Patents by Inventor Hoi-Sing Kwok

Hoi-Sing Kwok 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).

  • Publication number: 20070212855
    Abstract: The invention provides a method for forming thin film transistors including a polycrystalline semiconducting film. The method comprises depositing a first layer of amorphous semiconducting thin film on to a substrate; depositing a second layer of thin film on to the first layer of amorphous semiconducting thin film; patterning the second layer or thin film so that the first layer of amorphous semiconducting thin film is exposed at selected locations; exposing the first and second layers of thin film to a nickel containing compound in either a solution or a vapor phase; removing the second layer of thin film; and annealing the first layer of amorphous semiconducting thin film at an elevated temperature so the first layer of amorphous semiconducting thin film converts into a polycrystalline semiconducting thin film.
    Type: Application
    Filed: March 9, 2007
    Publication date: September 13, 2007
    Inventors: Hoi Sing Kwok, Man Wong, Zhiguo Meng, Shuyun Zhao, Chunya Wu
  • Publication number: 20070159582
    Abstract: This invention pertains to the design and construction of retardation films (or plates) with any targeted dispersive property, including those with no wavelength dependence for the entire visible range. In particular, this invention deals with specific design of films with broadband (achromatic) quarterwave and halfwave retardation.
    Type: Application
    Filed: January 11, 2007
    Publication date: July 12, 2007
    Inventors: Hoi-Sing Kwok, Xing-Jie Yu
  • Patent number: 7236219
    Abstract: The present invention relates to color liquid crystal displays without the use of color filters. By carefully choosing the design parameters of a liquid crystal display, it is possible to obtain vivid colors from the display as a function of the operating voltage.
    Type: Grant
    Filed: November 28, 2003
    Date of Patent: June 26, 2007
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Hoi-Sing Kwok, Xing-Jie Yu
  • Publication number: 20070139595
    Abstract: The invention provides a bistable twisted nematic liquid crystal display, comprising a first substrate having thereon a first conductive layer and a first alignment layer; a second substrate having thereon a second conductive layer and a second alignment layer; a liquid crystal layer in the first and second alignment layers; an alignment layer on each of the substrates, the alignment layer imparting a preferred direction for liquid crystal molecules near the alignment layer, and possessing different azimuthal and polar anchoring energies when used to align a liquid crystal layer: the alignment layers being rubbed in such a way to give a stable twist angle of the liquid crystal of ? where ? can be any value in between ?45° to +45°; and wherein the d/p ratio of the liquid crystal layer is between the values of 0.15+0.5?/? and 0.35+0.5?/?.
    Type: Application
    Filed: November 24, 2006
    Publication date: June 21, 2007
    Inventors: Hoi-Sing Kwok, Fion Sze Yeung, Yuet Li
  • Publication number: 20070114522
    Abstract: An organic light-emitting diode display which can display independent images on both sides is described. This display can be driven with passive matrix or active matrix schemes. The invention combines a unique stacked organic diode structure and special driving schemes involving time-sequential reversed fields.
    Type: Application
    Filed: October 31, 2006
    Publication date: May 24, 2007
    Inventors: Hoi-Sing Kwok, Man Wong, Jiaxin Sun, Zhiguo Meng, Xiuling Zhu
  • Publication number: 20070024782
    Abstract: This invention provides a bistable liquid crystal device. The bistable liquid crystal device includes a first substrate having thereon a first conductive layer and a first alignment layer, a second substrate having thereon a second conductive layer and a second alignment layer; and a liquid crystal layer sandwiched between the first and second alignment layers. The first alignment layer induces a first pretilt angle ?1 in the range of 20°-65° between the liquid crystal layer in contact with the first alignment layer. The second alignment layer induces a second pretilt angle ?2 in the range of 20°-65° between the liquid crystal layer in contact with the second alignment layer. The liquid crystal layer is capable of maintaining a stable bend state or a stable splay state at zero bias voltage and is switchable between the stable bend state and the stable splay state when a switching energy is applied in operation to the liquid crystal layer.
    Type: Application
    Filed: October 18, 2004
    Publication date: February 1, 2007
    Inventors: Hoi-Sing Kwok, Xing Yu
  • Publication number: 20060263957
    Abstract: Crystallization-inducing metal elements are introduced onto an amorphous silicon thin film. A first, low-temperature, heat-treatment induces nucleation of metal-induced crystallization (MIC), resulting in the formation of small polycrystalline silicon “islands”. A metal-gettering layer is formed on the resulting partially crystallized thin film. A second, low-temperature, heat-treatment completes the MIC process, whilst gettering metal elements from the partially crystallized thin film. The process results in the desired polycrystalline silicon thin film.
    Type: Application
    Filed: April 27, 2006
    Publication date: November 23, 2006
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Man Wong, Hoi-Sing Kwok, Zhiguo Meng, Dongli Zhang, Xuejie Shi
  • Patent number: 7133211
    Abstract: Optical system designs for projectors using flat light sources are disclosed. These projectors make use of imagers that manipulate the transmission or reflectance of light through electronically controlled pixels. The optical systems of the invention employ a rectangular flat light source that is matched to the aspect ratio of the imager itself, thus enabling very efficient use of light. Several flat light sources are possible for this projection system, including flat fluorescent lights and field emission light sources. Collimation of these light sources is an option. Polarization conversion means is also disclosed for such flat light sources, so that the light output is almost totally linearly polarized. Such projection systems can be very compact.
    Type: Grant
    Filed: April 2, 2004
    Date of Patent: November 7, 2006
    Assignee: Integrated Microdisplays Limited
    Inventor: Hoi-Sing Kwok
  • Patent number: 7070712
    Abstract: There is disclosed a liquid crystalline polyacetylene having a repeat structure of the formula where spa is a spacer group and mes is a mesogenic substituent.
    Type: Grant
    Filed: April 12, 2005
    Date of Patent: July 4, 2006
    Assignee: The Hong Kong University of Science & Technology
    Inventors: Ben Zhong Tang, Wing Yip Lam, Xiangxing Kong, Hoi Sing Kwok
  • Patent number: 7070913
    Abstract: The present invention provides a method of forming a polarizing material comprising exposing a layer of dichroic material to activating light illumination to provide an ordered structure with a distinguished absorption axis and thus photo-induce polarization, and fixing the induced polarization by polymerisation of the dichroic layer. The present invention also provides novel polarizing materials formed thereby. By selectively exposing regions of the dichroic material to differing activating radiation, different regions with different polarization axes can be created. The polarizing material can also be provided with a coating or coatings to alter the spectral response, and a stack formed of a plurality if dichroic layers may be provided.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: July 4, 2006
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Vladimir Markovich Kozenkov, Wing Chiu Yip, Vladimir Grigorievich Chigrinov, Elena Karlovna Prudnikova, Hoi Sing Kwok
  • Publication number: 20060091378
    Abstract: A class of luminescent gold(III) compounds with a tridentate ligand and at least one strong ?-donating group having the chemical structure represented by the general formula (I): wherein R1-R4 each independently represent the group containing hydrogen, halogen, alkynyl, substituted alkynyl, alkyl, substituted alkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxyl, substituted alkoxyl, amino, substituted amino, cyano, nitro, alkylcarbonyl, alkoxycarbonyl, arylcarbonyl, aryloxycarbonyl, mono- or dialkylaminocarbonyl, alkylcarbonyloxy, arylcarbonyloxy, aryloxy, alkoxycarbonyl, aryloxycarbonyloxy group, and the like; X, Y and Z each independently represent a heteroatom or a carbon; represents an aromatic or heterocyclic 5- or 6-membered ring; ? and ? each independently represent a bridge for an aromatic or heterocyclic 5- or 6-membered ring or represent a break for non-cyclic moiety; C—X, C—Y and C-Z each independently represent a single bond or double bond; n represents a zero or an
    Type: Application
    Filed: October 29, 2004
    Publication date: May 4, 2006
    Inventors: Vivian Yam, Man-Chung Wong, Hoi-Sing Kwok, Xiuling Zhu
  • Publication number: 20060055650
    Abstract: This invention provides a method and apparatus for driving bistable cholesteric liquid crystal displays. The method and apparatus provided a display in which all the pixels are initially driven to the P state. Selected pixels for the display are then driven to the FC state to provide the desired message. The state of the pixels is then maintained for a viewing period prior to any resetting of the display to the P state. The switching from the P state to the FC state allows fast addressing times and lower voltages to be used in driving the display.
    Type: Application
    Filed: November 7, 2005
    Publication date: March 16, 2006
    Inventors: Hoi-Sing Kwok, Fei-Hong Yu, Qing-Cheng Li, Wing-Chiu Yip
  • Publication number: 20050260426
    Abstract: The present invention relates to a liquid crystal alignment layer used in a liquid crystal cell, which is capable of providing high pretilt angles.
    Type: Application
    Filed: October 5, 2004
    Publication date: November 24, 2005
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Hoi-Sing Kwok, Fion Yeung, Fengchao Xie, Ophelia Tsui, Ping Sheng
  • Publication number: 20050225882
    Abstract: Optical system designs for projectors using flat light sources are disclosed. These projectors make use of imagers that manipulate the transmission or reflectance of light through electronically controlled pixels. The optical systems of the invention employ a rectangular flat light source that is matched to the aspect ratio of the imager itself, thus enabling very efficient use of light. Several flat light sources are possible for this projection system, including flat fluorescent lights and field emission light sources. Collimation of these light sources is an option. Polarization conversion means is also disclosed for such flat light sources, so that the light output is almost totally linearly polarized. Such projection systems can be very compact.
    Type: Application
    Filed: April 2, 2004
    Publication date: October 13, 2005
    Applicant: SHENZHEN DICHENG TECHNOLOGY COMPANY LIMITED
    Inventor: Hoi-Sing Kwok
  • Patent number: 6953716
    Abstract: A metal induced lateral crystallization (MILC) poly-silicon material is produced by depositing a metal in a predefined pattern on amorphous silicon, and heat treating the silicon at a first temperature to form a MILC poly-Si material. The MILC poly-Si material is further heat treated at a second temperature higher than the first temperature to induce recrystallization. The second high temperature recrystallization step significantly enhances the material structure, and in particular the grain structure, of the poly-Si material with substantial benefits to the performance of semiconductor devices made therefrom.
    Type: Grant
    Filed: December 22, 2003
    Date of Patent: October 11, 2005
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Man Wong, Hoi Sing Kwok, Zhiguo Meng, Mingxiang Wang
  • Publication number: 20050218810
    Abstract: Disclosed here is an efficient flat light source based on UV light excited photoluminescence of phosphors. An electrical discharge is confined to be substantially planar by a glass enclosure. This electrical discharge produces ultraviolet photons. These UV photons in turn excite phosphors to produce visible light with great efficiency and high intensity. In this invention, light is taken out of the light source from one side only. A UV light recycling means is also provided. Means for collimation of this light source is disclosed for projection display applications. Polarization conversion means is also described for such flat light sources, so that the light output is almost totally linearly polarized.
    Type: Application
    Filed: April 2, 2004
    Publication date: October 6, 2005
    Applicant: SHENZHEN DICHENG TECHNOLOGY COMPANY LIMITED
    Inventors: Hoi-Sing Kwok, Yi Song
  • Patent number: 6919947
    Abstract: The present invention relates to color liquid crystal displays without the use of color filters. By using vertically aligned liquid crystal display cells, it is possible to obtain vivid colors from the display as a function of the operating voltage, with a bright background that can be gray or colored.
    Type: Grant
    Filed: November 28, 2003
    Date of Patent: July 19, 2005
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Hoi-Sing Kwok, Xing-Jie Yu
  • Publication number: 20050117091
    Abstract: The present invention relates to color liquid crystal displays without the use of color filters. By carefully choosing the design parameters of a liquid crystal display, it is possible to obtain vivid colors from the display as a function of the operating voltage.
    Type: Application
    Filed: November 28, 2003
    Publication date: June 2, 2005
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Hoi-Sing Kwok, Xing-Jie Yu
  • Publication number: 20050117101
    Abstract: The present invention relates to color liquid crystal displays without the use of color filters. By using vertically aligned liquid crystal display cells, it is possible to obtain vivid colors from the display as a function of the operating voltage, with a bright background that can be gray or colored.
    Type: Application
    Filed: November 28, 2003
    Publication date: June 2, 2005
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Hoi-Sing Kwok, Xing-Jie Yu
  • Publication number: 20050024307
    Abstract: This invention provides a method and apparatus for driving bistable cholesteric liquid crystal displays. The method and apparatus provided a display in which all the pixels are initially driven to the P state. Selected pixels for the display are then driven to the FC state to provide the desired message. The state of the pixels is then maintained for a viewing period prior to any resetting of the display to the P state. The switching from the P state to the FC state allows faster addressing times and lower voltages to be used in driving the display.
    Type: Application
    Filed: June 30, 2004
    Publication date: February 3, 2005
    Applicant: The Hong Kong University of Science & Technology
    Inventors: Hoi-Sing Kwok, Fei-Hong Yu, Qing-Cheng Li, Wing-Chiu Yip