US4775221A
Expired / Lapsed
US
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Method of and apparatus for controlling temperature of a liquid crystal cell
Assignee: Transamerica Business Credit Corp
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Filing: 1986-10-02
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Granted: 1988-10-04
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Expires: 2006-10-02
Abstract
Abstract Operating temperature of a liquid crystal cell is controlled by passing heated air on its surface, the heater for the air being operated according to the average temperature of the cell measured by a sensor. Fine control is effected by means of resistive heaters affixed on the exterior surface and by electrodes provided at strategic locations inside to pass current through a conductive layer.
Inventors
- 👤 James A. Baumgartner, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:17
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/133382
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
103 words
A liquid crystal cell comprising a liquid crystal layer with a surface defining one or more individually temperature-controllable regions, said temperature-controllable regions defining boundary lines therebetween, a conductive layer which is substantially parallel and adjacent to said liquid crystal layer, elongated electrodes disposed on said conductive layer along said boundaries and/or outer edges of said liquid crystal layer such that each of said temperature-controllable regions has a pair of said electrodes on opposite sides thereof, and power means for applying a potential difference between selected one or more of said pairs of electrodes for passing a current and thereby heating the region therebetween.
Claim 2
Dependent Claim
103 words
A liquid crystal cell comprising a liquid crystal layer with a surface defining one or more individually temperature-controllable regions, said temperature-controllable regions defining boundary lines therebetween, a conductive layer which is substantially parallel and adjacent to said liquid crystal layer, elongated electrodes disposed on said conductive layer along said boundaries and/or outer edges of said liquid crystal layer such that each of said temperature-controllable regions has a pair of said electrodes on opposite sides thereof, and power means for applying a potential difference between selected one or more of said pairs of electrodes for passing a current and thereby heating the region therebetween.
Claim 3
Dependent Claim
26 words
The liquid crystal cell of claim 1 further comprising a temperature sensor for outputting a temperature signal indicative of the average temperature of said temperature-controllable cell.
Claim 4
Independent Claim
105 words
A method of controlling the temperature of a liquid crystal cell which includes a conductive layer parallel to a surface thereof, one or more separate regions being defined on said surface, said method comprising the steps of providing electrodes on said conductive layer along boundaries between said regions and/or along outer edges of said conductive layer such that each of said regions has a pair of said electrodes on opposite sides thereof, and applying a potential difference between selected one or more of said electrodes to pass a current and thereby heat the region or regions between said selected one or more of said electrodes.
Claim 5
Independent Claim
105 words
A method of controlling the temperature of a liquid crystal cell which includes a conductive layer parallel to a surface thereof, one or more separate regions being defined on said surface, said method comprising the steps of providing electrodes on said conductive layer along boundaries between said regions and/or along outer edges of said conductive layer such that each of said regions has a pair of said electrodes on opposite sides thereof, and applying a potential difference between selected one or more of said electrodes to pass a current and thereby heat the region or regions between said selected one or more of said electrodes.
Claim 6
Dependent Claim
19 words
The method of claim 3 further comprising the step of causing heated air to flow controllably on said surface.
Claim 7
Dependent Claim
20 words
The method of claim 4 wherein said heated air is circulated inside a recirculating duct containing said liquid crystal cell.
Claim 8
Dependent Claim
26 words
The method of claim 4 wherein said heated air is controllably heated according to a signal indicative of the average temperature of said liquid crystal cell.
Claim 9
Dependent Claim
26 words
The method of claim 6 further comprising the step of placing a temperature sensor on said surface, said temperature sensor being connected to output said signal.
Claim 10
Dependent Claim
18 words
The method of claim 3 further comprising the step of causing current to pass through said conductive layer.
Claim 11
Dependent Claim
33 words
The method of claim 8 further comprising the step of attaching electrodes to said conductive layer at opposite edges of said one or more regions and causing current to flow between said electrodes.
Claim 12
Independent Claim
31 words
The method of controlling the temperature of a liquid crystal cell, said method comprising the step of causing heated air to flow controllably on a surface of said liquid crystal cell.
Claim 13
Independent Claim
31 words
The method of controlling the temperature of a liquid crystal cell, said method comprising the step of causing heated air to flow controllably on a surface of said liquid crystal cell.
Claim 14
Dependent Claim
20 words
The method of claim 10 wherein said heated air is circulated in a recirculating duct containing said liquid crystal cell.
Claim 15
Dependent Claim
26 words
The method of claim 10 wherein said heated air is controllably heated according to a signal indicative of the average temperature of said liquid crystal cell.
Claim 16
Dependent Claim
26 words
The method of claim 12 further comprising the step of placing a temperature sensor on said surface, said temperature sensor being connected to output said signal.
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) | 1991-10-04 | 1992-04-04 | 1992-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-04 | 1996-04-04 | 1996-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-04 | 2000-04-04 | 2000-10-04 | $7700.00 | Window Closed / Lapsed |