Display device having conical transparent members covering electroluminescent elements

• US 6,858,983 B2
• Filed: 11/27/2001
• Issued: 02/22/2005
• Est. Priority Date: 12/05/2000
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Hoshi, Hikaru, Mochizuki, Noritaka, Tokuda, Ryuji, Setani, Michitaka, Sakuranaga, Masanori
• Primary Examiner(s): Williams, Joseph
• Assistant Examiner(s): QUARTERMAN, KEVIN J
• Application Number:
  US09/993,672
• Publication Number:
  US 20020105267A1
• Time in Patent Office: 1,183 Days
• Field of Search: 313/512, 313/498, 313/506, 313/113, 349/62, 349/67, 349/69, 257/98, 257/99
• US Class Current: 313/512
• CPC Class Codes: H05B 33/00 Electroluminescent light sources
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 59/873 Encapsulations

Abstract

A display device includes a transparent substrate, a plurality of electroluminescent elements arranged on the transparent substrate, transparent members respectively covering the electroluminescent elements, and reflection films formed respectively on the surfaces of the transparent members. Each of the electroluminescent elements is formed by sequentially laying a transparent electrode, an electroluminescent layer and a reflector electrode on the transparent substrate. Each of the transparent members has a profile of a frustum of pyramid or cone, or partly has a curved surface showing a positive curvature and a curved surface showing a negative curvature at the portion held in contact with the transparent substrate.

Claims

1. A display device comprising:

a transparent substrate;

a plurality of electroluminescent elements arranged on said transparent substrate, each of said electroluminescent elements being formed by sequentially laying a transparent electrode, an electroluminescent layer and a reflector electrode on said transparent substrate;

transparent members having a profile of a frustum of pyramid or cone and respectively covering said electroluminescent elements; and

reflection films formed respectively on surfaces of said transparent members.

2. A display device according to claim 1, further comprising:

a plurality of drive elements arranged to drive the respective corresponding electroluminescent elements to emit light,

said drive element being coated respectively with said transparent members.

3. A display device according to claim 2, further comprising:

an insulating body filling gaps separating said transparent members and wires formed on said insulating body;

said drive elements being connected respectively to said wires.

4. A display device according to claim 1, further comprising:

an insulating body filling gaps separating said transparent members, and wires formed on said insulating body;

said reflector electrodes and said transparent electrodes of said electroluminescent elements being connected respectively to said wires.

5. A display device according to claim 1, wherein

each of said electroluminescent elements comprises a half mirror arranged between said transparent substrate and said transparent electrode, with

a light path length between said half mirror and said reflector electrode being integer times of ½

of a wavelength of light emitted from said electroluminescent element.

6. A display device according to claim 5, wherein

the light path length between said half mirror and said reflector electrode is equal to the wavelength of light emitted from said electroluminescent element.

7. A display device according to claim 1, wherein

each of said electroluminescent elements further comprises a light absorbing layer arranged between said reflector electrode and said electroluminescent layer and having a refractive index lower than that of said electroluminescent layer.

8. A display device according to claim 7, wherein

said electroluminescent layer of each of said electroluminescent elements includes an electron transport layer arranged at a side of said reflector electrode, and the refractive index of said light absorbing layer is lower than that of said electron transparent layer.

9. A display device according to claim 1, wherein

each of said electroluminescent elements further comprises a silica aerogel film layer arranged between said transparent substrate and said transparent electrode.

10. A display device according to claim 1, wherein

each of said electroluminescent elements has an air gap formed between said transparent substrate and said transparent electrode.

11. A display device comprising:

a transparent substrate;

a plurality of electroluminescent elements arranged on said transparent substrate, each of said electroluminescent elements being formed by sequentially laying a transparent electrode, an electroluminescent layer and a reflector electrode on said transparent substrate;

transparent members respectively covering said electroluminescent elements, each of said transparent members partly having a curved surface showing a positive curvature, a part thereof held in contact with said transparent substrate having a curved surface showing a negative curvature; and

reflection films formed respectively on surfaces of said transparent members.

12. A display device according to claim 11, wherein

each of said reflection film operates as a concave mirror relative to the corresponding electroluminescent element, and a focal plane of the concave mirror is located within said electroluminescent element.

13. A display device according to claim 11, further comprising:

a plurality of drive elements arranged to drive the respective corresponding electroluminescent elements to emit light, with

said drive elements being coated respectively with said transparent members.

14. A display device according to claim 13, further comprising:

an insulating body filling gaps separating said transparent members, and wires formed on said insulating body;

said drive elements being connected respectively to said wires.

15. A display device according to claim 11, further comprising:

an insulating body filling gaps separating said transparent members, and wires formed on said insulating body;

said reflector electrodes and said transparent electrodes of said electroluminescent elements being connected respectively to said wires.

16. A display device according to claim 11, wherein

each of said electroluminescent elements comprises a half mirror arranged between said transparent substrate and said transparent electrode, with

a light path length between said half mirror and said reflector electrode being integer times of ½

of a wavelength of light emitted from said electroluminescent element.

17. A display device according to claim 16, wherein

the light path length between said half mirror and said reflector electrode is equal to the wavelength of light emitted from said electroluminescent element.

18. A display device according to claim 11, wherein

each of said electroluminescent elements further comprises a light absorbing layer arranged between said reflector electrode and said electroluminescent layer and having a refractive index lower than that of said electroluminescent layer.

19. A display device according to claim 18, wherein

said electroluminescent layer of each of said electroluminescent elements includes an electron transport layer arranged at a side of said reflector electrode, and the refractive index of said light absorbing layer is lower than that of said electron transparent layer.

20. A display device according to claim 11, wherein

each of said electroluminescent elements further comprises a silica aerogel film layer arranged between said transparent substrate and said transparent electrode.

21. A display device according to claim 11, wherein

each of said electroluminescent elements has an air gap formed between said transparent substrate and said transparent electrode.