Patents by Inventor Kai Yao

Kai Yao 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: 8102165
    Abstract: A power factor correction (PFC) circuit includes an inductor, a diode, a storage capacitor, a switch and a control unit. The input power has a voltage fluctuation V1. The storage component absorbs a first voltage fluctuation and a switch regulation circuit absorbs a second voltage fluctuation V2. Thus output voltage from the PFC circuit is not a conventional constant voltage but a voltage of a great ripple. The PFC circuit further has a harmonic regulation unit. The harmonic regulation unit generates a voltage signal containing 3rd harmonic. The control unit receives a feedback signal and the voltage signal containing 3rd harmonic to generate a reference to the inductor current. Therefore, the inductor current contains 3rd harmonic. Thus power fluctuation absorbed and released by the capacitor is smaller. As a result energy storage capacitance can be reduced significantly.
    Type: Grant
    Filed: July 1, 2009
    Date of Patent: January 24, 2012
    Assignees: FSP Technology Inc., Nanjing University of Aeronautics and Astronautics
    Inventors: Linlin Gu, Ming Xu, Xinbo Ruan, Kai Yao
  • Patent number: 8004861
    Abstract: The present invention discloses a parameter configuration method for elements of a PFC function converter. The converter has a PFC circuit modulating an input power into a DC modulated power and a transformer transforming the DC modulated power into an output power. The method of the present invention comprises a storage capacitor configuration procedure, a storage inductor configuration procedure and a verification procedure. The storage capacitor configuration procedure predetermines a test voltage and a rated bus voltage lower than the test voltage, determines a parameter of the storage capacitor according to the test voltage and uses the storage capacitor to supply the rated bus voltage. The storage inductor configuration procedure determines an inductance of a storage inductor to match the storage inductor and the primary coil of the transformer work in a discontinuous current mode. The verification procedure verifies whether the power factor of the converter exceeds 0.9.
    Type: Grant
    Filed: April 16, 2009
    Date of Patent: August 23, 2011
    Assignee: FSP Technology Inc.
    Inventors: Ming Xu, Bo Zhang, Kai Yao, Qiaoliang Chen
  • Publication number: 20110037414
    Abstract: A driving apparatus is provided and configured to suit driving at least a string of light emitting diodes (LEDs). The driving apparatus includes a flyback power factor correction (PFC) converter, a harmonics-filtering unit and a control unit. The flyback PFC converter works in an operation mode according to a pulse-width modulation (PWM) signal and receives an AC power so as to convert the AC power into a pulsating current. The harmonics-filtering unit is coupled to the flyback PFC converter and the string of LEDs, for receiving the pulsating current and filtering out the high-frequency harmonic components in the pulsating current so as to drive the string of LEDs. The control unit is coupled to the flyback PFC converter and the harmonics-filtering unit, for producing the PWM signal according to the AC power and the pulsating current, and reducing the peak-to-average ratio (PAR) of the pulsating current.
    Type: Application
    Filed: January 12, 2010
    Publication date: February 17, 2011
    Applicants: NANJING UNIVERSITY OF AERONAUTICS AND ASTRONAUTICS, FSP TECHNOLOGY INC.
    Inventors: Beibei Wang, Xinbo Ruan, Ming Xu, Kai Yao
  • Publication number: 20100265745
    Abstract: The present invention discloses a parameter configuration method for elements of a PFC function converter. The converter has a PFC circuit modulating an input power into a DC modulated power and a transformer transforming the DC modulated power into an output power. The method of the present invention comprises a storage capacitor configuration procedure, a storage inductor configuration procedure and a verification procedure. The storage capacitor configuration procedure predetermines a test voltage and a rated bus voltage lower than the test voltage, determines a parameter of the storage capacitor according to the test voltage and uses the storage capacitor to supply the rated bus voltage. The storage inductor configuration procedure determines an inductance of a storage inductor to match the storage inductor and the primary coil of the transformer work in a discontinuous current mode. The verification procedure verifies whether the power factor of the converter exceeds 0.9.
    Type: Application
    Filed: April 16, 2009
    Publication date: October 21, 2010
    Applicant: FSP TECHNOLOGY INC.
    Inventors: Ming XU, Bo ZHANG, Kai YAO, Qiaoliang CHEN
  • Patent number: 7718713
    Abstract: A method of manufacturing super-absorbent polymer (SAP) which is powdery, insoluble in water, and able to absorb water, blood and urine with slight soluble substances. The method includes at least the following steps: mixing a monomer solution having at least 50 mol % of neutralized acrylic acid with polymerization initiators to synthesize a sticky precursor, wherein the monomer can be selected from acrylic acid, methacrylic acid, 2-acrylamido-2-methyl-propane sulfonic acid, or the mixtures thereof; mixing high hydrophilic epoxy compounds and polymerization initiators with the precursor and producing a gel via UV cross-linking; drying the gel at temperature of 100 to 250° C. to obtain a polymer; grinding and screening the polymer into constant particle size; coating the polymer with surface cross-linking agents; heating the polymer at temperature of 80 to 230° C.; and adding powdery inert inorganic salts into the polymer.
    Type: Grant
    Filed: October 2, 2006
    Date of Patent: May 18, 2010
    Assignee: Formosa Plastics Corporation
    Inventors: Kai Yao Shih, Cheng Chang Wu, Yung Chung Li
  • Publication number: 20100014326
    Abstract: A power factor correction (PFC) circuit includes an inductor, a diode, a storage capacitor, a switch and a control unit. The input power has a voltage fluctuation V1. The storage component absorbs a first voltage fluctuation and a switch regulation circuit absorbs a second voltage fluctuation V2. Thus output voltage from the PFC circuit is not a conventional constant voltage but a voltage of a great ripple. The PFC circuit further has a harmonic regulation unit. The harmonic regulation unit generates a voltage signal containing 3rd harmonic. The control unit receives a feedback signal and the voltage signal containing 3rd harmonic to generate a reference to the inductor current. Therefore, the inductor current contains 3rd harmonic. Thus power fluctuation absorbed and released by the capacitor is smaller. As a result energy storage capacitance can be reduced significantly.
    Type: Application
    Filed: July 1, 2009
    Publication date: January 21, 2010
    Inventors: Linlin GU, Ming Xu, Xinbo Ruan, Kai Yao
  • Patent number: 7646322
    Abstract: A folded R-2R ladder current-steering digital-to-analog converter is disclosed. In the folded R-2R ladder current-steering digital-to-analog converter, each node in the R-2R ladder is electrically coupled with a plurality of current sources with different weights. Therefore, the numbers of the resisters and current sources can be reduced, and efficient power saving and the high-speed operation can be achieved.
    Type: Grant
    Filed: September 4, 2008
    Date of Patent: January 12, 2010
    Assignee: Chung Yuan Christian University
    Inventors: Nan-Ku Lu, Chun-Chieh Chen, Kai-Yao Lin, Yi-Zhi Zeng
  • Publication number: 20090128387
    Abstract: A folded R-2R ladder current-steering digital-to-analog converter is disclosed. In the folded R-2R ladder current-steering digital-to-analog converter, each node in the R-2R ladder is electrically coupled with a plurality of current sources with different weights. Therefore, the numbers of the resisters and current sources can be reduced, and efficient power saving and the high-speed operation can be achieved.
    Type: Application
    Filed: September 4, 2008
    Publication date: May 21, 2009
    Applicant: CHUNG YUAN CHRISTIAN UNIVERSITY
    Inventors: NAN-KU LU, CHUN-CHIEH CHEN, KAI-YAO LIN, YI-ZHI ZENG
  • Publication number: 20080081848
    Abstract: A method of manufacturing super-absorbent polymer (SAP) which is powdery, insoluble in water, and able to absorb water, blood and urine with slight soluble substances. The method includes at least the following steps: mixing a monomer solution having at least 50 mol % of neutralized acrylic acid with polymerization initiators to synthesize a sticky precursor, wherein the monomer can be selected from acrylic acid, methacrylic acid, 2-acrylamido-2-methyl-propane sulfonic acid, or the mixtures thereof; mixing high hydrophilic epoxy compounds and polymerization initiators with the precursor and producing a gel via UV cross-linking; drying the gel at temperature of 100 to 250° C. to obtain a polymer; grinding and screening the polymer into constant particle size; coating the polymer with surface cross-linking agents; heating the polymer at temperature of 80 to 230° C.; and adding powdery inert inorganic salts into the polymer.
    Type: Application
    Filed: October 2, 2006
    Publication date: April 3, 2008
    Inventors: Kai Yao Shih, Cheng Chang Wu, Yung Chung Li
  • Publication number: 20050237583
    Abstract: The invention relates to a judgment apparatus for determining the size of a document. The judgment apparatus includes an automatic document feeding (ADF) with a scan window, a scanner carriage, and a decision module. The ADF transmits the document. The scanner carriage determines a first dimension of the scan window masked by the document, and outputs the first size. The decision module determines the size of the document according to the first dimension output by the scanner carriage.
    Type: Application
    Filed: April 6, 2005
    Publication date: October 27, 2005
    Inventors: Ya-Hui Chang, Kai-Yao Chen
  • Patent number: 6107622
    Abstract: In a light raster scanning system imaging a medium located on a movable stage and using bidirectional scanning, i.e. scanning during stage movement in two opposing directions, the problem of chevron artifacts (angle errors), due to the different stage movement directions, is overcome by a system of reflective optics including two optical elements dynamically movable relative to one another. One of the optical reflective elements is tilted or rotated relative to the other to compensate for the angle error causing the chevron artifacts. The amount of this tilt is dynamically altered depending on the direction of stage travel and also may be dynamically adjusted to maintain linearity of the scan pattern in spite of any other irregularities in stage velocity. Also an autofocus feature is provided, whereby the two reflective elements are moved relative to one another to dynamically alter the focus of the light beam onto the medium and hence overcome any defocus problems due to irregularities in the medium surface.
    Type: Grant
    Filed: June 5, 1998
    Date of Patent: August 22, 2000
    Assignee: Etec Systems, Inc.
    Inventors: Shi-Kay Yao, John M. Tamkin
  • Patent number: 6057921
    Abstract: Two axes laser interferometers are well known for determining the XY position of a stage, for instance for photolithography equipment. Each of the X and Y coordinates is measured to great precision by reflecting a laser beam from a long flat mirrored surface lying perpendicular to the axis of interest. Instead of using a single one-piece mirror having two reflective surfaces, three mirrors are provided in the configuration of two independent rigid bodies; there are two extended main mirrors each of which is formed on a separate optical element and a third smaller calibration mirror which is fabricated at a right angle at the end surface of one of the long mirrors or is adhesively bonded or held mechanically thereto. The angular relationship between the calibration mirror and the mirror to which it is attached is rigid and the orthogonality error is calibrated and recorded. This calibration mirror is a reference surface for the second elongated mirror to which it is nominally parallel.
    Type: Grant
    Filed: June 29, 1998
    Date of Patent: May 2, 2000
    Assignee: Etec Systems, Inc.
    Inventor: Shi-kay Yao
  • Patent number: 4671620
    Abstract: An acoustical phased array having improved interaction efficiency and efficiency-bandwidth product. The array includes a body of acousto-optical material having one face grooved to form a number of sets of plane parallel surfaces, each set having n different height levels, where n is at least two. An electro-acoustic transducer is affixed to each surface and high-frequency signals are applied to the respective sets of transducers, each signal being phase-displaced by the same amount with respect to the signal applied to an adjacent set. The incremental height difference is 1/n of the phase difference between signals applied to adjacent sets, expressed in wavelengths, and this results in elimination of one lobe of what would otherwise be a twin-lobe far-field acoustic radiation pattern, and an approximate doubling in interaction efficiency.
    Type: Grant
    Filed: May 17, 1985
    Date of Patent: June 9, 1987
    Assignee: TRW Inc.
    Inventor: Shi-Kay Yao
  • Patent number: 4477725
    Abstract: A system for remote measurement of structural forces includes a plurality of microbend transducers mounted along the length of the structure for microbending an optical fiber in response to structural forces, such as stress acting upon an oil or gas pipeline or the like. An optical time domain reflectometer (OTDR) has a light source for launching a pulsed optical signal for passage through the fiber and a photodetector for sensing as a function of time the intensity of backscattered light reflected back through the fiber, wherein this sensed time function is correlated directly with discrete longitudinal positions along the length of the fiber and the structure. When one or more of the microbend transducers is activated to induce a microbend in the fiber in response to localized forces acting upon the structure, a portion of the backscattered light is lost at the microbend. This attenuation in backscattered light intensity is sensed quantitatively and positionally identified by the photodetector.
    Type: Grant
    Filed: August 27, 1981
    Date of Patent: October 16, 1984
    Assignee: TRW Inc.
    Inventors: Charles K. Asawa, Joseph W. Austin, Michael K. Barnoski, Allan R. Jackson, Stewart D. Personick, Shi-Kay Yao
  • Patent number: 4463254
    Abstract: A system for remote measurement of structural forces includes a plurality of microbend transducers mounted along the length of the structure for microbending an optical fiber in response to structural forces, such as stress acting upon an oil or gas pipeline or the like. An optical time domain reflectometer (OTDR) has a light source for launching a pulsed optical signal for passage through the fiber and a photodetector for sensing as a function of time the intensity of backscattered light reflected back through the fiber, wherein this sensed time function is correlated directly with discrete longitudinal positions along the length of the fiber and the structure. When one or more of the microband transducers is activated to induce a microbend in the fiber in response to localized forces acting upon the structure, a portion of the backscattered light is lost at the microbend. This attenuation in backscattered light intensity is sensed quantitatively and positionally identified by the photodetector.
    Type: Grant
    Filed: August 27, 1981
    Date of Patent: July 31, 1984
    Assignee: TRW Inc.
    Inventors: Charles K. Asawa, Michael K. Barnoski, Shi-Kay Yao
  • Patent number: 4459477
    Abstract: A system for remote measurement of structural forces includes a plurality of microbend transducers mounted along the length of the structure for microbending an optical fiber in response to structural forces, such as stress acting upon an oil or gas pipeline or the like. An optical time domain reflectometer (OTDR) has a light source for launching a pulsed optical signal for passage through the fiber and a photodetector for sensing as a function of time the intensity of backscattered light reflected back through the fiber, wherein this sensed time function is correlated directly with discrete longitudinal positions along the length of the fiber and the structure. When one or more of the microbend transducers is activated to induce a microbend in the fiber in response to localized forces acting upon the structure, a portion of the backscattered light is lost at the microbend. This attenuation in backscattered light intensity is sensed quantitatively and positionally identified by the photodetector.
    Type: Grant
    Filed: August 27, 1981
    Date of Patent: July 10, 1984
    Assignee: TRW Inc.
    Inventors: Charles K. Asawa, Joseph W. Austin, Michael K. Barnoski, Stewart D. Personick, Shi-Kay Yao
  • Patent number: 4421979
    Abstract: A system for remote measurement of structural forces includes a plurality of microbend transducers mounted along the length of the structure for microbending an optical fiber in response to structural forces, such as stress acting upon an oil or gas pipeline or the like. An optical time domain reflectometer (OTDR) has a light source for launching a pulsed optical signal for passage through the fiber and a photodetector for sensing as a function of time the intensity of backscattered light reflected back through the fiber, wherein this sensed time function is correlated directly with discrete longitudinal positions along the length of the fiber and the structure. When one or more of the microbend transducers is activated to induce a microbend in the fiber in response to localized forces acting upon the structure, a portion of the backscattered light is lost at the microbend. This attenuation in backscattered light intensity is sensed quantitatively and positionally identified by the photodetector.
    Type: Grant
    Filed: August 27, 1981
    Date of Patent: December 20, 1983
    Assignee: TRW Inc.
    Inventors: Charles K. Asawa, Shi-Kay Yao
  • Patent number: 4355869
    Abstract: An optical system including a radio frequency signal input; a chirp signal input; a source for emitting a beam of radiation; an acousto-optical modulator disposed in the path of the beam and functioning to modulate the beam with the radio frequency signal and the chirp signal to produce a modulated beam; and a single detector disposed in the path of the third modulated beam. The inventor further provides electronic alignment and focusing by changing the chirp frequency.
    Type: Grant
    Filed: May 29, 1980
    Date of Patent: October 26, 1982
    Assignee: Rockwell International Corporation
    Inventor: Shi-Kay Yao
  • Patent number: 4354247
    Abstract: An optical system for performing a cosine transform on an input RF signal is described. The optical system includes a source for emitting a beam of radiation, and an acoustic-optical modulation device disposed in the path of the beam and functioning to modulate at least two spaced-apart spatial portions of the beam with different signals to produce two modulated beams.A Fourier transfer lens is provided which is disposed in the path of the two modulated beams for combining the two beams, and a detector is disposed in the path of the Fourier transform beam at the focal plane of the Fourier transfer lens.
    Type: Grant
    Filed: May 29, 1980
    Date of Patent: October 12, 1982
    Assignee: Rockwell International Corporation
    Inventor: Shi-Kay Yao
  • Patent number: H77
    Abstract: A low loss optical waveguide is provided by taking a silicon substrate with a silicon dioxide waveguide thereon and depositing lead on the air interface surface of the silicon dioxide. The lead is then oxidized and diffused into the silicon dioxide creating a high optical quality, high index region at the air interface of the waveguide. This allows transmitted waveguide light energy directed into the silicon dioxide to be transmitted in the lead oxide diffused portion of the waveguide, keeping the energy away from the lossy silicon substrate, and thereby providing a low loss planar waveguide.
    Type: Grant
    Filed: April 1, 1983
    Date of Patent: July 1, 1986
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Shi-Kay Yao, Joseph W. Niesen