US4984874A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal display device having retardation films
Assignee: Toshiba Corp
•
Filing: 1989-07-07
•
Granted: 1991-01-15
•
Expires: 2009-07-07
Abstract
Abstract A liquid crystal cell includes first and second substrates arranged to oppose each other, first and second electrodes formed on opposing surfaces of the first and second substrates, respectively, and a liquid crystal composition filled between the first and second substrates and arranged in a twisted mode. First and second polarizers are arranged on both sides of the liquid crystal cell. A first optical retardation film is arranged between the first substrate and the first polarizer, and a second optical retardation film is arranged between said second substrate and said second polarizer. The liquid crystal cell has a retardation value R0 of 0.4 to 0.85 μm, defined by an equation: Δn·d·cos.sup.2 θ where d is a distance between the first and second substrates, Δn is an optical anisotropy of the liquid crystal composition and θ is a tilt angle of the liquid crystal composition.
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
2026-10-26 20:36
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; G02F2413/02; G02F2413/08
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
178 words
A liquid crystal display device comprising: (A) a liquid crystal cell including: (a) first and second substrates arranged to oppose each other, (b) first and second electrodes formed on opposing surfaces of said first and second substrates, respectively, and (c) a liquid crystal composition filled between said first and second substrates and arranged in a twisted mode; (B) first and second polarizers arranged on both sides of said liquid crystal cell; (C) a first optical retardation film arranged between said first substrate and said first polarizer; and (D) a second optical retardation film arranged between said second substrate and said second polarizer; wherein said liquid crystal cell has a retardation value R0 of 0.4 to 0.85 μm, defined by an equation: Δn·d·cos.sup.2 θ where d is a distance between said first and second substrates, Δn is an optical anistropy of said liquid crystal composition and θ is a tilt angle of said liquid crystal composition; and wherein a retardation value of each of said first and second optical retardation films falls within a range of R0×0.3 to R0×1.0.
Claim 2
Dependent Claim
178 words
A liquid crystal display device comprising: (A) a liquid crystal cell including: (a) first and second substrates arranged to oppose each other, (b) first and second electrodes formed on opposing surfaces of said first and second substrates, respectively, and (c) a liquid crystal composition filled between said first and second substrates and arranged in a twisted mode; (B) first and second polarizers arranged on both sides of said liquid crystal cell; (C) a first optical retardation film arranged between said first substrate and said first polarizer; and (D) a second optical retardation film arranged between said second substrate and said second polarizer; wherein said liquid crystal cell has a retardation value R0 of 0.4 to 0.85 μm, defined by an equation: Δn·d·cos.sup.2 θ where d is a distance between said first and second substrates, Δn is an optical anistropy of said liquid crystal composition and θ is a tilt angle of said liquid crystal composition; and wherein a retardation value of each of said first and second optical retardation films falls within a range of R0×0.3 to R0×1.0.
Claim 3
Dependent Claim
19 words
The device according to claim 1, wherein said first and second optical retardation films have the same retardation value.
Claim 4
Dependent Claim
36 words
The device according to claim 1, wherein said first substrate and said first optical retardation film are provided by one member, or said second substrate and said second optical retardation film are provided by one member.
References Cited (Backward Citations)
EP0089493A1
Cited
GB2171549A
Cited
US4852976A
Cited
EP0239433A1
Cited
US4909606A
Cited
EP0246842A2
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 |