Optical system and display device

Abstract

An optical system and a display device. The optical system comprises a prism group. Different color image lights are emitted from a same light exit surface after converging in the prism group. The prism group comprises first light adjusting structures and second light adjusting structures arranged between prisms. Different color image lights comprise first color image light and second color image light. The first light adjusting structures are configured to change the propagation direction of the first color image light, and at least another color image light. The second light adjusting structures are configured to change the propagation direction of the second color image light, and transmit the at least another color image light. The first light adjusting structures and the second light adjusting structures each comprise a multilayer film layer. At least one of the first light adjusting structures and the second light adjusting structures comprises a columnar layer. The columnar layer comprises a plurality of columnar structures, and the columnar structures in at least a partial region are closely arranged. The columnar layer is arranged to reduce the number of film layers in the light adjusting structure, and improve the brightness of the emitted light.

Description

Technical Field

[0001] Embodiments of this disclosure relate to an optical system and a display device. Background Technology

[0002] In near-eye display devices, such as augmented reality (AR) display devices, a complete and realistic virtual image can be generated by precisely combining red, green, and blue image light. During the light combining process, the accuracy of the brightness and direction of each color image light directly determines the realism and consistency of the image. Only by precisely controlling the brightness and direction of each color image light can color shifts or overly bright or dark areas be avoided, thus ensuring that the final displayed image has uniform color and a stable picture. Summary of the Invention

[0003] At least one embodiment of this disclosure provides an optical system and a display device.

[0004] At least one embodiment of this disclosure provides an optical system including a prism assembly. The prism assembly includes a plurality of incident light surfaces and an exit light surface, each incident light surface being configured to incident a color image light, different incident light surfaces being configured to incident different color image lights, and the different color image lights converging in the prism assembly and exiting from the one exit light surface. The prism assembly includes multiple prisms, with a first light adjustment structure and a second light adjustment structure sandwiched between the multiple prisms. The different color image light includes at least a first color image light and a second color image light. The first light adjustment structure is configured to change the propagation direction of the first color image light and transmit at least one other color image light besides the first color image light. The second light adjustment structure is configured to change the propagation direction of the second color image light and transmit at least one other color image light besides the second color image light. Both the first light adjustment structure and the second light adjustment structure include multiple layers of film stacked together. At least one of the first light adjustment structure and the second light adjustment structure includes at least one columnar layer. Each columnar layer includes multiple columnar structures, and the columnar structures in at least a portion of the same columnar layer are closely arranged.

[0005] For example, according to an embodiment of this disclosure, in the same light adjustment structure of the first light adjustment structure and the second light adjustment structure, the multilayer film includes a first film and a second film alternately disposed in a direction perpendicular to the prism surface where the multilayer film is located, the refractive index of the first film is greater than the refractive index of the second film, and at least one of the first film and the second film is a columnar layer in the at least one columnar layer.

[0006] For example, according to an embodiment of this disclosure, both the first film layer and the second film layer are columnar layers, and the height of the columnar structure in the first film layer is equal to the height of the columnar structure in the second film layer.

[0007] For example, according to an embodiment of this disclosure, the maximum size of the columnar structure in the first film layer cut by a plane perpendicular to its extension direction is a first size, and the maximum size of the columnar structure in the second film layer cut by a plane perpendicular to its extension direction is a second size, wherein the first size is larger than the second size.

[0008] For example, according to an embodiment of this disclosure, the prism group includes a first prism surface with the first light adjustment structure and a second prism surface with the second light adjustment structure. The first prism surface intersects with the second prism surface. Both the first light adjustment structure and the second light adjustment structure include a columnar layer in the at least one columnar layer. In the first light adjustment structure and the second light adjustment structure, the columnar structures in at least a portion of the region are inclined. The angle between the extension direction of the inclined columnar structure and the normal of the prism surface is 15 to 30 degrees. The inclination angle of the columnar structure in the first light adjustment structure is different from that in the second light adjustment structure.

[0009] For example, according to an embodiment of this disclosure, the plurality of light-incident surfaces include a first light-incident surface, a second light-incident surface, and a third light-incident surface. The first light-incident surface and the second light-incident surface are disposed opposite to each other, and the third light-incident surface is disposed opposite to the light-outcident surface. One of the first color image light and the second color image light is incident into the prism group from the first light-incident surface, and the other of the first color image light and the second color image light is incident into the prism group from the second light-incident surface. At least one of the first prism surface and the second prism surface includes a first distribution area, a second distribution area, and a third distribution area arranged sequentially. The first distribution area... The first, second, and third distribution areas are projected onto the light-emitting surface as a first area, a second area, and a third area, respectively, arranged sequentially along the arrangement direction of the first and second light-emitting surfaces. Along the arrangement direction, the size ratio of the first area, the second area, and the third area is 1:8:1. The columnar structures located at least in the first and third distribution areas are inclined, with the columnar structures in the first distribution area inclined towards the second distribution area, and the columnar structures in the third distribution area inclined towards the second distribution area.

[0010] For example, according to an embodiment of this disclosure, the maximum size of the cross-section of the columnar structure in the first light adjustment structure cut by a plane perpendicular to its extension direction is different from the maximum size of the cross-section of the columnar structure in the second light adjustment structure cut by a plane perpendicular to its extension direction, and the height of the columnar structure in the first light adjustment structure is different from the height of the columnar structure in the second light adjustment structure.

[0011] For example, according to an embodiment of this disclosure, the first color image light is red image light, and the second color image light is blue image light; the different color image light further includes a third color image light, the third color image light is green image light, and the third color image light is incident on the prism group from the third light-incident surface; the first light adjustment structure is configured to transmit the second color image light and the third color image light, and the second light adjustment structure is configured to transmit the first color image light and the third color image light.

[0012] For example, according to an embodiment of this disclosure, the red image light has a first wavelength, and the blue image light has a second wavelength; in the first light adjustment structure, the maximum size of the cross-section of the columnar structure cut by a plane perpendicular to its extension direction is 100-200 nanometers, and the thickness of each film layer in the first light adjustment structure is one-quarter of the first wavelength; in the second light adjustment structure, the maximum size of the cross-section of the columnar structure cut by a plane perpendicular to its extension direction is 50-100 nanometers, and the thickness of each film layer in the second light adjustment structure is one-quarter of the second wavelength.

[0013] For example, according to an embodiment of this disclosure, the angle between the columnar structure in the first light adjustment structure and the normal of the first prism surface is a first angle, and the angle between the columnar structure in the second light adjustment structure and the normal of the second prism surface is a second angle, wherein the first angle is greater than the second angle.

[0014] For example, according to an embodiment of this disclosure, the first included angle is 15 to 25 degrees, and the second included angle is 20 to 30 degrees.

[0015] For example, according to an embodiment of this disclosure, the third light-incident surface is provided with a third light-adjusting structure, which is configured to transmit the third color image light; the third light-adjusting structure includes one or more film layers, and the one or more film layers include the at least one columnar layer.

[0016] For example, according to an embodiment of this disclosure, in the third light adjustment structure, the columnar structures located in the same columnar layer are closely arranged, and the maximum size of the cross-section of the columnar structure by a plane perpendicular to its extension direction is 150 to 250 nanometers; the green image light has a third wavelength, and the thickness of each of the one or more film layers is one-quarter of the third wavelength.

[0017] For example, according to embodiments of this disclosure, in the first light adjustment structure and the second light adjustment structure, which include the at least one columnar layer, the number of the multilayer film layers is 2 to 100.

[0018] For example, according to an embodiment of this disclosure, the number of multilayer films is 40 to 60.

[0019] For example, according to an embodiment of this disclosure, in the third light adjustment structure, the number of one or more film layers is no more than 10.

[0020] For example, according to an embodiment of this disclosure, in the third light adjustment structure, the angle between the extending direction of the columnar structure and the normal of the third incident surface is no greater than 10 degrees.

[0021] Another embodiment of this disclosure provides a display device, including a plurality of display screens and any of the above-described optical systems, wherein the plurality of display screens are arranged in a one-to-one correspondence with the plurality of light incident surfaces, and different display screens emit image light of different colors. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this disclosure and are not intended to limit this disclosure.

[0023] Figure 1 This is a schematic diagram of a prism assembly that combines light from images of different colors.

[0024] Figure 2 for Figure 1 The diagram shows two prisms and a cross-sectional view of the first film layer group disposed on the two prisms.

[0025] Figure 3 for Figure 1 The diagram shows two other prisms and a cross-sectional view of the second film layer group disposed on these two prisms.

[0026] Figure 4 It shows Figure 1 The prism assembly shown illustrates the reflected light path of light rays incident at large angles.

[0027] Figure 5This is a schematic diagram of an optical system provided according to an example embodiment of the present disclosure.

[0028] Figure 6 for Figure 5 The diagram shows a first ray adjustment structure set on the first prism surface of the optical system in one example.

[0029] Figure 7 for Figure 5 The diagram shows a second ray adjustment structure set on the second prism surface in one example of the optical system shown.

[0030] Figure 8 for Figure 5 The optical system shown is illustrated in another example with a first prism surface having a first light adjustment structure.

[0031] Figure 9 for Figure 5 The diagram shows a first ray adjustment structure set on the first prism surface of the optical system in another example.

[0032] Figure 10 for Figure 5 The optical system shown is illustrated in another example with a second prism surface equipped with a second light adjustment structure.

[0033] Figure 11 This is a schematic diagram of an optical system provided according to another example of an embodiment of the present disclosure.

[0034] Figure 12 This is a partial structural schematic diagram of a display device according to another embodiment of the present disclosure. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Based on the described embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0036] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that an element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0037] Unless otherwise specified in the following embodiments of this disclosure, the quantity of a component is implied to mean that the component may be one or more, or can be understood as at least one. "At least one" means one or more, and "more" means at least two.

[0038] Figure 1 This is a schematic diagram of a prism assembly that combines light from images of different colors. Figure 2 for Figure 1 The diagram shows two prisms and a cross-sectional view of the first film layer group disposed on the two prisms. Figure 3 for Figure 1 The diagram shows two other prisms and a cross-sectional view of the second film layer group disposed on these two prisms.

[0039] like Figures 1 to 3 As shown, the prism assembly includes four prisms, such as prism 11, prism 12, prism 13 and prism 14; prism 11 includes a light-incident surface facing the red display screen 21, prism 12 includes a light-incident surface facing the green display screen 22, prism 13 includes a light-incident surface facing the blue display screen 23, and prism 14 includes a light-exit surface.

[0040] like Figures 1 to 3 As shown, in the prism group 10, a first film layer group 31 is provided on the prism surface 01 between prism 11 and prism 14 and between prism 12 and prism 13. The first film layer group 31 is used to reflect the blue image light emitted by the blue display screen 23 and transmit the green image light and red image light emitted by the other two display screens respectively. A second film layer group 32 is provided on the prism surface 02 between prism 11 and prism 12 and between prism 14 and prism 13. The second film layer group 32 is used to reflect the red image light emitted by the red display screen 21 and transmit the blue image light and green image light emitted by the other two display screens respectively. Finally, the red image light, green image light and blue image light converge at the light-emitting surface to form a combined light source, such as forming a complete color light source.

[0041] Figure 4 It shows Figure 1 The prism assembly shown illustrates the reflected light path of light rays incident at large angles.

[0042] During the research, the inventors of this application discovered that: Figure 4 As shown, prism arrays have the following problems, such as complex manufacturing, high cost, scattering loss and ghosting, and insufficient reflection efficiency.

[0043] For example, such as Figure 2 and Figure 3 As shown, the number of membrane layers in both the first membrane layer group 31 and the second membrane layer group 32 is greater than 150 layers. The large number of membrane layers increases the difficulty and cost of manufacturing.

[0044] For example, coating processes can cause light scattering and ghosting problems, which can easily reduce the contrast and sharpness of optical systems.

[0045] For example, such as Figure 4 As shown, when the angle between the light ray 41 incident on the film layer group on the prism surface 01 and the normal of the prism surface 01 is large, part of the light ray 41 is reflected towards the light-emitting surface by the film layer group, while the other part is transmitted by the film layer group. This results in the light ray 41 not being completely reflected towards the light-emitting surface. The reflection efficiency of the film layer group for the light ray 41 is lower than its reflectivity for the light ray perpendicularly emitted from the display screen 21, which easily affects the brightness and uniformity of the final displayed image. Similarly, the light ray 42 incident on the film layer group on the prism surface 02 will also exhibit a situation where part is reflected towards the light-emitting surface by the film layer group, while the other part is transmitted by the film layer group, thus affecting the brightness and uniformity of the final displayed image.

[0046] This disclosure provides an optical system and a display device. The optical system includes a prism assembly with multiple incident surfaces and an exiting surface. Each incident surface is configured to receive a color image light, and different incident surfaces are configured to receive different color image lights. The different color image lights converge in the prism assembly and exit from one exiting surface. The prism assembly includes multiple prisms, with a first light adjustment structure and a second light adjustment structure sandwiched between the multiple prisms. The different color image lights include at least a first color image light and a second color image light. The first light adjustment structure is configured to change the propagation direction of the first color image light and transmit at least one other color image light besides the first color image light. The second light adjustment structure is configured to change the propagation direction of the second color image light and transmit at least one other color image light besides the second color image light. Both the first and second light adjustment structures include stacked multilayer films. At least one of the first and second light adjustment structures includes at least one columnar layer. Each columnar layer includes multiple columnar structures, and the columnar structures in at least a portion of the same columnar layer are closely arranged.

[0047] By providing a columnar layer in at least one of the first light adjustment structure and the second light adjustment structure, it is beneficial to reduce the number of film layers in at least one of the first light adjustment structure and the second light adjustment structure, thereby reducing the loss caused by the film layers in changing the direction of light propagation of the corresponding color image, and improving the brightness and uniformity of the light emitted from the light-emitting surface.

[0048] The optical system and display device provided in the embodiments of this disclosure are described below with reference to the accompanying drawings.

[0049] Figure 5 This is a schematic diagram of an optical system provided according to an example embodiment of the present disclosure. Figure 6 for Figure 5The diagram shows a first ray adjustment structure set on the first prism surface of the optical system in one example. Figure 7 for Figure 5 The diagram shows a second ray adjustment structure set on the second prism surface in one example of the optical system shown.

[0050] like Figures 5 to 7 As shown, the optical system includes a prism group 100, which includes multiple incident surfaces and an exit surface 104. Each incident surface is configured to incident a color image light, and different incident surfaces are configured to incident different color image lights. The different color image lights converge in the prism group 100 and exit from the same exit surface 104.

[0051] like Figures 5 to 7 As shown, the prism assembly 100 includes multiple prisms, with a first light adjustment structure 200 and a second light adjustment structure 300 sandwiched between the multiple prisms. Different color image lights include at least a first color image light 501 and a second color image light 502. The first light adjustment structure 200 is configured to change the propagation direction of the first color image light 501 and transmit at least one other color image light besides the first color image light 501. The second light adjustment structure 300 is configured to change the second color image light 502 and transmit at least one other color image light besides the second color image light 502.

[0052] For example, such as Figure 5 As shown, the prism group 100 includes four prisms, such as the first prism 110, the second prism 120, the third prism 130 and the fourth prism 140. The prism group 100 can be approximately a cubic light combining prism group 100, and each prism is a right triangular prism.

[0053] For example, such as Figure 5 As shown, the first light adjustment structure 200 is sandwiched between the first prism 110 and the third prism 130, and between the second prism 120 and the fourth prism 140; the second light adjustment structure 300 is sandwiched between the first prism 110 and the fourth prism 140, and between the second prism 120 and the third prism 130.

[0054] Figure 5 The light adjustment structure located at the angle between the four prisms is schematically shown as the first light adjustment structure 200, but it is not limited to this. The light adjustment structure located at the angle between the four prisms can also be the second light adjustment structure 300, which can be set according to the requirements and process.

[0055] In some examples, such as Figure 5As shown, the plurality of light-incident surfaces include a first light-incident surface 101, a second light-incident surface 102, and a third light-incident surface 103. The first light-incident surface 101 and the second light-incident surface 102 are disposed opposite to each other, and the third light-incident surface 103 is disposed opposite to the light-outceasing surface 104. One of the first color image light 501 and the second color image light 502 is incident into the prism assembly 100 from the first light-incident surface 101, and the other of the first color image light 501 and the second color image light 502 is incident into the prism assembly 100 from the second light-incident surface 102. For example, the first light-incident surface 101 is configured to incident the first color image light 501, and the second light-incident surface 102 is configured to incident the second color image light 502.

[0056] In some examples, the different color image light also includes a third color image light 503, which is incident on the prism group 100 from the third incident surface 103.

[0057] For example, such as Figure 5 As shown, the first color image light 501, the second color image light 502, and the third color image light 503 converge in the prism group 100 and are emitted from the same light-emitting surface 104. The prism group 100 realizes the light combining effect of different color image lights.

[0058] In some examples, such as Figure 5 As shown, the first light adjustment structure 200 is configured to transmit the second color image light 502 and the third color image light 503, and the second light adjustment structure 300 is configured to transmit the first color image light 501 and the third color image light 503.

[0059] like Figures 5 to 7 As shown, both the first light adjustment structure 200 and the second light adjustment structure 300 include multilayered films stacked together. At least one of the first light adjustment structure 200 and the second light adjustment structure 300 includes at least one columnar layer. Each columnar layer includes multiple columnar structures, and the columnar structures within at least a portion of the same columnar layer are closely arranged. The term "region" can refer to a region defined in the plane containing the surface of each columnar layer closest to its prism surface. "Closely arranged" means that the edges of adjacent columnar structures are flush with each other without gaps.

[0060] By providing columnar layers in at least one of the first light adjustment structure 200 and the second light adjustment structure 300, it is beneficial to reduce the number of film layers in at least one of the first light adjustment structure 200 and the second light adjustment structure 300, thereby reducing the loss caused by the film layers in changing the direction of light propagation of the corresponding color image, and improving the brightness and uniformity of the light emitted from the light-emitting surface 104.

[0061] For example, such as Figure 6 and Figure 7As shown, the multiple columnar structures in the columnar layer have wavelength selectivity for the light incident on them. The multiple columnar structures are similar to gratings. For example, they can diffract light of a specific wavelength band, such as a specific color image light, to change the propagation direction of the specific color image light so that it propagates toward the light-emitting surface 104. At the same time, they can transmit other color image lights without changing their propagation direction, which is beneficial to improving the separation effect of different color image lights.

[0062] For example, such as Figure 6 As shown, the multilayer film 2000 of the first light adjustment structure 200 includes at least one columnar layer 210, and the columnar layer 210 includes a plurality of columnar structures 211, with the columnar structures 211 closely arranged in at least a portion of the region.

[0063] For example, such as Figure 7 As shown, the multilayer film 3000 of the second light adjustment structure 300 includes at least one columnar layer 310, and the columnar layer 310 includes a plurality of columnar structures 311, with the columnar structures 311 closely arranged in at least a portion of the region.

[0064] Figure 6 and Figure 7 The diagram schematically illustrates that both the first light adjustment structure 200 and the second light adjustment structure 300 include columnar layers. The columnar layer in the first light adjustment structure 200 diffracts the first color image light 501 to change the propagation direction of the first color image light 501, which is equivalent to reflecting the first color image light 501 to the light-emitting surface 104. The columnar layer in the second light adjustment structure 300 diffracts the second color image light 502 to change the propagation direction of the second color image light 502, which is equivalent to reflecting the second color image light 502 to the light-emitting surface 104. This achieves high reflection efficiency of both the first color image light 501 and the second color image light 502 in the optical system, thereby improving the output brightness of both the first color image light 501 and the second color image light 502.

[0065] Of course, the embodiments disclosed herein are not limited to this. In the optical system, only the first light adjustment structure 200 may include a columnar layer to make the efficiency of at least the first color image light 501 emitting to the light-emitting surface 104 higher. Alternatively, only the second light adjustment structure 300 may include a columnar layer to make the efficiency of at least the second color image light 502 emitting to the light-emitting surface 104 higher.

[0066] In some examples, such as Figure 5 As shown, in the first light adjustment structure 200 and the second light adjustment structure 300, the number of multilayer films in the structure including at least one columnar layer is 2 to 100.

[0067] Compared to Figures 1 to 4As shown, the number of film layers in both the first film layer group 31 and the second film layer group 32 is greater than that in the prism group 100 with 150 layers. In the optical system provided by this disclosure, by setting at least one of the first light adjustment structure 200 and the second light adjustment structure 300 to a structure including columnar layers, the number of film layers can be significantly reduced. This not only reduces the manufacturing difficulty and process cost, but also reduces the loss of light after passing through the film layers and improves the output brightness.

[0068] For example, Figure 6 and Figure 7 The first light adjustment structure 200 and the second light adjustment structure 300 are schematically shown to both include columnar layers, so that both the first light adjustment structure 200 and the second light adjustment structure 300 can improve the brightness and uniformity of the corresponding color image light, and improve the contrast and sharpness of the optical system.

[0069] For example, the number of multilayer films can be 5 to 20. For example, the number of multilayer films can be 10 to 15. For example, the number of multilayer films can be 30 to 90. For example, the number of multilayer films can be 50 to 80.

[0070] Figures 5 to 7 The overall structure of the multilayer film included in the first light adjustment structure 200 and the second light adjustment structure 300 is shown schematically. The number of layers shown is only schematic and does not represent the actual number of layers included in each structure.

[0071] In some examples, such as Figures 5 to 7 As shown, the number of the above-mentioned multilayer films is 40 to 60.

[0072] By setting the number of multilayer films to 40 to 60, it is beneficial to optimize the reflection efficiency of the first light adjustment structure 200 on the first color image light 501 and the reflection efficiency of the second light adjustment structure 300 on the second color image light 502.

[0073] In some examples, such as Figures 5 to 7 As shown, the prism assembly 100 includes a first prism surface 105 with a first light adjustment structure 200 and a second prism surface 106 with a second light adjustment structure 300. The first prism surface 105 and the second prism surface 106 intersect. Both the first light adjustment structure 200 and the second light adjustment structure 300 include at least one columnar layer.

[0074] For example, such as Figure 5 As shown, the first prism surface 105 and the second prism surface 106 can be prism surfaces located between the first light-incident surface 101 and the second light-incident surface 102, and the absolute values ​​of the included angles between the first prism surface 105 and the second prism surface 106 and the first light-incident surface 101 are the same, but the signs are opposite.

[0075] For example, such as Figure 5 As shown, the first prism surface 105 may include two opposing prism surfaces of the first prism 110 and the third prism 130, as well as two opposing prism surfaces of the second prism 120 and the fourth prism 140. For example, the second prism surface 106 may include two opposing prism surfaces of the first prism 110 and the fourth prism 140, as well as two opposing prism surfaces of the second prism 120 and the third prism 130.

[0076] For example, such as Figure 5 As shown, the columnar structure is formed on one of two opposing prism surfaces and is bonded to the other prism surface by an adhesive layer.

[0077] For example, such as Figure 6 As shown, in the first light adjustment structure 200, in the same columnar layer 210, the columnar structures 211 are arranged in an array along a direction parallel to the first prism surface 105. For example, in the same columnar layer 210, the shape of the orthographic projection of the columnar structure 211 on the first prism surface 105 can be circular, elliptical, or hexagonal, etc., and the orthographic projections of multiple columnar structures 211 are closely arranged. For example, the multilayer film layer 2000 includes at least two columnar layers 210, and the columnar structures 211 in different columnar layers 210 are arranged in a one-to-one correspondence. For example, the orthographic projections of the columnar structure 211 in one columnar layer 210 and the columnar structure 211 corresponding to it and located in another columnar layer 210 overlap on the first prism surface 105.

[0078] For example, such as Figure 7 As shown, in the second light adjustment structure 300, in the same columnar layer 310, the columnar structures 311 are arranged in an array along a direction parallel to the second prism surface 106. For example, in the same columnar layer 310, the shape of the orthographic projection of the columnar structure 311 on the second prism surface 106 can be circular, elliptical, or hexagonal, etc., and the orthographic projections of multiple columnar structures 311 are closely arranged. For example, the multilayer film layer 3000 includes at least two columnar layers 310, and the columnar structures 311 in different columnar layers 310 are arranged in a one-to-one correspondence. For example, the orthographic projections of the columnar structure 311 in one columnar layer 310 and the columnar structure 311 corresponding to it and located in another columnar layer 310 overlap on the second prism surface 106.

[0079] For example, such as Figure 6 As shown, in the first light adjustment structure 200, the extension direction of each columnar structure 211 in the same columnar layer 210 is parallel to the normal of the first prism surface 105. For example, the extension direction of the columnar structures 211 in different columnar layers 210 is the same.

[0080] For example, such as Figure 7As shown, in the second light adjustment structure 300, the extension direction of each columnar structure 311 in the same columnar layer 310 is parallel to the normal of the second prism surface 106. For example, the extension direction of the columnar structures 311 in different columnar layers 310 is the same.

[0081] In some examples, such as Figure 6 and Figure 7 As shown, the multilayer film includes a first film and a second film alternately arranged in a direction perpendicular to the prism surface where the multilayer film is located. The refractive index of the first film is greater than that of the second film, and at least one of the first film and the second film is a columnar layer.

[0082] By configuring the multilayer film to include alternating first and second layers with different refractive indices, and at least one layer to be a columnar layer, it is beneficial to optimize the interference effect of image light of a specific wavelength, thereby achieving an anti-reflection effect on image light of a specific wavelength. For example, the first color image light 501 incident on the first light adjustment structure 200 diffracts in the columnar layer and interferes in the multilayer film, thereby increasing the output light intensity of the first color image light 501 and improving optical purity. Similarly, the second color image light 502 incident on the second light adjustment structure 300 diffracts in the columnar layer and interferes in the multilayer film, thereby increasing the output light intensity of the second color image light 502 and improving optical purity.

[0083] For example, such as Figure 6 and Figure 7 As shown, the first film layer 201 is in contact with the first prism surface 105, and the first film layer 301 is in contact with the second prism surface 106.

[0084] In some examples, such as Figure 6 and Figure 7 As shown, both the first and second membrane layers are columnar layers, and the height of the columnar structure in the first membrane layer is equal to the height of the columnar structure in the second membrane layer.

[0085] The thickness of the first and second films in each light adjustment structure, i.e. the height of the columnar structure, must be related to the wavelength of the image light of a specific wavelength in order to achieve interference of the image light of a specific wavelength.

[0086] For example, such as Figure 6 As shown, in the first light adjustment structure 200, the first film layer 201 and the second film layer 202 are both columnar layers 210. The thickness of the columnar layer 210 is the height of the columnar structure 211. The height of the columnar structure 211 is related to the wavelength of the first color image light 501, such as being one-quarter of the wavelength of the first color image light 501.

[0087] For example, such as Figure 6As shown, in the first light adjustment structure 200, the maximum dimension of the cross-section of the columnar structure 211 in the first film layer 201 cut by a plane parallel to the first prism surface 105 is the first dimension, and the maximum dimension of the cross-section of the columnar structure 211 in the second film layer 202 cut by a plane parallel to the first prism surface 105 is the second dimension. The first dimension and the second dimension are the same. For example, when the cross-sectional shape of the columnar structure 211 in the first film layer 201 is circular, the first dimension is the diameter of the circle; when the cross-sectional shape of the columnar structure 211 in the first film layer 201 is elliptical, the first dimension is the length of the major axis of the ellipse; when the cross-sectional shape of the columnar structure 211 in the first film layer 201 is hexagonal, the first dimension is the length of the diagonal. Similarly, the columnar structure 211 in the second film layer 202 has the same cross-sectional shape and the same dimension as the columnar structure 211 in the first film layer 201.

[0088] For example, such as Figure 7 As shown, in the second light adjustment structure 300, the first film layer 301 and the second film layer 302 are both columnar layers 310. The thickness of the columnar layer 310 is the height of the columnar structure 311. The height of the columnar structure 311 is related to the wavelength of the second color image light 502, such as being one-quarter of the wavelength of the second color image light 502.

[0089] For example, such as Figure 7 As shown, in the second light adjustment structure 300, the maximum dimension of the cross-section of the columnar structure 311 in the first film layer 301 cut by a plane parallel to the second prism surface 106 is the first dimension, and the maximum dimension of the cross-section of the columnar structure 311 in the second film layer 302 cut by a plane parallel to the second prism surface 106 is the second dimension. The first dimension and the second dimension are the same. For example, when the cross-sectional shape of the columnar structure 311 in the first film layer 301 is circular, the first dimension is the diameter of the circle; when the cross-sectional shape of the columnar structure 311 in the first film layer 301 is elliptical, the first dimension is the length of the major axis of the ellipse; when the cross-sectional shape of the columnar structure 311 in the first film layer 301 is hexagonal, the first dimension is the length of the diagonal. Similarly, the columnar structure 311 in the second film layer 302 has the same cross-sectional shape and the same dimension as the columnar structure 211 in the first film layer 301.

[0090] Figure 6 and Figure 7 The diagram schematically illustrates that in the first light adjustment structure 200 and the second light adjustment structure 300, both the first film layer and the second film layer are columnar layers, but are not limited thereto. For example, in at least one of the first light adjustment structure 200 and the second light adjustment structure 300, one of the first film layer and the second film layer can be the aforementioned columnar layer, and the other is a non-columnar film layer. Figure 2 and Figure 3 The membrane layers in the membrane layer group shown are arranged alternately with other membrane layers, such as columnar layers.

[0091] For example, such as Figure 6 and Figure 7 As shown, the material of the first film layer may include at least one of silicon, silicon nitride (Si3N4), silicon carbide (SiC), zirconium dioxide (ZrO2), and tantalum pentoxide (Ta2O5), and the material of the second film layer may include at least one of optical polymer, fluoride, silicon dioxide (SiO2), titanium dioxide (TiO2), aluminum oxide (Al2O3), and indium tin oxide (ITO).

[0092] For example, the optical polymer may include polymethyl methacrylate (PMMA). For example, the material of the first film layer may include amorphous silicon, or monocrystalline silicon, polycrystalline silicon, etc. For example, fluorides may include magnesium fluoride (MgF2), aluminum fluoride (AlF3), etc.

[0093] Figure 8 for Figure 5 The optical system shown is illustrated in another example with a first prism surface having a first light adjustment structure.

[0094] In some examples, such as Figure 8 As shown, taking the first light adjustment structure 200 as an example, the maximum size of the columnar structure 211 in the first film layer 201 cut by a plane perpendicular to its extension direction X is the first size D1, and the maximum size of the columnar structure 211 in the second film layer 202 cut by a plane perpendicular to its extension direction X is the second size D2. The first size D1 is greater than the second size D2.

[0095] By matching the refractive index relationship with the cross-sectional dimensions of the columnar structures in the first and second films, it is beneficial to further achieve diffraction and interference effects on specific color image light, thereby increasing the brightness of the specific color image light incident on the light-emitting surface 104.

[0096] For example, such as Figure 8 As shown, the cross-sectional shapes of the columnar structures 211 in the first membrane layer 201 and the second membrane layer 202, when cut by a plane perpendicular to their extension direction X, can be the same, such as both being circular, elliptical, or hexagonal, or they can be different, such as the cross-sectional shape of the columnar structure in one layer being circular, and the cross-sectional shape of the columnar structure in the other layer being elliptical or hexagonal. For example, the maximum dimension can be the diameter of a circle, the major axis of an ellipse, or the diagonal of a hexagon.

[0097] Figure 8The diagram schematically shows that the cross-sectional dimensions of the columnar structures 211 in the first film layer 201 and the second film layer 202 in the first light adjustment structure 200 are different, but it is not limited to this. The cross-sectional dimensions of the columnar structures in the first film layer and the second film layer in the second light adjustment structure 300 can also be different. For example, only the cross-sectional dimensions in the first light adjustment structure 200 can have the above relationship, or only the cross-sectional dimensions in the second light adjustment structure 300 can have the above relationship, or both the cross-sectional dimensions in the first light adjustment structure 200 and the second light adjustment structure 300 can have the above relationship.

[0098] Figure 9 for Figure 5 The diagram shows a first ray adjustment structure set on the first prism surface of the optical system in another example. Figure 10 for Figure 5 The optical system shown is illustrated in another example with a second prism surface equipped with a second light adjustment structure.

[0099] Figure 9 The first light adjustment structure 200 shown is... Figure 6 The difference in the first light adjustment structure 200 shown is whether at least part of the columnar structure is tilted. Figure 10 The second light adjustment structure 300 shown is... Figure 7 The difference in the second light adjustment structure 300 shown is whether at least part of the columnar structure is tilted. For ease of illustration, Figure 9 The second light adjustment structure between the first prism 110 and the fourth prism 140 is omitted. Figure 10 The first ray adjustment structure between the first prism 110 and the third prism 130 is omitted.

[0100] In some examples, such as Figure 5 , Figure 9 and Figure 10 As shown, in the first light adjustment structure 200 and the second light adjustment structure 300, the columnar structures in at least a portion of the area are inclined. The angle between the extension direction X of the inclined columnar structure and the normal of the prism surface is 15 to 30 degrees. The tilt angle of the columnar structure 211 in the first light adjustment structure 200 is different from that of the columnar structure 311 in the second light adjustment structure 300.

[0101] By tilting the columnar structures in certain areas of the first light adjustment structure 200 and the second light adjustment structure 300, the propagation direction of specific wavelength image light incident on the tilted columnar structures can be further changed, allowing more light to be concentrated in the target direction. If the light-emitting surface 104 of the prism group 100 is provided with other lens groups (not shown), the tilted columnar structures ensure that light emitted from the light-emitting surface 104 of the prism group 100 can essentially enter the aforementioned lens groups, reducing light loss. Furthermore, by setting different tilt angles for the columnar structures in the first light adjustment structure 200 and the second light adjustment structure 300, the wavelengths of the first color image light 501 and the second color image light 502 can be matched, respectively.

[0102] In the optical system disclosed herein, a specific angled columnar structure is used to guide reflected light to propagate in the desired direction, reducing unnecessary light loss; the columnar structure deviating from the normal can be adjusted for the diffraction direction of the corresponding color image light, ensuring the maximum functionality of the multilayer film and improving the brightness and uniformity of the optical system.

[0103] The tilted columnar structure alters the relationship between the incident angle and the deflection angle of incident light of a specific wavelength, thereby guiding image light of that wavelength along the target direction. In multilayer stacking, the tilted columnar structure can optimize the interference effect between multilayer films by fine-tuning the path of the incident light, thereby increasing the reflection intensity of specific wavelengths, such as the target wavelength, concentrating more energy in the target direction, reducing the transmission and scattering of image light of that specific wavelength towards non-target directions, reducing stray light, and improving optical purity.

[0104] For example, such as Figure 9 and Figure 10 As shown, in at least one of the first light adjustment structure 200 and the second light adjustment structure 300, the columnar structures may be inclined only in a portion of the region. For example, columnar structures with the same angle of inclination may be closely arranged. For example, the extending direction of the columnar structures in a portion of the region may be parallel to the normal direction of the prism surface in which they are located.

[0105] In some examples, such as Figure 5 , Figure 9 and Figure 10As shown, at least one of the first prism surface 105 and the second prism surface 106 includes a first distribution area 010, a second distribution area 020, and a third distribution area 030 arranged sequentially. The orthographic projections of the first distribution area 010, the second distribution area 020, and the third distribution area 030 onto the light-emitting surface 104 are respectively a first area 001, a second area 002, and a third area 003 arranged sequentially along the arrangement direction of the first light-incident surface 101 and the second light-incident surface 102. Along the arrangement direction, the size ratio of the first area, the second area, and the third area is 1:8:1. The columnar structures located at least in the first distribution area 010 and the third distribution area 030 are inclined, with the columnar structure in the first distribution area 010 inclined towards the second distribution area 020, and the columnar structure in the third distribution area 030 inclined towards the second distribution area 020. The first distribution area 010 and the third distribution area 030 can be interchanged.

[0106] In the optical system disclosed herein, by setting the columnar structures located in different distribution areas to have different tilt directions, it is beneficial to adjust the propagation direction of light emitted from different positions of the display screen, thereby achieving the effect of light collection.

[0107] For example, such as Figure 10 As shown, along the direction parallel to the prism surface where the columnar structure is located, such as the Z direction, the size ratio of the first distribution area 010, the second distribution area 020, and the third distribution area 030 can be 1:8:1.

[0108] like Figure 5 and Figure 9 As shown, the first color image light 501 incident from the first position 1011 of the first incident surface 101 onto the first distribution area 010 is adjusted by the inclined columnar structure 211 so that its outgoing light converges toward the second area 002, instead of as before. Figure 4 As shown, the light is deflected downwards; the first color image light 501 incident from the second position 1012 of the first incident surface 101 into the third distribution area 030 is adjusted by the inclined columnar structure 211 so that its outgoing light converges towards the second area 002. Thus, the inclined columnar structure achieves the light collection effect through diffraction.

[0109] like Figure 5 and Figure 10 As shown, the second color image light 502 incident from the third position 1021 of the second light-incident surface 102 into the first distribution area 010 is adjusted by the inclined columnar structure 311 to converge towards the second area 002; the second color image light 502 incident from the fourth position 1022 of the second light-incident surface 102 into the third distribution area 030 is adjusted by the inclined columnar structure 311 to converge towards the second area 002, instead of... Figure 4As shown, the upward deflection of the inclined columnar structure enables light collection through diffraction.

[0110] For example, such as Figure 9 and Figure 10 As shown, the tilt angle of the columnar structure located in the first distribution area 010 relative to the normal of the prism surface is the first value, and the tilt angle of the columnar structure located in the third distribution area 030 relative to the normal of the prism surface is the second value. According to the incident angle of the light rays of the columnar structures in these two distribution areas, the first value and the second value can be adjusted accordingly. For example, the first value and the second value can be equal or unequal.

[0111] For example, such as Figure 9 and Figure 10 As shown, the extension direction of each columnar structure in the first distribution area 010 has the same angle as the normal of the prism surface, the extension direction of each columnar structure in the second distribution area 020 has the same angle as the normal of the prism surface, and the extension direction of each columnar structure in the third distribution area 030 has the same angle as the normal of the prism surface.

[0112] By setting the angle of the columnar structures located in the same distribution area, it is beneficial to adjust the deflection angle of light rays incident on the columnar layer from different positions on the incident surface, while saving process time.

[0113] For example, such as Figure 9 and Figure 10 As shown, gaps can be set between columnar structures located in adjacent distribution areas and adjacent to each other, while there are no gaps between adjacent columnar structures located in the same distribution area.

[0114] For example, such as Figure 9 and Figure 10 As shown, within the same distribution area, the tilt angles of columnar structures in different layers can be the same. However, this is not the case; within the same distribution area, the tilt angles of columnar structures in different layers can be adjusted to be different as needed.

[0115] For example, such as Figure 9 and Figure 10 As shown, the first distribution area 010, the second distribution area 020, and the third distribution area 030 can be regions extending in a direction perpendicular to the paper, that is, regions extending in a direction perpendicular to the YZ plane.

[0116] In some examples, such as Figure 9 and Figure 10As shown, the maximum dimension D01 of the cross section of the columnar structure 211 in the first light adjustment structure 200 cut by a plane perpendicular to its extension direction is different from the maximum dimension D02 of the cross section of the columnar structure 311 in the second light adjustment structure 300 cut by a plane perpendicular to its extension direction, and the height H01 of the columnar structure 211 in the first light adjustment structure 200 is different from the height H02 of the columnar structure 311 in the second light adjustment structure 300.

[0117] In some examples, such as Figure 9 and Figure 10 As shown, the first color image light 501 is red image light with a first wavelength, and the second color image light 502 is blue image light with a second wavelength. In the first light adjustment structure 200, the maximum size D01 of the cross-section of the columnar structure 211 cut by a plane perpendicular to its extension direction is 100-200 nanometers, and the thickness of each film layer in the first light adjustment structure 200 is one-quarter of the first wavelength. In the second light adjustment structure 300, the maximum size D02 of the cross-section of the columnar structure 311 cut by a plane perpendicular to its extension direction is 50-100 nanometers, and the thickness of each film layer in the second light adjustment structure 300 is one-quarter of the second wavelength.

[0118] For example, the first wavelength can be any value in the range of 571 to 750 nanometers, and the second wavelength can be any value in the range of 350 to 495 nanometers.

[0119] For example, such as Figure 9 and Figure 10 As shown, D01 can be 100 nanometers, or 200 nanometers, or 120-180 nanometers, or 130-170 nanometers, or 150-190 nanometers, etc. In this embodiment of the disclosure, the specific values ​​of the maximum cross-section of the columnar structure cut by a plane perpendicular to its extension direction are not listed one by one, and can be any value in the range of 100-200 nanometers.

[0120] For example, such as Figure 9 and Figure 10 As shown, D02 can be 50 nanometers, 100 nanometers, 60-80 nanometers, or 70-90 nanometers, etc. In this embodiment, the specific values ​​of the maximum cross-section of the columnar structure cut by a plane perpendicular to its extension direction are not listed one by one, and can be any value in the range of 50-100 nanometers.

[0121] In some examples, such as Figure 9 and Figure 10As shown, in the first light adjustment structure 200, the angle between the columnar structure 211 and the normal N1 of the first prism surface 105 is the first angle θ1, and in the second light adjustment structure 300, the angle between the columnar structure 311 and the normal N2 of the second prism surface 106 is the second angle θ2. The first angle θ1 is greater than the second angle θ2.

[0122] By setting the parameters of the columnar structures in the first light adjustment structure 200 and the second light adjustment structure 300, the phase of the first color image light 501 can be matched by the first light adjustment structure 200, and the phase of the second color image light 502 can be matched by the second light adjustment structure 300. This improves the reflectivity and uniformity of the first color image light 501 and the second color image light 502, reduces the influence on the transmissivity of the third color image light 503, and reduces color shift.

[0123] In some examples, such as Figure 9 and Figure 10 As shown, the first included angle θ1 is 15 to 25 degrees, and the second included angle θ2 is 20 to 30 degrees.

[0124] For example, such as Figure 9 and Figure 10 As shown, the first included angle can be 15 degrees, or 16 degrees, or 17 degrees, or 18 degrees, or 19 degrees, or 20 degrees, or 21 degrees, or 22 degrees, or 23 degrees, or 24 degrees, or 25 degrees. This embodiment of the disclosure does not list all the specific angles of the first included angle; the first included angle can be any angle between 15 and 25 degrees. For example, the second included angle can be 20 degrees, or 21 degrees, or 22 degrees, or 23 degrees, or 24 degrees, or 25 degrees, or 26 degrees, or 27 degrees, or 28 degrees, or 29 degrees, or 30 degrees. This embodiment of the disclosure does not list all the specific angles of the second included angle; the second included angle can be any angle between 20 and 30 degrees.

[0125] Figure 11 This is a schematic diagram of an optical system provided according to another example of an embodiment of the present disclosure.

[0126] Figure 11 The optical system shown is Figure 5 The difference in the optical system shown is that: Figure 11 The optical system shown also includes a third light adjustment structure 400.

[0127] In some examples, such as Figure 11 As shown, the third light-incident surface 103 is provided with a third light-adjusting structure 400, which is configured to transmit third color image light 503; the third light-adjusting structure 400 includes one or more film layers, and the one or more film layers include at least one columnar layer 410.

[0128] By providing a third light-adjusting structure 400 including a columnar layer on the third light-incident surface 103, it is beneficial to improve the transmittance of the third color image light 503, thereby reducing the reflection of the third color image light 503 by the third light-incident surface 103.

[0129] In some examples, such as Figure 11 As shown, in the third light adjustment structure 400, columnar structures 411 are closely arranged, and the maximum dimension D03 of the cross section of the columnar structure 411 cut by a plane perpendicular to its extension direction is 150-250 nanometers; the green image light has a third wavelength, and the thickness of each film layer in one or more layers is one-quarter of the third wavelength.

[0130] For example, the third wavelength can be any value in the range of 496 to 570 nanometers.

[0131] In some examples, such as Figure 11 As shown, in the third light adjustment structure 400, the number of one or more film layers is no more than 10.

[0132] By setting the parameters of the third light adjustment structure 400, high transmittance of the third color image light 503 to the third light adjustment structure 400 can be achieved.

[0133] For example, such as Figure 11 As shown, the maximum dimension D03 of the cross-section of the columnar structure 411 cut by a plane perpendicular to its extension direction can be 150 nanometers, 250 nanometers, 160-200 nanometers, or 170-190 nanometers, etc. In this embodiment, the specific values ​​of the maximum dimension D03 of the cross-section of the columnar structure cut by a plane perpendicular to its extension direction are not listed individually; it can be any value between 150 and 250 nanometers.

[0134] For example, such as Figure 11 As shown, the number of film layers in the third light adjustment structure 400 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 layers.

[0135] For example, such as Figure 11 As shown, each film layer in the third light adjustment structure 400 is a columnar layer 410. However, it is not limited to this; the third light adjustment structure 400 may also include other film layers that enhance the light transmission of the third color image light 503.

[0136] For example, such as Figure 11 As shown, in each columnar layer 410, adjacent columnar structures 411 are closely arranged.

[0137] In some examples, such as Figure 11 As shown, in the third light adjustment structure 400, the angle between the extension direction of the columnar structure 411 and the normal of the third incident light surface 103 is no greater than 10 degrees.

[0138] By setting the angle between the extension direction of the columnar structure in the third ray adjustment structure 400 and the normal of the third incident surface 103 to no more than 10 degrees, it is beneficial to achieve high transmittance of the third color image light 503.

[0139] For example, such as Figure 11 As shown, in the third light-adjusting structure 400, the angle between the extending direction of the columnar structure 411 and the normal of the third light-incident surface 103 can be 0 degrees, 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees, or 10 degrees. This embodiment of the present disclosure does not list the specific values ​​of the angle between the extending direction of the columnar structure and the normal of the third light-incident surface 103 in the third light-adjusting structure 400; it can be any angle not exceeding 10 degrees.

[0140] The included angles mentioned in the embodiments of this disclosure do not take into account the directionality of the included angles. For example, the numerical range of the included angles is the numerical range of the absolute value of the included angles.

[0141] Figure 11 The optical system shown, except for the third ray adjustment structure 400, can be connected with... Figure 5 The corresponding structures in the optical system shown have the same characteristics, and will not be described again here.

[0142] Figure 12 This is a partial structural schematic diagram of a display device according to another embodiment of the present disclosure.

[0143] like Figure 12 As shown, the display device includes multiple displays and any of the aforementioned optical systems. The multiple displays are arranged in a one-to-one correspondence with multiple light-incident surfaces, and different displays emit image light of different colors. Figure 12 The optical system is schematically shown as follows: Figure 5 The optical system shown is not limited to this; it can also be... Figure 11 The optical system shown.

[0144] For example, such as Figure 12As shown, the multiple displays include a first display 510, a second display 520, and a third display 530. The first display 510 emits a first color image light 501, the second display 520 emits a second color image light 502, and the third display 530 emits a third color image light 503. The first display 510 is positioned opposite to the first light-incident surface 101, the second display 520 is positioned opposite to the second light-incident surface 102, and the third display 530 is positioned opposite to the third light-incident surface 103. The different color image lights emitted from the different displays are transmitted through the prisms in the prism assembly 100 and diffracted and interfered by the first light-adjusting structure 200 and the second light-adjusting structure 300, and then combine at the light-emitting surface 104.

[0145] For example, such as Figure 12 As shown, the display screen can be any type of display screen, such as liquid crystal display screen, inorganic light-emitting diode display screen, organic light-emitting diode display screen, quantum dot display screen, etc.

[0146] For example, the display device can be an augmented reality (AR) display device.

[0147] For example, the display device can be a near-eye display device, such as a wearable helmet or glasses, but the embodiments disclosed herein are not limited thereto.

[0148] The following points need to be explained:

[0149] (1) The accompanying drawings of the embodiments of this disclosure only involve the structures involved in the embodiments of this disclosure, and other structures can be referred to the general design.

[0150] (2) Where there is no conflict, features of the same embodiment and different embodiments of this disclosure may be combined with each other.

[0151] The above description is merely an exemplary embodiment of this disclosure and is not intended to limit the scope of protection of this disclosure, which is determined by the appended claims.

Claims

1. An optical system, comprising: A prism assembly includes multiple incident light surfaces and one exit light surface. Each incident light surface is configured to receive image light of a single color. Different incident light surfaces are configured to receive image light of different colors. The different color image lights converge in the prism assembly and exit from the exit light surface. The prism group includes multiple prisms, with a first light adjustment structure and a second light adjustment structure sandwiched between the multiple prisms. The different color image light includes at least a first color image light and a second color image light. The first light adjustment structure is configured to change the propagation direction of the first color image light and transmit at least one other color image light besides the first color image light. The second light adjustment structure is configured to change the propagation direction of the second color image light and transmit at least one other color image light besides the second color image light. Both the first light adjustment structure and the second light adjustment structure include multiple layers of film stacked together. At least one of the first light adjustment structure and the second light adjustment structure includes at least one columnar layer. Each columnar layer includes multiple columnar structures, and the columnar structures in at least a portion of the same columnar layer are closely arranged.

2. The optical system according to claim 1, wherein, In the same light adjustment structure of the first light adjustment structure and the second light adjustment structure, the multilayer film includes a first film and a second film alternately arranged in a direction perpendicular to the prism surface where the multilayer film is located. The refractive index of the first film is greater than the refractive index of the second film, and at least one of the first film and the second film is a columnar layer in the at least one columnar layer.

3. The optical system according to claim 2, wherein, Both the first film layer and the second film layer are columnar layers, and the height of the columnar structure in the first film layer is equal to the height of the columnar structure in the second film layer.

4. The optical system according to claim 3, wherein, The maximum dimension of the columnar structure in the first film layer cut by a plane perpendicular to its extension direction is the first dimension, and the maximum dimension of the columnar structure in the second film layer cut by a plane perpendicular to its extension direction is the second dimension, wherein the first dimension is greater than the second dimension.

5. The optical system according to claim 1, wherein, The prism assembly includes a first prism surface with the first light adjustment structure and a second prism surface with the second light adjustment structure. The first prism surface intersects with the second prism surface. Both the first light adjustment structure and the second light adjustment structure include a columnar layer in the at least one columnar layer. In the first light adjustment structure and the second light adjustment structure, the columnar structures in at least a portion of the region are inclined, and the angle between the extension direction of the inclined columnar structure and the normal of the prism surface is 15 to 30 degrees. Furthermore, the inclination angle of the columnar structure in the first light adjustment structure is different from that in the second light adjustment structure.

6. The optical system according to claim 5, wherein, The plurality of light-incident surfaces include a first light-incident surface, a second light-incident surface, and a third light-incident surface. The first light-incident surface and the second light-incident surface are arranged opposite to each other, and the third light-incident surface is arranged opposite to the light-out surface. One of the first color image light and the second color image light is incident into the prism group from the first light-incident surface, and the other of the first color image light and the second color image light is incident into the prism group from the second light-incident surface. At least one of the first prism surface and the second prism surface includes a first distribution area, a second distribution area and a third distribution area arranged in sequence. The orthographic projections of the first distribution area, the second distribution area and the third distribution area on the light-emitting surface are respectively the first area, the second area and the third area arranged in sequence along the arrangement direction of the first light-incident surface and the second light-incident surface. Along the arrangement direction, the size ratio of the first area, the second area and the third area is 1:8:

1. The columnar structures located at least in the first distribution area and the third distribution area are inclined, with the columnar structures located in the first distribution area inclined toward the second distribution area, and the columnar structures located in the third distribution area inclined toward the second distribution area.

7. The optical system according to claim 6, wherein, The maximum dimension of the cross-section of the columnar structure in the first light adjustment structure cut by a plane perpendicular to its extension direction is different from the maximum dimension of the cross-section of the columnar structure in the second light adjustment structure cut by a plane perpendicular to its extension direction, and the height of the columnar structure in the first light adjustment structure is different from the height of the columnar structure in the second light adjustment structure.

8. The optical system according to claim 7, wherein, The first color image light is red image light, and the second color image light is blue image light; The different color image light also includes a third color image light, which is green image light, and the third color image light is incident on the prism group from the third light-incident surface; The first light adjustment structure is configured to transmit the second color image light and the third color image light, and the second light adjustment structure is configured to transmit the first color image light and the third color image light.

9. The optical system according to claim 8, wherein, The red image light has a first wavelength, and the blue image light has a second wavelength; In the first light adjustment structure, the maximum size of the cross-section of the columnar structure cut by a plane perpendicular to its extension direction is 100-200 nanometers, and the thickness of each film layer in the first light adjustment structure is one-quarter of the first wavelength. In the second light adjustment structure, the maximum size of the cross-section of the columnar structure cut by a plane perpendicular to its extension direction is 50 to 100 nanometers, and the thickness of each film layer in the second light adjustment structure is one-quarter of the second wavelength.

10. The optical system according to claim 9, wherein, In the first light adjustment structure, the angle between the columnar structure and the normal of the first prism surface is the first angle, and in the second light adjustment structure, the angle between the columnar structure and the normal of the second prism surface is the second angle, wherein the first angle is greater than the second angle.

11. The optical system according to claim 10, wherein, The first included angle is 15 to 25 degrees, and the second included angle is 20 to 30 degrees.

12. The optical system according to claim 8, wherein, The third light-incident surface is provided with a third light-adjusting structure, which is configured to transmit the third color image light. The third light adjustment structure includes one or more film layers, and the one or more film layers include the at least one columnar layer.

13. The optical system according to claim 12, wherein, In the third light adjustment structure, the columnar structures located in the same columnar layer are closely arranged, and the maximum size of the cross-section of the columnar structure cut by a plane perpendicular to its extension direction is 150 to 250 nanometers. The green image light has a third wavelength, and the thickness of each of the one or more film layers is one-quarter of the third wavelength.

14. The optical system according to any one of claims 1-13, wherein, In the first light adjustment structure and the second light adjustment structure, which include at least one columnar layer, the number of the multilayer film layers is 2 to 100.

15. The optical system according to claim 14, wherein, The number of the multilayer film is 40 to 60.

16. The optical system according to claim 13, wherein, In the third light adjustment structure, the number of one or more film layers is no more than 10.

17. The optical system according to claim 13 or 16, wherein, In the third light-adjusting structure, the angle between the extension direction of the columnar structure and the normal of the third light-incident surface is no greater than 10 degrees.

18. A display device comprising a plurality of displays and an optical system according to any one of claims 1-17, wherein, The plurality of display screens are arranged in a one-to-one correspondence with the plurality of light-incident surfaces, and different display screens emit image light of different colors.

Images