Rear projection screen

• US 10,444,616 B2
• Filed: 03/19/2018
• Issued: 10/15/2019
• Est. Priority Date: 03/29/2017
• Status: Active Grant

• Current Assignee: Coretronic Corporation
• Original Assignee: Nano Precision Taiwan Limited
• Inventors: Li, Ching-Hsiang, Su, Fang-Hsuan, Yang, Shu-Ping, Hsieh, Chi-Tang, Hsu, Fu-Chiang, Chien, Hung-Ta
• Primary Examiner(s): Mahoney, Christopher E
• Application Number:
  US15/925,668
• Publication Number:
  US 20180284593A1
• Time in Patent Office: 575 Days
• Field of Search: 359460
• CPC Class Codes: G02B 27/0972 Prisms prisms per se G02B5/04
• CPC Class Codes: G02B 5/003 Light absorbing elements
• CPC Class Codes: G02B 5/0231 the surface having microprismatic or micropyramidal shape macroscopic prism arrays G02B5/045
• CPC Class Codes: G03B 21/62 Translucent screens

Abstract

A rear projection screen includes a transparent substrate, a light absorbing film and a first diffusion film in sequence from a projection side to a viewer side. The transparent substrate includes a first surface and a second surface opposite to each other, the first surface faces the projection side, the second surface faces the viewer side, and the first surface is disposed with a plurality of prism structures protruding toward the projection side. The transparent substrate is located between the light absorbing film and the prism structures. The light absorbing film includes a plurality of light absorbing structures arranged at intervals from each other, and the distribution density of the prism structures is greater than that of the light absorbing structures. The light absorbing film is located between the first diffusion film and the transparent substrate. The rear projection screen through the above-mentioned design has a good image display quality.

Claims

1. A rear projection screen, comprising a transparent substrate, a light absorbing film, and a first diffusion film in sequence from a projection side to a viewer side, wherein,

the transparent substrate comprises a first surface and a second surface opposite to the first surface, the first surface faces the projection side, the second surface faces the viewer side, and the first surface is disposed with a plurality of prism structures protruding toward the projection side;

the transparent substrate is located between the light absorbing film and the prism structures, the light absorbing film comprises a plurality of light absorbing structures arranged at intervals from each other, wherein each of the light absorbing structures is a columnar structure tapered from the projection side toward the viewer side, and a distribution density of the prism structures is greater than a distribution density of the light absorbing structures;

the light absorbing film is located between the first diffusion film and the transparent substrate.

2. The rear projection screen according to claim 1, further comprising a second diffusion film located between the light absorbing film and the transparent substrate, wherein the second diffusion film comprises a first diffusion layer, an adhesive layer, and a second diffusion layer in sequence from the projection side to the viewer side, and the first diffusion layer is disposed on the second surface of the transparent substrate.

3. The rear projection screen according to claim 2, wherein a surface of the first diffusion layer and a surface of the second diffusion layer are roughened, the adhesive layer is disposed between the first diffusion layer and the second diffusion layer, and a refractive index of the first diffusion layer and a refractive index of the second diffusion layer are greater than a refractive index of the adhesive layer.

4. The rear projection screen according to claim 1, wherein the first diffusion film comprises a sheet substrate, and the sheet substrate comprises a plurality of diffusion particles.

5. The rear projection screen according to claim 1, wherein the first diffusion film comprises a substrate and a plurality of microstructures disposed on the substrate, and each of the microstructures comprises a plurality of diffusion particles.

6. The rear projection screen according to claim 5, wherein each of the microstructures has a long axis, a short axis, and a thickness, the long axis is parallel to an extending direction of the microstructure, and a length of the long axis, a length of the short axis and the thickness of the microstructures vary randomly.

7. The rear projection screen according to claim 5, wherein each of the microstructures is a hemispherical three-dimensional structure, a semi-ellipsoidal three-dimensional structure or a semi-cylindrical three-dimensional structure in which an arc bending protrudes toward the viewer side.

8. The rear projection screen according to claim 1, wherein the prism structures are arranged in a distribution direction, each of the prism structures is a columnar structure extending in an extending direction, and the distribution direction and the extending direction are not parallel to each other.

9. The rear projection screen according to claim 1, wherein the transparent substrate further comprises an axis, and the prism structures are in a concentric annular distribution from the axis along a radial direction.

10. The rear projection screen according to claim 1, wherein the transparent substrate further comprises a plurality of diffusion particles.

11. The rear projection screen according to claim 1, further comprising a prism film, wherein the prism film is disposed on the first surface of the transparent substrate, and the prism structures are disposed on a surface of the prism film facing the projection side.

12. The rear projection screen according to claim 11, wherein the prism film comprises a plurality of diffusion particles, and the diffusion particles are distributed within the prism structures.

13. The rear projection screen according to claim 1, wherein the light absorbing film further comprises a plurality of light-transmitting portions, the light-transmitting portions and the light absorbing structures are staggered with each other in a distribution direction respectively, each of the light absorbing structures is a columnar structure extending in an extending direction, and the distribution direction and the extending direction are not parallel to each other.

14. The rear projection screen according to claim 13, wherein the light absorbing structures of the light absorbing film have an arrangement period P in the distribution direction, each of the light absorbing structures has a thickness H, and the light absorbing structures satisfy:

H/P<

2.

15. The rear projection screen according to claim 13, wherein each of the light absorbing structures is the columnar structure tapered from the projection side toward the viewer side, a maximum width of each of the light absorbing structures in the distribution direction is greater than 10 microns, each of the light absorbing structures comprises a first slope and a second slope extending in the extending direction, the first slope connects the second slope, and an angle between the first slope and the second slope is less than 28 degrees.

16. The rear projection screen according to claim 1, wherein a surface of the first diffusion film facing the viewer side is coated with an anti-reflection coating or an anti-glare coating.

17. A rear projection screen, comprising a transparent substrate, a diffusion film, and a light absorbing film in sequence from a projection side to a viewer side, wherein,

the transparent substrate comprises a first surface and a second surface opposite to the first surface, the first surface faces the projection side, the second surface faces the viewer side, and the first surface is disposed with a plurality of prism structures protruding toward the projection side;

the transparent substrate is located between the light absorbing film and the prism structures, the light absorbing film comprises a plurality of light absorbing structures arranged at intervals from each other, wherein each of the light absorbing structures is a columnar structure tapered from the prosection side toward the viewer side, and a distribution density of the prism structures is greater than a distribution density of the light absorbing structures;

the diffusion film is located between the light absorbing film and the transparent substrate.

18. The rear projection screen according to claim 17, wherein the diffusion film comprises a first diffusion layer, an adhesive layer and a second diffusion layer in sequence from a projection side to a viewer side, and the first diffusion layer is disposed on the second surface of the transparent substrate.

19. The rear projection screen according to claim 18, wherein a surface of the first diffusion layer and a surface of the second diffusion layer are roughened, the adhesive layer is disposed between the first diffusion layer and the second diffusion layer, and a refractive index of the first diffusion layer and a refractive index of the second diffusion layer are greater than a refractive index of the adhesive layer.

20. The rear projection screen according to claim 17, wherein the prism structures are arranged in a distribution direction, each of the prism structures are a columnar structure extending in an extending direction, and the distribution direction and the extending direction are not parallel to each other.

21. The rear projection screen according to claim 17, wherein the transparent substrate further comprises an axis, and the prism structures are in a concentric annular distribution from the axis along a radial direction.

22. The rear projection screen according to claim 17, wherein the light absorbing film further comprises a plurality of light-transmitting portions, the light-transmitting portions and the light absorbing structures are staggered with each other in a distribution direction respectively, each of the light absorbing structures is a columnar structure extending in an extending direction, and the distribution direction and the extending direction are not parallel to each other.

23. The rear projection screen according to claim 22, wherein the light absorbing structures of the light absorbing film have an arrangement period P in the distribution direction, each of the light absorbing structure has a thickness H, and the light absorbing structures satisfy:

H/P<

2.

24. The rear projection screen according to claim 22, wherein each of the light absorbing structures is the columnar structure tapered from the projection side toward the viewer side, a maximum width of each of the light absorbing structures in the distribution direction is greater than 10 microns, each of the light absorbing structures comprises a first slope and a second slope extending in the extending direction, and an angle between the first slope and the second slope is less than 28 degrees.