US4834506A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Perceived contrast of liquid crystal displays
Assignee: AUO Corp
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Filing: 1987-07-02
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Granted: 1989-05-30
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Expires: 2007-07-02
Abstract
Abstract There is disclosed a technique for improving user perceived quality of an LCD device comprising optimizing the electrode width and inter-electrode spacing, and simultaneously causing inter-electrode spaces and information to appear dark while the background appears bright.
Inventors
- 👤 Kent R. Demke
- 👤 Neil D. Lubart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:13
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1343; G02F1/134309; G02F1/134336
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
133 words
A method for improving user perceived contrast quality of a liquid crystal display device comprising: locating on a substrate parallel electrodes in two sets of electrodes, for superposition relative to each other at a predetermined angular displacement, for defining at each intersection of superimposed electrodes active display elements such that within each set of parallel electrodes, inter-electrode spaces are at their optimally minimal size; and causing said inter-electrode spaces to be always dark, choosing inter-electrode spacing in accordance with the relationship ##EQU5## G V =Vertical Gap Between Conductors G H =Horizontal Gap Between Conductors V=Vertical Pitch H=Horizontal Pitch L G =Luminance of Gap (Inter-electrode space) B p =Luminance of Pel in Bright State D p =Luminance of Pel in Dark State C p =B p /D p =In-Pel Contrast C E =Effective Contrast
Claim 2
Independent Claim
133 words
A method for improving user perceived contrast quality of a liquid crystal display device comprising: locating on a substrate parallel electrodes in two sets of electrodes, for superposition relative to each other at a predetermined angular displacement, for defining at each intersection of superimposed electrodes active display elements such that within each set of parallel electrodes, inter-electrode spaces are at their optimally minimal size; and causing said inter-electrode spaces to be always dark, choosing inter-electrode spacing in accordance with the relationship ##EQU5## G V =Vertical Gap Between Conductors G H =Horizontal Gap Between Conductors V=Vertical Pitch H=Horizontal Pitch L G =Luminance of Gap (Inter-electrode space) B p =Luminance of Pel in Bright State D p =Luminance of Pel in Dark State C p =B p /D p =In-Pel Contrast C E =Effective Contrast
Claim 3
Dependent Claim
31 words
The methods of claim 1 wherein the causing step includes: utilizing an LCD which is dark in its power off state; and inverting data signals inoput thereto for driving the device.
Claim 4
Dependent Claim
23 words
The methods of claims 1 wherein the causing step includes: making said inter-electrode spaces permanently dark as a step in the manufacture thereof.
Claim 5
Dependent Claim
30 words
The methods of claims 1 wherein the causing step includes: providing a polarizer on either side of a liquid crystal, said polarizers having their axes of polarization aligned in parallel.
Claim 6
Dependent Claim
132 words
Improved display apparatus employing an electrode excited liquid crystal comprising a multilayer laminated structure including, sequentially, a first polarizing means; a first set of parallel electrodes; liquid crystal material; a second set of parallel electrodes at a predetermined angular offset from said first set of electrodes, intersections of said first and second sets of electrodes defining pels; and a second polarizing means; said geometric relationships within each set and between said two sets of electrodes being determined in accordance with ##EQU6## G V =Vertical Gap Between Conductors G H =Horizontal Gap Between Conductors V=Vertical Pitch H=Horizontal Pitch L G =Luminance of Gap (Inter-electrode space) B p =Luminance of Pel in Bright State D p =Luminance of Pel in Dark State C p =B p /D p =In-Pel Contrast C E =Effective Contrast
Claim 7
Dependent Claim
132 words
Improved display apparatus employing an electrode excited liquid crystal comprising a multilayer laminated structure including, sequentially, a first polarizing means; a first set of parallel electrodes; liquid crystal material; a second set of parallel electrodes at a predetermined angular offset from said first set of electrodes, intersections of said first and second sets of electrodes defining pels; and a second polarizing means; said geometric relationships within each set and between said two sets of electrodes being determined in accordance with ##EQU6## G V =Vertical Gap Between Conductors G H =Horizontal Gap Between Conductors V=Vertical Pitch H=Horizontal Pitch L G =Luminance of Gap (Inter-electrode space) B p =Luminance of Pel in Bright State D p =Luminance of Pel in Dark State C p =B p /D p =In-Pel Contrast C E =Effective Contrast
Claim 8
Dependent Claim
32 words
The apparatus of claim 5 wherein said display apparatus is a matrix addressable display additionally including: means for controlling user perceived flicker using interleaved scanning techniques for refreshing pels in said display.
Claim 9
Independent Claim
14 words
The apparatus of claims 5 or 6 additionally including: a source of back light.
Claim 10
Dependent Claim
21 words
The apparatus of claim 7 additionally including a transparent surface between said second polarizing means and said source of back light.
Claim 11
Dependent Claim
21 words
The apparatus of claim 7 additionally including a transflective surface between said second polarizing means and said source of back light.
Claim 12
Independent Claim
17 words
The apparatus of claims 5 or 6 additionally including a reflective surface adjacent said second polarizing means.
Claim 13
Dependent Claim
112 words
Liquid crystal display apparatus including a first polarizer; a first plurality of parallel excitation electrodes; liquid crystal material; a second plurality of excitation electrodes, positioned orthogonally with respect to said first plurality of excitation electrodes; and a second polarizer, the improvement in user perceived contrast quality characterized by: said two sets of excitation electrodes being geometrically arranged in accordance with ##EQU7## G V =Vertical Gap Between Conductors G H =Horizontal Gap Between Conductors V=Vertical Pitch H=Horizontal Pitch L G =Luminance of Gap (Inter-electrode space) B p =Luminance of Pel in Bright State D p =Luminance of Pel in Dark State C p =B p /D p =In-Pel Contrast C E =Effective Contrast
Claim 14
Dependent Claim
112 words
Liquid crystal display apparatus including a first polarizer; a first plurality of parallel excitation electrodes; liquid crystal material; a second plurality of excitation electrodes, positioned orthogonally with respect to said first plurality of excitation electrodes; and a second polarizer, the improvement in user perceived contrast quality characterized by: said two sets of excitation electrodes being geometrically arranged in accordance with ##EQU7## G V =Vertical Gap Between Conductors G H =Horizontal Gap Between Conductors V=Vertical Pitch H=Horizontal Pitch L G =Luminance of Gap (Inter-electrode space) B p =Luminance of Pel in Bright State D p =Luminance of Pel in Dark State C p =B p /D p =In-Pel Contrast C E =Effective Contrast
Claim 15
Dependent Claim
53 words
The apparatus of claim 11 wherein: each of said first and second pluralities of excitation electrodes comprise transparent electrodes having a width dimension in the range of from about 0.05 mm to about 1.00 mm; and G V and G H have a width of from about 0.005 mm to about 0.05 mm.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-29 | 1992-11-28 | 1993-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-29 | 1996-11-28 | 1997-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-29 | 2000-11-28 | 2001-05-30 | $7700.00 | Window Closed / Lapsed |