US4140371A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal display devices
Assignee: Hitachi Ltd
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Filing: 1976-10-21
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Granted: 1979-02-20
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Expires: 1996-10-21
Abstract
Abstract In a liquid crystal display device of the twisted nematic type comprising upper and lower substrates, upper and lower transparent electrodes formed on the inner surfaces of respective substrates, a liquid crystal interposed between the upper and lower electrodes with its molecules oriented in a twisted arrangement, each of the upper and lower electrodes is constituted by a plurality of electrode segments, and the upper electrode segments are displaced toward lower edge of the display with respect to the corresponding lower electrode segments.
Inventors
- 👤 Mikio Kanazaki
- 👤 Tadashi Ishibashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:42
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/133345; G02F1/1343; G02F1/134309; G02F1/134327; G02F1/137; G02F1/139; G02F1/1396
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
198 words
In a twisted nematic type liquid crystal display device of the class including upper and lower spaced substrates, transparent upper and lower electrodes respectively formed on the inner surfaces of said upper and lower substrates, a liquid crystal, interposed between said upper and lower electrodes, means to cause the molecules of said liquid crystal to orient in a twisted arrangement, the improvement to prevent edge domain formation wherein each of said transparent upper and lower electrodes is constituted by a plurality of pairs of substantially overlayed upper and lower electrode segments, said means for orienting said molecules comprises means for selectively applying an electric field between pairs of upper and lower electrode segments, and at least some of the upper electrode segments are displaced toward the lower edge of a pattern to be displayed with respect to the corresponding lower electrode segments to cause the lower edge of said some upper electrode segments of a pair to not overlay the lower electrode of its pair by an amount sufficient to prevent edge domain formation in the liquid crystal when an electric field is applied between said some upper electrode segments and the corresponding lower electrode of the pairs.
Claim 2
Dependent Claim
198 words
In a twisted nematic type liquid crystal display device of the class including upper and lower spaced substrates, transparent upper and lower electrodes respectively formed on the inner surfaces of said upper and lower substrates, a liquid crystal, interposed between said upper and lower electrodes, means to cause the molecules of said liquid crystal to orient in a twisted arrangement, the improvement to prevent edge domain formation wherein each of said transparent upper and lower electrodes is constituted by a plurality of pairs of substantially overlayed upper and lower electrode segments, said means for orienting said molecules comprises means for selectively applying an electric field between pairs of upper and lower electrode segments, and at least some of the upper electrode segments are displaced toward the lower edge of a pattern to be displayed with respect to the corresponding lower electrode segments to cause the lower edge of said some upper electrode segments of a pair to not overlay the lower electrode of its pair by an amount sufficient to prevent edge domain formation in the liquid crystal when an electric field is applied between said some upper electrode segments and the corresponding lower electrode of the pairs.
Claim 3
Dependent Claim
87 words
The liquid crystal display device according to claim 1 wherein only the upper electrode segments extending in the direction perpendicular to the direction from which the display is viewed are displaced toward said lower edge with respect to the corresponding lower electrode segments by an amount which substantially aligns the molecules between the corresponding edges of said upper and lower segments of a pair with the molecules in the central portion of said segments when said pair has an electric field provided by said field applying means.
Claim 4
Dependent Claim
85 words
The liquid crystal display device according to claim 1 wherein said plurality of electrode segments are arranged in a display pattern of a digit 8, said view position is located below the vertical axis of the display pattern and the upper electrode segments are displaced toward said lower edge with respect to the corresponding lower electrode segments by an amount substantially the same as the space between said upper and lower electrodes, each pair of said segments being of substantially the same size and shape.
Claim 5
Dependent Claim
44 words
The liquid crystal display device according to claim 3 wherein the segments positioned at the lower side of a digit 8 shaped display pattern have a substantially frustum shape, and projections are formed on the opposite corners of the lower side of the frustum.
Claim 6
Dependent Claim
21 words
The liquid crystal display device according to claim 4 wherein the width of said projections increases gradually toward said lower edge.
Claim 7
Dependent Claim
16 words
The liquid crystal display device according to claim 4 wherein said projections include a rectangular position.
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) | 1982-02-19 | 1982-08-21 | 1983-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-19 | 1986-08-21 | 1987-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-19 | 1990-08-21 | 1991-02-20 | $7700.00 | Window Closed / Lapsed |