Patents Examined by Richard F. Gallivan
  • Patent number: 4958916
    Abstract: A liquid crystal device including a ferroelectric liquid crystal disposed between plates treated to enforce a particular ferroelectric molecular orientation to the plates. The devices employ alone or in combination non-planar boundary conditions, polar boundary conditions, boundaries with multiple physical states, intrinsic spontaneous splay distortion of the polarization orientation field, combined ferroelectric and dielectric torques, layers tilted with respect to the plates. The plates are spaced by a distance sufficiently small to ensure unwinding of the helix typical in a bulk of the material to form either monostable, bistable or multistable states which exhibit novel electro-optic properties. The liquid crystal is responsive to an externally applied electric field, temperature or the like to make a light valve or other electro-optical device.
    Type: Grant
    Filed: March 3, 1989
    Date of Patent: September 25, 1990
    Inventors: Noel A. Clark, Sven T. Lagerwall
  • Patent number: 4906073
    Abstract: In a liquid crystal display device, light transmitting through a liquid crystal layer is colored depending on the structural conditions of the liquid crystal display device. The phase of the transmission light is corrected by means of a phase correction plate to make the transmission light approximate achromatic color, thereby permitting monochromatic display or color display.
    Type: Grant
    Filed: July 27, 1988
    Date of Patent: March 6, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Katuyuki Hunahata, Yuji Mori, Jun-ichi Hirakata, Yoshiharu Nagae, Hideaki Kawakami, Kiyoshige Kinugawa, Yasuhiko Kando
  • Patent number: 4904065
    Abstract: A liquid crystal optical element comprising: (a) an oriented ferroelectric liquid-crystalline polymer layer which exhibits chiral smectic C phase, and (b) two electrically conducting layers which support the oriented ferroelectric liquid-crystalline polymer layer between them, where at least one of the two electrically conducting layers is transparent. The liquid crystal optical element can be easily made into one having a large area and can be used as a flexible display screen. Further, it has excellent electric field response property and high contrast. Furthermore, the production of the liquid crystal optical element and the control of its thickness can be easily conducted.
    Type: Grant
    Filed: June 22, 1988
    Date of Patent: February 27, 1990
    Assignee: Idemitsu Kosan Co., Ltd.
    Inventors: Kimihiro Yuasa, Kenji Hashimoto, Shunji Uchida, Kazuharu Morita, Satoshi Hachiya
  • Patent number: 4890902
    Abstract: A light modulating material comprising phase-separated microdroplets of liquid crystal in a light transmissive, synthetic resin matrix wherein the index of refraction n.sub.p of the matrix is matched or mismatched to an index of refraction N.sub.o of the liquid crystal optical axis of the microdroplets so that when the microdroplet director is aligned relative to a surface of the material, maximum transmission of light occurs at a selected oblique angle relative to the surface of the material or at a selected narrow angle about the perpendicular to the surface of the material. Such matching or mismatching of indices of refraction may be accompanied by phase separation in an external magnetic or electric field, or by shaping the liquid crystal microdroplet into an ovoid or the like during or after phase separation to align the microdroplet directors thereby endowing the material with a permanent and movable viewing angle.
    Type: Grant
    Filed: February 23, 1988
    Date of Patent: January 2, 1990
    Assignee: Kent State University
    Inventors: J. William Doane, Eugene P. Wenninger, John West, Bao-Gang Wu
  • Patent number: 4884876
    Abstract: An achromatic liquid-crystal shutter with high dynamic range, good transmission, and high speed. The inventive shutter reduces the phenomenon of "ghosting" (image doubling) that typically occurs in conventional plano-stereoscopic CRT displays due to the low dynamic range of surface mode liquid crystal electro-optical shutters included within such displays. The inventive shutter reduces crosstalk, thus allowing comfortable fusion to take place. In one preferred embodiment, the inventive shutter system is driven by a carrier-less voltage signal having time-averaged voltage substantially equal to zero, so that a simple, low power driving circuit suffices to drive the shutter. A pair of the inventive achromatic shutters may be employed in a wireless mode as a selection device for a field-sequential stereoscopic electronic display system.
    Type: Grant
    Filed: November 2, 1988
    Date of Patent: December 5, 1989
    Assignee: Stereographics Corporation
    Inventors: Lenny Lipton, Arthur Berman, Lawrence D. Meyer
  • Patent number: 4869577
    Abstract: A liquid crystal display device comprises a pair of substrates each provided with a transparent electrode, and a ferroelectric liquid crystal disposed therebetween. One of the substrates has thereon a homogeneous alignment, and the other substrate has thereon a tilted alignment film for aligning liquid crystal molecules in contact therewith in a tilted direction with respect to the face thereof. The combination of the two-types of alignment films provides a monodomain of uniformly aligned ferroelectric liquid crystal molecules, which leads to an improved display characteristic including increased contrast.
    Type: Grant
    Filed: July 21, 1987
    Date of Patent: September 26, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yuichi Masaki
  • Patent number: 4859037
    Abstract: The present invention provides an improved positive type liquid crystal display device in the birefringence mode, wherein at least one of the polarizers is a colored polarizer including the character of making the background color of the display approximately white, thereby improving the contrast ratio extremely. Further, in the negative type liquid crystal display device, a color filter for absorbing the light of the wavelength area which transmits at the time of an off state and non-selecting, is provided in series with respect to a light source and the liquid crystal display portion, thereby preventing the color shading of the background color.
    Type: Grant
    Filed: November 5, 1987
    Date of Patent: August 22, 1989
    Assignee: Seiko Epson Corporation
    Inventors: Yukihiro Iwashita, Masashi Mochizuki
  • Patent number: 4856876
    Abstract: The present invention relates to use of liquid crystal material encapsulated in a containment medium to produce a controlled colored output, for example, in response to the application, removal and variation in an electric field. In one embodiment a non-pleochroic dye is in the containment medium itself and in another embodiment the non-pleochroic dye is in the liquid crystal material itself; and in both cases the dye preferably is fluorescent or a combination of fluorescent and non-fluorescent, and the object is to color light and/or to whiten or to brighten the light emitted out from a display embodying the invention.
    Type: Grant
    Filed: June 23, 1986
    Date of Patent: August 15, 1989
    Assignee: Manchester R & D Partnership
    Inventor: James L. Fergason
  • Patent number: 4844597
    Abstract: A liquid crystal device comprising a pair of base plates and a liquid crystal composition interposed between the pair of base plates; the liquid crystal composition comprising a liquid crystal compound showing at least chiral smectic phase and a liquid crystal showing at least nematic phase and having a pyrimidine skeleton; a face of at least one of the pair of base plates having been provided with a function of preferentially orienting the axes of the liquid crystal molecules contacting the face in one direction.
    Type: Grant
    Filed: July 20, 1988
    Date of Patent: July 4, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazuharu Katagiri, Kazuo Yoshinaga, Shinjiro Okada, Junichiro Kanbe
  • Patent number: 4842377
    Abstract: A liquid crystal device includes a pair of first and second opposed substrates, a ferroelectric liquid crystal filled in a space defined between both the substrates, and a thin film transistor formed on at least one of the substrates. The thin film transistor is used as a spacer between the substrates, and the spacer is bonded to the first substrate opposed to the second substrate on which the spacer is formed. In another aspect, a dummy corresponding to the thin film transistor is further provided on the substrate on which the thin film transistor is formed, wherein the dummy is used as a spacer.
    Type: Grant
    Filed: April 12, 1988
    Date of Patent: June 27, 1989
    Assignee: Alps Electric Co., Ltd.
    Inventor: Jun Nakanowatari
  • Patent number: 4840462
    Abstract: By using an auxiliary signal bringing a ferroelectric liquid crystal to an extreme transmission state in an active matrix it is impossible for successive charge compensation to occur on the pixels. This prevents the growth of regions where transmission occurs or does not occur and provides the possibility of obtaining gray scales in a reproducible manner.
    Type: Grant
    Filed: February 25, 1988
    Date of Patent: June 20, 1989
    Assignee: U.S. Philips Corporation
    Inventor: Wilbert J. A. M. Hartmann
  • Patent number: 4838660
    Abstract: The present invention relates to use of liquid crystal material encapsulated in a containment medium to produce a controlled colored output, for example, in response to the application, removal and variation in an electric field. In one embodiment a non-pleochroic dye is in the containment medium itself and in another embodiment the non-pleochroic dye is in the liquid crystal material itself; and in both cases the object is to color light.
    Type: Grant
    Filed: March 18, 1986
    Date of Patent: June 13, 1989
    Assignee: Manchester R & D Partnership
    Inventor: James L. Fergason
  • Patent number: 4838663
    Abstract: A new liquid crystal electro-optic device similar to the SSFLC device is described. It uses the same kind of polar chiral smectics and the same geometry as the SSFLC device (thin sample in the "book-shelf" layer arrangement) but instead of using a tilted smectic phase like the C* phase, it utilizes the above-lying, essentially non-ferroelectric A phase. The achievable optical intensity modulation is considerably lower than for the SSFLC device, but the device is about one hundred times faster. It is thus appropriate for modulator rather than for display applications. Sample fabrication is simpler and, finally, the device is insensitive to polarization compensation from external charges. The electro-optic switching at moderate applied voltages can be detected through the full range of the A phase.
    Type: Grant
    Filed: October 7, 1987
    Date of Patent: June 13, 1989
    Assignee: S.A.R.L. S.T. Lagerwall
    Inventors: Sven T. Lagerwall, Gunnar Andersson, Ingolf Dahl, Wojciech Kuczynski, Kent Sharp, Bengt Stebler
  • Patent number: 4836655
    Abstract: An improved liquid crystal device which is driven by applying electric field thereon is shown. The device includes a ferroelectric liquid crystal layer which is separated into pixels and whose optical nature is changed by the electric field induced therein. Contiguous to the liquid crystal layer, a semiconductor charge storage layer is provided to give hysteresis to the device.
    Type: Grant
    Filed: February 17, 1987
    Date of Patent: June 6, 1989
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Shunpei Yamazaki
  • Patent number: 4826300
    Abstract: An LCLV is formed with a sapphire substrate base, a highly doped, thin silicon epitaxial layer forming an ohmic back contact on a smooth surface of the sapphire substrate, and a lightly doped, high resistivity silicon epitaxial layer in the range of about 20-60 microns thick on the back contact. The use of a sapphire substrate provides a better surface quality and higher resolution than previously available with the semiconductor substrates. Lattice defects in the thin back contact are reduced by the formation of a buried amorphous layer adjacent the sapphire substrate, and subsequent recrystallization thereof using the unamorphized portions of the back contact as recrystallization seeds. The application of the invention to both MOS and Schottky diode LCLVs is discussed.
    Type: Grant
    Filed: July 30, 1987
    Date of Patent: May 2, 1989
    Assignee: Hughes Aircraft Company
    Inventors: Uzi Efron, Paul O. Braatz, Prahalad K. Vasudev, Glenn D. Robertson
  • Patent number: 4824218
    Abstract: A driving system is disclosed, wherein a potential gradient is formed in a pixel and is utilized for driving. Particularly, there is disclosed an optical modulation apparatus, comprising: a first substrate having thereon a conductor film, and a plurality of transmission lines disposed electrically connected to the conductor film; a second substrate; an optical modulation material disposed between the first and second substrate; and means for supplying a pair of electric signals in mutually opposite transmission directions to neighboring transmission lines among the plurality of transmission lines.
    Type: Grant
    Filed: April 2, 1987
    Date of Patent: April 25, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Mitsutoshi Kuno, Masahiko Enari, Hitoshi Shindo, Isamu Shimoda, Seishiro Yoshioka, Shuzo Kaneko, Tsutomu Toyono
  • Patent number: 4824216
    Abstract: The device of the invention comprises mainly a liquid crystal screen illuminated by a light source. An electrically controlled modulating device is placed between the source and the screen. Depending on the desired illuminating intensity, the electrical signal will be adapted to the modulating device. The modulating device may comprise essentially a liquid crystal cell.
    Type: Grant
    Filed: April 20, 1987
    Date of Patent: April 25, 1989
    Assignee: Thomson-CSF
    Inventors: Jean N. Perbet, Michel Hareng, Bruno Mourey
  • Patent number: 4820027
    Abstract: An achromatic liquid-crystal shutter with high dynamic range, good transmission, and high speed. The inventive shutter reduces the phenomenon of "ghosting" (image doubling) that typically occurs in conventional plano-stereoscopic CRT displays due to the low dynamic range of surface mode liquid crystal electro-optical shutters included within such displays. The inventive shutter reduces crosstalk, thus allowing comfortable fusion to take place. In one preferred embodiment, the inventive shutter system is driven by a carrier-less voltage signal having time-average voltage substantially equal to zero, so that a simple, low power driving circuit suffices to drive the shutter. A pair of the inventive achromatic shutters may be employed in a wireless mode as a selection device for a field-sequential stereoscopic electronic display system.
    Type: Grant
    Filed: October 30, 1987
    Date of Patent: April 11, 1989
    Assignee: StereoGraphics Corporation
    Inventors: Lenny Lipton, Arthur Berman, Lawrence D. Meyer
  • Patent number: 4820026
    Abstract: A liquid crystal device comprises a pair of parallel substrates and a ferroelectric liquid crystal disposed between the substrates so as to have an arrangement of molecules forming a plurality of layers perpendicular to the faces of the substrates. At least one of the pair of substrates has an alignment control film formed of a modified polyvinyl alcohol resin having a function of aligning said plurality of layers preferentially in one direction. The modified polyvinyl alcohol resin film stably provides a uniform alignment state with a larger tilt angle than a conventional alignment control film of polyimide or unmodified polyvinyl alcohol.
    Type: Grant
    Filed: March 17, 1987
    Date of Patent: April 11, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinjiro Okada, Kazuo Yoshinaga, Osamu Taniguchi, Hideyuki Kawagishi, Akira Tsuboyama, Yukio Hanyu, Masataka Yamashita, Kazuharu Katagiri
  • Patent number: 4818077
    Abstract: In a liquid crystal device wherein a bistable ferroelectric liquid crystal is sandwiched between display electrodes; a liquid crystal device and a driving method therefor characterized in that switching elements are disposed at respective intersection points between a plurality of scanning electrodes and a plurality of signal electrodes, and that at a juncture between said each switching element and one of said display electrodes, a control element is disposed by which when said switching element is off, an absolute value of a crest value of a voltage applied to said ferroelectric liquid crystal is held less than a threshold value (.vertline.V.sub.th .vertline.) of said ferroelectric liquid crystal.
    Type: Grant
    Filed: August 28, 1985
    Date of Patent: April 4, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Junichi Ohwada, Katsumi Kondo