EP0622656A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical compensator for liquid crystal display
Assignee: Boeing North American Inc
•
Filing: 1994-04-29
•
Granted: —
•
Expires: 2014-04-29
Abstract
Abstract A normally white liquid crystal display includes polarizer and analyzer layers having perpendicular absorbing axes. A liquid crystal layer is disposed between the polarizer layer and the analyzer layer, with its director exhibiting an azimuthal twist through the layer. First and second electrodes are proximate to first and second major surfaces of the liquid crystal layer. A first negatively birefringent compensator layer, oriented with its optical axis substantially parallel to the average direction of the optical axis within a central, nominally homeotropic region of the liquid crystal layer in its driven state, is disposed between the polarizer layer and the liquid crystal layer. A second negatively birefringent compensator layer, with a birefringence substantially the same as the birefringence of the first compensator layer and oriented with its optical axis substantially parallel to the optical axis of the first compensator layer, is disposed between the analyzer layer and the liquid crystal layer.
Inventors
- 👤 Bruce K. Winker
- 👤 William J. Gunning Iii
- 👤 Donald B. Taber
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 00:04
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/13363; G02F1/133632; G02F1/137; G02F1/139; G02F1/1396; G02F1/1397; G02F2413/00; G02F2413/14
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
156 words
A normally white liquid crystal display, comprising: a polarizer layer having an absorbing axis; an analyzer layer having an absorbing axis substantially perpendicular to the absorbing axis of the polarizer layer; a liquid crystal layer disposed between the polarizer layer and the analyzer layer and having a director exhibiting an azimuthal twist through the layer: a first electrode proximate to a first major surface of the liquid crystal layer; a second electrode proximate to a second major surface of the liquid crystal layer, the first and second electrodes being adapted to apply a voltage across the liquid crystal layer when the electrodes are connected to a source of electrical potential; and a first negatively birefringent compensator layer, oriented with its optical axis substantially parallel to the average direction of the optical axis within a central, nominally homeotropic region of the liquid crystal layer in its driven state, disposed between the polarizer layer and the analyzer layer.
Claim 2
Dependent Claim
64 words
The liquid crystal display of Claim 1, wherein the liquid crystal layer is tilted with respect to the first compensator layer, the polarizer layer, and the analyzer layer such that the optical axis of the first compensator layer is substantially parallel to the average direction of the optical axis within the central, nominally homeotropic region of the liquid crystal layer in its driven state.
Claim 3
Dependent Claim
60 words
The liquid crystal display of Claim 1, wherein the first compensator layer is tilted with respect to the polarizer, analyzer, and liquid crystal layers such that the optical axis of the first compensator layer is substantially parallel to the average direction of the optical axis within the central, nominally homeotropic region of the liquid crystal layer in its driven state.
Claim 4
Dependent Claim
49 words
The liquid crystal display of Claim 1, wherein: the absorbing axis of the polarizer layer is oriented substantially perpendicular to the extraordinary axis of the first compensator layer; and the absorbing axis of the analyzer layer is oriented substantially perpendicular to the extraordinary axis of the first compensator layer.
Claim 5
Dependent Claim
75 words
The liquid crystal display of Claim 1, wherein the first negatively birefringent compensator layer is further disposed between the polarizer layer and the analyzer layer, and further comprising a second negatively birefringent compensator layer, with a birefringence substantially the same as the birefringence of the first compensator layer and oriented with its optical axis substantially parallel to the optical axis of the first compensator layer, disposed between the analyzer layer and the liquid crystal layer.
Claim 6
Dependent Claim
29 words
The liquid crystal display of Claim 5, wherein the optical axes of the compensator layers are oriented substantially perpendicular to the first major surface of the liquid crystal layer.
Claim 7
Dependent Claim
65 words
The liquid crystal display of Claim 5, wherein the liquid crystal layer is tilted with respect to the first and second compensator layers, the polarizer layer, and the analyzer layer such that the optical axes of the compensator layers are substantially parallel to the average direction of the optical axis within the central, nominally homeotropic region of the liquid crystal layer in its driven state.
Claim 8
Dependent Claim
61 words
The liquid crystal display of Claim 5, wherein the first and second compensator layers are tilted with respect to the polarizer, analyzer, and liquid crystal layers such that the optical axes of the compensator layers are substantially parallel to the average direction of the optical axis within the central, nominally homeotropic region of the liquid crystal layer in its driven state.
Claim 9
Dependent Claim
47 words
The liquid crystal display of Claim 5, wherein: the absorbing axis of the polarizer layer is oriented substantially perpendicular to the extraordinary axes of the compensator layers; and the absorbing axis of the analyzer layer is oriented substantially perpendicular to the extraordinary axes of the compensator layers.
Claim 10
Dependent Claim
162 words
A normally white liquid crystal display of the type including a polarizer layer having an absorbing axis, an analyzer layer having an absorbing axis substantially perpendicular to the absorbing axis of the polarizer layer, a liquid crystal layer disposed between the polarizer layer and the analyzer layer and having a director exhibiting an azimuthal twist through the layer, a first electrode proximate to a first major surface of the liquid crystal layer, and a second electrode proximate to a second major surface of the liquid crystal layer, the first and second electrodes being adapted to apply a voltage across the liquid crystal layer when the electrodes are connected to a source of electrical potential; the improvement comprising: a first negatively birefringent compensator layer, oriented with its optical axis substantially parallel to the average direction of the optical axis within a central, nominally homeotropic region of the liquid crystal layer in its driven state, disposed between the polarizer layer and the analyzer layer
Claim 11
Dependent Claim
64 words
The liquid crystal display of Claim 10, wherein the liquid crystal layer is tilted with respect to the first compensator layer, the polarizer layer, and the analyzer layer such that the optical axis of the first compensator layer is substantially parallel to the average direction of the optical axis within the central, nominally homeotropic region of the liquid crystal layer in its driven state.
Claim 12
Dependent Claim
60 words
The liquid crystal display of Claim 10, wherein the first compensator layer is tilted with respect to the polarizer, analyzer, and liquid crystal layers such that the optical axis of the first compensator layer is substantially parallel to the average direction of the optical axis within the central, nominally homeotropic region of the liquid crystal layer in its driven state.
Claim 13
Dependent Claim
49 words
The liquid crystal display of Claim 10, wherein: the absorbing axis of the polarizer layer is oriented substantially perpendicular to the extraordinary axis of the first compensator layer; and the absorbing axis of the analyzer layer is oriented substantially perpendicular to the extraordinary axis of the first compensator layer.
Claim 14
Dependent Claim
75 words
The liquid crystal display of Claim 10, wherein the first negatively birefringent compensator layer is further disposed between the polarizer layer and the analyzer layer, and further comprising a second negatively birefringent compensator layer, with a birefringence substantially the same as the birefringence of the first compensator layer and oriented with its optical axis substantially parallel to the optical axis of the first compensator layer, disposed between the analyzer layer and the liquid crystal layer.
Claim 15
Dependent Claim
29 words
The liquid crystal display of Claim 14, wherein the optical axes of the compensator layers are oriented substantially perpendicular to the first major surface of the liquid crystal layer.
Claim 16
Dependent Claim
65 words
The liquid crystal display of Claim 14, wherein the liquid crystal layer is tilted with respect to the first and second compensator layers, the polarizer layer, and the analyzer layer such that the optical axes of the compensator layers are substantially parallel to the average direction of the optical axis within the central, nominally homeotropic region of the liquid crystal layer in its driven state.
Claim 17
Dependent Claim
61 words
The liquid crystal display of Claim 14, wherein the first and second compensator layers are tilted with respect to the polarizer, analyzer, and liquid crystal layers such that the optical axes of the compensator layers are substantially parallel to the average direction of the optical axis within the central, nominally homeotropic region of the liquid crystal layer in its driven state.
Claim 18
Dependent Claim
47 words
The liquid crystal display of Claim 14, wherein: the absorbing axis of the polarizer layer is oriented substantially perpendicular to the extraordinary axes of the compensator layers; and the absorbing axis of the analyzer layer is oriented substantially perpendicular to the extraordinary axes of the compensator layers.
Claim 19
Independent Claim
178 words
A method of compensating for phase retardation in a normally white liquid crystal display of the type including a polarizer layer having an absorbing axis, an analyzer layer having an absorbing axis substantially perpendicular to the absorbing axis of the polarizer layer, a liquid crystal layer disposed between the polarizer layer and the analyzer layer and having a director exhibiting an azimuthal twist through the layer, a first electrode proximate to a first major surface of the liquid crystal layer, and a second electrode proximate to a second major surface of the liquid crystal layer, the first and second electrodes being adapted to apply a voltage across the liquid crystal layer when the electrodes are connected to a source of electrical potential, the method comprising the steps of: placing a first negatively birefringent compensator layer between the polarizer layer and the analyzer layer; and orienting the first compensator layer with its optical axis substantially parallel to the average direction of the optical axis within a central, nominally homeotropic region of the liquid crystal layer in its driven state
Claim 20
Dependent Claim
65 words
The method of Claim 19, further comprising the step of: tilting the liquid crystal layer with respect to the first compensator layer, the polarizer layer, and the analyzer layer such that the optical axis of the first compensator layer is substantially parallel to the average direction of the optical axis within the central, nominally homeotropic region of the liquid crystal layer in its driven state.
Claim 21
Dependent Claim
61 words
The method of Claim 19, further comprising the step of: tilting the first compensator layer with respect to the polarizer, analyzer, and liquid crystal layers such that the optical axis of the first compensator layer is substantially parallel to the average direction of the optical axis within the central, nominally homeotropic region of the liquid crystal layer in its driven state.
Claim 22
Dependent Claim
49 words
The method of Claim 19 further comprising the steps of: orienting the absorbing axis of the polarizer layer substantially perpendicular to the extraordinary axis of the first compensator layer; and orienting the absorbing axis of the analyzer layer substantially perpendicular to the extraordinary axis of the first compensator layer.
Claim 23
Dependent Claim
93 words
The method of Claim 19, wherein the step of placing a first negatively birefringent compensator further comprises placing the first negatively birefringent compensator layer between the polarizer layer and the liquid crystal layer, and wherein the method further comprises the steps of: placing a second negatively birefringent compensator layer, with a birefringence substantially the same as the birefringence of the first compensator layer, between the analyzer layer and the liquid crystal layer; and orienting the second compensator layer with its optical axis substantially parallel to the optical axis of the first compensator layer.
Claim 24
Dependent Claim
70 words
The method of Claim 23, wherein the step of orienting the first compensator layer further comprises orienting the first compensator layer with its optical axis substantially perpendicular to the first major surface of the liquid crystal layer and wherein the step of orienting the second compensator layer further comprises orienting the second compensator layer with its optical axis substantially perpendicular to the first major surface of the liquid crystal layer.
Claim 25
Dependent Claim
66 words
The method of Claim 23, further comprising the step of: tilting the liquid crystal layer with respect to the first and second compensator layers, the polarizer layer, and the analyzer layer such that the optical axes of the compensator layers are substantially parallel to the average direction of the optical axis within the central, nominally homeotropic region of the liquid crystal layer in its driven state.
Claim 26
Dependent Claim
62 words
The method of Claim 23, further comprising the step of: tilting the first and second compensator layers with respect to the polarizer, analyzer, and liquid crystal layers such that the optical axes of the compensator layers are substantially parallel to the average direction of the optical axis within the central, nominally homeotropic region of the liquid crystal layer in its driven state.
Claim 27
Dependent Claim
47 words
The method of Claim 23, further comprising the steps of: orienting the absorbing axis of the polarizer layer substantially perpendicular to the extraordinary axes of the compensator layers; and orienting the absorbing axis of the analyzer layer substantially perpendicular to the extraordinary axes of the compensator layers.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.