US 6,359,671 B1 · High contrast liquid crystal device

Abstract

A normally white twisted nematic liquid crystal display (LCD) includes a liquid crystal layer for twisting at least one normally incident wavelength of visible light when in the off-state. Front and rear orientation layers sandwich the liquid crystal layer therebetween with the front orientation layer causing a front liquid crystal tilt sense direction AF and the rear orientation layer causing a rear liquid crystal tilt sense direction AR different than the direction AF. Rear and front tilted retardation layers are located on opposite sides of said liquid crystal layer. Each of the rear and front tilted retardation layers has an optical axis defining an azimuthal angle φ, and a tilt angle θ, where at least the tilt angle θ varies through the thickness of the layer. The azimuthal angle aspect φ of an optical axis of the rear tilted retardation layer is oriented substantially anti-parallel relative to the rear tilt sense direction AR of liquid crystal molecules proximate the rear orientation layer, and the azimuthal angle aspect φ of an optical axis of the front tilted retardation layer is oriented substantially parallel relative to the front tilt sense direction AF of liquid crystal molecules proximate the front orientation layer. At least one of the rear and front tilted retardation layers includes a tilt angle θ which is substantially greater on the side of the tilted retardation layer closest to the liquid crystal layer than on the side furthest from the liquid crystal layer.

Claims66

Dependent claims

A normally white twisted nematic liquid crystal display (LCD) comprising:

(a) a liquid crystal layer for twisting at least one normally incident wavelength of visible light when in the off-state;
(b) first and second orientation layers sandwiching said liquid crystal layer therebetween, said first orientation layer causing a first liquid crystal tilt sense direction AFirst and said second orientation layer causing a second liquid crystal tilt sense direction ASecond different than said direction AFirst;
(c) second and first tilted retardation layers located on opposite sides of said liquid crystal layer;
(d) each of said second and first tilted retardation layers having an optical axis defining at least one azimuthal angle φ, and at least one tilt angle θ, where at least said tilt angle θ varies through the thickness of the layer;
(e) said azimuthal angle aspect φ of an optical axis of said second tilted retardation layer is oriented substantially anti-parallel relative to said second tilt sense direction ASecond of liquid crystal molecules proximate said second orientation layer, and said azimuthal angle aspect φ of an optical axis of said first tilted retardation layer is oriented substantially parallel relative to said first tilt sense direction AFirst liquid crystal molecules proximate said first orientation layer;
and
(f) at least one of said second and first tilted retardation layers includes a tilt angle θ which is substantially greater on the side of the tilted retardation layer closest to said liquid crystal layer than on the side furthest from said liquid crystal layer.

4 more elements

A normally white twisted nematic liquid crystal display (LCD) comprising:

(a) a liquid crystal layer for twisting at least one normally incident wavelength of visible light when in the off-state;
(b) first and second orientation layers sandwiching said liquid crystal layer therebetween, said first orientation layer causing a first liquid crystal tilt sense direction AFirst and said second orientation layer causing a second liquid crystal tilt sense direction ASecond different than said direction AFirst;
(c) second and first tilted retardation layers located on opposite sides of said liquid crystal layer;
(d) each of said second and first tilted retardation layers having an optical axis defining azimuthal angle φ and at least one tilt angle θ, where at least said tilt angle θ varies through the thickness of the layer;
and
(e) at least one of said azimuthal angle aspect φ of an optical axis of said second tilted retardation layer is oriented substantially perpendicular relative to said second tilt sense direction ASecond of liquid crystal molecules proximate said second orientation layer, and said azimuthal angle aspect φ of an optical axis of said first tilted retardation layer is oriented substantially perpendicular relative to said first tilt sense direction AFirst of liquid crystal molecules proximate said first orientation layer, wherein said second tilted retardation layer is on said side of said liquid crystal layer proximate said second orientation layer.

3 more elements

A normally white twisted nematic liquid crystal display (LCD) comprising:

(a) a liquid crystal layer for twisting at least one normally incident wavelength of visible light when in the off-state;
(b) first and second orientation layers sandwiching said liquid crystal layer therebetween, said first orientation layer causing a first liquid crystal tilt sense direction AFirst and said second orientation layer causing a second liquid crystal tilt sense direction ASecond different than said direction AFirst;
(c) first and second tilted retardation layers located on the same side of said liquid crystal layer;
(d) each of said first and second tilted retardation layers having an optical axis defining at least one azimuthal angle φ, and at least one tilt angle θ, where at least said tilt angle θ varies through the thickness of the layer;
and
(e) said at least one said azimuthal angle aspect φ of an optical axis of said first tilted retardation layer is oriented substantially anti-parallel relative to said second tilt sense direction ASecond of liquid crystal molecules proximate said second orientation layer.

3 more elements

Dependencies are inferred from the claim text.

High contrast liquid crystal device

Life of this patent

High contrast liquid crystal device

Life of this patent

Abstract

Claims66