Optical film and head-up display device

Abstract

The invention discloses an optical film and a head-up display device, the optical film comprises a substrate and a plurality of first microstructures located in the substrate, the light transmittance of the substrate is smaller than that of the first microstructures, and the substrate comprises a first surface and a second surface which are oppositely arranged; the first microstructures extend in the first direction and are periodically arranged in the second direction, orthographic projections of the first microstructures on the first section are first isosceles triangles, the bottoms of the first isosceles triangles are located on the first surface, an incident light transmission channel or an emergent light transmission channel is formed between every two adjacent first microstructures, and the first direction intersects with the second direction. The first section is perpendicular to the first direction; the optical film is attached to a projection substrate of the head-up display device, high reflection of light rays which are emitted by a display module and want to convey information can be achieved, low reflection of ambient light at other angles can be achieved, and therefore the display contrast ratio is improved, and the visual effect is improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of display technology, and in particular to an optical film and a head-up display device. Background Art

[0002] At present, the existing vehicle-mounted projection head-up display (HUD) reflects the display information through a projection substrate (such as a windshield or a separately set reflective substrate) and then enters the human eye. This method requires the projection substrate to have a high reflective ability to light, so that the light irradiated from the display screen to the projection substrate can be reflected as much as possible to the human eye, but the highly reflective projection substrate also leads to high reflection of ambient light, which causes the ambient light to interfere with the visual effect of the HUD information light to be conveyed, resulting in a decrease in display contrast and affecting the HUD display effect. Summary of the invention

[0003] Based on this, the present invention provides an optical film and a head-up display device. When the optical film is attached to the projection substrate of the head-up display device, it can achieve high reflection of light rays of a specific angle emitted by the display module that are intended to convey information, while having low reflection of ambient light at other angles, thereby increasing display contrast and improving visual effects.

[0004] In a first aspect, the present invention provides an optical film, comprising:

[0005] A substrate, the substrate comprising a first surface and a second surface arranged opposite to each other;

[0006] A plurality of first microstructures are located in a substrate, wherein the first microstructures extend along a first direction and are periodically arranged along a second direction, wherein the positive projection of the first microstructure on the first section is a first isosceles triangle, wherein the base of the first isosceles triangle is located on the first surface, and an incident light transmission channel or an outgoing light transmission channel is formed between two adjacent first microstructures, wherein the first direction intersects the second direction, and the first section is perpendicular to the first direction; wherein the light transmittance of the substrate is less than the light transmittance of the first microstructure.

[0007] In a second aspect, the present invention provides a head-up display device, including an image generating unit, a projection substrate, and the optical film provided in the first aspect, wherein the optical film is arranged on a side of the projection substrate close to the image generating unit.

[0008] The optical film suitable for a head-up display device provided by the present invention includes a substrate and a plurality of first microstructures located in the substrate, the light transmittance of the substrate is less than the light transmittance of the first microstructures, the substrate includes a first surface and a second surface arranged opposite to each other; the first microstructures extend along a first direction and are periodically arranged along a second direction, the orthographic projection of the first microstructure on the first section is a first isosceles triangle, the base of the first isosceles triangle is located on the first surface, and an incident light transmission channel or an outgoing light transmission channel is formed between two adjacent first microstructures. The proposal attaches an optical film with a special structure and high reflectivity for certain specific angles of light to the projection substrate of the head-up display device, so that only the light of a specific angle emitted by the display module that is intended to convey information is highly reflected, while the ambient light at other angles is less reflected, thereby improving the display contrast and the visual effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of an optical film provided by the present application applied to a head-up display device;

[0010] Figure 2 is a schematic top view of an optical film provided by the present application;

[0011] Figure 3 yes Figure 1 A schematic cross-sectional view of an optical film along the AA' direction;

[0012] Figure 4 is a top view schematic diagram of another optical film provided by the present application;

[0013] Figure 5 yes Figure 4 A schematic cross-sectional view of an optical film along the BB' direction;

[0014] Figure 6 yes Figure 1 A schematic cross-sectional view of another optical film along the AA' direction;

[0015] Figure 7 yes Figure 4 A schematic cross-sectional view of another optical film along the BB' direction;

[0016] Figure 8 is a top view schematic diagram of another optical film provided by the present application;

[0017] Fig. 9 is a top view schematic diagram of another optical film provided by the present application;

[0018] Fig.10 is a top view schematic diagram of another optical film provided by the present application;

[0019] Fig.11is a top view schematic diagram of another optical film provided by the present application;

[0020] Fig.12 is a structural schematic diagram of another head-up display device provided by the present application;

[0021] Fig.13 It is a structural schematic diagram of a head-up display device provided by the present application applied in a car. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0023] Based on one or more of the above technical problems, an embodiment of the present invention provides an optical film suitable for head-up display. Figure 1 is a schematic diagram of an optical film provided by the present application applied to a head-up display device, Figure 2 is a schematic top view of an optical film provided by the present application, Figure 3 yes Figure 1 A schematic diagram of a cross section of an optical film along the AA' direction, see Figure 1-Figure 3 , an optical film 20 provided in the present application includes a substrate 21 and a plurality of first microstructures 22 located in the substrate 21. The light transmittance of the substrate 21 is less than the light transmittance of the first microstructures 22. In a specific implementation, the substrate 21 can be made of a transparent material, and the first microstructures 22 can be made of an opaque material. The substrate 21 includes a first surface M1 and a second surface M2 that are oppositely arranged. The first microstructures 22 extend along a first direction X and are periodically arranged along a second direction Y. The orthographic projection of the first microstructure 22 on the first section is a first isosceles triangle. The base of the first isosceles triangle is located on the first surface M1. An incident light transmission channel or an outgoing light transmission channel is formed between two adjacent first microstructures 22. Among them, the first direction X intersects with the second direction Y, and the first section (refers to Figure 3 The first cross section refers to the cross section of the first microstructure 22 on the ZY plane in the middle) which is perpendicular to the first direction X. Figure 3 Section on the ZY plane.

[0024] refer to Figure 1, the optical film 20 provided in the embodiment of the present application can be attached to the side of the projection substrate 30 in the head-up display device HUD facing the image generation unit (PGU) 10. Among them, the head-up display device HUD can be a windshield-type head-up display (Windshield-type Head-up Display, W-HUD), an augmented reality head-up display (Augmented Reality Head-up Display, AR-HUD), etc. The image generation unit 10 is configured to output the image light of the head-up display, such as a liquid crystal display panel, an organic or inorganic light-emitting display panel or a projector, etc., for providing a virtual image. In vehicle-mounted applications, the displayed content may include dashboard information, navigation information, lane indicators, construction indicators, accident indicators, and pedestrian detection indicator information.

[0025] Specifically, refer to Figure 2-Figure 4 , the substrate 21 can be made of a material with high light transmittance, such as epoxy resin or acrylic resin material. A plurality of first microstructures 22 with low light transmittance are arranged in the substrate 21, which have the function of blocking or absorbing light. The material of the first microstructure 22 can be a black material, such as a carbon black or pigment material. In other words, the image light output by the image generation unit 10 for the head-up display can pass through the substrate 21, but cannot pass through the first microstructure 22. The structure and arrangement of the first microstructure 22 are as follows:

[0026] The first microstructure 22 is along Figure 2 Extending in the X direction, along Figure 2 The first microstructure 22 is arranged periodically in the Y direction. Figure 3 The positive projection of the ZY section is a first isosceles triangle, the base of the first isosceles triangle is located on the first surface M1, and an incident light transmission channel or an outgoing light transmission channel is formed between two adjacent first microstructures 22, so as to form a periodically arranged light absorption structure. For example, when the light S' reaches the first microstructure 22, the light S' is blocked or absorbed.

[0027] The incident light transmission channel and the outgoing light transmission channel refer to the area of ​​the substrate 21 between two adjacent first microstructures 22, which can transmit light. For different light, the area of ​​the substrate 21 between two adjacent first microstructures 22 can be called the incident light transmission channel or the outgoing light transmission channel. For example, Figure 3 The region a is both an incident light transmission channel for the first light ray a1 and an outgoing light transmission channel for the second light ray a2.

[0028] Combination Figure 1 and Figure 3In the head-up display device HUD application, the first part of the light S1 is the image light output by the image generation unit 10, and the second part of the light S2 is the ambient light. The first part of the light S1 enters the substrate 21 after being incident on the first surface M1, is incident into the substrate 21 through the incident light transmission channel, is reflected by the second surface M2 and output to the outside of the optical film 20 through the outgoing light transmission channel, and then reaches the user's observation range to form a virtual image. The second part of the light S2 enters the substrate 21 after being incident on the first surface M1, and at least part of the second part of the light S2 is blocked and absorbed by the first microstructure 22 and cannot be emitted. It can be seen that the optical film 20 provided in the embodiment of the present application can transmit the first part of the light S1 at a specific angle, block and absorb at least part of the second part of the light S2. When it is used in the display device HUD, it can reduce the brightness of the ambient light, improve the display contrast, and optimize the virtual image imaging visual effect.

[0029] In summary, the optical film provided in the embodiments of the present application can highly reflect light at a specific angle and have a low reflection for unnecessary light. In the application of a head-up display device, it can be attached to the surface of a projection substrate, and can achieve high reflection of only light at a specific angle emitted by the display module that is intended to convey information, while having a low reflection for ambient light at other angles, thereby increasing display contrast and improving visual effects.

[0030] Based on the above embodiments, continue to refer to Figure 3 , the incident angle △1 of the first part of the light S1 is greater than or equal to the first incident angle θ1, and less than or equal to the second incident angle θ2, that is, θ1≤△1≤θ2. The incident angle △2 of the second part of the light S2 is less than the first incident angle θ1, or greater than the second incident angle θ2, that is, △2<θ1 or △2>θ2. The incident angle is the angle between the light incident on the first surface M1 and the normal perpendicular to the first surface M1.

[0031] It can also be understood that the first incident angle θ1 is the minimum incident angle of the first part of the light S1 that the user needs to observe, and the second incident angle θ2 is the maximum incident angle of the first part of the light S1 that the user needs to observe. In the embodiment of the present application, the structure of the first microstructure 22 can be adjusted so that the first part of the light S1 with an incident angle △1 can pass through the incident light transmission channel to reach the second surface M2, and after being reflected by the second surface M2, pass through the exit light transmission channel to exit from the first surface M1, while blocking and absorbing the second part of the light S2 with an incident angle △2, so that it cannot exit from the first surface M1.

[0032] Optionally, θ1=10°, θ2=30°, the incident angle △1 of the first portion of light S1 is greater than or equal to 10° and less than or equal to 30°, that is, the value range of △1 is 10°~30°, and the incident angle of the second portion of light S2 is less than 10°, or greater than 30°, that is, the value range of △2 is less than 10° or greater than 30°.

[0033] It should be noted that the angles of θ1 and θ2 may also be reasonably adjusted according to actual application requirements, and the embodiments of the present application do not impose any specific limitations thereto.

[0034] Figure 4 is a top view schematic diagram of another optical film provided by the present application, Figure 5 yes Figure 4 A schematic cross-sectional view of an optical film along the BB' direction is shown in FIG. Figure 4 and Figure 5 The optical film 20 also includes a plurality of second microstructures 23 located in the substrate 21. The second microstructures 23 extend along the first direction X and are periodically arranged along the second direction Y. The orthographic projections of the first microstructures 22 and the orthographic projections of the second microstructures 23 on the second surface M2 are alternately arranged along the second direction Y. The orthographic projection of the second microstructure 23 on the first section is a second isosceles triangle, the base of the second isosceles triangle is located on the second surface M2, and an incident light transmission channel or an outgoing light transmission channel is formed between two adjacent first microstructures 22 and second microstructures 23. The light transmittance of the substrate 21 is less than the light transmittance of the second microstructure 23.

[0035] In the examples of this application, refer to Figure 4 and Figure 5 The optical film 20 provided in the embodiment of the present application can also be designed to set a first microstructure 22 capable of absorbing light on the first surface M1 of the substrate 21, and set a second microstructure 23 capable of absorbing light on the second surface M2, both of which have isosceles triangle cross-sections, and both along Figure 4 In this way, the incident light transmission channel A and the outgoing light transmission channel B are symmetrical about the first microstructure 22 or the second microstructure 23, so that at least part of the light propagating along the incident light transmission channel A can be reflected by the second surface M2 and then emitted from the optical film 20 along the outgoing light transmission channel B, while the light outside the incident light transmission channel A is absorbed by the first microstructure 22 or the second microstructure 23, thereby playing the role of selecting the light of a specific incident angle to be emitted. For example, referring to Figure 5As shown, the first part of the light S1 is incident on the second surface M2 of the substrate 21 through the incident light transmission channel A formed between two adjacent first microstructures 22 and between the first microstructure 22 and the second microstructure 23, and is reflected by the second surface M2 and then transmitted through the exit light transmission channel B formed between the first microstructure 22 and the second microstructure 23 and between two adjacent first microstructures 22, and then exits from the first surface M1, and the second part of the light S2 is directly absorbed by the first microstructure 22. At this time, the first part of the light S1 is the image light transmitted to the human eye, and the second part of the light S2 is the ambient light that will not be transmitted to the human eye and needs to be blocked.

[0036] It should be noted that the first portion of light S1 and the second portion of light S2 in the drawings of the embodiment of the present application are merely exemplary illustrations, and the paths of the actual light rays may be the same or similar, and the embodiment of the present application does not make any specific limitations.

[0037] refer to Figure 4 and Figure 5 When the first microstructure 22 and the second microstructure 23 are simultaneously provided in the optical film 20 , there are various structural designs for the structural dimensions of the first microstructure 22 and the second microstructure 23 .

[0038] A feasible implementation method is shown in FIG. Figure 4 and Figure 5 , the size of the first isosceles triangle in the second direction Y is d1, the height of the first isosceles triangle is h1, the first incident angle is θ1, the size of the substrate 21 in the third direction is T, the height of the second isosceles triangle is h2, and the size parameters of the first microstructure 22 and the second microstructure 23 satisfy: d1=2T×tanθ1, h1≤T, h2≤T. Among them, the third direction Z is the thickness direction of the substrate 21.

[0039] In the embodiment of the present application, the dimension d1 of the first microstructure 22 along the Y direction in the figure is related to the thickness T of the optical film 20 and the minimum incident angle (first incident angle θ1) of the first part of the light S1 that the user needs to reflect. According to the geometric relationship, it can be reasonably adjusted according to θ1 and T, so that only the first part of the light S1 with a specific incident angle △1 can be reflected to make it pass through the incident light transmission channel A and the outgoing light transmission channel B formed between the first microstructure 22 and the second microstructure 23 and then emerge, and at the same time, the second part of the light S2 with an incident angle △2 can be blocked and absorbed, which has the advantage of flexibility and can meet the application of various incident angles.

[0040] A feasible implementation method, continue to refer to Figure 4 and Figure 5 , the period of the first microstructure 22 is P, wherein the period of the first microstructure 22 refers to the period of the first microstructure 22 along Figure 4The distance between the bottom centers of two adjacent first microstructures 22 in the Y direction. The size of the first isosceles triangle in the second direction Y is d1, the height of the first isosceles triangle is h1, the size of the second isosceles triangle in the second direction Y is d2, the height of the second isosceles triangle is h2, the second incident angle is θ2, and the size of the substrate 21 in the third direction Z is T. The size parameters of the first microstructure 22 and the second microstructure 23 satisfy the relationship: d1<2(PT×tanθ2), h2=P / (2tanθ2), d2≤P. When the above relationship is satisfied, the second microstructure 23 limits the maximum value of the second incident angle θ2, and the light with an incident angle greater than θ2 will be blocked and absorbed by the top of the second microstructure 23.

[0041] A feasible implementation method, continue to refer to Figure 4 and Figure 5 , the dimension d1 of the first microstructure 22 along the Y direction in the figure can also be designed as, d1=2(PT×tanθ2), h2≤P / (2tanθ2). When the above relationship is satisfied, the first microstructure 22 limits the maximum value of the second incident angle θ2, and the light with an incident angle greater than θ2 will be blocked and absorbed by the bottom of the first microstructure 22.

[0042] According to the geometric relationship, the first microstructure 22 can also be limited along the second incident angle θ2, the period P of the first microstructure 22, and the size T of the substrate 21 in the Z direction. Figure 4 The size in the Y direction and the height h2 and d2 of the second microstructure 23 are reasonably adjusted according to the above relationship, so that only the first part of the light S1 with a specific incident angle △1 can be reflected so that it can pass through the incident light transmission channel A and the outgoing light transmission channel B formed between the first microstructure 22 and the second microstructure 23 and then emerge. At the same time, the second part of the light S2 with an incident angle △2 can also be blocked and absorbed. It has the advantage of flexibility and can meet the application of various incident angles.

[0043] A feasible implementation method, continue to refer to Figure 3 , combined with Figure 4 and Figure 5 Only the first microstructure 22 may be provided without providing the second microstructure, and the dimension d1 of the first microstructure 22 along the Y direction in the figure may also be designed as d1=2(PT×tanθ2).

[0044] In summary, in the embodiments of the present application, according to the geometric relationship, when the parameters d1 and h1 of the first microstructure 22, the parameters d2 and h2 of the second microstructure 23, etc. satisfy any of the above relationships, it is possible to achieve the reflection of only the first part of the light S1 at the incident angle △1, and the shielding and absorption of the second part of the light S2 at the incident angle △2. It should be noted that the structural dimensions of the first microstructure 22 and the second microstructure 23 provided in the embodiments of the present application are combined with the first incident angle θ1, the second incident angle θ2, the period P of the first microstructure 22, the thickness T of the optical film 20, etc., and there are multiple structural designs, which have the advantage of flexibility and can meet the application of multiple incident angles.

[0045] Based on the above embodiments, continue to refer to Figure 4 and Figure 5 The first microstructure 22 and the second microstructure 23 are made of the same material, for example, both are made of black material, such as carbon black or pigment material, and have the same light absorption effect. Such a design can also reduce the preparation cost and difficulty of the optical film 20.

[0046] Based on the above embodiments, Figure 4 , the orthographic projection of the first microstructure 22 on the second surface M2 does not overlap with the orthographic projection of the second microstructure 23 on the second surface M2. Such a design needs to take into account both the reflection of the desired light by the optical film 20 and the absorption of the unwanted ambient light, while also ensuring the transmittance of the optical film 20 in its thickness direction. For example, referring to Figure 1 The optical film 20 provided in the embodiment of the present application can be attached to the windshield of a car. The windshield needs to meet a certain transmittance. The present application sets the orthographic projection of the first microstructure 22 on the second surface M2 and the orthographic projection of the second microstructure 23 on the second surface M2 to have no overlap, so as to avoid the first microstructure 22 and the second microstructure 23 blocking the light in front of the vehicle, thereby ensuring a clear field of vision for the driver and thus ensuring safe driving of the car.

[0047] Figure 6 yes Figure 1 A schematic cross-sectional view of another optical film along the AA' direction is shown in FIG. Figure 7 yes Figure 4 A schematic cross-sectional view of another optical film along the BB' direction is shown in FIG. Figure 6 and Figure 7 The optical film 20 further includes a reflection enhancement film 24 disposed on the second surface M2. This arrangement can improve the reflection efficiency of the second surface M2 for the first portion of light S1, which is beneficial to improving the brightness and clarity of the virtual image of the head-up display device HUD in the application of the head-up display device HUD.

[0048] In the above embodiment, the reference Figure 6 and Figure 7 The refractive index of the anti-reflection film 24 is less than that of the substrate 21. By utilizing the principle of total reflection of light, at least a first portion of the incident light S1 can be made to enter the anti-reflection film 24 with a low refractive index from the substrate 21 with a high refractive index and be totally reflected, thereby increasing the reflection efficiency of the second surface M2.

[0049] Figure 8 is a top view schematic diagram of another optical film provided by the present application. Based on the above embodiment, the extension length of the first microstructure 22 can be designed in a variety of ways, specifically:

[0050] A feasible implementation method is shown in FIG. Figure 2 , the first microstructure 22 is along Figure 2 The first direction X may be continuous. A feasible implementation method is as follows: Figure 8 , the first microstructure 22 is along Figure 8 The first direction X may be discontinuous. The first microstructure 22 includes at least two first sub-microstructures 22a, each of which is along Figure 8 The first sub-microstructures 22a are arranged in an array, and are arranged in the X direction and in the Y direction, forming a plurality of first sub-microstructures 22a arranged in an array. In the present application, there is a gap between two adjacent first sub-microstructures 22a, and the reflection efficiency of the first part of the light S1 can be ensured in the first sub-microstructure 22a interval, and the transmittance of the optical film 20 in the thickness direction (Z direction in the figure) can be improved to meet the transmittance requirements of practical applications.

[0051] Fig. 9 is a top view schematic diagram of another optical film provided by the present application, Fig.10 2 is a top view schematic diagram of another optical film provided by the present application. When the optical film 20 is composed of the first microstructure 22 and the second microstructure 23, in order to improve the transmittance of the optical film 20 in its thickness direction (Z direction in the figure), the first microstructure 22 and the second microstructure 23 can be continuous or discontinuous in the extension direction. Specifically:

[0052] A feasible implementation method is shown in FIG. Figure 4 The first microstructure 22 and the second microstructure 23 are along Figure 2 The X direction can be continuous.

[0053] A feasible implementation method is shown in FIG. Fig. 9 The first microstructure 22 and the second microstructure 23 are along Figure 8 The X direction may be discontinuous. The first microstructure 22 includes at least two first sub-microstructures 22a, each of which is along Fig. 9The second microstructure 23 includes at least two second sub-microstructures 23a, each of which is arranged along the X direction and the Y direction. Fig. 9 The first sub-microstructure 22a and the second sub-microstructure 23a are arranged in the X direction and extend in the X direction and arranged in the Y direction. Fig. 9 The gaps between two adjacent first sub-microstructures 22a and between two adjacent second sub-microstructures 23a can both increase the transmittance of the optical film 20 in its thickness direction (Z direction in the figure).

[0054] A feasible implementation method is shown in FIG. Fig.10 , the first microstructure 22 is along Fig.10 The second microstructure 23 is continuous in the X direction. Fig.10 The X direction is discontinuous, and the second microstructure 23 includes at least two second sub-microstructures 23a, each of which is along Fig.10 The first sub-microstructure 22a and the second sub-microstructure 23a are arranged in the X direction and extend in the X direction and arranged in the Y direction. Fig. 9 The Y direction is alternately arranged to form groups.

[0055] As shown above, the embodiment of the present application can improve the transmittance of the optical film 20 in its thickness direction (Z direction in the figure) by reasonably setting the length of the first microstructure 22 and the second microstructure 23 in the extension direction, thereby meeting the transmittance requirements of practical applications.

[0056] It should be noted that the length arrangement of the first microstructure 22 and the second microstructure 23 in the extension direction is not only as shown in the above embodiment. It can be reasonably arranged under the condition that the incident light transmission channel or the outgoing light transmission channel provided in the above embodiment needs light reflection, and the embodiments of the present application will not show them one by one.

[0057] Fig.11 It is a top view schematic diagram of another optical film provided by the present application. On the basis of the above embodiment, the optical film 20 can also be divided into regions, and different first microstructures 22 and second microstructures 23 are set for different regions, so that different regions have different reflectivity and transmittance to light.

[0058] Specifically, refer to Fig.11 As shown, the optical film 20 includes at least a first region 20a and a second region 20b, the first region 20a includes a plurality of first microstructures 22, and the second region 20b includes a plurality of first microstructures 22 and a plurality of second microstructures 23. In other words, the first region 20a is provided with a plurality of microstructures along the first surface M1 only. Fig.11The first microstructures 22 extend in the X direction and are arranged in the Y direction. In the second region 20b, a plurality of microstructures are arranged on the first surface M1 along the Y direction. Fig.11 The first microstructure 22 extends in the X direction and is arranged along the Y direction, and a plurality of microstructures are arranged on the second surface M2 along the Y direction. Fig.11 The second microstructure 23 extending in the X direction and arranged along the Y direction performs differential design on the first region 20a and the second region 20b to meet different requirements for reflecting light.

[0059] Among them, the extension length, spacing distance, etc. of the first microstructure 22 in the first area 20a and the second area 20b, and the first microstructure 22 and the second microstructure 23 in the second area 20b can be reasonably set according to specific reflection requirements and transmittance requirements, and the embodiments of the present application are not limited.

[0060] Based on the same inventive concept, the embodiment of the present application further provides a head-up display device, Fig.12 is a structural schematic diagram of another head-up display device provided by the present application, Fig.13 This is a schematic diagram of the structure of a head-up display device provided by the present application applied in a car. Figure 1 The head-up display device HUD includes an image generation unit 10, a projection substrate 30 and the optical film 20 provided in the above embodiment. The optical film 20 is arranged on a side of the projection substrate 30 close to the image generation unit 30, and the second surface M2 of the optical film 20 is attached to the projection substrate 30. Figure 3 , Figure 5-Figure 7 The image light (the first part of the light S1) first enters the first surface M1 of the optical film 20 and then enters the substrate 21, passes through the incident light transmission channel and enters the substrate 21, is reflected by the second surface M2 and output through the outgoing light transmission channel to the outside of the optical film 20, and then reaches the user's observation range to form a virtual image. The first part of the light S1 at a specific angle blocks and absorbs at least part of the second part of the light S2.

[0061] The optical film provided in the embodiment of the present application can be used to reflect image light emitted only from the direction of the image generation unit into the observation range, and to block or absorb light from the angle of the undefined area, thereby reducing the light from the angle of the undefined area that is reflected or scattered by the projection substrate into the human eye within the observation range, thereby improving the ambient light contrast and optimizing the virtual image imaging visual effect.

[0062] refer to Fig.12The head-up display device HUD also includes at least one reflector 40. The image light (the first part of the light S1) output by the image generation unit 10 is reflected by the reflector 40 and then incident on the projection substrate 30. The projection substrate 30 is a vehicle windshield. By reasonably setting the number and position of the reflectors 40, the direction and angle of the image light output by the image generation unit 10 can be adjusted so that the optical film 20 can completely reflect the image light, block the ambient light, and further optimize the virtual image imaging visual effect.

[0063] It should be noted that the projection substrate 30 can be a separately arranged substrate or a vehicle windshield. When the optical film 20 is assembled in the windshield of the vehicle or in a separately arranged substrate, it also has the beneficial effects of the optical film in the above-mentioned embodiment. The similarities can be understood by referring to the above explanation of the optical film, which will not be repeated below.

[0064] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An optical film, characterized in that: include: A substrate, the substrate comprising a first surface and a second surface disposed opposite to each other; A plurality of first microstructures located in the substrate, the first microstructures extending along a first direction and arranged periodically along a second direction, the orthographic projection of the first microstructure on the first section is a first isosceles triangle, the base of the first isosceles triangle is located on the first surface, an incident light transmission channel or an outgoing light transmission channel is formed between two adjacent first microstructures, the first direction intersects the second direction, and the first section is perpendicular to the first direction; Wherein, the light transmittance of the substrate is smaller than the light transmittance of the first microstructure.

2. The optical film according to claim 1, characterized in that: A first portion of light incident on the first surface is incident into the substrate through the incident light transmission channel, and is reflected by the second surface and output through the outgoing light transmission channel to the outside of the optical film; The second portion of light incident on the first surface is absorbed by the first microstructure.

3. The optical film according to claim 1, characterized in that: Also includes a plurality of second microstructures located in the substrate, the second microstructures extending along the first direction, periodically arranged along the second direction, and the orthographic projections of the first microstructures on the second surface and the orthographic projections of the second microstructures on the second surface are alternately arranged along the second direction; The orthographic projection of the second microstructure on the first section is a second isosceles triangle, the base of the second isosceles triangle is located on the second surface, and an incident light transmission channel or an outgoing light transmission channel is formed between two adjacent first microstructures and the second microstructure; Wherein, the light transmittance of the substrate is smaller than the light transmittance of the second microstructure.

4. The optical film according to claim 3, characterized in that: The first microstructure and the second microstructure are made of the same material.

5. The optical film according to claim 3, characterized in that: The orthographic projection of the first microstructure on the second surface has no overlap with the orthographic projection of the second microstructure on the second surface.

6. The optical film according to claim 1, characterized in that: The invention also includes an anti-reflection film arranged on the second surface.

7. The optical film according to claim 6, characterized in that: The refractive index of the anti-reflection film is smaller than the refractive index of the substrate.

8. The optical film according to claim 1, characterized in that: Along the first direction, the first microstructure includes at least two first sub-microstructures.

9. The optical film according to claim 3, characterized in that: Along the first direction, the first microstructure includes at least two first sub-microstructures, and / or the second microstructure includes at least two second sub-microstructures.

10. The optical film according to claim 3, characterized in that: The optical film at least includes a first area and a second area, the first area includes a plurality of the first microstructures, and the second area includes a plurality of the first microstructures and a plurality of the second microstructures.

11. The optical film according to claim 2, characterized in that: The incident angle of the first portion of light is greater than or equal to the first incident angle and less than or equal to the second incident angle; The incident angle of the second portion of light is smaller than the first incident angle, or larger than the second incident angle; The incident angle is the angle between the incident light on the first surface and a normal line perpendicular to the first surface.

12. The optical film according to claim 11, characterized in that: The optical film further comprises a plurality of second microstructures located in the substrate, wherein the orthographic projection of the second microstructure on the first section is a second isosceles triangle; The size of the first isosceles triangle in the second direction is d1, the height of the first isosceles triangle is h1, the height of the second isosceles triangle is h2, the first incident angle is θ1, the size of the substrate in the third direction is T, d1=2T×tanθ1, h1≤T, h2≤T; Wherein, the third direction is the thickness direction of the substrate.

13. The optical film according to claim 11, characterized in that: The optical film further comprises a plurality of second microstructures located in the substrate, wherein the orthographic projection of the second microstructure on the first section is a second isosceles triangle; The period of the first microstructure is P, the size of the first isosceles triangle in the second direction is d1, the height of the first isosceles triangle is h1, the size of the second isosceles triangle in the second direction is d2, the height of the second isosceles triangle is h2, the second incident angle is θ2, the size of the substrate in the third direction is T, d1<2(PT×tanθ2), h2=P / (2tanθ2), d2≤P, Wherein, the third direction is the thickness direction of the substrate.

14. The optical film according to claim 11, characterized in that: The optical film further comprises a plurality of second microstructures located in the substrate, wherein the orthographic projection of the second microstructure on the first section is a second isosceles triangle; The period of the first microstructure is P, the size of the first isosceles triangle in the second direction is d1, the height of the first isosceles triangle is h1, the size of the second isosceles triangle in the second direction is d2, the height of the second isosceles triangle is h2, the second incident angle is θ2, and the size of the substrate in the third direction is T, d1=2(PT×tanθ2), h2≤P / (2tanθ2), wherein the third direction is the thickness direction of the substrate.

15. The optical film according to claim 11, characterized in that: The period of the first microstructure is P, the size of the first isosceles triangle in the second direction is d1, the height of the first isosceles triangle is h1, the second incident angle is θ2, and the size of the substrate in the third direction is T, d1=2(PT×tanθ2), wherein the third direction is the thickness direction of the substrate.

16. The optical film according to claim 11, characterized in that: The incident angle of the first part of light is greater than or equal to 10° and less than or equal to 30°; The incident angle of the second portion of light is less than 10° or greater than 30°.

17. A head-up display device, characterized in that: The optical film comprises an image generating unit, a projection substrate and the optical film according to any one of claims 1 to 16, wherein the optical film is arranged on a side of the projection substrate close to the image generating unit.

18. The head-up display device according to claim 17, characterized in that: It also includes at least one reflecting mirror, and the image light output by the image generating unit is incident on the projection substrate after being reflected by the reflecting mirror.

19. The head-up display device according to claim 17, characterized in that: The projection substrate is a vehicle windshield.

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