Within Smectic Phase Patents (Class 349/171)
  • Patent number: 11647169
    Abstract: Provided is a reflective screen and a projection image display system in which a transmittance of light can be selectively changed, a transmittance in a transparent state is sufficiently high, a voltage does not need to be applied constantly, and a voltage is applied to decrease a transmittance of light in a case where the reflective screen is irradiated with video light.
    Type: Grant
    Filed: September 12, 2022
    Date of Patent: May 9, 2023
    Assignee: FUJIFILM Corporation
    Inventors: Shuntaro Ibuki, Naoya Nishimura
  • Patent number: 11390091
    Abstract: Embodiments of the present invention are directed to systems and methods for writing on electronic paper (“e-paper”) and display platforms implemented with e-paper. In one aspect, a system for writing information to electronic paper includes a writing module and an erasing unit connected to the writing module. The erasing unit is configured to erase information stored in the electronic paper. The system also includes a writing unit connected to the writing module and is configured to write information to the electronic paper. Information is written to the electronic paper by orienting the writing module so that the electronic paper passes the erasing unit prior to passing the writing unit.
    Type: Grant
    Filed: January 15, 2020
    Date of Patent: July 19, 2022
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Omer Gila, Napoleon J. Leoni, Steven Rosenberg, Henryk Birecki
  • Patent number: 11269131
    Abstract: An optical device is provided. The optical device includes a first optical element configured to output an elliptically polarized light having one or more predetermined polarization ellipse parameters. The optical device also includes a second optical element including a birefringent material with a chirality, and configured to receive the elliptically polarized light from the first optical element and reflect the elliptically polarized light as a circularly polarized light.
    Type: Grant
    Filed: March 16, 2020
    Date of Patent: March 8, 2022
    Assignee: FACEBOOK TECHNOLOGIES, LLC
    Inventors: Fenglin Peng, Junren Wang, Yuge Huang, Lu Lu, Yusufu Njoni Bamaxam Sulai, Ying Geng, Jacques Gollier, Barry David Silverstein, Yu-Jen Wang, Yun-Han Lee
  • Patent number: 10538111
    Abstract: Embodiments of the present invention are directed to systems and methods for writing on electronic paper (“e-paper”) and display platforms implemented with e-paper. In one aspect, a system for writing information to electronic paper includes a writing module and an erasing unit connected to the writing module. The erasing unit is configured to erase information stored in the electronic paper. The system also includes a writing unit connected to the writing module and is configured to write information to the electronic paper. Information is written to the electronic paper by orienting the writing module so that the electronic paper passes the erasing unit prior to passing the writing unit.
    Type: Grant
    Filed: July 31, 2017
    Date of Patent: January 21, 2020
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Omer Gila, Napoleon J. Leoni, Steven Rosenberg, Henryk Birecki
  • Patent number: 10495798
    Abstract: Disclosed herein are techniques for displaying images on multiple image planes in a near-eye display system. A switchable optical device includes a first polarizer configurable to polarize incident light into light of a first circular polarization state, and a second polarizer configurable to transmit light of a second circular polarization state and reflect light of the first circular polarization state into light of the first circular polarization state. The switchable optical device also includes a partial reflector positioned between the first polarizer and the second polarizer. The partial reflector is configured to transmit light from the first polarizer and reflect light from the second polarizer, where the reflected light and the light from the second polarizer have different polarization states. At least one of the first polarizer or the second polarizer includes a cholesteric liquid crystal (CLC) circular polarizer that is switchable by a voltage signal.
    Type: Grant
    Filed: August 7, 2018
    Date of Patent: December 3, 2019
    Assignee: Facebook Technologies, LLC
    Inventors: Fenglin Peng, Ying Geng, Yusufu Njoni Bamaxam Sulai, Mengfei Wang, Lu Lu, Jacques Gollier
  • Patent number: 9575366
    Abstract: A liquid crystal cell structure is provided. The liquid crystal cell structure includes: two polarizers; and a liquid crystal diffractive light modulating cell placed between the two polarizers. The cell includes: two transparent substrates treated by photoalignment; and a ferroelectric liquid crystal layer disposed between the two transparent substrates with current conducting layers, the ferroelectric liquid crystal layer comprising ferroelectric liquid crystals. The two transparent substrates treated by photoalignment are configured to provide multiple alignment domains in the ferroelectric liquid crystals with a planar surface orientation. Adjacent domains of the multiple alignment domains are oriented at an angle with respect to each other.
    Type: Grant
    Filed: December 21, 2012
    Date of Patent: February 21, 2017
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Abhishek Kumar Srivastava, Wei Hu, Yanqing Lu, Fei Xu, Vladimir Grigorievich Chigrinov, Hoi Sing Kwok
  • Patent number: 8570481
    Abstract: A liquid crystal material in which liquid crystal molecules have uniform alignment state is provided. A liquid crystal layer containing a liquid crystal material is included between a TFT array substrate and an opposed substrate. The liquid crystal material has a phase system continuously showing an isotropic phase, a nematic phase, and a smectic ‘A’ phase in this order as temperature changes from higher state to lower state and shows electroclinic effect in the smectic ‘A’ phase. As the liquid crystal material is heated (temperature is increased), the nematic phase is shown after the smectic ‘A’ phase without other phase in between, and the isotropic phase is shown after the nematic phase without other phase in between. Since the alignment state of the liquid crystal molecules becomes uniform, the transmittance is precisely controlled.
    Type: Grant
    Filed: October 28, 2010
    Date of Patent: October 29, 2013
    Assignee: Sony Corporation
    Inventors: Hidehiko Takanashi, Ken Kobayashi, Rika Kotake, Aya Shuto
  • Patent number: 8330890
    Abstract: A plurality of display elements each includes two signal lines: S1 and S2. An electrode 4, which is one of the electrodes constituting an element capacitor Cp, is connected to the signal line S1 via a switching element TFT1, while the other electrode 5 is connected to the signal line S2 via a switching element S2. The gate electrodes of the switching elements TFT1 and TFT2 are connected to a single common scanning line G. With this structure the drive voltage applied to the element capacitor can be increased even when a TFT has a limited withstand pressure.
    Type: Grant
    Filed: June 15, 2010
    Date of Patent: December 11, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Koichi Miyachi, Kiyoshi Ogishima, Akihito Jinda
  • Patent number: 8259243
    Abstract: A controllable device for phase modulation of coherent light with modulator cells comprising liquid crystal molecules is provided which realizes a large number of phase steps per modulator cell and whose switching delay is shorter than 1 ms. The device can include a spatial light modulator with a modulator matrix having regularly arranged controllable LC modulator cells, a light source which illuminates the modulator matrix, and control means for controlling the phase modulation in the LC modulator cells. The modulator matrix can be configured to comprise a controllable ?/2 plate disposed between two non-controllable ?/4 plates; the controllable LC modulator cells can be PSS liquid crystal; each LC modulator cell is controllable locally with a positive or negative voltage value, depending on the actual phase values to be written; and the control means generate a globally constant phase offset for the phase values to be written in every other frame.
    Type: Grant
    Filed: May 15, 2009
    Date of Patent: September 4, 2012
    Assignee: Seereal Technologies S.A.
    Inventor: Norbert Leister
  • Patent number: 8203680
    Abstract: A liquid crystal display includes a first alignment film having a first alignment direction, a second alignment film having a second alignment direction, and a liquid crystal layer having liquid crystal molecules between the first and second alignment films. The liquid crystal layer is doped with a chiral material that tends to induce a first twist in directors of the liquid crystal molecules when an electric field is applied to the liquid crystal layer. The first and second alignment films have orientations that tends to induce a second twist in the directors when an electric field is applied to the liquid crystal layer, in which the direction of the first twist is different from the direction of the second twist.
    Type: Grant
    Filed: May 18, 2011
    Date of Patent: June 19, 2012
    Assignee: Chimei Innolux Corporation
    Inventors: Ju-Hyun Lee, Shin-Tson Wu, Wang-Yang Li, Chung-Kuang Wei
  • Patent number: 8045115
    Abstract: A liquid crystal display includes a first alignment film having a first alignment direction, a second alignment film having a second alignment direction, and a liquid crystal layer having liquid crystal molecules between the first and second alignment films. The liquid crystal layer is doped with a chiral material that tends to induce a first twist in directors of the liquid crystal molecules when an electric field is applied to the liquid crystal layer. The first and second alignment films have orientations that tends to induce a second twist in the directors when an electric field is applied to the liquid crystal layer, in which the direction of the first twist is different from the direction of the second twist.
    Type: Grant
    Filed: December 22, 2006
    Date of Patent: October 25, 2011
    Assignees: Chimei Innolux Corporation, University of Central Florida Research Foundation, Inc,
    Inventors: Ju-Hyun Lee, Shin-Tson Wu, Wang-Yang Li, Chung-Kuang Wei
  • Patent number: 8026992
    Abstract: A plurality of display elements each includes two signal lines: S1 and S2. An electrode 4, which is one of the electrodes constituting an element capacitor Cp, is connected to the signal line S1 via a switching element TFT1, while the other electrode 5 is connected to the signal line S2 via a switching element S2. The gate electrodes of the switching elements TFT1 and TFT2 are connected to a single common scanning line G. With this structure the drive voltage applied to the element capacitor can be increased even when a TFT has a limited withstand pressure.
    Type: Grant
    Filed: October 13, 2009
    Date of Patent: September 27, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Koichi Miyachi, Kiyoshi Ogishima, Akihito Jinda
  • Patent number: 7903228
    Abstract: A liquid crystal device comprises ferroelectric particles suspended in a liquid crystal material. A method for fabricating a light-modulating device is also disclosed. The method comprises the steps of providing a pair of substrates with a cell gap therebetween, wherein electrodes are disposed on the facing surfaces of the substrates, and permanently disposing a suspension of ferroelectric particles in a liquid crystal material into said cell gap. A method of generating an image comprises providing a pair of substrates with a cell gap therebetween, providing transparent electrodes on each of said substrates adjacent to the cell gap, permanently disposing a suspension of ferroelectric particles in a liquid crystal material within the cell gap, and applying an electric field across the electrodes.
    Type: Grant
    Filed: January 10, 2003
    Date of Patent: March 8, 2011
    Assignee: Kent State University
    Inventors: Yurii Reznikov, Anatoliy Glushchenko, Victor Reshetnyak, John West
  • Publication number: 20100283925
    Abstract: A liquid crystal formulation is described. The liquid crystal formulation comprises a first oligosiloxane-modified nano-phase segregating liquid crystalline material; and at least one additional material selected from a second oligosiloxane-modified nano-phase segregating liquid crystalline material, non-liquid crystalline oligosiloxane-modified materials, organic liquid crystalline materials, or non-liquid crystalline materials, wherein the liquid crystal formulation has an I?SmA*?SmC* phase transition, with a SmC* temperature range from about 15° C. to about 35° C., a tilt angle of about 22.5°±6° or about 45°±6°, a spontaneous polarization of less than about 50 nC/cm2., and a rotational viscosity of less than about 600 cP. Devices containing liquid crystal formulations are also described.
    Type: Application
    Filed: October 26, 2007
    Publication date: November 11, 2010
    Applicants: DOW CORNING CORPORATION, CAMBRIDGE ENTERPRISE LTD.
    Inventors: Jonathan Paul Hannington, Terry Victor Clapp, Fumito Nishida, Russell Keith King, Omar Farooq, Martin Grasmann, William Alden Crossland, Harry James Coles, Anthony Bernard Davey, Huan Xu, Oliver Hadeler, Mykhaylo Pivnenko
  • Patent number: 7768589
    Abstract: A plurality of display elements each includes two signal lines: S1 and S2. An electrode 4, which is one of the electrodes constituting an element capacitor Cp, is connected to the signal line S1 via a switching element TFT1, while the other electrode 5 is connected to the signal line S2 via a switching element S2. The gate electrodes of the switching elements TFT1 and TFT2 are connected to a single common scanning line G. With this structure the drive voltage applied to the element capacitor can be increased even when a TFT has a limited withstand pressure.
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: August 3, 2010
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Koichi Miyachi, Kiyoshi Ogishima, Akihito Jinda
  • Patent number: 7758773
    Abstract: This disclosure outlines a new method of modifying the properties of existing liquid crystals by doping them with ferroelectric micro- and nanoparticles. We show that this approach, in contrast to the traditional time consuming and expensive chemical synthetic methods, enriches and enhances the electro-optical performance of many liquid crystal materials. We demonstrate that by changing the concentration and type of ferroelectric particles the physical properties of the nematic, smectic, and cholesteric liquid crystal materials can be changed, including the dielectric constants, the birefringence, the phase transition temperatures, and even the order parameter. We also demonstrate the performance of these new materials in various devices, including displays, light modulators, and beam steering devices.
    Type: Grant
    Filed: March 14, 2007
    Date of Patent: July 20, 2010
    Assignee: Kent State University
    Inventors: John L. West, Chae Il Cheon, Anatoliy V. Glushchenko, Yuriy Reznikov, Fenghua Li
  • Patent number: 7733557
    Abstract: A holographic data storage system that includes a write head that includes a pixellated spatial light modulator and a separate or integral phase mask that varies the phase depending on the location in the phase mask that light passes through. The phase variation can be changed over time in a random, pseudo-random, or predetermined fashion. The spatial light modulator and phase mask can be implemented in a liquid crystal SLM (nematic, ferroelectric, or other), in a DMD SLM, in a magneto-optical SLM, or in any other suitable manner.
    Type: Grant
    Filed: April 24, 2007
    Date of Patent: June 8, 2010
    Assignee: Micron Technology, Inc.
    Inventors: Mark A. Handschy, Michael J. O'Callaghan
  • Patent number: 7612862
    Abstract: An object of the invention is to provide a liquid crystal device that uses a smectic liquid crystal and that can produce a uniform display. The liquid crystal device includes a pair of substrates, a smectic liquid crystal provided between the pair of substrates, an injection hole for injecting therethrough the smectic liquid crystal into a gap formed between the pair of substrates, a plurality of scanning electrodes arranged at right angles to the direction of injection of the smectic liquid crystal between the pair of substrates, an alignment film deposited over the plurality of scanning electrodes, and voltage applying means for applying a voltage to the plurality of scanning electrodes in sequence proceeding from a side nearest to the injection hole toward a side farthest therefrom.
    Type: Grant
    Filed: March 20, 2008
    Date of Patent: November 3, 2009
    Assignee: Citizen Holdings Co., Ltd.
    Inventor: Kenji Noguchi
  • Patent number: 7564508
    Abstract: A light path shift device is disclosed that is able to divide an effective region of a light path and drive the divided regions independently. The light path shift device includes a liquid crystal layer held between at least two opposite transparent substrates, the liquid crystal layer being homeotropically aligned and being able to form a chiral smectic C phase; and plural electrodes for applying an electric field in the liquid crystal layer in a horizontal direction. An effective region of the liquid crystal layer through which a light path passes is divided into plural sub-regions, plural light path shift elements with the electrodes formed thereon are stacked only at positions corresponding to the sub-regions, and are arranged so that boundary lines of the sub-regions are in agreement when being viewed along the direction of light propagation.
    Type: Grant
    Filed: March 14, 2006
    Date of Patent: July 21, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroyuki Sugimoto, Toshiaki Tokita, Kazuhiro Fujita, Toshiharu Murai, Yasuyuki Takiguchi, Atsushi Takaura, Kazuya Miyagaki, Takanobu Osaka
  • Patent number: 7550094
    Abstract: A liquid crystal device including a first electrode substrate, a second electrode substrate and a liquid crystal layer is provided. The liquid crystal layer is disposed between the first electrode substrate and the second electrode substrate. The liquid crystal layer comprises liquid crystal molecules and particles. The liquid crystal molecules are vertically aligned when the applied voltage between the first electrode substrate and the second electrode substrate is less than a threshold voltage. The arrangement of the liquid crystal molecules is changed so as to produce optical changes in the liquid crystal device when the applied voltage between the first electrode substrate and the second electrode substrate is not less than the threshold voltage.
    Type: Grant
    Filed: July 31, 2007
    Date of Patent: June 23, 2009
    Assignee: Industrial Technology Research Institute
    Inventors: Shie-Chang Jeng, Hsing-Lung Wang, Chi-Chang Liao
  • Publication number: 20090073372
    Abstract: A liquid crystal display device capable of improving response characteristics while maintaining display characteristics, and a liquid crystal display using such a liquid crystal display device are provided. Provided is the liquid crystal display device including a pair of substrates facing each other, and electrodes and a liquid crystal layer provided between the pair of substrates, where the liquid crystal layer is composed of liquid crystal material including a liquid crystal molecule showing a nematic liquid crystal phase and a molecule providing tilt to the liquid crystal molecule.
    Type: Application
    Filed: March 20, 2008
    Publication date: March 19, 2009
    Applicant: Sony Corporation
    Inventor: Seiji Shibahara
  • Patent number: 7489383
    Abstract: An optical axis deflecting element is provided with a pair of transparent substrates, a liquid crystal layer disposed between substrate surfaces of the pair of transparent substrates and having a chiral smectic C-phase forming a homeotropic orientation, and a plurality of electrode pairs each defining one of a plurality of divided regions into which an effective region of the liquid crystal layer is divided, wherein an electric field is independently applicable to each divided region defined by a corresponding electrode pair in a direction parallel to the substrate surfaces.
    Type: Grant
    Filed: April 24, 2006
    Date of Patent: February 10, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroyuki Sugimoto, Yumi Matsuki, Yukiko Hirano, Kenji Namie, Toshiaki Tokita, Takanobu Osaka, Koh Fujimura
  • Patent number: 7345733
    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: Grant
    Filed: April 11, 2006
    Date of Patent: March 18, 2008
    Assignee: Ricoh Comapny, Ltd.
    Inventors: Hiroyuki Sugimoto, Toshiaki Tokita, Yumi Matsuki, Shigeaki Nimura, Masanori Kobayashi, Yasuyuki Takiguchi, Kenji Kameyama, Ikuo Katoh
  • Patent number: 7342632
    Abstract: A display element of the present invention includes: a pair of substrates at least one of which is transparent; a medium layer, made of a medium sandwiched between the substrates 1 and 2, whose magnitude of an optical anisotropy is changed by applying an electric field; and at least a pair of electrodes applying to the medium layer an electric field which is substantially parallel to the substrates. The electrodes are provided above the substrate via insulating layers each of which is formed in a convex shape. Therefore, a maximal electric field region generated by the electrodes is separated from interfaces of the substrates.
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: March 11, 2008
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Koichi Miyachi, Seiji Shibahara, Iichiro Inoue, Akihito Jinda, Takako Koide, Kiyoshi Ogishima
  • Patent number: 7215400
    Abstract: An in-plane switching mode liquid crystal display device includes a first substrate, a second substrate, ferroelectric liquid crystal layers between the first and second substrates disposed substantially at respective surfaces of the first and second substrates, the ferroelectric liquid crystal layers arranged by an exposure to one of an amphiphobic medium and an amphiphilic medium, a nematic liquid crystal layer between the ferroelectric liquid crystal layer of the first substrate and the ferroelectric liquid crystal layer of the second substrate, and electrodes disposed on surfaces of each of the first and second substrates to vertically apply an electric field to the ferroelectric liquid crystal layers and to the nematic liquid crystal layer.
    Type: Grant
    Filed: October 14, 2004
    Date of Patent: May 8, 2007
    Assignee: LG.Philips LCD Co., Ltd
    Inventor: Su Seok Choi
  • Patent number: 7212269
    Abstract: A ferroelectric liquid crystal display having alignment films with different surface polarities. The alignment films induce an internal electric field through the liquid crystal. Because of the induced internal electric field, initial liquid crystal alignment, and subsequent liquid crystal alignments, can be performed without an externally applied electric field.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: May 1, 2007
    Assignee: LG.Philips LCD Co., Ltd.
    Inventors: Suk Won Choi, Su Seok Choi
  • Patent number: 7033653
    Abstract: The invention relates to a birefringent marking comprising a liquid crystal material. The invention further relates to method of providing such a birefringent marking and to the use of the birefringent marking for decorative or security applications.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: April 25, 2006
    Assignee: Merck Patent GmbH
    Inventors: Matthias Kuntz, Robert Hammond-Smith, Rodney Riddle, John Patrick, Donald Graham
  • 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: 6927825
    Abstract: When a transition voltage, which is higher than a display voltage for image display, is applied to liquid crystal, the liquid crystal can transition to a bend alignment. Therefore, by applying a transition voltage to liquid crystal prior to image display period only for a transition time which depends on a transition voltage so as to cause a bend transition in the liquid crystal, an OCB mode LCD with a high speed response can be obtained. An interval d between pixel regions is set to be less than, for example, a transition distance of 5 ?m, so that a bend transition expands over inter-pixel regions to thereby achieve a bend transition all over the display region. In an active matrix type LCD, a electrical field is caused to be generated between a common electrode and data lines or gate lines disposed between pixel electrodes due to application of a transition voltage to the common electrode, thereby obtaining a bent transition over the entire surface of the display screen.
    Type: Grant
    Filed: May 11, 2000
    Date of Patent: August 9, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Norio Koma, Tatsuo Uchida
  • Patent number: 6911238
    Abstract: A novel polarization selective membrane is disclosed. The membrane comprises a liquid crystal molecule having a helical structure and selectively transmits specific polarized light and selectively reflects the other polarized light. The helical axis of the helical structure is practically oriented in the normal direction of the membrane plane, and the angle between the helical axis of the helical structure and the long axis of the liquid crystal molecules is from 5° to 85°.
    Type: Grant
    Filed: February 27, 2003
    Date of Patent: June 28, 2005
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Atsuhiro Okawa, Michio Nagai, Masaki Noro
  • Patent number: 6888610
    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: Grant
    Filed: January 16, 2003
    Date of Patent: May 3, 2005
    Assignee: Fujitsu Limited
    Inventors: Toshiaki Yoshihara, Hironori Shiroto, Tetsuya Makino, Keiichi Betsui
  • Publication number: 20030218708
    Abstract: A wavelength-selective reflection film comprises at least one layer. In the layer, liquid crystal molecules are aligned in a chiral smectic phase. The chiral smectic phase has a helical pitch and an average refractive index. The product of the helical pitch and the average refractive index is in the range of 213 to 450 rm. The layer selectively reflects light in a particular wavelength range, and selectively transmits light in another wavelength range.
    Type: Application
    Filed: May 21, 2003
    Publication date: November 27, 2003
    Applicant: FUJI PHOTO FILM CO., LTD.
    Inventor: Mitsuyoshi Ichihashi
  • Patent number: 6642990
    Abstract: A liquid crystal display element including a first electrode substrate having a first transparent substrate, a first electrode formed on the first substrate, and a first alignment layer formed on the first substrate. The liquid crystal display element further includes a second electrode substrate having a second transparent substrate, a second electrode formed on the second substrate, and a second alignment layer formed on the second substrate. The liquid crystal display element also has a light modulating layer of a smectic liquid crystal material which is sandwiched between the first and second electrode substrates and which has a thresholdless voltage-transmittance characteristic and a spontaneous polarization of 120 nC/cm2 or less. Further, the polarity force component of the surface free energy of each of the first and second alignment layers is 13 dyn/cm or less.
    Type: Grant
    Filed: September 10, 2001
    Date of Patent: November 4, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Rieko Fukushima, Tatsuo Saishu, Rei Hasegawa, Hajime Yamaguchi, Kohki Takatoh
  • Patent number: 6614501
    Abstract: An electroconductive device functioning as, e.g., an organic EL device, is formed of a pair of oppositely disposed electrodes and organic compound layers disposed between the electrodes so as to be supplied with a voltage applied between the electrodes. The organic compound layers include at least one layer of a liquid crystalline organic compound in a supercooled liquid crystal phase As a result, the electroconductive device can exhibit an improved performance over a broad temperature range due to the presence of the organic compound layer in a liquid crystal phase.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: September 2, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takashi Moriyama, Shinjiro Okada, Akira Tsuboyama, Takao Takiguchi
  • Publication number: 20030160211
    Abstract: An electric charge transport method with a high current density and excellent charge transporting capability is provided. Specifically, the charge transport method includes applying a voltage to a liquid crystalline compound in a smectic B liquid crystal phase, which liquid crystalline compound exhibits a smectic B phase as a liquid crystal phase, or applying a voltage to a liquid crystalline compound in a solid state formed as a result of phase transition from a smectic phase, which liquid crystalline compound exhibits the smectic phase as a liquid crystal phase.
    Type: Application
    Filed: December 4, 2002
    Publication date: August 28, 2003
    Inventor: Yuichiro Haramoto
  • 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: 6537624
    Abstract: A light-diffusible liquid crystalline film having a fixed cholesteric or chiral smectic C orientation in which the helical axis direction is not uniformly parallel to the film thickness direction, as well as a liquid crystalline film having a fixed cholesteric or chiral smectic C orientation in which the helical axis direction is not uniformly parallel to the film thickness direction nor is the helix pitch uniformly equal in the film thickness direction, are provided.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: March 25, 2003
    Assignee: Nippon Mitsubishi Oil Corporation
    Inventors: Shinichiro Suzuki, Suzushi Nishimura, Shinichi Komatsu
  • Patent number: 6532051
    Abstract: The present invention deals with liquid crystal displays where the incident light and reflected light going through the display are not specularly related. The incident light can be at a range of angles to the display while the reflected light, i.e. the viewing direction is at or nearly normal to the display. For such nonspecular liquid crystal displays, the polarizer angles, the input/output directors of the liquid crystal cell, and the liquid crystal cell retardation have to be specially optimized to obtain the best viewing effects. Conventional liquid crystal display modes do not work optimally in this nonspecular situation. We also disclose the new image-mode and shadow-mode nonspecular liquid crystal displays. Such displays have very bright background and are free from viewing glare common in most liquid crystal displays. The present invention applies to all twist angles, e.g. the 90° TN, the 120° and 150° HTN, the 180°, 240° and 270° STN displays.
    Type: Grant
    Filed: August 11, 2000
    Date of Patent: March 11, 2003
    Assignee: Varintelligent (BVI) Limited
    Inventors: Colin T. Yeoh, Hoi Sing Kwok, York Liao
  • Patent number: 6522382
    Abstract: A liquid crystal cell includes a liquid crystal layer between upper and lower substrates. A series of insulating ridges forming a monograting structure overlay a first electrode overlaying the lower substrate. The ridges carry second electrodes connected together and displaced from the first electrode along the thickness dimension of the cell. The second electrodes lie within a “bulk region” of the liquid crystal bounded by the farthest extent reached by the liquid crystal in the thickness dimension. As the gap between electrodes is small, low drive voltages produce between the electrodes a significant electric field adjacent the surface.
    Type: Grant
    Filed: July 7, 2000
    Date of Patent: February 18, 2003
    Assignee: Hewlett-Packard Company
    Inventor: John Christopher Rudin
  • Patent number: 6424387
    Abstract: A device main body is formed portable, which includes (i) an information writing/erasing section which erases information recorded in a liquid crystal paper and returns the liquid crystal paper into an initialized state in which information recording is possible, and records information previously stored in the device main body into the initialized liquid crystal paper as required, and (ii) a sheet holding section which holds the liquid crystal paper in such a manner that the liquid crystal paper can be transported to an information erasure position and an information recording position in the information writing/erasing section and that the liquid crystal paper is curved at portions thereof other than those at which information recording and erasing is carried out. With this, it is possible to provide an information recording device with improved operability, such as improved portability and capability of easily reading out information at any place.
    Type: Grant
    Filed: March 7, 2001
    Date of Patent: July 23, 2002
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Eiji Sato, Shiro Narikawa, Tomoko Nishino, Masao Yamamoto
  • Publication number: 20020033928
    Abstract: A liquid crystal display is provided that includes liquid crystal pixel cells arranged at each intersection between a plurality of gate lines and a plurality of data lines, a thin film transistor associated with each pixel cell, a storage capacitor, and a smectic liquid crystal between an upper substrate and a lower substrate. The smectic liquid crystal has spontaneous polarization in a range of approximately 2 nC/cm2 to 100 nC/cm2 and a storage capacitance is in a range of approximately 1 nF/cm2 to 13 nF/cm2 for optimizing transmittance depending on the spontaneous polarization of the smectic liquid crystal.
    Type: Application
    Filed: September 4, 2001
    Publication date: March 21, 2002
    Applicant: LG Philips LCD Co., Ltd.
    Inventors: Suk Won Choi, Su Seok Choi
  • Patent number: 6351327
    Abstract: A liquid crystal pixel current sensing technique is described that increases LC (Liquid Crystal)-based micro display contrast fidelity and lowers production costs. A spatial light modulator has an electro-optical material (such as a liquid crystal layer) between an array of pixel electrodes and a common electrode (such as an indium tin oxide (ITO) layer). An amplifier biases the common electrode of the spatial light modulator and outputs a differential current proportional to the electro-optical material current. The output is used to determine delay of a light source to compensate for switching delay of the modulator. For one embodiment, the amplifier has a common-source push-pull output stage and current mirrors. For another embodiment, the output stage is a cascode common-source push-pull output stage. Because the current sensor does not perform current-to-voltage conversion, it does not alter the impedance between the pixel driver and the pixel electrode.
    Type: Grant
    Filed: May 30, 2000
    Date of Patent: February 26, 2002
    Assignee: Agilent Technologies, Inc.
    Inventor: Hugh M Walsh
  • Publication number: 20010005249
    Abstract: An electrooptic device (2), and the methods for manufacturing, including a liquid crystal material (12) disposed between electroded flat glass or polymer substrates (4, 20) which have been precoated with a e.g. a chiral smectic surface layer (10, 14) in such way that the surface layer is able to mediate switching of the liquid crystal (12) between different optical states. The chiral smectic surface layer can be a polymer, oligomer or monomer liquid crystal with paraelectric, ferroelectric, ferrielectric or antiferroelectric response, which is insoluble in the liquid crystal used for the bulk (12) between the electroded substrates (4, 20). the switchable surface director enforces a certain orientation of the optic axis in the bulk liquid crystal (12), which can be a conventional non-chiral or chiral nematic or smectic in a twisted or non-twisted configuration.
    Type: Application
    Filed: January 5, 2001
    Publication date: June 28, 2001
    Inventors: Bengt Stebler, Dietrich Demus, Torbjorn Lagerwall, Lachezar Komitov
  • Patent number: 6198523
    Abstract: A ferroelectric liquid crystal-based switchable half-wave plate with improved alignment control, a ferroelectric liquid crystal-based light valve system with improved contrast control, and a method of improving contrast in a ferroelectric liquid crystal-based light valve system. The switchable half-wave plate with improved alignment control includes a layer of ferroelectric liquid crystal material sandwiched between a first transparent electrode and a second transparent electrode. The switchable half-wave plate also includes an electric field direction switching circuit configured to switch the electric field across the liquid crystal material between the forward direction and the reverse direction in response to a control signal. The switchable half-wave plate additionally includes an electric field magnitude control circuit to adjust the tilt angle in response to a signal received at a alignment control signal input.
    Type: Grant
    Filed: October 28, 1999
    Date of Patent: March 6, 2001
    Assignee: Hewlett-Packard Co.
    Inventor: Rene P. Helbing
  • 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: 6163311
    Abstract: A driving method comprising providing preparatory pulses to each pixel, which establish a predetermined voltage prior to the data pulses. The preparatory pulses may either unload the pixel to a resulting potential of 0 V or load it to a resulting voltage of the same polarity as the charge on the pixel in the subsequent frame time.
    Type: Grant
    Filed: May 21, 1999
    Date of Patent: December 19, 2000
    Assignee: Rolic AG
    Inventors: Jurg Funfschilling, Martin Schadt
  • Patent number: 6141076
    Abstract: A hybrid analog/binary electro-optic modulator using a twisted ferroelectric liquid crystal structure is provided. Ferroelectric liquid crystals with a tilt angle of between about 20.degree. and about 25.degree., preferably about 22.5.degree. are used. Rubbing directions for the two cell walls (relative to one another) can be varied from about 45.degree. to about 90.degree.. In one embodiment, a weak buffing force is used resulting in a relatively weak anchoring energy at the surface, aligning the liquid crystal molecules without locking the molecules into the buffing directions and a high pre-tilt structure for the molecules close to the surface boundaries. In one embodiment, strong buffing is used with buffing directions offset about 45.degree.. Use of this invention provides relatively fast response time, low required driving voltage, high contrast, and/or the ability to achieve both analog and binary operations.
    Type: Grant
    Filed: November 28, 1997
    Date of Patent: October 31, 2000
    Assignee: Chorum Technologies, Inc.
    Inventors: Jian-Yu Liu, Kuang-Yi Wu, Seng-Ieong Wong
  • Patent number: 6139924
    Abstract: Novel liquid crystal compounds are provided which exhibit less temperature dependent switching properties, for the reliable and consistent operation of liquid crystal devices. The liquid crystal compounds comprise (a) an achiral fluorochemical terminal portion that comprises a terminal fluoroalkyl, fluoroether, perfluoroalkyl, or perfluoroether group; a chiral terminal portion comprising a saturated or unsaturated chiral hydrocarbon or chiral hydrocarbon ether group comprising a chiral center; and a central core connecting the terminal portions; said chiral terminal portion having at least three in-chain atoms (an "extended group") between said chiral center of the chiral terminal portion and said central core.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: October 31, 2000
    Assignee: 3M Innovative Properties Company
    Inventors: Michael P. Keyes, Marc D. Radcliffe, Steven J. Martin, Daniel C. Snustad, Kenneth A. Epstein
  • Patent number: 6133974
    Abstract: A ferroelectric liquid crystal display includes a pair of first and second substrates placed substantially in parallel to each other to form a space between the first and second substrates so that a ferroelectric liquid crystal is provided in the space between the first and second substrates, wherein the ferroelectric liquid crystal is isolated into coexistent separate orientation regions that have crystal orientations which differ by 90 degrees from each other in initial orientation direction of an optical axis of ferroelectric liquid crystal molecules when no electric field is applied to the ferroelectric liquid crystal immediately after the ferroelectric liquid crystal has been injected into the space between the first and second substrates.
    Type: Grant
    Filed: August 18, 1997
    Date of Patent: October 17, 2000
    Assignee: NEC Corporation
    Inventor: Toshiya Ishii
  • 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