Luminous display element including an optical member for reflecting light in a direction opposite to an incident direction

• US 6,787,976 B2
• Filed: 10/05/2001
• Issued: 09/07/2004
• Est. Priority Date: 10/18/2000
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Tomikawa, Masahiko, Ueki, Shun, Minoura, Kiyoshi
• Primary Examiner(s): Patel, Ashok
• Assistant Examiner(s): Colón, German
• Application Number:
  US09/970,821
• Publication Number:
  US 20020043931A1
• Time in Patent Office: 1,068 Days
• Field of Search: 313/110-113, 313/498-512, 313/117, 313/114
• US Class Current: 313/110
• 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

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 display, comprising:

a plurality of pixels illuminated by a luminous display element;

said luminous display element comprising;

an emission layer comprising a plurality of thin film elements; and

a retro-reflector disposed on a back side of said emission layer.

2. The display according to claim 1, wherein a pitch of a unit structure of said retro-reflector is not more than 5 mm.

3. The display according to claim 1, wherein a pitch of a unit structure of said retro-reflector is not more than 1 mm.

4. The display according to claim 1, wherein said emission layer includes plural colors, and a size of a unit structure of said retro-reflector is not more than a size of dots of the colors.

5. The display according to claim 1, wherein said retro-reflector 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, said unit structure being in a form of an equilateral triangle in a plan view of the corner cube array, and

a light shielding process is performed on a part of the periphery of a base angle of the rectangular equilateral triangles, an a part corresponding to outsides of a regular hexagon that internally touches the equilateral triangle of the unit structure.

6. The display according to claim 1, wherein said retro-reflector comprises a corner cube array whose unit structure is made up of three squares.

7. The display according to claim 1, wherein said retro-reflector comprises corner cube array, and a light shielding process is performed on edges and apices of the come cube array.

8. The display according to claim 1, wherein a first light absorbing member which absorbs a non-retro-reflecting component of light reflected by the retro-reflector is provided on a front side of the retro-reflector, said non-retro-reflecting component of light passing through plural dots which are different from each other.

9. The display according to claim 8, wherein said first light absorbing member comprises a color filter layer which absorbs stray light guided from other dots.

10. The display according to claim 1, comprising a display panel including the emission layer and the retro-reflector, and

wherein a side light absorbing member is disposed to cover a side face of the display panel and absorb incident light.

11. The display according to claim 1, wherein said emission layer is an electroluminescence layer.

12. The display according to claim 1, wherein a light shielding process is performed on non-retro-reflected components of light reflected by the retro-reflector.

13. The display according to claim 1, wherein the retro-reflector is a corner cube array, and the display further comprises:

a first electrode comprising aluminum for applying a voltage to the emission layer; and

a transparent second electrode for applying a voltage to the emission layer,

wherein;

the first electrode, the emission layer, and the transparent second electrode are disposed in order on a slope of a corner cube of the retro-reflector, and a flattening film is provided on the transparent second electrode.

14. A luminous display element comprising:

on a back side of an emission layer, an optical member which reflects incident light in a direction substantially opposite an incident direction;

wherein a first light absorbing member comprises a louver, and absorbs a non-retro-reflecting component of light reflected by the optical member, and is provided on a front side of the optical member, said non-retro-reflecting component of light passing through plural dots which are different from each other.

15. A display comprising:

a plurality of pixels illuminated by a luminous display element;

said 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, said emission layer comprising a plurality of thin film elements; and

a retro-reflecting member disposed on a back side of the emission layer which reflects a light emitted from the emission layer,

wherein, when the emission layer is in the second state, said retro-reflecting member is adapted to reflect an image of a black part of an observer'"'"'s eye so as to realize a black state created by the observer viewing a reflected image of the black part of the observer'"'"'s eye.

16. The display according to claim 15, wherein said retro-reflecting member reflects incident light in a direction substantially opposite an incident direction.

17. The display according to claim 15, wherein a pitch of a unit structure of said retro-reflecting member is not more than ½

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

18. The display according to claim 15, wherein a pitch of a unit structure of said retro-reflecting member is not more than ½

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

19. The display according to claim 15, wherein said retro-reflecting member is any one of a corner cube array, a micro sphere array, and a microlens array.

20. The display according to claim 15, wherein said retro-reflecting member comprises a corner cube array, and a light shielding process is performed on edges and apices of the corner cube array.

21. The display according to claim 15, wherein a light shielding process is performed on non-retro-reflected components of light reflected by the retro-reflecting member.

22. The display according to claim 15, wherein the retro-reflector is a corner cube array, and the display further comprises:

a first electrode comprising aluminum for applying a voltage to the emission layer; and

a transparent second electrode for applying a voltage to the emission layer,

wherein;

the first electrode, the emission layer, and the transparent second electrode are disposed in order on a slope of a corner cube of the retro-reflector, and a flattening film is provided on the transparent second electrode.

23. A display, comprising:

a plurality of pixels illuminated by a luminous display element;

said luminous display element comprising;

an emission layer comprising a plurality of thin film elements; and

a retro-reflective member disposed on a back side of said emission layer, said retro-reflective member reflecting incident light in a direction substantially opposite to, and along an axis substantially parallel to, an incident direction over a range of directions of incident light.

24. The display according to claim 23, wherein a light shielding process is performed on non-retro-reflected components of light reflected by the retro-reflective member.

25. The display according to claim 23, wherein said retro-reflective 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, said unit structure being in a form of an equilateral triangle in a plan view of the corner cube array, and

a light shielding process is performed on a part of the periphery of a base angle of the rectangular equilateral triangles, an a part corresponding to outsides of a regular hexagon that internally touches the equilateral triangle of the unit structure.

26. The display according to claim 23, wherein said retro-reflective member comprises a corner cube array whose unit structure is made up of three squares.

27. The display according to claim 23, wherein said retro-reflective member comprises corner cube array, and a light shielding process is performed on edges and apices of the corner cube array.

28. The display according to claim 23, wherein a first light absorbing member which absorbs a non-retro-reflecting component of light reflected by the retro-reflective member is provided on a front side of the retro-reflective member, said non-retro-reflecting component of light passing through plural dots which are different from each other.

29. The display according to claim 28, wherein said first light absorbing member comprises a color filter layer having a black matrix which absorbs stray light guided from other dots.

30. The display according to claim 23, wherein the retro-reflector is a corner cube array, and the display further comprises:

a first electrode comprising aluminum for applying a voltage to the emission layer; and

a transparent second electrode for applying a voltage to the emission layer,

wherein;

the first electrode, the emission layer, and the transparent second electrode are disposed in order on a slope of a corner cube of the retro-reflector, and a flattening film is provided on the transparent second electrode.

31. A display comprising:

a plurality of pixels illuminated by a luminous display element;

said 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, said emission layer comprising a plurality of thin film elements; and

a reflecting member disposed on a back side of the emission layer which reflects a light emitted from the emission layer, said reflecting member being arranged to reflect an image of a black part of an observer'"'"'s eye thereby realizing a black state when the emission layer is in said second state without using a polarizer.

32. The display according to claim 31, wherein the retro-reflector is a corner cube array, and the display further comprises:

a first electrode comprising aluminum for applying a voltage to the emission layer; and

a transparent second electrode for applying a voltage to the emission layer,

wherein;

the first electrode, the emission layer, and the transparent second electrode are disposed in order on a slope of a corner cube of the retro-reflector, and a flattening film is provided on the transparent second electrode.

33. A display, comprising:

a plurality of pixels illuminated by a luminous display element;

said luminous display element comprising;

an emission layer comprising a plurality of thin film elements; and

a retro-reflective member disposed on back side of said emission layer, said retro-reflective member reflecting incident light in a direction substantially opposite to, and along an axis substantially parallel to, an incident direction over a range of directions of incident light, wherein a pitch of a unit structure of said retro-reflective member is less than 10 mm.

34. The display according to claim 33, wherein said pitch of a unit structure of said retro-reflective member is not more than 5 mm.

35. The display according to claim 34, wherein said pitch of a unit structure of said retro-reflective member is not more than 1 mm.

36. The display according to claim 33, wherein said pitch of a unit structure of said retro-reflective member is adapted to reflect an image of only a black part of an observer'"'"'s eye so as to realize a black state created by the observer viewing a reflected image of the black part of the observer'"'"'s eye.