Polymer Network Liquid Crystal Patents (Class 349/88)
  • Patent number: 6133975
    Abstract: A liquid crystal display device including a polyimide alignment layer, having a bistable liquid crystal material and a polymer stabilizer in an amount effective to stabilize the liquid crystal, preferably about 2 weight percent, associated with the liquid crystal material, the liquid crystal having a low pretilt angle, to eliminate stripe tendency and to increase hysteresis. The device has a low driving voltage, low power consumption and fast switching.
    Type: Grant
    Filed: May 7, 1997
    Date of Patent: October 17, 2000
    Assignee: Kent State University
    Inventors: Jianlin Li, Philip J. Bos
  • Patent number: 6128056
    Abstract: A liquid crystal display element includes a polymer liquid crystal composite layer in which liquid crystal droplets are dispersed and held in a continuous phase of matrix comprising polymer compound, or liquid crystals are dispersed and held in networks of matrix of a three dimensional network form comprising polymer compound. All areas of this polymer liquid crystal composite layer, except a non-active area, in which cracks will develop, in the vicinity of a sealant, is formed as an active area, so that, even when the cracks develop, stripy display unevenness caused by the cracks can be prevented from being visually confirmed on a display screen.
    Type: Grant
    Filed: February 2, 1999
    Date of Patent: October 3, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hirofumi Kubota, Kenji Nakao, Tsuyoshi Uemura
  • Patent number: 6122024
    Abstract: A switchable liquid crystal device, for instance for use as a reflective display, includes a cell containing a helical polymer network and a nematic liquid crystal. Electrodes are provided for applying a field across the cell so as to switch between different optical states. In a reflective state, the cell reflects incident light within a waveband which is relatively insensitive to temperature variations. The device is formed by filling the cell with the liquid crystal and polymer precursor material and then cross-linking or polymerising, for instance by photopolymerisation, the precursor material to form the helical polymer network.
    Type: Grant
    Filed: July 16, 1997
    Date of Patent: September 19, 2000
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Henning Molsen, Martin David Tillin, Tomoaki Kuratate
  • Patent number: 6108062
    Abstract: A liquid crystal optical device including a liquid crystal/polymer composite film including of a matrix polymer composed mainly of a transparent resin having an ionic dissociative group and, dispersed therein, a liquid crystal particle; and conductive substrates sandwiching the liquid crystal/polymer composite film therebetween, at least one of the conductive substrates being transparent.
    Type: Grant
    Filed: January 27, 1998
    Date of Patent: August 22, 2000
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventors: Satoshi Takeuchi, Masayuki Ando, Tatsuya Tabei, Tadafumi Shindo, Hiroki Maeda, Hideshi Hattori, Kei Ikegami
  • Patent number: 6108061
    Abstract: Monomers with photopolymerization characteristics and an initiator for polymerization are added to a liquid crystal composition having a ferroelectric liquid crystal phase (S5). In a state (S6) where coexist two domains which differ from each other in directions of molecular major axes in the ferroelectric liquid crystal phase, light is projected to the liquid crystal layer to form a polymer reticulate structure therein (S7). As a result, this state is made a stable one and the liquid crystal shows macroscopic switching behaviors among two states causing dark and bright displays respectively, and the above-described state causing halftone display.
    Type: Grant
    Filed: March 14, 1997
    Date of Patent: August 22, 2000
    Assignees: Sharp Kabushiki Kaisha, The Secretary of State for Defence in Her Britannic Majesty's Government of the Kingdom of Great Britain and Northern Ireland
    Inventors: Teiyu Sako, Aya Miyazaki, Akira Sakaigawa, Mitsuhiro Koden
  • Patent number: 6075583
    Abstract: In order to the effects of impact on liquid crystal devices a polymer network is introduced into ferroelectric liquid crystal cells. A liquid crystal device comprises two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, characterised in that the liquid crystal material contains a small amount of monomer. The liquid crystal material may also contain a photoinitiator. The monomer material may be cured to produce the polymer network; the curing may be carried out in the presence of an electric or magnetic field. Further, the monomer may be cured in an isotropic or liquid crystal phase.
    Type: Grant
    Filed: February 27, 1997
    Date of Patent: June 13, 2000
    Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventors: Ian Robert Mason, Damien Gerard McDonnell, John Clifford Jones, Guy Peter Bryan-Brown
  • Patent number: 6072552
    Abstract: A liquid crystal layer comprising a liquid crystal display has first and second liquid crystal gel layers orientated so that polymer threads are of fixed directions within a dichroic liquid crystal. The direction of orientation of the polymer threads included in the first liquid crystal gel layer and the direction of orientation of the polymer threads included in the second liquid crystal gel layer are orthogonal with respect to each other.
    Type: Grant
    Filed: April 2, 1998
    Date of Patent: June 6, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Shinichi Komura, Yuji Mori, Junichi Hirakata, Masahiko Ando, Osamu Itou, Ikuo Hiyama
  • Patent number: 6023312
    Abstract: An optical device employs a composite of a liquid crystalline substance and an orientation-sustaining material, such as a selected polymer, flat particles, or other material capable of sustaining the state of orientation of the liquid crystalline substance. The optical device has a memory function which is erased by the application of an electrical signal. External force for writing on the device generates local changes of the state of orientation of the liquid crystalline substance. The written display is memorized, and can be erased by the application of an electrical signal. When a two-frequency-driving liquid crystalline substance is used, the device has a long-term memory function. In this device, writing can be conducted at one frequency and erasure easily conducted at the other frequency. These optical devices can be used for light adjustment, display, and data storage.
    Type: Grant
    Filed: October 25, 1996
    Date of Patent: February 8, 2000
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventors: Naoki Hasegawa, Masaya Kawasumi, Arimitsu Usuki, Akane Okada
  • Patent number: 6018378
    Abstract: A composition for use in a liquid crystal optical element, such as a liquid crystal display or laser shutter device, comprised of a liquid crystal material and a solidified polymer material. The liquid crystal is such that its refractive index is changed depending on states of applying a voltage. In one state, the refractive index of the liquid crystal substantially coincides with the refractive index of the solidified matrix to thereby pass light. While in the other state, the refractive index of the liquid crystal does not coincide with the refractive index of the solidified matrix to thereby cause the scattering of light. Specifically, the liquid crystal material used in the composition has a refractive index anisotropy (.DELTA.n) is greater than 0.18 and the dielectric anisotropy (.DELTA..epsilon.) satisfies the relation of 5<.DELTA..epsilon.<11.6.
    Type: Grant
    Filed: December 18, 1997
    Date of Patent: January 25, 2000
    Assignee: Asahi Glass Company, Ltd.
    Inventors: Yoshinori Hirai, Satoshi Niiyama, Tomoki Gunjima, Masanori Yuki, Masaya Kunigita, Yukio Yoshikawa, Eiji Shidoji
  • Patent number: 6015507
    Abstract: A liquid crystal element includes a pair of plates at least one of which is transparent, and a composite layer retained between the plates and including a liquid crystal material in a transparent resin substrate.
    Type: Grant
    Filed: November 8, 1995
    Date of Patent: January 18, 2000
    Assignee: Minolta Co., Ltd.
    Inventors: Nobuyuki Kobayashi, Kiyofumi Hashimoto, Takuji Hatano
  • Patent number: 6014194
    Abstract: A liquid crystal display device comprises extended polymer networks formed in the liquid crystal cells. By adding a monomer and a photo-initiator into the liquid crystal material of a liquid crystal display, applying a bias voltage and exposing the display under a UV light, a polymer network can be formed. The polymer network modifies the electro-optical characteristic of a liquid crystal display device. With different bias voltages, polymer networks of different structures can be formed so that the color difference of the liquid crystal display with respect to red, green and blue light can be minimized. Liquid crystal display devices of fast switching response and low color dispersion can be fabricated.
    Type: Grant
    Filed: August 1, 1997
    Date of Patent: January 11, 2000
    Assignee: Industrial Technology Research Institute
    Inventors: Chen-Lung Kuo, Chung-Kuang Wei, Yong-Hong Lu
  • Patent number: 5993689
    Abstract: A polymer dispersed liquid crystal (PDLC) display element for use in an electronic apparatus wherein the display element operates in a PDLC mode or reverse PDLC mode providing for reduction of visual display haze, improved display contrast. The particular medium includes a liquid crystal portion and a polymer portion and may include a chiral component. In cases where visual display haze and contract is a particular problem in the utility of the reverse PDLC display element, such as in the case where the display element is combined with a solar battery, a sufficient amount of dichroic dye is added to the liquid crystal portion of the medium, and, further, a compound showing no fluorescence emission with respect to a liquid crystal portion, or a polymer or a chiral polymer precursor portion of the medium, is employed.
    Type: Grant
    Filed: February 12, 1997
    Date of Patent: November 30, 1999
    Assignee: Seiko Epson Corporation
    Inventors: Hidekazu Kobayashi, Eiji Chino, Masayuki Yazaki, Hidehito Iisaka
  • Patent number: 5959707
    Abstract: A nematic liquid crystal display includes a first substrate provided with a common electrode, a second substrate provided with a pixel electrode, the second substrate being arranged to extend in parallel to the first substrate, and a liquid crystal cell which includes a nematic liquid crystal with a splay distortion. In the liquid crystal domains of a first type which are different in tilted-up direction of liquid crystal molecules coexist, and domains of a second type which are different in twist direction of liquid crystal molecules coexist. The liquid crystal may include a polymer that is a polymerized monomer or oligomer.
    Type: Grant
    Filed: April 24, 1996
    Date of Patent: September 28, 1999
    Assignee: NEC Corporation
    Inventors: Hideya Murai, Masayoshi Suzuki
  • Patent number: 5948486
    Abstract: A method for the loading and alignment of liquid crystal polymers in electro-optic and electro-active devices by in-situ polymerization between substrates of liquid crystal monomers. The molecular weight of the resulting liquid crystal polymer is controlled by the addition of a chain transfer reagent, for example, a thiol-containing compound which may be a liquid crystal material.
    Type: Grant
    Filed: April 7, 1997
    Date of Patent: September 7, 1999
    Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventors: Ian Charles Sage, Mark Andrew Verrall, David Coates, Simon Greenfield
  • Patent number: 5936692
    Abstract: The invention relates to a multi-domain liquid-crystal display device comprising two substantially parallel substrates which are provided with an electrode layer and an orientation layer. A layer of a nematically ordered liquid-crystalline material comprising a chiral dopant is sandwiched between the substrates. The layer is structured in such a manner that the pixels of the layer are composed of at least two types of sub-pixels in which the twist senses of the liquid-crystalline material are mutually opposite. This construction in accordance with the invention is achieved by differentiating the composition of the chiral dopant in the different types of sub-pixels. This is attained by employing isomerizable chiral dopants and/or diffusion techniques in combination with local exposure of the liquid-crystal layer. The invention also provides methods of manufacturing such multi-domain liquid-crystal display devices.
    Type: Grant
    Filed: June 2, 1998
    Date of Patent: August 10, 1999
    Assignee: U.S. Philips Corporation
    Inventor: Peter Van De Witte
  • Patent number: 5903330
    Abstract: An optical component includes a substrate or cell having two spaced-apart substrates, one or more orientation layers on the substrates and one or more anisotropic layers of cross-linked liquid crystalline monomers or oligomers with locally different orientation of the liquid crystal molecules. The surfaces of the orientation layers adjacent the liquid crystalline layers have orientation patterns with a defined parallel or fan-like line structure in locally limited regions. The average spacing between the lines of the fan-like line structure is not greater than the thickness of the liquid crystal layer and the angle between neighboring lines is not greater than 3.degree..
    Type: Grant
    Filed: October 15, 1996
    Date of Patent: May 11, 1999
    Assignee: Rolic AG
    Inventors: Jurg Funfschilling, Martin Ruetschi, Martin Schadt, Hubert Seiberle
  • Patent number: 5847798
    Abstract: A new liquid crystalline light modulating cell and material are characterized by liquid crystalline light modulating material of liquid crystal and polymer, the liquid crystal being a chiral nematic liquid crystal having positive dielectric anisotropy and including chiral material in an amount effective to form focal conic and twisted planar textures, the polymer being distributed in phase separated domains in the liquid crystal cell in an amount that stabilizes the focal conic and twisted planar textures in the absence of a field and permits the liquid crystal to change textures upon the application of a field. In one embodiment, the material is light scattering in a field-OFF condition and optically clear in a field-ON condition, while in another embodiment, the material is optically clear in a field-OFF condition and light scattering in a field-ON condition.
    Type: Grant
    Filed: May 6, 1997
    Date of Patent: December 8, 1998
    Assignee: Kent State University
    Inventors: Deng-Ke Yang, Ruiqing Ma
  • Patent number: 5831700
    Abstract: A liquid crystalline light modulating pixel includes first and second cell wall structures and nematic liquid crystal within a UV cured polymer network disposed therebetween. The first and second cell wall structures cooperate with the liquid crystal to form four liquid crystal domains within the pixel. The liquid crystal in each of the domains exhibits a twisted nematic liquid crystal structure and the orientation of the liquid crystal director of the liquid crystal adjacent one of the cell wall structures in at least two domains is different. The polymer network stabilizes the four domain structure at both high field and zero field conditions.
    Type: Grant
    Filed: May 15, 1996
    Date of Patent: November 3, 1998
    Assignee: Kent State University
    Inventors: Jianlin Li, Philip J. Bos, Jianmin Chen
  • Patent number: 5812227
    Abstract: The liquid crystal device is constituted by disposing a display layer between a pair of electrode plates. The display layer comprises a porous polymer material having open pores partially filled and a low-molecular weight mesomorphic compound impregnating the porous polymer material. The display layer is free from an unfilled portion of the low-molecular weight mesomorphic compound to be effective for providing a liquid crystal device showing a high transmittance and a good contrast. The display layer also comprises a three dimensional network structure coated with a polymer layer, and a low-molecular weight mesomorphic compound impregnating the three-dimensional network structure. The display layer is free from a fibrous part which is unstable against an applied voltage to be effective for providing a liquid crystal device showing no hysteresis.
    Type: Grant
    Filed: April 1, 1993
    Date of Patent: September 22, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yomishi Toshida, Kazuo Yoshinaga, Toshikazu Ohnishi, Koichi Sato, Takeo Eguchi, Tsuyoshi Shibata
  • Patent number: 5796453
    Abstract: A liquid crystal display device includes a pair of substrates; a liquid crystal layer interposed between the pair of substrates; and an electrode for applying a voltage to the liquid crystal layer. The liquid crystal layer includes a polymer dispersed liquid crystal material having a polymer phase and a liquid crystal phase, and fulfills the conditions represented by:2.585.multidot.d.sup.(-1/3) -0.3<R<2.585.multidot.d.sup.(-1/3) +0.3where d represents the thickness of the liquid crystal layer in the unit of micrometers and R represents the characteristic length of the liquid crystal phase in the unit of micrometers.
    Type: Grant
    Filed: July 31, 1996
    Date of Patent: August 18, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kenji Nakao, Masao Yamamoto, Tsuyoshi Uemura
  • Patent number: 5784137
    Abstract: A liquid crystal display device includes substrates opposed to each other, a polymeric layer patterned into a predetermined pattern, and a liquid crystal layer at least partially surrounded by the polymeric layer. The polymeric layer and the liquid crystal layer are interposed between the substrates. The polymeric layer is at least partially formed by polymerizing a liquid crystalline polymerization precursor in a state where the molecules of the liquid crystalline polymerization precursor are aligned in a predetermined direction by an alignment regulating force of at least one of the substrates.
    Type: Grant
    Filed: February 16, 1996
    Date of Patent: July 21, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Makoto Shiomi, Shinji Yamagishi, Tokihiko Shinomiya, Shuichi Kozaki, Kohichi Fujimori
  • Patent number: 5781259
    Abstract: A liquid crystal display apparatus comprising a pair of transparent substrates which consists of a driving side substrate and an opposite side substrate; transparent pixels formed in matrix on said driving side substrate; a first orientation film formed on said pixels; a transparent electrode formed on said opposite side substrate; a shielding layer provided at least on the periphery of each of said transparent pixels and at either between said driving side substrate and said transparent pixels or between said transparent pixels and said orientation film; said pair of transparent substrates being located opposite to each other to form a cell in which a mixture comprising a liquid crystal, a photosetting polymer precursor and its polymerization initiator is put and irradiated with a light outside said cell thereby curing said photosetting polymer precursor selectively at a region free from said transparent pixels and enrich the resulting cured resin at said region.
    Type: Grant
    Filed: July 30, 1996
    Date of Patent: July 14, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tokihiko Shinomiya, Kohichi Fujimori, Tomoaki Kuratate
  • Patent number: 5769393
    Abstract: A display element for use in computer terminals, television displays and other information display devices capable of large capacity, full color display employing active elements, wherein an optical layer comprises liquid crystal and polymer dispersed in one another. The polymer comprises polymer grains directionally aligned in the optical layer by directional alignment of the liquid crystal, which is aligned by treatment provided relative to at least one of the substrates forming the display element. The polymer grains are developed from the polymerization of at least one polymer precursor containing at least one polymerizable portion and at least two aromatic rings with a coupling group provided between the aromatic rings. The polymer precursor contains, as at least one component, a polymer compound without an alkyl group spacer between the polymerizable portion and the aromatic rings.
    Type: Grant
    Filed: August 16, 1993
    Date of Patent: June 23, 1998
    Assignee: Seiko Epson Corporation
    Inventors: Hidekazu Kobayashi, Kiyohiro Samizu
  • Patent number: 5721597
    Abstract: A method and apparatus in which the liquid crystal material having cross-over frequency is used for displaying an image, the liquid crystal material is dispersed in the transparent polymer in a phase-separated state, a first voltage signal having a first frequency lower than the cross-over frequency is applied to the liquid crystal material to orient reversibly the liquid crystal material to a first direction to display temporary information, then a second voltage signal having a magnitude higher than the first voltage is selectively applied to orient permanently the liquid crystal material to the first direction to display permanent information and a third voltage signal having a second frequency higher than the cross-over frequency is selectively applied to orient the liquid crystal material perpendicularly to the first direction, to erase the permanent information.
    Type: Grant
    Filed: February 20, 1996
    Date of Patent: February 24, 1998
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Takeo Kakinuma, Kensuke Ito, Minoru Koshimizu
  • Patent number: 5709911
    Abstract: A polymerizable compound represented by Formula (I): ##STR1## where X is a hydrogen atom or a methyl group; Y and Z are independently a hydrogen atom or a fluorine atom; l is an integer of 0 to 14; m and n are independently an integer of 0 or 1; R is represented by Formula (II), (III), or (IV); and when m=1, l.gtoreq.
    Type: Grant
    Filed: February 21, 1997
    Date of Patent: January 20, 1998
    Assignees: Sharp Kabushiki Kaisha, Kanto Kagaku Kabushiki Kaisha
    Inventors: Noriaki Onishi, Nobuaki Yamada, Masahiko Yoshida, Hoyo Mizobe, Kenji Suzuki
  • Patent number: 5691795
    Abstract: A new liquid crystalline light modulating cell and material are characterized by liquid crystalline light modulating material of liquid crystal and polymer, the liquid crystal being a chiral nematic liquid crystal having positive dielectric anisotropy and including chiral material in an amount effective to form focal conic and twisted planar textures, the polymer being distributed in phase separated domains in the liquid crystal cell in an amount that stabilizes the focal conic and twisted planar textures in the absence of a field and permits the liquid crystal to change textures upon the application of a field. In one embodiment, the material is light scattering in a field-OFF condition and optically clear in a field-ON condition, while in another embodiment, the material is optically clear in a field-OFF condition and light scattering in a field-ON condition.
    Type: Grant
    Filed: April 20, 1995
    Date of Patent: November 25, 1997
    Assignee: Kent State University
    Inventors: J. William Doane, Deng-Ke Yang, Liang-Chy Chien
  • Patent number: 5680185
    Abstract: A polymer dispersed liquid crystal display apparatus has a liquid crystal/polymer medium formed between spatially disposed electrodes formed spatially disposed substrates. The medium includes a polymer phase and a liquid crystal phase having optical axes alignable together in a predetermined direction. A light absorption additive is included in the liquid crystal phase to provide light absorption when said optical axes are aligned in said predetermined direction so that in the presence or absence of an electric field applied between said electrodes, two different conditions are achieved comprising alignment and misalignment of the optical axes of the liquid crystal phase relative to the polymer phase so that in one condition, a light absorption state is created in the medium and in the other condition, a light scattering state is created in the medium.
    Type: Grant
    Filed: April 15, 1994
    Date of Patent: October 21, 1997
    Assignee: Seiko Epson Corporation
    Inventors: Hidekazu Kobayashi, Kiyohiro Samizu, Eiji Chino, Jin Jei Wu
  • Patent number: 5674576
    Abstract: In a liquid crystalline optical device, a light modulating layer composed of a liquid crystal and a high polymer resin is sandwiched between two substrates having electrode layers, at least one of the substrates being transparent. The polymer is a compound which is obtained by photopolymerization of a prepolymer containing a (meth)acryloyl compound having a stilbene skeleton, or a (meth)acryloyl compound including dioxane group or dioxolane group. The liquid crystalline optical device can be driven with a lower applied voltage and exhibits a reduced hysteresis.
    Type: Grant
    Filed: September 12, 1995
    Date of Patent: October 7, 1997
    Assignee: NEC Corporation
    Inventors: Tomohisa Gotoh, Taisaku Nakata, Hideya Murai, Etsuo Hasegawa
  • Patent number: 5661533
    Abstract: Surfactant-containing multistable cholesteric liquid crystal displays exhibit ultra fast response times with both video speed and gray scale capability.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: August 26, 1997
    Assignee: Advanced Display Systems, Inc.
    Inventors: Bao-Gang Wu, Hongxi Zhou, Yao-Dong Ma
  • Patent number: 5606442
    Abstract: A photocurable polymer precursor added to a liquid crystal material polymerizes to form a mixture that significantly lowers the threshold and saturation voltages of a standard twisted nematic cell. The performance characteristics of the resulting display device resembles those of a device with a very high pretilt, thereby providing an economical method of fabricating liquid crystal cells of a type that require a high pretilt alignment. The presence of the polymer substantially reduces adverse ion-related effects such as optical droop and charge retention in the liquid crystal display device.
    Type: Grant
    Filed: March 21, 1995
    Date of Patent: February 25, 1997
    Assignee: Tektronix, Inc.
    Inventors: Philip J. Bos, Jolly A. Rahman
  • Patent number: 5589959
    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.
    Type: Grant
    Filed: September 28, 1995
    Date of Patent: December 31, 1996
    Assignee: U.S. Philips Corporation
    Inventor: Rifat A. M. Hikmet