US4119367A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal displays
Assignee: Individual
•
Filing: 1976-03-03
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Granted: 1978-10-10
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Expires: 1996-03-03
Abstract
Abstract A liquid crystal display comprises a liquid crystal material layer contained between transparent slides which carry electrodes arranged in lines and columns to form an x, y matrix with x, y intersections. The liquid crystal layer at the intersections are turned on line by line by a blanking voltage, turned off by application of a zero voltage, and held at a threshold voltage at other times. The voltages are applied from a two phase supply in the form of two sinusoidal waves spaced 60° apart in phase. Threshold voltages at an intersection are maintained by applying one of the two waveforms to x electrodes and a zero voltage to y electrodes. A zero voltage at x, y intersections is arranged by applying the other of the two waveforms to both x, y electrodes.
Inventors
- 👤 Edward Peter Raynes
- 👤 Ian Alexander Shanks
- 👤 John Charles Varney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:49
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/13725; G02F1/133; G02F1/13306
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
168 words
A method of addressing a matrix liquid crystal display which comprises a layer of liquid crystal material contained between a first and a second slide at lease one of which is transparent, said first slide having a first set of transparent strip electrodes, said second slide having a second set of transparent strip electrodes, the two sets of electrodes being arranged to form a matrix of electrode intersections, said method comprising applying a blanking voltage across a plurality of active areas of liquid crystal to change them to their on state; applying a first of a two phase voltage supply source which supplies two sinusoidal waveforms 60° apart in phase to an electrode in both sets of electrodes at an electrode intersection which is to be turned from an on to an off state; applying the second of said sinusoidal waveforms to the remaining first set of electrodes, and applying a zero voltage to the remaining second set of electrodes, whereby the remaining intersections receive a threshold voltage.
Claim 2
Independent Claim
168 words
A method of addressing a matrix liquid crystal display which comprises a layer of liquid crystal material contained between a first and a second slide at lease one of which is transparent, said first slide having a first set of transparent strip electrodes, said second slide having a second set of transparent strip electrodes, the two sets of electrodes being arranged to form a matrix of electrode intersections, said method comprising applying a blanking voltage across a plurality of active areas of liquid crystal to change them to their on state; applying a first of a two phase voltage supply source which supplies two sinusoidal waveforms 60° apart in phase to an electrode in both sets of electrodes at an electrode intersection which is to be turned from an on to an off state; applying the second of said sinusoidal waveforms to the remaining first set of electrodes, and applying a zero voltage to the remaining second set of electrodes, whereby the remaining intersections receive a threshold voltage.
Claim 3
Dependent Claim
39 words
The method of claim 1 wherein the electrode intersections are arranged in lines and columns and the said application of a voltage across a plurality of active areas of liquid crystal is applied to a line at a time.
Claim 4
Dependent Claim
63 words
The method of claim 1 wherein the electrode intersections are arranged in lines and columns and the voltage applied across a plurality of active areas of liquid crystal is applied to the whole display, a below threshold voltage is applied line by line, and a voltage close to the threshold voltage is applied at intersections which do not receive the below threshold voltage.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein the liquid crystal layer is a nematic liquid crystal material containing chloesteric liquid crystal material.
Claim 6
Dependent Claim
16 words
The method of claim 4 wherein the liquid crystal layer contains at least one pheochroic dye.
Claim 7
Independent Claim
153 words
A method of addressing a matrix liquid crystal display which comprises a layer of nematic and cholesteric liquid crystal material contained between two slides at least one of which is transparent, said slides having transparent x, and y strip electrodes arranged in lines and columns on the slides to form an x, y matrix having x times y electrode intersections, said method comprising applying a blanking voltage across said layer in a line to turn the layer to an on state, applying a first of a two phase voltage supply source which supplies two sinusoidal waveforms 60° apart in phase to both x and y electrodes at an electrode intersection which is to be turned from the on to off state, applying the second of said sinusoidal waveforms to the remaining x electrodes, and applying a zero voltage to the remaining y electrodes whereby the remaining x, y intersections receive a threshold voltage.
Claim 8
Independent Claim
153 words
A method of addressing a matrix liquid crystal display which comprises a layer of nematic and cholesteric liquid crystal material contained between two slides at least one of which is transparent, said slides having transparent x, and y strip electrodes arranged in lines and columns on the slides to form an x, y matrix having x times y electrode intersections, said method comprising applying a blanking voltage across said layer in a line to turn the layer to an on state, applying a first of a two phase voltage supply source which supplies two sinusoidal waveforms 60° apart in phase to both x and y electrodes at an electrode intersection which is to be turned from the on to off state, applying the second of said sinusoidal waveforms to the remaining x electrodes, and applying a zero voltage to the remaining y electrodes whereby the remaining x, y intersections receive a threshold voltage.
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) | 1981-10-09 | 1982-04-10 | 1982-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-09 | 1986-04-10 | 1986-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-09 | 1990-04-10 | 1990-10-10 | $7700.00 | Window Closed / Lapsed |