Liquid crystal display viewable under all lighting conditions

• US 6,961,108 B2
• Filed: 07/16/2004
• Issued: 11/01/2005
• Est. Priority Date: 02/18/2003
• Status: Expired due to Fees

• Current Assignee: Min-Shine C. Wang, Ran-Hong Raymond Wang
• Original Assignee: Min-Shine C. Wang, Ran-Hong Raymond Wang
• Inventors: Wang, Ran-Hong Raymond, Wang, Min-Shine C.
• Primary Examiner(s): Dudek, James A.
• Application Number:
  US10/892,867
• Publication Number:
  US 20040263720A1
• Time in Patent Office: 473 Days
• Field of Search: 349/114, 349/137
• US Class Current: 349/137
• 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 method of making an LCD viewable under all lighting condition from an LCD having a liquid crystal cell positioned between a first dichroic polarizer and a second dichroic polarizer, and a backlight assembly positioned behind the second dichroic polarizer, the method comprising the steps of:

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

(b) positioning a diffusing transflector between the backlight assembly and the second dichroic polarizer, the diffusing transflector comprising a diffusing element and a reflective polarizer, the diffusing element being a transparent substrate layer or a corrugated surface having a haze value of 10% to 85%, and the reflective polarizer being positioned with its transmission direction forming an angle of 0 degree, between 0 and 60 degrees, or between −

60 and 0 degrees to the transmission direction of the second dichroic polarizer.

2. A method of making an LCD viewable under all lighting condition from an LCD having a liquid crystal cell positioned between a first dichroic polarizer and a second dichroic polarizer, a backlight assembly positioned behind the second dichroic polarizer, and a reflective polarizer positioned between the backlight assembly and the second dichroic polarizer with its transmission direction forming an angle of 0 degree, between 0 and 60 degrees, or between −

60 and 0 degrees to the transmission direction of the second dichroic polarizer, the method comprising the steps of;

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

(b) positioning a diffusing element between the second dichroic polarizer and the reflective polarizer, the diffusing element being a transparent substrate layer or a corrugated surface having a haze value of 10% to 85%.

3. A method of making an LCD viewable under all lighting condition from an LCD having a liquid crystal cell positioned between a first dichroic polarizer and a second dichroic polarizer, a backlight assembly positioned behind the second dichroic polarizer, and a diffusing transflector positioned between the backlight assembly and the second dichroic polarizer, the diffusing transflector comprising a diffusing element and a reflective polarizer, the diffusing element being a transparent substrate layer or a corrugated surface having a haze value of 10% to 85%, and the reflective polarizer having its transmission direction forming an angle of 0 degree, between 0 and 60 degrees, or between −

60 and 0 degrees to the transmission direction of the second dichroic polarizer, the method comprising the step of positioning an anti-reflection layer with a surface of haze value less than 15% in front of the first dichroic polarizer.

4. A method of making an LCD viewable under all lighting condition from an LCD having a liquid crystal cell positioned between a first dichroic polarizer with anti-reflection treatment and surface haze less than 15% and a second dichroic polarizer, a backlight assembly positioned behind the second dichroic polarizer, the method comprising the step of:

positioning a diffusing transflector between the backlight assembly and the second dichroic polarizer, the diffusing transflector comprising a diffusing element and a reflective polarizer, the diffusing element being a transparent substrate layer or a corrugated surface having a haze value of 10% to 85%, and the reflective polarizer being positioned with its transmission direction forming an angle of 0 degree, between 0 and 60 degrees, or between −

60 and 0 degrees to the transmission direction of the second dichroic polarizer.

5. A method of making an LCD viewable under all lighting condition from an LCD having a liquid crystal cell positioned between a first dichroic polarizer and a second dichroic polarizer, a backlight assembly positioned behind the second dichroic, polarizer, and a diffusing element being a transparent substrate layer or a corrugated surface having a haze value of 10% to 85% in front of the backlight assembly, the method comprising the steps of:

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

(b) positioning a transflector between the backlight assembly and the diffusing element, the transflector being a reflective polarizer positioned such that its transmission direction forms an angle of 0 degree, between 0 and 60 degrees, or between −

60 and 0 degrees to the transmission direction of the second dichroic polarizer.

6. A method of making an LCD viewable under all lighting condition from an LCD having a liquid crystal cell positioned between a first dichroic polarizer with anti-reflection treatment and surface haze less than 15% and a second dichroic polarizer, a backlight assembly positioned behind the second dichroic polarizer, and a reflective polarizer positioned between the second dichroic polarizer and the backlight assembly with its transmission direction forming an angle of 0 degree, between 0 and 60 degrees, or between −

60 and 0 degrees to the transmission direction of the second dichroic polarizer, the method comprising the step of;

positioning a diffusing element between the second dichroic polarizer and the reflective polarizer, the diffusing element being a transparent substrate layer or a corrugated surface having a haze value of 10% to 85%.