US4904058A
Expired / Lapsed
US
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Liquid crystal display panel
Assignee: Sharp Corp
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Filing: 1988-10-13
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Granted: 1990-02-27
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Expires: 2008-10-13
Abstract
Abstract A double-layered super-twisted nematic liquid crystal display panel, comprising a drive cell having a first liquid crystal layer and control electrodes, and a compensator cell having a second liquid crystal layer. In the first aspect, the first and second liquid crystal layers have the same twist angle in reverse directions and the first liquid crystal layer has a product Δn.d of a birefringence Δn and a panel thickness d 1.02-1.20 times larger than that of the second liquid crystal layer. In the second aspect, the second liquid crystal layer has a twist angle larger than that of the second liquid crystal layer by 150°-210°, preferably about 180°.
Inventors
- 👤 Shoichi Kato
- 👤 Kaoru Arai
- 👤 Ikuo Tomita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:44
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1347; G02F1/13471; G02F1/1335; G02F1/13363; G02F1/133636; G02F1/137; G02F1/139; G02F1/1396; G02F1/1397
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
269 words
A double-layered super-twisted nematic liquid crystal display panel, comprising: (A) a first liquid crystal cell including: (i) a first super-twisted nematic liquid crystal layer having a first layer thickness d 1 and a first twist angle of not less than 180° in a first direction and containing first liquid crystal molecules having a first birefringence Δn 1 , and (ii) transparent matrix-type electrodes sandwiching said first super-twisted nematic liquid crystal layer and selectively modulating a state of twist of said first liquid crystal molecules of said first super-twisted nematic liquid crystal layer by selectively applying a voltage thereto; (B) a second liquid crystal cell stacked with said first liquid crystal cell, said second liquid crystal cell including a second super-twisted nematic liquid crystal layer having a second layer thickness d 2 and a second twist angle of not less than 180° in a second direction and containing second liquid crystal molecules having a second birefringence Δn 2 , said second twist angle being almost the same as said first twist angle, said second twist direction being reverse to said first twist direction; and (C) polarizing means for visibly enhancing modulated and non-modulated states of said first liquid crystal molecules in said first liquid crystal cell; wherein a product Δn 1 d 1 of said first birefringence Δn 1 and said first layer thickness d 1 of said first liquid crystal layer is in a range of 0.51-1.68 μm and is 1.02-1.20 times larger than a product Δn 2 d 2 of said second birefringence Δn 2 and said second layer thickness d 2 of the second liquid crystal layer.
Claim 2
Dependent Claim
269 words
A double-layered super-twisted nematic liquid crystal display panel, comprising: (A) a first liquid crystal cell including: (i) a first super-twisted nematic liquid crystal layer having a first layer thickness d 1 and a first twist angle of not less than 180° in a first direction and containing first liquid crystal molecules having a first birefringence Δn 1 , and (ii) transparent matrix-type electrodes sandwiching said first super-twisted nematic liquid crystal layer and selectively modulating a state of twist of said first liquid crystal molecules of said first super-twisted nematic liquid crystal layer by selectively applying a voltage thereto; (B) a second liquid crystal cell stacked with said first liquid crystal cell, said second liquid crystal cell including a second super-twisted nematic liquid crystal layer having a second layer thickness d 2 and a second twist angle of not less than 180° in a second direction and containing second liquid crystal molecules having a second birefringence Δn 2 , said second twist angle being almost the same as said first twist angle, said second twist direction being reverse to said first twist direction; and (C) polarizing means for visibly enhancing modulated and non-modulated states of said first liquid crystal molecules in said first liquid crystal cell; wherein a product Δn 1 d 1 of said first birefringence Δn 1 and said first layer thickness d 1 of said first liquid crystal layer is in a range of 0.51-1.68 μm and is 1.02-1.20 times larger than a product Δn 2 d 2 of said second birefringence Δn 2 and said second layer thickness d 2 of the second liquid crystal layer.
Claim 3
Dependent Claim
17 words
A panel according to claim 1, wherein said transparent matrix-type electrodes have at least 200 multiplexed lines.
Claim 4
Dependent Claim
17 words
A panel according to claim 2, wherein said transparent matrix-type electrodes have at least 400 multiplexed lines.
Claim 5
Dependent Claim
20 words
A panel according to claim 1, wherein the product Δn 1 d 1 is in a range of 0.80-1.07 μm.
Claim 6
Dependent Claim
25 words
A panel according to claim 1, wherein the product Δn 1 d 1 is 1.06-1.12 times larger than the product Δn 2 d 2 .
Claim 7
Dependent Claim
19 words
A panel according to claim 2, which obtains a contrast ratio of more than 6:1 of a visualized image.
Claim 8
Dependent Claim
18 words
A panel according to claim 3, which obtains a contrast of more than 8:1 of a visualized image.
Claim 9
Dependent Claim
182 words
A double-layered super-twisted nematic liquid crystal display panel, comprising: (A) a first liquid crystal cell including: (i) a first super-twisted nematic liquid crystal layer containing first liquid crystal molecules and having a first twist angle T 1 of not less than 180° in a first direction, and (ii) transparent matrix-type electrodes sandwiching said first liquid crystal layer and selectively modulating a state of twist of the liquid crystal molecules of said first super-twisted nematic liquid crystal layer by selectively applying a voltage thereto; (B) a second liquid crystal cell stacked with said first liquid crystal cell, said second liquid crystal cell including a second liquid crystal layer containing second liquid crystal molecules and having a second twist angle T 2 of not less than 180° in a second direction, said second twist direction being reverse to said first twist direction; and (C) polarizing means for visibly enhancing modulated and non-modulated states of said first liquid crystal molecules in said first liquid crystal cell; wherein said second twist angle T 2 is in a range from T 1 +150° to T 1 +210°.
Claim 10
Dependent Claim
182 words
A double-layered super-twisted nematic liquid crystal display panel, comprising: (A) a first liquid crystal cell including: (i) a first super-twisted nematic liquid crystal layer containing first liquid crystal molecules and having a first twist angle T 1 of not less than 180° in a first direction, and (ii) transparent matrix-type electrodes sandwiching said first liquid crystal layer and selectively modulating a state of twist of the liquid crystal molecules of said first super-twisted nematic liquid crystal layer by selectively applying a voltage thereto; (B) a second liquid crystal cell stacked with said first liquid crystal cell, said second liquid crystal cell including a second liquid crystal layer containing second liquid crystal molecules and having a second twist angle T 2 of not less than 180° in a second direction, said second twist direction being reverse to said first twist direction; and (C) polarizing means for visibly enhancing modulated and non-modulated states of said first liquid crystal molecules in said first liquid crystal cell; wherein said second twist angle T 2 is in a range from T 1 +150° to T 1 +210°.
Claim 11
Dependent Claim
12 words
A panel according to claim 8, wherein T 2 =T 1 +180°.
Claim 12
Dependent Claim
33 words
A panel according to claim 8, wherein a drive cell has a product of a birefringence of said liquid crystal and a cell thickness 1.02-1.20 times larger than that of a compensator cell.
Claim 13
Dependent Claim
22 words
A panel according to claim 10, wherein said drive cell has a product 1.06-1.12 times larger than that of said compensator cell.
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) | 1993-02-26 | 1993-08-28 | 1994-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-26 | 1997-08-28 | 1998-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-26 | 2001-08-28 | 2002-02-27 | $7700.00 | Window Closed / Lapsed |