Luminous display element

• US 20020043931A1
• Filed: 10/05/2001
• Published: 04/18/2002
• Est. Priority Date: 10/18/2000
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ueki, Shun, Minoura, Kiyoshi, Tomikawa, Masahiko
• Granted Patent: US 6,787,976 B2
• Time in Patent Office: Days
• US Class Current: 313/506
• CPC Class Codes: H01J 1/70 with protective, conductive, or reflective layers
• CPC Class Codes: H05B 33/22 characterised by the chemical or physical composition or the arrangement of auxiliary dielectric or reflective layers
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/856 comprising reflective means
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/878 comprising reflective means
• CPC Class Codes: H10K 59/8792 comprising light absorbing layers, e.g. black layers

Abstract

In a luminous display element, a retro-reflector is provided on the back side of an organic EL layer which includes an emission layer whose state changes between an emission state and a non-emission state. The retro-reflector includes a corner cube array, and reflects incident light in the same direction as an incident direction. A unit structure of the corner cube array is a form of a triangular pyramid which is made up of rectangular equilateral triangles having three faces, and a light shielding process is performed on the periphery of a base angle of the rectangular equilateral triangle. Thus, it is possible to prevent an image from being reflected, so that it is possible to provide the luminous display element whose contrast ratio and the utilization efficiency of emission are high.

Claims

1. A luminous display element comprising, on a back side of an emission layer, an optical member which reflects incident light in the same direction as an incident direction.

2. The luminous display element set forth in claim 1, wherein a pitch of a unit structure of said optical member is not more than 5 mm.

3. The luminous display element set forth in claim 1, wherein a pitch of a unit structure of said optical member is not more than 1 mm.

4. The luminous display element set forth in claim 1, wherein said emission layer includes plural colors, and a size of a unit structure of said optical member is not more than a size of dots of the colors.

5. The luminous display element set forth in claim 1, wherein said optical member comprises a corner cube array whose unit structure is in a form of a triangular pyramid which is made up of three rectangular equilateral triangles, and a light shielding process is performed on the periphery of a base angle of the rectangular equilateral triangles.

6. The luminous display element set forth in claim 1, wherein said optical member comprises a corner cube array whose unit structure is made up of three squares.

7. The luminous display element set forth in claim 1, wherein said optical member comprises corner cube array, and a light shielding process is performed on edges and apices of the corner cube array.

8. The luminous display element set forth in claim 1, wherein, a first light absorbing member which absorbs a non-retro-reflecting component of light reflected by the optical member is provided on a front side of the optical member.

9. The luminous display element set forth in claim 8, wherein said first light absorbing member comprises a color filter layer.

10. The luminous display element set forth in claim 8, wherein said first light absorbing member comprises a louver.

11. The luminous display element set forth in claim 1, comprising a display panel including the emission layer and the optical member is provided, and

wherein a second light absorbing member which is provided so as to cover a side face of the display panel and absorbs incident light is provided.

12. The luminous display element set forth in claim 1, wherein said emission layer is an electroluminescence layer.

14. The luminous display element set forth in claim 13, wherein said reflecting member reflects incident light in the same direction as an incident direction.

15. The luminous display element set forth in claim 13, wherein a pitch of a unit structure of said reflecting member is not more than ½

of a diameter of the black part of the observer'"'"'s eye.

16. The luminous display element set forth in claim 13, wherein a pitch of a unit structure of said reflecting member is not more than ½

of a diameter of the observer'"'"'s pupil.

17. The luminous display element set forth in claim 13, wherein said reflecting member is any one of a corner cube array, a micro sphere array, and a microlens array.

18. The luminous display element set forth in claim 13, wherein said optical member comprises a corner cube array, and a light shielding process is performed on edges and apices of the corner cube array.

13. A luminous display element comprising:

an emission layer whose state changes between a first state which is an emission state and a second state which is a non-emission state; and

a reflecting member which reflects a light emitted from the emission layer,

wherein, when the emission layer is in the second state, said reflecting member is adapted to reflect an image of a black part of an observer'"'"'s eye so as to realize a black state as the observer recognizes the image of the black part of his/her eye.