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US 2003/0148043 A1Published application
STN liquid crystal display
AssigneeMerck Patent GmbH
InventorHarald Hirschmann
Life of this patent
Estimating the term…
Abstract
The invention relates to supertwist liquid-crystal displays (SLCDs) having very short response times and good steepnesses and angular dependences and to the novel nematic liquid-crystal mixtures employed therein, which are distinguished by the fact that they comprise at least one compound of the formula IA 1 and at least one compound of the formula IB 2 and/or at least one compound of the formula IC 3 in which Ra, Rb, Rc, Rd, Re, Y1, Y2, Y3, Y4, q and p are as defined above.
Claims13
A supertwist liquid-crystal display comprising
- two outer plates which, together with a frame, form a cell,
- a nematic liquid-crystal mixture of positive dielectric anisotropy present in said cell,
- electrode layers with alignment layers on the insides of said outer plates,
- a pretilt angle between the longitudinal axis of the molecules at the surface of said outer plates and said outer plates of 0 to 30 degrees, and
- a twist angle of the liquid-crystal mixture in the cell from alignment layer to alignment layer with a value of 22.5° to 600°, and
- said nematic liquid-crystal mixture comprises
- a) 0-60% by weight of a liquid-crystalline component A comprising one or more compounds having a dielectric anisotropy of greater than +1.5;
- b) 0-60% by weight of a liquid-crystalline component B comprising one or more compounds having a dielectric anisotropy of between −1.5 and +1.5;
- c) 0-20% by weight of a liquid-crystalline component D comprising one or more compounds having a dielectric anisotropy of below −1.5;
- and
- d) optionally an optically active component C in an amount whereby the ratio between the layer thickness (separation of the outer plates) and the natural pitch of the resultant chiral nematic liquid-crystal mixture is 0.2 to 1.3,
- wherein liquid-crystal mixture contains at least one compound of formula IA
- 85
- in which
- Ra is H or an alkyl group having 1 to 7 carbon atoms,
- and
- Rb is an alkyl or alkoxy group having 1 to 10 carbon atoms or an alkenyl or alkenyloxy group having 2 to 10 carbon atoms;
- and at least one compound of formula IB, at least one compound of formula IC or at least one compound of formula IB and at least one compound of formula IC
- 86
- wherein
- Rc is H or an alkyl group having 1 to 7 carbon atoms,
- Rd is F, OCF3, OCHF2, an alkyl or alkoxy group having 1 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms,
- Re is an alkyl or alkoxy group having 1 to 10 carbon atoms or an alkenyl or alkenyloxy group having 2 to 10 carbon atoms,
- Y1 to Y4 are each, independently of one another, H or F,
- q is 0 or 1, and
- p is 0, 1 or 2.
23 more elements
A liquid-crystal mixture comprising:
- a) 0-60% by weight of a liquid-crystalline component A comprising one or more compounds having a dielectric anisotropy of greater than +1.5;
- b) 0-60% by weight of a liquid-crystalline component B comprising one or more compounds having a dielectric anisotropy of between −1.5 and +1.5;
- c) 0-20% by weight of a liquid-crystalline component D comprising one or more compounds having a dielectric anisotropy of below −1.5;
- and
- d) optionally an optically active component C in an amount whereby the ratio between the layer thickness (separation of the outer plates) and the natural pitch of the resultant, chiral nematic liquid-crystal mixture is 0.2 to 1.3,
- wherein liquid-crystal mixture additionally comprises at least one compound of formula IA
- 99
- in which
- Ra is H or an alkyl group having 1 to 7 carbon atoms,
- and
- Rb is an alkyl or alkoxy group having 1 to 10 carbon atoms or an alkenyl or alkenyloxy group having 2 to 10 carbon atoms;
- and at least one compound of formula IB, at least one compound of formula IC or at least one compound of formula IB and at least one compound of formula IC
- 100
- wherein
- Rc is H or an alkyl group having 1 to 7 carbon atoms,
- Rd is F, OCF3, OCHF2, an alkyl or alkoxy group having 1 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms,
- Re is an alkyl or alkoxy group having 1 to 10 carbon atoms or an alkenyl or alkenyloxy group having 2 to 10 carbon atoms,
- Y1 to Y4 are each, independently of one another, H or F,
- q is 0 or 1, and
- p is 0, 1 or 2.
17 more elements
Dependencies are inferred from the claim text.