US5213852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phase difference film and liquid crystal display having the same
Assignee: Fujifilm Holdings Corp
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Filing: 1991-11-21
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Granted: 1993-05-25
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Expires: 2011-11-21
Abstract
Abstract Disclosed is a phase difference film in the form of a uniaxially stretched film having a negative intrinsic birefringence which is made of a styrene/acrylonitrile copolymer. The copolymer has a styrene unit and an acrylonitrile unit in the range of 85/15 to 50/50 by weight (former/latter) and a weight-average molecular weight in the range of 200,000 to 900,000. The liquid crystal display provided with the phase difference film is also disclosed.
Inventors
- 👤 Kohei Arakawa
- 👤 Sumio Ohtani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:20
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/13363; C; C09; C09K; C09K2323/00; C09K2323/02; G02F2413/00; G02F2413/02; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
121 words
A liquid crystal display which comprises a liquid crystal cell comprising a pair of substrates provided with a transparent electrode and a twist orientated nematic liquid crystal sealed therebetween, at least one phase difference film provided on at least one of the substrates and a pair of polarizing sheets arranged on the both sides of the cell wherein; said phase difference film comprises at least one uniaxially stretched film of a polymer having a positive intrinsic birefringence and at least one uniaxially stretched film of a copolymer having a negative intrinsic birefringence, said copolymer comprising a styrene unit and an acrylonitrile unit in the range of 85/15 to 50/50 by weight and having a weight-average molecular weight of 200,000 to 900,000.
Claim 2
Dependent Claim
121 words
A liquid crystal display which comprises a liquid crystal cell comprising a pair of substrates provided with a transparent electrode and a twist orientated nematic liquid crystal sealed therebetween, at least one phase difference film provided on at least one of the substrates and a pair of polarizing sheets arranged on the both sides of the cell wherein; said phase difference film comprises at least one uniaxially stretched film of a polymer having a positive intrinsic birefringence and at least one uniaxially stretched film of a copolymer having a negative intrinsic birefringence, said copolymer comprising a styrene unit and an acrylonitrile unit in the range of 85/15 to 50/50 by weight and having a weight-average molecular weight of 200,000 to 900,000.
Claim 3
Dependent Claim
21 words
The liquid crystal display as claimed in claim 1 wherein said copolymer has a weight-average molecular weight of 250,000 to 800,000.
Claim 4
Dependent Claim
29 words
The liquid crystal display as claimed in claim 1 wherein said copolymer has a styrene unit and an acrylonitrile unit in the range of 75/25 to 60/40 by weight.
Claim 5
Dependent Claim
59 words
The liquid crystal display as claimed in claim 1 wherein the phase difference film is a laminated film comprising a uniaxially stretched film of a polymer having a positive intrinsic birefringence and a uniaxially stretched film of a copolymer having a negative intrinsic birefringence, and the stretched axes of the two films intersect at almost right angles each other.
References Cited (Backward Citations)
US3862880A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-24 | 1996-11-23 | 1997-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-24 | 2000-11-23 | 2001-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-24 | 2004-11-23 | 2005-05-25 | $7700.00 | Window Closed / Lapsed |