EP0044666A2
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EP
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Helichromic compounds and displays
Assignee: 3M Co
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Filing: 1981-07-08
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Granted: —
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Expires: 2001-07-08
Abstract
Abstract A composition for use with liquid crystal compositions in liquid crystal display devices, which possesses both a chromophoric moiety and a helical ordering moiety. The helical ordering moiety is capable of helically ordering a mixture of liquid crystal material and helichromic compound. The helichromic compound can be utilized in conventional "guest-host" and "twist nematic" displays as well as in unique helichromic displays. When used in helichromic displays, the helichromic compounds eliminate after-image scattering and enable the display to be operated at reduced voltages.
Inventors
- 👤 Harvey A. Brown
- 👤 William A. Huffman
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 11:29
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/04; C09K19/36; C09K19/52; C09K19/54; C09K19/60; C09K19/601; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/135
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
59 words
An organic, nonionic, helichromic compound characterized in that it has the general formula Q is an organic group having a dichroic character; Z is an organic group having a helical ordering character capable of helically ordering a mixture of nematic liquid crystal material and said helichromic compound; and -n is an integer having a value of 1 or greater.
Claim 2
Dependent Claim
59 words
An organic, nonionic, helichromic compound characterized in that it has the general formula Q is an organic group having a dichroic character; Z is an organic group having a helical ordering character capable of helically ordering a mixture of nematic liquid crystal material and said helichromic compound; and -n is an integer having a value of 1 or greater.
Claim 3
Dependent Claim
20 words
The helichromic compound of Claim 1 further characterized in that Z is an organic group having an asymmetric carbon atom.
Claim 4
Dependent Claim
39 words
The helichromic compound of Claim 2 further characterized in that Z is selected from the group consisting of a (+)-2-methylalkyl group, a (+) - 3-methylalkyl group, a (+)-citronellyl group, a (+)-camphanyl group, a (+)-3-methylcyclohexyl group, and a (+)-a-methylbenzyl group.
Claim 5
Dependent Claim
34 words
The helichromic compound of Claim 1 further characterized in that Q is a radical selected from the group consisting of azo, azo-stilbene, benzothiazolyl polyazo, methine, azo-methine, merocyanine, methine arylidene and anthraquinone heterocyclic dicarboximide radicals.
Claim 6
Dependent Claim
21 words
A composition comprising a nematic liquid crystal material characterized in that in admixture therewith is the helichromic compound of Claim 1.
Claim 7
Dependent Claim
36 words
The composition of Claim 5 further characterized in that said helichromic compound is present in an amount effective to provide helical ordering of said composition when said composition is used in a liquid crystal display device.
Claim 8
Dependent Claim
45 words
The composition nf Claim 5 further characterized in that said helichromic compound is present in an amount ineffective to helically order said composition, but effective to provide said composition with the ability to substantially absorb polarized light when used in a liquid crystal display device.
Claim 9
Dependent Claim
62 words
The composition of Claim 5 further characterized in that said helichromic compound is present in an amount ineffective to helically order said composition, and ineffective to provide said composition with the ability to substantially absorb polarized light, but effective to eliminate the hydrodynamic effect of optical bounce, and reduce decay time when said composition is used in a liquid crystal display device.
Claim 10
Dependent Claim
57 words
A liquid crystal display device which is responsive to the absence or presence of an electric field, said device comprising a layer of a nematic liquid crystal material and two conductive electrodes positioned, respectively, adjacent opposing surfaces of said layer, characterized in that in admixture with said liquid crystal material is the helichromic compound of Claim 1.
Claim 11
Dependent Claim
78 words
The device of Claim 9 further characterized in that said helichromic compound is present in an amount effective to provide helical ordering of said mixture of liquid crystal material and helichromic compound, and to induce in said helically ordered mixture a pitch which is effective to allow said mixture to substantially absorb unpolarized light incident thereon in the absence of an electric field and to substantially transmit unpolarized light incident thereon in the presence of an electric field.
Claim 12
Dependent Claim
78 words
The device of Claim 9 wherein said device additionally comprises one auxiliary polarizer and further characterized in that said helichromic compound is present in an amount ineffective to helically order said mixture of liquid crystal material and helichromic compound, but effective to provide said mixture with the ability to substantially absorb polarized light incident thereon in the absence of an electric field, and to substantially transmit said polarized light incident thereon in the presence of an electric field.
Claim 13
Dependent Claim
75 words
The device of Claim 9 wherein said device additionally comprises two auxiliary polarizers and further characterized in that said helichromic compound is present in an amount: ineffective to helically order said mixture of crystal material and helichromic compound; and ineffective to provide said mixture with the ability to substantially absorb polarized light incident thereon in the absence of an electric field; but effective to eliminate the hydrodynamic effect of optical bounce, and rednce decay time.
References Cited (Backward Citations)
No citation records indexed.
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