Backlight assembly and head-up display system

Abstract

Embodiments of the present application provide a backlight assembly and a head-up display system, which are used to make the backlight assembly provide two different light paths. The backlight assembly comprises: a light source configured to emit light; a birefringent component located on one side of the light source and configured to divide the light incident on the birefringent component into first polarized light and second polarized light, the vibration direction of the first polarized light being perpendicular to the vibration direction of the second polarized light; the birefringent component comprises a first region and a second region, the first polarized light corresponding to the first region, and the second polarized light corresponding to the second region, wherein the first region and the second region at least partially do not overlap in the emission direction of the light; a first light adjusting component located on the side of the birefringent component away from the light source; the first polarized light propagates along a first direction after being emitted through the first light adjusting component; the second polarized light propagates along a second direction, and the first direction intersects the second direction.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a backlight assembly and a head-up display system. Background Technology

[0002] With the continuous development of display technology, head-up displays (HUDs) have gradually been applied in the field of transportation, such as automobiles. HUD systems can project information such as vehicle speed, fuel consumption, and necessary navigation information into the windshield in front of the driver's seat in the form of graphics and / or characters. This eliminates the need for the driver to look down at the instrument panel to check information such as speed and fuel consumption, thus improving driving safety.

[0003] Conventional HUD optical paths are relatively simple. Currently, for optical systems including HUDs that can simultaneously display two virtual images at near and far distances, two optical paths are generally required. This is usually achieved by adding additional backlight components, which results in high power consumption and significant heat generation. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a backlight assembly and a head-up display system, which enable a set of backlight assemblies to provide two different optical paths, thereby reducing the power consumption of the backlight assembly and the heat generated by the backlight assembly during operation.

[0005] On one hand, embodiments of the present invention provide a backlight assembly, including:

[0006] A light source, used to emit light;

[0007] A birefringent component, located on one side of the light source, is used to split the light incident on the birefringent component into a first polarized light and a second polarized light, wherein the vibration direction of the first polarized light is perpendicular to the vibration direction of the second polarized light.

[0008] The birefringent component includes a first region and a second region, wherein the first polarized light corresponds to the first region and the second polarized light corresponds to the second region, and the first region and the second region do not overlap at least partially in the direction of light emission.

[0009] A first dimming component is located on the side of the birefringent component away from the light source; the first polarized light propagates along a first direction after being emitted from the first dimming component; the second polarized light propagates along a second direction, and the first direction intersects with the second direction.

[0010] On the other hand, embodiments of the present invention provide a head-up display system including the backlight assembly described above.

[0011] The backlight assembly and head-up display system provided in this embodiment of the invention, by setting the backlight assembly to include a birefringent component, can use the birefringent component to split the light emitted by the light source into a first polarized light and a second polarized light, and make the first polarized light and the second polarized light emit from a first region and a second region respectively.

[0012] Furthermore, by providing a first dimming component, the propagation direction of the first polarized light incident on the first dimming component can be adjusted, causing the propagation directions of the first polarized light emitted from the first dimming component and the second polarized light to intersect. That is, the propagation directions of the first polarized light emitted from the first dimming component and the second polarized light are not parallel, thus allowing the first and second polarized lights to exit the backlight assembly along different propagation directions. Subsequently, the first and second polarized lights propagating in different directions can be utilized separately. Based on this arrangement, there is no need to increase the number of backlight components, which reduces the power consumption of the backlight components and the heat generated by the backlight components during operation.

[0013] Furthermore, by ensuring that the first region and the second region do not overlap at least partially in the direction of light propagation, the first dimming component can be used to adjust the direction of light propagation of the first polarized light while also preventing the direction of light propagation of the second polarized light from being affected by the first dimming component. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 A cross-sectional schematic diagram of a backlight assembly on a first cross section is provided in an embodiment of the present invention;

[0016] Figure 2 for Figure 1 A schematic diagram of an optical path;

[0017] Figure 3 for Figure 1 Another optical path diagram;

[0018] Figure 4 This is a schematic diagram of another backlight assembly and its optical path provided in an embodiment of the present invention;

[0019] Figure 5 A schematic diagram of a light source, a birefringent component, a second dimming component, and related optical paths in another backlight assembly provided in an embodiment of the present invention;

[0020] Figure 6 A schematic diagram of a first dimming component and its optical path is provided for an embodiment of the present invention;

[0021] Figure 7 A schematic diagram of another first dimming component and its optical path provided in an embodiment of the present invention;

[0022] Figure 8 A schematic diagram of another backlight assembly and its optical path provided in an embodiment of the present invention;

[0023] Figure 9 A schematic diagram of another backlight assembly and its optical path provided in an embodiment of the present invention;

[0024] Figure 10 A schematic diagram of another backlight assembly and its optical path provided in an embodiment of the present invention;

[0025] Figure 11 A schematic diagram of another backlight assembly and its optical path provided in an embodiment of the present invention;

[0026] Figure 12 A schematic diagram of another backlight assembly and its optical path provided in an embodiment of the present invention;

[0027] Figure 13 This is a schematic diagram of a first dimming component and a connecting part provided in an embodiment of the present invention;

[0028] Figure 14 A schematic diagram of a head-up display system provided in an embodiment of the present invention;

[0029] Figure 15 This is a schematic diagram of another head-up display system provided in an embodiment of the present invention. Detailed Implementation

[0030] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0031] This invention provides a backlight assembly, combined with Figure 1 and Figure 2 As shown, Figure 1 This is a cross-sectional schematic diagram of a backlight assembly on a first cross section, provided in an embodiment of the present invention. Figure 2 for Figure 1 A schematic diagram of an optical path is shown, in which the backlight assembly includes a light source 1, a birefringent component 21, and a first dimming component 31. The light source 1 is used to emit light; for example, the light emitted by the light source 1 includes natural light.

[0032] like Figure 1As shown, the birefringent component 21 is located on one side of the light source 1. In this embodiment of the invention, light rays incident on the birefringent component 21 are split into first polarized light and second polarized light with mutually perpendicular polarization directions inside the birefringent component 21. The first polarized light and the second polarized light propagate along different light propagation directions within the birefringent component 21. Figure 1 and Figure 2 As shown, the normal F of the incident surface of the birefringent component 21 and the optical axis 20 are both parallel to the first cross-section. Furthermore, the optical axis 20 of the birefringent component 21 intersects the incident surface of the birefringent component 21. Subsequently, the first polarized light and the second polarized light exit from the birefringent component 21.

[0033] For example, the first polarized light includes extraordinary light (e-light) whose vibration direction is parallel to the first cross-section, and the second polarized light includes ordinary light (o-light) whose vibration direction is perpendicular to the first cross-section. Figure 2 In the diagram, the vibration direction of the first polarized light is indicated by a short horizontal line, and the vibration direction of the second polarized light is indicated by a dot.

[0034] like Figure 1 and Figure 2 As shown, the birefringent component 21 includes a first region A1 and a second region A2. First polarized light corresponds to the first region A1, and second polarized light corresponds to the second region A2. The first region A1 and the second region A2 do not overlap at least partially in the direction of light propagation. Figure 1 As shown, the exit surface of the birefringent component 21 includes the first region A1 and the second region A2 mentioned above; the first polarized light corresponds to the first region A1, that is, the first polarized light is emitted from the first region A1; the second polarized light corresponds to the second region A2, that is, the second polarized light is emitted from the second region A2.

[0035] When the backlight assembly is working, light source 1 emits light, such as... Figure 2 As shown, light enters the birefringent component 21 along a preset direction h0, and is split into a first polarized light and a second polarized light with mutually perpendicular polarization directions and intersecting propagation directions inside the birefringent component 21. That is, the propagation directions of the first polarized light and the second polarized light are not parallel. Subsequently, the first polarized light and the second polarized light corresponding to this light are emitted from different positions on the exit surface of the birefringent component 21 along the preset direction h0. Figure 2 The incident surface of the birefringent component 21 is illustrated by a preset direction h0 perpendicular to it. Figure 2 As shown, the first region A1 is the region on the exit surface of the birefringent component 21 that includes the first polarized light, and the second region A2 is the region on the exit surface of the birefringent component 21 that includes the second polarized light. The first region A1 and the second region A2 do not overlap at least partially in the preset direction h0.

[0036] It should be noted that, Figure 2 This illustration uses only one of the multiple rays emitted by light source 1. Besides this ray, light source 1 can emit multiple other rays. Correspondingly, there are also multiple first-polarized rays and second-polarized rays emitted from the birefringent component 21. Therefore, the first region A1 can include multiple first-polarized rays corresponding to different incident rays, and the second region A2 can include multiple second-polarized rays corresponding to different incident rays.

[0037] like Figure 1 and Figure 2 As shown, the first dimming component 31 is located on the side of the birefringent component 21 away from the light source 1. Exemplarily, the first dimming component 31 is positioned corresponding to the first region A1, that is, the first dimming component 31 is located on the optical path of the first polarized light emitted from the birefringent component 21, to receive the first polarized light emitted from the birefringent component 21, and adjust the propagation direction of the first polarized light so that the first polarized light entering the first dimming component 31 along a preset direction h0 propagates along the first direction h1 after passing through the first dimming component 31. The first direction h1 is the emission direction of the first polarized light emanating from the first dimming component 31. The first direction h1 intersects the preset direction h0, that is, the first direction h1 is not parallel to the preset direction h0.

[0038] In embodiments of the present invention, such as Figure 1 As shown, the second polarized light propagates along the second direction h2, and the first direction h1 intersects with the second direction h2, that is, the first direction h1 and the second direction h2 are not parallel.

[0039] In this embodiment of the invention, by setting a birefringent component 21 in the backlight assembly, the light emitted by the light source 1 can be divided into a first polarized light and a second polarized light by the birefringent component 21, and the first polarized light and the second polarized light can be emitted from the first region A1 and the second region A2 respectively.

[0040] Furthermore, by providing a first dimming component 31, the propagation direction of the first polarized light incident on the first dimming component 31 can be adjusted, causing the propagation directions of the first polarized light emitted from the first dimming component 31 to intersect with those of the second polarized light. That is, the propagation directions of the first polarized light emitted from the first dimming component 31 and the second polarized light are not parallel, thus allowing the first and second polarized lights to exit the backlight assembly along different propagation directions. Subsequently, the first and second polarized lights propagating in different directions can be utilized separately. Based on this arrangement, there is no need to increase the number of backlight components, which reduces the power consumption of the backlight components and the heat generated during operation.

[0041] Furthermore, by ensuring that the first region A1 and the second region A2 do not overlap at least partially in the direction of light propagation, the first dimming component 31 can be used to adjust the direction of light propagation of the first polarized light while also preventing the direction of light propagation of the second polarized light from being affected by the first dimming component 31.

[0042] For example, such as Figure 3 As shown, Figure 3 for Figure 1 Another optical path diagram shows that the birefringent component 21 includes a first surface 210 located on the side of the birefringent component 21 closer to the light source 1. The length of the first region A1 on the first cross section is d11, and the length of the second region A2 on the first cross section is d12. In this embodiment of the invention, the first surface 210 can be configured to include multiple spaced incident regions C, with the length of the incident region C on the first cross section being d21, and the distance between two adjacent incident regions C being d22. The incident regions C are used to receive light emitted by the light source 1, and the region between two adjacent incident regions C is not used to receive light emitted by the light source 1. That is, the portion of the first surface 210 located within the incident regions C is the incident surface of the birefringent component 21.

[0043] like Figure 3 As shown, the length of the birefringent component 21 in the direction perpendicular to the first surface 210 is T; the angle between the propagation directions of the first polarized light and the second polarized light in the birefringent component 21 is β; where 0 < d21 ≤ Ttanβ ≤ d22.

[0044] Based on this configuration, the first region A1 and the second region A2 can be set to not overlap in the direction of light propagation, so as to avoid the situation where a certain region in the birefringent component 21 emits both first polarized light and second polarized light, that is, the first polarized light and the second polarized light cannot be separated in space. While adjusting the direction of light propagation of the first polarized light using the first dimming component 31, the direction of light propagation of the second polarized light can be prevented from being affected by the first dimming component 31.

[0045] When the birefringent component includes a positive uniaxial crystal When the birefringent component includes a negative uniaxial crystal Where, n e n is the principal refractive index of the e-ray of the birefringent component 21. o Let α be the refractive index of the o-ray of the birefringent component 21, and α be the angle between the optical axis of the birefringent component 21 and the normal to the e-ray wave. The normal to the e-ray wave can be parallel to the direction of propagation of the o-ray. Figure 2 and Figure 3The birefringent component 21 includes a positive uniaxial crystal, and the direction of light propagation h0 of the incident light is perpendicular to the incident surface of the birefringent component 21.

[0046] Combination Figure 3 As shown, Figure 3 Assuming multiple incident regions C, including a first incident region C1 and a second incident region C2, with both regions having a length of d21 on a first cross section, the first incident beam directed towards the first incident region C1 includes a first incident ray X11 and a second incident ray X12. The first incident ray X11 is directed towards the boundary of the first incident region C1 away from the boundary of the second incident region C2, while the second incident ray X12 is directed towards the boundary of the first incident region C1 near the boundary of the second incident region C2. The second incident beam directed towards the second incident region C2 includes a third incident ray X21 and a fourth incident ray X22. The third incident ray X21 is directed towards the boundary of the second incident region C2 near the boundary of the first incident region C1, while the fourth incident ray X22 is directed towards the boundary of the second incident region C2 away from the boundary of the first incident region C1. Multiple incident rays in the first and second incident beams are split into first polarized light and second polarized light inside the birefringent component 21, and then the first polarized light and second polarized light are emitted from the birefringent component 21.

[0047] For example, such as Figure 3 As shown, the first region A1 includes a first sub-region A11 and a third sub-region A12, and the second region A2 includes a second sub-region A21 and a fourth sub-region A22. The multiple first polarized rays included in the first sub-region A11 and the multiple second polarized rays included in the second sub-region A21 are both generated by incident rays from the first incident region C1. The multiple first polarized rays included in the third sub-region A12 and the multiple second polarized rays included in the fourth sub-region A22 are both generated by incident rays from the second incident region C2.

[0048] Optionally, in embodiments of the present invention, d21 can be set to Ttanβ, so that the first region A1, which includes the first polarized light, and the second region A2, which includes the second polarized light, are exactly separated by the light rays incident into the same incident region C. Figure 3 For example, for multiple rays in the first incident beam that enter the birefringent component 21 through the first incident region C1, based on the setting of d21=Ttanβ, the exit position of the first polarized light P111 generated by the first incident ray X11 and the exit position of the second polarized light P212 generated by the second incident ray X12 can coincide exactly, that is, the first sub-region A11 and the second sub-region A21 can just not overlap in the direction of light propagation.

[0049] Alternatively, in embodiments of the present invention, d21 < Ttanβ can be set, thus allowing a distance to exist between the first region A1, which includes the first polarized light, and the second region A2, which includes the second polarized light, formed by light rays incident on the same incident region C. (Combined) Figure 4 As shown, Figure 4 This is a schematic diagram of the optical path of another backlight assembly provided in an embodiment of the present invention, wherein d21 < Ttanβ. Figure 4 As shown, in this embodiment of the invention, by setting d21 < Ttanβ, the exit position of the second polarized light P212 generated by the second incident light X12 can be located on the side away from the exit position of the first polarized light P111 generated by the first incident light X11, and the exit position of the first polarized light P111 generated by the first incident light X11 can be located on the side away from the exit position of the second polarized light P212 generated by the second incident light X12, respectively. There is a distance Δd1 between the first sub-region A11 and the second sub-region A21. Within this region, neither the first polarized light nor the second polarized light is emitted. That is, the first sub-region A11 and the second sub-region A21 can be completely separated without overlapping in the direction of light propagation.

[0050] For example, in an embodiment of the present invention, d22 can be set to Ttanβ, so that the first region A1 and the second region A2, which correspond to the two adjacent incident regions C, are exactly separated. Continuing to refer to... Figure 3 Where d22=Ttanβ, it can be seen that the exit position of the first polarized light P112 generated by the second incident ray X12 and the exit position of the second polarized light P221 generated by the third incident ray X21 coincide exactly. That is, the first sub-region A11 and the fourth sub-region A22 do not overlap in the direction of light propagation.

[0051] Alternatively, in embodiments of the present invention, Ttanβ < d22 can be set so that there is a distance between the first region A1, which includes first polarized light, and the second region A2, which includes second polarized light, formed by light rays incident on different incident regions C. (Combined) Figure 4 As shown, where Ttanβ < d22, it can be seen that the exit positions of the first polarized light P112 and the second polarized light P221 are staggered, and there is a distance Δd2 between the first sub-region A11 and the fourth sub-region A22. Within this region, neither the first polarized light nor the second polarized light is emitted. That is, the first sub-region A11 and the fourth sub-region A22 can be completely separated without overlapping in the direction of light propagation.

[0052] It should be noted that, Figure 3 and Figure 4The illustration showing that the lengths of the first incident region C1 and the second incident region C2 on the first cross section are equal is merely illustrative. In embodiments of the present invention, the lengths of the first incident region C1 and the second incident region C2 on the first cross section can also be unequal. For example, one of them can be of length Ttanβ, and the other can be shorter than Ttanβ. Alternatively, they can be two different values ​​less than Ttanβ. The present invention does not limit this approach.

[0053] For example, such as Figure 3 and Figure 4 As shown, in this embodiment of the invention, d11 = d12 can be set. With this configuration, when the number of first regions A1 and the number of second regions A2 are the same, the light-emitting areas of the first polarized light and the second polarized light emitted by the birefringent component 21 can be made the same.

[0054] For example, such as Figure 5 As shown, Figure 5 This is a schematic diagram of another backlight assembly and its optical path provided in an embodiment of the present invention. The backlight assembly further includes a second dimming component 4 located between the light source 1 and the birefringent component 21. The second dimming component 4 is used to adjust the light incident on the birefringent component 21 to include multiple incident beams corresponding to the incident regions C. The incident beams include multiple incident rays, and the light does not shine into the gap between two adjacent incident regions C. Figure 5 The example illustrates how incident light rays are directed along the preset direction h0 toward the first surface 210 of the birefringent component 21.

[0055] The second dimming component 4 can split the light incident on the birefringent component 21 into multiple incident beams spaced apart, thereby ensuring that the first polarized light and the second polarized light emitted from the birefringent component 21 are respectively located in the first region A1 and the second region A2, which do not overlap at least partially. This configuration eliminates the need for structural adjustments to the birefringent component 21 and is easy to implement.

[0056] For example, such as Figure 5 As shown, the second dimming component 4 includes multiple microlens groups 40, each including a convex lens 41 and a concave lens 42. The convex lens 41 is located on the side of the concave lens 42 away from the birefringent component 21; the concave lens 42 is positioned corresponding to the incident area C of the birefringent component 21. When the backlight assembly is working, the light emitted from the light source first passes through the convex lens 41, which can converge the light rays toward the object focal point of the concave lens 42. The concave lens 42 can then convert the converged light rays into parallel light that is directed toward the incident area C of the birefringent component 21. Figure 5As shown, no light is emitted between two adjacent concave lenses 42. That is, the arrangement of the microlens group 40, including the convex lens 41 and the concave lens 42, allows the light emitted from the light source 1 to be adjusted into a narrow beam of parallel light corresponding to each incident region C of the birefringent component 21 after passing through the microlens group 40. This ensures that the first region A1 and the second region A2 of the birefringent component 21 do not overlap at least partially in the direction of light propagation. Furthermore, while adjusting the direction of light propagation of the first polarized light using the first dimming component 31, the direction of light propagation of the second polarized light is prevented from being affected by the first dimming component 31.

[0057] Optional, such as Figure 5 As shown, in this embodiment of the invention, the light source 1 can be configured to include multiple sub-light sources 10, each corresponding to a different microlens group 40. Optionally, the sub-light source 10 includes a strip-shaped light source, the extension direction of which is perpendicular to the first cross-section. Alternatively, in this embodiment of the invention, the sub-light source 10 can be configured as a point-shaped light source, and the multiple sub-light sources 10 can be arranged in an array in a plane parallel to the incident surface of the birefringent component 21.

[0058] For example, the concave lens 42 includes a first effective region, which is the area of ​​the concave lens 42 that can transmit a light beam. Optionally, in embodiments of the present invention, all positions of the concave lens 42 can be configured to transmit a light beam, that is, the width of the first effective region on the first cross-section is equal to the width of the concave lens 42 on the first cross-section. Alternatively, in embodiments of the present invention, a portion of the concave lens 42 can be designated as the first effective region that can transmit a light beam, and another portion as a non-effective region that does not transmit a light beam, that is, the width of the first effective region on the first cross-section is less than the width of the concave lens 42 on the first cross-section. Figure 5 As shown, the concave lens 42 is configured to transmit light beams at all positions, i.e., the width of the first effective region on the first cross section is equal to the width of the concave lens 42 on the first cross section. The width of the first effective region on the first cross section is d31, and the width of the convex lens 41 on the first cross section is d41. The width directions of both the concave lens 42 and the convex lens 41 are perpendicular to the propagation direction of the incident light. The distance between two adjacent concave lenses 42 is d32, and two adjacent convex lenses 41 are in contact. Here, d41 > d31 = d21; d32 = d22. This design allows the light-emitting area of ​​the concave lens 42 to be equal to the area of ​​the incident region C of the birefringent component 21. Therefore, by correspondingly setting the concave lens 42 to the incident region C of the birefringent component 21, and by correspondingly setting the gap between two adjacent concave lenses 42 to the gap between two adjacent incident regions C, light rays emitted from the concave lens 42 can all reach the incident region C of the birefringent component 21.

[0059] For example, the length of the incident surface of the first dimming component 31 on the first cross section is a, where a ≥ d11 > 0. Figure 3 The diagram uses a = d11 as an example. Figure 4 Using a > d11 as an example.

[0060] By setting a = d11, and by correspondingly setting the incident surface 311 of the first dimming component 31 and the first region A1 of the birefringent component 21 in the direction of light propagation, the first polarized light emitted from the first region A1 of the birefringent component 21 can be precisely incident into the first dimming component 31, without having to set the size of the first dimming component 31 too large.

[0061] Or, such as Figure 4 As shown, when there is a distance between the first region A1 and the second region A2, in this embodiment of the invention, by setting a > d11, a portion of the incident surface of the first dimming component 31 can be set to correspond to the first region A1, and the remaining portion can be set to correspond to the gap between the first region A1 and the second region A2, thereby ensuring that the first dimming component 31 can receive all the first polarized light emitted from the first region A1.

[0062] For example, the distance between two adjacent first dimming components 31 is c, where c ≥ d12 > 0. Figure 3 The diagram uses c = d12 as an example. Figure 4 Using c > d12 as an example. For instance, in an embodiment of the present invention, the region between two adjacent first dimming components 31 can be configured to correspond to the second region A2 of the birefringent component 21, so that the second polarized light emitted from the second region A2 can bypass the first dimming component 31 and be directed to the region between two adjacent first dimming components 31.

[0063] For example, such as Figure 2 As shown, the first dimming component 31 includes an incident surface 311, a second surface 312, and a third surface 313. The second surface 312 intersects the incident surface 311, and the included angle between them is θ1, where 0° < θ1 < 90°. The third surface 313 intersects the incident surface 311 and is perpendicular to it. The third surface 313 intersects the second surface 312. After the first polarized light enters the first dimming component 31 through the incident surface 311, the first polarized light can be reflected at the second surface 312, such as... Figure 2 As shown, the reflected ray has an incident angle θ i The light is directed toward the third surface 313 and refracted at an angle θ. tThe light is emitted from the third surface 313. In this embodiment of the invention, by making the third surface 313 perpendicular to the incident surface 311, while using the second surface 312 to receive the incident first polarized light, the first polarized light entering the first dimming component 31 via the incident surface 311 is prevented from directly hitting the third surface 313, thereby preventing the first dimming component 31 from emitting first polarized light with two different propagation directions.

[0064] For example, such as Figure 1 and Figure 2 As shown, the backlight assembly also includes a first portion 5. One portion of the first portion 5 is located on the side of the second surface 312 away from the first dimming component 31, and the other portion of the first portion 5 is located on the side of the third surface 313 away from the first dimming component 31. The first portion 5 is in contact with both the second surface 312 and the third surface 313. That is, the second surface 312 and the third surface 313 form the interface between the first dimming component 31 and the first portion 5. In this embodiment of the invention, the refractive index of the first dimming component 31 is n1, and the refractive index of the first portion 5 is n2, where n2 < n1.

[0065] Optionally, embodiments of the present invention can make While the first polarized light reflected by the second surface 312 is refracted by the third surface 313 and exits through the first dimming component 31, as Figure 2 As shown, the first polarized light can undergo total internal reflection on the second surface 312, thereby preventing the first polarized light from exiting the first dimming component 31 via the second surface 312. In other words, based on this arrangement, while using the third surface 313 as the exiting surface of the first dimming component 31, the second surface 312 is prevented from also serving as the exiting surface of the first dimming component 31, thus allowing the first dimming component 31 to emit only the first polarized light with a single propagation direction. The propagation direction of the first polarized light emitted from the third surface 313 is the aforementioned first direction h1.

[0066] Furthermore, based on this configuration, the refraction angle θ emitted from the third surface 313 can also be adjusted. t Greater than the incident angle θ i This increases the angle between the light emitted from the third surface 313 and the incident surface 311. When multiple first dimming components 31 are provided in the backlight assembly, it helps to prevent the first polarized light emitted from the third surface 313 of one of the first dimming components 31 from being reflected and refracted by another first dimming component 31, thus avoiding beam splitting.

[0067] Furthermore, by including a uniform medium in the first part 5, the propagation direction of the second polarized light after passing through the first part 5 remains unchanged, that is, the second polarized light continues to propagate along the preset direction h0 after passing through the first part 5.

[0068] Optionally, when manufacturing the backlight assembly, the first dimming component 31 can be placed in an environment with a uniform medium, which is the first part 5.

[0069] For example, such as Figure 3 and Figure 4 As shown, the length of the incident surface 311 of the first dimming component 31 on the first cross section is a, and the length of the third surface 313 on the first cross section is b; a < b, so that the first polarized light can be emitted from the third surface 313 and exit the first dimming component 31.

[0070] like Figure 3 and Figure 4 As shown, the incident surface 311 of the first dimming component 31 includes a second effective region B1, which corresponds to the first region A1 in a preset direction h0. In this embodiment of the invention, the area of ​​the second effective region B1 is less than or equal to the area of ​​the incident surface 311. Figure 4 As illustrated, the area of ​​the second effective region B1 is smaller than the area of ​​the incident surface 311, for example... Figure 4 As shown, there is a first distance t1 between the first boundary of the incident surface 311 and the second effective region B1, and a second distance t2 between the second boundary of the incident surface 311 and the second effective region B1, where t1 > 0 and t2 > 0. The first boundary is the boundary of the incident surface 311 on the side closer to the second surface 312, and the second boundary is the boundary of the incident surface 311 on the side closer to the third surface 313. Figure 3 The area of ​​the second effective region B1 is equal to the area of ​​the incident surface 311, and the boundary of the incident surface 311 coincides with the boundary of the second effective region B1, that is, the first distance and the second distance are both 0, as an illustration.

[0071] For example, b satisfies:

[0072]

[0073] in,

[0074]

[0075] c is the distance between two adjacent first dimming components 31.

[0076] For example, when the second boundary of the incident surface 311 coincides with the boundary of the second effective region B1, that is, when t2 = 0, the embodiment of the present invention can make

[0077]

[0078] Combination Figure 6 and Figure 7 As shown, Figure 6 and Figure 7 This is a schematic diagram of two first dimming components and their optical paths provided in embodiments of the present invention. Each diagram uses two first dimming components as examples, labeled 31_1 and 31_2 respectively. Figure 6 The diagram illustrates the overlap between the second boundary of the incident surface 311 and the boundary of the second effective region B1, where a first distance t1, t1 > 0, exists between the first boundary of the incident surface 311 and the second effective region B1. Figure 7 The first and second boundaries of the incident surface 311 coincide with the boundary of the second effective region B1, i.e., the first and second distances mentioned above are both equal to 0. In this embodiment of the invention, by letting b satisfy the above formula (3), tanθ can be set... t = (bh) / (a+c); where, h = t1tanθ1 + (a-t1)tanθ i b = atanθ1, n2sinθ t =n1sinθ i In other words, it can make Figure 6 and Figure 7 The refracted ray Y11 emitted from the first dimming component 31_1 passes over the endpoint of the first dimming component 31_2, and after passing over the endpoint of the first dimming component 31_2, the refracted ray Y11 coincides with the refracted ray Y22. That is, there can be no gap between the first polarized beam emitted from the first dimming component 31_1 and the first polarized beam emitted from the first dimming component 31_2. With this design, when the sub-light source 10 is set as a strip light source extending in a direction perpendicular to the first cross-section, there is no need to set up a component for expanding the first polarized beam, thereby improving the light emission uniformity of the first polarized light emitted by the backlight assembly.

[0079] For example, in an embodiment of the present invention, n1 = 1.5 and n2 = 1. In this case, the critical angle θ of the first polarized light incident on the second surface 312 is... c Satisfy: θ c =arcsin(n2 / n1) = 41.81°.

[0080] Based on the setting method provided in the embodiments of the present invention, when a = c and t1 = 0, substituting n1 and n2 into the above formula (2) yields: X = -0.65; b / a = 1.84; that is, tanθ1 = b / a = 1.84, and θ1 = 61.48° > θ c Therefore, based on the configuration provided in this embodiment of the invention, after the first polarized light is perpendicularly incident on the incident surface 311, the first polarized light can undergo total internal reflection on the second surface 312, thereby preventing the first polarized light from exiting the first dimming component 31 from the second surface 312.

[0081] Furthermore, according to the Fresnel equation, the polarization angle θ of the third surface 313 can be calculated. p Satisfy: θ p =arctan(n2 / n1) = 33.69°.

[0082] Based on the above formulas (2) and (3), the incident angle θ of the first polarized light actually incident on the third surface 313 can be calculated. i tanθ i =-X=0.65, θ can be calculated. i =arctan0.65 = 33.02°; It can be seen that, based on the setting method of this embodiment, the actual incident angle θ of the light rays that are totally reflected by the second surface 312 and incident on the third surface 313 can be made... i Approximately close to the polarization angle of the third surface 313, when linearly polarized light with its vibration direction within the incident plane is incident on the third surface 313, the linearly polarized light almost completely exits from the third surface 313, where the incident plane is jointly determined by the direction of light propagation and the normal to the third surface 313. Therefore, based on the arrangement provided in this embodiment of the invention, it is beneficial to increase the luminous flux of the first polarized light refracted from the third surface 313 and suppress the reflection of the first polarized light by the third surface 313.

[0083] For example, embodiments of the present invention can make tanθ i =tanθ p When a = c and t1 = 0, we can calculate n1 / n2 = 1.53 using the formula (2) above. In this case, only refracted light will be emitted from the third surface 313, and the reflected light will disappear. This can increase the light flux of the first polarized light refracted from the third surface 313 and suppress the reflection of the first polarized light by the third surface 313.

[0084] Combination Figure 8 As shown, Figure 8 This invention provides another backlight assembly and its schematic diagram. In this embodiment, a first beam expander 61 can be provided in the backlight assembly. Along the first direction h1, the first beam expander 61 is located on the side of the third surface 313 away from the first dimming component 31. The first beam expander 61 is used to expand the first polarized beam emitted from the third surface 313 of the first dimming component 31. When there is a gap G1 between the light propagating along the first direction h1 emitted from the third surfaces 313 of two adjacent first dimming components 31, this invention can increase the width of the first polarized beam by providing the first beam expander 61, such as... Figure 8 As shown, the extension line of the light emitted from the first beam expander 61 can pass through the gap G1 between two adjacent first polarized beams, which can make the first polarized light emitted from the backlight assembly more uniform.

[0085] When the first beam expander 61 is provided, for example, such as Figure 8 As shown, in this embodiment of the invention, t1≥0, t2>0, and b satisfies formula (1). With this setting, while increasing the width of the first polarized beam and making the first polarized light emitted from the backlight assembly more uniform, it can prevent the first polarized light emitted from the first dimming component 31_1 from hitting the first dimming component 31_2, and can also reduce the accuracy requirements of the dimensions of the first dimming component 31.

[0086] Or, such as Figure 9 As shown, Figure 9 This invention provides another backlight assembly and its schematic diagram. When the first beam expander 61 is provided, this embodiment can also set t1≥0, so that the second boundary of the incident surface 311 coincides with the boundary of the second effective region B1, that is, set t2=0. In this case, this embodiment can set...

[0087]

[0088] In this embodiment of the invention, by making b satisfy formula (4), on the one hand, the first polarized light emitted from the first dimming component 31_1 can be prevented from hitting the first dimming component 31_2, and on the other hand, the accuracy requirements for the size of the first dimming component 31 can be reduced.

[0089] In embodiments of the present invention, such as Figure 8 and Figure 9 As shown, the first polarized light incident on the first beam expander 61 and the first polarized light emitted from the first beam expander 61 both propagate along the first direction h1.

[0090] For example, such as Figure 8 and Figure 9 As shown, the first beam expander 61 includes a diverging unit 611 and a collimating unit 612 arranged along the first direction h1. The diverging unit 611 is used to diverge the first polarized beam emitted from the first dimming unit 31 to form a first polarized diverging beam with a large width. The collimating unit 612 is used to collimate the first polarized diverging beam.

[0091] For example, such as Figure 8 and Figure 9 As shown, the divergence unit 611 includes a first convex lens, and the collimation unit 612 includes a second convex lens. The centers of the first and second convex lenses are arranged along a first direction h1, and the second convex lens is located on the side of the first convex lens away from the first dimming component 31. Figure 8 and Figure 9As shown, the optical axes of both the first and second convex lenses are parallel to the first direction h1. The distance between the center of the second convex lens and the center of the first convex lens is greater than the focal length of the first convex lens. The first polarized beam converges and then diverges after passing through the first convex lens, and then becomes a parallel beam after passing through the second convex lens. Figure 8 and Figure 9 As shown, the width of the first convex lens is smaller than the width of the second convex lens, wherein the width of the convex lens is perpendicular to the first direction h1, and there is a gap between two adjacent first convex lenses; two adjacent second convex lenses are in contact with each other.

[0092] It should be noted that, Figure 8 and Figure 9 The arrangement of the first and second convex lenses is merely illustrative. This embodiment of the invention does not specifically limit the structure of the first beam expander 61. Any other structure that can increase the width of the first polarized beam is within the scope of protection claimed in this embodiment of the invention.

[0093] Optional, combined Figure 10 As shown, Figure 10 This is another backlight assembly and its schematic diagram provided by an embodiment of the present invention. First polarized light emitted from the birefringent component 21 enters the first dimming component 31 at a preset direction h0 via the incident surface 311 of the first dimming component 31. The embodiment of the present invention can also... Based on this configuration, total internal reflection of the incoming first polarized light at the second surface 312 can be avoided. That is, the second surface 312 can be used as the output surface of the first dimming component 31, so that the first polarized light is emitted from the second surface 312 in the first direction h1.

[0094] For example, embodiments of the present invention may allow: Based on this, the first polarized light can be directed onto the second surface 312 at a polarization angle. When linearly polarized light with its vibration direction within the incident plane is incident on the second surface 312, the reflected light will disappear, and only refracted light will exit from the second surface 312. The incident plane is determined by the direction of light propagation and the normal to the second surface 312. Therefore, based on the above arrangement, the first polarized light can be refracted entirely along the first direction h1 on the second surface 312 without reflection. This avoids the first polarized light reflected by the second surface 312 from the third surface 313 and exiting from there. In other words, based on this arrangement, only the second surface 312 can be used as the exit surface of the first dimming component 31, preventing the first polarized light from also exiting from the third surface 313, thus avoiding optical path complexity.

[0095] Optional, such as Figure 10As shown, the backlight assembly also includes a second beam expander 62, which is used to expand the first polarized beam emitted from the second surface 312 of the first dimming component 31. When there is a gap G2 between the first polarized beams emitted from the second surfaces 312 of two adjacent first dimming components 31, the embodiment of the present invention can increase the width of the first polarized beam by providing the second beam expander 62, such as... Figure 10 As shown, the extension line of some of the light rays emitted from the second beam expander 62 can pass through the gap G2 between two adjacent first polarized beams, which helps to make the first polarized light emitted from the backlight assembly more uniform.

[0096] For example, such as Figure 10 As shown, the second beam expander 62 can also be configured in the same manner as the first beam expander 61 described above. For example, the second beam expander 62 can be configured to include a diverging unit formed by a first convex lens and a collimating unit formed by a second convex lens. Alternatively, in this embodiment of the invention, the second beam expander 62 can also be configured with other structures that can increase the width of the first polarized beam, and this embodiment of the invention is not limited thereto.

[0097] For example, the first dimming component 31 includes a prism, and the first portion 5 includes air. The prism arrangement allows for the separation of the first polarized light and the second polarized light emitted from the backlight assembly, resulting in high polarization, similar energy levels, and minimal energy loss, thereby achieving efficient utilization of the light source, reducing power consumption and heat generation. For example, the prism includes a right-angle prism.

[0098] Optionally, in embodiments of the present invention, a first optical path adjustment component may also be provided on the side of the first dimming component 31 away from the birefringent component 21. In the configuration such... Figure 8 and Figure 9 In the first beam expander 61 shown, exemplarily, in this embodiment of the invention, the first optical path adjustment component can be disposed between the first dimming component 31 and the first beam expander 61. That is, the first polarized beam emitted from the third surface 313 of the first dimming component 31 first passes through the first optical path adjustment component to adjust its propagation direction and then passes through the first beam expander 61 to increase its width. Alternatively, in this embodiment of the invention, the first optical path adjustment component can also be disposed on the side of the first beam expander 61 away from the first dimming component 31. That is, the first polarized beam emitted from the third surface 313 of the first dimming component 31 first passes through the first beam expander 61 to increase its width and then passes through the first optical path adjustment component to adjust its propagation direction. When setting such... Figure 10In the second beam expander 62 shown, exemplarily, in this embodiment of the invention, the first optical path adjustment component can be disposed between the first dimming component 31 and the second beam expander 62. That is, the first polarized beam emitted from the second surface 312 of the first dimming component 31 first passes through the first optical path adjustment component to adjust its propagation direction and then passes through the second beam expander 62 to increase its width. Alternatively, the first optical path adjustment component can be disposed on the side of the second beam expander 62 away from the first dimming component 31. That is, the first polarized beam emitted from the second surface 312 of the first dimming component 31 first passes through the second beam expander 62 to increase its width and then passes through the first optical path adjustment component to adjust its propagation direction. Figure 11 As shown, Figure 11 This is a cross-sectional schematic diagram of another backlight assembly provided in an embodiment of the present invention, wherein the first optical path adjustment component 33 is disposed on the side of the second beam expander 62 away from the first dimming component 31. The first optical path adjustment component 33 allows adjustment of the propagation direction of the first polarized light emitted from the first dimming component 31 along the first direction h1, making the output direction of the first polarized beam controllable to meet different application requirements. Optionally, the first optical path adjustment component 33 may include a reflector or a coated high-transparency prism, or any other component capable of changing the direction of light propagation.

[0099] For example, in embodiments of the present invention, a first width adjustment component may be provided on the side of the first beam expander 61 or the second beam expander 62 away from the first dimming component 31. The first width adjustment component receives the first polarized beam emitted from the first beam expander 61 or the second beam expander 62 and further adjusts the width of the first polarized beam emitted from the first beam expander 61 or the second beam expander 62 to make the light-emitting area of ​​the first polarized beam controllable, thereby meeting different application requirements. Optionally, the first width adjustment component includes an optical system or optical component capable of increasing or decreasing the beam width. For example, the first width adjustment component can be implemented by an optical component such as a lens system or a coated high-transparency prism. Figure 11 The diagram illustrates the use of a first width adjustment component 34 receiving first polarized light emitted sequentially from a first dimming component 31, a second beam expander 62, and a first optical path adjustment component 33. It should be noted that... Figure 11 The illustration of the first width adjustment component 34 receiving light rays emitted sequentially from the second beam expander 62 and the first optical path adjustment component 33 is merely a schematic diagram. In this embodiment of the invention, the first polarized beam emitted from the second beam expander 62 can also be directed to the first width adjustment component 34 first to change the output width, and then directed to the first optical path adjustment component 33 to change the propagation direction.

[0100] For example, such as Figure 8 , Figure 9 , Figure 10 and Figure 11As shown, when the first direction h1 intersects with the aforementioned preset direction h0, the embodiment of the present invention can make the second direction h2 parallel to the preset direction h0.

[0101] For example, such as Figure 8 and Figure 9 As shown, the first beam expander 61 is located in the optical path of the first polarized light emitted from the first dimming component 31, preventing the first beam expander 61 from receiving the second polarized light emitted from the birefringent component 21. Figure 10 and Figure 11 As shown, the second beam expander 62 is located in the optical path of the first polarized light emitted from the first dimming component 31, so as to prevent the second beam expander 62 from receiving the second polarized light emitted from the birefringent component 21.

[0102] Optional, such as Figure 8 , Figure 9 , Figure 10 and Figure 11 As shown, the backlight assembly also includes a third beam expander 63, which is located on the optical path of the second polarized light emitted from the birefringent component 21. The third beam expander 63 is used to expand the second polarized beam emitted from the birefringent component 21. When there is a gap G3 between the light emanating from the birefringent component 21 and propagating along the second direction h2, this embodiment of the invention can increase the width of the second polarized beam by providing the third beam expander 63, such as... Figure 8 , Figure 9 , Figure 10 and Figure 11 As shown, the extension line of a portion of the light emitted from the third beam expander 63 can pass through the gap G3 between two adjacent second polarized beams, which helps to make the second polarized light emitted from the backlight assembly more uniform. Moreover, in this embodiment of the invention, the third beam expander 63 is positioned in the optical path of the second polarized light emitted from the birefringent component 21, thus preventing the third beam expander 63 from receiving the first polarized light emitted from the first dimming component 31.

[0103] For example, such as Figure 8 , Figure 9 , Figure 10 and Figure 11 As shown, the third beam expander 63 can also be configured in the same manner as the first beam expander 61 described above. For example, the third beam expander 63 can be configured to include a diverging unit formed by a first convex lens and a collimating unit formed by a second convex lens. Alternatively, the third beam expander 63 can be configured with other structures that can increase the width of the second polarized beam, and this embodiment of the invention does not limit this.

[0104] Optional, such as Figure 11As shown, in this embodiment of the invention, a second optical path adjustment component 32 can also be provided in the backlight assembly. The second optical path adjustment component 32 is located on the optical path of the second polarized light emitted from the birefringent component 21, and is used to adjust the propagation direction of the second polarized beam emitted from the birefringent component 21. When providing the second optical path adjustment component 32, this embodiment of the invention positions the second optical path adjustment component 32 on the optical path of the second polarized light emitted from the birefringent component 21 to prevent the second optical path adjustment component 32 from receiving the first polarized light emitted from the first dimming component 31. It should be noted that when the third beam expander 63 and the second optical path adjustment component 32 are provided simultaneously, Figure 11 The second optical path adjustment component 32 shown is located on the optical path of the second polarized light emitted from the third beam expander 63 for illustration only. In this embodiment of the invention, the third beam expander 63 can also be located on the optical path of the second polarized light emitted from the second optical path adjustment component 32. That is, the second polarized light emitted from the birefringent component 21 is first passed through the second optical path adjustment component 32 to change its propagation direction, and then passed through the third beam expander 63 for beam expansion.

[0105] Similar to the setting of the first width adjustment component 34, such as Figure 11 As shown, in this embodiment of the invention, a second width adjustment component 35 can be provided to further adjust the width of the second polarized beam emitted from the third beam expander 63, so that the output area of ​​the second polarized beam is controllable to meet different application requirements. Optionally, the second width adjustment component 35 includes an optical system or optical component capable of increasing or decreasing the beam width. For example, the second width adjustment component 35 can be implemented by an optical component such as a lens system or a coated high-transparency prism.

[0106] It should be noted that, Figure 11 The illustration of the second width adjustment component 35 receiving light rays emitted sequentially from the third beam expander 63 and the second optical path adjustment component 32 is merely schematic. In this embodiment of the invention, the second polarized beam emitted from the third beam expander 63 can also be directed to the second width adjustment component 35 first to change the output width, and then directed to the second optical path adjustment component 32 to change the propagation direction.

[0107] See you again Figure 4 When the first distance t1 between the first boundary of the incident surface 311 of the first dimming component 31 and the second effective area B1 is greater than 0, in addition to designing the cross-sectional shape of the first dimming component 31 on the first cross-section as a right triangle, the embodiments of the present invention can also... Figure 4 The portion of the first dimming component 31 corresponding to the distance t1 shown is removed; that is, the cross-sectional shape of the first dimming component 31 on the first section is designed as follows. Figure 12 The right trapezoid shown Figure 12This is a schematic diagram of another backlight assembly provided in an embodiment of the present invention, wherein a triangular pattern with a dashed outline illustrates... Figure 4 The portion of the first dimming component 31 shown corresponds to the distance t1. Alternatively, in embodiments of the present invention, without affecting the light emitted from the adjacent first dimming component 31, the portion corresponding to the distance t1 is also shown. Figure 4 The portion of the first dimming component 31 shown that corresponds to the distance t1 is set to a different shape.

[0108] Optional, such as Figure 13 As shown, Figure 13 This is a schematic diagram of a first dimming component and a connecting portion provided in an embodiment of the present invention. The backlight assembly further includes a connecting portion 30, which is used to connect two adjacent first dimming components. Figure 13 Using three first dimming components as an example, these three first dimming components are labeled 31_1, 31_2, and 31_3, respectively. Exemplarily, the connecting portion 30 and the first dimming components 31 can be integrally formed. The provision of the connecting portion 30 can improve the overall strength of the plurality of first dimming components 31, thereby preventing deformation of the entire assembly comprising the plurality of first dimming components 31.

[0109] For example, the birefringent component 21 described above includes a birefringent crystal or a liquid crystal layer. Optionally, the liquid crystal layer includes an electro-controlled liquid crystal layer.

[0110] This invention also provides a head-up display (HUD) system, such as... Figure 14 As shown, Figure 14 This is a schematic diagram of a head-up display system provided in an embodiment of the present invention. The head-up display system includes the backlight assembly 100, a first image source 71, and a second image source 72. The backlight assembly 100 emits a first backlight beam and a second backlight beam. The polarization directions of the light rays in the first backlight beam and the second backlight beam are perpendicular to each other. One of the first backlight beam and the second backlight beam corresponds to the first polarized light, and the other corresponds to the second polarized light. For example, the first backlight beam can correspond to the first polarized light, and the second backlight beam can correspond to the second polarized light. Alternatively, in this embodiment of the present invention, the first backlight beam can correspond to the second polarized light, and the second backlight beam can correspond to the first polarized light.

[0111] The first image source 71 is located in the optical path of the first backlight beam emitted by the backlight assembly 100, and is used to receive the first backlight beam emitted by the backlight assembly 100 and emit a first display light corresponding to the displayed information; the second image source 72 is located in the optical path of the second backlight beam emitted by the backlight assembly 100, and is used to receive the second backlight beam emitted by the backlight assembly 100 and emit a second display light corresponding to the displayed information. For example, the displayed information includes the vehicle's current speed or navigation information.

[0112] like Figure 14 As shown, the head-up display system also includes an optical element 8, located in the optical path of the first display light and the second display light, for receiving and reflecting the first display light to form a first virtual image 81, and receiving and reflecting the second display light to form a second virtual image 82. Optionally, the optical element 8 includes a reflective-transmitting element that can both transmit and reflect light. Reflective-transmitting elements include those used in automotive windshields. Figure 14 As shown, the first and second display rays, after being reflected by optical element 8, can enter the eye box 83. When the driver's eyes are within the eye box, they can observe the first virtual image 81 and the second virtual image 82, allowing the driver to see information such as vehicle speed and navigation directly by looking at the windshield without turning or looking down at the instrument panel. Since optical element 8 can also transmit ambient light, the user can see the first virtual image 81 and the second virtual image 82 and the augmented reality effect superimposed by ambient light through optical element 8. For example, as... Figure 14 As shown, the first virtual image 81 and the second virtual image 82 have different imaging distances. Optionally, the first virtual image 81, which has a relatively shorter imaging distance, can display vehicle speed information, while the second virtual image 82, which has a relatively longer imaging distance, can display navigation information.

[0113] The head-up display system provided in this embodiment of the invention, based on the aforementioned backlight assembly 100, allows the backlight assembly 100 to provide the backlight required for operation to the first image source 71 and the second image source 72 respectively. The first image source 71 uses the first backlight beam to emit a first display light for presenting a first virtual image, and the second image source 72 uses the second backlight beam to emit a second display light for presenting a second virtual image. The system can simultaneously utilize the first and second backlight beams that meet the requirements of two sets of optical path light sources for AR HUD, eliminating the need to set up two sets of backlight assemblies to provide the backlight required for operation of the first image source 71 and the second image source 72 respectively. This reduces power consumption and heat generation.

[0114] For example, such as Figure 14 As shown, the first image source 71 and the second image source 72 include a liquid crystal display screen 70. The liquid crystal display screen 70 includes a liquid crystal layer 701 and a first polarizer 702. The first polarizer 702 is located on the side of the liquid crystal layer 701 away from the backlight assembly 100.

[0115] Optionally, in this embodiment of the invention, a second polarizer may be disposed between the liquid crystal layer 701 and the backlight assembly 100, wherein the transmission axis direction of the second polarizer corresponding to the first image source 71 is parallel to the polarization direction of the light in the first backlight beam received by the first image source 71, and the transmission axis direction of the second polarizer corresponding to the second image source 72 is parallel to the polarization direction of the light in the second backlight beam received by the second image source 72; or, in this embodiment of the invention, the second polarizer may not be disposed between the liquid crystal layer 701 and the backlight assembly 100. Figure 14 The illustration shows that no second polarizer is provided between the liquid crystal layer 701 corresponding to the first image source 71 and the second image source 72 and the backlight assembly 100. Based on the arrangement provided in this embodiment, the light rays in the first backlight beam emitted by the backlight assembly 100 and directed towards the first image source 71 and the second backlight beam directed towards the second image source 72 have polarization characteristics. Therefore, it is unnecessary to provide a second polarizer for polarization between the liquid crystal layer 701 and the backlight assembly 100. Only a first polarizer 702 for polarization detection needs to be provided on the side of the liquid crystal layer 701 away from the backlight assembly 100. The first polarizer 702 is used to analyze the polarized light modulated by the liquid crystal layer 701, generating gray levels corresponding to different pixels, thereby producing a display image. Based on this arrangement, both the first and second backlight beams emitted by the backlight assembly 100 can be efficiently utilized, avoiding the light energy loss problem caused by providing a polarizer for polarization.

[0116] For example, the transmission axis of the first polarizer 702 in the first image source 71 is perpendicular to the polarization direction of the light in the first back beam. The transmission axis of the first polarizer 702 in the second image source 72 is perpendicular to the polarization direction of the light in the second back beam.

[0117] When the second back beam received by the second image source 72 includes polarized light as S-beam, optionally, such as Figure 14As shown, the second image source 72 also includes a first half-wave plate 721. In the second image source 72, the first half-wave plate 721 is located on the side of the first polarizer 702 away from the liquid crystal layer 701. The arrangement of the first half-wave plate 721 can adjust the vibration direction of the light emitted from the first polarizer 702 of the second image source 72, so that the light incident on the optical element 8 is adjusted to S-beam. Alternatively, in another feasible embodiment, the present invention can also provide a second half-wave plate in the second image source 72 located on the side of the liquid crystal layer 701 close to the backlight assembly 100. The arrangement of the second half-wave plate can adjust the vibration direction of the light in the second backlight beam received by the second image source 72, so that the light emitted from the first polarizer 702 of the second image source 72 is adjusted to S-beam. The reflectivity of S-beam is higher than that of P-beam. Therefore, by providing the first half-wave plate 721 or the second half-wave plate, the present invention can improve the reflectivity of the optical element 8, thereby increasing the intensity of the light entering the eye box 83. When a second half-wave plate is provided on the side of the liquid crystal layer 701 near the backlight assembly 100, the transmission axis direction of the first polarizer 702 is parallel to the polarization direction of the S-light.

[0118] It should be noted that the above description only illustrates the method of setting a first half-wave plate 721 or a second half-wave plate in the second image source 72, taking the example that the second back beam received by the second image source 72 includes polarized light as S-ray. Of course, when the first back beam received by the first image source 71 includes polarized light as S-ray, the embodiments of the present invention can also set a first half-wave plate in the first image source 71 on the side of the first polarizer 702 away from the liquid crystal layer 701, so as to adjust the vibration direction of the light emitted from the first polarizer 702 of the first image source 71, so that the light emitted by the first image source 71 and directed towards the optical element 8 is adjusted to S-ray. Similarly, the embodiments of the present invention can also set a second half-wave plate in the first image source 71 on the side of the liquid crystal layer 701 closer to the backlight assembly 100. The setting of the second half-wave plate can adjust the vibration direction of the light in the first back beam received by the first image source 71, so that the light emitted by the first polarizer 702 of the first image source 71 is adjusted to S-ray. The arrangement of the first half-wave plate or the second half-wave plate in the first image source 71 is beneficial to improving the reflectivity of the optical element 8, thereby increasing the intensity of the light entering the eye box 83. When the second half-wave plate is arranged on the side of the liquid crystal layer 701 near the backlight assembly 100 corresponding to the first image source 71, the transmission axis direction of the first polarizer 702 in the first image source 71 is parallel to the polarization direction of the S-light.

[0119] For example, such as Figure 14As shown, the head-up display system also includes multiple reflective components 9, which are used to reflect the first display light to the optical element 8 and to reflect the second display light to the optical element 8. Based on the configuration provided by the embodiments of the present invention, the first backlight beam and the second backlight beam emitted by the backlight assembly 100 can share a single reflection system including the reflective components 9, which helps to simplify the structure of the head-up display system.

[0120] In one feasible way, such as Figure 14 As shown, when the angle between the light propagation direction of the first back beam received by the first image source 71 and the light propagation direction of the second back beam received by the second image source 72 is large, the embodiment of the present invention can configure the reflecting component 9 to include a first reflecting mirror 91 and a second reflecting mirror 92. For example... Figure 14 As shown, the first reflector 91 is used to receive the first display light emitted by the first image source 71 and reflect the first display light to the optical element 8. The second reflector 92 is used to receive the second display light emitted by the second image source 72 and reflect the second display light back to the first reflector 91, and the second display light is reflected by the first reflector 91 to the optical element 8.

[0121] In another possible way, such as Figure 15 As shown, Figure 15 This is a schematic diagram of another head-up display system provided in an embodiment of the present invention. When the angle between the light propagation direction of the first backlight beam received by the first image source 71 and the light propagation direction of the second backlight beam received by the second image source 72 is small, the reflective component 9 in this embodiment of the present invention can be configured to include a first reflector 91, a second reflector 92, and a third reflector 93. Combined with... Figure 15 As shown, the third reflector 93 receives the first display light emitted from the first image source 71 and reflects it to the second reflector 92. The second reflector 92 reflects the received first display light so that the reflected light is directed towards the first reflector 91. The first reflector 91 then reflects the received first display light to the optical element 8. The second reflector 92 can also receive the second display light emitted from the second image source 72 and reflect it to the first reflector 91. The first reflector 91 then reflects the received second display light to the optical element 8.

[0122] The above description, based on the embodiments shown in the figures, details the structure, features, and effects of the present invention. The above description is only a preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown in the figures. Any changes made in accordance with the concept of the present invention, or equivalent embodiments modified to have equivalent changes, that do not exceed the spirit covered by the specification and figures, should be within the protection scope of the present invention.

Claims

1. A backlight assembly, characterized in that, include: A light source, used to emit light; A birefringent component, located on one side of the light source, is used to split the light incident on the birefringent component into a first polarized light and a second polarized light, wherein the vibration direction of the first polarized light is perpendicular to the vibration direction of the second polarized light. The birefringent component includes a first region and a second region, wherein the first polarized light corresponds to the first region and the second polarized light corresponds to the second region, and the first region and the second region do not overlap at least partially in the direction of light emission. A first dimming component is located on the side of the birefringent component away from the light source; the first polarized light propagates along a first direction after being emitted from the first dimming component; the second polarized light propagates along a second direction, and the first direction intersects with the second direction; The birefringent component includes a first surface located on the side of the birefringent component closer to the light source, and the first surface includes a plurality of incident areas; The light emitted by the light source enters the birefringent component through the incident area. The backlight assembly includes a first cross section, which is parallel to both the optical axis of the birefringent component and the normal to the incident surface of the birefringent component. The length of the incident region on the first cross section is d21, and the length of the interval between two adjacent incident regions on the first cross section is d22; the length of the birefringent component in the direction perpendicular to the first surface is T; the angle between the propagation directions of the first polarized light and the second polarized light in the birefringent component is β; Where 0 < d21 ≤ Ttanβ ≤ d22.

2. The backlight assembly according to claim 1, characterized in that, The first region and the second region do not overlap in the direction of light emission; The length of the first region on the first cross-section is d11, and the length of the second region on the first cross-section is d12. d11=d12.

3. The backlight assembly according to claim 1, characterized in that, The backlight assembly further includes a second dimming component located between the light source and the birefringent component, the second dimming component being used to adjust the light incident on the birefringent component to include a plurality of incident beams corresponding to the incident area.

4. The backlight assembly according to claim 3, characterized in that, The second dimming component includes multiple microlens groups, each microlens group including a convex lens and a concave lens, wherein the convex lens is located on the side of the concave lens away from the birefringent component; the concave lens is disposed corresponding to the incident area; The concave lens includes a first effective region with a width of d31 on the first cross section, and the convex lens has a width of d41 on the first cross section, with the width direction perpendicular to the light propagation direction of the incident light. The distance between two adjacent first effective regions is d32, and two adjacent convex lenses are in contact. Wherein, d41 > d31 = d21; d32 = d22.

5. The backlight assembly according to claim 1, characterized in that, The length of the incident surface of the first dimming component on the first cross section is a, and the distance between two adjacent first dimming components is c, where a≥d11>0 and c≥d12>0.

6. The backlight assembly according to claim 5, characterized in that, The first dimming component includes a second surface and a third surface perpendicular to the first cross-section, both the second surface and the third surface being located on the side of the incident surface away from the birefringent component; The second surface and the incident surface have an included angle θ1, where 0 < θ1 < 90°, and the third surface is perpendicular to the incident surface.

7. The backlight assembly according to claim 6, characterized in that, The backlight assembly further includes a first portion, a portion of which is located on the side of the second surface away from the first dimming component, and another portion of which is located on the side of the third surface away from the first dimming component. The first portion is in contact with both the second surface and the third surface. The refractive index of the first dimming component is n1, and the refractive index of the first part is n2, where n2 < n1.

8. The backlight assembly according to claim 7, characterized in that, 。 9. The backlight assembly according to claim 6, characterized in that, The backlight assembly includes a first cross section, which is parallel to both the optical axis of the birefringent component and the normal to the incident surface of the birefringent component. The length of the incident surface of the first dimming component on the first cross section is a, and the length of the third surface on the first cross section is b; a < b.

10. The backlight assembly according to claim 9, characterized in that, ,in, c is the distance between two adjacent first dimming components, the incident surface of the first dimming component includes a second effective area, and t1 is the distance between the first boundary of the incident surface and the second effective area.

11. The backlight assembly according to claim 10, characterized in that, ； The backlight assembly further includes a first beam expander, which is used to expand the first polarized beam emitted through the third surface.

12. The backlight assembly according to claim 11, characterized in that, The backlight assembly further includes a first width adjustment component, which is used to adjust the width of the first polarized beam emitted sequentially through the third surface and the first beam expander; or, The first width adjustment component is used to adjust the width of the first polarized beam that exits only through the third surface.

13. The backlight assembly according to claim 7, characterized in that, 。 14. The backlight assembly according to claim 13, characterized in that, 。 15. The backlight assembly according to claim 13, characterized in that, The backlight assembly further includes a second beam expander, which is used to expand the first polarized beam emitted through the second surface.

16. The backlight assembly according to claim 15, characterized in that, The backlight assembly further includes a first width adjustment component, which is used to adjust the width of the first polarized beam emitted sequentially through the second surface and the second beam expander.

17. The backlight assembly according to claim 7, characterized in that, The first dimming component includes a prism, and the first portion includes air.

18. The backlight assembly according to claim 1, characterized in that, The backlight assembly further includes a first connecting portion, which is used to connect two adjacent first dimming components.

19. The backlight assembly according to claim 1, characterized in that, The backlight assembly further includes a first optical path adjustment component, which is used to adjust the propagation direction of the first polarized beam emitted through the first dimming component.

20. The backlight assembly according to claim 1, characterized in that, The backlight assembly further includes a second optical path adjustment component, which is used to adjust the propagation direction of the second polarized light emitted from the birefringent component.

21. The backlight assembly according to claim 1, characterized in that, The backlight assembly also includes a third beam expander, which is used to expand the second polarized beam emitted from the birefringent component.

22. The backlight assembly according to claim 21, characterized in that, The backlight assembly further includes a second width adjustment component, which is used to adjust the width of the second polarized beam emitted through the third beam expander.

23. The backlight assembly according to claim 1, characterized in that, The birefringent component includes a birefringent crystal or a liquid crystal layer.

24. A head-up display system, characterized in that, include: Backlight assembly, the backlight assembly comprising: A light source, used to emit light; A birefringent component, located on one side of the light source, is used to split the light incident on the birefringent component into a first polarized light and a second polarized light, wherein the vibration direction of the first polarized light is perpendicular to the vibration direction of the second polarized light. The birefringent component includes a first region and a second region, wherein the first polarized light corresponds to the first region and the second polarized light corresponds to the second region, and the first region and the second region do not overlap at least partially in the direction of light emission. A first dimming component is located on the side of the birefringent component away from the light source; the first polarized light propagates along a first direction after being emitted from the first dimming component; the second polarized light propagates along a second direction, and the first direction intersects with the second direction; The backlight assembly is used to emit a first backlight beam and a second backlight beam. The polarization directions of the light in the first backlight beam and the second backlight beam are perpendicular to each other. One of the first backlight beam and the second backlight beam corresponds to the first polarized light, and the other corresponds to the second polarized light. A first image source is used to receive the first back beam and emit a first display light; The second image source is used to receive the second back beam and emit the second display light; An optical element for receiving and reflecting the first display light to form a first virtual image, and for receiving and reflecting the second display light to form a second virtual image.

25. A head-up display system, characterized in that, include: The backlight assembly according to any one of claims 1-23, wherein the backlight assembly is used to emit a first backlight beam and a second backlight beam, the polarization directions of the light in the first backlight beam and the second backlight beam are perpendicular to each other, one of the first backlight beam and the second backlight beam corresponds to the first polarized light, and the other corresponds to the second polarized light. A first image source is used to receive the first back beam and emit a first display light; The second image source is used to receive the second back beam and emit the second display light; An optical element for receiving and reflecting the first display light to form a first virtual image, and for receiving and reflecting the second display light to form a second virtual image.

26. The head-up display system according to claim 24 or 25, characterized in that, The first image source and the second image source include a liquid crystal display screen, the liquid crystal display screen includes a liquid crystal layer and a first polarizer, the first polarizer is located on the side of the liquid crystal layer away from the backlight assembly, a second polarizer is included between the liquid crystal layer and the backlight assembly, or, no second polarizer is provided between the liquid crystal layer and the backlight assembly.

27. The head-up display system according to claim 26, characterized in that, The second image source includes a first half-wave plate, which is located on the side of the first polarizer away from the liquid crystal layer; or, The second image source includes a second half-wave plate, which is located on the side of the liquid crystal layer near the backlight assembly.

28. The head-up display system according to claim 24 or 25, characterized in that, It also includes multiple reflective components for reflecting the first display light to the optical element and reflecting the second display light to the optical element.

Images