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US4984873A Expired / Lapsed US ⏱️ 0.0 years remaining

Liquid crystal display device

Assignee: Ricoh Co Ltd
•
Filing: 1988-08-31
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Granted: 1991-01-15
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Expires: 2008-08-31
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Abstract

Abstract A liquid crystal display device, comprising: (a) a liquid crystal layer disposed between a pair of light permeable substrates, an alignment of a liquid crystal of said liquid crystal layer being substantially horizontal relative to said substrates in the absence of applied voltage, said liquid crystal layer having a twisted structure with a twist angle along a direction of a thickness thereof such that an adequate display is provided without substantially reducing the time dimensional driving; (b) a pair of polarization means disposed on both outsides of said liquid crystal layer; and (c) at least one birefringent medium layer disposed between one side of said liquid crystal layer and the polarization means on said one side of said liquid crystal layer; an optical axis of said birefringent medium layer being inclined toward a polarization axis of the adjacent polarization means, the alignment direction of said liquid crystal on a surface of another side of said liquid crystal layer making an angle from 0° to 25° relative to the polarization transmission axis or an absorption axis of the polarization means, the direction of a maximum refractive index of said birefringent medium layer and the alignment direction of said liquid crystal on a surface of said one side of said liquid crystal layer on a surface of said one side of said liquid crystal layer making an angle from 20° to 130° while a retardation of said birefringent medium layer is in a range of 0.125 πrad to 1 πrad and a retardation of said liquid crystal layer is about 3/2 πrad or about 2 πrad.

Inventors

  • 👤 Yasuyuki Takiguchi
  • 👤 Akihiko Kanemoto
  • 👤 Kenya Yokoi
  • 👤 Haruo Iimura
  • 👤 Takamichi Enomoto
  • 👤 Sumio Kamoi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 17:29
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/13363; G02F2202/00; G02F2202/40; G02F2413/00; G02F2413/01; G02F2413/08

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 251 words
A liquid crystal display device, comprising: (a) a liquid crystal layer disposed between a pair of light permeable substrates, an alignment of a liquid crystal of said liquid crystal layer being substantially horizontal relative to said substrates in the absence of applied voltage, said liquid crystal layer having a twisted structure with a twist angle along a direction of a thickness thereof such that an adequate display is provided without substantially reducing the time divisional driving; (b) a pair of polarization means disposed on both outsides of said liquid crystal layer; and (c) at least one birefringent medium layer disposed between one side of said liquid crystal layer and the polarization means on said one side of said liquid crystal layer; an optical axis of said birefringent medium layer being inclined toward a polarization axis of the adjacent polarization means, the alignment direction of said liquid crystal on a surface of another side of said liquid crystal layer making an angle from 0° to 25° relative to the polarization transmission axis or an absorption axis of the polarization means, the direction of a maximum refractive index of said birefringent medium layer and the alignment direction of said liquid crystal on a surface of said one side of said liquid crystal layer making an angle 20° to 130° while a retardation of said birefringent medium layer is in a range of 0.125π rad to 1π rad and a retardation of said liquid crystal layer is about 3/2π rad or about 2π rad.
Claim 2
Dependent Claim 251 words
A liquid crystal display device, comprising: (a) a liquid crystal layer disposed between a pair of light permeable substrates, an alignment of a liquid crystal of said liquid crystal layer being substantially horizontal relative to said substrates in the absence of applied voltage, said liquid crystal layer having a twisted structure with a twist angle along a direction of a thickness thereof such that an adequate display is provided without substantially reducing the time divisional driving; (b) a pair of polarization means disposed on both outsides of said liquid crystal layer; and (c) at least one birefringent medium layer disposed between one side of said liquid crystal layer and the polarization means on said one side of said liquid crystal layer; an optical axis of said birefringent medium layer being inclined toward a polarization axis of the adjacent polarization means, the alignment direction of said liquid crystal on a surface of another side of said liquid crystal layer making an angle from 0° to 25° relative to the polarization transmission axis or an absorption axis of the polarization means, the direction of a maximum refractive index of said birefringent medium layer and the alignment direction of said liquid crystal on a surface of said one side of said liquid crystal layer making an angle 20° to 130° while a retardation of said birefringent medium layer is in a range of 0.125π rad to 1π rad and a retardation of said liquid crystal layer is about 3/2π rad or about 2π rad.

References Cited (Backward Citations)

JPS5569186A Cited
US4533214A Cited
JPS60146224A Cited
JPS60175030A Cited
JPS6146928A Cited
US4852976A Cited
US4844569A Cited

USPTO Annuity & Maintenance Windows

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

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