EP0488116A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Polymer dispersed liquid crystal display element and method of fabricating the same
Assignee: Seiko Epson Corp
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Filing: 1991-11-25
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Granted: —
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Expires: 2011-11-25
Abstract
Abstract Disclosed is a polymer dispersed liquid crystal display element designed in such a way that when an electric field is applied to a layer having a liquid crystal and a polymer mutually dispersed to cause phase separation thereof, the liquid crystal and polymer are aligned in the same direction. Also disclosed is a method of fabricating the liquid crystal display element, which mixes the polymer or polymer precursor, when in a liquid crystal phase, with the liquid crystal, aligns the liquid crystal and the polymer or the polymer precursor, and then hardens the polymer or polymer precursor.
Inventors
- 👤 Hidekazu Kobayashi
- 👤 Kiyohiro Samizu
- 👤 Jin Jei Wu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 12:59
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/13725; C; C09; C09K; C09K19/00; C09K19/04; C09K19/38; C09K19/3833; C09K19/3842; C09K19/3852; C09K19/52; C09K19/54; C09K19/542; C09K19/544; G02F1/133; G02F1/1333; G02F1/1334; G02F1/13345; G02F1/13347; G02F1/1335; G02F1/13363; G02F1/133638; G02F1/1347; G02F2203/00; G02F2203/02
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
69 words
A polymer dispersed liquid crystal display element comprising a liquid crystal polymer composite layer having a liquid crystal and a polymer mutually dispersed and phase-separated from each other, light scattering state occurring when said liquid crystal is aligned in the direction of an electric field upon application thereof, characterized in that said liquid crystal and said polymer are aligned in the same direction when no electric field is applied.
Claim 2
Dependent Claim
34 words
A liquid crystal display element according to claim 1, characterized in that said liquid crystal polymer composite layer is sandwiched between two substrates each having a transparent electrode provided on an inner surface thereof.
Claim 3
Dependent Claim
45 words
A liquid crystal display element according to claim 1, characterized in that said liquid crystal polymer composite layer is formed on a single substrate having a transparent electrode formed on a surface thereof, and has a top surface on which a transparent electrode is formed.
Claim 4
Dependent Claim
44 words
A liquid crystal display element according to claim 2 or 3, characterized in that said liquid crystal has a positive dielectric anisotropy, and said liquid crystal and said polymer are aligned in a direction parallel to said substrates when no electric field is applied.
Claim 5
Dependent Claim
44 words
A liquid crystal display element according to claim 2 or 3, characterized in that said liquid crystal has a negative dielectric anisotropy, and said liquid crystal and said polymer are aligned in a direction perpendicular to said substrates when applied with no electric field.
Claim 6
Dependent Claim
65 words
A liquid crystal display element according to claim 4, characterized in that said inner surface of said substrate or at least one of said two substrates, respectively, is subjected to such an alignment process as to align said liquid crystal and said polymer in a liquid crystal phase or a polymer precursor, which becomes a polymer when polymerized, in a direction parallel to said substrate.
Claim 7
Dependent Claim
66 words
A liquid crystal display element according to claim 5, characterized in that said inner surface of said substrate or of at least one of said two substrates, respectively, is subjected to such an alignment process as to align said liquid crystal and said polymer in a liquid crystal phase or a polymer precursor, which becomes a polymer when polymerized, in a direction perpendicular to said substrate.
Claim 8
Dependent Claim
97 words
A liquid crystal display element according to claim 2, characterized in that one of said two substrates is subjected to such an alignment process as to align said liquid crystal and said polymer in a liquid crystal phase or a polymer precursor, which becomes a polymer when polymerized, in a direction parallel to said substrate, and the other substrate is subjected to such an alignment process as to align said liquid crystal and said polymer in a liquid crystal phase or a polymer precursor, which becomes a polymer when polymerized, in a direction perpendicular to said substrate.
Claim 9
Dependent Claim
27 words
A liquid crystal display element according to claim 6, 7 or 8, characterized in that an alignment film is formed on said substrate as said alignment process.
Claim 10
Dependent Claim
38 words
A liquid crystal display element according to claim 2 or 3, characterized in that one of said two substrates or that said one substrate has an electrode serving as a reflection film formed on an inner surface thereof.
Claim 11
Dependent Claim
30 words
A liquid crystal display element according to claim 2 or 3, characterized in that one of said two substrates or that said substrate is additionally provided with a reflection film.
Claim 12
Dependent Claim
29 words
A liquid crystal display element according to any one of claims 1 to 11, characterized in that said liquid crystal is a nematic liquid crystal containing a chiral component.
Claim 13
Dependent Claim
23 words
A liquid crystal display element according to any one of claims 1 to 11, characterized in that said liquid crystal contains dichroic dye.
Claim 14
Dependent Claim
28 words
A liquid crystal display element according to any one of claims 1 to 13, characterized in that said polymer consists of a polymer containing a biphenyl side chain.
Claim 15
Dependent Claim
33 words
A liquid crystal display element according to any one of claims 1 to 14, characterized in that said polymer is of an ultraviolet-hardened type, of a heat-hardened type, or of a thermoplastic type.
Claim 16
Dependent Claim
24 words
A liquid crystal display element according to any one of claims 1 to 13, characterized in that said polymer is a polymer liquid crystal.
Claim 17
Dependent Claim
33 words
A liquid crystal display element according to any one of claims 1 to 16, characterized in that said polymer has a cosolvent, and has a liquid crystal phase in a solution phase state.
Claim 18
Dependent Claim
39 words
A liquid crystal display element according to any one of claims 1 to 13, characterized in that said polymer is formed by polymerization of at least two types of polymer precursors having a polymer portion and an aromatic ring.
Claim 19
Dependent Claim
34 words
A liquid crystal display element according to claim 18, characterized in that at least one of said polymer precursors contains a mesogen portion or fluorine atoms on a side chain accompanying a mesogen portion.
Claim 20
Dependent Claim
32 words
A liquid crystal display element according to claim 18, characterized in that at least one of said polymer precursors has a mesogen portion containing naphthalene, phenyl or biphenyl and a dielectric thereof.
Claim 21
Dependent Claim
23 words
A liquid crystal display element according to claim 18, characterized in that said polymer precursors are polymerized to be hardened by ultraviolet rays.
Claim 22
Dependent Claim
31 words
A liquid crystal display element according to claim 10 or 11 , characterized in that a phase-shift plate is disposed between said liquid crystal polymer composite layer and said reflection layer.
Claim 23
Dependent Claim
36 words
A liquid crystal display element according to claim 22, characterized in that an optical axis of said phase-shift plate forms an angle of 45 degrees with said aligning direction of said liquid crystal polymer composite layer.
Claim 24
Dependent Claim
19 words
A liquid crystal display element according to claim 22, characterized in that said phase-shift plate is a quarter-wave plate.
Claim 25
Dependent Claim
24 words
A liquid crystal display element according to claim 22, characterized in that said phase-shift plate has a transparent electrode formed on a surface thereof.
Claim 26
Dependent Claim
27 words
A liquid crystal display element according to claim 10 or 11 , characterized in that said reflection layer is formed on a surface of a phase-shift plate.
Claim 27
Dependent Claim
53 words
A liquid crystal display element according to any of claims 1 to 26, characterized in that two polymer dispersed liquid crystal display elements in each of which said aligning directions of said liquid crystal and polymer in said liquid crystal polymer composite layer intersect each other perpendicularly are placed one on the other.
Claim 28
Dependent Claim
37 words
A liquid crystal display element according to claim 1, characterized in that said aligning direction of said polymer is perpendicular to a plane including a normal line of said substrates and an optical axis of incident light.
Claim 29
Dependent Claim
30 words
A liquid crystal display element according to claim 28, characterized in that a polarizing plate and a reflector plate are disposed on a back surface of each of said substrates.
Claim 30
Dependent Claim
35 words
A liquid crystal display element according to claim 28, characterized in that a phase correcting plate, a light attenuating plate and a reflector plate are disposed on a back surface of each of said substrates.
Claim 31
Independent Claim
80 words
A method of fabricating a polymer dispersed liquid crystal display element, characterized by comprising the steps of: heating a liquid crystal and a thermoplastic polymer to cause said liquid crystal and said polymer to be dissolved into each other to be mixed together and aligning said liquid crystal and said polymer in the same direction; and cooling the resultant structure to harden said polymer, thereby causing phase separation between said liquid crystal and said polymer while maintaining the aligned state.
Claim 32
Independent Claim
87 words
A method of fabricating a polymer dispersed liquid crystal display element, characterized by comprising the steps of: heating a liquid crystal and a polymer precursor to cause said liquid crystal and said polymer precursor to be dissolved into each other to be mixed together and aligning said liquid crystal and said polymer precursor in the same direction in a liquid crystal phase; and polymerizing said polymer precursor to yield a polymer, thereby causing phase separation between said liquid crystal and said polymer while maintaining the aligned state.
Claim 33
Dependent Claim
83 words
A method according to claim 31 or 32, characterized in that after said liquid crystal and said thermoplastic polymer are dissolved into each other and either coated on one transparent substrate having a transparent electrode, or sealed between two transparent substrates having transparent electrodes, said liquid crystal and said polymer are aligned in the same direction, and then the resultant structure is cooled to harden said polymer, thereby causing phase separation between said liquid crystal and said polymer while maintaining the aligned state.
Claim 34
Dependent Claim
88 words
A method according to claim 31 or 32, characterized in that after said liquid crystal and said polymer precursor are dissolved into each other and either coated on one transparent substrate having a transparent electrode or sealed between two transparent substrates having transparent electrodes, said liquid crystal and said polymer precursor are aligned in the same direction in a liquid crystal phase, and then said polymer precursor is polymerized to be polymer, thereby causing phase separation between said liquid crystal and said polymer while maintaining the aligned state.
Claim 35
Dependent Claim
38 words
A method of claim 31 or 32, characterized in that the speed for phase separation is adjusted under a condition of a particle size of 0.1 to 10 µm that permits said polymer to cause best light scattering.
Claim 36
Dependent Claim
102 words
A method according to claim 33, characterized in that after at least one of inner surfaces of said two transparent substrates is subjected to an alignment process to align said liquid crystal and said thermoplastic polymer in a direction parallel or perpendicular to said substrate, said liquid crystal and said polymer are dissolved into each other and sealed between said two transparent substrates, said liquid crystal and said polymer are aligned in the same direction, and then the resultant structure is cooled to harden said polymer, thereby causing phase separation between said liquid crystal and said polymer while maintaining the aligned state.
Claim 37
Dependent Claim
97 words
A method according to claim 33, characterized in that after a surface of said transparent substrate is subjected to an alignment process to align said liquid crystal and said thermoplastic polymer in the same direction in a liquid crystal phase, said liquid crystal and said thermoplastic polymer are dissolved into each other and coated on said transparent substrate, said liquid crystal and said polymer are aligned in the same direction, and then the resultant structure is cooled to harden said polymer, thereby causing phase separation between said liquid crystal and said polymer while maintaining the aligned state.
Claim 38
Independent Claim
111 words
A method of fabricating a polymer dispersed liquid crystal display element, comprising the steps of: subjecting at least one of inner surfaces of two transparent substrates having transparent electrodes to align a liquid crystal and a polymer precursor in a direction parallel or perpendicular to said substrate; dissolving said liquid crystal and said polymer precursor into each other and sealing the resultant solution between said two transparent substrates; aligning said liquid crystal and said polymer precursor in the same direction in a liquid crystal phase; and polymerizing said polymer precursor to yield a polymer, characterized by causing phase separation between said liquid crystal and said polymer while maintaining the aligned state.
Claim 39
Independent Claim
107 words
A method of fabricating a polymer dispersed liquid crystal display element, comprising the steps of: subjecting a surface of one transparent substrate having a transparent electrode to align a liquid crystal and a polymer precursor in a direction parallel or perpendicular to said substrate; dissolving said liquid crystal and said polymer precursor into each other and coating the resultant solution on said transparent substrate; aligning said liquid crystal and said polymer precursor in the same direction in a liquid crystal phase; and polymerizing said polymer precursor to yield a polymer, characterized by causing phase separation between said liquid crystal and said polymer while maintaining the aligned state.
Claim 40
Dependent Claim
43 words
A method according to claim 32, characterized in that a dielectric of ester methacrylate of biphenyl methanol, ester acrylate, or a compound thereof, or a dielectric of ester methacrylate of naphthol, ester acrylate, or a compound thereof is used as said polymer precursor.
Claim 41
Dependent Claim
35 words
A method according to claim 40, characterized in that a mixture of said ester and a dielectric of ester methacrylate of biphenyl methanol, or a dielectric of ester acrylate is used as said polymer precursor.
References Cited (Backward Citations)
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