Claims
- 1. A liquid crystal display comprising:
- a liquid crystal layer;
- a rear polarizer having a transmission axis;
- a front polarizer disposed on the viewer side of the liquid crystal layer so that the liquid crystal layer is disposed between the front and rear polarizers;
- first and second tilted retardation films on opposite sides of the liquid crystal layer, said first and second tilted retardation films being positively birefringent and uniaxial, and each having an optical axis tilted or at an oblique angle relative to a normal axis that is substantially perpendicular to a surface of one of said tilted retardation films;
- first and second negative retarders located on opposite sides of the liquid crystal layer, said first and second negative retarders each having an optical axis substantially parallel to the normal axis; and
- wherein said negative retarders and said tilted retardation films have retardation values and axis alignment such that the display exhibits a contrast ratio, when a 550 nm wavelength is used, of at least about 10:1 over a horizontal angular span of at least about 120.degree. and over a vertical angular span of at least about 80.degree..
- 2. The display of claim 1, wherein said front and rear polarizers are arranged relative to one another so as to define a normally white twisted nematic display.
- 3. The display of claim 2, wherein d..DELTA.n of the liquid crystal layer is from about 380-550 nm.
- 4. The display of claim 1, wherein the contrast ratio at 550 nm is at least about 40 or 40:1 at 0.degree. vertical, .+-.60.degree. horizontal.
- 5. The display of claim 1, wherein said polarizer and retardation axes are oriented relative to one another so that when gray level voltages of from about 2.25 volts to 6.5 volts are applied across the liquid crystal there are substantially no inversion humps or rises at horizontal viewing angles of from about -60.degree. to +60.degree. and at vertical viewing angles of from about 40.degree. to +40.degree..
Parent Case Info
This is a continuation of application Ser. No. 08/383,200, filed Feb. 3, 1995, now U.S. Pat. No. 5,638,200.
US Referenced Citations (10)
Foreign Referenced Citations (1)
Number |
Date |
Country |
06174920 |
Jun 1994 |
JPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
383200 |
Feb 1995 |
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