Patents by Inventor Minhua Lu

Minhua Lu 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: 5883687
    Abstract: A liquid crystal (LC) cell having LC phase gratings is disclosed. The LC cell includes alternating strips of a first single domain LC material having a twist angle with a magnitude and a positive sign, and a second single domain LC material having a twist angle with the same magnitude and a negative sign. The magnitude of the twist angle is approximately from 45 to 70 degrees. The first and second LC materials are twisted nematic LC materials or ferro-electric LC materials. The liquid crystal phase gratings operate preferably in a normally-black condition with low operating voltages of below 3 V and high optical diffraction efficiencies. The LC cell is used in reflective or transmissive spatial light modulators of displays.
    Type: Grant
    Filed: April 2, 1997
    Date of Patent: March 16, 1999
    Assignee: International Business Machines Corporation
    Inventors: Minhua Lu, Kei-Hsiung Yang
  • Patent number: 5870164
    Abstract: A twisted nematic liquid crystal (TNLC) cell used in reflective spatial light modulators (SLMs) of displays is disclosed. The TNLC cell includes front and rear substrates, and a TNLC material having a thickness d and a left-handed or right-handed twist angle .phi.. The TNLC material is sandwiched between the front and rear substrates, and the twist angle .phi. is approximately from 46.degree. to 62.degree.. A direction of directors of the TNLC material located nearest the front substrate forms an initial angle .beta. with a direction of linearly polarized light incident thereon. The initial angle .beta. is approximately from -6.degree. to 60.degree.. A birefringence .DELTA.n of the TNLC material times the thickness d is between approximately 0.7.lambda. to 1.25.lambda., where .lambda. is a wavelength of light incident on the front substrate.
    Type: Grant
    Filed: June 20, 1997
    Date of Patent: February 9, 1999
    Assignee: International Business Machines Corporation
    Inventors: Minhua Lu, Robert Lee Melcher, James Lawrence Sanford, Kei-Hsiung Yang
  • Patent number: 5831710
    Abstract: A structural principle is described for control of the gap and the area around the periphery of a liquid crystal display by the formation of an insulating layer out of which, gap dimension maintaining posts and contaminant diffusion inhibiting segmented walls, remain after the display area is etched back out of the layer.
    Type: Grant
    Filed: February 6, 1997
    Date of Patent: November 3, 1998
    Assignee: International Business Machines Corporation
    Inventors: Evan G. Colgan, Minhua Lu, Robert Lee Melcher, James Lawrence Sanford, Kei-Hsiung Yang
  • 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: 5644330
    Abstract: A display device (10) having first and second substrates (12) and (30) and a layer of a PSCT or PFCT liquid crystal material disposed therebetween. The display is driven by an addressing scheme in which voltages are applied either in phase or out of phase in order to switch the liquid crystal material between stable states.
    Type: Grant
    Filed: August 22, 1995
    Date of Patent: July 1, 1997
    Assignee: Kent Displays, Inc.
    Inventors: Clive Catchpole, Haiji Yuan, Minhua Lu
  • Patent number: 5570216
    Abstract: A structurally stabilized bistable cholesteric display. The display has a back plate and a front plate with a liquid crystal material disposed therebetween. The liquid crystal material is homeotropically aligned at least at the substrate and is held in alignment by a securement matrix forming agent. The material is thermally annealed to align the helix axis of the liquid crystal molecules parallel to the substrates and a polymer may be used to secure the molecules in this position.
    Type: Grant
    Filed: April 14, 1995
    Date of Patent: October 29, 1996
    Assignee: Kent Display Systems, Inc.
    Inventors: Minhua Lu, Haiji Yuan
  • Patent number: 5493430
    Abstract: A display device (10) having first and second substrates (12) and (30) and a layer of a liquid crystal material having a periodic modulated structure, such as a PSCT or PFCT liquid crystal material disposed therebetween. A layer of a color imparting material (18) is disposed atop one surface of one substrate. The liquid crystal material is tailored or tuned to complementarily provide color to said display in connection with said layer of color imparting material.
    Type: Grant
    Filed: August 3, 1994
    Date of Patent: February 20, 1996
    Assignee: Kent Display Systems, L.P.
    Inventors: Minhua Lu, Haiji Yuan, Zvi Yaniv