With Chiral Smectic Liquid Crystal (includes Ferroelectric Liquid Crystal) Patents (Class 349/133)
  • Patent number: 6411354
    Abstract: A broad class of lyotropic liquid crystals of a non-surfactant nature, the so-called lyotropic chromonic liquid crystals (LCLCs), are alignable in bulk. LCLCs can be aligned in bulk as a uniform liquid crystalline monodomain within a closed cell. The method for bulk alignment of LCLCs is based on a unidirectional treatment of the aligning substrate such as a polymer layer. The feature of controlling the alignment of LCLCs enables one to create practical devices from them. For example, bulk alignment of LCLCs allows one to use them in detection and amplification of ligands.
    Type: Grant
    Filed: May 11, 2001
    Date of Patent: June 25, 2002
    Assignee: Kent State University
    Inventors: Oleg D. Lavrentovich, Tomohiro Ishikawa
  • Publication number: 20020057409
    Abstract: A ferroelectric liquid crystal display includes a pair of first and second substrates placed substantially in parallel to each other to form a space between the first and second substrates so that a ferroelectric liquid crystal is provided in the space between the first and second substrates, wherein the ferroelectric liquid crystal is isolated into co-existent separate orientation regions that have crystal orientations which differ by 90 degrees from each other in initial orientation direction of an optical axis of ferroelectric liquid crystal molecules when no electric field is applied to the ferroelectric liquid crystal immediately after the ferroelectric liquid crystal has been injected into the space between the first and second substrates.
    Type: Application
    Filed: December 17, 2001
    Publication date: May 16, 2002
    Applicant: NEC Corporation
    Inventor: Toshiya Ishii
  • Publication number: 20020041353
    Abstract: A chiral smectic liquid crystal device is constituted by a chiral smectic liquid crystal; a pair of substrates each provided with an electrode for applying a voltage to the liquid crystal and an alignment control layer formed by oblique vapor deposition, the pair of substrates being oppositely disposed to sandwich the liquid crystal so as to form a plurality of pixels each provided with an active element connected to an associated electrode on at least one of the substrates; and a polarizer provided to at least one of the substrates. The liquid crystal has a phase transition series on temperature decrease of isotropic liquid phase (Iso), cholesteric phase (Ch) and chiral smectic C phase (Smc*) or of Iso and SmC*.
    Type: Application
    Filed: May 22, 2001
    Publication date: April 11, 2002
    Inventors: Koji Noguchi, Hirohide Munakata, Mutsuo Mitsui, Yasufumi Asao, Ryuichiro Isobe
  • Publication number: 20020012092
    Abstract: A liquid crystal display device and a method for fabricating a liquid crystal display device wherein two domains are provided within each pixel cell so as to prevent flicker and to widen a viewing angle. In the liquid crystal display device, a common electrode is formed on a first substrate in such a manner to be divided into at least two electrodes. An alignment film is coated on the first substrate provided with the common electrode and a second substrate. A ferroelectric liquid crystal layer is injected between the first substrate and the second substrate to form at least two domains having a liquid crystal alignment state opposed to each other on a basis of a dividing line of the common electrode.
    Type: Application
    Filed: June 29, 2001
    Publication date: January 31, 2002
    Applicant: LG.Philips LCD Co., Ltd.
    Inventors: Hyeon Ho Son, Su Seok Choi, Jong Jin Park
  • Patent number: 6335777
    Abstract: A liquid crystal device, comprising: a pair of substrates each provided with an electrode including one substrate having thereon a color filter and a coating layer, and a liquid crystal layer comprising a chiral smectic liquid crystal disposed together with spacer beads between the pair of substrates, wherein the liquid crystal layer has a thickness smaller than a diameter of the spacer beads and a maximum thickness of the coating layer, the coating layer having a pencil hardness of at most 7 H. The above layer structure between the substrates is effective in improving resistance to external shock and providing a uniform cell gap.
    Type: Grant
    Filed: July 11, 2000
    Date of Patent: January 1, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yuko Yokoyama, Yuichi Masaki, Kazuya Ishiwata, Tetsuro Saito, Yoshinori Shimamura, Tadashi Mihara, Kazunori Katakura, Sunao Mori, Chikako Tsujita
  • Patent number: 6335775
    Abstract: In a liquid crystal device in which a pair of substrates each having an electrode and a liquid crystal orientation control layer are disposed opposite to each other leaving a predetermined gap therebetween and liquid crystal is disposed in the gap, a plurality of grooves are formed on each of the inner surface contacting the liquid crystal, the section of the inner surfaces in a direction along the grooves has such a shape that repetitive asymmetrical projections are formed and the radius of curvature of the grooves in a direction intersecting the grooves is set to 0.1 &mgr;m or more.
    Type: Grant
    Filed: September 26, 1996
    Date of Patent: January 1, 2002
    Assignee: Sony Corporation
    Inventors: Takashi Iwamura, Nobuhiro Kihara, Takeshi Yamasaki, Katsuya Shirai, Keiichi Nito, Masanobu Yamamoto, Akio Yasuda
  • Publication number: 20010055084
    Abstract: A liquid crystal device, comprising: a pair of substrates each provided with an electrode including one substrate having thereon a color filter and a coating layer, and a liquid crystal layer comprising a chiral smectic liquid crystal disposed together with spacer beads between the pair of substrates, wherein the liquid crystal layer has a thickness smaller than a diameter of the spacer beads and a maximum thickness of the coating layer, the coating layer having a pencil hardness of at most 7H. The above layer structure between the substrates is effective in improving resistance to external shock and providing a uniform cell gap.
    Type: Application
    Filed: July 2, 2001
    Publication date: December 27, 2001
    Inventors: Yuko Yokoyama, Yuichi Masaki, Kazuya Ishiwata, Tetsuro Saito, Yoshinori Shimamura, Tadashi Mihara, Kazunori Katakura, Sunao Mori, Chikako Tsujita
  • Patent number: 6326940
    Abstract: A ferroelectric liquid crystal display includes a cell comprising a layer of ferroelectric liquid crystal material contained between two transparent glass substrates having alignment layers for determining the surface alignment of the molecules in the liquid crystal material. The display further incorporates switching circuitry for switching the molecules in the liquid crystal material between a first state and a second state by means of a switching signal having a duration &tgr; and a voltage V. The liquid crystal material and the alignment layers are such that the cell exhibits a &tgr;-V response in the form of a curve having two minima separated by an intermediate maximum. Such a &tgr;-V response, which may be termed a double turnaround response, allows a high degree of discrimination between the switched and non-switched states beyond the turnaround point and offers potential addressing advantages.
    Type: Grant
    Filed: June 28, 1999
    Date of Patent: December 4, 2001
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Karl Philip Lymer, John Clifford Jones
  • Patent number: 6320635
    Abstract: Disclosed is a liquid crystal element capable of reducing the threshold voltage value, temperature-dependence on light transmittance, and hysteresis phenomenon. The liquid crystal element basically includes a pair of substrates each having a liquid crystal orientation film, wherein the surface sides, on which the liquid crystal orientation films are formed, of the substrates are opposed to each other with a specific gap put therebetween and a liquid crystal is arranged in the gap. The liquid crystal orientation film includes: a SiOx obliquely vapor-deposited film (x: positive number less than 2); and a polyvinyl alcohol based thin film stacked on the obliquely vapor-deposited film to a thickness of 0.1 &mgr;m or less (the concentration of the polyvinyl alcohol based water solution is 1 wt % or less) allowed to keep irregularities of oblique pillars of the obliquely vapor-deposited film.
    Type: Grant
    Filed: February 5, 1999
    Date of Patent: November 20, 2001
    Assignee: Sony Corporation
    Inventor: Eriko Matsui
  • Patent number: 6320639
    Abstract: A matrix-type liquid crystal device is formed so as to have a matrix of pixels defined by and isolated from each other by an outside-pixel region. The liquid crystal in the outside-pixel region in placed in an alignment state, typically a homeotropic state or one close thereto, which is different from an alignment state, typically a homogeneous uniform alignment state, at the pixel region. As a result, the liquid crystal device is provided with improved display qualities due to suppression of irregularities at the outside-pixel region and/or a local pressure distribution.
    Type: Grant
    Filed: March 6, 1997
    Date of Patent: November 20, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Sunao Mori, Takashi Enomoto, Toshifumi Yoshioka, Yasuyuki Watanabe, Kazuhiro Aoyama, Junji Kawasaki, Kouki Nukanobu
  • Patent number: 6307610
    Abstract: A liquid crystal device comprises a liquid crystal cell including a layer of ferroelectric smectic liquid crystal material contained between two walls bearing electrodes and surface treated to give both an alignment and a surface tilt to liquid crystal molecules. The material adopts a C2 rather than a C1 arrangement by arranging the surface pretilt &xgr; and the ratio of azimuthal to zenithal anchoring energies &bgr;/&agr; to give a positive energy difference &Dgr;Ws for the liquid crystal director at the surface in the C1 and C2 states. Additionally the provision of a C2 state may be enhanced by allowing the cell to cool from the isotropic phase to a temperature just below a smectic A to chiral smectic phase, then applying 50 Hz ac voltage in the range typically 0.1 to 5 volts rms. across the liquid crystal layer for about 90 seconds, then allowing the cell to cool to ambient temperature.
    Type: Grant
    Filed: August 4, 1998
    Date of Patent: October 23, 2001
    Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventor: John C Jones
  • Patent number: 6304310
    Abstract: An liquid crystal apparatus, includes: (a) a liquid crystal device including: a pair of substrates each provided with a uniaxial alignment axis, and a chiral smectic liquid crystal having a negative dielectric anisotropy disposed between the pair of substrates and capable of forming a higher-temperature bistable alignment state and a lower-temperature bistable alignment state in its chiral smectic C phase, the chiral smectic liquid crystal being further placed in the lower-temperature bistable alignment state formed by cooling from the higher-temperature bistable alignment state; and (b) voltage application means including: an AC voltage application means for applying to the chiral smectic liquid crystal an AC voltage insufficient to cause a switching from one to the other or from the other to one of the bistable alignment state, and a switching voltage application means for applying to the chiral smectic liquid crystal a voltage of one polarity sufficient to cause a switching from one to the other of the bis
    Type: Grant
    Filed: November 12, 1992
    Date of Patent: October 16, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hideyuki Kawagishi, Yutaka Inaba
  • Patent number: 6297865
    Abstract: A liquid crystal element improved to reduce hysteresis and after-image by relaxing electronic polarization at an interface between liquid crystal and an orientation film, and hence to enhance an image quality and realize smooth display of a dynamic image irrespective of a material of liquid crystal. The liquid crystal element includes a plurality of base bodies each having a liquid crystal orientation film, the base bodies being opposed to each other on the orientation film side with a specific gap put therebetween; and liquid crystal disposed in the gap; wherein each of the orientation films has a property capable of relaxing polarization at an interface with the liquid crystal.
    Type: Grant
    Filed: March 10, 1998
    Date of Patent: October 2, 2001
    Assignee: Sony Corporation
    Inventors: Eriko Matsui, Nobue Kataoka, Takashi Iwamura, Hidehiko Takanashi, Akio Yasuda
  • Patent number: 6295112
    Abstract: A method of aligning a liquid crystal includes a step of fixing on a hot plate and heating a liquid crystal cell in which a liquid crystal composed of a ferroelectric liquid crystal material sealed between electrode substrates respectively having alignment films having applied thereto a uniaxial alignment by rubbing. According to the described method, a pressure is applied to the liquid crystal cell by a roller, and a portion subjected to an application of pressure is moved by moving the roller. Further, the liquid crystal is heated within a temperature range between a phase transition temperature of SmA phase SmC* phase and a temperature 10° C. below the phase transition temperature, and the portion subjected to an application of pressure is moved in the same direction as the rubbing direction, thereby achieving the C2 orientation at higher yield.
    Type: Grant
    Filed: April 23, 1997
    Date of Patent: September 25, 2001
    Assignees: Sharp Kabushiki Kaisha, The Secretary of State for Defense in her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventors: Masaaki Kabe, Takashi Kaneko, Mitsuhiro Koden, Mitsuhiro Shigeta, Nobuyuki Itoh
  • Patent number: 6266115
    Abstract: A liquid crystal cell and liquid crystal display device include: two electrode substrates facing each other through a plurality of spacers; each electrode substrate being formed by superimposing a glass substrate, a transparent electrode and an alignment film; and an antiferroelectric liquid crystal being injected between alignment films; wherein, an alignment treatment is performed to each alignment film so that an angle of layer rotation of the antiferroelectric liquid crystal is defined within a predetermined allowable range.
    Type: Grant
    Filed: September 9, 1996
    Date of Patent: July 24, 2001
    Assignees: Nippondenso Co., Ltd., Nippon Soken, Inc.
    Inventors: Takayuki Fujikawa, Akira Takeuchi, Norio Yamamoto, Yuichiro Yamada, Masaaki Ozaki
  • Patent number: 6233027
    Abstract: A liquid crystal device includes a pair of transparent substrates disposed with a prescribed gap therebetween and each having a transparent electrode thereon, a photoelectric conversion semiconductor layer not subjected to rubbing formed on one of the pair of transparent substrates, and alignment film subjected to rubbing formed on the other of the pair of transparent substrates, an a liquid crystal disposed between the photoelectric conversion semiconductor layer and the alignment film. As the photoelectric conversion semiconductor is freed from an aligning performance, the material thereof is freed from the constraint and can be selected so as to optimize the photoelectric conversion performance.
    Type: Grant
    Filed: January 7, 1998
    Date of Patent: May 15, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akira Unno, Mineto Yagyu, Yuichi Hashimoto
  • Patent number: 6195147
    Abstract: A liquid crystal device is constituted by a pair of substrates and a liquid crystal disposed in a uniform alignment state between the substrates. At least one of the substrate has a surface contacting the liquid crystal and including a first region having a larger uniaxial alignment control force and a second region having a smaller or substantially no uniaxial alignment control force, respectively acting on the liquid crystal. In the device, phase transition from liquid phase to mesomorphic phase on temperature decrease, of the liquid crystal has been initiated from a portion contacting the first region and enlarged toward the second region to place the liquid crystal in a uniform alignment state, thus ensuring an increased effective voltage applied to the liquid crystal while retaining a good alignment characteristic to improve drive and display characteristics.
    Type: Grant
    Filed: July 31, 1998
    Date of Patent: February 27, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasufumi Asao, Yasuyuki Watanabe, Masahiro Terada, Shosei Mori, Seishi Miura, Takashi Moriyama
  • Patent number: 6172727
    Abstract: The present invention relates to a structure of a liquid crystal (LC) cell using an antiferroelectric liquid crystal. The LC cell includes: an electrode substrate with color filters; an opposite electrode substrate; a first alignment film provided on the electrode substrate with color filters; a second alignment film provided on the opposite electrode substrate; an antiferroelectric liquid crystal provided between the first and second alignment films; and the electrode substrate with color filters and the opposite electrode substrate being superimposed so as to face each other through the first alignment film, the antiferroelectric liquid crystal, and the second alignment film. In the present invention, an alignment process of the first alignment film is performed based on a rubbing density larger than the rubbing density of the second alignment film so that an angle of layer rotation of the antiferroelectric liquid crystal is defined within a predetermined allowable angle range.
    Type: Grant
    Filed: March 31, 1998
    Date of Patent: January 9, 2001
    Assignee: Denso Corporation
    Inventors: Masaaki Ozaki, Tetsuya Sano, Takayuki Fujikawa, Norio Yamamoto
  • Patent number: 6169531
    Abstract: In display devices based on ferroelectric liquid-crystal material with deformable helix, ferroelectric liquid-crystal material with a twisted smectic structure, monostable ferroelectric liquid-crystal material, electroclinic smectic A liquid-crystal material and anti-ferroelectric liquid-crystal material, the memory effect, particularly in the case of video applications, is eliminated by presenting reset pulses in successive row selection times during a part of these times (for example in the case of matrix displays based on TFTs), so that the polarization within a cell is always reduced to zero and, after selection for the purpose of writing data, switches to the proper value.
    Type: Grant
    Filed: February 7, 1997
    Date of Patent: January 2, 2001
    Assignee: U.S. Philips Corporation
    Inventor: Antonius G. H. Verhulst
  • Patent number: 6144435
    Abstract: A liquid crystal device, comprising: a pair of substrates each provided with an electrode including one substrate having thereon a color filter and a coating layer, and a liquid crystal layer comprising a chiral smectic liquid crystal disposed together with spacer beads between the pair of substrates, wherein the liquid crystal layer has a thickness smaller than a diameter of the spacer beads and a maximum thickness of the coating layer, the coating layer having a pencil hardness of at most 7 H. The above layer structure between the substrates is effective in improving resistance to external shock and providing a uniform cell gap.
    Type: Grant
    Filed: April 26, 1996
    Date of Patent: November 7, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yuko Yokoyama, Yuichi Masaki, Kazuya Ishiwata, Tetsuro Saito, Yoshinori Shimamura, Tadashi Mihara, Kazunori Katakura, Sunao Mori, Chikako Tsujita
  • Patent number: 6139927
    Abstract: A liquid crystal device is constituted by a pair of substrates each provided with an electrode, and a chiral smectic liquid crystal composition disposed between the substrates. At least one of the substrates is provided with an alignment control film of a polyimide represented by the following formula (I): ##STR1## in which A denotes a planar tetravalent organic residue group; B denotes a divalent group represented by --CR.sub.1 (R.sub.2)-- where R.sub.1 and R.sub.2 independently denote H or alkyl group; a, b and c are independently 0 or 1; x and y are independently an integer of at least 0 and x+y=at least 1; and n is an integer of at least 2.
    Type: Grant
    Filed: September 17, 1998
    Date of Patent: October 31, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hideaki Takao, Masahiro Terada, Yasushi Shimizu, Katsumi Arai, Shosei Mori, Yasufumi Asao, Takashi Moriyama, Takeshi Togano
  • Patent number: 6128064
    Abstract: A liquid crystal device is constituted by a chiral smectic liquid crystal and a pair of substrates sandwiching the chiral smectic liquid crystal therebetween and each having thereon an electrode for applying a voltage to the liquid crystal. At least one of the substrates being provided with an alignment control film comprising a specific aromatic polyimide which has been subjected to a uniaxial aligning treatment. The chiral smectic liquid crystal assumes bistability in a chiral smectic temperature range when incorporated in a test cell which is not provided with an alignment control film and has been subjected to shearing treatment. In the liquid crystal device including the polyimide alignment control film, the chiral smectic liquid crystal at least has a voltage-transmittance characteristic such that an effective tilt angle and a transmittance continuously change depending on an electric field applied thereto.
    Type: Grant
    Filed: July 14, 1999
    Date of Patent: October 3, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takashi Moriyama, Takao Takiguchi, Yukio Hanyu, Koichi Sato, Masahiro Terada, Shinichi Nakamura, Yasufumi Asao, Koji Noguchi, Yasushi Shimizu
  • Patent number: 6122031
    Abstract: A liquid crystal device is constituted by a pair of oppositely disposed substrates each provided with an alignment control layer, and a liquid crystal layer comprising a liquid crystal material and disposed between the substrates with a spacer member. In the device, the spacer member has an electrical conductivity larger than that of the liquid crystal material. Further, the liquid crystal layer containing the spacer member has a first resistance in a direction of a normal to the substrates in a prescribed temperature range substantially lower than a second resistance of a corresponding liquid crystal layer, in the identical direction, consisting only of the liquid crystal material and having the identical plane area and thickness. The liquid crystal device is effective in providing an improved drive margin in a wide temperature range while suppressing a DC offset voltage component applied to the liquid crystal layer.
    Type: Grant
    Filed: February 10, 1997
    Date of Patent: September 19, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masahiro Terada, Yutaka Inaba, Kazunori Katakura, Yasufumi Asao
  • Patent number: 6097454
    Abstract: In an active matrix liquid-crystal display device, a metal common electrode 22 that also serves as a black matrix is disposed to cover the peripheral portion of a pixel electrode 24 which is formed of a transparent electrically conductive film. The common electrode 22 functions as the black matrix that covers the peripheral portion of a pixel and is held to a given potential, so that a region where the pixel electrode 24 and the common electrode 22 are overlapped with each other functions as an auxiliary capacitor 25. The auxiliary capacitor is structured through an insulation layer 23. The common electrode 22 is formed on the insulation layer 21 having a flatten surface to make the auxiliary capacitor 25 larger. With this structure, even though the insulation layer 23 is thinned to about 1 .mu.m, a pin hole, leakage, etc., between the common electrode and the pixel electrode can be prevented, to thereby obtain a larger auxiliary capacitor.
    Type: Grant
    Filed: June 29, 1999
    Date of Patent: August 1, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Naoaki Yamaguchi, Yasuhiko Takemura
  • Patent number: 6094251
    Abstract: A ferroelectric liquid crystal display (FLCD), which comprises a cell including a layer of chiral smetic ferroelectric liquid crystal material contained between two substrates and at least one alignment layer for determining the surface alignment of the molecules in the liquid crystal material, is manufactured as follows. After selection of a suitable material for the alignment layer, the cell is filled by introducing liquid crystal material between the substrates to which the alignment layer is applied. After filling of the cell, a heat treatment is applied to the cell by raising the cell to an elevated temperature and maintaining the cell at that temperature for a predetermined period of time.
    Type: Grant
    Filed: November 18, 1999
    Date of Patent: July 25, 2000
    Assignees: Sharp Kabushiki Kaisha, The Secretary of State for Defence in Her Brittanic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventors: John Clifford Jones, Simon David Haslam, Robert William Bannister
  • Patent number: 6091388
    Abstract: A driving method for an optical modulation device is applicable to driving of an optical modulation device, e.g. a liquid crystal device having a matrix electrode arrangement comprising a group of scanning electrodes, a group of signal electrodes oppositely spaced from the group of scanning electrodes, and an optical modulation material (e.g. a liquid crystal) showing bistability with respect to an electric filed applied thereto disposed between the groups of scanning electrodes and signal electrodes.
    Type: Grant
    Filed: May 27, 1997
    Date of Patent: July 18, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Junichiro Kanbe, Kazuharu Katagiri, Syuzo Kaneko
  • Patent number: 6091472
    Abstract: For a liquid crystal display apparatus, an orientating film of an electrode substrate including more signal electrodes than scanning electrodes in a predetermined range receives a uniaxial orientation treatment parallelly or almost parallelly to a lengthwise direction of the signal electrodes. Besides, an orientating film of an electrode substrate including the scanning electrodes receives a uniaxial orientation treatment perpendicularly or almost perpendicularly to a lengthwise direction of the scanning electrodes. The electrode substrates are combined so that the directions of the uniaxial orientation treatment of the orientation films become parallel to each other. This enables growth of a smectic layer to be less frequently hindered by differences in level caused by the electrodes. Thus a uniform C2U orientation can be obtained easily. Consequently, the liquid crystal display apparatus realizes a uniform orientational state with no defects and uniform and high-contrast display properties.
    Type: Grant
    Filed: November 20, 1996
    Date of Patent: July 18, 2000
    Assignees: Sharp Kabushiki Kaisha, The Secretary of State for Defence in Her Brittanic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventors: Nobuyuki Itoh, Masami Kido
  • Patent number: 6046788
    Abstract: A liquid crystal material is sealed between substrates. The liquid crystal material exhibits an antiferroelectric phase while the liquid crystal is in a bulk state. In the liquid crystal layer sealed between the substrates, due to aligning forces of alignment films, liquid crystal molecules are aligned in a state wherein there is no correlation in molecular order between adjoining smectic layers, and the director of the liquid crystal layer is substantially coincident with the direction of a normal line of the smectic layers. The director varies continuously in accordance with the polarity and magnitude of a voltage applied between electrodes formed on the substrates. Arranging polarization plates so that the substrates are sandwiched therebetween enables a gradation to be displayed.
    Type: Grant
    Filed: May 6, 1998
    Date of Patent: April 4, 2000
    Assignee: Casio Computer Co., Ltd.
    Inventors: Tomio Tanaka, Tetsushi Yoshida, Manabu Takei, Jun Ogura
  • Patent number: 6040884
    Abstract: A liquid crystal device comprises a pair of substrates and a liquid crystal provided between the paired substrates wherein domains whose threshold voltages are different from one another are finely distributed throughout the liquid crystal. In particular, the respective substrates each has a transparent electrode and an alignment film formed thereon in this order and the substrates are assembled to establish a given space therebetween, and a ferroelectric liquid crystal being injected into the given space wherein domains are finely distributed as set out above, thereby providing a a liquid crystal display device. The fine distribution is such that when a transmittance through inverted domains is 25%, the number of domains (microdomains) having a size of larger than 2 .mu.m.phi. in a field of 1 mm.sup.2 is not smaller than 300, preferably not smaller than 600, and the width of the threshold voltage within the domains is not smaller than 2 volts within a transmittance range of from 10 to 90%.
    Type: Grant
    Filed: July 25, 1997
    Date of Patent: March 21, 2000
    Assignee: Sony Corporation
    Inventors: Akio Yasuda, Keiichi Nito, Eriko Matsui, Hidehiko Takanashi, Yang Ying Bao
  • Patent number: 6001276
    Abstract: A liquid crystal device is constituted by a pair of transparent substrates each having thereon a transparent electrode, and a chiral smectic liquid crystal composition lacking cholesteric phase disposed between the substrates so as to assume at least two optically stable states. At least one of the substrates is provided with an alignment film which comprises a polyimide represented by a recurring unit of formula (I) shown below and has been subjected to a uniaxial aligning treatment. ##STR1## wherein A denotes a tetravalent aliphatic hydrocarbon group free from a planar structure or a tetravalent alicyclic hydrocarbon group, and n is an integer of at least 1. The chiral smectic liquid crystal composition may preferably contain at least one species of fluorine-containing mesomorphic compound comprising a fluorocarbon terminal portion and a hydrocarbon terminal portion connected with a central core and having a smectic phase or a latent smectic phase.
    Type: Grant
    Filed: July 18, 1997
    Date of Patent: December 14, 1999
    Assignee: Canon Kabishiki Kaisha
    Inventors: Masanobu Asaoka, Hideaki Takao, Koichi Sato, Masahiro Terada, Shinichi Nakamura, Ikuo Nakazawa
  • Patent number: 5990856
    Abstract: In a ferroelectric liquid crystal element, in order to excite a reverse electric field within the element in response to a waveform of a non-rewriting voltage, properties of the ferroelectric liquid crystal material, an element structure, driving waveforms, or other factors are adjusted so that molecules of the ferroelectric liquid crystal are allowed to switch between bistable states in response to a waveform of a rewriting voltage, while the ferroelectric liquid crystal exerts an anti-memory phenomenon in response to a waveform of a non-rewriting voltage.
    Type: Grant
    Filed: April 17, 1997
    Date of Patent: November 23, 1999
    Assignees: Sharp Kabushiki Kaisha, The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventors: Hitoshi Takeda, Takashi Kaneko, Masami Kido, Mitsuhiro Koden
  • Patent number: 5973762
    Abstract: A ferroelectric liquid crystal cell with a monochevron structure includes a pair of opposed substrates each having an alignment layer. The alignment layer includes a conventional polymer and a ferroelectric copolymer. A ferroelectric liquid crystal material is disposed between the pair of opposed substrates and interacts with the alignment layers which force the ferroelectric liquid crystal into a monochevron structure because of the interaction between the ferroelectric liquid crystal material polarization and polarization of the alignment layers.
    Type: Grant
    Filed: June 4, 1998
    Date of Patent: October 26, 1999
    Assignee: Kent State University
    Inventor: Valeri Vorfloussev
  • Patent number: 5973761
    Abstract: A liquid crystal device is formed by a pair of substrates, and a liquid crystal disposed between the substrates. At least one substrate has thereon a laminar structure including an electrode, an electrical property control layer and an alignment control layer contacting the liquid crystal disposed in this order on the substrate. The alignment control layer has a thickness of at most 100 .ANG., has been subjected to a uniaxial aligning treatment and has a volume resistivity larger than that of the electrical property control layer. The liquid crystal device thus constituted may exhibit a reduced influence of reverse electric field and a suppressed switching asymmetry over a wide temperature range.
    Type: Grant
    Filed: January 29, 1998
    Date of Patent: October 26, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Ihachiro Gofuku, Shinjiro Okada, Yasuto Kodera, Masahiro Terada, Fumikazu Kobayashi, Nobuhiro Ito
  • Patent number: 5933128
    Abstract: A liquid crystal apparatus includes (a) a liquid crystal panel including: a pair of substrates having thereon a group of scanning electrodes and a group of data electrodes, respectively, and provided with mutually different alignment characteristics, and a chiral smectic liquid crystal disposed between the substrates so as to form a pixel at each intersection of the scanning electrodes and the data electrodes, and (b) drive means for: sequentially applying a scanning selection signal to the scanning electrodes to select at least one scanning electrode, and applying a data signal having at least three peak values to the data electrodes in synchronism with the scanning selection signal. A DC bias voltage may be applied between the scanning electrodes and the data electrodes, and the polarity of the DC voltage may be switched for each prescribed period. The above system is suitable for obviating or suppressing the "sticking" phenomenon of a chiral smectic liquid crystal.
    Type: Grant
    Filed: May 17, 1996
    Date of Patent: August 3, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaki Kuribayashi, Osamu Ikeda, Kazunori Katakura, Hironao Kimura, Hidetoshi Tsuzuki
  • Patent number: 5907645
    Abstract: The modulator is formed by a smectic chiral ferroelectric C* liquid crystal cell (CL), crossed by the light signal which is transmitted by the said fibre. The cell (CL) is provided with transparent walls and transparent command electrodes (5 to 7). The liquid crystal (CL), used in half-wave mode, is of the SSFLC (surface stabilized ferroelectric liquid crystal) type, having a wide tile angle .theta., which is as close as possible to 45.degree., in such a way that the said modulator is insensitive to polarisation. The modulator may be connected to two parallel fibres (A2, A3; B2, B3), pertaining to the intermediary part of a Mach-Zehnder coupler between the two 3 dB couplers, and when it is provided in order to modulate the light signal transmitted by either one of the two fibres.
    Type: Grant
    Filed: December 23, 1996
    Date of Patent: May 25, 1999
    Assignee: France Telecom
    Inventors: Laurent Dupont, Jean-Louis de Bougrenet de la Tocnaye, Michel Monerie
  • Patent number: 5880802
    Abstract: An active matrix liquid crystal display improves its contrast by suppressing irregularity of an alignment film caused by video lines thereby reducing reverse regions on a display electrode. The active matrix liquid crystal display has first and second opposite substrates, a video line, an active element and a display electrode which are directly or indirectly formed on the first substrate, and an alignment film which is formed on or above the video line, the active element and the display electrode. The alignment film is so formed that its surface is at an angle of inclination of not more than 10.5.degree. with respect to the display electrode surface between the video line and the display electrode.
    Type: Grant
    Filed: March 27, 1996
    Date of Patent: March 9, 1999
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Hiroaki Kouno, Susumo Oima, Yasuo Segawa, Norio Tabuchi, Shouzou Ohura, Hiroki Hamada, Kiyoshi Yoneda
  • Patent number: 5880803
    Abstract: A liquid crystal display element is provided with a first insulating substrate having spacers and an alignment layer that covers the entire surfaces of the spacers, and a second insulating substrate having at least an alignment layer. The liquid crystal display element is arranged so that the first and second insulating substrates are bonded to each other by allowing the alignment layer on the spacers of the first insulating substrate and the alignment layer on the second insulating substrate to soften and adhere to each other by applying a pressure under heat, and liquid crystal is injected into the gap in between.
    Type: Grant
    Filed: November 5, 1996
    Date of Patent: March 9, 1999
    Assignees: Sharp Kabushiki Kaisha, The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventors: Kazuhiko Tamai, Mitsuhiro Koden
  • Patent number: 5860212
    Abstract: A method of coating a conductive substance on a transparent electrode disposed on a substrate comprises disposing a resin containing the conductive substance over the surface of the substrate, and rubbing and pressing the resin over the surface of the substrate with a pressing shaft to coat a layer of the resin on the transparent electrode. A method of mounting a semiconductor device or the film substrate on the substrate having the transparent electrode coated with the resin layer containing the conductive substance comprises connecting a terminal portion of the semiconductor device or film substrate to the transparent electrode through the resin layer.
    Type: Grant
    Filed: March 22, 1995
    Date of Patent: January 19, 1999
    Assignee: Seiko Instruments Inc.
    Inventor: Tsutomu Matsuhira
  • Patent number: 5856432
    Abstract: A polyimide alignment film based on pyromellitic dianhydride and a bis(4-aminophenoxy) aromatic compound, such as 1,3-bis(4-aminophenoxy)benzene or 1,4-bis(4-aminophenoxy)benzene, providing low tilt angles of from 1 to 2 degrees when used in liquid crystal displays.
    Type: Grant
    Filed: November 20, 1997
    Date of Patent: January 5, 1999
    Assignees: E. I. duPont de Nemours and Company, Merck Patent GmbH
    Inventors: Brian Carl Auman, Edgar Bohm
  • Patent number: 5825447
    Abstract: A chiral smectic liquid crystal device with good planar homogeneity in a layer normal direction can be constituted by disposing a chiral smectic liquid crystal having no cholesteric phase between a pair of substrates having mutually different characters, particularly in terms of Iso-SmA phase transition temperature. The liquid crystal may preferably have a layer spacing-changing characteristic such that it provides a layer spacing d.sub.A at a first transition point where the layer spacing of the liquid crystal begins to decrease on temperature decrease in the vicinity of a transition temperature from SmA phase to SmC* phase and a layer spacing d.sub.min at a second transition point where the layer spacing of the liquid crystal begins to increase on further temperature decrease from the first transition point, satisfying 0.96.ltoreq.d.sub.min /d.sub.A.
    Type: Grant
    Filed: June 19, 1996
    Date of Patent: October 20, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yukio Hanyu, Katsutoshi Nakamura, Nobuhiro Ito
  • Patent number: 5818557
    Abstract: A liquid crystal device comprising:a pair of substrates having an electrode arrangement thereon;an orientation control means provided on at least one of said substrates; anda ferroelectric or antiferroelectric liquid crystal layer interposed between said substrates, said liquid crystal layer being uniaxially oriented by virtue of said orientation control means,wherein means for suppressing an orientation control effect of said orientation control means with respect to said liquid crystal layer is provided between said liquid crystal layer and said orientation control means.
    Type: Grant
    Filed: January 26, 1996
    Date of Patent: October 6, 1998
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Toshimitsu Konuma, Takeshi Nishi, Michio Shimizu, Harumi Mori, Kouji Moriya, Satoshi Murakami
  • Patent number: 5815230
    Abstract: A liquid crystal device is constituted by a pair of oppositely disposed substrates having opposing inner surfaces and opposing electrodes thereon, and a chiral smectic liquid crystal assuming two stable states disposed between the opposing electrodes. The opposing inner surfaces of the pair of substrates have been subjected to an aligning treatment such that the liquid crystal placed in one of the two stable states moves under application of an electric field in a direction identical to one in which the liquid crystal placed in the other of the two stable states moves under the application of the electric field. The liquid crystal device has an effective optical modulation region and a peripheral region outside the effective optical modulation region, wherein the effective optical modulation region and the photosensitive member have been subjected to different aligning treatments.
    Type: Grant
    Filed: January 27, 1995
    Date of Patent: September 29, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Seishi Miura, Hideaki Takao, Masanobu Asaoka, Bunryo Sato, Tadashi Mihara, Yasuto Kodera, Makoto Kojima, Masamichi Saito, Sunao Mori, Kazuhiro Aoyama
  • Patent number: 5808716
    Abstract: A liquid crystal display includes glass cell walls on which are formed alignment layers. The cell is filled with liquid crystal material, such as FLC material. Chemical bonds are formed between the alignment layers and the adjacent liquid crystal layers so that the liquid crystal layers are bonded to the alignment layers in order to increase resistance to mechanical damage.
    Type: Grant
    Filed: October 3, 1995
    Date of Patent: September 15, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Paul Antony Gass, Michael John Towler, Tomoaki Kuratate, Martin David Tillin, Harald Reinhart Bock, Harry Garth Walton
  • Patent number: 5800736
    Abstract: A liquid crystal composition is realized, which composition simultaneously exhibits a negatively large .DELTA..di-elect cons. value suitable to .tau.-Vmin, and SA phase within a sufficient temperature range for realizing a good alignment.A smectic liquid crystal composition containing component (AI), component (B) and/or component (C), expressed by the following formulas: ##STR1## wherein R.sup.1 represents an alkyl group of 1 to 9 carbon atoms, R.sup.2 represents an alkyl group of 1 to 9 carbon atoms, R.sup.3 represents an alkyl group of 1 to 18 carbon atoms, R.sup.4 represents an alkyl group of 1 to 18 carbon atoms, X represents H or F, R.sup.5 represents an alkyl group of 6 to 15 carbon atoms and R.sup.6 represents an alkyl group of 6 to 15 carbon atoms.Ferroelectric liquid crystal material having a negative dielectric anisotropy is applicable to display element utilizing AC-stabilizing effect and .tau.-Vmin.
    Type: Grant
    Filed: January 5, 1998
    Date of Patent: September 1, 1998
    Assignees: Chisso Corporation, Sharp Kabushiki Kaisha
    Inventors: Eiji Okabe, Mayumi Tanabe, Shinichi Saito, Akira Sakaigawa, Hitoshi Takeda, Masami Kido, Takashi Kaneko, Mitshuhiro Koden, Teiyu Sako
  • Patent number: 5798056
    Abstract: An aligning method of a chiral smectic liquid crystal showing a phase transition series of isotropic phase, smectic phase, and chiral smectic phase in this order on temperature decrease is provided. In the aligning method, the chiral smectic liquid crystal is disposed between a pair of electrode plates at least one of which is provided with an alignment control layer, preferably one having been subjected to a uniaxial aligning treatment (e.g., rubbing), and then is subjected to a treatment including a cycle of heating and cooling in temperatures ranging between a lower limit temperature showing chiral smectic phase and an upper limit temperature showing isotropic phase and smectic phase in mixture. The upper limit temperature may preferably be below an isotropic-smectic phase transition temperature by at most 3.degree. C., particularly at most 1.degree. C.
    Type: Grant
    Filed: January 31, 1996
    Date of Patent: August 25, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventor: Katsutoshi Nakamura
  • Patent number: 5784140
    Abstract: A liquid crystal display has a pair of transparent electrodes, an anti-ferroelectric liquid crystal therebetween, a polarizer and an analyzer attached to the electrodes. The smectic layers are perpendicular to the electrodes and the liquid crystal has a twisted structure. The directors on the surfaces on the two electrodes are symmetrically aligned with respect to the polarization axis of the polarizer so that the average optical axis of the liquid crystal coincides with the polarization axis of the polarizer. In absence of applied electric field, the incident light through the polarizer passes through the liquid crystal slab with maintaining its polarization. However, when an electric field is applied, the liquid crystal molecules experiences some degree of distortion and the average optical axis rotates. Therefore, the incident light passes through the liquid crystal slab with rotating the polarization.
    Type: Grant
    Filed: December 24, 1996
    Date of Patent: July 21, 1998
    Assignee: Samsung Display Devices Co., Ltd.
    Inventor: Sin-Doo Lee
  • Patent number: 5764327
    Abstract: A ferroelectric liquid crystal device of a cell structure having a suppressed increase of cell thickness along a cell side is constituted by disposing a ferroelectric liquid crystal between a pair of electrode plates each sequentially provided with an electrode, an insulating film and an alignment film on a substrate. The alignment film is provided with a surface unevenness for suppressing a liquid crystal movement causing the increase in cell thickness. The surface unevenness is provided to the alignment film directly or to the insulating film below the alignment film, e.g., by wet forming the relevant film by using at least two solvents having different boiling points or dispersing fine particles within the relevant film, optionally followed by removal of the fine particles.
    Type: Grant
    Filed: October 31, 1996
    Date of Patent: June 9, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yukio Hanyu, Kenji Onuma, Yoshio Hotta, Osamu Taniguchi, Hideaki Takao, Masanobu Asaoka, Tadashi Mihara, Yasuto Kodera, Makoto Kojima, Katsutoshi Nakamura, Takatsugu Wada
  • Patent number: 5754264
    Abstract: A ferroelectric liquid crystal device comprises a layer of a ferroelectric liquid crystal material contained between two cell walls carrying electrode structures and a surface alignment treatment. The surface alignment is provided by a profiled surface, e.g., a grating, on at least one cell wall. The grating may be a monograting or a bigrating, with a symmetric or asymmetric profile. Such a profiling enables surface tilt and alignment anchoring energy to be independently arranged to suit liquid crystal material and device type to give a required molecular arrangement and low device defect. The grating may be provided by interferography, photolithography, embossing, ruling, or carrier layer transfer. Alignment directions on the cell walls may be parallel or non-parallel. The surface tilt on both cell walls may be the same or different values. The cell walls may be relatively rigid, e.g., glass slides, or flexible, e.g.
    Type: Grant
    Filed: August 6, 1996
    Date of Patent: May 19, 1998
    Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventors: Guy Peter Bryan-Brown, Damien Gerard McDonnell, Michael John Towler, John Clifford Jones
  • Patent number: 5748166
    Abstract: The invention concerns a surface stabilized ferroelectric liquid crystal (SSFLC) display devices. Displays are formed by cells containing a thin layer, e.g. 2 .mu.m thick, of smectic liquid crystal material. The cell walls are surface treated and carry e.g. row and column electrodes forming an x,y matrix of addressable display elements or pixels. These devices can show bistability and switch between their two stable state on application of a dc pulse of appropriate polarity, amplitude and width. In this invention the device is addressed by first preconditioning the liquid crystal material at each pixel by applying one of two different levels of ac bias, thereby changing the switching characteristics of the material, and second by a switching with application of a switching pulse. This results in pixels that have received the first of the ac bias levels switching whilst the other pixels do not switch. The two levels of ac bias may be applied e.g.
    Type: Grant
    Filed: March 13, 1996
    Date of Patent: May 5, 1998
    Assignee: The Secretary of State for Defense
    Inventors: Jonathan Rennie Hughes, Michael John Towler
  • Patent number: 5748274
    Abstract: A liquid crystal device comprising a pair of parallel base plates and a ferroelectric liquid crystal disposed between the base plates. One of the pair of parallel base plates is provided with a plurality of stepwise elevations disposed in the form of stripes, and has been implemented with a uniaxial orientation treatment in a direction parallel to the edges of the stepwise elevations. The stepwise elevation may be formed by a transparent electrode alone or in combination with an alignment control film disposed thereon. Because of the above features, alignment defects liable to develop from the edges of the elevations are removed.
    Type: Grant
    Filed: March 20, 1995
    Date of Patent: May 5, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Osamu Taniguchi, Shinjiro Okada, Yutaka Inaba, Hitoshi Shindo, Hirofumi Shibata