Liquid crystal display viewable under all lighting conditions

• US 20050018106A1
• Filed: 07/28/2004
• Published: 01/27/2005
• Est. Priority Date: 02/18/2003
• Status: Abandoned Application

• Current Assignee: Min-Shine C. Wang, Ran-Hong Raymond Wang
• Original Assignee: Min-Shine C. Wang, Ran-Hong Raymond Wang
• Inventors: Wang, Min-Shine C., Wang, Ran-Hong Raymond
• Application Number:
  US10/900,565
• Publication Number:
  US 20050018106A1
• Time in Patent Office: Days
• US Class Current: 349/96
• CPC Class Codes: G02F 1/133502 Antiglare, refractive index matching layers
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133555 Transflectors

Abstract

A liquid crystal display (LCD) viewable under all lighting conditions without excessive power consumption is described. The LCD comprises a first dichroic polarizer, a second dichroic polarizer, an anti-reflection layer positioned in front of the first dichroic polarizer and a liquid crystal cell positioned between the first dichroic polarizer and the second dichroic polarizer. In addition, the LCD comprises a backlight assembly positioned behind the second dichroic polarizer. Finally, the LCD comprises a diffusing transflector positioned between the backlight assembly and the second dichroic polarizer. The diffusing transflector comprises a diffusing element and a transflective element.

Claims

1. A liquid crystal display comprising:

(a) a first dichroic polarizer having a front side and a rear side;

(b) a second dichroic polarizer;

(c) an anti-reflection layer positioned in front of the first dichroic polarizer;

(d) a liquid crystal cell positioned between the first dichroic polarizer and the second dichroic polarizer;

(e) a backlight assembly positioned behind the second dichroic polarizer; and

(f) a diffusing transflector positioned between the backlight assembly and the second dichroic polarizer, the diffusing transflector comprising a diffusing element and a transflective element.

2. The liquid crystal display of claim 1 wherein the anti-reflection layer has reflection energy less than 1% over a visible spectrum range.

3. The liquid crystal display of claim 1 wherein the anti-reflection layer is a high efficiency multi-layer coating applied directly on the front side of the first dichroic polarizer.

4. The liquid crystal display of claim 3 wherein the front side of the first dichroic polarizer has a haze value less than 15%.

5. The liquid crystal display of claim 1 wherein the anti-reflection layer is a separate glass or plastic transmissive substrate with a first side of haze less than 15% and a second side, the first side having a high efficiency multi-layer anti-reflection coating, and the second side adhered to a front side of the first dichroic polarizer.

6. The liquid crystal display of claim 1 wherein the diffusing element is a transmissive substrate having a corrugated surface with a haze value of 10% to 85%.

7. The liquid crystal display of claim 6 wherein the transmissive substrate is one single sheet or multiple sheets loosely packed or bonded together, the material of the transmissive substrate being glass, PEN (polyethylene naphthalate), PC (polycarbonate), or PET (polyethylene terephthalate).

8. The liquid crystal display of claim 7 wherein the corrugated surface of the transmissive substrate is a roughened surface.

9. The liquid crystal display of claim 7 wherein the corrugated surface is a deposited layer of a dielectric material on a front surface or a rear surface of the transmissive substrate.

10. The liquid crystal display of claim 9 wherein the dielectric material is TiO2 (Titanium dioxide), Ta2O5 (Tantalum oxide), SiO2 (Silicon dioxide), SiN (Silicon nitride), ITO (Indium tin oxide), ZnS. (Zinc sulphide), Al₂O₃ (Aluminum oxide), LaF3 (Lanthanum fluoride), MgF2 (Magnesium fluoride), Ge (Germanium), or Si (Silicon).

11. The liquid crystal display of claim 7 wherein the corrugated surface is a deposited multi-layered structure of a dielectric material on a front surface or a rear surface of the transmissive substrate.

12. The liquid crystal display of claim 11 wherein the dielectric material includes at least one of TiO2 (Titanium dioxide), Ta2O5 (Tantalum oxide), SiO2 (Silicon dioxide), SiN (Silicon nitride), ITO (Indium tin oxide), ZnS (Zinc sulphide), Al₂O₃ (Aluminum oxide), LaF3 (Lanthanum fluoride), MgF2 (Magnesium fluoride), Ge (Germanium), and Si (Silicon).

13. The liquid crystal display of claim 7 wherein particles of a metal, ranging in size from 10 nm to 10000 nm, are deposited on the transmissive substrate to form the corrugated surface, the metal being silver, gold, aluminium, copper, titanium, tantalum, chromium, nickel or an alloy thereof.

14. The liquid crystal display of claim 6 wherein the transmissive substrate is bonded to a rear side of the second dichroic polarizer.

15. The liquid crystal display of claim 6 wherein the transmissive substrate is bonded to a front side of the transflective element.

16. The liquid crystal display of claim 7 wherein the transmissive substrate is bonded to a rear side of the second dichroic polarizer and a front side of the transflective element.

17. The liquid crystal display of claim 1, wherein the diffusing element is a corrugated surface with a haze value of 10% to 85%, of the second dichroic polarizer or of the transflective element.

18. The liquid crystal display of claim 17 wherein the corrugated surface is a roughened rear surface or a roughen front surface of the second dichroic polarizer or a roughened front surface of the transflective element.

19. The liquid crystal display of claim 17 wherein the corrugated surface is a deposited layer of a dielectric material on a rear surface or a front surface of the second dichroic polarizer or a front surface of the transflective element.

20. The liquid crystal display of claim 19 wherein the dielectric material is TiO2 (Titanium dioxide), Ta2O5 (Tantalum oxide), SiO2 (Silicon dioxide), SiN (Silicon nitride), ITO (Indium tin oxide), ZnS (Zinc sulphide), Al₂O₃ (Aluminum oxide), LaF3 (Lanthanum fluoride), MgF2 (Magnesium fluoride), Ge (Germanium), or Si (Silicon).

21. The liquid crystal display of claim 17 wherein the corrugated surface is a deposited multi-layered structure of a dielectric material on a rear surface or a front surface of the second dichroic polarizer or a front surface of the transflective element.

22. The liquid crystal display of claim 21 wherein the dielectric material includes at least one of TiO2 (Titanium dioxide), Ta2O5 (Tantalum oxide), SiO2 (Silicon dioxide), SiN (Silicon nitride), ITO (Indium tin oxide), ZnS (Zinc sulphide), Al₂O₃ (Aluminum oxide), LaF3 (Lanthanum fluoride), MgF2 (Magnesium fluoride), Ge (Germanium), and Si (Silicon).

23. The liquid crystal display of claim 17 wherein particles of a metal, ranging in size from 10 nm to 10000 nm, are deposited on a rear side or the front side of the second dichroic polarizer or a front side of the transflective element to form the corrugated surface, the metal being silver, gold, aluminium, copper, titanium, tantalum, chromium, nickel or an alloy thereof.

24. The liquid crystal display of claim 1 wherein the transflective element is a selective reflective polarizer, multiple sheets of selective reflective polarizers, or a diffuser laminated selective reflective polarizer, the transflective element having an extinction coefficient of 1.5 to 9 and an absorption of incident energy value less than 10%.

25. The liquid crystal display of claim 1 wherein a transmission direction of the transflective element and a transmission direction of the second dichroic polarizer form an angle of 0 degrees, between 0 and 60 degrees or between −

60 and 0 degrees for optimal transmission and reflection.

26. The liquid crystal display of claim 1 wherein the transflective element is a multi-layer dielectric material coating beam splitter with a transmission of 30% to 85%, the multi-layer dielectric material coating beam splitter being either applied directly on a rear side of the diffusing element or on a front side of a separate transmissive substrate.

27. The liquid crystal display of claim 1 wherein a second anti-reflection layer is applied on a rear side of the second dichroic polarizer.

28. The liquid crystal display of claim 27 wherein the second anti-reflection layer is on the rear side of a separate transmissive substrate with a first side and a second side, the second side having a high efficiency multi-layer anti-reflection coating, and the first side adhered to a rear side of the second dichroic polarizer.

29. The liquid crystal display of claim 1 wherein the backlight assembly comprises 1 to 12 lamps and multiple polymeric films having enhanced light transmission and optical performances, the lamps being edged or back-sided, and the polymeric film being brightness enhancement film and diffuser.

30. The liquid crystal display of claim 1 wherein the first dichroic polarizer has a first transmission direction and the second dichroic polarizer has a second transmission direction, the first transmission direction forming an angle of 0 degrees, or between 0 and 90 degrees, relative to the second transmission direction.

31. The liquid crystal display of claim 1 further comprising a quarter wave plate positioned between the liquid crystal cell and the second dichroic polarizer, the quarter wave plate generating a linear polarization from a circular polarization output of the liquid crystal cell, the linear polarization being parallel to a transmission direction of the second dichroic polarizer.

32. A liquid crystal display comprising:

(a) a first dichroic polarizer with a first transmission direction;

(b) a second dichroic polarizer with a second transmission direction, the second transmission direction forming an angle between 0 and 90 degrees relative to the first transmission direction;

(c) an anti-reflection layer positioned in front of the first dichroic polarizer with reflection energy less than 1% and a surface with a haze value less than 15%;

(d) a liquid crystal cell positioned between the first dichroic polarizer and the second dichroic polarizer;

(e) a backlight assembly positioned behind the second dichroic polarizer, the backlight assembly having 1 to 12 lamps and multiple polymeric films enhancing light transmission and optical performances, the lamps being edged or back-sided; and

(f) a diffusing transflector positioned between the backlight assembly and the second dichroic polarizer, the diffusing transflector comprising a diffusing element and a transflective element, the diffusing element having a corrugated surface with a haze value of 10% to 85%, and the transflective element being either a selective reflective polarizer with an extinction coefficient of 1.5 to 9 and an absorption of incident energy value less than 10%, or a beam splitter with a transmission value of 30% to 85%.

33. A liquid crystal display comprising:

(a) a first dichroic polarizer with a first transmission direction;

(b) a second dichroic polarizer with a second transmission direction, the second transmission direction forming an angle between 0 and 90 degrees relative to the first transmission direction;

(c) an anti-reflection layer positioned in front of the first dichroic polarizer with reflection energy less than 1% and a surface with a haze value less than 15%;

(d) a liquid crystal cell positioned between the first dichroic polarizer and the second dichroic polarizer;

(e) a backlight assembly positioned behind the second dichroic polarizer, the backlight assembly having 1 to 12 lamps and multiple polymeric films enhancing light transmission and optical performances, the lamps being edged or back-sided; and

(f) a diffusing transflector positioned between the liquid crystal cell and the second dichroic polarizer, the diffusing transflector comprising a diffusing element and a transflective element, the diffusing element having a corrugated surface with a haze value of 10% to 85%, and the transflective element being a beam splitter with a transmission value of 30% to 85%.