US6177216B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color filter layer of cholesterically ordered material, and reflective LCD provided with such a color filter layer
Assignee: US Philips Corp
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Filing: 1999-11-29
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Granted: 2001-01-23
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Expires: 2019-11-29
Abstract
Abstract The invention relates to a color filter layer of a cholesterically ordered material, in which the axis of the molecular helix is directed perpendicularly to said layer. According to the invention, the color filter layer comprises at least one dye which is able to absorb undesired colors caused by color shifts. A correct choice of the bandwidth of the primary colors of the color filter layer and the dyes significantly alleviates the problem of undesired color shift. The invention also relates to a liquid crystal color display device of the reflective type, which is provided with such a color filter layer.
Inventors
- 👤 Dirk J. Broer
- 👤 Grietje N. Mol
- 👤 Frans Leenhouts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:12
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133509; G02F1/133514; G02F1/133516; G02B; G02B5/00; G02B5/30; G02B5/3016; G02F1/133553
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
47 words
A color filter layer of a cholesterically ordered material, in which the axis of the molecular helix of the cholesteric material extends transversely to the layer, characterized in that the color filter layer also comprises one or more dyes which absorb unwanted colors caused by color shifts.
Claim 2
Dependent Claim
47 words
A color filter layer of a cholesterically ordered material, in which the axis of the molecular helix of the cholesteric material extends transversely to the layer, characterized in that the color filter layer also comprises one or more dyes which absorb unwanted colors caused by color shifts.
Claim 3
Dependent Claim
21 words
A color filter layer as claimed in claim 1 , characterized in that the cholesterically ordered material comprises a polymer network.
Claim 4
Dependent Claim
41 words
A color filter layer as claimed in claim 2 , characterized in that the pitch of the molecular helix is varied in such a way that the difference between the maximum pitch and the minimum pitch is at least 20 nm.
Claim 5
Dependent Claim
24 words
A color filter layer as claimed in claim 2 , characterized in that the dye(s) is (are) incorporated in the network via chemical bonds.
Claim 6
Dependent Claim
86 words
A liquid crystal color display device of the reflective type, comprising two substantially parallel substrates provided with an electrode layer and an orientation layer between which a layer of liquid crystalline material is present, one substrate being provided with a broadband absorption layer, a patterned color filter layer of cholesterically ordered material, and a ¼λ layer, and the other substrate being provided with a polarizer, characterized in that the color filter layer also comprises one or more dyes which absorb unwanted colors caused by color shifts.
Claim 7
Dependent Claim
86 words
A liquid crystal color display device of the reflective type, comprising two substantially parallel substrates provided with an electrode layer and an orientation layer between which a layer of liquid crystalline material is present, one substrate being provided with a broadband absorption layer, a patterned color filter layer of cholesterically ordered material, and a ¼λ layer, and the other substrate being provided with a polarizer, characterized in that the color filter layer also comprises one or more dyes which absorb unwanted colors caused by color shifts.
Claim 8
Dependent Claim
27 words
A display device as claimed in claim 5 , characterized in that the dyes are mixed with the cholesterically ordered material of the patterned color filter layer.
Claim 9
Dependent Claim
47 words
A display device as claimed in claim 5 , characterized in that the cholesterically ordered material of the color filter layer is polymerized to a polymer network, with the difference between the maximum pitch and the minimum pitch of the molecular helix being at least 20 nm.
Claim 10
Dependent Claim
22 words
A display device as claimed in claim 7 , characterized in that the dyes are incorporated in the network via chemical bonds.
Claim 11
Dependent Claim
20 words
A display device as claimed in claim 5 , characterized in that the cholesterically ordered material has a focal-conic texture.
Claim 12
Dependent Claim
27 words
A display device as claimed in claim 9 , characterized in that the dyes are incorporated in the form of dispersed segments in the color filter layer.
References Cited (Backward Citations)
EP0600349A1
Cited
US5506704A
Cited
US5793456A
Cited
US5682212A
Cited
JPH07239471A
Cited
US5683622A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-01-23 | 2004-07-24 | 2005-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-01-23 | 2008-07-24 | 2009-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-01-23 | 2012-07-24 | 2013-01-23 | $7700.00 | Window Closed / Lapsed |