Antiferroelectric Patents (Class 349/174)
  • Patent number: 11361729
    Abstract: An electronic display pipeline may process image data for display on an electronic display. The electronic display pipeline may include burn-in compensation statistics collection circuitry and burn-in compensation circuitry. The burn-in compensation statistics collection circuitry may collect image statistics based at least in part on the image data. The statistics may estimate a likely amount of non-uniform aging of the sub-pixels of the electronic display. The burn-in compensation circuitry may apply a gain to sub-pixels of the image data to account for non-uniform aging of corresponding sub-pixels of the electronic display. The applied gain may be based at least in part on the image statistics collected by the burn-in compensation statistics collection circuitry.
    Type: Grant
    Filed: January 3, 2018
    Date of Patent: June 14, 2022
    Assignee: Apple Inc.
    Inventors: Mahesh B. Chappalli, Christopher P. Tann, Peter F. Holland, Guy Côté, Stephan Lachowsky
  • Patent number: 10629146
    Abstract: A liquid crystal display (LCD) device and a driving method where the LCD device includes a data controller for interleaving one of black gray scale data and intermediate gray scale data into input digital video data to input digital video data in a specific period preceding a second one of two successive frame periods in which data voltages having the same polarity are successively supplied to liquid crystal cells. A timing signal controller generates a data timing signal and a gate timing signal, based on an input timing signal, and accelerates a frequency of the data timing signal and a frequency of the gate timing signal in the specific period. A data driving circuit is included for converting the interleaved digital video data into an analog voltage in response to the data timing signal, and supplying the analog voltage to data lines in the specific period.
    Type: Grant
    Filed: May 22, 2008
    Date of Patent: April 21, 2020
    Assignee: LG DISPLAY CO., LTD.
    Inventors: Hong Sung Song, Woong Ki Min, Su Hyuk Jang
  • Patent number: 9218080
    Abstract: A touch sensing type liquid crystal display device includes an array substrate includes an array substrate including a first substrate, a common electrode, a pixel electrode, and a touch sensing unit; a color filter substrate including a second substrate and facing the array substrate; an anti-static layer on an outer side of the second substrate and including an inorganic material and conductive particles; and a liquid crystal layer between the first substrate and an inner side of the second substrate.
    Type: Grant
    Filed: March 18, 2011
    Date of Patent: December 22, 2015
    Assignee: LG DISPLAY CO., LTD.
    Inventors: Kum-Mi Oh, Yong-Su An, Kyoung-Jin Nam, Han-Seok Lee
  • Patent number: 8953139
    Abstract: Example embodiments disclosed herein relate to the stabilization of the orthoconic state in orthoconic antiferroelectric liquid crystal devices. According to some of the example embodiments, the stabilization may be obtained by tuning a device cell as well as material parameters. The orthoconic state may be stabilized by means of the cell surfaces, electric fields, and/or polymer-stabilization, and combinations thereof, under selected conditions. The example embodiments presented herein advances several new working modes as well as new types of applications of orthoconic antiferroelectric liquid crystals.
    Type: Grant
    Filed: July 8, 2011
    Date of Patent: February 10, 2015
    Inventors: Sven T Lagerwall, Per Rudquist
  • Patent number: 8717508
    Abstract: A Liquid Crystal Display (LCD) device includes a liquid crystal panel in which a plurality of common electrodes are formed; an interred touch sensor for applying a common voltage to the common electrodes, and detecting a touch point of the liquid crystal panel with a capacitance that is induced in the common electrodes; a plurality of common electrode lines for connecting the common electrodes to the touch sensor; and an equivalent potential unit formed in the common electrode lines, and discharging residual electric charges of the common electrodes.
    Type: Grant
    Filed: August 31, 2011
    Date of Patent: May 6, 2014
    Assignee: LG Display Co., Ltd.
    Inventors: Jae Sung Yu, Bu Yeol Lee, In Hyuk Song
  • 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
  • Publication number: 20100171921
    Abstract: A liquid crystal display (LCD) includes two glass substrates, a liquid crystal unit formed by sandwiching a liquid crystal layer between the two glass substrates, a first polarizing film, and a second polarizing film. In another example, the LCD further includes a diffuse reflective film formed on the other side of the second polarizing film. In another example, the second polarizing film is replaced by a reflective film. The liquid crystal layer is composed of an antiferroelectric (including intermediate antiferroelectric) smectic liquid crystal material, and a birefringence of the liquid crystal layer changes along with an electric field applied to the liquid crystal layer.
    Type: Application
    Filed: January 6, 2009
    Publication date: July 8, 2010
    Applicant: INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE
    Inventors: Alexei Removich Khokhlov, Alexander Vyacheslavovich Emelyanenko, Evgeny Pavlovich Pozhidaev, Nikolay Mikhailovich Shtykov, Vadim Evgenievich Molkin, Hui-Lung Kuo, Yi-Ping Hsieh
  • Patent number: 7561246
    Abstract: A liquid crystal device comprising: a pair of substrates having an electrode arrangement thereon; an orientation control means provided on at least one of said substrates; and a ferroelectric or antiferroelectric liquid crystal layer interposed between said substrates, said liquid crystal layer being uniaxially oriented by virtue of said orientation control means, wherein means for suppressing an orientation control effect of said orientation control means with respect to said liquid crystal layer is provided between said liquid crystal layer and said orientation control means.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: July 14, 2009
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Toshimitsu Konuma, Takeshi Nishi, Michio Shimizu, Harumi Mori, Kouji Moriya, Satoshi Murakami
  • Patent number: 7123320
    Abstract: A liquid crystal electro-optical device comprising a pair of substrates at least one of them is light-transmitting, electrodes being provided on said substrates, and an electro-optical modulating layer being supported by said pair of substrates, provided that said electro-optical modulating layer comprises an anti-ferroelectric liquid crystal material or a smectic liquid crystal material which exhibits anti-ferroelectricity, and a transparent material.
    Type: Grant
    Filed: August 22, 2003
    Date of Patent: October 17, 2006
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Takeshi Nishi, Toshimitsu Konuma, Michio Shimizu, Kouji Moriya
  • Patent number: 6930750
    Abstract: A liquid crystal optical element includes two substrates, a liquid crystal layer, and at least two electrodes. The liquid crystal layer is provided between the substrates and includes liquid crystal molecules and dichroic dye molecules. The at least two electrodes are provided on the substrates so as to face each other with the liquid crystal layer interposed between them, and define one of multiple unit regions. In each unit region, the liquid crystal layer includes first and second liquid crystal regions within a range, which is approximately half or less as long as the wavelength of visible radiation as measured in a direction parallel to the surfaces of the substrates. The orientation directions of each pair of liquid crystal molecules in the first and second liquid crystal regions have azimuthal directions defining an angle of approximately 90 degrees while no voltage is being applied between the electrodes.
    Type: Grant
    Filed: October 21, 2003
    Date of Patent: August 16, 2005
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Koichi Miyachi, Seiji Shibahara
  • Patent number: 6924009
    Abstract: A liquid crystal device comprising tilted smectic phases of banana-shaped liquid crystal molecules is disclosed. 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 and permanently disposing at least one banana-shaped liquid crystal material into said cell gap. The present invention also provides a method of generating an image, comprising providing a pair of substrates with a cell gap therebetween, providing transparent electrodes on each of the substrates adjacent to the cell gap, disposing at least one banana-shaped liquid crystal material into the cell gap; and applying an electric field across the electrodes. The tilted smectic phases of banana-shaped liquid crystal may be in either a racemic or a chiral state.
    Type: Grant
    Filed: October 26, 2001
    Date of Patent: August 2, 2005
    Assignee: Kent State University
    Inventors: Antal Jakli, Liang-Chy Chien, Daniel Krüerke, Hans Sawade, Gerd Heppke
  • Patent number: 6919950
    Abstract: The invention relates to a liquid crystal device, comprising an antiferroelectric liquid crystal material (AFLC material) having smectic layers, and two substrates confining the AFLC material therebetween, wherein the AFLC material is uniaxial negative. Preferably, the AFLC material is uniaxial as a consequence of a surface stabilization and of a selected smectic tilt angle ? of the AFLC material. Preferably, the angle ? is in the range of 40°???50°, especially 45°. The invention also relates to electrooptic liquid crystal devices.
    Type: Grant
    Filed: August 28, 2001
    Date of Patent: July 19, 2005
    Inventors: Roman S. Dabrowski, Witold J. Drzewinski, Herman Pauwels, Anders Dahlgren, Sven T. Lagerwall, Per Rudquist, Koen D'Have, Marek Matuszcyk, Pontus Jagemalm
  • Patent number: 6888527
    Abstract: An antiferroelectric liquid crystal panel, having an antiferroelectric liquid crystal between a pair of substrates, which comprises a driving circuit adapted to output a layer structure controlling voltage waveform having a frequency of 1 Hz to 100 Hz and a voltage in the range of +10 V to +50 V or ?10 V to ?50 V, for an optional length of time.
    Type: Grant
    Filed: October 19, 2001
    Date of Patent: May 3, 2005
    Assignee: Citizen Watch Co., Ltd.
    Inventor: Shinya Kondoh
  • Patent number: 6876426
    Abstract: There is a liquid crystal display element capable of obtaining a good display performance which is not influenced by the deterioration with the time course and the history of applied voltage.
    Type: Grant
    Filed: March 10, 2004
    Date of Patent: April 5, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Rieko Fukushima, Kohki Takatoh
  • Patent number: 6765643
    Abstract: There is a liquid crystal display element capable of obtaining a good display performance which is not influenced by the deterioration with the time course and the history of applied voltage.
    Type: Grant
    Filed: December 20, 2000
    Date of Patent: July 20, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Rieko Fukushima, Kohki Takatoh
  • Patent number: 6703993
    Abstract: A driving method for a liquid crystal device comprising a pair of electrodes and a liquid crystal disposed between the electrodes includes a sequence of voltage application operations each comprising application of a reset voltage to the liquid crystal for placing the liquid crystal in a reset state in a reset period and application of a data voltage to the liquid crystal for placing the liquid crystal in a desired gradational display state in a writing period subsequent to the reset period. Each reset voltage is set to provide a prescribed difference in voltage between the each reset voltage and a subsequent data voltage, thus preventing an image memory phenomenon without using an additional reset circuit for exclusively applying the reset voltage to the liquid crystal.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: March 9, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventors: Seishi Miura, Hirohide Munakata, Hideo Mori
  • Patent number: 6630981
    Abstract: A ferroelectric liquid crystal display includes a pair of first and second substrates placed substantially in parallel to each other to form a space between the first and second substrates so that a ferroelectric liquid crystal is provided in the space between the first and second substrates, wherein the ferroelectric liquid crystal is isolated into co-existent separate orientation regions that have crystal orientations which differ by 90 degrees from each other in initial orientation direction of an optical axis of ferroelectric liquid crystal molecules when no electric field is applied to the ferroelectric liquid crystal immediately after the ferroelectric liquid crystal has been injected into the space between the first and second substrates.
    Type: Grant
    Filed: December 17, 2001
    Date of Patent: October 7, 2003
    Assignee: NEC Corporation
    Inventor: Toshiya Ishii
  • Patent number: 6618105
    Abstract: A liquid crystal electro-optical device comprising a pair of substrates at least one of them is light-transmitting, electrodes being provided on said substrates, and an electro-optical modulating layer being supported by said pair of substrates, provided that said electro-optical modulating layer comprises an anti-ferroelectric liquid crystal material or a smectic liquid crystal material which exhibits anti-ferroelectricity, and a transparent material.
    Type: Grant
    Filed: February 13, 2001
    Date of Patent: September 9, 2003
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Takeshi Nishi, Toshimitsu Konuma, Michio Shimizu, Kouji Moriya
  • 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: 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: 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
  • 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: 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
  • Publication number: 20020075445
    Abstract: The invention relates to a liquid crystal device, comprising an antiferroelectric liquid crystal material (AFLC material) having smectic layers, and two substrates confining said AFLC material therebetween, wherein said AFLC material is uniaxial negative. Preferably, the AFLC material is uniaxial as a consequence of a surface stabilization and of a selected smectic tilt angle &thgr; of said AFLC material. Preferably, said angle &thgr; is in the range of 40°<&thgr;<50°, especially 45°. The invention also relates to electrooptic liquid crystal devices.
    Type: Application
    Filed: August 28, 2001
    Publication date: June 20, 2002
    Inventors: Roman S. Dabrowski, Witold J. Drzewinski, Herman Pauwels, Anders Dahlgren, Sven T. Lagerwall, Per Rudquist, Koen D'Have, Marek Matuszcyk, Pontus Jagemalm
  • Patent number: 6369872
    Abstract: An antiferroelectric liquid crystal display having: a temperature sensor for measuring the temperature of a liquid crystal panel (10); a heater (102) for heating the liquid crystal panel (10); and a heater control circuit (17) for controlling the temperature of the liquid crystal panel (10), wherein the liquid crystal panel (10), while being driven to produce a display, is maintained at a temperature at which smectic layer spacing in an antiferroelectric liquid crystal material sandwiched within the liquid crystal panel (10) becomes the smallest. In this antiferroelectric liquid crystal display, when the temperature of the liquid crystal panel (10), after power on, has reached the temperature at which the smectic layer spacing in the antiferroelectric liquid crystal material becomes the smallest, a layer structure control voltage waveform is applied to the liquid crystal panel (10).
    Type: Grant
    Filed: May 24, 1999
    Date of Patent: April 9, 2002
    Assignee: Citizen Watch Co., Ltd.
    Inventor: Shinya Kondoh
  • Publication number: 20020024629
    Abstract: A liquid crystal electro-optical device comprising a pair of substrates at least one of them is light-transmitting, electrodes being provided on said substrates, and an electro-optical modulating layer being supported by said pair of substrates, provided that said electro-optical modulating layer comprises an anti-ferroelectric liquid crystal material or a smectic liquid crystal material which exhibits anti-ferroelectricity, and a transparent material.
    Type: Application
    Filed: February 13, 2001
    Publication date: February 28, 2002
    Inventors: Shunpei Yamazaki, Takeshi Nishi, Toshimitsu Konuma, Michio Shimizu, Kouji Moriya
  • Patent number: 6344890
    Abstract: A ferroelectric liquid crystal display includes a pair of first and second substrates placed substantially in parallel to each other to form a space between the first and second substrates so that a ferroelectric liquid crystal is provided in the space between the first and second substrates, wherein the ferroelectric liquid crystal is isolated into co-existent separate orientation regions that have crystal orientations which differ by 90 degrees from each other in initial orientation direction of an optical axis of ferroelectric liquid crystal molecules when no electric field is applied to the ferroelectric liquid crystal immediately after the ferroelectric liquid crystal has been injected into the space between the first and second substrates.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: February 5, 2002
    Assignee: NEC Corporation
    Inventor: Toshiya Ishii
  • Patent number: 6339416
    Abstract: In a liquid crystal display comprising a liquid crystal panel with an antiferroelectric liquid crystal sandwiched between a pair of substrates having scanning electrodes and signal electrodes, a display driving voltage waveform in which the peak value of a scanning voltage waveform applied during a selection period is set equal to the peak value of a scanning voltage waveform applied during a non-selection period is output as a layer structure controlling voltage waveform for a predetermined length of time. The liquid crystal panel includes a temperature sensor, and in accordance with the information output from the temperature sensor, the display driving voltage waveform with both peak values set equal is output as the layer structure controlling voltage waveform for the optional length of time.
    Type: Grant
    Filed: November 9, 1999
    Date of Patent: January 15, 2002
    Assignee: Citizen Watch Co., Ltd.
    Inventor: Shinya Kondoh
  • 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
  • Patent number: 6266115
    Abstract: A liquid crystal cell and liquid crystal display device include: two electrode substrates facing each other through a plurality of spacers; each electrode substrate being formed by superimposing a glass substrate, a transparent electrode and an alignment film; and an antiferroelectric liquid crystal being injected between alignment films; wherein, an alignment treatment is performed to each alignment film so that an angle of layer rotation of the antiferroelectric liquid crystal is defined within a predetermined allowable range.
    Type: Grant
    Filed: September 9, 1996
    Date of Patent: July 24, 2001
    Assignees: Nippondenso Co., Ltd., Nippon Soken, Inc.
    Inventors: Takayuki Fujikawa, Akira Takeuchi, Norio Yamamoto, Yuichiro Yamada, Masaaki Ozaki
  • Patent number: 6259492
    Abstract: An antiferroelectric liquid crystal display apparatus free from burn-in and achieving high display quality is provided by providing means for preventing pixel brightness from varying between pixels continuously held in an ON (bright) state and pixels continuously held in an OFF (dark) state. Aging processing is performed to saturate the brightness level of pixels into a stable state and thereby prevent the occurrence of a white brightening phenomenon. For this purpose, the brightness at a no voltage condition (base brightness) is set to a normalized level for all pixels in the liquid crystal panel that are required to exhibit uniform display performance. Further, temperature variations in the liquid crystal panel are eliminated to stabilize the brightness level and thereby prevent the occurrence of a white darkening phenomenon. Means is also provided for repeatedly performing normalization processes automatically or manually.
    Type: Grant
    Filed: October 8, 1998
    Date of Patent: July 10, 2001
    Assignee: Citizen Watch Co., Ltd.
    Inventors: Satoshi Imoto, Heihachiro Ebihara
  • 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
  • Publication number: 20010005248
    Abstract: There is a liquid crystal display element capable of obtaining a good display performance which is not influenced by the deterioration with the time course and the history of applied voltage.
    Type: Application
    Filed: December 20, 2000
    Publication date: June 28, 2001
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Rieko Fukushima, Kohki Takatoh
  • Patent number: 6208402
    Abstract: In an antiferroelectric liquid crystal panel, in which a plurality of strip-shaped first and second transparent electrodes are formed on a pair of first and second substrates, the substrates are opposedly disposed so that the transparent electrodes intersect with each other at right angles, and the antiferroelectric liquid crystal is filled in a gap thereinbetween, at least at the positions corresponding to intersecting portions of the gaps between a plurality of first transparent electrodes and the gaps between a plurality of second transparent electrodes. Spacers are fixed on the first substrate and made of insulating material, a first alignment layer is formed to cover at least the first transparent electrodes on the first substrate, and a second alignment layer is formed to cover the second transparent electrodes on the second substrate.
    Type: Grant
    Filed: September 15, 1998
    Date of Patent: March 27, 2001
    Assignee: Citizen Watch Co., Ltd.
    Inventor: Eiichi Tajima
  • Patent number: 6195139
    Abstract: A liquid crystal electro-optical device comprising a pair of substrates at least one of them is light-transmitting, electrodes being provided on said substrates, and an electro-optical modulating layer being supported by said pair of substrates, provided that said electro-optical modulating layer comprises an anti-ferroelectric liquid crystal material or a smectic liquid crystal material which exhibits anti-ferroelectricity, and a transparent material.
    Type: Grant
    Filed: July 2, 1996
    Date of Patent: February 27, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Takeshi Nishi, Toshimitsu Konuma, Michio Shimizu, Kouji Moriya
  • Patent number: 6195137
    Abstract: A liquid crystal apparatus is constituted from a liquid crystal device including a first substrate having thereon a plurality of scanning lines, a plurality of data lines intersecting the scanning lines, an active element disposed at each intersection of the scanning lines and data lines, a plurality of pixel electrodes each connected to the scanning line and the data line via the active element and defining a pixel, a second substrate having a counter electrode thereon, and a ferroelectric liquid crystal disposed between the first and second substrates and capable of assuming an anti-ferroelectric state under application of no voltage and a first ferroelectric state and a second ferroelectric state under application of voltages corresponding to polarities of the applied voltages.
    Type: Grant
    Filed: November 3, 1995
    Date of Patent: February 27, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yutaka Inaba, Akira Tsuboyama, Shinichi Nakamura
  • Patent number: 6175401
    Abstract: A liquid crystal material which exhibits an antiferroelectric phase while the liquid crystal material is in a bulk state, is sealed between substrates. The liquid crystal layer sealed between the substrates exhibits a mixed phase wherein the liquid crystal layer contains liquid crystal molecules aligned in a plurality of alignment states which differ from each other in the alignment order of the liquid crystal molecules forming adjoining smectic layers. The direction of the director of the liquid crystal layer varies continuously in accordance with the polarity and magnitude of a voltage applied to the liquid crystal layer. Gradation display can be achieved by arranging polarization plates such that the substrates are sandwiched therebetween.
    Type: Grant
    Filed: May 1, 1998
    Date of Patent: January 16, 2001
    Assignee: Casio Computer Co., Ltd.
    Inventors: Tomio Tanaka, Tetsushi Yoshida, Jun Ogura, Manabu Takei
  • Patent number: 6172727
    Abstract: The present invention relates to a structure of a liquid crystal (LC) cell using an antiferroelectric liquid crystal. The LC cell includes: an electrode substrate with color filters; an opposite electrode substrate; a first alignment film provided on the electrode substrate with color filters; a second alignment film provided on the opposite electrode substrate; an antiferroelectric liquid crystal provided between the first and second alignment films; and the electrode substrate with color filters and the opposite electrode substrate being superimposed so as to face each other through the first alignment film, the antiferroelectric liquid crystal, and the second alignment film. In the present invention, an alignment process of the first alignment film is performed based on a rubbing density larger than the rubbing density of the second alignment film so that an angle of layer rotation of the antiferroelectric liquid crystal is defined within a predetermined allowable angle range.
    Type: Grant
    Filed: March 31, 1998
    Date of Patent: January 9, 2001
    Assignee: Denso Corporation
    Inventors: Masaaki Ozaki, Tetsuya Sano, Takayuki Fujikawa, Norio Yamamoto
  • Patent number: 6163360
    Abstract: Placed between a pair of substrates is a liquid crystal which has a first ferroelectric phase where liquid crystal molecules are aligned substantially in a first direction in accordance with an applied voltage, a second ferroelectric phase where the liquid crystal molecules are aligned substantially in a second direction in accordance with an applied voltage, and an intermediate alignment state where the director of the liquid crystal is directed between the first and second directions. The liquid crystal in use is selected so that the first and second directions intersect each other at an angle of greater than 45.degree.. The transmission axis of one of a pair of polarization plates is set inclined to an intermediate direction between the first and second directions by 22.5.degree., and the optical axis of the other polarization plate is set perpendicular to the transmission axis of the former polarization plate.
    Type: Grant
    Filed: June 19, 1997
    Date of Patent: December 19, 2000
    Assignee: Casio Computer Co., Ltd.
    Inventors: Tomio Tanaka, Jun Ogura, Satoru Shimoda, Tetsushi Yoshida
  • Patent number: 6151095
    Abstract: An antiferroelectric liquid crystal cell having a high-speed response and wide viewing angle characteristic free of an image sticking phenomenon is provided. This antiferroelectric liquid crystal cell is composed of an antiferroelectric liquid crystal material held between a pair of parallel substrates. The antiferroelectric liquid crystal material filled between the parallel substrates has such a characteristic that when a sinusoidal voltage value with a changing reference frequency is applied to the antiferroelectric liquid crystal cell, the imaginary part of the complex dielectric constant obtained by Fourier transform of the output voltage value output from the antiferroelectric liquid crystal cell has no local maximum value within the reference frequency range of 100 Hz to 5 kHz.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: November 21, 2000
    Assignees: Citizen Watch Co., Ltd., Mitsubishi Gas Chemical Company, Inc.
    Inventors: Yasushi Suzuki, Akira Suguro, Tomoyuki Yui, Masahiro Johno, Takahiro Matsumoto
  • Patent number: 6151090
    Abstract: A liquid crystal cell is formed by bonding a first substrate on which a first electrode and a first aligning film are formed, and a second substrate on which a second electrode and a second aligning film are formed by a seal member. A liquid crystal is filled in the liquid crystal cell. The thicknesses of the aligning films are set to 10 nm to 35 nm. An aligning treatment is performed twice on each of the aligning films in the opposite directions. The first aligning treatment is performed to give a pretilt angle of 5 degrees to the liquid crystal, and the second aligning treatment is performed to give a pretilt angle of 6 degrees to the liquid crystal, with the result that a pretilt angle of 1 degree is actually given to the liquid crystal. The glass-transition temperatures of the aligning films are selected to be about 250.degree. C., so that the aligning films are not transformed at the time of baking the seal member.
    Type: Grant
    Filed: May 28, 1996
    Date of Patent: November 21, 2000
    Assignee: Casio Computer Co., Ltd.
    Inventors: Tomio Tanaka, Jun Ogura, Tetsushi Yoshida
  • 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: 6133896
    Abstract: The invention relates to an improvement in the contrast of an antiferroelectric liquid crystal cell which is constructed with an antiferroelectric liquid crystal sandwiched between a pair of substrates. The antiferroelectric liquid crystal cell has a layer structure such that when a Fourier transform is applied to an output voltage produced as a result of the application of a sinusoidal voltage as a reference frequency to the liquid crystal cell, the transformed output voltage contains frequency components at odd and even multiples of the reference frequency, and the optical path length of the liquid crystal cell lies in the range of 100 nm to 800 nm.
    Type: Grant
    Filed: October 5, 1998
    Date of Patent: October 17, 2000
    Assignee: Citizen Watch Co., Ltd.
    Inventor: Yasushi Suzuki
  • Patent number: 6122034
    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: August 27, 1998
    Date of Patent: September 19, 2000
    Assignee: Casio Computer Co., Ltd.
    Inventors: Tomio Tanaka, Tetsushi Yoshida, Jun Ogura, Satoru Shimoda
  • Patent number: 6083574
    Abstract: An aligning method of a chiral smectic liquid crystal includes the steps of: disposing a chiral smectic liquid crystal between a pair of electrode plates, the chiral smectic liquid crystal having a layer spacing-changing characteristic providing a layer spacing which increases on temperature decrease in a first temperature range in smectic A phase; and subjecting the chiral smectic liquid crystal to a heat treatment including a sequence of cooling from a higher temperature phase to a second temperature range in smectic A phase including at least a portion of the first temperature range, at least one cycle of heating and cooling within the second temperature range, and further cooling to a smectic phase lower than smectic phase. The heat treatment, particularly at least one cycle of heating and cooling in smectic A phase, is effective in suppressing an alignment (orientation) irregularity due to the presence of two regions different in characteristics, thus improving a drive margin.
    Type: Grant
    Filed: July 28, 1998
    Date of Patent: July 4, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasufumi Asao, Yukio Hanyu, Koichi Sato, Masahiro Terada, Koji Noguchi
  • Patent number: 6057007
    Abstract: A tristable liquid crystal display device comprises (a) first and second opposed substrates, at least one bearing an alignment coating and each bearing at least one electrode so as to define one or a plurality of pixels; (b) a tilted smectic or induced tilted smectic liquid crystal composition disposed between the substrates; and (c) a pair of orthogonally disposed polarizers, each having a polarization axis, one polarization axis being aligned with the zero field optical axis of a tilted smectic or induced tilted smectic mesophase of the liquid crystal composition; wherein the substrates are disposed so as to provide an alignment of the liquid crystal composition, the composition comprising at least one chiral liquid crystal compound that can be represented by the following formula:R--M--N--(P).sub.b --OCH.sub.2 C*HF--CH.sub.2 O(CH.sub.2).sub.a R.sub.
    Type: Grant
    Filed: August 10, 1998
    Date of Patent: May 2, 2000
    Assignee: 3M Innovative Properties Company
    Inventors: Takashi Amano, Michael P. Keyes, Steven J. Martin, Marc D. Radcliffe, Patricia M. Savu, Daniel C. Snustad
  • Patent number: 6046790
    Abstract: A liquid crystal display device is constituted so that liquid crystal having an inherent spontaneous polarization or a spontaneous polarization induced by applying an electric field is interposed between a pixel electrode disposed in matrix and a counter electrode, and a display signal is applied to the pixel electrode through a switching element. In the liquid crystal display device constituted mentioned above, when an electrostatic capacitance of one pixel is C.sub.LC (F), a spontaneous polarization per unit electrode area of the liquid crystal is P.sub.s (C/m.sup.2), a voltage applied between the pixel electrode and the counter electrode is E (V), a pixel electrode area of one pixel is A (m.sup.2), and a storage capacitance for one pixel is C.sub.s (F), they satisfy the following equation;P.sub.s .times.A.ltoreq.5.times.(C.sub.s +C.sub.LC).times.E(1)Thereby, a display of high contrast and high response speed can be obtained.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: April 4, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yujiro Hara, Hisao Fujiwara, Takeshi Yamaguchi, Goh Itoh, Masahiko Akiyama, Haruhiko Okumura
  • Patent number: 6046788
    Abstract: A liquid crystal material is sealed between substrates. The liquid crystal material exhibits an antiferroelectric phase while the liquid crystal is in a bulk state. In the liquid crystal layer sealed between the substrates, due to aligning forces of alignment films, liquid crystal molecules are aligned in a state wherein there is no correlation in molecular order between adjoining smectic layers, and the director of the liquid crystal layer is substantially coincident with the direction of a normal line of the smectic layers. The director varies continuously in accordance with the polarity and magnitude of a voltage applied between electrodes formed on the substrates. Arranging polarization plates so that the substrates are sandwiched therebetween enables a gradation to be displayed.
    Type: Grant
    Filed: May 6, 1998
    Date of Patent: April 4, 2000
    Assignee: Casio Computer Co., Ltd.
    Inventors: Tomio Tanaka, Tetsushi Yoshida, Manabu Takei, Jun Ogura
  • Patent number: 6040889
    Abstract: A novel liquid crystal display device which enables continuous gray-scale display, has a wide viewing angle and readily allows an active-matrix drive. The liquid crystal display device has a pair of substrates and a liquid crystal material having an antiferroelectric phase sandwiched between said pair of substrates, at least one of the substrates undergoing an aligning process. In the liquid crystal display element, a natural helical pitch of the liquid crystal material is smaller than a gap between the substrates, and moreover, smaller than twice a lower-limit wavelength of the wavelength range of light used in the liquid crystal display device.
    Type: Grant
    Filed: December 23, 1997
    Date of Patent: March 21, 2000
    Assignee: NEC Corporation
    Inventors: Ken-Ichi Takatori, Ken Sumiyoshi