Patents by Inventor Kei-Hsiung Yang

Kei-Hsiung Yang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5764314
    Abstract: A liquid crystal element, a packaging structure providing thermal and alignment control, a display device including the same, and methods of fabrication and assembly are provided. The liquid crystal element includes: a semiconductor wafer, having microcircuitry and an array of reflective pixels; a layer of electro-optical responsive liquid crystal medium, of uniform thickness, disposed on the reflective pixels; a transparent conductive layer positioned on the liquid crystal, being substantially parallel to the reflective layers, to ensure a uniform thickness of the liquid crystal; and an insulative transparent layer provided on the conductive layer. The liquid crystal element is laminated to an optically flat substrate to limit the out-of-plane distortions thereof. The structure formed by element and substrate are disposed in a substrate holder which is mounted to a wiring board, and coupled to voltage sources for actuating the liquid crystal.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: June 9, 1998
    Assignee: International Business Machines Corporation
    Inventors: Chandrasekhar Narayan, Evan Colgan, Kei-Hsiung Yang, Robert L. Melcher, Lawrence S. Mok, Leathen Shi, Thomas M. Cipolla
  • Patent number: 5764324
    Abstract: A reflective liquid crystal cell for AMLCDs is provided wherein the reflective electrode may be passivated with an insulating film such as silicon oxide. In addition, the liquid crystal cell of the present invention may include a conducting transparent electrode that has a work function substantially equal to the work function of the reflective electrode in the cell. The reflective electrode may include a transparent conductive layer such as ITO, or may include an integer number of film pairs, wherein the film pair comprises a first dielectric film having a low index of refraction and a second dielectric film having a high index of refraction.
    Type: Grant
    Filed: January 22, 1997
    Date of Patent: June 9, 1998
    Assignee: International Business Machines Corporation
    Inventors: Minhua Lu, Kei-Hsiung Yang
  • Patent number: 5721602
    Abstract: A liquid crystal element, a packaging structure providing thermal and alignment control, a display device including the same, and methods of fabrication and assembly are provided. The liquid crystal element includes: a semiconductor wafer, having microcircuitry and an array of reflective pixels; a layer of electro-optical responsive liquid crystal medium, of uniform thickness, disposed on the reflective pixels; a transparent conductive layer positioned on the liquid crystal, being substantially parallel to the reflective layers, to ensure a uniform thickness of the liquid crystal; and an insulative transparent layer provided on the conductive layer. The liquid crystal element is laminated to an optically flat substrate to limit the out-of-plane distortions thereof. The structure formed by element and substrate are disposed in a substrate holder which is mounted to a wiring board, and coupled to voltage sources for actuating the liquid crystal.
    Type: Grant
    Filed: October 11, 1995
    Date of Patent: February 24, 1998
    Assignee: International Business Machines Corporation
    Inventors: Chandrasekhar Narayan, Evan Colgan, Kei-Hsiung Yang, Robert L. Melcher, Lawrence S. Mok, Leathen Shi, Thomas M. Cipolla
  • Patent number: 4617646
    Abstract: A liquid crystal storage device includes a smectic phase liquid crystalline medium in spaced relationship with at least three separated electrodes, the first of which provides a ground plane and is in contact with the liquid crystal medium; a second electrode, spaced from the first electrode, is arranged in a mesh-like or finger electrode configuration, being likewise in contact with the liquid crystal medium; a third electrode is spaced by a dielectric medium from the second electrode, such third electrode being in either orthogonal or parallel relationship with the second electrode. Voltages are selectively applied to each of the second and third electrodes such that the stable state of the liquid crystalline layer is changed from the ordered (homeotropic) or clear state, to the disordered (focal conic) or dark state.
    Type: Grant
    Filed: June 29, 1984
    Date of Patent: October 14, 1986
    Assignee: International Business Machines Corporation
    Inventor: Kei-Hsiung Yang
  • Patent number: 4577930
    Abstract: A two-electrode nematic liquid crystal display (LCD) device with inherent storage effect is described. The described storage effect LCD device, which can properly operate without refresh circuitry, can be of either the homogeneous or twisted nematic type. In accordance with the invention, the liquid crystal material-to-substrate anisotropic surface anchoring force is set sufficiently weak by surface treatment techniques, to prevent the restoration of the device to its quiescent state once the device has been driven temporarily to its active state by a temporary increase in an applied electric field.
    Type: Grant
    Filed: May 24, 1982
    Date of Patent: March 25, 1986
    Assignee: International Business Machines Corporation
    Inventor: Kei-Hsiung Yang
  • Patent number: 4218619
    Abstract: A method and apparatus for ion-valve radiography allowing a multiplicity of copies to be made responsive to a single radiographic exposure. Radiation, differentially-absorbed by passage through an object to be studied, enters an exposure chamber having a foraminate film or mesh structure surrounded by a high pressure gas or radio-conductive liquid of a type which converts the impingent radiation into electrostatic charge. The chamber is bounded by a pair of electrodes establishing electric fields therein to cause a charge image of the object to form upon an insulating layer contained upon the mesh structure. After exposure, the charge-image-bearing member is moved to a printing chamber and a charge image is deposited upon an insulative material sheet by ion flow techniques, for subsequent development by xerographic techniques.
    Type: Grant
    Filed: September 15, 1978
    Date of Patent: August 19, 1980
    Assignee: General Electric Company
    Inventors: Kei-Hsiung Yang, Lothar A. Gruenke
  • Patent number: 4200790
    Abstract: A method and apparatus for ion-valve radiography, utilizing a high-pressure gaseous material for conversion of differentially-absorbed X-radiation into electrostatic charge images, utilizes a closed chamber and a charge-image-receiving mesh structure movable between an ion source and ion detection means, to provide direct charge readout without requiring opening of the imaging chamber.
    Type: Grant
    Filed: December 22, 1978
    Date of Patent: April 29, 1980
    Assignee: General Electric Company
    Inventors: Kei-Hsiung Yang, Jack D. Kingsley
  • Patent number: 4196350
    Abstract: Improved apparatus for photocontrolled ion-flow electron radiography utilizes a selectively movable bonded phosphor plaque to allow removal of corona discharge means, utilized to precharge the selenium mesh before X-ray exposure, while increasing the quantum efficiency of the photoconductor.
    Type: Grant
    Filed: January 2, 1979
    Date of Patent: April 1, 1980
    Assignee: General Electric Company
    Inventor: Kei-Hsiung Yang
  • Patent number: 4156140
    Abstract: Electrostatic x-ray imaging apparatus of the type having a gas-filled chamber bounded by a photocathode and a charge-receiving sheet anode has a control mesh positioned in the gas-filled gap and maintained at a positive voltage with respect to the cathode to facilitate high avalanche amplification and has a voltage between the mesh member and the anode chosen in the plateau region of the x-ray photocurrent versus voltage curve, to achieve a nearly constant efficiency of charge collection at the anode, independent of accumulation of charge thereat.
    Type: Grant
    Filed: September 19, 1977
    Date of Patent: May 22, 1979
    Assignee: General Electric Company
    Inventors: James M. Lafferty, Kei-Hsiung Yang
  • Patent number: 4150315
    Abstract: Apparatus for X-ray radiography includes a conductive cathode, receiving X-radiation differentially attenuated by passage through an object to be studied, and a conductive anode spaced from the cathode and bearing a sheet of insulative material upon which a charge image of the object is to be formed; and a structured photocathode extending from the cathode towards the anode. The photocathode, formed of cesium iodide and the like, is of relative great thickness and surface area to have large X-ray quantum absorption and photoelectron emission, whereby a lower exposure dosage of X-radiation is required for a radiographic exposure. A plurality of different photocathode structures are disclosed.
    Type: Grant
    Filed: May 8, 1978
    Date of Patent: April 17, 1979
    Assignee: General Electric Company
    Inventor: Kei-Hsiung Yang
  • Patent number: 4147948
    Abstract: Apparatus for X-ray radiography includes a conductive cathode, receiving X-radiation differentially attenuated by passage through an object to be studied, and a conductive anode spaced from the cathode and bearing a sheet of insulative material upon which a charge image of the object is to be formed; and a structured photocathode extending from the cathode towards the anode. The photocathode, formed of cesium iodide and the like, is of relative great thickness and surface area to have large X-ray quantum absorption and photoelectron emission, whereby a lower exposure dosage of X-radiation is required for a radiographic exposure. A plurality of different photocathode structures are disclosed.
    Type: Grant
    Filed: May 8, 1978
    Date of Patent: April 3, 1979
    Assignee: General Electric Company
    Inventor: Kei-Hsiung Yang
  • Patent number: 4147949
    Abstract: Apparatus for X-ray radiography includes a conductive cathode, receiving X-radiation differentially attenuated by passage through an object to be studied, and a conductive anode spaced from the cathode and bearing a sheet of insulative material upon which a charge image of the object is to be formed; and a structured photocathode extending from the cathode towards the anode. The photocathode, formed of cesium iodide and the like, is of relative great thickness and surface area to have large X-ray quantum absorption and photoelectron emission, whereby a lower exposure dosage of X-radiation is required for a radiographic exposure. A plurality of different photocathode structures are disclosed.
    Type: Grant
    Filed: May 8, 1978
    Date of Patent: April 3, 1979
    Assignee: General Electric Company
    Inventor: Kei-Hsiung Yang
  • Patent number: 4132962
    Abstract: A tunable laser system emitting coherent radiation selectively variable over the range of wavelengths from about 2760 A to about 3220 A utilizes a crystal, composed of fluoride of at least a Column IIIb metal doped with trivalent ions of cerium and pumped with high average power pulses. The crystal is emplaced in an optical cavity having means such as diffraction grating, etalon, or optically-tunable prism, to vary the coherent emission wavelength.
    Type: Grant
    Filed: August 10, 1977
    Date of Patent: January 2, 1979
    Assignee: General Electric Company
    Inventors: Kei-Hsiung Yang, John A. DeLuca
  • Patent number: 4129779
    Abstract: Photocontrolled ion-flow electron radiography apparatus has a multi-layered mesh structure, comprised of a conductive apertured sheet supporting an insulating layer, overlayed with a conductive screen and a top-most layer of photoconductive material, to control an ion stream responsive to a charge image formed in the photoconductive layer responsive to a pattern of x-rays differentially-absorbed by an object to be analyzed.
    Type: Grant
    Filed: September 19, 1977
    Date of Patent: December 12, 1978
    Assignee: General Electric Company
    Inventors: Jack D. Kingsley, Kei-Hsiung Yang
  • Patent number: 4117365
    Abstract: Apparatus for X-ray radiography includes a conductive cathode, receiving X-radiation differentially attenuated by passage through an object to be studied, and a conductive anode spaced from the cathode and bearing a sheet of insulative material upon which a charge image of the object is to be formed; and a structured photocathode extending from the cathode towards the anode. The photocathode, formed of cesium iodide and the like, is of relative great thickness and surface area to have large X-ray quantum absorption and photoelectron emission, whereby a lower exposure dosage of X-radiation is required for a radiographic exposure. A plurality of different photocathode structures are disclosed.
    Type: Grant
    Filed: January 14, 1977
    Date of Patent: September 26, 1978
    Assignee: General Electric Company
    Inventor: Kei-Hsiung Yang
  • Patent number: 4085327
    Abstract: An improved direct charge readout electron radiography apparatus of the type having an upper electrode receiving differentially-absorbed X-radiation, a lower electrode including a plurality of parallel transparent, conductive strips overlaid with a layer of photoconductive material; and means for scanning a beam of light through the transparent strips and into the overlying photoconductive material layer for selectively transferring charge patterns induced therein responsive to the pattern of differentially-absorbed X-radiation, utilizes at least one lead means strip, positioned substantially transverse to, and spaced from the ends of, the plurality of conductive strips. The transverse lead means strip is connected to sequential ones of the parallel strips responsive to illumination of the photoconductive material in the area between the transverse strip and an adjacent end of each sequential parallel strip.
    Type: Grant
    Filed: January 14, 1977
    Date of Patent: April 18, 1978
    Assignee: General Electric Company
    Inventors: Robert K. Swank, Kei-Hsiung Yang
  • Patent number: 4083018
    Abstract: A tunable laser system emitting coherent radiation selectively variable over the range of wavelengths from about 1650 A to about 3300 A utilizes a crystal, composed of a fluoride of at least a Column IIIb metal doped with at least one trivalent ion of a lanthanide series element, and pumped with high average power pulses. The crystal is emplaced in an optical cavity having means, such as a diffraction grating, etalon, or optically-tunable prism, to vary the coherent emission wavelength.
    Type: Grant
    Filed: July 6, 1976
    Date of Patent: April 4, 1978
    Assignee: General Electric Company
    Inventors: Kei-Hsiung Yang, John A. De Luca
  • Patent number: 4064439
    Abstract: A method and apparatus for photocontrolled ion-flow electron radiography utilizes a selectably movable phosphor plaque for controlling the selective discharge of a precharged photoconductive layer responsive to differential x-ray absorption in an object to be analyzed, to generate a charge image differentially controlling the deposition of ions upon a film for xerographic recording.
    Type: Grant
    Filed: August 20, 1976
    Date of Patent: December 20, 1977
    Assignee: General Electric Company
    Inventor: Kei-Hsiung Yang
  • Patent number: 4039830
    Abstract: An electrostatic X-ray image recording device having a pair of spaced electrodes with a gas-filled gap therebetween, and including discrimination means, having a conductive mesh supporting a photocathodic material, positioned in the gas-filled gap between a first electrode having a layer of ultraviolet-emitting fluorescent material and a second electrode having a plastic sheet adjacent thereto for receiving photoelectrons emitted by the photocathodic material and accelerated to the second electrode by an applied field. The photoconductor-mesh element discriminates against fast electrons, produced by direct impingement of X-rays upon the photocathode to substantially reduce secondary electron production and amplification, thereby increasing both the signal-to-noise and contrast ratios. The electrostatic image formed on the plastic sheet is developed by zerographic techniques after exposure.
    Type: Grant
    Filed: August 13, 1976
    Date of Patent: August 2, 1977
    Assignee: General Electric Company
    Inventor: Kei-Hsiung Yang