WIRE GRID POLARIZED AND LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME

• US 20080094547A1
• Filed: 10/19/2007
• Published: 04/24/2008
• Est. Priority Date: 10/20/2006
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Japan Display East Incorporated (Japan Display Incorporated)
• Inventors: Hirota, Shoichi, Sugita, Tatsuya
• Granted Patent: US 8,049,841 B2
• Time in Patent Office: Days
• US Class Current: 349/96
• CPC Class Codes: G02B 5/3058 comprising electrically conductive elements, e.g. wire grids, conductive particles
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133548 Wire-grid polarisers
• CPC Class Codes: G02F 1/133565 inside the LC elements, i.e. between the cell substrates

Abstract

An image is displayed by modulating TM-polarized light between the polarizer 2 and the wire grid polarizer 18 through the variation of the optical characteristic of the liquid crystal layer 12 interposed between the transparent plate 4 and the transparent plate 26. Degradation of contrast in the bright ambience is avoided by providing an absorption layer for absorbing TE-polarized light on that surface of the wire grid polarizer 18 which faces the liquid crystal layer 12.

Claims

1. A liquid crystal display device comprising:

a first transparent plate having a first polarizer;

a second transparent plate having a second polarizer and disposed opposite to the first transparent plate;

a liquid crystal layer hermetically sealed and interposed between the first transparent plate and the second transparent plate, for constituting plural pixels;

a first and a second electrodes for driving the liquid crystal layer;

light transmission sections, each being formed corresponding to at least a part of the pixel;

wherein the first polarizer is a wire grid polarizer, and a light absorbing layer for absorbing TE-polarized light provided on that surface of the wire grid polarizer which faces the liquid crystal layer.

2. A liquid crystal display device as claimed in claim 1, wherein the wire grid polarizer is used as the first electrode.

3. A liquid crystal display device as claimed in claim 2, wherein the first electrode is used as a common electrode, the second electrode is used as a pixel electrode, and the first electrode and the second electrode with an insulation layer interposed between them are disposed on the first transparent plate.

4. A liquid crystal display device as claimed in claim 2, wherein a layer of transparent conductive material or metal is provided on the other surface of the wire grid polarizer.

5. A liquid crystal display device as claimed in claim 2, wherein the first electrode is used as a pixel electrode, the second electrode is used as a common electrode, and the first electrode is electrically connected with a switching element, thereby potential difference being developed between the switching element and the second electrode.

6. A liquid crystal display device as claimed in claim 1, wherein the wire grid polarizer, the first electrode and the second electrode are arranged in this order mentioned.

7. A liquid crystal display device as claimed in claim 1, further comprising a reflection display section for making display by changing reflectivity by means of the liquid crystal layer driven by the potential difference between the first and the second electrode, wherein the reflection display section operates as reflection display by reflecting the external light transmitted through the first polarizer.

8. A liquid crystal display device as claimed in claim 7, wherein the reflection display section has a reflective layer for reflecting the light transmitted through the first polarizer, and the reflective layer is provided on the opposite side of the first polarizer to the light absorbing layer.

9. A liquid crystal display device as claimed in claim 8, wherein the reflective layer has a wavy surface.

10. A liquid crystal display device as claimed in claim 1, wherein the second polarizer is a wire grid polarizer.

13. A liquid crystal display device as claimed in claim 1, further comprising a planar light emitting element, wherein a lens array is provided between the planar light emitting element and the first transparent plate.

11. A liquid crystal display device comprising:

a first transparent plate having a first polarizer;

a second transparent plate having a second polarizer and disposed opposite to the first transparent plate;

a liquid crystal layer hermetically sealed and interposed between the first transparent plate and the second transparent plate, for constituting plural pixels;

a first and a second electrodes for driving the liquid crystal layer; and

light transmission sections, each being formed corresponding to at least a part of the pixel,

wherein the first polarizer is provided on the side of the liquid crystal layer; and

the first polarizer absorbs the TE-polarized light impinging thereon from the side of the liquid crystal layer and reflects the TE-polarized light impinging thereon from the opposite side.

12. A liquid crystal display device as claimed in claim 11, further comprising a reflection display section for making display by changing reflectivity by means of the liquid crystal layer driven by the potential difference between the first and the second electrodes, wherein the reflection display section makes reflection display by reflecting the external light transmitted through the first polarizer.

14. A wire grid polarizer comprising fine metal wires arranged parallel to one another and thus transmitting TM-polarized light, wherein a light absorbing layer for absorbing TE-polarized light is provided on at least one of the surfaces of the wire grid polarizer.

15. A wire grid polarizer as claimed in claim 14, wherein the light absorbing layer consists of composite fine lines, each fine line being a lamination of dielectric material and metal and stacked on each fine metal wire of the wire grid polarizer.

16. A wire grid polarizer as claimed in claim 15, wherein the refractivity of the dielectric material is not less than 1.8 for the visible spectrum of light.

17. A wire grid polarizer as claimed in claim 15, wherein the metal of the lamination has a real part of complex refractive index of not less than unity and an extinction coefficient of not less than unity.

18. A wire grid polarizer as claimed in claim 14, wherein the light absorbing layer is a polarizer layer of coating type.

19. A wire grid polarizer as claimed in claim 18, wherein the polarizer layer of coating type is formed on the fine metal wires of the wire grid polarizer.

20. A wire grid polarizer as claimed in claim 14, wherein a light reflection layer is provided on the opposite side of the wire grid polarizer to the surface on which the light absorbing layer is disposed, the reflection layer reflecting TM-polarized light transmitted through the wire grid polarizer.