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US5032008A Expired / Lapsed US ⏱️ 0.0 years remaining

Liquid crystal display device having optical delay plates

Assignee: Toshiba Corp
•
Filing: 1989-07-07
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Granted: 1991-07-16
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Expires: 2009-07-07
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Abstract

Abstract This invention discloses a liquid crystal display device including a liquid crystal cell having two substrates, arranged substantially parallel to each other, and having electrodes on their opposing surfaces, and a liquid crystal composition held between the substrates, first and second polarizers arranged at both sides of the liquid crystal cell, a first optical delay plate arranged between the liquid crystal cell and the second polarizer, and a second optical delay plate arranged between the first optical delay plate and the second polarizer, wherein liquid crystal molecules of the liquid crystal composition are arranged in twisted mode from a second polarizer side to a first polarizer side, the first and second optical delay plates are arranged such that optical axes thereof cross to form an acute angle, and a twist direction of the liquid crystal molecules in the state of twisted mode is the same as a direction from the optical axis of the second optical delay plate toward the first optical delay plate shifted by the acute angle. A display performed by the liquid crystal display device of this invention is a high-contrast, bright, and achromatic b/w display. The liquid crystal display device of this invention has a wide viewing angle. The liquid crystal display device of this invention is inexpensive.

Inventors

  • 👤 Tomiaki Yamamoto
  • 👤 Akio Murayama
  • 👤 Susumu Kondo
  • 👤 Hitoshi Hato
  • 👤 Shinichi Kamagami
  • 👤 Shoichi Matsumoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 05:46
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/13363; G02F1/137; G02F1/139; G02F1/1396; G02F1/1397; G02F2202/00; G02F2202/40; G02F2413/00; G02F2413/02; G02F2413/07; G02F2413/08

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 173 words
A liquid crystal display device comprising: a liquid crystal cell including two substrates which are arranged substantially parallel to each other and have electrodes on opposing surfaces thereof, and a liquid crystal composition held between said substrates; first and second polarizers arranged at both sides of said liquid crystal cell; a first optical delay plate arranged between said liquid crystal cell and said second polarizer; and a second optical delay plate arranged between said first optical delay plate and said second polarizer, wherein liquid crystal molecules in said liquid crystal composition are arranged in a twisted mode between 180° to 360° from a second polarizer side to a first polarizer side, said first and second optical delay plates are arranged such that optical axes thereof cross to form an acute angle, and a twist direction of said liquid crystal molecules in the state of twisted mode is the same as a direction from the optical axis of said second optical delay plate toward said first optical delay plate shifted by the acute angle.
Claim 2
Dependent Claim 173 words
A liquid crystal display device comprising: a liquid crystal cell including two substrates which are arranged substantially parallel to each other and have electrodes on opposing surfaces thereof, and a liquid crystal composition held between said substrates; first and second polarizers arranged at both sides of said liquid crystal cell; a first optical delay plate arranged between said liquid crystal cell and said second polarizer; and a second optical delay plate arranged between said first optical delay plate and said second polarizer, wherein liquid crystal molecules in said liquid crystal composition are arranged in a twisted mode between 180° to 360° from a second polarizer side to a first polarizer side, said first and second optical delay plates are arranged such that optical axes thereof cross to form an acute angle, and a twist direction of said liquid crystal molecules in the state of twisted mode is the same as a direction from the optical axis of said second optical delay plate toward said first optical delay plate shifted by the acute angle.
Claim 3
Dependent Claim 24 words
A device according to claim 1, wherein each of said first and second optical delay plates comprises a stretched film consisting of polyvinyl alcohol.
Claim 4
Dependent Claim 38 words
A device according to claim 1, wherein a retardation value of said liquid crystal cell is about 0.69 μm, and a total of retardation values of said first and second optical delay plates is 0.693 to 0.800 μm.

References Cited (Backward Citations)

GB2028527A Cited
GB2171549A Cited
US4852976A Cited
US4909606A Cited
EP0246842A2 Cited
US4844569A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-07-15 1995-01-14 1995-07-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-07-15 1999-01-14 1999-07-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-07-15 2003-01-14 2003-07-16 $7700.00 Window Closed / Lapsed

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