Optical element, optical element manufacturing method, head-up display device and vehicle

Abstract

To prevent sunlight backflow into a head-up display device to improve the display effect and device life.SOLUTION: The invention provides an optical element that comprises a substrate 1, a first microstructure layer 2, a second microstructure layer 3 and a plurality of light shielding layers. The substrate includes a lower surface and an upper surface opposite the lower surface. The first microstructure layer is arranged on the lower surface of the substrate, the first microstructure layer comprises a plurality of first protruding parts 21 which makes contact with the substrate and protrude towards the side away from the substrate, each first protruding part comprises a first light-transmitting face which transmits light. The second microstructure layer is arranged on the upper surface of the substrate, the second microstructure layer comprises a plurality of second protruding parts 31, each second protruding part comprises a second light-transmitting surface which transmits light and is approximately parallel to the first light-transmitting surface. Each light shielding layer partially covers the surface of the first protruding part or second protruding part, and the light shielding layers are used for preventing light radiated on the optical element from penetrating through the optical element. The invention further provides a preparation method of the optical element, a head-up display device applying the optical element and a vehicle.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present application relates to the field of displays, and in particular to an optical element, a method for manufacturing an optical element, a head-up display device to which the optical element is applied, and a vehicle to which the head-up display device is applied. [Background technology]

[0002] Although head-up display (HUD) technology is becoming increasingly popular, sunlight retroreflection still remains a problem. This not only affects the display performance, but also causes deterioration of the HUD's internal components, shortening the HUD's lifespan. Currently, the most commonly used method is to use a light-blocking mask to block sunlight. This conventional technology has problems such as being too large, blocking the driver's line of sight, and affecting the output of image light. Summary of the Invention

[0003] One aspect of the present invention provides an optical element, the optical element including a substrate, a first microstructure layer, a second microstructure layer, and a plurality of light-shielding layers; the substrate has a lower surface and an upper surface opposite the lower surface, the first microstructure layer is provided on the lower surface of the substrate, contacts the substrate, and includes a plurality of first protrusions protruding toward a side away from the substrate, each of the first protrusions including a first light-transmitting surface that transmits light; the second microstructure layer is provided on the upper surface of the substrate, contacts the substrate, and includes a plurality of second protrusions protruding toward a side away from the substrate, each of the second protrusions including a second light-transmitting surface that transmits light and is substantially parallel to the first light-transmitting surface; Each of the light-shielding layers partially covers the surface of the first convex portion or the second convex portion, blocking light irradiated onto the optical element from passing through the optical element, and the surface of the first convex portion covered by the light-shielding layer intersects with the first light-transmitting surface, and the surface of the second convex portion covered by the light-shielding layer intersects with the second light-transmitting surface.

[0004] The optical element provided by the embodiments of the present application includes a first microstructure layer and a second microstructure layer respectively disposed on the lower and upper surfaces of a substrate. The first light-transmitting surface of the first microstructure layer and the second light-transmitting surface of the second microstructure layer are approximately parallel, so that the propagation direction of light exiting from one side of the upper surface is the same as the propagation direction of light entering from one side of the lower surface. By partially covering the surface of the first or second convex portion with each light-shielding layer, it is possible to more effectively prevent a portion of the light irradiating the optical element from passing through the optical element, thereby reducing interference between light entering from one side of the upper surface and light entering from one side of the lower surface. When used in a head-up display device, the optical element can emit image light while effectively blocking ambient light, thereby reducing interference of ambient light with the image light and advantageously increasing the image light efficiency of the head-up display device. This can prevent sunlight from flowing back into the head-up display device and more effectively mitigate deterioration of elements inside the head-up display device, advantageously extending the life of the head-up display device.

[0005] In one embodiment, each of the first convex portions extends along a first direction, each of the first light-transmitting surfaces is parallel to the first direction, and the plurality of first convex portions are formed on the lower surface continuously and without intervals along a second direction. Each of the second convex portions extends along the first direction, each of the second light-transmitting surfaces is parallel to the first direction, and the plurality of second convex portions are formed on the upper surface continuously and without intervals along the second direction. The second direction intersects with the first direction.

[0006] In one embodiment, each of the first protrusions and each of the second protrusions is formed in a triangular prism shape. The first convex portion further includes a first side surface and a second side surface, the first side surface, the second side surface and the first light-transmitting surface being sequentially connected, the first side surface, the second side surface and the first light-transmitting surface all being quadrangular, the first side surface being in direct contact with the substrate, and the light-shielding layer being provided on the second side surface. The second convex portion further includes a third side surface and a fourth side surface, the third side surface, the fourth side surface and the second light-transmitting surface being sequentially connected, the third side surface, the fourth side surface and the second light-transmitting surface being all rectangular, the third side surface being in direct contact with the substrate, and the light-shielding layer being provided on the fourth side surface.

[0007] In one embodiment, the angle between the first light-transmitting surface and the second side surface ranges from 30° to 150°, and the angle between the second light-transmitting surface and the fourth side surface ranges from 30° to 150°.

[0008] In one embodiment, the surface roughness Rq1 of the first light-transmitting surface is less than 0.05 μm, the surface roughness Rq2 of the second side surface is 0.2 μm or more and 30 μm or less, the surface roughness Rq3 of the second light-transmitting surface is less than 0.05 μm, and the surface roughness Rq4 of the fourth side surface is 0.2 μm or more and 30 μm or less.

[0009] In one embodiment, the error in parallelism between the first and second light-transmitting surfaces is less than 0.2°.

[0010] In one embodiment, a hard coat film or an anti-reflection film is provided on the first light-transmitting surface on a side farther from the substrate, and the hard coat film or the anti-reflection film is configured to increase the transmittance of light irradiated onto the first light-transmitting surface. A hard coat film or an anti-reflection film is provided on the second light-transmitting surface on a side farther from the substrate, and the hard coat film or the anti-reflection film is configured to increase the transmittance of light irradiated onto the second light-transmitting surface.

[0011] In one embodiment, the substrate is integrally molded with the plurality of first protrusions, and the substrate is integrally molded with the plurality of second protrusions.

[0012] In one embodiment, the light-shielding layer is any one of an ultraviolet absorber, a light-shielding ink, a photoresist, and a light-shielding tape.

[0013] A second aspect of the present invention provides a method for manufacturing an optical element, comprising the following steps: Step 1: Forming a first microstructure layer and a second microstructure layer on opposing lower and upper surfaces of a substrate, respectively, wherein the first microstructure layer contacts the substrate and includes a plurality of first protrusions protruding away from the substrate, and the second microstructure layer contacts the substrate and includes a plurality of second protrusions protruding away from the substrate. Step 2: Forming a plurality of light-shielding layers, each of which partially covers the surface of the first convex portion or the second convex portion, and blocks light irradiated onto the optical element from passing through the optical element.

[0014] In one embodiment, the step of forming a first microstructure layer and a second microstructure layer on opposing lower and upper surfaces of a substrate, respectively, includes forming the first microstructure layer and the second microstructure layer by any one of laser processing, lithography, and nanoimprinting.

[0015] In one embodiment, the step of forming a plurality of light-shielding layers includes forming the light-shielding layers by any one of coating, plating, spraying, and sputtering.

[0016] A third aspect of the present invention provides a head-up display device. The head-up display device includes an image generating unit, a light guide assembly, and any of the optical elements described above. The image generating unit emits image light, the light guide assembly receives the image light, guides it, and transmits it to the optical element, and the optical element receives the image light emitted from the light guide assembly and emits the image light onto a projection medium to form an image.

[0017] The head-up display device according to the embodiments of the present application can more effectively block ambient light and emit image light by providing an optical element according to any one of the above embodiments, which is advantageous in reducing interference between ambient light and image light, improving the image light efficiency of the head-up display device, and preventing sunlight from flowing back into the head-up display device. Therefore, deterioration of elements inside the head-up display device can be more effectively alleviated, which is advantageous in extending the life of the head-up display device.

[0018] In one embodiment, the head-up display device further comprises a housing having an accommodation chamber, the housing having a light outlet with a transparent cover disposed therein, and the optical element being disposed on the side of the transparent cover closer to the image generating unit.

[0019] In one embodiment, the first convex portion has a triangular prism shape, and further includes a first side surface and a second side surface, the first side surface, the second side surface, and the first light-transmitting surface are sequentially connected, the first side surface, the second side surface, and the first light-transmitting surface are all quadrangular, the first side surface is in direct contact with the substrate, and the light-shielding layer is provided on the second side surface. The angle between the image light incident on the optical element and the first light-transmitting surface ranges from 5° to 150°.

[0020] In one embodiment, the second convex portion has a triangular prism shape, and further includes a third side surface and a fourth side surface, the third side surface, the fourth side surface and the second light-transmitting surface are sequentially connected, the third side surface, the fourth side surface and the second light-transmitting surface are all quadrangular, the third side surface is in direct contact with the substrate, and the light-shielding layer is provided on the fourth side surface. The angle between the ambient light incident on the optical element and the fourth side surface ranges from 5° to 150°.

[0021] A fourth aspect of the invention according to the present application provides a vehicle. The vehicle includes a main body and and a head-up display device according to any one of the above embodiments, which is provided on the main body.

[0022] By providing a head-up display device according to any of the above embodiments, the vehicle according to the present application is advantageous in preventing sunlight from flowing back into the interior of the vehicle, and in more effectively mitigating deterioration of components inside the vehicle, thereby extending the life of the vehicle. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a diagram showing the configuration of an optical element according to an embodiment of the present application. [Figure 2] FIG. 2 is a partial cross-sectional view taken along line II-II in FIG. 1 of the present application. [Figure 3] FIG. 3 is a partial cross-sectional view of an optical element according to another embodiment of the present application. [Figure 4] FIG. 4 is a diagram showing a partial cross section of an optical element according to yet another embodiment of the present application. [Figure 5] FIG. 5 is a diagram illustrating partial optical paths of an optical element according to one embodiment of the present application. [Figure 6] FIG. 6 is a diagram showing partial optical paths of an optical element of a comparative example. [Figure 7] FIG. 7 is a diagram showing the configuration of a hard coat film of an optical element according to an embodiment of the present application. [Figure 8] FIG. 8 is a diagram showing the configuration of an anti-reflection film of an optical element according to an embodiment of the present application. [Figure 9] FIG. 9 is a flowchart illustrating a method for manufacturing an optical element according to an embodiment of the present application. [Figure 10] 10A to 10C are cross-sectional views illustrating steps in the method for manufacturing the optical element of FIG. [Figure 11] FIG. 11 is a schematic diagram of a head-up display device according to an embodiment of the present application. [Figure 12] FIG. 12 is a block diagram of a vehicle according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] In the following, technical aspects of the embodiments of the present invention will be clarified and fully described in connection with the drawings of the embodiments of the present invention, but it is clear that the described embodiments are only some embodiments of the present invention, not all embodiments.

[0025] 1 and 2 , an optical element 100 according to an embodiment of the present application includes a substrate 1, a first microstructure layer 2, a second microstructure layer 3, and multiple light-shielding layers 4. The substrate 1 includes a lower surface 11 and an upper surface 12 opposite the lower surface 11. The first microstructure layer 2 is provided on the lower surface 11 of the substrate 1, and includes multiple first protrusions 21 that are in contact with the substrate 1 and protrude away from the substrate 1, each of the first protrusions 21 including a first light-transmitting surface 211 that can transmit light. The second microstructure layer 3 is provided on the upper surface 12 of the substrate 1, and includes multiple second protrusions 31 that are in contact with the substrate 1 and protrude away from the substrate 1, each of the second protrusions 31 including a second light-transmitting surface 311 that can transmit light, and the second light-transmitting surfaces 311 are approximately parallel to the first light-transmitting surface 211. Each of the light-shielding layers 4 partially covers the surface of the first convex portion 21 or the second convex portion 31, blocking light irradiated onto the optical element 100 from passing through the optical element 100, and the surface of the first convex portion 21 covered by the light-shielding layer 4 intersects with the first light-transmitting surface 211, and the surface of the second convex portion 31 covered by the light-shielding layer 4 intersects with the second light-transmitting surface 311.

[0026] The optical element 100 provided by the embodiments of the present application has a first microstructure layer 2 and a second microstructure layer 3 respectively provided on the lower surface 11 and upper surface 12 of the substrate 1, and the first light-transmitting surface 211 of the first microstructure layer 2 and the second light-transmitting surface 311 of the second microstructure layer 3 are approximately parallel to each other, so that the propagation direction of light exiting from one side of the upper surface 12 is the same as the propagation direction of light entering from one side of the lower surface 11. Each of the light-shielding layers 4 partially covers the surface of the first convex portion or the second convex portion, thereby more effectively blocking part of the light irradiated onto the optical element 100 from passing through the optical element 100 and reducing interference between light entering from one side of the upper surface 12 and light entering from one side of the lower surface 11.

[0027] Specifically, the substrate 1, the first microstructure layer 2, and the second microstructure layer 3 are all formed of a light-transmitting material so that image light L1 incident from the lower surface 11 of the first microstructure layer 2 can pass through the substrate 1 and be transmitted from the upper surface 12 of the substrate 1. In the examples of the present application, "transmitting light" means having high transmittance for light in a specific wavelength range (particularly visible light and infrared light ranges), for example, 70% or more, or even 80% or more for light in that wavelength range. The material of the substrate 1 is an optical polymer transparent film substrate such as polyethylene terephthalate (PET), polycarbonate (PC), polymeric methyl methacrylate (PMMA), colorless polyimide (CPI), special acrylic plastic (e.g., AZP resin), or cycloolefin copolymer (COC). The material of the first microstructure layer 2 and the second microstructure layer 3 may be the same as that of the substrate 1, or may be other materials, such as heat-curable materials, ultraviolet-curable materials, acrylic, silicone-type curable materials, or organic-inorganic hybrid materials (e.g., acrylic and silicone copolymers, i.e., acrylic&SiO-copolymers).

[0028] In this embodiment, the substrate 1 has a substantially rectangular shape, and the first convex portions 21 and the second convex portions 31 each have a triangular prism shape. The first convex portions 21 extend along the first direction X, and the first light-transmitting surface 211 is parallel to the first direction X. The multiple first convex portions 21 are formed continuously and without intervals along the second direction Y on the lower surface 11, i.e., adjacent first convex portions 21 are in contact with each other without any gaps on the lower surface 11. In other embodiments, adjacent first convex portions 21 may have gaps (not shown) on the lower surface 11. That is, the multiple first convex portions 21 are formed discontinuously and at intervals along the second direction Y on the lower surface 11. The specific shape is determined according to the needs of use of the optical element 100, but is not particularly limited by the present application. The second protrusions 31 extend along the first direction X, the second light-transmitting surface 311 is parallel to the first direction X, and the multiple second protrusions 31 are formed continuously and without intervals on the upper surface 12 along a second direction Y that intersects with the first direction X. In this embodiment, the first direction X and the second direction Y are perpendicular to each other. In other embodiments, the angle formed between the first direction X and the second direction Y may be other angles, and this application does not particularly limit this.

[0029] In other embodiments, the shapes of the first convex portions 21 and the second convex portions 31 are not limited to these, and may be any shapes that partially transmit the image light L1 incident from the lower surface 11 and partially reflect or absorb the ambient light L2. In addition to a triangular prism shape, the first convex portions 21 and the second convex portions 31 may each be a rod-like protrusion structure having another cross-sectional shape. For example, the cross section of the first convex portions 21 and the second convex portions 31 along the thickness direction of the optical element 100 may be rectangular, trapezoidal, elliptical, semicircular, or the like. Regular shapes such as triangular, rectangular, trapezoidal, elliptical, and semicircular cross sections of the first convex portions 21 and the second convex portions 31 are advantageous for processing compared to other irregular cross-sectional shapes.

[0030] In this embodiment, the substrate 1 is integrally molded with a plurality of first protrusions 21, and the substrate 1 is integrally molded with a plurality of second protrusions 31. That is, there is no boundary between the substrate 1 and the first protrusions 21 and second protrusions 31 on both sides. Specifically, the substrate 1 and the first protrusions 21 and second protrusions 31 may be integrally molded by methods such as hot stamping, injection molding, and UV offset pressing. Integral molding can increase the strength of the protrusions and simplify the process, while the absence of a significant interface between them does not affect the optical path, thereby improving the durability of the microstructure layer.

[0031] Referring to FIG. 3 , in another embodiment, the substrate 1 and the first and second protrusions 21 and 31 on both sides may not be integrally formed. A boundary 13 is formed between the substrate 1 and the first and second protrusions 21 and 31 on both sides. Specifically, the first and second protrusions 21 and 31 are formed by one of laser processing, photolithography, and nanoimprinting. The first and second microstructure layers 2 and 3 are formed by laser processing, and include, for example, a material layer that forms the first and second microstructure layers 2 and 3 on the substrate 1. The material layer is then processed with a laser to remove some of the material layer and preserve some of the material layer, thereby obtaining the first and second microstructure layers 2 and 3. Forming the first and second microstructure layers 2 and 3 by laser processing is a simple process.

[0032] Referring again to Figure 1, the first convex portion 21 further includes a first side surface 212 and a second side surface 213, and the first side surface 212, the second side surface 213, and the first translucent surface 211 are connected in sequence, and the first side surface 212, the second side surface 213, and the first translucent surface 211 are all rectangular, the first side surface 212 is in direct contact with the substrate 1, and a light-shielding layer 4 is provided on the second side surface 213. Since the light-shielding layer 4 is provided on the second side surface 213, the surface roughness Rq1 of the second side surface 213 during processing of the first convex portion 21 is in the range of 0.2 μm to 30 μm (e.g., 0.2 μm to 2 μm, 2 μm to 10 μm, 10 μm to 15 μm, 15 to 30 μm). Setting the surface roughness Rq1 of the second side surface 213 within this range facilitates processing of the light-shielding layer 4 on the second side surface 213, and the resulting optical element 100 has a relatively uniform thickness. The surface roughness Rq2 of the first light-transmitting surface 211 is less than 0.05 μm. When the surface roughness Rq2 of the first light-transmitting surface 211 is within the above range, the surface quality of the optical element 100 can be effectively improved, and the resulting optical element 100 has a relatively uniform thickness. In addition, if the surface roughness Rq20 of the side surface 121 of the substrate 1 is less than 50 μm, the optical element 100 satisfies processing requirements. If the angle formed between the first light-transmitting surface 211 and the second side surface 213 is defined as a first angle α, the range of the first angle α is 30° to 150° (for example, 30° to 50°, 50° to 70°, 70° to 90°, 90° to 120°, 120° to 150°). By keeping the first angle α within this range, it is ensured that light rays incident from one side of the lower surface 11 are emitted from one side of the upper surface 12 as much as possible, and light rays incident from the second side surface 213 on one side of the lower surface 11 can be effectively blocked. Of course, when the first protrusion 21 is integrally molded with the substrate 1, the first side surface 212 and the upper surface 12 of the substrate 1 do not actually exist.

[0033] The second convex portion 31 further includes a third side surface 312 and a fourth side surface 313, the third side surface 312, the fourth side surface 313, and the second light-transmitting surface 311 are connected in sequence, the third side surface 312, the fourth side surface 313, and the second light-transmitting surface 311 are all quadrangular, the third side surface 312 and the substrate 1 are in direct contact, and a light-shielding layer 4 is provided on the fourth side surface 313. Because the light-shielding layer 4 is provided on the fourth side surface 313, the surface roughness Rq3 of the fourth side surface 313 during processing of the second convex portion 31 is in a range of 0.2 μm to 30 μm (e.g., 0.2 μm to 2 μm, 2 μm to 10 μm, 10 μm to 15 μm, 15 to 30 μm). Setting the surface roughness of the fourth side surface 313 within this range makes it easy to process the light-shielding layer 4 on the third side surface 313, and the thickness of the obtained optical element 100 is relatively uniform. The surface roughness Rq4 of the second light-transmitting surface 311 is less than 0.05 μm. When the surface roughness of the second light-transmitting surface 311 is within this range, the surface quality of the optical element 100 can be effectively improved, and the thickness of the resulting optical element 100 can be relatively uniform. If the angle formed between the second light-transmitting surface 311 and the fourth side surface 313 is defined as the second angle β, the second angle β ranges from 30° to 150° (e.g., 30° to 50°, 50° to 70°, 70° to 90°, 90° to 120°, 120° to 150°). When the second angle β is within this range, it is ensured that light rays incident from one side of the bottom surface 11 are emitted from one side of the top surface 12 as much as possible, and light rays incident from the top surface 12 can be effectively blocked. Of course, when the second convex portion 31 is integrally molded with the substrate 1, the third side surface 312 and the top surface 12 of the substrate 1 do not actually exist. 1, the first side surface 212 and the third side surface 312 are imaginary planes (shown by dashed lines) and are not actual interfaces. Each of the light-shielding layers 4 is rectangular and completely covers the second side surface 213 of the first protrusion 21 and the fourth side surface 313 of the second protrusion 31, with the second side surface 213 being approximately parallel to the fourth side surface 313. In another embodiment, the light-shielding layer 4 may partially cover the second side surface 213 of the first protrusion 21 and the fourth side surface 313 of the second protrusion 31, and the second side surface 213 and the fourth side surface 313 may not be parallel, and this application does not particularly limit this.

[0034] The positional relationship between the first side surface 212, the second side surface 213 on which the light-shielding layer 4 is provided, and the first light-transmitting surface 211 is determined according to specific usage needs. The positional relationship between the third side surface 312, the fourth side surface 313 on which the light-shielding layer 4 is provided, and the second light-transmitting surface 311 is also determined according to specific usage needs. For example, the positions of the fourth side surface 313 on which the light-shielding layer 4 is provided and the second side surface 213 may be adjusted to better block light incident from the upper surface 12. Referring to FIG. 4 , in yet another embodiment, the first light-transmitting surface 211 is located on a side of each first protrusion 21 closer to the first direction X, and the second side surface 213 on which the light-shielding layer 4 is provided is located on a side of each first protrusion 21 farther from the first direction X. The second light-transmitting surface 311 is located on a side of each second protrusion 31 farther from the first direction X, and the fourth side surface 313 on which the light-shielding layer 4 is provided is located on a side of each second protrusion 31 closer to the first direction X.

[0035] 5 , in this embodiment, the first light-transmitting surface 211 and the second light-transmitting surface 311 are parallel to each other to achieve good light transmittance. In other embodiments, the first light-transmitting surface 211 and the second light-transmitting surface 311 do not need to be strictly parallel (i.e., they may be approximately parallel) due to errors that may occur during the processing. The error in the parallelism between the first light-transmitting surface 211 and the second light-transmitting surface 311 is less than 0.2°, and the parallelism refers to the degree to which the first light-transmitting surface 211 and the second light-transmitting surface 311 are parallel. For example, if the second light-transmitting surface 311 is shifted from position S1′ to position S2′ or S3′, the angle of incidence of the image light L1 with respect to the boundary surface between the second convex portion 31 and the external environment changes, which affects the reflection ratio of the image light L1 at the boundary surface and the optical efficiency of the optical element 100.

[0036] Referring to FIG. 6, FIG. 6 is a diagram showing the configuration of an optical element 100a of the comparative example. The common differences between the optical element 100a of the comparative example and all the examples of the present application are as follows: No first convex portion is provided on the lower surface 11a of the substrate 1a, and the lower surface 11a of the substrate 1a is the first light-transmitting surface of the optical element 100a. In this comparative example, no first light-transmitting surface parallel to the second light-transmitting surface 311a on the upper surface 12a is provided on the lower surface 11a of the substrate 1a. That is, because the lower surface 11a and the second light-transmitting surface 311a of the upper surface 12a are non-parallel and form a large included angle, most of the light rays incident from the lower surface 11a are reflected back from the second light-transmitting surface 311a to the lower surface 11a, and only a small amount of light is emitted from the second light-transmitting surface 311a, which affects the reflection ratio of the light rays incident from the lower surface 11a and reduces the optical efficiency. In contrast, in the examples of the present application, when the parallelism error between the first light-transmitting surface 211 and the second light-transmitting surface 311 is smaller than 0.2°, the transmittance of the image light L1 is large, which does not affect the reflection ratio of the optical element 100 and does not affect the optical efficiency of the optical element 100.

[0037] 7 and 8 , in other embodiments, in order to achieve high transmittance, the first light-transmitting surface 211 and the second light-transmitting surface 311 are parallel to each other, and a hard coat film 1b or an anti-reflection film 1c is provided on the side of the first light-transmitting surface 211 farther from the substrate 1, where the hard coat film 1b or the anti-reflection film 1c is intended to increase the transmittance of light irradiated onto the first light-transmitting surface 211. The hard coat film 1b or the anti-reflection film 1c is provided on the side of the second light-transmitting surface 311 farther from the substrate 1, where the hard coat film 1b or the anti-reflection film 1c is intended to increase the transmittance of light irradiated onto the second light-transmitting surface 311. For example, if an anti-reflection coating 1c is provided on the side of first light-transmitting surface 211 farther from substrate 1, and an anti-reflection coating 1c is also provided on the side of second light-transmitting surface 311 farther from substrate 1, then when the light wavelength is 420 nm to 760 nm, the anti-reflection coating 1c can be selected to have an absolute reflectance Rabs of less than 2% and an average reflectance Ravg of less than 1%, which is advantageous for reducing the scattering phenomenon of light rays incident on first light-transmitting surface 211 and second light-transmitting surface 311.

[0038] Referring again to FIG. 2, the light-shielding layer 4 is any one of an ultraviolet absorber, a light-shielding ink, a photoresist, and a light-shielding tape. If the light-shielding layer 4 is an ultraviolet absorber, at least a portion of the ambient light L2 incident on the light-shielding layer 4 is absorbed and attenuated. If the light-shielding layer 4 is an light-shielding ink, the light-shielding ink reflects the light back to its original path or directly absorbs it when irradiated with light. The light-shielding ink is an ink made of ultrafine glass powder, and if the light-shielding layer 4 is a photoresist, the light is absorbed when irradiated with light. The photoresist is a mixture of three components: a resin, a sensitizer, and a solvent, and typically has strong light absorption properties at wavelengths below the ultraviolet wavelength band (less than 400 nm). The material of the light-shielding layer 4 is not limited to the above-mentioned materials, but may be a material capable of absorbing ambient light L2 in a specific wavelength range, or a material with an optical density (OD) in the range of 3-5, or the material of the light-shielding layer 4 may be a material capable of reflecting ambient light L2 in a specific wavelength range.

[0039] The optical element 100 provided by the embodiments of the present application has a first microstructure layer 2 and a second microstructure layer 3 respectively provided on the lower surface 11 and upper surface 12 of the substrate 1, and the first light-transmitting surface 211 of the first microstructure layer 2 and the second light-transmitting surface 311 of the second microstructure layer 3 are approximately parallel to each other, so that the propagation direction of light emitted from the upper surface 12 is the same as the propagation direction of light incident from one side of the lower surface 11. Each of the light-shielding layers 4 partially covers the surface of the first convex portion or the second convex portion, thereby more effectively blocking a portion of the light irradiated onto the optical element 100 from passing through the optical element 100 and reducing interference between light incident from the upper surface 12 and light incident from the lower surface 11.

[0040] Referring to FIG. 9, the method for manufacturing the optical element 100 according to the embodiment of the present application includes the following steps S100 and S200.

[0041] Step S100: Form a first microstructure layer and a second microstructure layer on opposite lower and upper surfaces of a substrate, respectively.

[0042] Step S200: Form a plurality of light-shielding layers, each of which partially covers the surface of the first convex portion or the second convex portion.

[0043] 1, the first microstructure layer 2 contacts the substrate 1 and includes a plurality of first protrusions 21 protruding away from the substrate 1, and the second microstructure layer 3 contacts the substrate 1 and includes a plurality of second protrusions 31 protruding away from the substrate 1. Step 100 of forming the first microstructure layer 2 and the second microstructure layer 3 on the opposing lower surface 11 and upper surface 12 of the substrate 1, respectively, further includes step 101 of forming the first microstructure layer 2 and the second microstructure layer 3 by any one of laser processing, lithography, and nanoimprinting.

[0044] 10 , the first microstructure layer 2 and the second microstructure layer 3 are formed by laser processing, for example, by forming a material layer on the substrate 1 to form the first microstructure layer 2 and the second microstructure layer 3. The material layer is then processed with a laser to remove some of the material layer and retain some of the material layer, thereby obtaining the first microstructure layer 2 or the second microstructure layer 3. The substrate 1, the first microstructure layer 2, and the second microstructure layer 3 are then bonded together with an adhesive. In another embodiment, the material layers for the first microstructure layer 2 and the second microstructure layer 3 may be simultaneously formed on both sides of the substrate 1, and then the material layers may be processed with a laser light to remove some of the material layer and retain some of the material layer, thereby obtaining the first microstructure layer 2 and the second microstructure layer 3. Here, the method of forming the first microstructure layer 2 and the second microstructure layer 3 by laser processing involves simple steps.

[0045] The step of forming the first microstructure layer 2 and the second microstructure layer 3 using photolithography (photolithography technology) includes, for example, patterning a photoresist layer on a material layer forming the first microstructure layer 2 or the second microstructure layer 3. The patterned photoresist layer is used to pattern the material layer to form a relief structure, thereby obtaining the first microstructure layer 2 or the second microstructure layer 3. This method is costly because it involves a photolithography device or the like. The process of forming the first microstructure layer 2 and the second microstructure layer 3 by nanoimprinting can, for example, involve applying a material layer for forming the microstructure layer to the substrate 1, placing a mold with a relief structure on the material layer, curing the material layer by ultraviolet light irradiation or heating, and then transferring the molded material to form the substrate 1, the first microstructure layer 2, and the second microstructure layer 3. Forming the first microstructure layer 2 and the second microstructure layer 3 by nanoimprinting technology has the advantage of lower production costs and complexity compared to photolithography technology. Furthermore, the first microstructure layer 2 and the second microstructure layer 3 are formed directly on the substrate 1 without being bonded to the substrate 1 via an adhesive. Adhesives have poor heat resistance and heat dissipation properties, but the optical element 100 of the present application example has excellent heat dissipation and heat resistance. Furthermore, the first microstructure layer 2 and the second microstructure layer 3 are formed directly on the substrate 1, which makes it possible to reduce the thickness of the optical element 100 and reduce costs compared to a bonding method, and also reduces the effect of the adhesive layer on the refraction of the optical path.

[0046] Specifically, the light-shielding layer 4 is used to block light. Step 200 of forming the plurality of light-shielding layers 4 further includes step 201 of forming the light-shielding layer 4 by coating, plating, atomization, spraying, or sputtering. For example, if the light-shielding layer 4 is formed by atomization, the material of the light-shielding layer may be atomized light-shielding ink or light-shielding tape. The total integrated scattering (TIS) of the light-shielding layer 4 must be less than 0.5, which prevents scattering of light irradiated onto the light-shielding layer. The light-shielding layer 4 may be made of a UV absorber, a light-shielding ink, a photoresist, or a light-shielding tape. Here, if the light-shielding layer 4 is made of a UV absorber, at least a portion of the ambient light L2 incident on the light-shielding layer 4 is absorbed and attenuated. Alternatively, the light-shielding layer 4 may be made of a light-shielding ink made of ultrafine glass powder. Due to the principles of lens refraction and concave spherical reflection, the light-shielding ink reflects light irradiated onto the ink back to its original path. The light-shielding layer 4 is a photoresist, which is a mixture of three main components: resin, sensitizer, and solvent, and typically has a strong light-absorbing ability at wavelengths below the ultraviolet wavelength band (less than 400 nm). Note that the material of the light-shielding layer 4 is not limited to the above-mentioned materials, and may be a material that can absorb ambient light L2 in a specific wavelength range, or another material with an optical density (OD) in the range of 3-5, or may be a material that can reflect ambient light L2 in a specific wavelength range.

[0047] 11 , a head-up display device 500 according to an embodiment of the present application includes the optical element 100 according to any of the above-described embodiments, an image generating unit 51, and a light guide assembly 52. ​​The image generating unit 51 emits image light L1. The light guide assembly 52 receives the image light L1, guides it, and transmits it to the optical element 100. The optical element 100 receives the image light L1 emitted by the light guide unit 52, and emits the image light L1 onto a projection medium 55 to form an image.

[0048] By providing the optical element 100 according to any one of the above embodiments, the head-up display device 500 according to the present application can more effectively block the ambient light L2 and emit the image light L1, which is advantageous for reducing interference between the ambient light L2 and the image light L1, for increasing the optical efficiency of the image light L1 of the head-up display device 500, and for preventing sunlight from flowing back into the head-up display device 500. Therefore, deterioration of the elements inside the head-up display device 500 can be more effectively alleviated, which is advantageous for extending the life of the head-up display device 500.

[0049] The head-up display device 500 further includes a housing 53 having an accommodation chamber 53a. The housing 53 has a light outlet 53a through which a transparent cover 54 is disposed. The optical element 100 is disposed on the side of the transparent cover 54 that is closer to the image generating unit 51. Specifically, the optical element 100 is attached to both sides of the housing 53, the transparent cover 54 is attached to the housing 53, and the position of the reflecting mirror 521 in the light guide assembly 52 is adjusted. This allows the incident angle of the image light L1 on the optical element 100 to be adjusted so that the image projected on the projection medium 55 is clear and complete. The projection medium 55 receives the partial image light L1 emitted from the optical element 100 and forms a virtual image on the side farther from the user. In this embodiment, the projection medium 55 is a windshield. Specifically, the structure of the projection medium 55 can be two-layered glass, or a single-layered glass. Between the two layers of glass, a thin film sandwich can be added according to the user's needs to eliminate double images, and the glass can be thicker on the top and thinner on the bottom to make the image clearer. In another embodiment, the projection medium 55 can be a semi-reflective and semi-transmissive receiving screen, and this application does not particularly limit this.

[0050] In this embodiment, the head-up display device 500 is a windshield-type head-up display device. In other embodiments, the head-up display device 500 may be a combination head-up display device, an augmented reality head-up display device, or a holographic projection head-up display device. For example, if the head-up display device 500 is a combination head-up display device, the projection medium 55 may be a semi-reflective / semi-transmissive receiving screen. If the head-up display device 500 is a holographic projection head-up display device, the light guide assembly 52 is a hologram lens, and the projection medium 55 is a flat-plate optical waveguide. The ultra-thin structure and two-dimensional pupil dilation function of the flat-plate optical waveguide can reduce the volume of the head-up display device. Furthermore, if the head-up display device 500 is a holographic projection head-up display device, the image generation unit 51 may include a light source, a spatial light modulation component, a projection lens, and a computer-generated holography (CGH) processor for generating a holographic image. The position of the hologram image is calculated in real time using the CGH, and the spatial light modulation component is used to phase-modulate the light source light emitted from the received light source. The modulated light beam is focused on the focal plane of the projection lens to form the hologram to be projected, and the hologram to be projected is projected onto the projection medium 55 by the projection lens through the optical element 100. The image generation unit 51 may further include a light source (not shown) for generating image light L1, such as a light emitting diode, an organic light emitting diode, or a micro light emitting diode, and the present application does not particularly limit this.

[0051] 4 and 11 , in the optical element 100, the plurality of first convex portions 21 are formed continuously and without intervals along the second direction Y on the lower surface 11, and the plurality of second convex portions 31 are formed continuously and without intervals along the second direction Y on the upper surface 12, with the first direction X and the second direction Y intersecting and being in the same plane. The first convex portion 21 of the optical element 100 has a triangular prism shape, and the first convex portion 21 further includes a first side surface 212 and a second side surface 213, the first side surface 212, the second side surface 213, and the first light-transmitting surface 211 are connected in sequence, and the first side surface 212, the second side surface 213, and the first light-transmitting surface 211 are all quadrangular, the first side surface 212 is in direct contact with the substrate 1, and a light-shielding layer 4 is provided on the second side surface 213. The second protrusion 31 has a triangular prism shape and further includes a third side surface 312 and a fourth side surface 313. The third side surface 312, the fourth side surface 313, and the second light-transmitting surface 311 are sequentially connected. The third side surface 312, the fourth side surface 313, and the second light-transmitting surface 311 are all quadrangular. The third side surface 312 and the substrate 1 are in direct contact with each other. A light-shielding layer 4 is provided on the fourth side surface 313. Note that in FIG. 1 , the first side surface 212 and the third side surface 312 are imaginary planes (indicated by dashed lines) and are not actual interfaces. Each of the light-shielding layers 4 has a rectangular shape and completely covers the second side surface 213 of the first protrusion 21 and the fourth side surface 313 of the second protrusion 31. The second side surface 213 is approximately parallel to the fourth side surface 313. In another embodiment, the light-shielding layer 4 may partially cover the second side surface 213 of the first convex portion 21 and the fourth side surface 313 of the second convex portion 31, and the second side surface 213 and the fourth side surface 313 may not be parallel, and this application does not particularly limit this.

[0052] If the angle between the image light L1 incident on the optical element 100 and the first light-transmitting surface 211 is defined as a third angle γ, the third angle γ is in the range of 5° to 150° (for example, 5° to 30°, 30° to 50°, 50° to 70°, 70° to 90°, 90° to 120°, 120° to 150°), and most of the image light L1 incident on the optical element 100 can be transmitted through the first light-transmitting surface 211. If the angle between the ambient light L2 incident on the optical element 100 and the fourth side surface 313 is defined as the fourth angle θ, the fourth angle θ is in the range of 5° to 150° (for example, 5° to 30°, 30° to 50°, 50° to 70°, 70° to 90°, 120°, 120° to 150°), and when the amount of incident ambient light L2 is reduced, interference with the amount of output image light L1 can be prevented.

[0053] By providing the optical element 100 according to any one of the above embodiments, the head-up display device 500 according to the present application can more effectively block the ambient light L2 and emit the image light L1, which is advantageous for reducing interference between the ambient light L2 and the image light L1, for increasing the optical efficiency of the image light L1 of the head-up display device 500, and for preventing sunlight from flowing back into the head-up display device 500. Therefore, deterioration of the elements inside the head-up display device 500 can be more effectively alleviated, which is advantageous for extending the life of the head-up display device 500.

[0054] 12 , a vehicle 600 according to the present embodiment includes a main body 601 and a head-up display device 500 according to any one of the above-described embodiments, with the head-up display device 500 mounted on the main body 601. The vehicle 600 may be an electric vehicle, a gasoline-powered vehicle, or a diesel-powered vehicle, and the present application does not place any particular restrictions on the type of vehicle. Specifically, the head-up display device 500 utilizes the principle of optical reflection to project important driving-related information (e.g., driving speed, battery voltage, tank water temperature, engine RPM, fuel economy, navigation route, etc.) onto the upper surface of the projection medium 55, which is then reflected in a balanced manner to the driver's eyes, preventing the driver from looking down at the dashboard and becoming distracted while driving. This assists the driver in driving the vehicle 600, improves safety, and provides a better driving experience.

[0055] The vehicle 600 according to the embodiment of the present application is provided with the head-up display device 500 described in any of the above embodiments, which is advantageous in preventing sunlight from flowing back into the interior of the vehicle 600, and is advantageous in more effectively mitigating deterioration of components inside the vehicle 600, thereby extending the life of the vehicle, and improving the driving efficiency of the vehicle 600.

[0056] The above embodiments are for the purpose of explaining the present invention, but are not intended to limit the present invention. Those skilled in the art should recognize that appropriate modifications and alterations to the above embodiments are within the scope of the essential spirit of the present invention and are within the scope of the claims.

[0057] 100, 100a optical elements 1, 1a board 1b Hard coat film 1c Anti-reflection coating 11, 11a Bottom surface 12, 12a top surface 121 Side 13 Boundary 2 First microstructure layer 21 First convex part 211 1st transparent surface 212 First aspect 213 Second aspect 3 Second microstructure layer 31 Second convex part 311, 311a 2nd transparent surface 312 Third aspect 313 Fourth aspect 4 Light blocking layer 500 Head-up display device 51 Image Generation Unit 52 Light guide assembly 521 Reflector 53 Cabinet Containment Cell 53a 53b Idemitsu Exit 54 Transparent cover 55 Projection medium 600 vehicles 601 Main Unit S100, S101, S200, S201 process α 1st angle β second angle γ 3rd angle θ 4th angle L1 Image Light L2 ambient light X 1st direction Y Second direction

Claims

1. A head-up display device, the head-up display device includes an image generating unit, a light guide assembly, and an optical element; The optical element includes a substrate, a first microstructure layer, a second microstructure layer, and a plurality of light-shielding layers; the substrate has a lower surface and an upper surface opposite to the lower surface, the first microstructure layer is provided on the lower surface of the substrate and includes a plurality of first convex portions, the plurality of first convex portions contacting the substrate and protruding toward a side away from the substrate, and each of the first convex portions includes a first light-transmitting surface that transmits light; the second microstructure layer is provided on the upper surface of the substrate and includes a plurality of second convex portions, the plurality of second convex portions contacting the substrate and protruding toward a side away from the substrate, and each of the second convex portions includes a second light-transmitting surface that transmits light and is approximately parallel to the first light-transmitting surface; each of the light-shielding layers partially covers a surface of the first convex portion or the second convex portion, and blocks light irradiated onto the optical element from passing through the optical element; the surface of the first convex portion covered with the light-shielding layer intersects with the first light-transmitting surface, and the surface of the second convex portion covered with the light-shielding layer intersects with the second light-transmitting surface; the image generating unit emits image light, the light guide assembly receives the image light, guides the image light, and transmits it to the optical element, the optical element receives the image light emitted from the light guide assembly and emits the image light onto a projection medium to form an image; an angle between the image light incident on the optical element and the first light-transmitting surface is in the range of 5° to 150°; A head-up display device.

2. The first protrusion and the second protrusion are each formed in a triangular prism shape, each of the first convex portions extends along a first direction, each of the first light-transmitting surfaces is parallel to the first direction, and the plurality of first convex portions are formed on the lower surface continuously and without intervals along a second direction; each of the second convex portions extends along the first direction, each of the second light-transmitting surfaces is parallel to the first direction, and the plurality of second convex portions are formed on the upper surface continuously and without intervals along the second direction; The head-up display device according to claim 1 , wherein the second direction intersects with the first direction.

3. the first protrusion further includes a first side surface and a second side surface, the first side surface, the second side surface, and the first light-transmitting surface are sequentially connected, the first side surface, the second side surface, and the first light-transmitting surface are all quadrangular, the first side surface is in direct contact with the substrate, and the light-shielding layer is provided on the second side surface; the second convex portion further includes a third side surface and a fourth side surface, the third side surface, the fourth side surface, and the second light-transmitting surface are sequentially connected, the third side surface, the fourth side surface, and the second light-transmitting surface are all quadrangular, the third side surface is in direct contact with the substrate, and the light-shielding layer is provided on the fourth side surface; 3. The head-up display device according to claim 2.

4. A head-up display device as described in Claim 3, characterized in that the angular range between the first translucent surface and the second side surface is 30° to 150°, and the angular range between the second translucent surface and the fourth side surface is 30° to 150°.

5. A head-up display device as described in Claim 3, characterized in that the surface roughness Rq1 of the first translucent surface is less than 0.05 μm, the surface roughness Rq2 of the second side surface is 0.2 μm to 30 μm, the surface roughness Rq3 of the second translucent surface is less than 0.05 μm, and the surface roughness Rq4 of the fourth side surface is 0.2 μm to 30 μm.

6. A head-up display device as described in claim 1, characterized in that the error in parallelism between the first translucent surface and the second translucent surface is less than 0.2°.

7. A hard coat film or an anti-reflection film is provided on the side of the first light-transmitting surface farther from the substrate, and the hard coat film or the anti-reflection film is intended to increase the transmittance of light irradiated onto the first light-transmitting surface; 2. The head-up display device according to claim 1, wherein a hard coat film or an anti-reflection film is provided on the side of the second light-transmitting surface farther from the substrate, and the hard coat film or the anti-reflection film is intended to increase the transmittance of light rays irradiated onto the second light-transmitting surface.

8. A head-up display device as described in claim 1, characterized in that the substrate is molded integrally with the plurality of first convex portions, and the substrate is molded integrally with the plurality of second convex portions.

9. A head-up display device as described in claim 1, characterized in that the light-shielding layer is any one of an ultraviolet absorber, a light-shielding ink, a photoresist, and a light-shielding tape.

10. The head-up display device according to claim 1, further comprising a housing having an accommodation chamber, the housing having a light outlet through which a transparent cover is disposed, and the optical element being disposed on a side of the transparent cover closer to the image generating unit.

11. A vehicle, The main body and A vehicle comprising: the head-up display device according to claim 1 provided on the main body.

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