodiment of this application.

[0045] Figure 12 This is a longitudinal cross-sectional view of an optical sensor according to another embodiment of this application.

[0046] Figure 13This is a longitudinal cross-sectional view of an optical sensor according to another embodiment of this application.

[0047] In the picture, 10. Optical element; 1. Light guide sheet; 11. Light guide unit; 12. Second dielectric layer; 2. First dielectric layer; 3. Transparent substrate; 4. Light homogenizer; 20. Photosensitive unit; 21. Photosensitive plane; 30. Support component; 40. Air gap; 50. Encapsulation layer; 200. Electronic device; 210. Screen; 220. Ambient light detection sensor; 230. Light shielding bracket; 300. Light source. Detailed Implementation

[0048] The under-display optical inspection system and electronic equipment provided in this application will be explained and described in detail below with reference to the accompanying drawings.

[0049] Figure 1 The diagram illustrates electronic device 200 and light source 300 positioned at different angles under the same ambient light intensity. Here, z represents the normal to screen 210. In this embodiment, the angle between the incident light and the normal to screen 210 represents the angle of the incident light, i.e., the relative tilt angle between screen 210 and light source 300. When the light shines perpendicularly onto screen 210, the incident light angle is 0°. In the diagram, the incident light angle θ2 > θ1. Combined with... Figure 2 It can be seen that the larger the relative tilt angle between the screen 210 and the light source 300 (the larger the incident light angle), the more severe the light attenuation of the screen 210, the lower the light transmittance, and the more drastic the attenuation. As a result, the ambient light detection sensor 220 below the screen 210 is particularly sensitive to the incident light angle when detecting ambient light intensity. Even a slight change in the relative tilt angle between the electronic device 200 and the light source 300 will trigger the electronic device 200 to dim, resulting in a poor user experience.

[0050] The dimming logic of screen 210 is linearly related to the light intensity of ambient light detection sensor 220. In practical applications, the ambient light intensity is relatively stable, and the light intensity of ambient light detection sensor 220 is mainly affected by the angle of incident light entering ambient light detection sensor 220.

[0051] In practical applications, the ambient light detection performance of the ambient light sensor 220 is more accurate when the intensity of the received light is more than half the intensity of the light at an incident angle of 0° (i.e., the light at the normal). This intensity of light is called the effective light. On the light intensity distribution curve, the angular range of light with an intensity half that of the light at the normal is called the half-power angle. Therefore, in practical applications, the half-power angle is usually used as the application scenario for light detection, and it is also used as the dimming threshold of the screen 210.

[0052] Based on this, this embodiment specifically discloses an optical element 10, which is disposed above the photosensitive unit 20. In this embodiment, the photosensitive unit 20 is used to detect the intensity of ambient light, and the photosensitive unit 20 can be at least one photodiode. The vertical projection of the optical element 10 at least covers the photosensitive plane 21 of the photosensitive unit 20. The edge of the vertical projection of the optical element 10 coincides with the edge of the photosensitive plane 21, or the photosensitive plane 21 is within the vertical projection of the optical element 10, so that the photosensitive plane 21 of the photosensitive unit 20 receives a sufficient amount of effective light processed by the optical element 10.

[0053] In this embodiment, the photosensitive plane 21 of the photosensitive unit 20 is horizontally arranged, and the optical element 10 is also horizontally arranged. The vertical direction refers to the direction perpendicular to the photosensitive plane 21.

[0054] Please see Figure 3-5 The optical element 10 includes multiple light guide sheets 1 arranged sequentially in a direction parallel to the photosensitive plane 21 and a first dielectric layer 2 disposed between two adjacent light guide sheets 1. The light guide sheets 1 form an angle θ with the normal of the photosensitive plane 21 (that is, the light guide sheets 1 have an inclined angle in the direction perpendicular to the photosensitive unit 20). The angles between the multiple light guide sheets 1 and the normal of the photosensitive plane 21 may be the same or different.

[0055] Multiple light guides 1 form a louver-like design. The light guides 1 are not limited to sheet-like, ring-shaped (e.g., circular, square), or any regular shape.

[0056] It should be understood that the ring described in the embodiments of this application is a generally circular shape, rather than strictly requiring its structure to be closed.

[0057] In a plurality of light guide sheets 1, a distance is maintained between adjacent light guide sheets 1 so that light can enter between the light guide sheets 1 and contact the inner and outer surfaces of the light guide sheets 1, allowing the light guide sheets 1 to perform reflection, refraction, and transmission of light. The distance between any two adjacent light guide sheets 1 in the plurality of light guide sheets 1 may be the same or different.

[0058] The light guide 1 is used for partial or total reflection of light rays whose incident angle is less than the angle between the light guide 1 and the normal of the photosensitive plane 21, as well as for transmitting light rays parallel to the light guide 1, so that the light intensity distribution curve of the light after processing by the optical element 10 is batwing-shaped (e.g., Figure 6 (as shown) Figure 6 The light intensity distribution curve shown is also the light intensity distribution curve of the light incident on the photosensitive plane 21 of the photosensitive unit 20. On the light intensity distribution curve, the beam angle corresponding to the normal is 0°, and the light intensity at the normal is represented by P. The beam angle refers to the sum of the positive and negative half-axis angles. The positive and negative half-axis angles are usually the same, and the half-angle refers to the angle of either the positive or negative half-axis. The beam angle corresponding to the peak value is... Figure 6The middle represents A1~A2, the half angle is 0~A1 or 0~A2, and the light intensity of 1 / 2*P is half of the light intensity at the normal. Figure 7 This diagram illustrates the light path of light passing through optical element 10. Light rays with an incident angle smaller than the angle between the light guide 1 and the normal of the photosensitive plane 21 are partially or totally reflected, suppressing the energy of light rays at the normal and small angles, thus increasing the energy to both sides and resulting in a batwing-shaped light intensity distribution curve. Since the half-power angle is the beam angle when the light intensity is half the intensity of the light ray at the normal, the reduced light intensity at the normal effectively expands the half-power angle, thereby increasing the effective field of view angle above the photosensitive plane 21. This increases the effective light angle received by the photosensitive unit 20, improving its responsiveness to large-angle light and reducing its sensitivity to the incident light angle on the screen 210, especially large-angle light. This reduces the dimming frequency, achieving smoother dimming steps and improving the user experience. Furthermore, light rays parallel to the light guide 1 are transmitted into the photosensitive plane 21 of the photosensitive unit 20, further increasing the intensity of large-angle light and improving the responsiveness of the photosensitive unit 20 to large-angle light. Incident light rays with an angle greater than that between the light guide plate 1 and the normal of the photosensitive plane 21 are partially reflected and partially reflected multiple times before entering the photosensitive plane 21, further increasing the intensity of the large-angle light rays.

[0059] The first dielectric layer 2 enhances the support strength of the light guide sheet 1, ensuring the structural stability of the optical element 10 and the stability of its light processing capability. Light can pass through the first dielectric layer 2 into the photosensitive unit 20. When the light guide sheet 1 is sheet-shaped, the first dielectric layer 2 is also sheet-shaped; when the light guide sheet 1 is annular, the first dielectric layer 2 is also annular. The inner surface of the first dielectric layer 2 is attached to the light guide sheet 1 on its inner side, and the outer surface of the first dielectric layer 2 is attached to the light guide sheet 1 on its outer side, preventing air gaps between adjacent light guide sheets 1.

[0060] Furthermore, the first dielectric layer 2 is a transparent dielectric layer, which can be glass, SiO, or a transparent organic board. The transparent organic board can be a phenolic resin board, a PETG (polyethylene terephthalate-1,4-cyclohexanediol) board, a PMMA (polymethyl methacrylate) board, a PI (polyimide) board, or a PET (polyethylene terephthalate) board. This allows for the full projection of light parallel to the light guide 1, increasing the intensity of large-angle light and reducing sensitivity to large-angle light.

[0061] Figure 4 The light guide 1 shown is a single-level louver design, and the optical element 10 can be independent of the photosensitive unit 20 below.

[0062] Please see Figure 5The light guide sheet 1 includes multiple light guide units 11 arranged vertically. Adjacent light guide units 11 in the light guide sheet 1 are spaced apart, and the spacing between any two adjacent light guide units 11 may be the same or different. The inner surface of the first dielectric layer 2 is bonded to the light guide unit 11 on its inner side and to the second dielectric layer 12, and the outer surface of the first dielectric layer 2 is bonded to the light guide unit 11 on its outer side and to the second dielectric layer 12, thus preventing air gaps between the layers. Figure 5 The embodiment shown is a multi-level stacked louver design, in which the optical element 10 and the photosensitive unit 20 can be an integrated wafer-level design.

[0063] like Figure 5 As shown, the angle between the normal of the light guide sheet 1 and the photosensitive unit 20 is the angle between the line connecting the innermost endpoints of the multiple light guide units 11 and the normal of the photosensitive unit 20. In this embodiment, the inner side refers to the side closer to the central axis of the photosensitive unit 20, and the outer side refers to the side farther from the central axis of the photosensitive unit 20. The inner and outer edges of the multiple light guide units 11 of the light guide sheet 1 are staggered to achieve multiple spatial uniform diffusions, which can realize multi-directional coupling and improve the power diffusion peak.

[0064] In some possible implementations, such as Figure 5 As shown, the light guide sheet 1 also includes a second dielectric layer 12, which is disposed between two adjacent light guide units 11. The upper surface of the second dielectric layer 12 is attached to the light guide unit 11 above it, and the lower surface of the second dielectric layer 12 is attached to the light guide unit 11 below it, thus preventing air gaps between the light guide units 11. The second dielectric layer 12 provides support strength for the light guide units 11, ensuring the stability of the light guide sheet 1 structure and the feasibility of the manufacturing process.

[0065] In some possible embodiments, a second dielectric layer 12 may be attached below the bottom light guide unit 11 to provide protection for the light guide unit 11 and facilitate the attachment of the optical element 10 to other structures.

[0066] Furthermore, the second dielectric layer 12 is a transparent dielectric layer, through which light can pass into the light guide unit 11, and the light guide unit 11 performs reflection, transmission or refraction of the light.

[0067] Optionally, the second dielectric layer 12 is glass, SiO, or a transparent organic sheet. The transparent organic sheet can be a phenolic resin sheet, a PETG (polyethylene terephthalate-1,4-cyclohexanediol) sheet, a PMMA (polymethyl methacrylate) sheet, a PI (polyimide) sheet, or a PET (polyethylene terephthalate) sheet.

[0068] In some possible implementations, the number of light guiding units 11 in each light guide sheet 1 is at least 3, so that the light guide sheet 1 has sufficient thickness to maintain the stability of the structure and ensure the ability to process light stably.

[0069] Please see Figure 7 Taking a single-stage design with light guide 1 as an example, L2 is the dimension of the vertical projection of light guide 1 along the horizontal direction, L1 is the distance between the vertical projections of two adjacent light guides 1, and L1+L2 is the spacing between two adjacent light guides 1. By adjusting the ratio of L1 and L2, the attenuation ratio of light intensity at the normal can be adjusted, that is, the peak value and position of MAX on the light intensity distribution curve can be adjusted. By adjusting the angle between the light guide 1 and the normal of the photosensitive plane 21, the warping characteristics of the light intensity distribution curve can be adjusted, and the half-angle of the beam angle corresponding to the peak value can be adjusted. Therefore, by adjusting the angle between the light guide 1 and the normal of the photosensitive plane 21, the spacing between adjacent light guides 1, and the reflectivity of the light guide 1, the light intensity distribution curve of the light processed by the optical element 10 can be adjusted, the half-power angle can be expanded, and the response of the photosensitive unit 20 to large-angle light can be improved. The number of adjustable parameters is small, the tolerance of these parameters during manufacturing is small, the impact on performance is small, and the performance of the optical element 10 is relatively stable. It should be understood that the same principle applies to the adjustment of light guide sheet 1, which is a multi-layered design.

[0070] This application embodiment does not have requirements for the material of the light guide sheet 1, as long as the reflectivity meets the requirements. The material selection is wide, the material performance requirements are low, the manufacturing process is simple, and it is conducive to mass production.

[0071] In some possible implementations, the angle θ between the light guide 1 and the normal of the photosensitive plane 21 is 30°~60°, effectively adjusting the half-angle of the beam angle corresponding to the peak and the ratio of light intensity attenuation at the normal, thereby expanding the half-power angle and increasing the angle of effective light entering the photosensitive unit 20. The size of the angle between the light guide 1 and the normal of the photosensitive plane 21 is set according to the actual shape requirements of the light intensity distribution curve.

[0072] Preferably, the angle θ between the light guide sheet 1 and the normal of the photosensitive plane 21 is 35°, 37° or 45°, which improves the feasibility of the manufacturing process, optimizes the combined effect of light refraction and reflection, and further increases the angle of effective light entering the photosensitive unit 20.

[0073] In some possible implementations, the reflectivity of the light guide 1 is 75-100%. The reflectivity of the light guide 1 can be adjusted within this range according to the actual application requirements. This can improve directional reflection, enhance the edge coupling power of the field of view above the photosensitive unit 20, and simultaneously adjust the energy suppression capability of small-angle light and adjust the half-power angle. For a multi-level stacked design of the light guide 1, the reflectivity of the multiple light guide units 11 of each light guide 1 can be designed to be the same.

[0074] In some possible implementations, the inner surface of the light guide unit 11 is a sloped surface, a vertical surface, an arc-shaped surface, a polygonal surface, or a wavy surface, and the outer surface of the light guide unit 11 is a sloped surface, a vertical surface, an arc-shaped surface, a polygonal surface, or a wavy surface. This application does not impose any special limitations on the shape of the inner and outer surfaces of the light guide unit 11. Preferably, the longitudinal section of the light guide unit 11 is axially symmetric, meaning that the inner and outer surfaces of the light guide unit 11 have the same shape and the same light processing capability. More preferably, both the inner and outer surfaces of the light guide unit 11 are vertical surfaces.

[0075] In some possible implementations, the longitudinal section of the light guide unit 11 is rectangular or parallelogram-shaped, which improves the feasibility of the manufacturing process.

[0076] In some possible implementations, the light guide sheet 1 has a centrally symmetrical structure. Correspondingly, the light guide sheet 1 has a multi-level stacked design, and the light guide unit 11 also has a centrally symmetrical structure. This makes the light intensity distribution curve after being processed by the optical element 10 appear as a centrally symmetrical bat wing shape. The light is evenly distributed in the photosensitive plane 21 of the photosensitive unit 20, achieving stable and reliable dimming and further improving the user experience.

[0077] In some possible implementations, the light guide 1 is an annular light guide to improve the symmetry of the light intensity distribution curve after processing by the optical element 10. The cross-section of the light guide 1 is circular, rectangular, rhomboid or a regular even-numbered polygon, which improves the feasibility of the manufacturing process and enables the light intensity distribution curve after processing by the optical element 10 to be centrally symmetrical like a bat wing.

[0078] In some possible implementations, the angle θ between the multiple light guide sheets 1 and the normal of the photosensitive plane 21 is the same, and the spacing between any two adjacent light guide sheets 1 is the same, so that the light intensity distribution curve after processing by the optical element 10 is centrally symmetrical like a bat wing, and the light is evenly distributed in the photosensitive plane 21 of the photosensitive unit 20, achieving stable and reliable dimming and further improving the user experience.

[0079] In some possible implementations, the light guide sheet 1 has 3 to 7 layers, which improves the light processing capability while ensuring the stability of the structure and the stability of the light processing capability. The number of layers in the light guide sheet 1 is designed according to specific application requirements.

[0080] In some possible implementations, the spacing between two adjacent light guide sheets 1 is 10μm to 40μm, which has good light transmission capability and improves the various performances of the light intensity distribution curve.

[0081] In some possible implementations, the spacing between two adjacent light guide sheets 1 is 10μm, 20μm, 30μm or 40μm, which has good light transmission capability, improves the performance of various aspects of the light intensity distribution curve, and improves the feasibility of the manufacturing process.

[0082] In some possible implementations, the height H1 of the light guide 1 is 10μm to 100μm, and the specific height can be set according to actual needs.

[0083] In some possible implementations, the optical element 10 also includes a transparent substrate 3, on which a plurality of light guide sheets 1 are disposed, providing a substrate for the fabrication of the light guide sheets 1 and the first dielectric layer 2, and improving the structural strength and stability of the optical element 10, while facilitating bonding with other structures (such as the photosensitive unit 20).

[0084] In some possible implementations, the transparent substrate 3 is a glass plate or a transparent organic plate. The transparent organic plate can be a phenolic resin plate, PETG plate, PMMA plate, PI plate, or PET plate. It has high light transmittance, high structural strength, high heat resistance, and is easy to manufacture. UV-curable adhesive or a self-adhesive low-permeability silicone resin film layer can be used as an adhesive to bond and fix the transparent substrate 3 to the photosensitive unit 20, avoiding secondary contamination.

[0085] In some possible implementations, the light guide 1 is made of metal, which is used to reflect light and is simple to select and easy to manufacture. Correspondingly, when the light guide 1 includes multiple light guide units 11, the light guide units 11 are made of metal.

[0086] In some possible implementations, the light guide 1 is made of aluminum or silver, which has high reflectivity, good heat resistance, high rigidity and strength, simple material selection, low cost, and is easy to manufacture, and the manufacturing process is compatible with semiconductor processes. When the light guide 1 is a multi-layered design, if the material of the light guide 1 is aluminum, the material of the light guide unit 11 is aluminum; if the material of the light guide 1 is silver, the material of the light guide unit 11 is silver.

[0087] In some possible implementations, the light guide 1 includes a substrate and a metal layer disposed on the outer surface of the substrate, which reduces costs and improves the structural strength of the light guide 1. Correspondingly, when the light guide 1 includes a plurality of light guide units 11, the light guide unit 11 includes a substrate and a metal layer disposed on the outer surface of the substrate.

[0088] Furthermore, the substrate material includes at least one of silicone resin, polyimide, silica glass, or epoxy resin, which has high heat resistance, stable performance, and is not affected by subsequent chip manufacturing processes in terms of light processing capabilities.

[0089] Furthermore, the metal layer can be made of aluminum or silver, which has high reflectivity, good heat resistance, high rigidity and strength, simple material selection, low cost, easy manufacturing, and compatibility with semiconductor processes.

[0090] In some possible implementations, such as Figure 8 As shown, the optical element 10 also includes a light homogenizer 4, which is disposed below a plurality of light guide sheets 1. The vertical projection of the light homogenizer 4 covers at least the photosensitive plane 21. The light homogenizer 4 is disposed at the bottom of the optical element 10. The light homogenizer 4 is used to homogenize the light, improve the uniformity of the light distribution, solve the blue shift phenomenon that occurs in the spectrum when ambient light is incident at a large angle, and improve the user experience.

[0091] The light homogenizer 4 can adopt an existing light homogenizing structure. For example, the light homogenizer 4 has a flat upper surface and multiple protrusions on the lower surface. The protrusions can be regular or irregular in shape.

[0092] In summary, incident light is directed from the normal and various directions of the photosensitive plane 21. After multiple refractions, reflections, and spatial diffusion by the light guide sheet 1, the main optical path is guided to the optimal refraction direction by the first dielectric layer 2. Local reflection coupling enhances the power in the edge direction, achieving a batwing-shaped response curve with normal reduction and lateral enhancement. The stacked design of multiple light guide units 11 in each light guide sheet 1 achieves multiple spatial uniform diffusions, ensuring the spatial central symmetry of the light intensity distribution curve.

[0093] Statistical analysis shows that by comprehensively adjusting the spacing between the light guide sheets 1, the angle between the light guide sheet 1 and the normal of the photosensitive plane 21, and the reflectivity of the light guide sheet 1, the light intensity distribution curve after processing by the optical element 10 of this application exhibits a batwing shape, with the peak value reaching more than 170% of the intensity at the normal, and the half-angle of the beam angle corresponding to the peak value being 35°~40°. Verification shows that when using a screen 210 (such as a foldable screen) that is most sensitive to the incident light angle and has the greatest light attenuation, compared to the case without optical element 10, the optical element 10 of this application increases the half-power angle of the light incident on the photosensitive unit 20 to more than 35°, increasing the incident light angle adaptability to more than 10°, and resulting in a more uniform light intensity distribution above the photosensitive unit 20.

[0094] Figure 9 This is a comparison chart of the light intensity distribution curves of light without processing by optical element 10 and light processed by optical element 10 according to the embodiments of this application. Figure 9 (a) is a graph showing the original data of the light intensity distribution curves of light without processing by optical element 10 and after processing by optical element 10 according to the present application. Figure 9 (b) is the general Figure 9The light intensity distribution curve shown in (a) is a normalized curve with the 0° normal as the reference. In this curve, the angle between the light guide 1 and the photosensitive plane 21 is 35°, the height H1 of the light guide 1 is 30 μm, L2 is 21 μm, L1 is 18 μm, and the reflectivity of the light guide 1 is 75%. Figure 9 As can be seen, the peak value of the light intensity distribution curve of the optical element 10 after processing is 180%, the half angle of the beam angle corresponding to the peak value is about 35°, and the half power angle is about 68°.

[0095] Current mainstream Polless (depolarizer technology) screens have a small under-display field of view, with a half-power angle of approximately ±27°. This means that when the incident light angle above the screen 210 is greater than 27°, the photosensitive energy under the Polless screen decays rapidly, which is very unfriendly to the dimming algorithm of the optical sensor. The optical element 10 of this application can effectively expand the under-display field of view and reduce the curvature of optical power attenuation under the Polless screen when large-angle light is incident on the Polless screen.

[0096] The optical element 10 of this application can effectively filter direct light, stray light and accidental incident light, improve the signal-to-noise ratio and robustness of light detection, and reduce the sensitivity of the optical sensor or electronic device 200 to the direction of incident light. It is more advantageous for applications with strong changes in ambient light or hotspot shielding requirements.

[0097] Through the design of the optical element 10 in this application, the angular response bandwidth of the photosensitive unit 20, as well as the peak position and curvature of the light intensity distribution curve of the light processed by the optical element 10, are changed by adjusting the angle between the light guide sheet 1 and the normal of the photosensitive plane 21, the spacing between two adjacent light guide sheets 1, the reflectivity of the light guide sheet 1, the thickness of the light guide sheet 1, and the shape of the light guide sheet 1. By adjusting the above parameters, the customized requirements of different products and applications for the selectivity of the incident light angle can be met.

[0098] The optical element 10 of this application is fabricated based on semiconductor or MEMS (Micro-Electro-Mechanical System) technology, which is suitable for large-scale, high-consistency mass production, has good scalability, and is suitable for various applications requiring special angle response, such as backlighting, surface light source measurement, smart lighting, and consumer electronics sensing.

[0099] The optical element 10 of this application has a wide range of material options, and can be made of products with high temperature resistance, good stability, and strong high temperature resistance. It can more stably control the bat wing-shaped field of view angle above the photosensitive unit 20 and is less affected by the high temperature process introduced by the chip manufacturing process and the soldering process.

[0100] This application also provides an optical sensor, such as... Figure 10-13 As shown, the embodiment includes an optical element 10 and a photosensitive unit 20. The optical element 10 is disposed above the photosensitive unit 20, and the vertical projection of the optical element 10 at least covers the photosensitive plane 21 of the photosensitive unit 20. Mature processes such as MEMS / micro-nano lithography and polymer microforming can be used to directly fabricate the optical element 10 on the surface of the photosensitive unit 20, eliminating the need for externally added complex optical elements. This achieves deep integration, miniaturization, high consistency, and high reliability, and possesses mass production potential.

[0101] In some possible implementations, such as Figure 10 As shown, the optical element 10 is attached to the upper surface of the photosensitive unit 20, and the lower surface of the optical element 10 is attached to the upper surface of the photosensitive unit 20. The optical element 10 can be attached to the photosensitive unit 20 using a light-transmitting adhesive, preferably DAF (Die Attach Film) adhesive or water-based adhesive. This method of attaching the optical element 10 to the photosensitive unit 20 is low-cost, simple to manufacture, and easy to mass-produce.

[0102] In some possible implementations, such as Figure 11 and 12 As shown, a support member 30 is provided below the optical element 10, forming an air gap 40 between the optical element 10 and the photosensitive unit 20. The vertical projection of the air gap 40 at least covers the photosensitive plane 21 of the photosensitive unit 20. The support member 30 is disposed on the photosensitive unit 20 (e.g., Figure 11 (as shown) or disposed around the periphery of the photosensitive unit 20 (e.g. Figure 12 As shown). The optical element 10 is an independent unit, and its lower surface can be bonded and fixed to the support member 30 by an adhesive film.

[0103] Figure 11 The bottom of the support member 30 shown can be bonded and fixed to the photosensitive unit 20 with an adhesive film. Figure 12 The bottom of the support member 30 shown can be glued and fixed to the light shield bracket 230 below the screen 210. The photosensitive unit 20 is also set on the light shield bracket 230, which can be made of foam.

[0104] Figure 11 and Figure 12 The embodiment shown does not require an additional bonding process, thus reducing the impact of introduced bonding tolerances.

[0105] In the above embodiments, if there is sufficient space between the screen 210 and the photosensitive unit 20, no additional size is required, and the size of the electronic device 200 will not be changed, thus enabling miniaturization of the electronic device 200.

[0106] In some possible implementations, such as Figure 13 As shown, the optical sensor also includes an encapsulation layer 50, which encapsulates the optical element 10 and the photosensitive unit 20. The lower surface of the photosensitive unit 20 can be bonded and fixed to the light-shielding bracket 230 below the substrate or screen 210. The encapsulation layer 50 encapsulates the side of the photosensitive unit 20. The encapsulation layer 50 can be a transparent encapsulation layer, which is a transparent epoxy molding compound (EMC) layer. The optical element 10 is disposed inside the encapsulation layer 50, and the encapsulation layer 50 encapsulates the side and top of the optical element 10. The encapsulation layer 50 can also be a light-shielding encapsulation layer, with an opening corresponding to the top of the optical element 10, and a light-transmitting plate disposed inside the opening. The light-transmitting plate is preferably a transparent plate, which does not affect the amount of light entering the optical element 10. The light-shielding encapsulation layer is a black epoxy molding compound (EMC) layer or a light-absorbing material layer. The black epoxy resin molding compound layer is made of transparent EMC filled with black material. Compared with transparent EMC, it improves the coefficient of thermal expansion, thereby improving the warpage and high stress of the photosensitive unit 20 and reducing the reliability risks caused by stress. The light-shielding encapsulation layer solves the problem of light leakage from the sides of the optical element 10 and the photosensitive unit 20, eliminates the problem of light reflection inside the transparent encapsulation layer that introduces optical signal interference, improves the signal-to-noise ratio, and enhances the accuracy of optical signal recognition.

[0107] The optical element 10 in this embodiment effectively improves the uniformity and application adaptability of the light field texture, and is suitable for surface light source detection scenarios with high uniformity requirements.

[0108] This application also provides an electronic device, including a screen 210 and the optical sensor described in the above embodiments, wherein the optical sensor is disposed below the screen 210. The electronic device 200 can be a laptop, mobile phone, tablet computer, desktop computer, projector, gaming device, in-vehicle electronic device, wearable smart device, or other electronic device with a screen.

[0109] In some possible implementations, the optical element 10 may also be attached to the lower surface of the screen 210.

[0110] This application reduces the sensitivity of the screen 210 to wide-angle light by setting the optical element 10, reduces the dimming frequency, achieves a smoother dimming step, and improves the user experience.

[0111] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0112] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0113] In the description of this specification, the references to terms such as "this embodiment," "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any at least one embodiment or example. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0114] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0115] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and simple improvements made to the substantive content of this application should be included within the protection scope of this application.

Claims

1. An optical element, the optical element being disposed above a photosensitive unit, the vertical projection of the optical element at least covering the photosensitive plane of the photosensitive unit, characterized in that, The optical element includes multiple layers of light guide sheets arranged sequentially in a direction parallel to the photosensitive plane, and a first dielectric layer disposed between two adjacent light guide sheets. The light guide sheet forms an angle with the normal to the photosensitive plane; the angles between the multiple light guide sheets and the normal to the photosensitive plane may be the same or different. The plurality of light guide sheets maintain a distance between adjacent pairs of light guide sheets, and the distance between any two adjacent pairs of light guide sheets may be the same or different. The light guide is used to partially or completely reflect light rays whose incident angle is less than the angle between the light guide and the normal of the photosensitive plane, as well as to transmit light rays parallel to the light guide, so that the light intensity distribution curve of the light after being processed by the optical element is in the shape of a batwing.

2. The optical element according to claim 1, characterized in that, The light guide sheet includes multiple light guide units arranged vertically. There is a spacing between two adjacent light guide units in the light guide sheet. The spacing between any two adjacent light guide units in the light guide sheet may be the same or different.

3. The optical element according to claim 2, characterized in that, The light guide sheet further includes a second dielectric layer, which is disposed between two adjacent light guide units.

4. The optical element according to claim 3, characterized in that, The second dielectric layer is a transparent dielectric layer.

5. The optical element according to claim 2, characterized in that, The number of light guide units in each light guide sheet is at least 3.

6. The optical element according to claim 1, characterized in that, The angle between the light guide sheet and the normal of the photosensitive plane is 30°~60°.

7. The optical element according to claim 1, characterized in that, The angle θ between the light guide sheet and the normal of the photosensitive plane is 35°, 37° or 45°.

8. The optical element according to claim 1, characterized in that, The reflectivity of the light guide sheet is 75-100%.

9. The optical element according to claim 2, characterized in that, The inner surface of the light guide unit is a sloping surface, a vertical surface, an arc surface, a polygonal surface, or a wavy surface, and the outer surface of the light guide unit is a sloping surface, a vertical surface, an arc surface, a polygonal surface, or a wavy surface.

10. The optical element according to claim 2, characterized in that, The longitudinal section of the light guide unit is rectangular or parallelogram-shaped.

11. The optical element according to claim 1, characterized in that, The first dielectric layer is a transparent dielectric layer.

12. The optical element according to claim 1, characterized in that, The light guide sheet has a centrally symmetrical structure.

13. The optical element according to claim 1, characterized in that, The light guide sheet is an annular light guide sheet, and the cross-section of the light guide sheet is circular, rectangular, rhomboid, or a positive even-numbered polygon.

14. The optical element according to claim 1, characterized in that, The angle between the multiple light guide sheets and the normal to the photosensitive plane is the same, and the spacing between any two adjacent light guide sheets is the same.

15. The optical element according to claim 1, characterized in that, The light guide sheet has 3 to 7 layers.

16. The optical element according to claim 1, characterized in that, The spacing between two adjacent light guide sheets is 10μm to 40μm.

17. The optical element according to claim 1, characterized in that, The spacing between two adjacent light guide sheets is 10μm, 20μm, 30μm or 40μm.

18. The optical element according to claim 1, characterized in that, The angular response bandwidth of the photosensitive unit, as well as the peak position and curvature of the light intensity distribution curve after the light is processed by the optical element, are changed by adjusting the angle between the light guide sheet and the normal of the photosensitive plane, the spacing between two adjacent light guide sheets, the reflectivity of the light guide sheet, the thickness of the light guide sheet, and the shape of the light guide sheet.

19. The optical element according to claim 1, characterized in that, The optical element also includes a transparent substrate, and the plurality of light guide sheets are disposed on the transparent substrate.

20. The optical element according to claim 1, characterized in that, The light guide sheet is made of metal.

21. The optical element according to claim 1, characterized in that, The light guide sheet includes a substrate and a metal layer disposed on the outer surface of the substrate.

22. The optical element according to claim 21, characterized in that, The substrate material includes at least one of silicone resin, polyimide, silica glass, or epoxy resin.

23. The optical element according to claim 1, characterized in that, The optical element further includes a light homogenizer, which is disposed below the plurality of light guide sheets, and the vertical projection of the light homogenizer at least covers the photosensitive plane.

24. An optical sensor, characterized in that, Includes the optical element and photosensitive unit as described in any one of claims 1-23, wherein the optical element is disposed above the photosensitive unit, and the vertical projection of the optical element at least covers the photosensitive plane of the photosensitive unit.

25. The optical sensor according to claim 24, characterized in that, The optical element is attached to the upper surface of the photosensitive unit.

26. The optical sensor according to claim 24, characterized in that, A support member is provided below the optical element to form an air gap between the optical element and the photosensitive unit. The vertical projection of the air gap covers at least the photosensitive plane of the photosensitive unit. The support member is provided on the photosensitive unit or on the periphery of the photosensitive unit.

27. The optical sensor according to claim 24, characterized in that, The optical sensor further includes an encapsulation layer that encapsulates the optical element and the photosensitive unit.

28. An electronic device, characterized in that, It includes a screen and an optical sensor as described in any one of claims 24-27, the optical sensor being disposed below the screen.

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