Display device
Provided is a display device, which includes: a diffusion plate, where the diffusion plate includes: a substrate including a first surface and a second surface facing away from each other; and a micro-structure unit located on a side of the second surface of the substrate, where the micro-structure unit includes a third surface and a fourth surface facing away from each other, the third surface is connected to the second surface, and the fourth surface has a surface shape axis inclined relative to the first surface; and a light source located on a side of the first surface of the substrate, where the light source is configured to emit a light beam to be diffused to the micro-structure unit, and the light beam to be diffused passes through the micro-structure unit to form a diffused light field.
1 . A display device, comprising:
a diffusion plate, wherein the diffusion plate comprises:
a substrate comprising a first surface and a second surface facing away from each other; and
a micro-structure unit located on a side of the second surface of the substrate, wherein the micro-structure unit comprises a third surface and a fourth surface facing away from each other, the third surface is connected to the second surface, and the fourth surface has a surface shape axis inclined relative to the first surface; and
a light source located on a side of the first surface of the substrate, wherein the light source is configured to emit a light beam to be diffused to the micro-structure unit, the light beam to be diffused has a chief ray inclined relative to the first surface and emitted from the light source at an original direction, and the light beam to be diffused passes through the micro-structure unit to form a diffused light field, wherein the chief ray is located at a center of the light beam to be diffused and maintains the original direction after passing through the micro-structure unit, and a center of the diffused light field is located on the chief ray; and
wherein an inclined direction of the surface shape axis relative to the first surface is opposite to an inclined direction of the first surface relative to the chief ray, so that the light beam to be diffused passes through the micro-structure unit to form the diffused light field with the center of the diffused light field located on the chief ray,
wherein the diffusion plate comprises a plurality of micro-structure units, and inclined surface shape axes of all micro-structure units on the second surface of the substrate have a given direction opposite to the inclined direction of the first surface relative to the chief ray.
2 . The display device according to claim 1 , wherein a surface shape of the fourth surface is rotationally symmetrical relative to the surface shape axis.
3 . The display device according to claim 1 , wherein at the second surface, there are a first direction and a second direction perpendicular to each other, micro-structure units are arranged in the first direction and the second direction respectively, and adjacent micro-structure units are adhered to each other.
4 . The display device according to claim 3 , wherein heights of the micro-structure units are equal relative to the first surface of the substrate.
5 . The display device according to claim 3 , wherein heights of the micro-structure units are not equal relative to the first surface of the substrate.
6 . The display device according to claim 3 , wherein the third surface of the micro-structure unit is rectangular.
7 . The display device according to claim 3 , wherein
a distance a in the first direction, from an intersection of the surface shape axis of the fourth surface of the micro-structure unit and the fourth surface of the micro-structure unit to an intersection of a surface shape axis of a fourth surface of an adjacent micro-structure unit and the fourth surface of the adjacent micro-structure unit, satisfies 66 μm<a<70 μm; and
a distance b in the second direction, from the intersection of the surface shape axis of the fourth surface of the micro-structure unit and the fourth surface of the micro-structure unit to an intersection of a surface shape axis of a fourth surface of an adjacent micro-structure unit and the fourth surface of the adjacent micro-structure unit, satisfies 32 μm<b<36 μm.
8 . The display device according to claim 7 , wherein a curvature coefficient of the surface shape of the fourth surface at the surface shape axis of the fourth surface is 0.05 μm−1 and a conical coefficient of the surface shape of the fourth surface is −1.68; the distance a in the first direction, from the intersection of the surface shape axis of the fourth surface of the micro-structure unit and the fourth surface of the micro-structure unit to the intersection of the surface shape axis of the fourth surface of the adjacent micro-structure unit and the fourth surface of the adjacent micro-structure unit, is 68 μm; the distance b in the second direction, from the intersection of the surface shape axis of the fourth surface of the micro-structure unit and the fourth surface of the micro-structure unit to the intersection of the surface shape axis of the fourth surface of the adjacent micro-structure unit and the fourth surface of the adjacent micro-structure unit, is 33 μm.
9 . The display device according to claim 7 , wherein a curvature coefficient of the surface shape of the fourth surface at the surface shape axis of the fourth surface is 0.0362 μm−1 and a conical coefficient of the surface shape of the fourth surface is −1.68; the distance a in the first direction, from the intersection of the surface shape axis of the fourth surface of the micro-structure unit and the fourth surface of the micro-structure unit to the intersection of the surface shape axis of the fourth surface of the adjacent micro-structure unit and the fourth surface of the adjacent micro-structure unit, is 68 μm; the distance b in the second direction, from the intersection of the surface shape axis of the fourth surface of the micro-structure unit and the fourth surface of the micro-structure unit to the intersection of the surface shape axis of the fourth surface of the adjacent micro-structure unit and the fourth surface of the adjacent micro-structure unit, is 34.4 μm.
10 . The display device according to claim 1 , wherein the fourth surface is a rotationally symmetric aspheric surface.
11 . The display device according to claim 1 , wherein a uniformity of the diffused light field is greater than 90%.
12 . The display device according to claim 1 , wherein a ratio of a sinusoidal value of an inclined angle 0 between the chief ray and a normal of the first surface to a sinusoidal value of an inclined angle α between the surface shape axis and the normal of the first surface is equal to a value of a refractive index n of a material of the micro-structure unit.
13 . The display device according to claim 12 , wherein the inclined angle θ between the chief ray and the normal of the first surface satisfies θ≤40°.
14 . The display device according to claim 12 , wherein one of two adjacent micro-structure units is provided with an overlapping portion overlapping a fourth surface of another micro-structure unit.
15 . The display device according to claim 12 , wherein the inclined angle between the normal of the first surface of the diffusion plate and the chief ray is 27°, and the inclined angle between the surface shape axis of the fourth surface and the normal of the first surface is 17.7°.
16 . The display device according to claim 12 , wherein the inclined angle between the normal of the first surface of the diffusion plate and the chief ray is 15°, and the inclined angle between the surface shape axis of the fourth surface and the normal of the first surface is 10°.
17 . The display device according to claim 1 , wherein an inclined angle between the surface shape axis and a normal of the first surface ranges from 10° to 20°.
18 . The display device according to claim 1 , wherein a surface shape of the fourth surface is a quadratic or free-form surface.
19 . The display device according to claim 1 , wherein a material of the substrate is quartz glass, polymethyl methacrylate, or non-shadow glue.