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: 20110012124
    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 of 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: July 22, 2010
    Publication date: January 20, 2011
    Inventors: Hoi Sing Kwok, Man Wong, Zhiguo Meng, Shuyun Zhao, Chunya Wu
  • Patent number: 7790580
    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 of 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: Grant
    Filed: March 9, 2007
    Date of Patent: September 7, 2010
    Assignee: Hong Kong University of Science and Technology
    Inventors: Hoi Sing Kwok, Man Wong, Zhiguo Meng, Shuyun Zhao, Chunya Wu
  • Publication number: 20100171546
    Abstract: A low temperature polycrystalline silicon device and techniques to manufacture thereof with excellent performance. Employing doped poly-Si lines which we called a bridged-grain structure (BG), the intrinsic or lightly doped channel is separated into multiple regions. A single gate covering the entire active channel including the doped lines is still used to control the current flow. Using this BG poly-Si as an active layer and making sure the TFT is designed so that the current flows perpendicularly to the parallel lines of grains, grain boundary effects can be reduced. Reliability, uniformity and the electrical performance of the BG poly-Si TFT are significantly improved compared with the conventional low temperature poly-Si TFT.
    Type: Application
    Filed: February 4, 2008
    Publication date: July 8, 2010
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Hoi Sing Kwok, Man Wong, Zhiguo Meng, Shuyun Zhao
  • Patent number: 7696971
    Abstract: The invention provides a method for controlling the grey-scale modulation of a reflective bistable cholesteric display by applying selected sequences of high and low pulses to modulate the cholesteric domain size and helical axis orientation. Non-mesogenic dopants may also be added to reduce the drive voltage.
    Type: Grant
    Filed: May 10, 2002
    Date of Patent: April 13, 2010
    Assignees: The Hong Kong University of Science and Technology
    Inventors: Wing Chiu Yip, Hoi Sing Kwok, Cheryl Sun
  • Publication number: 20100071760
    Abstract: A solar cell photovoltaic device using ultrathin films of polycrystalline silicon and deep uneven surface structures is disclosed. According to one embodiment, the uneven structures include one or more pits having a depth of at least 10 microns. According to another embodiment, the uneven structures include one or more cones or columns having a height or at least 10 microns. Because the unevenness of the structures, the photovoltaic device is able to use a very thin layer of polycrystalline silicon to effectively trap and absorb light.
    Type: Application
    Filed: May 7, 2009
    Publication date: March 25, 2010
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Hoi Sing KWOK, Zhiguo MENG, Man WONG
  • Patent number: 7652136
    Abstract: The present invention provides a diarylaminofluorene chromophore compound having the following structure: wherein: M is a metal atom of Ir, Pt; R is H, CH3, OCH3, or F; A is none or six-member carbocyclic aromatic ring system; 0?m?3 0?n?1. The invention also provides high-efficiency organic light-emitting devices fabricated using these compounds.
    Type: Grant
    Filed: September 12, 2006
    Date of Patent: January 26, 2010
    Assignees: The Hong Kong University of Science and Technology, Hong Kong Baptist University
    Inventors: Hoi-Sing Kwok, Wai-Yeung Wong, Xiao-Ming Yu, Gui-Jiang Zhou
  • Publication number: 20090279032
    Abstract: We disclose a new method of preparing liquid crystal alignment layers that can produce controllable pretilt angles from near 0 to near 90°. It is based on the stacking of two alignment materials sequentially, with the first one being continuous and the second one being discontinuous leaving part of the first layer exposed.
    Type: Application
    Filed: May 6, 2009
    Publication date: November 12, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Hoi Sing KWOK, Yuet Wing LI, Chung Yung LEE
  • Patent number: 7572912
    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 i
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: August 11, 2009
    Assignee: University of Hong Kong
    Inventors: Vivian Wing-Wah Yam, Man-Chung Wong, Hoi-Sing Kwok, Xiuling Zhu
  • Patent number: 7557884
    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: Grant
    Filed: October 18, 2004
    Date of Patent: July 7, 2009
    Assignee: Hong Kong University of Science and Technology
    Inventors: Hoi-Sing Kwok, Xing Jie Yu
  • Patent number: 7551252
    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: Grant
    Filed: November 24, 2006
    Date of Patent: June 23, 2009
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Hoi-Sing Kwok, Fion Sze Yan Yeung, Yuet Wing Li
  • Publication number: 20090147187
    Abstract: Pixels of an LCD are divided into two sub-pixels, one for a reflective mode and one for a transmittive mode. The cell gaps of both sub-pixels are the same, improving fabrication ease. A novel photoalignment technique is used together with a shadow mask in an embodiment of the invention. Double exposure of the alignment layer with different orientations produces different alignment directions, thereby achieving the different LCD modes for the sub-pixels.
    Type: Application
    Filed: December 10, 2008
    Publication date: June 11, 2009
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Hoi Sing KWOK, Vladimir Grigorievich Chigrinov
  • Publication number: 20090134790
    Abstract: Metal induced polycrystallized silicon is used as the anode in a light emitting device, such as an OLED or AMOLED. The polycrystallized silicon is sufficiently non-absorptive, transparent and made sufficiently conductive for this purpose. A thin film transistor can be formed onto the polycrystallized silicon anode, with the silicon anode acting as the drain of the thin film transistor, thereby simplifying production.
    Type: Application
    Filed: December 19, 2008
    Publication date: May 28, 2009
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Hoi Sing Kwok, Man Wong, Zhiguo Meng, Jiaxin Sun, Xiuling Zhu
  • Publication number: 20080218469
    Abstract: Methods and systems for displaying videos with high contrast using fast transient response of liquid crystal materials are disclosed. The system comprises a liquid crystal material treated with a chiral dopant, which is aligned between two substrates with conductive layer on each substrate. The system can be operated in an active or passive matrix mode display. The active matrix display can be a thin film transistor (TFT) or MOS transistor, whereas no transistors are used for the passive matrix mode display. A full color display, with high contrast, can be achieved by illuminating the transient liquid crystal material with a pulsed backlight.
    Type: Application
    Filed: December 31, 2007
    Publication date: September 11, 2008
    Applicant: Hong Kong University of Science and Technology
    Inventors: Hoi Sing Kwok, Yuet Wing Li
  • Publication number: 20080204620
    Abstract: The construction of electrodes for liquid-crystal displays using larger grain lower absorption (LGLA) poly-Si showing an absorptivity below 20% in the visible light region is described. Integration in the manufacturing of substrates for active-matrix LCDs is shown. Source, drain and channel region (108b, 108c, 108d) of the TFTs as well as the pixel-electrode (108e) are formed conjointly in a single poly-Si layer.
    Type: Application
    Filed: May 21, 2005
    Publication date: August 28, 2008
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Zhiguo Meng, Man Wong, Hoi Sing Kwok
  • Publication number: 20080203394
    Abstract: The present invention provides a method of an active-matrix thin film transistor array, comprising of two levels of metallic interconnections formed from one layer of metallic conductor; and thin-film transistors with source, drain and gate electrodes either fully or partially replaced with metal, and wherein the pixel electrodes are polycrystalline silicon.
    Type: Application
    Filed: November 24, 2006
    Publication date: August 28, 2008
    Inventors: Hoi-Sing Kwok, Man Wong, Zhiguo Meng, Dongli Zhang, Jiaxin Sun, Xiuling Zhu
  • Patent number: 7402947
    Abstract: An organic light emitting diode consisting of multiple organic layers, disposed between a transparent conducting anode and metallic cathode. The anode is provided with a metal fluoride layer to enhance the overall performance of the device, including higher power efficiency, lower voltage threshold and improved device operation stability.
    Type: Grant
    Filed: September 7, 2005
    Date of Patent: July 22, 2008
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Hoi Sing Kwok, Man Wong, Hua-Jun Peng, Shuang Xie
  • Patent number: 7381507
    Abstract: This invention relates to methods for preparing photo-patterned mono- or polychromatic, polarizing films. The polarizer can be pixelated into a number of small regions wherein some of the regions have one orientation of the principal neutral or color absorbing axis; and some other of the said regions have another orientation of the principal neutral or color absorbing axis. The axis orientation is determined by the polarization vector of actinic radiation and the multi-axes orientation is possible by a separated masked exposure. This polarizer can be placed on the interior substrate surface of the LCD cell.
    Type: Grant
    Filed: July 10, 2003
    Date of Patent: June 3, 2008
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Hoi-Sing Kwok, Wing-Chiu Yip, Vladimir Chigrinov, Vladimir Kozenkov
  • Patent number: 7381600
    Abstract: The invention provides a method of forming polycrystalline silicon comprising the steps of: forming a layer of amorphous silicon, forming a layer of metal or metal-containing compound on the layer of amorphous silicon, annealing the layer of amorphous silicon and said layer of metal to form a polycrystalline silicon layer, and irradiating the polycrystalline silicon layer with two different harmonics of a pulsed laser. The pulsed laser is preferably a solid-state laser such as a Nd-Yag laser. One harmonic is chosen such that it is preferentially absorbed by defects in the polycrystalline silicon layer, the other harmonic is absorbed by the bulk polycrystalline silicon.
    Type: Grant
    Filed: December 1, 2005
    Date of Patent: June 3, 2008
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Man Wong, Hoi Sing Kwok, Zhiguo Meng
  • Publication number: 20080091021
    Abstract: The present invention provides a diarylaminofluorene chromophore compound having the following structure: wherein: M is a metal atom of Ir, Pt; R is H or any substituent such as CH3, OCH3, F; A is none or six-member aromatic ring system; m is at least 1; n is at least zero. The invention also provides high-efficiency organic light-emitting devices fabricated using these compounds.
    Type: Application
    Filed: September 12, 2006
    Publication date: April 17, 2008
    Inventors: Hoi-Sing Kwok, Wai-Yeung Wong, Xiao-Ming Yu, Gui-Jiang Zhou
  • Publication number: 20070254220
    Abstract: An azo compound of the present invention is represented by the general formula (1): (wherein, R1 and R2 each independently represents a hydroxy group, or a polymerizable functional group selected from the group consisting of a (meth)acryloyl group, a (meth)acryloyloxy group, a (meth)acrylamide group, a vinyl group, a vinyloxy group, and a maleimide group; X1 represents single bond when R1 is a hydroxy group and represents a linking group represented by -(A1-B1)m- when R1 is a polymerizable functional group; X2 represents a single bond when R2 is a hydroxy group and represents a linking group represented by -(A2-B2)n- when R2 is a polymerizable functional group; R3 and R4 each independently represents —OR7, a hydroxyalkyl group having 1 to 4 carbon atoms, or —CONR8R9; and R5 and R6 each independently represents a carboxy group, a sulfo group, a nitro group, amino group, or a hydroxy group).
    Type: Application
    Filed: June 28, 2005
    Publication date: November 1, 2007
    Applicants: DAINIPPON INK AND CHEMICALS, INC., HONG KONG UNIVERSITY OF SCIENCE & TECHNOLOGY
    Inventors: Hitoshi Kondo, Yasuhiro Kuwana, Hirokazu Takada, Vladimir Chigrinov, Hoi-Sing Kwok