US4906073A
Expired / Lapsed
US
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Liquid crystal display device using nematic liquid crystal having twisted helical structure and a phase correction plate
Assignee: Hitachi Ltd
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Filing: 1988-07-27
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Granted: 1990-03-06
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Expires: 2008-07-27
Abstract
Abstract In a liquid crystal display device, light transmitting through a liquid crystal layer is colored depending on the structural conditions of the liquid crystal display device. The phase of the transmission light is corrected by means of a phase correction plate to make the transmission light approximate achromatic color, thereby permitting monochromatic display or color display.
Inventors
- 👤 Katuyuki Hunahata
- 👤 Yuji Mori
- 👤 Jun-ichi Hirakata
- 👤 Yoshiharu Nagae
- 👤 Hideaki Kawakami
- 👤 Kiyoshige Kinugawa
- 👤 Yasuhiko Kando
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:54
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1347; G02F1/13471; G02F1/1335; G02F1/13363; G02F1/137; G02F1/139; G02F1/1396; G02F1/1397; G02F2202/00; G02F2202/40; G02F2413/00; G02F2413/01; G02F2413/08
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
143 words
A liquid crystal display device comprising: a liquid crystal layer of the twist nematic type having a twist angle which exceeds 90°, said layer being interposed between a plurality of electrodes which are opposed to each other; a pair of polarizer plates so disposed as to sandwich said liquid crystal layer; and a phase plate means for providing phase correction interposed between said pair of polarized plates, said phase plate means comprising a birefringent organic film having substantially the same characteristic of wavelength dispersion as that of said liquid crystal layer and with a selected optical thickness determined by the optical thickness and twist angle of the liquid crystal layer, said phase plate means being disposed at an angle with respect to a polarization axis or absorption axis of the polarizer plate to cause birefrigence to retard an overall wavelength of visible light.
Claim 2
Dependent Claim
143 words
A liquid crystal display device comprising: a liquid crystal layer of the twist nematic type having a twist angle which exceeds 90°, said layer being interposed between a plurality of electrodes which are opposed to each other; a pair of polarizer plates so disposed as to sandwich said liquid crystal layer; and a phase plate means for providing phase correction interposed between said pair of polarized plates, said phase plate means comprising a birefringent organic film having substantially the same characteristic of wavelength dispersion as that of said liquid crystal layer and with a selected optical thickness determined by the optical thickness and twist angle of the liquid crystal layer, said phase plate means being disposed at an angle with respect to a polarization axis or absorption axis of the polarizer plate to cause birefrigence to retard an overall wavelength of visible light.
Claim 3
Dependent Claim
25 words
A liquid crystal display device according to claim 1 wherein said film is made of an organic material including polycarbonate, polyvinyl alcohol or tri-anil cyanolate.
Claim 4
Dependent Claim
35 words
A liquid crystal display device according to claim 1 wherein said liquid crystal layer has the product of anisotropy of birefringent index Δn and layer thickness d which ranges from 0.4 μm to 2.5 μm.
Claim 5
Dependent Claim
25 words
A liquid crystal display device according to claim 3, wherein said birefringent organic film is disposed closer to a backlight than said liquid crystal layer.
Claim 6
Dependent Claim
35 words
A liquid crystal display device according to claim 1 wherein said liquid crystal layer has the product of anisotropy of birefringent index Δn and layer thickness d which ranges from 0.4 μm to 1.0 μm.
Claim 7
Dependent Claim
28 words
A liquid crystal display device according to claim 5, wherein said phase plate means is made up of a plurality of the organic films superimposed on each other.
Claim 8
Dependent Claim
19 words
A liquid crystal display device according to claim 1, wherein said birefringent organic film is made of tri-anil cyanolate.
Claim 9
Dependent Claim
24 words
A liquid crystal display device according to claim 1, wherein said twist angle of the liquid crystal layer ranges between 180 ° and 270°.
Claim 10
Dependent Claim
77 words
A liquid crystal display device comprising: a first liquid crystal layer of the twist nematic type having a twist angle which exceeds 90°,said layer being interposed between a plurality of electrodes which are opposed to each other; a pair of polarizer plates so disposed as to sandwich said first liquid crystal layer; and at least one second liquid crystal layer having a twist angle which is substantially 0° or 180° and interposed between said paired polarizer plates.
Claim 11
Dependent Claim
77 words
A liquid crystal display device comprising: a first liquid crystal layer of the twist nematic type having a twist angle which exceeds 90°,said layer being interposed between a plurality of electrodes which are opposed to each other; a pair of polarizer plates so disposed as to sandwich said first liquid crystal layer; and at least one second liquid crystal layer having a twist angle which is substantially 0° or 180° and interposed between said paired polarizer plates.
Claim 12
Dependent Claim
36 words
A liquid crystal display device according to claim 9 wherein said first liquid crystal layer has the product of anisotropy of birefringent index Δn and layer thickness d which ranges from 0.4 μm to 82.5 μm.
Claim 13
Dependent Claim
37 words
A liquid crystal display device according to claim 9 wherein said first liquid crystal layer has the product of anisotropy of birefringent index Δn and layer thickness d which ranges from 0.4 μm to 1.0 82 m.
Claim 14
Dependent Claim
25 words
A liquid crystal display device according to claim 9, wherein the twist angle of the first liquid crystal layer ranges between 180° and 270 °.
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) | 1993-03-05 | 1993-09-04 | 1994-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-05 | 1997-09-04 | 1998-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-05 | 2001-09-04 | 2002-03-06 | $7700.00 | Window Closed / Lapsed |