US5650833A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal display device having birefringent films with nx >n.sub. >ny
Assignee: AGC Inc
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Filing: 1996-04-01
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Granted: 1997-07-22
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Expires: 2016-04-01
Abstract
Abstract The liquid crystal display device of the present invention comprises a liquid crystal layer of a nematic liquid crystal having positive dielectric anisotropy and including a chiral material, the liquid crystal layer being interposed between a pair of substrates with transparent electrodes each having an aligning layer which are arranged substantially in parallel to provide a twist angle of 160 DEG -300 DEG , a driving means to apply a voltage across the electrodes attached to the substrates which interpose the liquid crystal layer, a pair of polarizing plates arranged outside the liquid crystal layer, and at least one birefringent plate provided between the liquid crystal layer and the polarizing plate at at least one side of the liquid crystal layer, wherein the product DELTA n1xd, of the anisotropy of refractive index DELTA n, of liquid crystal molecules in the liquid crystal layer and the thickness d, of the liquid crystal layer is in a range of 0.4-1.5 mu m, and three main refractive indices nx, ny and nz of the birefringent plate are in a relation of nx>/=nz</=ny where nx and ny respectively represent the refractive indices in the direction of film plane of the birefringent plate (provided nx>ny) and nz represents the refractive index in the direction of film thickness of the birefringent plate.
Inventors
- 👤 Minoru Akatsuka
- 👤 Yuji Sohda
- 👤 Kazutoshi Sawada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:50
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/13363; G02F1/133634; G02F1/137; G02F1/139; G02F1/1396; G02F1/1397
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
241 words
A liquid crystal display device comprising a liquid crystal layer of a nematic liquid crystal having positive dielectric anisotropy and including a chiral material, said liquid crystal layer being interposed between a pair of substrates with transparent electrodes each having an aligning layer which are arranged substantially in parallel to provide a twist angle of 160°-300°, a driving means to apply a voltage across the electrodes attached to the substrates which interpose the liquid crystal layer, a pair of polarizing plates arranged outside the liquid crystal layer, and at least one birefringent plate provided between the liquid crystal layer and the polarizing plate at at least one side of said liquid crystal layer, characterized in that the product Δn 1 ·d 1 of the anisotropy of refractive index Δn 1 of liquid crystal molecules in the liquid crystal layer and the thickness d 1 of the liquid crystal layer is in a range of 0.8-0.9 μm, and three main refractive indices n x , n y and n z of the birefringent plate are in a relation of n x >n z >n y and 0.0043≧(n x -n z )>0, where n x and n y respectively represent the refractive indices in the direction of film plane of the birefringent plate (provided n x >n y ) and n z represents the refractive index in the direction of film thickness of the birefringent plate said birefringent plate comprising a plastic film.
Claim 2
Dependent Claim
241 words
A liquid crystal display device comprising a liquid crystal layer of a nematic liquid crystal having positive dielectric anisotropy and including a chiral material, said liquid crystal layer being interposed between a pair of substrates with transparent electrodes each having an aligning layer which are arranged substantially in parallel to provide a twist angle of 160°-300°, a driving means to apply a voltage across the electrodes attached to the substrates which interpose the liquid crystal layer, a pair of polarizing plates arranged outside the liquid crystal layer, and at least one birefringent plate provided between the liquid crystal layer and the polarizing plate at at least one side of said liquid crystal layer, characterized in that the product Δn 1 ·d 1 of the anisotropy of refractive index Δn 1 of liquid crystal molecules in the liquid crystal layer and the thickness d 1 of the liquid crystal layer is in a range of 0.8-0.9 μm, and three main refractive indices n x , n y and n z of the birefringent plate are in a relation of n x >n z >n y and 0.0043≧(n x -n z )>0, where n x and n y respectively represent the refractive indices in the direction of film plane of the birefringent plate (provided n x >n y ) and n z represents the refractive index in the direction of film thickness of the birefringent plate said birefringent plate comprising a plastic film.
Claim 3
Dependent Claim
31 words
The liquid crystal device according to claim 1, wherein said birefringent plate is arranged between the liquid crystal layer and the polarizing plate at one side of the liquid crystal layer.
Claim 4
Dependent Claim
32 words
The liquid crystal display device according to claim 1, wherein said birefringent plate is arranged between the liquid crystal layer and the polarizing plate at each side of the liquid crystal layer.
Claim 5
Dependent Claim
27 words
The liquid crystal display device according to claim 1, wherein the refractive index of the birefringent plate is (n z -n y )/(n x -n y )>0.1.
Claim 6
Dependent Claim
18 words
The liquid crystal display device according to claim 1, wherein a color filter is formed in the cell.
Claim 7
Dependent Claim
19 words
The liquid crystal display device according to claim 5, wherein the filter is a color filter having three colors.
Claim 8
Dependent Claim
31 words
The liquid crystal display device according to claim 1, wherein each of the substrates with electrodes comprises a substrate, a color filter formed thereon and electrodes formed on the color filter.
Claim 9
Dependent Claim
26 words
The liquid crystal device according to claim 1, wherein two refractive indices n x ,n z are in a relation of 0.0028≧(n x -n z ).
Claim 10
Dependent Claim
26 words
The liquid crystal device according to claim 1, wherein two refractive indices n x ,n z are in a relation of 0.0024≧(n x -n z ).
Claim 11
Dependent Claim
26 words
The liquid crystal device according to claim 1, wherein two refractive indices n x ,n z are in a relation of (n y -n z )≧0.0007.
Claim 12
Dependent Claim
26 words
The liquid crystal device according to claim 1, wherein two refractive indices n x ,n z are in a relation of 0.0028≧(n x -n z )≧0.0007.
Claim 13
Dependent Claim
26 words
The liquid crystal device according to claim 1, wherein two refractive indices n x ,n z are in a relation of 0.0024≧(n x -n z )≧0.0007.
References Cited (Backward Citations)
US5056896A
Cited
US5189538A
Cited
US5142393A
Cited
US5016988A
Cited
US5369513A
Cited
US5523867A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-07-21 | 2001-01-20 | 2001-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-07-21 | 2005-01-20 | 2005-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-07-21 | 2009-01-20 | 2009-07-22 | $7700.00 | Window Closed / Lapsed |