Display device incorporating reflective and retroreflective elements

• US 10,268,070 B2
• Filed: 04/04/2017
• Issued: 04/23/2019
• Est. Priority Date: 04/05/2016
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Koito, Takeo, Numata, Yudai
• Primary Examiner(s): Font, Frank G
• Application Number:
  US15/478,579
• Publication Number:
  US 20170285402A1
• Time in Patent Office: 749 Days
• Field of Search: 35948501, 35948907, 359530, 359614, 349 96
• CPC Class Codes: G02B 30/56 by projecting aerial or floating images
• CPC Class Codes: G02B 5/12 Reflex reflectors
• CPC Class Codes: G02B 5/124 plural reflecting elements forming part of a unitary plate or sheet
• CPC Class Codes: G02B 5/128 transparent spheres being embedded in matrix
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation

Abstract

According to one embodiment, a display device includes an optical element which transmits or reflects incident light, and a first reflective element including a first reflective portion and a second reflective portion. The first reflective portion retroreflects reflective light reflected on the optical element. The second reflective portion has an area less than an area of the first reflective portion and regularly reflects the reflective light.

Claims

1. A display device comprising:

a display module emitting light;

an optical element urging incident light emitted from a light source to be transmitted or reflected; and

a first reflective element comprising a first reflective portion on which the light reflected on the optical element is retroreflected, and a second reflective portion on which the light reflected on the optical element is specularly reflected, wherein

the second reflective portion has an area less than area of the first reflective portion, is surrounded by the first reflective portion, and is provided in a zigzag pattern.

2. The device of claim 1, further comprising

a second reflective element on which the light specularly reflected on the first reflective element is retroreflected.

3. The device of claim 1, wherein

the first reflective element makes an acute angle with the optical element.

4. The device of claim 1, wherein

the first reflective portion radially extends from a center, and comprises first to third reflective surfaces intersecting each other,

the second reflective portion is provided in first to third regions adjacent to a region in which the first reflective portion is located in plan view,

the first region is adjacent to the first and second reflective surfaces and is isolated from the center in plan view,

the second region is adjacent to the second and third reflective surfaces and is isolated from the center in plan view, and

the third region is adjacent to the third and first reflective surfaces and is isolated from the center in plan view.

5. The device of claim 4, wherein

the second reflective portion comprises a flat surface in each of the first to third regions.

6. The device of claim 4, wherein

the second reflective portion comprises a projecting portion which projects to a side away from the center.

7. The device of claim 1, wherein

the first reflective portion comprises a phototransmissive spherical member, and

the spherical member comprises:

a first curved surface on which the reflective light is refracted; and

a second curved surface on which the reflective light is reflected,

the first curved surface is located on a side close to the optical element, and

the second curved surface is located on a side away from the optical element.

8. A display device comprising:

a display module emitting light;

an optical element urging incident light emitted from a light source to be transmitted or reflected; and

a first reflective element comprising a first reflective portion in an uneven surface on which the reflective light reflected on the optical element is retroreflected, a second reflective portion on which the reflective light is specularly reflected, and a first plane opposed to the first reflective portion and the second reflective portion, wherein

the first reflective portion comprises first, second and third reflective surfaces being in contact with each other at a central point,

the first reflective surface is adjacent to the second and third reflective surfaces,

the second reflective surface is adjacent to the first and third reflective surfaces,

the third reflective surface is adjacent to the second and first reflective surfaces,

the second reflective portion is provided in first, second and third regions comprising a flat surface parallel to the first plane,

the first region is adjacent to the first and second reflective surfaces,

the second region is adjacent to the second and third reflective surfaces, and

the third region is adjacent to the third and first reflective surfaces.

9. The device of claim 8, wherein

the first reflective portion is depressed toward the central point.

10. The device of claim 8, wherein

the first region, the second region and the third region are isolated from each other.

11. The device of claim 8, further comprising:

a second reflective element on which the light specularly reflected on the first reflective element is retroreflected toward the first reflective element.

12. The device of claim 8, wherein

the first reflective portion comprises a phototransmissive spherical member, and

the spherical member comprises:

a first curved surface on which the reflective light is refracted; and

a second curved surface on which the reflective light is reflected,

the first curved surface is located on a side close to the optical element, and

the second curved surface is located on a side away from the optical element.

13. The device of claim 8, wherein

a total area of the first, second and third regions is less than a total area of the first, second and third reflective surfaces in plan view.

14. A display device comprising:

a display module emitting light;

an optical element urging incident light emitted from a light source to be transmitted or reflected; and

a first reflective element comprising a first reflective portion on which the reflective light reflected on the optical element is retroreflected, and a second reflective portion on which the reflective light is specularly reflected, wherein

the first reflective portion comprises first, second and third reflective surfaces being in contact with each other at a central point,

the first reflective surface is adjacent to the second and third reflective surfaces,

the second reflective surface is adjacent to the first and third reflective surfaces,

the third reflective surface is adjacent to the second and first reflective surfaces,

the second reflective portion is provided in projecting first, second and third regions,

the first region is adjacent to the first and second reflective surfaces,

the second region is adjacent to the second and third reflective surfaces, and

the third region is adjacent to the third and first reflective surfaces.

15. The device of claim 14, wherein

the first reflective portion is depressed toward the central point.

16. The device of claim 15, wherein

the first, second and third regions project in a direction opposite to a direction in which the first reflective portion is depressed.

17. The device of claim 14, further comprising:

a second reflective element on which the light specularly reflected on the first reflective element is retroreflected toward the first reflective element.

18. The device of claim 14, wherein

the first reflective portion comprises a phototransmissive spherical member, and

the spherical member comprises:

a first curved surface on which the reflective light is refracted; and

a second curved surface on which the reflective light is reflected,

the first curved surface is located on a side close to the optical element, and

the second curved surface is located on a side away from the optical element.

19. The device of claim 14, wherein

a total area of the first, second and third regions is less than a total area of the first, second and third reflective surfaces in plan view.