Patent US4779956A successfully refreshed from Google Patents.
US4779956A
Expired / Lapsed
US
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Driving circuit for liquid crystal display
Assignee: Panasonic Holdings Corp
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Filing: 1986-05-09
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Granted: 1988-10-25
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Expires: 2006-05-09
Abstract
Abstract A liquid crystal display having plural liquid crystal cells which are constituted as a matrix, each cell respectively having one transistor and being supplied with image signals by such transistors. The driving circuit for a liquid crystal display of the present invention periodically changes the polarity of the voltage of the image signals and the voltage between both terminals of the liquid crystal cell so as to switch the transistor, and the driving circuit generates gate signals which are impressed on the gate electrode of each transistor, the gate signals having a lowest voltage which is lower than a voltage obtained by subtracting the amplitude voltage of the common electrode of the liquid crystal cells from the lowest voltage in the driving voltage obtained from the image signals.
Inventors
- 👤 Yukio Nemoto
- 👤 Koushiro Takahashi
- 👤 Masaki Hosono
- 👤 Hiroshi Kitahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:38
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3696; G09G3/3614; G09G3/3674; G09G3/3677; G09G2310/00; G09G2310/02; G09G2310/0264; G09G2310/0289
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
189 words
A driving circuit for a liquid crystal display, comprising: voltage changing means coupled to first and second voltage supplies and to common electrodes of respective liquid crystal cells for alternating the polarity of a voltage applied across said respective liquid crystal cells, polarity alternating means coupled to image signal input terminals of said driving circuit for alternating the polarity of a driving voltage, which corresponds to image signals to be applied to other electrodes of said liquid crystal cells, synchronously with said voltage alternation of said voltage changing means, plural transistors each connected by its source electrode to one of said other electrodes of said respective liquid crystal cells, by its drain electrode to output terminals of said polarity alternating means, and by its gate electrode to receive respective gate signals, and gate voltage generating means coupled to said gate electrode of said plural transistors for generating said gate signals, each having a lowest voltage which is lower than a voltage made by subtracting an amplitude voltage of said common electrode from the lowest voltage in said driving voltage, and for applying said gate signals to said gate electrodes.
Claim 2
Dependent Claim
189 words
A driving circuit for a liquid crystal display, comprising: voltage changing means coupled to first and second voltage supplies and to common electrodes of respective liquid crystal cells for alternating the polarity of a voltage applied across said respective liquid crystal cells, polarity alternating means coupled to image signal input terminals of said driving circuit for alternating the polarity of a driving voltage, which corresponds to image signals to be applied to other electrodes of said liquid crystal cells, synchronously with said voltage alternation of said voltage changing means, plural transistors each connected by its source electrode to one of said other electrodes of said respective liquid crystal cells, by its drain electrode to output terminals of said polarity alternating means, and by its gate electrode to receive respective gate signals, and gate voltage generating means coupled to said gate electrode of said plural transistors for generating said gate signals, each having a lowest voltage which is lower than a voltage made by subtracting an amplitude voltage of said common electrode from the lowest voltage in said driving voltage, and for applying said gate signals to said gate electrodes.
Claim 3
Dependent Claim
20 words
A driving circuit for a liquid crystal display in accordance with claim 1, wherein said transistors are thin film transistors.
References Cited (Backward Citations)
US4158860A
Cited
US4319237A
Cited
US4447812A
Cited
US4485380A
Cited
US4427978A
Cited
JPH111298A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-10-25 | 1992-04-25 | 1992-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-25 | 1996-04-25 | 1996-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-25 | 2000-04-25 | 2000-10-25 | $7700.00 | Window Closed / Lapsed |