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EP0586014A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Optical modulation device

Assignee: Koninklijke Philips NV
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Filing: 1993-08-30
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Granted: —
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Expires: 2013-08-30
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Abstract

Abstract An optical modulation device is described, which comprises two substrates, which are provided with at least one electrode, and an optically active layer situated between said two substrates, the optically active layer comprising a liquid crystalline material having ferroelectric, antiferroelectric or electroclinic properties. In accordance with the invention, the device is characterized in that the optically active layer comprises a permanently oriented anisotropic network of polymerized material containing free molecules of a chiral liquid crystalline material. Said network is preferably composed of a polymer formed from reactive monomers comprising at least two reactive groups on the basis of acrylates, methacrylates, epoxy compounds and/or thiolene systems. By means of such an optical modulation device grey levels which can be passively maintained for a relatively long period of time can be obtained in a relatively simple manner. In addition, the device in accordance with the invention is little sensitive to shocks. Besides, the device in accordance with the invention can be constructed so as to comprise a relatively thick optically active layer, without the occurrence of a disturbing loss of contrast caused by "chevrons".

Inventors

  • 👤 Rifat Ata Mustafa Hikmet

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-29 15:00
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/02; C09K19/0266; C09K19/0225; C09K19/0233; C09K19/52; C09K19/54; C09K19/542; C09K19/544; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/139; G02F1/141; C09K2019/546; G02F1/13775; G02F1/1412; G02F1/1418; G02F2203/00; G02F2203/30

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 67 words
An optical modulation device comprising two substrates, which are provided with at least one electrode, and an optically active layer which is located between said two substrates, the optically active layer comprising a liquid crystalline material having ferroelectric, antiferroelectric or electroclinic properties, characterized in that the optically active layer comprises a permanently oriented anisotropic network of polymerized material containing free molecules of a chiral liquid crystalline material.
Claim 2
Dependent Claim 24 words
A modulation device as claimed in Claim 1, characterized in that 5 to 60 wt.% of the active layer consists of an anisotropic network.
Claim 3
Dependent Claim 41 words
A modulation device as claimed in Claim 1 or 2, characterized in that the network is composed of a polymer formed from reactive monomers having at least two reactive groups on the basis of acrylates, methacrylates, epoxy compounds and/or thiolene systems.
Claim 4
Dependent Claim 45 words
A modulation device as claimed in Claim 1, 2 or 3, characterized in that the free molecules of the chiral liquid crystalline material in the active layer comprise one or more than one of the compounds in accordance with formulae 1-7 of the formula sheet.
Claim 5
Dependent Claim 25 words
A modulation device as claimed in one of the preceding Claims, characterized in that the chiral liquid crystalline material comprises free molecules having dichroic properties.
Claim 6
Dependent Claim 27 words
A modulation device as claimed in Claim 1-4, characterized in that the anisotropic network and the free molecules of the chiral liquid crystalline material exhibit dichroic properties.
Claim 7
Dependent Claim 41 words
A modulation device as claimed in one of the preceding Claims, in the form of a display device, comprising two substrates which are provided with a number of electrodes and an optically active layer which is located between said two substrates.

References Cited (Backward Citations)

JPS62260841A Cited
EP0313053A2 Cited
EP0451905A1 Cited
JPH0429219A Cited
WO1992004421A1 Cited
EP0506176A1 Cited

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