Display device, electronic apparatus using the same, and light guider for display devices

• US 6,630,968 B1
• Filed: 09/25/2000
• Issued: 10/07/2003
• Est. Priority Date: 02/01/1999
• Status: Expired due to Term

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Iljima, Chiyoaki, Tsuchihashi, Toshihiko
• Primary Examiner(s): Ton, Toan
• Assistant Examiner(s): NGUYEN, HOAN C
• Application Number:
  US09/647,394
• Time in Patent Office: 1,107 Days
• Field of Search: 349/65, 349/96, 349/113, 349/119
• US Class Current: 349/65
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence

Abstract

A TN liquid crystal 140 is used as a liquid crystal panel, and a polarizer 130 is provided above the TN liquid crystal 140 while a polarizer 135, a light scattering layer 150 and a polarized light splitter 160 are provided in this order under the TN liquid crystal 140. Furthermore, under the polarized light splitter 160, there is provided a light guide 190 for introducing light of a light source 191 from under the polarized light splitter 160 and a reflecting plate 200. The polarized light splitter 160 is a reflecting polarizer which can accomplish the effective utilization of light so that extremely bright reflective and transmissive displays are obtainable. Additionally, since a light diffusing layer 150 is provided, even if the distance from the TN liquid crystal 140 to the reflecting plate 200 is prolonged, in the reflective display, no double image nor display bleeding occurs.

Claims

1. A display device comprising:

a first polarized light splitting plate;

a second polarized light splitting plate;

a liquid crystal panel positioned between the first and second polarized light splitting plates;

a reflecting layer positioned on the same side of said liquid crystal panel as said second polarized light splitting plate, said second polarized light splitting plate being positioned between said liquid crystal panel and said reflecting layer;

a light guider positioned between said second polarized light splitting plate and said reflecting layer;

a third polarized light splitting plate positioned between said second polarized light splitting plate and said light guider, said third polarized light splitting plate transmitting or reflecting light in accordance with a polarization component of the light; and

a forward scattering plate positioned between said second polarized light splitting plate and said third polarized light splitting plate such that light incident upon said liquid crystal panel passes through said forward scattering plate while coming to and returning from said reflecting layer.

2. The display device of claim 1, wherein:

said second polarized light splitting plate transmits a polarized light polarized in a first direction, and

said third polarized light splitting plate transmits a polarized light polarized in said first direction, and reflects a polarized light polarized in a second direction, said second direction being different from said first direction.

3. The display device of claim 2, wherein said second polarized light splitting plate absorbs a polarized light polarized in a third direction, said third direction being different from said first direction.

4. The display device of claim 1, wherein said second polarized light splitting plate absorbs a polarized light polarized in a direction which is different from a direction that said third polarized light splitting plate transmits.

5. The display device according to claim 1, wherein said forward scattering plate is positioned between said liquid crystal panel and said light guider.

6. The display device according to claim 1, wherein an optical anisotropy in said light guider minimally influences display chrominance non-uniformity in said display device.

7.The display device according to claim 1, wherein said light guider includes substantially constant optical axes directions.

7. The display device according to claim 1, wherein said third polarized light splitting plate includes adjacent layers, refractive indexes of the said adjacent layers being substantially equal in a predetermined direction while being different from each other in another direction that is perpendicular to said predetermined direction.

8. The display device according to claim 1, wherein said liquid crystal display panel comprises at least one of a TN liquid crystal element, a STN liquid crystal element, and an ECB liquid crystal element.

9. The display device according to claim 1, further comprising coloring means positioned between said first polarized light splitting plate and said light guider.

11. An electronic apparatus incorporating said display device according to claim 1.

10. The display device according to claim 10, wherein said coloring means include a plurality of colors.

12. A display device comprising:

a liquid crystal panel;

a polarizer positioned on one side of said liquid crystal display, said polarizer having a polarization axis for transmitting a polarized light;

a reflector positioned on the same side of said liquid crystal panel as said polarized light splitting plate so that said polarizer is located between said liquid crystal panel and said reflector;

a light guider positioned between said polarized light splitting plate and said reflector;

a polarized light splitting plate positioned between said light guider and said polarizer, said polarized, light splitting plate having a polarization axis for transmitting polarized light, the polarization axes of said polarizer and said polarized light splitting plate forming an angle between 0° and

40°

; and

a forward scattering plate positioned between said polarizer and said polarized light splitting plate such that light incident upon said liquid crystal panel passes through said forward scattering plate while coming to and returning from said reflector.

13. The display device according to claim 13, wherein said forward scattering plate is positioned between said liquid crystal panel and said light guider.

14. The display device according to claim 13, wherein said polarized light splitting plate includes adjacent layers, refractive indexes of the adjacent layers being substantially equal in a predetermined direction while being different from each other in another direction that is perpendicular to said predetermined direction.

15. The display device according to claim 13, wherein said liquid crystal display panel comprises at least one of a TN liquid crystal element, a STN liquid crystal element, and an ECB liquid crystal element.

16. The display device according to claim 13, further comprising coloring means including a plurality of colors.

17. An electronic apparatus incorporating said display device according to claim 13.

18. A display device comprising:

a first polarized light splitting plate;

a second polarized light splitting plate;

a liquid crystal panel positioned between the first and second polarized light splitting plates;

a reflecting layer positioned on the same side of said liquid crystal panel as said second polarized light splitting plate, said second polarized light splitting plate being positioned between said liquid crystal panel and said reflecting layer;

a light guider positioned between said second polarized light splitting plate and said reflecting layer;

a third polarized light splitting plate positioned between said second polarized light splitting plate and said light guider, said third polarized light splitting plate transmitting or reflecting light in accordance with a polarization component of the light; and

a forward scattering plate positioned between said second polarized light splitting plate and said third polarized light splitting plate for scattering forwardly both light from said reflecting layer side toward said liquid crystal panel side and light from said liquid crystal panel side toward said reflecting layer side.