Patents by Inventor Wei Keat Chai

Wei Keat Chai 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: 20200308025
    Abstract: A UVC disinfection system is described where incoming fluid, such as water, is directed onto a transparent window in a vertical disinfection chamber. The incoming water is directed downward by a channel at an acute angle (e.g., 10-20 degrees) with respect to a central axis of the disinfection chamber and impinges on the window at an angle almost perpendicular to the window surface. One or more UVC LEDs are optically coupled to the window. The water impinging on the window becomes agitated due to the severe redirection and interaction with water already in the chamber. This randomizes (mixes) the water in the area where there is the highest UVC power. The UVC LEDs direct light along the central axis of the cylindrical chamber for maximum exposure of the water to the UVC light. Disinfection efficiency is therefore increased.
    Type: Application
    Filed: March 25, 2019
    Publication date: October 1, 2020
    Inventors: Douglas A. Collins, Li Zhang, Wei Keat Chai, Faisal Sudradjat, Yitao Liao
  • Patent number: 8970989
    Abstract: In a disk drive suspension circuit, in order to improve stability of the stable pitch static attitude (PSA) over changes in humidity, the suspended portion of the flexible circuit and/or the gimbal support arm are modified to change their response(s) to humidity. Additional hygroscopic material is added to the circuit, and/or the polyimide insulating layer or the coverlayer are selectively removed, so that the net bend in the suspended portion of the circuit over humidity is reduced, ideally to a condition of zero or close to zero net bending. Hygroscopic material such as the material of the insulating layer may be added to the stainless steel gimbal support arm, so that in response to humidity it bends in the opposite direction as the suspended portion of the circuit.
    Type: Grant
    Filed: April 11, 2013
    Date of Patent: March 3, 2015
    Assignee: Magnecomp Corporation
    Inventors: Peter Hahn, Wei Keat Chai, Kuen Chee Ee
  • Patent number: 8654482
    Abstract: A dual stage actuator (DSA) suspension has a single microactuator such as a PZT element on one side of central longitudinal axis of the suspension, and a pseudo symmetry structure formed or affixed on the other side of the central longitudinal axis opposite the PZT. The pseudo symmetry structure has mass and stiffness that mirrors the PZT, thus keeping the suspension mechanically balanced and symmetric about the longitudinal axis for improved suspension performance especially in a shock environment. The pseudo symmetry structure can include a spring to keep the PZT under compression to prevent PZT failure, and/or a strain gauge for use by the head positioning servo-control system.
    Type: Grant
    Filed: August 1, 2013
    Date of Patent: February 18, 2014
    Assignee: Magnecomp Corporation
    Inventors: Peter Hahn, Wei Keat Chai, Kuen Chee Ee, Brett Holaway
  • Patent number: 8559138
    Abstract: A dual stage actuator (DSA) suspension has a single microactuator such as a PZT element on one side of central longitudinal axis of the suspension, and a pseudo symmetry structure formed or affixed on the other side of the central longitudinal axis opposite the PZT. The pseudo symmetry structure has mass and stiffness that mirrors the PZT, thus keeping the suspension mechanically balanced and symmetric about the longitudinal axis for improved suspension performance especially in a shock environment.
    Type: Grant
    Filed: June 22, 2012
    Date of Patent: October 15, 2013
    Assignee: Magnecomp Corporation
    Inventors: Peter Hahn, Wei Keat Chai, Kuen Chee Ee
  • Patent number: 8441761
    Abstract: In a disk drive suspension circuit, in order to improve stability of the stable pitch static attitude (PSA) over changes in humidity, the suspended portion of the flexible circuit and/or the gimbal support arm are modified to change their response(s) to humidity. In one embodiment, hygroscopic material such as the material of the insulating layer are added to the stainless steel gimbal support arm, so that in response to humidity it bends in the opposite direction as the suspended portion of the circuit. In another embodiment, additional hygroscopic material is added to the circuit, and/or the polyimide insulating layer or the coverlayer are selectively removed, so that the net bend in the suspended portion of the circuit over humidity is reduced, ideally to a condition of zero or close to zero net bending.
    Type: Grant
    Filed: January 3, 2011
    Date of Patent: May 14, 2013
    Assignee: Magnecomp Corporation
    Inventors: Peter Hahn, Wei Keat Chai, Kuen Chee Ee
  • Patent number: 8228642
    Abstract: A dual stage actuator (DSA) suspension has a single microactuator such as a PZT element on one side of central longitudinal axis of the suspension, and a pseudo symmetry structure formed or affixed on the other side of the central longitudinal axis opposite the PZT. The pseudo symmetry structure has mass and stiffness that mirrors the PZT, thus keeping the suspension mechanically balanced and symmetric about the longitudinal axis for improved suspension performance especially in a shock environment.
    Type: Grant
    Filed: February 16, 2010
    Date of Patent: July 24, 2012
    Assignee: Magnecomp Corporation
    Inventors: Peter Hahn, Wei Keat Chai, Kuen Chee Ee
  • Patent number: 8149545
    Abstract: A dual-stage actuator disk drive suspension load beam has a recessed cavity formed in it into which the microactuator motor is partially or completely placed. The cavity may be formed by partially etching the load beam during the same etching process that creates the load beam from a sheet of stainless steel material. The partially etched load beam having a cavity for the microactuator motor has the advantages of a lower profile, improved inertial balancing of the suspension, and increased sway resonant frequency.
    Type: Grant
    Filed: October 20, 2009
    Date of Patent: April 3, 2012
    Assignee: Magnecomp Corporation
    Inventors: Wei Keat Chai, Peter Hahn