Within Chiral Smectic Phase (includes Ferroelectric) Patents (Class 349/172)
  • Patent number: 6614491
    Abstract: There is provided a liquid crystal display which is capable of preventing light from leaking out from the peripheral portion of pixels and which has a high display performance.
    Type: Grant
    Filed: March 9, 2001
    Date of Patent: September 2, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Rei Hasegawa, Rieko Fukushima, Tatsuo Saishu, Hajime Yamaguchi, Kohki Takatoh
  • Publication number: 20030156243
    Abstract: A liquid crystal layer is formed by filling a space between alignment films provided on both glass substrates with a ferroelectric liquid crystal material having a spontaneous polarization. This ferroelectric liquid crystal exhibits a monostable state in which the average molecular axis of the liquid crystal molecular director is present in substantially one direction in the absence of an applied voltage. When a voltage of a first polarity is applied, the average molecular axis tilts from the monostable position to one side at an angle corresponding to the magnitude of the applied voltage, while, when a voltage of a second polarity having the opposite characteristic to the first polarity is applied, the average molecular axis tilts from the monostable position to a side opposite to the application of the voltage of the first polarity. A maximum tilt angle in the application of the voltage of the first polarity is not less than 35°, more preferably not less than 450°.
    Type: Application
    Filed: January 16, 2003
    Publication date: August 21, 2003
    Applicant: FUJITSU LIMITED
    Inventors: Toshiaki Yoshihara, Hironori Shiroto, Tetsuya Makino, Keiichi Betsui
  • Patent number: 6605323
    Abstract: In a monostable ferroelectric active matrix display comprising a liquid-crystal layer in the form of a monodomain having an unambiguously defined direction of the layer normals z of the smC* phase, the layer normals z and the preferential direction n of the nematic or cholesteric phase (N* phase) form an angle of more than 5°.
    Type: Grant
    Filed: April 23, 2001
    Date of Patent: August 12, 2003
    Assignee: Aventis Research & Technologies GmbH & Co. KG
    Inventors: Rainer Wingen, Barbara Hornung, Toshiaki Nonaka
  • Patent number: 6600544
    Abstract: A liquid crystal layer is formed by filing the space between alignment films formed on two glass substrates, respectively, with a ferroelectric liquid crystal having spontaneous polarization. When the maximum charge amount injected to each pixel by the switching of a switching element, the area of each pixel electrode and the magnitude of the spontaneous polarization of the ferroelectric liquid crystal per unit area are denoted as Q, A, and PS, respectively, the relation 2PS·A>Q is established. A cone angle 2&thgr; (&thgr;: tilt angle) of the ferroelectric liquid crystal is not smaller than 45°. It is possible to use a liquid crystal material having large spontaneous polarization, and a high-speed response is realized even when a low voltage is applied to the liquid crystal material.
    Type: Grant
    Filed: December 20, 2001
    Date of Patent: July 29, 2003
    Assignee: Fujitsu Limited
    Inventors: Toshiaki Yoshihara, Keiichi Betsui, Hironori Shiroto
  • Patent number: 6599442
    Abstract: Helical arrays comprising structurally different chiral non-racemic molecules or molecular entities that control the helical sense of the helical array provide a method for temperature measurement with a unique characteristic in that the temperature dependent chiral biases of the competing structurally different chiral non-racemic entities control the helical sense population since these biases differ in their temperature dependence. By varying the composition of the chiral non-racemic entities, the temperature at which the helical sense population is equal and how the helical sense population varies as a function of temperature can be controlled. In this way, competing structurally different non-racemic chiral groups can be varied in their composition so that a helical array can be formed under their effect and be sensitive to temperature over a wide temperature range.
    Type: Grant
    Filed: February 26, 2001
    Date of Patent: July 29, 2003
    Assignee: Polytechnic University
    Inventor: Mark M. Green
  • Publication number: 20030107701
    Abstract: A liquid crystal display device of the present invention includes: a pair of substrates for which a homeotropic alignment treatment is performed; a liquid crystal layer provided between the substrates; and a transverse electric field generating electrode capable of being driven in a matrix driving manner which is provided on at least one of the pair of substrates and is connected to external control means. A liquid crystal material contained in the liquid crystal layer is a liquid crystal material which, as a whole liquid crystal layer, generates spontaneous polarization by a piezoelectric effect.
    Type: Application
    Filed: October 23, 2002
    Publication date: June 12, 2003
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Fumikazu Shimoshikiryo, Shuichi Kozaki, Koichi Miyachi
  • Patent number: 6577369
    Abstract: A liquid crystal display having a transparent electrode layer is free from interference fringes and image sticking are disclosed. The transparent electrode layer may consist of a first transparent film, a transparent electrode film, a second transparent non-conductive film and a transparent conductive film, the films being laminated on a transparent electrode substrate in order in which the transparent conductive film has an extended portion that reaches the transparent electrode film so that the transparent conductive film is electrically coupled to the transparent electrode film via the extended portion. Or, the transparent electrode layer may consist of a first transparent film, a transparent electrode film and a second transparent film, the films being laminated on a transparent electrode substrate in order in which the second transparent film has resistivity low enough to transfer charges to the transparent electrode film.
    Type: Grant
    Filed: June 25, 2001
    Date of Patent: June 10, 2003
    Assignee: Victor Company of Japan, Ltd.
    Inventor: Masanobu Shigeta
  • Patent number: 6573970
    Abstract: An object of the present invention is to provide a liquid crystal display-device with a high degree of light utilization efficiency (a high numerical aperture), and for which a rapid response is possible at high contrast. A liquid crystal display device incorporating at least one compound with optical activity for which the value of the spontaneous polarization is positive, and at least one compound with optical activity for which the value of the spontaneous polarization is negative, and for which the overall spontaneous polarization may be either positive or negative, is prepared, and is then held between substrates which incorporate electrodes.
    Type: Grant
    Filed: July 14, 2000
    Date of Patent: June 3, 2003
    Assignee: NEC Corporation
    Inventors: Goroh Saitoh, Ken-ichi Takatori
  • Patent number: 6573879
    Abstract: A plasma-addressed liquid crystal display device capable of high-speed drive and improved viewing characteristic is composed of a liquid crystal cell structure and plasma cell structure stacked with each other. The liquid crystal cell structure is formed by sandwiching a liquid crystal having a spontaneous polarization between a first transparent substrate having therein transparent electrode stripes and an alignment film covering the electrode stripes, and a dielectric sheet having thereon an alignment film. The plasma cell structure is formed of a second transparent substrate having thereon cathode stripes and anode stripes disposed alternately with a spacing therebetween, stacked via stripe-shaped partitions disposed along the anode stripes onto the dielectric sheet so as to form plasma channels between the partitions filled with an ionizable gas sealed up therein.
    Type: Grant
    Filed: August 17, 2001
    Date of Patent: June 3, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Osamu Taniguchi, Akira Tsuboyama
  • Publication number: 20030098945
    Abstract: A light deflection element has a pair of transparent substrates 2, 3; a chiral smectic C phase liquid crystal 5 with a homeotropic alignment filled between the pair of transparent substrates 2, 3; and at least an electric field applying device 6 for activating an electric field in the liquid crystal 5. Because a chiral smectic C phase liquid crystal is used, the problems of the conventional light deflection element, such as high cost, light loss, large size, and optical noise etc. due to its complicated structure, can be greatly improved. The conventional low response time due to the smectic A phase or the nematic liquid crystal is improved, thereby the high-speed response is possible.
    Type: Application
    Filed: September 12, 2002
    Publication date: May 29, 2003
    Inventors: Hiroyuki Sugimoto, Toshiaki Tokita, Yumi Matsuki, Shigeaki Nimura, Masanori Kobayashi, Yasuyuki Takiguchi, Kenji Kameyama, Ikuo Katoh
  • Patent number: 6559919
    Abstract: In the manufacture of a ferroelectric liquid crystal cell, alignment layers provided on the inside surfaces of the substrate structures for imparting a preferred alignment to the molecules of the liquid crystal layer in the vicinity of the layers are formed by deposition of two different alignment solutions, such as LQT120 and JALS212 for example, on the substrate structures. A mixture of the alignment solutions was applied by spin coating and subsequently the solvent was evaporated by prebaking prior to a further baking step and a rubbing step to impart a preferred alignment direction. The resulting alignment layers have a speckled structure in which areas of one type are interspersed within areas of another type. The different areas have different alignment properties which serve to control switching of molecules of the liquid crystal material between alignment states in response to an applied electric field.
    Type: Grant
    Filed: May 25, 1999
    Date of Patent: May 6, 2003
    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
    Inventor: Rachel Patricia Tuffin
  • Patent number: 6559918
    Abstract: The liquid crystal display has a liquid crystal cell (15) containing a bistable ferroelectric liquid crystal (12). The liquid crystal cell (15) is a quarter wave cell and includes two opposing covering electrodes (13) arranged in a flexible, preferably plastic, substrate (11) on opposite sides of the bistable ferroelectric liquide crystal (12) and spacers (16) distributed between the covering electrodes (13). A diffuser or reflector (18) is arranged on a rear side of the substrate (11) so that light passes twice through the liquid crystal cell (15). The bistable liquid crystal display with the quarter wave liquid crystal cell is flexible but mechanically stable to mechanical impacts, torsion and bending. Orienting layers (14) for the liquid crystal are applied obliquely or diagonally to the surface of the substrate.
    Type: Grant
    Filed: April 2, 1999
    Date of Patent: May 6, 2003
    Assignee: Institut fuer Netzwerk- und Systemtheorie Labor fuer Bildschirmtechnik
    Inventor: Ernst Lueder
  • Patent number: 6551669
    Abstract: The present invention provides a monostable ferroelectric liquid crystal display apparatus includes a pair of substrates, each subjected to uniaxial orientation processing and arranged so that their orientation processing directions are approximately parallel to each other; and a ferroelectric liquid crystal material having the chiral smectic C phase filled between the substrates, the liquid crystal material being such that the projection component of the cone drawn by a liquid crystal molecule of the ferroelectric liquid crystal material projected onto the substrate and the projection component of the liquid crystal molecule itself projected onto the substrate in the molecule axis direction are respectively identical to the orientation processing direction of the substrates, which state is the initial state of the monostable configuration, wherein the ferroelectric liquid crystal contains a compound having a phenyl pyrimidine skeleton having one end connected to an alkoxyl chain and the other end connected t
    Type: Grant
    Filed: February 15, 2001
    Date of Patent: April 22, 2003
    Assignee: Sony Corporation
    Inventors: Teiichiro Nishimura, Makoto Jisaki, Tadaaki Isozaki, Eiji Okabe, Ryushi Shundo, Hideo Saito
  • Patent number: 6545738
    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: Grant
    Filed: June 29, 2001
    Date of Patent: April 8, 2003
    Assignee: LG.Philips LCD Co., Ltd.
    Inventors: Hyeon Ho Son, Su Seok Choi, Jong Jin Park
  • Publication number: 20030011739
    Abstract: A liquid crystal layer is formed by filing the space between alignment films formed on two glass substrates, respectively, with a ferroelectric liquid crystal having spontaneous polarization. When the maximum charge amount injected to each pixel by the switching of a switching element, the area of each pixel electrode and the magnitude of the spontaneous polarization of the ferroelectric liquid crystal per unit area are denoted as Q, A, and PS, respectively, the relation 2PS·A>Q is established. A cone angle 2&thgr; (&thgr;: tilt angle) of the ferroelectric liquid crystal is not smaller than 45°. It is possible to use a liquid crystal material having large spontaneous polarization, and a high-speed response is realized even when a low voltage is applied to the liquid crystal material.
    Type: Application
    Filed: December 20, 2001
    Publication date: January 16, 2003
    Applicant: FUJITSU LIMITED
    Inventors: Toshiaki Yoshihara, Keiichi Betsui, Hironori Shiroto
  • Patent number: 6498632
    Abstract: A color, high-throughput, ferroelectric liquid crystal-based light valve comprising a light input, a light output, a beam splitter, a color separator, reflective spatial light modulators, and a switchable half-wave plate. Light polarized parallel to a first direction is received through the light input. Light from the light input and reflected by the spatial light modulators is output from the light output. The reflective spatial light modulators are structured as a quarter-wave plates and each has a principal axis that switches through an angle &phgr;. The beam splitter has orthogonal directions of maximum transmissivity and maximum reflectivity, one of which is parallel to the first direction.
    Type: Grant
    Filed: April 27, 1999
    Date of Patent: December 24, 2002
    Assignee: Hewlett-Packard Company
    Inventors: Mark M. Butterworth, Rene P. Helbing
  • Patent number: 6496170
    Abstract: A liquid crystal apparatus comprises: a liquid crystal device including a liquid crystal having a spontaneous polarization and causing a state change accompanied with a polarity inversion thereof within a response time. Drive means sequentially selects scanning signal lines each in a scanning selection period and applies data signal voltages to the pixels along an associated scanning signal line, wherein the scanning selection period for a scanning signal line is shorter than the response time for the liquid crystal at a pixel on the scanning signal line thus being liable to leave a remaining portion of polarity inversion to reach a desired state change, and the data signal voltage applied to the pixel is set to include a compensation voltage for compensating for a voltage decrease caused by the remaining portion of polarity inversion.
    Type: Grant
    Filed: April 29, 1999
    Date of Patent: December 17, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akio Yoshida, Katsumi Komiyama, Takashi Enomoto
  • Publication number: 20020180925
    Abstract: An organic electroluminescence device is made to show an improved carrier transporting ability and an improved carrier injecting property by doping a liquid crystal compound having a high degree of carrier mobility without generating any ionic current. The organic electroluminescence device comprises a carrier transport layer formed by doping a smectic liquid crystal compound having a hexagonal order structure with a Lewis acid compound, a light-emitting layer and a protection layer arranged between the carrier transport layer and the light-emitting layer and composed of an organic compound having a carrier transporting property of the same type as that of carrier transport layer and a carrier conducting property of the type different from that of the carrier transport layer.
    Type: Application
    Filed: May 23, 2002
    Publication date: December 5, 2002
    Inventors: Akira Tsuboyama, Shinjiro Okada, Takao Takiguchi, Seishi Miura, Takashi Moriyama, Jun Kamatani, Manabu Furugori
  • Patent number: 6482479
    Abstract: An active matrix display comprises a chiral smectic liquid crystal mixture which has the phase sequence I—N*—SmC*, a spontaneous polarization in the operating temperature range of <40 nC/cm2 and a pitch of >10 &mgr;m at at least one temperature in the nematic or cholesteric phase and comprises at least one compound each from at least two of the substance classes (A), (B) and (C) and one or more compounds from substance class (D): (A): compounds comprising two rings which are directly linked to one another and are selected from phenylene-1,4-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl and pyridazine-2,5-diyl with the proviso that at least one of these rings is a nitrogen heterocycle; (B): compounds comprising three rings selected from phenylene-1,4-diyl, two of the rings being directly linked to one another and the third ring being linked to one of the other two rings via an —OC(═O)— or —C(═O)—group, with the proviso that at least one of the three rings is
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: November 19, 2002
    Assignee: Clariant International Ltd.
    Inventors: Hans-Rolf Dübal, Toshiaki Nonaka, Rainer Wingen
  • Publication number: 20020135729
    Abstract: A light deflection element has a pair of transparent substrates 2, 3; a chiral smectic C phase liquid crystal 5 with a homeotropic alignment filled between the pair of transparent substrates 2, 3; and at least an electric field applying device 6 for activating an electric field in the liquid crystal 5. Because a chiral smectic C phase liquid crystal is used, the problems of the conventional light deflection element, such as high cost, light loss, large size, and optical noise etc. due to its complicated structure, can be greatly improved. The conventional low response time due to the smectic A phase or the nematic liquid crystal is improved, thereby the high-speed response is possible.
    Type: Application
    Filed: January 23, 2002
    Publication date: September 26, 2002
    Inventors: Toshiaki Tokita, Kenji Kameyama, Ikuo Katoh, Hiroyuki Sugimoto, Yasuyuki Takiguchi
  • Patent number: 6456357
    Abstract: A liquid crystal display device comprises a pair of substrates on whose opposing surfaces electrodes are formed; and a liquid crystal provided between the substrates and having spontaneous polarization and a physical property such that when a positive or negative saturation voltage whose absolute value is sufficiently large is applied between the electrodes, liquid crystal molecules are aligned in a first direction or a second direction, and when an arbitrary voltage lying between the positive saturation voltage and the negative saturation voltage is applied between the electrodes, a director is aligned in an arbitrary direction which corresponds to the applied voltage and which lies in a cone angle formed by the first direction and the second direction.
    Type: Grant
    Filed: December 27, 2000
    Date of Patent: September 24, 2002
    Assignee: Casio Computer Co., Ltd.
    Inventor: Jun Ogura
  • Patent number: 6456349
    Abstract: A ferroelectric liquid crystal element comprises a ferroelectric liquid crystal and a pair of substantially parallel substrates having opposite surfaces between which the ferroelectric liquid crystal is sealed. The substrates are provided with electrodes to which voltages are applied, and are subjected to one axis orientation treatment so as to orient the ferroelectric liquid crystal. The ferroelectric liquid crystal has an orientation state represented by the following condition: &thgr;<&agr;+&dgr; wherein &agr; is a pretilt angle of the ferroelectric liquid crystal, &thgr; is a tilt angle, and &dgr; is an inclination angle of an Sm*C layer. The ferroelectric liquid crystal exhibits at least two stable states in orientation. An angle &thgr;a ½ between optical axes of these two stable states and the tilt angle &thgr; of the ferroelectric liquid crystal satisfy the condition &thgr;>&thgr;a>{fraction (&thgr;/2)}.
    Type: Grant
    Filed: September 13, 1995
    Date of Patent: September 24, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yukio Hanyu, Yutaka Inaba, Masanobu Asaoka, Osamu Taniguchi, Kenji Shinjo, Toshiharu Uchimi
  • Patent number: 6426783
    Abstract: A reflection mode, ferroelectric liquid crystal spatial light modulating system, includes a light reflecting type spatial light modulator. The spatial light modulator has a light reflecting surface cooperating with a layer of ferroelectric liquid crystal light modulating medium switchable between first and second states so as to act on light in different first and second ways, respectively. A switching arrangement switches the liquid crystal light modulating medium between the first and second states and an illumination arrangement produces a source of light. An optics arrangement is optically coupled the spatial light modulator and the illumination arrangement such that light is directed from the source of light into the spatial light modulator for reflection back out of the modulator and such that reflected light is directed from the spatial light modulator into a predetermined viewing area.
    Type: Grant
    Filed: September 24, 2001
    Date of Patent: July 30, 2002
    Assignee: Displaytech, Inc.
    Inventor: Charles M. Crandall
  • Patent number: 6420000
    Abstract: A liquid crystal device is constituted by a chiral smectic liquid crystal to form a plurality of pixels. The chiral smectic liquid crystal has a temperature-dependent tilt angle characteristic satisfying the following relationship: Ĥ10−Ĥ1≦4.0 degrees, wherein Ĥ10 denotes a tilt angle at a temperature which is 10° C. lower than an upper limit temperature of chiral smectic C phase and Ĥ1 denotes a tilt angle at a temperature which is 1° C. lower than the upper limit temperature.
    Type: Grant
    Filed: March 24, 2000
    Date of Patent: July 16, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinichi Nakamura, Masahiro Terada, Takeshi Togano, Yasushi Shimizu
  • Publication number: 20020089637
    Abstract: An optical device is provided. The optical device includes a plurality of high index layers. The optical device also includes a plurality of low index layers. The optical device is formed by creating alternating layers of the plurality of high layers and the plurality of low index layers, such that electricity and heat is allowed to be conducted through said optical device.
    Type: Application
    Filed: November 29, 2001
    Publication date: July 11, 2002
    Inventors: Desmond R. Lim, Kazumi Wada, Lionel C. Kimerling
  • Patent number: 6417828
    Abstract: An active matrix-type liquid crystal device is constituted by a pair of substrates, a chiral smectic liquid crystal composition disposed between the pair of substrates so as to form a plurality of pixels, and a plurality of active elements provided to the pixels, respectively, for driving the liquid crystal device in a matrix driving scheme. The chiral smectic liquid crystal composition may preferably comprise at least two specific fluorine-containing mesomorphic compounds and assume two stable states between which a threshold voltage for switching from one of the two stable states to the other stable state is different from a threshold voltage for switching from the other stable state to said one of the two stable states and liquid crystal molecules of the liquid crystal composition change their alignment states so as to provide a halftone state depending on a voltage applied to the chiral smectic liquid crystal.
    Type: Grant
    Filed: February 17, 2000
    Date of Patent: July 9, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Koichi Sato, Mineto Yagyu, Yukio Hanyu, Masahiro Terada, Koji Noguchi, Kouki Nukanobu
  • Patent number: 6395352
    Abstract: When a photopolymerization compound (molecular weight: not less than 300) having at least two ultraviolet light sensitive portions in its molecular structure is mixed with ferroelectric liquid crystal and an exposure to ultraviolet light is performed, a continuous structure is formed over almost whole length between two glass substrates, and a continuous twisted structure is formed between the glass substrates in the state of liquid crystal molecular orientation. Before the exposure to ultraviolet light, the photopolymerization compound does not exhibit satisfactory compatibility with the ferroelectric liquid crystal to be mixed, but exhibits phase separation in the mixed state. The ferroelectric liquid crystal has a bookshelf layer structure.
    Type: Grant
    Filed: September 28, 2000
    Date of Patent: May 28, 2002
    Assignee: Fujitsu Limited
    Inventors: Akihiro Mochizuki, Toshiaki Yoshihara, Hironori Shiroto, Tetsuya Makino, Yoshinori Kiyota
  • Patent number: 6377322
    Abstract: Each pair of gate lines GL are arranged aside a corresponding one of rows of pixel electrodes arranged in a matrix form, so as to sandwich pixel electrodes in the direction of columns, whereas each pair of TFTs are arranged to a sandwich corresponding one of the pixel electrodes, and each of data lines DL is arranged aside a corresponding one of columns of pixel electrodes. TFTs are connected to the pixel electrodes and to the gate lines GL so that the pixel electrodes of one row are selected when two of the gate lines GL sandwiching the pixel electrodes are selected. An end of a current path of each TFT is connected to the data line DL. When a pair of TFTs sandwiching one pixel electrode are simultaneously turned on, large current is supplied to the pixel electrode through the data line DL. Source electrode of TFT and source electrode of its proximate (adjacent) thin film transistor are formed by pattering the same metal layer, and share one current path connected to the data line DL.
    Type: Grant
    Filed: December 22, 1998
    Date of Patent: April 23, 2002
    Assignee: Casio Computer Co., Ltd.
    Inventors: Ikuhiro Yamaguchi, Hiromitsu Ishii
  • Publication number: 20020030776
    Abstract: A reflective cholesteric display that may be viewed under a wide range of ambient lighting conditions, ranging from complete darkness to bright sunlight. The display includes a chiral nematic liquid crystal material located between first and second substrates, an ambidextrous or bi-directional circular polarizer, a partial mirror, also referred to as a transflector, and a light source. The liquid crystal material includes focal conic and planar textures that are stable in the absence of an electric field. The ambidextrous circular polarizer is located adjacent to one of the substrates that constrain the liquid crystal material. The chiral nematic liquid crystal display may be operated in both a transmissive mode and a reflective mode.
    Type: Application
    Filed: September 24, 2001
    Publication date: March 14, 2002
    Applicant: Kent Displays Incorporated
    Inventors: Asad A. Khan, Michael E. Stefanov, Clive Catchpole
  • Patent number: 6351301
    Abstract: A liquid crystal display includes a liquid crystal layer. The liquid crystal layer includes a liquid crystal molecule. The liquid crystal molecule has a long axis, a short axis perpendicular to the long axis, a spontaneous polarization Ps along the short axis, a first permittivity &egr;// along the long molecular axis, and a second permittivity &egr;⊥ along the short axis. Here, the second permittivity &egr;⊥ is derived from polarizations other than the spontaneous polarization Ps. When a permittivity anisotropy &Dgr;&egr; defined as &Dgr;&egr;=&egr;//−&egr;⊥, it holds &Dgr;&egr;<0. An orientation of the liquid crystal molecule is determined by an effective electric field which is a sum of an exterior electric field applied to the liquid crystal layer and a depolarization field generated by the spontaneous polarization.
    Type: Grant
    Filed: July 7, 2000
    Date of Patent: February 26, 2002
    Assignee: NEC Corporation
    Inventor: Kenichi Takatori
  • Publication number: 20020018171
    Abstract: A liquid crystal device is constituted by a pair of substrates at least one of which is provided with a uniaxial alignment axis, and a chiral smectic liquid crystal disposed between the substrates to form a plurality of pixels arranged in rows and columns. Each pixel is provided with a switching element and an electrode for applying a voltage to the liquid crystal via the switching element. A matrix of signal lines comprising scanning signal lines and data signal lines is so arranged that each scanning signal line is disposed along a row of the pixels so as to connect a row of the switching elements provided to the row of the pixels and each data signal line is disposed along a column of the pixels so as to connect a column of the switching elements provided to the column of the pixels. The liquid crystal exhibits a phase transition series on temperature decrease of isotropic phase, cholesteric phase and chiral smectic C phase or of isotropic phase and chiral smectic C phase.
    Type: Application
    Filed: January 23, 2001
    Publication date: February 14, 2002
    Inventors: Yasufumi Asao, Takeshi Togano, Ryuichiro Isobe
  • Publication number: 20020015130
    Abstract: A chiral smectic liquid crystal device includes a chiral smectic liquid crystal exhibiting a phase transition series on temperature decrease of isotropic liquid phase (Iso), cholesteric phase (Ch) and chiral smectic C phase (SmC*) or of isotropic phase (Iso) and chiral smectic C phase (SmC*), and a pair of substrates each provided with an electrode for applying a voltage to the liquid crystal and a uniaxial alignment axis for aligning the liquid crystal. At least one of the substrates is provided with a polarizer and the pair of substrates are 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.
    Type: Application
    Filed: April 4, 2001
    Publication date: February 7, 2002
    Inventors: Hirohide Munakata, Naoya Nishida, Yasufumi Asao, Koji Noguchi, Ryuichiro Isobe
  • Patent number: 6344889
    Abstract: In a liquid crystal display in which a liquid crystal having spontaneous polarization is sandwiched between substrates, liquid crystal alignment which achieves a wide viewing angle and hardly causes alignment destruction is readily formed. A common electrode is formed by a pair of meshed comb electrodes, and rubbing alignment is performed in the logitudinal direction of teeth of these comb electrodes. When the liquid crystal material transits from a nematic phase or an isotropic phase to a chiral smectic C phase, a positive DC voltage, for example, is applied between a pixel electrode and one of the comb common electrodes, and a negative voltage is applied between a pixel electrode and the other comb common electrode. This readily accomplishes liquid crystal alignment in which smectic layers bend horizontally with respect to the substrate surface in space portions between the interdigitated teeth of the comb electrodes.
    Type: Grant
    Filed: March 16, 2000
    Date of Patent: February 5, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Rei Hasegawa, Takeshi Yamaguchi, Rieko Fukushima, Hajime Yamaguchi, Kohki Takatoh
  • Patent number: 6323850
    Abstract: A liquid crystal device of the active matrix-type having two-dimensionally arranged pixels along rows and columns is driven frame by frame. In each frame operation, a scanning selection period (TG) for each selected row is divided into a first period (t1) and a second period (t2). In t1 of a current frame (TF2), a reset pulse is applied to a pixel concerned, and the reset pulse is set to have an absolute value of voltage identical to and a polarity opposite to those of a writing pulse voltage applied to the pixel in the previous frame (TF1). Then, in t2 of the current frame (TF2), the pixel is supplied with a writing pulse depending on a prescribed display state of the pixel for the current frame. As a result, the reset period is shortened to favor a high-speed display and a higher resolution display.
    Type: Grant
    Filed: April 28, 1999
    Date of Patent: November 27, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazunori Katakura, Takashi Enomoto, Takao Takiguchi, Jun Iba, Seishi Miura
  • Publication number: 20010035932
    Abstract: A bright, and contrasty reflective display can be performed without using polarizer films, and display switching can be performed fast. A ferroelectric liquid crystal is sandwiched between substrates, and electrodes are formed face to face with each other in a direction parallel to the substrates. The ferroelectric liquid crystal, when no electric field is applied to it, goes into a planer state in which a helical axis becomes perpendicular to or almost perpendicular to the substrates, selectively reflecting light of specific wavelengths in a visible region. A driving circuit applies an electric field between the electrodes in a direction perpendicular to or almost perpendicular to the helical axis of the ferroelectric liquid crystal in the planer state.
    Type: Application
    Filed: April 26, 2001
    Publication date: November 1, 2001
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Teiichi Suzuki, Takehito Hikichi, Shigeru Yamamoto, Naoki Hiji
  • Patent number: 6310677
    Abstract: A liquid crystal device has a pair of oppositely disposed substrates and a liquid crystal having chiral smectic C phase disposed therebetween. The liquid crystal is placed in an alignment state in chiral smectic C phase with smectic molecular layers forming a chevron structure. Under no electric field application, the liquid crystal has an average molecular axis substantially in alignment with the uniaxial alignment axis and/or a bisector of a maximum angle formed between two extreme molecular axes established under electric field application, while under electric field application, the liquid crystal provides an effective tilt angle and a transmittance that continuously changes depending on an electric field applied thereto.
    Type: Grant
    Filed: February 25, 1999
    Date of Patent: October 30, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takeshi Togano, Masahiro Terada, Shosei Mori, Yasufumi Asao, Takashi Moriyama
  • Patent number: 6310664
    Abstract: A reflection mode, ferroelectric liquid crystal spatial light modulating system, includes a light reflecting type spatial light modulator. The spatial light modulator has a light reflecting surface cooperating with a layer of ferroelectric liquid crystal light modulating medium switchable between first and second states so as to act on light in different first and second ways, respectively. A switching arrangement switches the liquid crystal light modulating medium between the first and second states and an illumination arrangement produces a source of light. An optics arrangement is optically coupled the spatial light modulator and the illumination arrangement such that light is directed from the source of light into the spatial light modulator for reflection back out of the modulator and such that reflected light is directed from the spatial light modulator into a predetermined viewing area.
    Type: Grant
    Filed: September 13, 2000
    Date of Patent: October 30, 2001
    Assignee: Displaytech, Inc.
    Inventor: Charles M. Crandall
  • Publication number: 20010030731
    Abstract: The present invention provides a monostable ferroelectric liquid crystal display apparatus includes a pair of substrates, each subjected to uniaxial orientation processing and arranged so that their orientation processing directions are approximately parallel to each other; and a ferroelectric liquid crystal material having the chiral smectic C phase filled between the substrates, the liquid crystal material being such that the projection component of the cone drawn by a liquid crystal molecule of the ferroelectric liquid crystal material projected onto the substrate and the projection component of the liquid crystal molecule itself projected onto the substrate in the molecule axis direction are respectively identical to the orientation processing direction of the substrates, which state is the initial state of the monostable configuration, wherein the ferroelectric liquid crystal contains a compound having a phenyl pyrimidine skeleton having one end connected to an alkoxyl chain and the other end connected t
    Type: Application
    Filed: February 15, 2001
    Publication date: October 18, 2001
    Inventors: Teiichiro Nishimura, Makoto Jisaki, Tadaaki Isozaki, Eiji Okabe, Ryushi Shundo, Hideo Saito
  • 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
  • Publication number: 20010017676
    Abstract: A polarizing element provided with a layer including liquid crystals and a polarizer having a transmission axis. The polarizing element of the present invention is structured such that liquid crystal molecules in the aforementioned liquid crystal layer have a chiral smectic texture of a helical configuration with respect to a axis, the axis is not along a direction normal to a surface of the liquid crystal layer (a z-direction), and a direction of an orthogonal projection of the axis onto the surface of the liquid crystal layer is substantially at 90° to the polarizers transmission axis.
    Type: Application
    Filed: January 19, 2001
    Publication date: August 30, 2001
    Inventors: Kohei Arakawa, Mitsuyoshi Ichihashi
  • Publication number: 20010015788
    Abstract: A liquid crystal display of the present invention includes first and second substrates. The first substrate has a surface supporting thereon a plurality of parallel first electrodes. The second substrate has a first surface and second surface opposed to the first surface. The first surface supports thereon a plurality of parallel second electrodes. The second substrate is positioned so that the first surface opposes the surface of the first substrate to define a gap therebetween and the first and second electrodes cross with each other. A memory type liquid crystal is filled in the gap. A plurality of first and second terminals are positioned on the second surface and electrically connected with the first and second electrodes, respectively, so that the first and second terminals are capable of being connected with an external device.
    Type: Application
    Filed: December 26, 2000
    Publication date: August 23, 2001
    Inventors: Makiko Mandai, Nobuyuki Taniguchi, Masahide Ueda, Yutaka Tsurumoto, Koichi Kohriyana, Masashi Nishikado
  • Publication number: 20010005259
    Abstract: A liquid crystal display device comprises a pair of substrates on whose opposing surfaces electrodes are formed; and a liquid crystal provided between the substrates and having spontaneous polarization and a physical property such that when a positive or negative saturation voltage whose absolute value is sufficiently large is applied between the electrodes, liquid crystal molecules are aligned in a first direction or a second direction, and when an arbitrary voltage lying between the positive saturation voltage and the negative saturation voltage is applied between the electrodes, a director is aligned in an arbitrary direction which corresponds to the applied voltage and which lies in a cone angle formed by the first direction and the second direction.
    Type: Application
    Filed: December 27, 2000
    Publication date: June 28, 2001
    Inventor: Jun Ogura
  • Patent number: 6246452
    Abstract: A ferroelectric chiral smectic liquid crystal mixture comprising at least one compound of the formula (I): wherein R11 and R12 represent, independently each other, a C1-C20 alkyl, alkoxy or alkoxyalkyl group which may be substituted by at least one halogen atom and may have an unsaturated bond; A11, A12 and A13 represent, independently each other, a phenylene group which may be substituted by a fluorine atom, or the like; * indicates an asymmetric carbon atom; Z is a hydrogen atom or a fluorine atom; n is an integer of 0 to 10; r, s, t and u are each 0 or 1, provided that when u is 1, the compound (I) is a trans-olefin, and at least one compound of the formula (II): wherein R21 is a saturated or unsaturated C3-C20 alkyl group or a saturated or unsaturated C3-C20 alkoxyalkyl group; A21, A22 and A23 represent, independently each other, a phenylene group which may be substituted by a fluorine atom or the like; X2 is —C≡C— or the like; Z is a hydrogen atom or
    Type: Grant
    Filed: October 19, 1995
    Date of Patent: June 12, 2001
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Chizu Sekine, Kyoko Yamamoto, Koichi Fujisawa, Yukari Fujimoto, Tsutomu Matsumoto, Masayoshi Minai
  • Patent number: 6215543
    Abstract: In order to reduce the effects of impact on liquid crystal devices a polymer network is introduced into ferroelectric liquid crystal cells. A liquid crystal device comprises two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, characterised in that the liquid crystal material contains a small amount of monomer. The liquid crystal material may also contain a photoinitiator. The monomer material may be cured to produce the polymer networks the curing many be carried out in the presence of an electric or magnetic field. Further, the monomer may be cured in an isotropic or liquid crystal phase.
    Type: Grant
    Filed: March 1, 2000
    Date of Patent: April 10, 2001
    Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventors: Ian Robert Mason, Damien Gerard McDonnell, John Clifford Jones, Guy Peter Bryan-Brown
  • Patent number: 6208403
    Abstract: An antiferroelectric liquid crystal display device includes: an active matrix type LC cell and an antiferroelectric liquid crystal sealed in the cell. Liquid crystal molecules aligned to one of a first aligning direction and a second aligning direction are aligned in the other aligning direction in accordance with an applied voltage, thus forming a plurality of regions of different alignment states in a range shorter than a wavelength of light in a visible light band, and directions of said directors are changed in accordance with a ratio of regions in a first alignment state to regions in a second alignment state. The liquid crystal molecules may behave along a predetermined cone by a phase transition precursor in accordance with an applied voltage. The liquid crystal molecules may behave so as to be inclined in a direction perpendicular to an electric field, in accordance with an applied voltage.
    Type: Grant
    Filed: April 24, 2000
    Date of Patent: March 27, 2001
    Assignee: Casio Computer Co., Ltd.
    Inventors: Tomio Tanaka, Tetsushi Yoshida, Jun Ogura, Satoru Shimoda
  • 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: 6184967
    Abstract: The invention relates to an essentially pressure-insensitive liquid crystal cell. Electrode-equipped (5, 6) plates (1, 2) are arranged at a predetermined distance from each other and define a liquid crystal layer of a thickness d. At least a first (1) of the plates is transparent and has a thickness b not exceeding 1 mm, and a modulus of elasticity E. Spacers (11) fixed in the cavity and having a height h are distributed with a spacing L and have substantially the same modulus of elasticity E as said first plate. The spacers (11) have a width not exceeding 50 &mgr;m, at least in one direction. The degree of the surface coverage s by the supporting areas of the spacers (11) on said first plate (1) exceeds or is equal to a minimum value which is dependent on the type of liquid crystal.
    Type: Grant
    Filed: November 25, 1997
    Date of Patent: February 6, 2001
    Assignee: EMT AG
    Inventors: Sven T. Lagerwall, Anatoli A. Muravski, Sergei Ye Yakovenko, Viktor A. Konovalov, Anatoli A. Minko, Valeri P. Tsarev
  • Patent number: 6181407
    Abstract: An electro-optic material that is characterized by short reaction times when working with a low drive voltage. For that, the electro-optic material has a lamellar liquid crystal (10), which contains one or more components and into which chiral molecules (20), whose longitudinal axes (m) are longer than the longitudinal axes of the molecules (10) forming the lamellar liquid crystal, are introduced at a predefined concentration, so that the longitudinal axes (m) of the chiral molecules (20) are tilted, without an external electric field, statistically by a predefined angle (&thgr;m) toward the normal (z) of the layer of the lamellar liquid crystal (10).
    Type: Grant
    Filed: June 23, 1997
    Date of Patent: January 30, 2001
    Assignee: Deutsche Telekom AG
    Inventors: Wolfgang Dultz, Leonid Beresnev, Ashok Bizadar, Wolfgang Haase
  • Patent number: 6177968
    Abstract: An optical modulation device is constituted by a first substrate provided with a plurality of first electrodes each comprising a plurality of portions electrically independent of each other, a second substrate disposed opposite to the first substrate and provided with a plurality of second electrodes each confronting a corresponding first electrode, and an optical modulation substance disposed between the first and second substrates so as to form a plurality of pixels each having a particular electrode structure. In the electrode structure, the optical modulation substance is sandwiched between each second electrode and said portions of said corresponding first electrode so as to form a series circuit providing a plurality of capacitance, thus reducing the capacitance for each pixel to improve a switching characteristic while minimizing a defective portion due to a short-circuit between the confronting electrodes.
    Type: Grant
    Filed: August 28, 1998
    Date of Patent: January 23, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinjiro Okada, Hirohide Munakata, Takashi Enomoto, Yutaka Inaba, Takahiro Hachisu
  • Patent number: RE37509
    Abstract: A method, device, and material for providing a fast switching liquid crystal display employs the ferro electric effect of chiral smectic liquid crystal material. To provide a uniform appearance the liquid crystal material is arranged to have a long cholesteric pitch at a temperature close to a smectic/cholesteric phase transistion temperature. This long cholesteric pitch allows liquid crystal molecules to cool from the cholesteric to smectic phase with a uniform alignment. The smectic material is contained in a cell between wells (2, 3) bearing electrodes (5, 6) and surface treated to provide homogeneous alignment of liquid crystal material (7).
    Type: Grant
    Filed: January 10, 1995
    Date of Patent: January 15, 2002
    Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britian and Northern Ireland
    Inventors: Madeline J. Bradshaw, Edward P. Raynes