Twisted (or Chiral) Nematic Or Supertwisted Nematic Patents (Class 349/179)
  • Patent number: 7551252
    Abstract: The invention provides a bistable twisted nematic liquid crystal display, comprising a first substrate having thereon a first conductive layer and a first alignment layer; a second substrate having thereon a second conductive layer and a second alignment layer; a liquid crystal layer in the first and second alignment layers; an alignment layer on each of the substrates, the alignment layer imparting a preferred direction for liquid crystal molecules near the alignment layer, and possessing different azimuthal and polar anchoring energies when used to align a liquid crystal layer: the alignment layers being rubbed in such a way to give a stable twist angle of the liquid crystal of ? where ? can be any value in between ?45° to +45°; and wherein the d/p ratio of the liquid crystal layer is between the values of 0.15+0.5?/? and 0.35+0.5?/?.
    Type: Grant
    Filed: November 24, 2006
    Date of Patent: June 23, 2009
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Hoi-Sing Kwok, Fion Sze Yan Yeung, Yuet Wing Li
  • Publication number: 20090115958
    Abstract: A liquid crystal display element of the present invention is arranged so that a material layer having dielectric anisotropy includes a chiral material and a liquid crystal material with a nematic liquid crystal phase, and 0.25?d/p?0.50 is satisfied assuming that the thickness of the material layer is d and the chiral pitch length of the liquid crystal material is p.
    Type: Application
    Filed: September 12, 2006
    Publication date: May 7, 2009
    Inventors: Takashi Kurihara, Yasuhiro Kume, Kazuhiko Tamai, Takaaki Okamoto, Shinya Saeki
  • Patent number: 7517566
    Abstract: A liquid crystal composition including at least two kinds of gelling agents and a liquid crystal. The liquid crystal shows a liquid crystal phase at room temperature. A liquid crystal display device using the liquid crystal composition also is provided.
    Type: Grant
    Filed: June 1, 2006
    Date of Patent: April 14, 2009
    Assignee: Konica Minolta Holdings, Inc.
    Inventors: Akihito Hisamitsu, Nobuyuki Kobayashi, Tomoo Izumi
  • Patent number: 7505095
    Abstract: A display panel includes a first substrate, a second a second substrate a second a second substrate parallel and opposite to the first substrate, a liquid crystal molecules disposed between the first substrate and the second substrate, a first and a second polarizers disposed over the first and the second substrates respectively. The first surface of the first substrate close to the liquid crystal molecules and a second surface of the second substrate close to the liquid crystal molecules includes a first alignment surface and a second alignment surface, wherein an angle between the alignment directions of the first and the second alignment surfaces is in a range of about 90°. The angle between a direction of the absorption axis of the first polarizer/the second polarizer and the alignment direction of the first alignment surface/the second alignment surface is in a range of about 45° respectively.
    Type: Grant
    Filed: August 8, 2005
    Date of Patent: March 17, 2009
    Assignee: TPO Displays Corp.
    Inventor: Chi-Huang Lin
  • Publication number: 20080291371
    Abstract: The object of the present invention is to provide a liquid crystal display device having high contrast and excellent viewing angle characteristic which can be manufactured without employing the phase compensation film and with low cost.
    Type: Application
    Filed: February 20, 2008
    Publication date: November 27, 2008
    Applicant: InfoVision Optoelectronics Holdings Limited
    Inventor: Hiroki Sato
  • Patent number: 7407692
    Abstract: A chiral nematic liquid crystal composition, characterized in that a self-organizing type gelling agent is contained and the phase transition temperature between liquid crystal and isotropic phases is higher than the sol-gel transition temperature, a liquid crystal display device wherein the chiral nematic liquid crystal composition is put and held between a pair of substrates having an electrode, and a method for producing a liquid crystal display device wherein the chiral nematic liquid crystal composition is heated to a temperature of not lower than the phase transition temperature between liquid crystal and isotropic phases and then cooled down to room temperature.
    Type: Grant
    Filed: January 25, 2006
    Date of Patent: August 5, 2008
    Assignee: Konica Minolta Holdings, Inc.
    Inventor: Tomoo Izumi
  • Patent number: 7405787
    Abstract: A liquid crystal display is provided which comprises a front panel comprising a front alignment layer having an alignment direction, a rear panel comprising a rear alignment layer having an alignment direction, and a liquid crystal layer between the front and rear alignment layers. The liquid crystal layer has a rotational twist angle of about 90° and a pre-tilt angle of not more then 2°. The alignment, material and thickness of the liquid crystal layer are such that at the mid-point of the rotational twist, the direction of liquid crystal directors coincide with an off-normal viewing direction of the liquid crystal display.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: July 29, 2008
    Assignee: Nitto Denko Corporation
    Inventors: Michael V. Paukshto, Louis D. Silverstein
  • Patent number: 7391485
    Abstract: A dual LCD device includes a liquid crystal panel having a liquid crystal layer interposed between a first substrate and a second substrate, first and second polarizing plates attached to opposing surfaces of the liquid crystal panel, a first front light unit attached to a front side of the liquid crystal panel, and a second front light unit attached to a rear side of the liquid crystal panel.
    Type: Grant
    Filed: March 18, 2004
    Date of Patent: June 24, 2008
    Assignee: LG.Philips LCD Co., Ltd.
    Inventors: Kyeong Jin Kim, Hoon Kang
  • Patent number: 7307685
    Abstract: An electrode is provided on one surface of each of a pair of substrates. On the other surface of each of the substrates, a polarizer is provided. The substrates are assembled together so that their surfaces on which the electrodes are formed face each other. Then, a medium is introduced between the substrates, to form a dielectric material layer. The medium is prepared by mixing a chiral agent in a negative type liquid crystalline compound.
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: December 11, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Koichi Miyachi, Iichiro Inoue, Seiji Shibahara, Shoichi Ishihara
  • Patent number: 7265801
    Abstract: A display panel includes a first substrate, a second a second substrate a second a second substrate parallel and opposite to the first substrate, a liquid crystal molecules disposed between the first substrate and the second substrate, a first and a second polarizers disposed over the first and the second substrates respectively. The first surface of the first substrate close to the liquid crystal molecules and a second surface of the second substrate close to the liquid crystal molecules includes a first alignment surface and a second alignment surface, wherein an angle between the alignment directions of the first and the second alignment surfaces is in a range of about 90°. The angle between a direction of the absorption axis of the first polarizer/the second polarizer and the alignment direction of the first alignment surface/the second alignment surface is in a range of about 45° respectively.
    Type: Grant
    Filed: October 27, 2004
    Date of Patent: September 4, 2007
    Assignee: TPO Displays Corp.
    Inventor: Chi-Huang Lin
  • Patent number: 7259818
    Abstract: A liquid crystal device comprises a nematic liquid crystal, voltage means for applying a voltage across said liquid crystal, and two substrates (42, 30) each provided with an alignment layer (32, 33), wherein: said liquid crystal is sandwiched between said two substrates (42, 30); said nematic liquid crystal can be placed in at least one operating state and at least one non-operating state, and at least one of said alignment layers (32, 33) is provided with a plurality of surface protrusions (40) formed from an anisotropic material.
    Type: Grant
    Filed: March 1, 2002
    Date of Patent: August 21, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Michael John Towler, Elizabeth Jane Acosta
  • Patent number: 7259817
    Abstract: The present invention is configured so that it has a first substrate, a second substrate, a liquid crystal layer pinched between the first substrate and second substrate, and a driving unit, wherein a characteristic of a reflectivity versus an applied voltage is a normally closed type and a characteristic of a transmissivity versus an applied voltage is the normally closed type: wherein the first substrate has a common electrode, and an upside polarization plate and upside phase plate on an upper surface; wherein the second substrate has a reflective electrode and transparent electrode connected with an active element, and a downside polarization plate and downside phase plate on a lower surface; wherein the liquid crystal layer has a twist angle not less than 40 degrees and not more than 65 degrees; wherein a retardation of the liquid crystal layer in a reflective display unit is within a range of not less than 230 nm and not more than 300 nm; and wherein a retardation of the liquid crystal layer in a transm
    Type: Grant
    Filed: August 2, 2002
    Date of Patent: August 21, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Osamu Itou, Hiroko Hayata, Kouichi Anno, Shinichi Komura
  • Patent number: 7253871
    Abstract: An efficient technique for producing deterministically polarized single photons uses liquid-crystal hosts of either monomeric or oligomeric/polymeric form to preferentially align the single emitters for maximum excitation efficiency. Deterministic molecular alignment also provides deterministically polarized output photons; using planar-aligned cholesteric liquid crystal hosts as 1-D photonic-band-gap microcavities tunable to the emitter fluorescence band to increase source efficiency, using liquid crystal technology to prevent emitter bleaching. Emitters comprise soluble dyes, inorganic nanocrystals or trivalent rare-earth chelates.
    Type: Grant
    Filed: January 9, 2004
    Date of Patent: August 7, 2007
    Assignee: University of Rochester
    Inventors: Svetlana G. Lukishova, Robert W. Boyd, Carlos R. Stroud
  • Patent number: 7253861
    Abstract: On substrates 2a, 2b of a chiral nematic liquid crystal optical element 1, transparent electrodes 3a, 3b and electrical insulation layers 4a, 4b are formed, and further, resin layers 5a, 5b hating a pencil hardness of “B” or less are formed on the electrical insulation layers by a spin coating method so as to be in contact with a liquid crystal layer 7. When the surface hardness of the resin layers is to be measured, a glass substrate on which a resin layer is formed by screen-printing is prepared as a test piece, and the test piece is fitted to a pencil-scratching tester. The surface hardness is measured by scratching the test piece with two kinds of testing pencil selected from testing pencils having 17 grades of density.
    Type: Grant
    Filed: December 28, 2001
    Date of Patent: August 7, 2007
    Assignee: Asahi Glass Company
    Inventors: Satoshi Niiyama, Noriko Suehiro
  • Patent number: 7215397
    Abstract: The liquid crystal display device of the present invention includes a pair of substrates, a liquid crystal layer placed between the pair of substrates and an alignment film placed on the side of at least one of the pair of substrates facing the liquid crystal layer. The liquid crystal layer has a first region in which the pretilt direction of liquid crystal molecules of which the alignment is regulated with alignment regulating force of a surface of the alignment film is a first direction and a second region in which the pretilt direction is a second direction different from the first direction. Display is performed using bend alignment of the first region of the liquid crystal layer.
    Type: Grant
    Filed: October 4, 2002
    Date of Patent: May 8, 2007
    Assignees: Sharp Kabushiki Kaisha
    Inventors: Iichiro Inoue, Tatsuo Uchida
  • Patent number: 7167229
    Abstract: An active matrix drive type liquid crystal display element capable of preventing deterioration of display capability caused by a stripe domain, and a projection type display device using the liquid crystal display element, by which there is provided a projection type display device comprising a light source; a light convergence optical system for guiding a light emitted from said light source to a liquid crystal display element; and a projection optical system for enlarging and projecting a light subjected to light modulation by said liquid crystal display element; wherein the liquid crystal display element is configured by holding a liquid crystal layer between a pair of substrates arranged to face to each other, and a twisted nematic type liquid crystal material used in the liquid crystal layer satisfies dielectric constant anisotropy ?? of 0<??<8 and twist elasticity modulus K22 of K22>6.0 pN when the refractive index anisotropy ?n is 0.16??n?0.
    Type: Grant
    Filed: March 28, 2005
    Date of Patent: January 23, 2007
    Assignee: Sony Corporation
    Inventors: Akiko Toriyama, Mieko Suzuki
  • Patent number: 7161647
    Abstract: The invention provides a transflective liquid crystal display device which provides both high-contrast, bright reflective and transmissive displays. The liquid crystal display device of the present invention can include a liquid crystal panel and a backlight. The liquid crystal panel includes a liquid crystal layer, which is disposed between an upper substrate and a lower substrate and whose liquid crystals are disposed in a twisted manner at an angle in the range of from 220 to 270 degrees, an upper retardation film and a lower retardation film, which are disposed above and below the liquid crystal layer so as to sandwich it; an upper polarizer 16 and a lower polarizer, which are disposed on the outer surfaces of their respective retardation films, and a sloping reflective layer. Light impinging upon the upper polarizer from the liquid crystal layer is elliptically polarized light.
    Type: Grant
    Filed: November 5, 2003
    Date of Patent: January 9, 2007
    Assignee: Seiko Epson Corporation
    Inventor: Chiyoaki Iijima
  • Patent number: 7123336
    Abstract: An active matrix drive type liquid crystal display element capable of preventing deterioration of display capability caused by a stripe domain, and a projection type display device using the liquid crystal display element, by which there is provided a projection type display device comprising a light source; a light convergence optical system for guiding a light emitted from said light source to a liquid crystal display element; and a projection optical system for enlarging and projecting a light subjected to light modulation by said liquid crystal display element; wherein the liquid crystal display element is configured by holding a liquid crystal layer between a pair of substrates arranged to face to each other, and a twisted nematic type liquid crystal material used in the liquid crystal layer satisfies dielectric constant anisotropy ?? of 0<??<8 and twist elasticity modulus K22 of K22>6.0 pN when the refractive index anisotropy ?n is 0.16??n?0.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: October 17, 2006
    Assignee: Sony Corporation
    Inventors: Akiko Toriyama, Mieko Suzuki
  • Patent number: 7088413
    Abstract: The invention relates to a bistable nematic liquid-crystal device comprising: alignment means, which orient the liquid crystal, means designed to apply electrical signals which allow switching, by breaking the anchoring on at least one of the two substrates, between two distinct textures, and means designed to promote the establishment of that one of the said textures giving the off state in the liquid crystal covering the inter-electrode spaces.
    Type: Grant
    Filed: August 28, 2002
    Date of Patent: August 8, 2006
    Assignee: Nemoptic
    Inventors: Philippe Martinot-Lagarde, Alain Boissier, Jacques Angele, Bertrand Pecout, Ivan N. Dozov
  • Patent number: 7084939
    Abstract: A normally white supertwist nematic liquid crystal display of reflective type is provided. This display comprises a reflector, a layer of chiral nematic liquid crystal having a front aligning surface facing a light source and a rear aligning surface facing the reflector, and a front polarizer. The nematic liquid crystal has an optical retardation (?nd) of the layer and a distribution of directors, wherein the chiral nematic liquid crystal has a twist angle (?) between an alignment direction of the director at the front aligning surface and an alignment direction of the director at the rear aligning surface. The front polarizer is disposed between the layer of chiral nematic liquid crystal and the light source. The front polarizer has a transmission axis forming an angle (?) with the alignment direction of the director at the front aligning surface of the chiral nematic liquid crystal layer. The optical retardation (?nd) and the angle (?) are defined by the following formulas: ?((?)=sign(?)·(47.0?0.4936|?|+2.
    Type: Grant
    Filed: August 7, 2003
    Date of Patent: August 1, 2006
    Assignee: Nitto Denko Corporation
    Inventors: Michael V. Paukshto, Serguei Palto
  • Patent number: 7068250
    Abstract: A method of addressing multistable nematic liquid crystal devices, in particular bistable nematic liquid crystal devices is provided. The method is a line at a time addressing scheme where one of at least two data waveforms is applied simultaneously to each of the column electrodes whilst a strobe waveform is applied to a row. The strobe waveform comprises a blanking portion sufficient to cause the liquid crystal material to blank, irrespective of which data waveform is applied, immediately followed by a discriminating portion which is such that in combination with an appropriate data waveform allows for selective latching. At least part of both the blanking portion and the discriminating portion are applied during the line address time for the particular row of interest.
    Type: Grant
    Filed: September 5, 2001
    Date of Patent: June 27, 2006
    Assignee: ZBD Displays Limited
    Inventor: John C Jones
  • Patent number: 7019811
    Abstract: The liquid-crystal switching or display device comprises a chiral smectic liquid-crystal mixture, where the ratio ?/? of the angle between the rubbing direction and the smectic layer normal to the tilt angle in the liquid-crystal mixture is at least 0.41. Preferably, the liquid-crystal mixture has the phase sequence I-N-C and the tilt angle ? at 25° C. is between 19° and 39°.
    Type: Grant
    Filed: July 24, 2000
    Date of Patent: March 28, 2006
    Assignee: Clariant International, Ltd.
    Inventors: Hans-Rolf Dübal, Barbara Hornung, Toshiaki Nonaka
  • Patent number: 7015998
    Abstract: A transflective LCD panel has a transmissive region and a reflective region and includes a first substrate, a second substrate opposite to the first substrate, a reflective plate formed on the second substrate and located within the reflective region, and a first liquid crystal layer and a second liquid crystal layer that are filled between the first substrate and the second substrate. The first and second liquid crystal layers correspond to the transmissive and reflective regions, respectively. The second liquid crystal layer is doped with a chiral material. When a voltage is applied, liquid crystal molecules in a middle section of the first liquid crystal layer are substantially arranged in a tilt angle ?, and the liquid crystal molecules of the second liquid crystal layer are tilted by the tilt angle and further twisted.
    Type: Grant
    Filed: June 14, 2004
    Date of Patent: March 21, 2006
    Assignee: AU Optronics Corp.
    Inventor: Ching-Huang Lin
  • Patent number: 7002643
    Abstract: A liquid crystal shutter comprises a liquid crystal device including a nematic liquid crystal sealed in between a first transparent substrate and a second transparent substrate on whose inner surfaces are formed respective transparent electrodes, the liquid crystal device having a twisted angle equal to or greater than 180°; and a pair of polarizing plates between which are sandwiched the first transparent substrate and the second transparent substrate, the polarizing films having respective absorption axes (13, 14) which are substantially orthogonal to each other, the absorption axes (13, 14) of the polarizing films being angled within a range of ±40° to ±50°0 relative to a direction (12) in which intermediate liquid crystal molecules are orientated, the direction indicating a direction of orientation of the liquid crystal in the intermediate portion in the direction of thickness of the liquid crystal device.
    Type: Grant
    Filed: June 25, 2001
    Date of Patent: February 21, 2006
    Assignee: Citizen Watch Co., Ltd.
    Inventors: Yasushi Kaneko, Masaaki Matsunaga
  • Patent number: 6995824
    Abstract: A liquid crystal display device includes a liquid crystal panel, a polarizer plate that is disposed on an observer side, relative to the liquid crystal panel, a polarizer plate that is disposed to be opposed to the polarizer plate, with the liquid crystal panel interposed, and an optical film that is disposed between the polarizer plate and the liquid crystal panel and between the polarizer plate and the liquid crystal panel, thereby to increase a viewing angle of an image that is displayed by the liquid crystal panel, wherein a twist angle of the liquid crystal molecules sealed in the liquid crystal panel is greater than 90° and not greater than 96°, a retardation ?nd of the liquid crystal panel is between 400 nanometers (nm) and 430 nm, and a retardation ?nd of the optical film is between 110 nm and 120 nm.
    Type: Grant
    Filed: November 24, 2004
    Date of Patent: February 7, 2006
    Assignee: Toshiba Matsushita Display Technology Co., Ltd.
    Inventor: Kazuhiro Joten
  • Patent number: 6975372
    Abstract: Methods and systems relating to a LCD are disclosed. In one exemplary embodiment, the LCD has an active state and an inactive state. The inactive state is configured to produce a desired residual image. The active state is configured to produce a desired non-residual image.
    Type: Grant
    Filed: September 23, 2002
    Date of Patent: December 13, 2005
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Michael D Long
  • Patent number: 6927765
    Abstract: A display device which has a liquid crystal display having a liquid crystal material, a driver for driving the liquid crystal display, and a controller for controlling the driver to drive at least a part of the liquid crystal display by selectively using one of a first drive method and a second drive method which are different from each other in operational principle of the liquid crystal material. The pulse voltage to drive at least one pixel of the liquid crystal display can be selectively set to any one of a plurality of kinds. The data pulse voltage applied to a data electrode can be selectively set to any one of a plurality of kinds to drive at least one pixel of the liquid crystal.
    Type: Grant
    Filed: November 12, 1999
    Date of Patent: August 9, 2005
    Assignee: Minolta Co., Ltd.
    Inventors: Naoki Masazumi, Eiji Yamakawa, Hideo Hotomi
  • Patent number: 6900469
    Abstract: Disclosed is a liquid crystal display apparatus comprising a pair of substrates and a liquid crystal layer provided between the substrates, the liquid crystal layer containing a liquid crystal composition that exhibits a cholesteric phase. The liquid crystal composition contains a mixture of a chiral material and nematic liquid crystal. The liquid crystal display layer is configured to satisfies the following conditions: a viscosity a [cP] of the liquid crystal composition is in a range from 30 to 150; a dielectric anisotropy b of the liquid crystal composition is in a range from 5 to 50; a thickness c [?m] of the liquid crystal layer is in a range from 3 to 8; and a product of a, b, and c is not less than 3500.
    Type: Grant
    Filed: September 19, 2001
    Date of Patent: May 31, 2005
    Assignee: Minolta Co., Ltd.
    Inventors: Takeshi Kitahora, Akihito Hisamitsu, Hideaki Ueda, Mitsuyo Matsumoto
  • Patent number: 6867427
    Abstract: Molecular systems are provided for electric field activated switches, such as optical switches. The molecular system has an electric field induced band gap change that occurs via one of the following mechanisms: (1) molecular conformation change; (2) change of extended conjugation via chemical bonding change to change the band gap; or (3) molecular folding or stretching. Nanometer-scale reversible optical switches are thus provided that can be assembled easily to make a variety of optical devices, including optical displays.
    Type: Grant
    Filed: July 10, 2003
    Date of Patent: March 15, 2005
    Assignee: Hewlett-Packard Development Company, LP.
    Inventors: Sean Xiao-An Zhang, R. Stanley Williams, Kent D. Vincent
  • Patent number: 6856086
    Abstract: A display includes a front panel and a back panel with a light control material in between. One of the panels includes a rigid substrate, for example made of glass or rigid plastic. The other of the panels includes a flexible substrate, for example made of a flexible plastic film. The panel with the flexible substrate may be made by a roll-to-roll process, with various fabrication operations formed while the flexible substrate is still part of a web of material. The panel with the rigid substrate may be separately fabricated, then combined with the other panel on the web through a pick and place operation that accurately locates the front panel relative to the back panel. The display may be any of a variety of displays, such as liquid crystal displays (LCDs), and electroluminescent displays, such as polymer light emitting devices (PLEDs) and organic light emitting devices (OLEDs).
    Type: Grant
    Filed: September 24, 2001
    Date of Patent: February 15, 2005
    Assignee: Avery Dennison Corporation
    Inventors: Anthony J. Grace, Kieran F. Drain, Yukihiko Sasaki
  • Patent number: 6856373
    Abstract: A liquid crystal display apparatus includes a liquid crystal display unit, a plurality of data driving units which provide image data to said liquid crystal display unit, and a control unit which enables said plurality of data driving units to take in the image data simultaneously if the image data to be provided to said data driving units are identical.
    Type: Grant
    Filed: August 27, 2001
    Date of Patent: February 15, 2005
    Assignee: Fujitsu Display Technologies Corporation
    Inventors: Satoshi Sekido, Takae Ito, Shinpei Nagatani, Hidefumi Yoshida, Takashi Sasabayashi, Koichi Katagawa, Katsuhiko Kishida, Mikio Oshiro, Katsunori Tanaka, Toshimitsu Minemura, Katsuyoshi Hiraki, Yuichi Inoue
  • Patent number: 6836306
    Abstract: A transflective liquid crystal display device having excellent display quality is provided which is capable of precisely controlling the alignment of liquid crystal molecules and of providing a high brightness display both in a transmissive display mode and in a reflective display mode. The transflective liquid crystal display panel has a pair of substrates, a liquid crystal layer sandwiched between the substrates, pixel electrodes disposed on the surface of one of the substrates facing the liquid crystal layer, a counter electrode disposed on the surface of the other substrate facing the liquid crystal layer, and an alignment film covering the surface of each of the substrates facing the liquid crystal layer. The pixel electrodes, each including an electrode for reflective display and an electrode for transmissive display, are disposed such that the distances to the other substrate from the electrode for reflective display and from the electrode for transmissive display are different.
    Type: Grant
    Filed: January 9, 2004
    Date of Patent: December 28, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hirofumi Kubota, Naohide Wakita, Tsuyoshi Uemura, Sadayoshi Hotta
  • Publication number: 20040252272
    Abstract: A relation between a twist pitch p of twisted nematic liquid crystal and a thickness d of a liquid crystal layer is set to p/d<8, and polymer stabilization is carried out. In this way, torque to recover from alignment upon application of a voltage to alignment without application of the voltage is increased and response speed of the liquid crystal at decay time is thereby increased. By applying the present technique to a liquid crystal display device which is driven by a reset operation, an overdrive operation or common modulation, high response speed is obtained even when the twisted nematic liquid crystal is used. As a result, the liquid crystal display device can deal with field sequential display mode where higher response speed is required.
    Type: Application
    Filed: June 16, 2004
    Publication date: December 16, 2004
    Applicant: NEC CORPORATION
    Inventors: Kenichi Takatori, Kossikhna A. Svetlana
  • Patent number: 6801291
    Abstract: The invention provides a liquid crystal device capable of obtaining a bright image with a high display quality by controlling disclination caused by a lateral electric field developed across a space between pixels, or the like.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: October 5, 2004
    Assignee: Seiko Epson Corporation
    Inventor: Kinya Ozawa
  • Patent number: 6800338
    Abstract: To provide an electro-optical liquid-crystal displays with low addressing voltages and low to moderate multiplex ratios, in particular STN displays, organic alignment layers of low layer thickness are utilized.
    Type: Grant
    Filed: April 16, 2001
    Date of Patent: October 5, 2004
    Assignee: Merck Patentgesellschaft
    Inventors: Thomas Jacob, Juliane Suermann
  • Patent number: 6795155
    Abstract: The invention provides a liquid crystal device capable of obtaining a bright image with a high display quality by controlling disclination caused by a lateral electric field developed across a space between pixels, or the like.
    Type: Grant
    Filed: November 21, 2003
    Date of Patent: September 21, 2004
    Assignee: Seiko Epson Corporation
    Inventor: Kinya Ozawa
  • Patent number: 6784968
    Abstract: A bistable nematic liquid crystal device is addressed by application of a row waveform to successive row electrodes of an x, y matrix of pixels whilst one of two data waveforms are applied to each column electrode. The row waveform has a period of two or more time slots (ts), with two dc pulses of opposite amplitude for causing a switching to a dark state, and two dc pulses of opposite amplitude for causing a switching to a light state. The data waveforms have the same period as the strobe with dc pulses of opposite amplitude and combine with the strobe pulses to switch the device. The device can be addressed in two field periods, one field switching to a dark state, the other field switching to a light state. Alternatively, the device can be blanked to the dark state then selectively switched to the light state. When blanking is used, the row waveform has blanking de pulses placed a short time before selective switching to reduce overall addressing time.
    Type: Grant
    Filed: September 13, 2001
    Date of Patent: August 31, 2004
    Assignee: ZBD Displays Limited
    Inventors: Jonathan R Hughes, John C Jones, Guy P Bryan-Brown, Alistair Graham
  • Patent number: 6784955
    Abstract: The structure and construction of a bistable twisted nematic liquid crystal display with very long lifetime are disclosed. The two stable twist states in this display when no voltage is applied have almost infinite lifetimes and do not decay. These two stable twist states differ by a twist angle of 180°. New design conditions of this bistable twist structure are disclosed such that the contrast and the brightness are both optimized. This display can be operated in transmittive mode with two polarizes or in the reflective mode with one polarizer.
    Type: Grant
    Filed: October 1, 2001
    Date of Patent: August 31, 2004
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Hoi-Sing Kwok, Jian-Xin Guo
  • Patent number: 6774977
    Abstract: A surface mode liquid crystal device, for example of the pi-cell type, comprises a layer nematic liquid crystal (10) disposed between alignment layers (4,9) and an electrode arrangement (3,8). The nematic liquid crystal has viscosity coefficients &eegr;1, &eegr;2 and &ggr;1, such that (&eegr;1-&eegr;2)/&ggr;1≧1.15 or (&eegr;1-&eegr;2)/&ggr;1≦0.9.
    Type: Grant
    Filed: June 7, 2002
    Date of Patent: August 10, 2004
    Assignee: Sharp Laboratories of Europe Limited
    Inventors: Harry Garth Walton, Michael John Towler
  • Publication number: 20040135961
    Abstract: A liquid crystal display has two substrates (100, 200) opposite to each other and spaced apart a predetermined distance, a liquid crystal layer (300) between the two substrates and having a plurality of liquid crystal molecules (310), and a pair of electrodes (121, 122) formed on one of the substrates to provide an electrical field parallel to the substrates. Each substrate has an alignment layer formed thereon. Each alignment layer has a plurality of parallel grooves (190, 240) on its surface to orient the liquid crystal molecules. The grooves of one alignment layer are orthogonal to the grooves of the other alignment layer. When no voltage is provided, the overall arrangement of the liquid crystal molecules comprises a 90° twist. When a voltage is applied to the electrodes, an electrical field parallel to the substrate is formed, which rotates the liquid crystal molecules and makes the arrangement of the liquid crystal molecules homogeneous.
    Type: Application
    Filed: December 22, 2003
    Publication date: July 15, 2004
    Inventors: Ga-Lane Chen, Charles Leu, Tai-Cheng Yu
  • Patent number: 6753045
    Abstract: The invention relates to TN and STN liquid-crystal displays and to the novel nematic liquid-crystal mixtures used therein, characterized in that they comprise one or more compounds of the formula I and at least one compound of the formula II and at least one compound of the formula III in which R1, R2, R3, R4, L1, L2 and X are as defined in claim 1.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: June 22, 2004
    Assignee: Merck Patent GmbH
    Inventor: Juliane Suermann
  • Publication number: 20040085508
    Abstract: A normally white supertwist nematic liquid crystal display of reflective type is provided. This display comprises a reflector, a layer of chiral nematic liquid crystal having a front aligning surface facing a light source and a rear aligning surface facing the reflector, and a front polarizer. The nematic liquid crystal has an optical retardation (&Dgr;nd) of the layer and a distribution of directors, wherein the chiral nematic liquid crystal has a twist angle (&PHgr;) between an alignment direction of the director at the front aligning surface and an alignment direction of the director at the rear aligning surface. The front polarizer is disposed between the layer of chiral nematic liquid crystal and the light source. The front polarizer has a transmission axis forming an angle (&agr;) with the alignment direction of the director at the front aligning surface of the chiral nematic liquid crystal layer.
    Type: Application
    Filed: August 7, 2003
    Publication date: May 6, 2004
    Inventors: Michael V. Paukshto, Serguei Palto
  • Patent number: 6707527
    Abstract: The present invention provides the conditions for new bistable twisted nematic liquid crystal displays, in particular the necessary twist angles, liquid crystal retardation values, input and output polarizer angles, for both transmissive and reflective liquid crystal displays.
    Type: Grant
    Filed: May 19, 2000
    Date of Patent: March 16, 2004
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Hoi-Sing Kwok, Shu-Tuen Tang
  • Patent number: 6697129
    Abstract: A liquid crystal display device comprising a light modulating layer being interposed between a first substrate and a second substrate, a common electrode being formed over the first substrate in parallel with a drain electrode, wherein an electric field is formed between the drain electrode and the common electrode in a parallel direction to the first substrate, wherein said light modulating layer comprising a liquid crystal material, an optically active substance and a dichroic dye is operated in a guest-host mode, wherein said liquid crystal material has a spiral pitch p in a range of 1<p<15 &mgr;m, and wherein a cell thickness d is in a range of 1<d<10 &mgr;m.
    Type: Grant
    Filed: March 29, 1999
    Date of Patent: February 24, 2004
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Takeshi Nishi, Rumo Satake, Yoshiharu Hirakata
  • Patent number: 6693695
    Abstract: At least one of a pair of substrates constituting a liquid crystal device is provided with a composite alignment film including a homeotropic alignment film region and a homogeneous alignment film region, whereby the liquid crystal in contact with the homogeneous alignment film region is surrounded by the region of liquid crystal in a hybrid or homeotropic alignment state and is stably held in a twit alignment state under no electric field which can be continuously transformed into a bend alignment state. As a result, it is possible to provide a liquid crystal device capable of display by utilizing bend alignment with reduced bending voltage and voltage for holding the bend alignment.
    Type: Grant
    Filed: January 14, 2003
    Date of Patent: February 17, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinjiro Okada, Hirohide Munakata, Akira Tsuboyama, Yasuyuki Watanabe, Yasufumi Asao
  • Publication number: 20040022962
    Abstract: A film for a liquid crystal display comprising a fatty acid cellulose ester film having an acetyl group and a propionyl group is disclosed. Sum of degree of acetyl substitution (DSac) and degree of propionyl substitution (DSpr) of the fatty acid cellulose ester film of the film is 2.8 or less, and a retardation value (Rt value) in the thickness direction defined by Formula 1 is 60 to 300 nm.
    Type: Application
    Filed: July 18, 2003
    Publication date: February 5, 2004
    Applicant: Konica Corporation
    Inventors: Toshiaki Shibue, Makoto Honda, Nobuo Kubo, Noriyasu Kuzuhara, Hiroki Umeda, Sota Kawakami, Takatoshi Yajima
  • Patent number: 6669999
    Abstract: A method for making broadband cholesteric liquid crystals with improved bandwidth. The method includes the main steps of: (a) preparing a polymerization mixture containing first and second chiral liquid crystals, wherein the first chiral liquid crystal possesses a cholesteric liquid crystal phase and the second chiral liquid crystal possesses a helix-inversion characteristic, and at least one of the first or second chiral liquid crystals contains a polymerizable functional group; and (b) subjecting the polymerization mixture to a polymerization reaction, wherein the polymerization reaction is conducted such that the first chiral liquid crystal will go through a helix-inversion phenomenon. In a preferred embodiment, the second chiral liquid crystal has a temperature-dependent helicity which exhibits a helix inversion characteristic at a helix inversion temperature.
    Type: Grant
    Filed: May 30, 2001
    Date of Patent: December 30, 2003
    Assignee: Industrial Technology Research Institute
    Inventors: Pao-Ju Hsieh, Hui-Lung Kuo
  • Patent number: 6654093
    Abstract: A reflective liquid crystal display device includes: first and second substrates spaced apart and facing each other; a twisted nematic liquid crystal layer sandwiched between the two substrates, the liquid crystal layer having a twist angle and birefringence property &Dgr;n and having a thickness d; a retardation film disposed on the first substrate and opposite to the liquid crystal layer, the film converting a first linearly polarized light from above to a first circularly polarized light and converting a second circularly polarized light reflected from below to a second linearly polarized light; a linear polarizer disposed on the retardation film and opposite to the liquid crystal layer and converting the incident light to the first linearly polarized light; and a reflector disposed between the liquid crystal layer and the second substrate and reflecting light passed through the liquid crystal layer.
    Type: Grant
    Filed: May 16, 2000
    Date of Patent: November 25, 2003
    Assignee: LG. Philips LCD Co., Ltd.
    Inventor: Woohyun Kim
  • Patent number: 6642980
    Abstract: A display device with a liquid crystal cell including a layer of twisted nematic liquid crystal placed between two polarizers and including, between the liquid crystal layer and each of the polarizers, a structure for compensating for cell contrast variations according to the observation angle which has an orientation in the plane of the cell. The pass directions of the polarizers are separated by an angle of 90+A degrees, in which A is not zero, and the orientations of the two compensation structures are separated by an angle of 90+B degrees, in which B is not zero. Such a structure may find particular application to a liquid crystal screen, especially for avionics.
    Type: Grant
    Filed: October 13, 2000
    Date of Patent: November 4, 2003
    Assignee: Thomson-CSF Sextant
    Inventors: Laurent Bignolles, Frédéric de Lauzun, Laurent Georges, Jean-Jacques Laborie
  • Patent number: 6620467
    Abstract: A supertwisted nematic liquid crystal display having twist angle of 180 to 270° C. and comprising: a pair of substrates each having an orientation-controlling layer and a transparent electrodel; a liquid crystal layer comprising a liquid crystal composition, which is sandwiched by the substrates; and at least one polarizing sheet provided on at least one of the substrates, wherein the liquid crystal composition comprises: at least one compound represented by formula (I): and at least one compound represented by formula (II): and wherein said liquid crystal composition has a nematic-isotropic phase transition temperature of 75 to 150° C. and a refractive index anisotropy (&Dgr;n) of 0.07 to 0.25. The symbols in formulae (I) and (II) are defined in the specification.
    Type: Grant
    Filed: July 25, 2001
    Date of Patent: September 16, 2003
    Assignee: Dainippon Ink and Chemicals, Inc.
    Inventors: Go Sudo, Shotaro Kawakami, Haruyoshi Takatsu, Hiroyuki Ohnishi, Naoe Katoh