Liquid crystal display

• US 20060164574A1
• Filed: 12/09/2005
• Published: 07/27/2006
• Est. Priority Date: 01/26/2005
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Sang-Hoon, Yun, Young-Nam, Lee, Maung-Hi
• Granted Patent: US 7,619,703 B2
• Time in Patent Office: Days
• US Class Current: 349/113
• CPC Class Codes: G02F 1/133342 for double-sided displays
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side

Abstract

A liquid crystal display includes a backlight unit including a light source, a first panel unit disposed on a first side of the backlight unit, a second panel unit disposed on a second side of the backlight unit, and a porous reflector disposed between the backlight unit and the second panel unit and reflecting some light that is from the light source or is externally incident, and transmitting some.

Claims

1. A liquid crystal display comprising:

a backlight unit including a light source;

a first panel unit disposed on a first side of the backlight unit;

a second panel unit disposed on a second side of the backlight unit; and

a porous reflector disposed between the backlight unit and the second panel unit, the porous reflector reflecting some light and transmitting some light.

2. The liquid crystal display of claim 1, wherein the porous reflector has so low a density of reflective material that it reflects some of the light and transmits some of the light.

3. The liquid crystal display of claim 1, wherein the porous reflector is formed by patterning a photoresist provided on a reflective plate.

4. The liquid crystal display of claim 1, further comprising:

a first lower polarizer disposed between the first panel unit and the backlight unit and disposed under the first panel unit;

a first upper polarizer disposed opposite to the first lower polarizer; and

a diffusion member disposed on one side of the first lower polarizer.

5. The liquid crystal display of claim 4, further comprising:

an optical sheet disposed between the first lower polarizer and the backlight unit.

6. The liquid crystal display of claim 4, wherein the first lower polarizer comprises:

a first polarizing film facing the backlight unit, and reflecting some of the light and transmitting some of the light; and

a second polarizing film that polarizes the transmitted light.

7. The liquid crystal display of claim 6, wherein the first polarizing film and the second polarizing film are made as one film.

8. The liquid crystal display of claim 4, wherein the diffusion member comprises an adhesive including a scattering material.

9. The liquid crystal display of claim 4, wherein the first upper polarizer comprises a third polarizing film having a surface that is processed with a low reflective material.

10. The liquid crystal display of claim 1, further comprising:

a first lower polarizer disposed between the first panel unit and the backlight unit and disposed under the first panel unit; and

a first upper polarizer disposed opposite to the first lower polarizer

wherein the first lower polarizer comprises a diffusion member including an adhesive containing a scattering material.

11. The liquid crystal display of claim 1, further comprising:

a first lower polarizer disposed between the first panel unit and the backlight unit and disposed under the first panel unit; and

a first upper polarizer disposed opposite to the first lower polarizer

wherein a low reflective layer is formed on a surface of the first lower polarizer facing the backlight unit.

12. The liquid crystal display of claim 1, wherein the first panel comprises:

thin film transistors, and transparent electrodes connected to the thin film transistors;

a first panel comprising storage electrodes for maintaining charged voltages in the transparent electrodes for a certain time; and

a second panel facing the first panel and comprising black matrices, color filters between the black matrices, and a common electrode,

wherein the storage electrodes are made of a reflective material and no color filtersare provided over the storage electrodes.

13. The liquid crystal display of claim 1, wherein a ratio of transmittance to reflectance of the porous reflector ranges from 7:

3 to 6;

4.

14. A liquid crystal display comprising:

a backlight unit having a light source;

a first panel unit disposed on a first side of the backlight unit;

a second panel unit disposed on a second side of the backlight unit; and

a reflective sheet disposed between the backlight unit and the second panel unit and reflecting some light, and transmitting some light.

15. The liquid crystal display of claim 14, wherein the transflective sheet is a thin transflective film that has such a small thickness that it both reflects and transmits light.

16. The liquid crystal display of claim 15, wherein a ratio of transmittance to reflectance of the thin transflective film ranges from 7:

3 to 6;

4.

17. A liquid crystal display comprising:

a backlight unit including a light source;

a first panel unit comprising an upper panel, a lower panel facing the upper panel, a first upper polarizer disposed on the upper panel, a first lower polarizer disposed under the lower panel, a diffusion member disposed on one side of the first lower polarizer, and a liquid crystal layer interposed between the first and second panels, retarding light passing therethrough by λ

/2, having a twisted nematic mode, and forming an angle of 90 degrees between liquid crystal adjacent to the upper panel and liquid crystal adjacent to the lower panel;

a second panel unit disposed under the first panel unit; and

a porous reflector disposed between the backlight unit and the second panel unit and reflecting some light, and transmitting some light.

18. The liquid crystal display of claim 17, wherein the second panel unit comprises an upper panel, a lower panel facing the upper panel, a first upper polarizer disposed on the upper panel, a first lower polarizer disposed under the lower panel, a diffusion member disposed on one side of the first lower polarizer, and a liquid crystal layer interposed between the first and second panels, retarding light passing therethrough by λ

/2, having a twisted nematic mode, and forming an angle of 90 degrees between liquid crystal adjacent to the upper panel and liquid crystal adjacent to the lower panel.

19. The liquid crystal display of claim 17, wherein the porous reflector has so low a density of reflective material such that it reflects some of the light and transmits some of the light.

20. The liquid crystal display of claim 17, wherein the porous reflector is formed by patterning a photoresist provided on a reflective plate.

21. The liquid crystal display of claim 17, wherein the first lower polarizer comprises:

a first polarizing film facing the backlight unit, and reflecting some of the light and transmitting some of the light; and

a second polarizing film polarizing the transmitted light.

22. The liquid crystal display of claim 21, wherein the diffusion member comprises an adhesive containing a scattering material.