Display device having a light emitting element

• US 6,437,840 B1
• Filed: 10/31/2000
• Issued: 08/20/2002
• Est. Priority Date: 06/09/1997
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Miyazawa, Eiichi, Chiba, Satoshi, Arikawa, Yasuo
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): NGO, HUYEN LE
• Application Number:
  US09/699,470
• Time in Patent Office: 658 Days
• Field of Search: 349/62-65, 349/69, 349/96, 349/98, 349/113, 349/114, 349/105, 359/487, 368/84
• US Class Current: 349/62
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 5/305 including organic materials, e.g. polymeric layers
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133545 Dielectric stack polarisers
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G04G 9/0047 electrical, e.g. selection or application of the operating voltage

Abstract

A display device and an electronic timepiece displays information, such as numerical information, and the background has a glossy silver metallic tone, to give the display a quality appearance. The display device and the electronic timepiece includes a polarizer, a liquid crystal panel, and a polarization separating film. The polarization separating film transmits linearly polarized light oriented in a certain direction and reflects all other linearly polarized light. The surface of the polarization separating film which opposes the liquid crystal panel, is formed into a smooth surface which specularly reflects light, and a light-scattering layer is not provided therebetween. Light, reflected from the polarization separating film, is used to produce a glossy silver background color or information display with a metallic tone in order to give the display a quality appearance.

Claims

1. A display device, comprising a lamination in order of:

a first polarizer that transmits linearly polarized light in a first direction, and that does not transmit linearly polarized light polarized in a second direction perpendicular to a said first direction;

a liquid crystal layer that rotates a polarization direction in an on state;

a second polarizer which transmits linearly polarized light polarized in a third direction, and that reflects, in specular reflection, linearly polarized light polarized in a fourth direction perpendicular to said third direction;

a first optical element;

a reflective layer; and

a light emitting element.

2. The display device according to claim 1, said reflective layer irregularly reflecting light traveling from said second polarizer to said light emitting element.

3. The display device according to claim 2, said first optical element being a light absorbing layer.

4. The display device according to claim 3, further comprising a second optical element provided between said liquid crystal layer and said second polarizer.

5. The display device according to claim 4, said second optical element being one of a light diffusion layer and a light scattering layer.

6. The display device according to claim 5, said light absorbing layer being a tracing paper.

7. The display device according to claim 6, said light emitting element comprising an electroluminescence element.

8. The display device according to claim 3, said light absorbing layer having a visible light transmittance within a range of 40% to 80%.

9. The display device according to claim 8, said light absorbing layer having a visible light tranmittance within a range of 55% to 65%.

10. The display device according to claim 9, said light emitting element comprising a light emitting diode.

11. The display device according to claim 2, said first optical element being a coloration layer.

12. The display device according to claim 11, further comprising a second optical element provided between said liquid crystal layer and said second polarizer.

13. The display device according to claim 12, said second optical element being one of a light diffusion and a light scattering layer.

14. The display device according to claim 13, said light emitting element comprising an electroluminescence element.

15. The display device according to claim 11, said light emitting element comprising an electroluminescence element.

16. The display device according to claim 1, said light emitting element comprising one of an electroluminescence element and a light emitting diode, and emitting light of at least one of orange light and green light to said liquid crystal layer, via said second polarizer.

17. The display device according to claim 1, said liquid crystal layer being one of Twisted Nematic, Super-Twisted Nematic, Electrically Controlled Birefringence and Film Compensated Super-Nematic.