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US5298199A Expired / Lapsed US ⏱️ 0.0 years remaining

Optical birefringence compensator adapted for LCD

Assignee: Stanley Electric Co Ltd
•
Filing: 1991-10-11
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Granted: 1994-03-29
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Expires: 2011-10-11
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Abstract

Abstract Ionomer resin sheet is stretched in one direction in the plane of sheet to give uniaxial anisotropy, and then heated above the melting point under pressure to cause relaxation of the anisotropy. After cooling, a sheet of biaxial anisotropy is obtained. The degree of anisotropy depends on the initial stretching, heating temperature, heating time and pressure.

Inventors

  • 👤 Shinichi Hirose
  • 👤 Jean F. Clerc

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 13:32
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/30; G02B5/3083; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/13363; G02F1/133634; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31855; Y10T428/31935

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 73 words
A method of producing a biaxial optical compensator, comprising the successive steps of: (a) stretching an ion-containing polymer sheet to impart optical anisotropy thereto; (b) sandwiching the thus stretched ion-containing polymer sheet between two substrates while maintaining the optical anisotropy; (c) heating the ion containing polymer sheet; (d) discontinuing heating before the stretched ion-containing polymer sheet becomes optically isotropic; and thereafter (e) cooling the ion-containing polymer sheet thereby obtaining an optically biaxial sheet.
Claim 2
Independent Claim 73 words
A method of producing a biaxial optical compensator, comprising the successive steps of: (a) stretching an ion-containing polymer sheet to impart optical anisotropy thereto; (b) sandwiching the thus stretched ion-containing polymer sheet between two substrates while maintaining the optical anisotropy; (c) heating the ion containing polymer sheet; (d) discontinuing heating before the stretched ion-containing polymer sheet becomes optically isotropic; and thereafter (e) cooling the ion-containing polymer sheet thereby obtaining an optically biaxial sheet.
Claim 3
Dependent Claim 14 words
The method according to claim 1, wherein the ion-containing polymer is an ionomer resin.
Claim 4
Dependent Claim 17 words
The method according to claim 2, wherein the ionomer resin has ethylene-methacrylate copolymer bridged with metal ions.
Claim 5
Dependent Claim 20 words
The method according to claim 2, wherein heating step (c) includes pressing the ionomer resin sheet between the two substrates.
Claim 6
Dependent Claim 16 words
The method according to claim 2, wherein heating step (c) is conducted in an autoclave furnace.

References Cited (Backward Citations)

GB1462978A Cited
US4385806A Cited
JPS58171407A Cited
US4514452A Cited
US4701028A Cited
EP0239433A1 Cited
US4813770A Cited
EP0367288A2 Cited
EP0376696A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-03-28 1997-09-27 1998-03-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-03-28 2001-09-27 2002-03-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-03-28 2005-09-27 2006-03-29 $7700.00 Window Closed / Lapsed

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