Patents by Inventor Wei-Kang Cheng

Wei-Kang Cheng 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: 9048848
    Abstract: A phase-locked loop circuit using a multi-curve voltage-controlled oscillator (VCO) having a set of operating curves, each operating curve corresponding to a different frequency range over a control voltage range. The phase-locked loop circuit includes a phase and frequency detector driving a charge pump and a digital control circuit configured to perform a closed loop curve search operation to select one of the operating curves in the multi-curve VCO and to perform a curve tracking operation using the selected operating curve, the selected operating curve being used by the VCO to generate an output signal with an output frequency being equal or close to a target frequency of the phase-locked loop. In one embodiment, the digital control circuit increases the charge pump current above a nominal current value during the closed loop curve search operation and set the charge pump current to the nominal current during the curve tracking operation.
    Type: Grant
    Filed: September 23, 2014
    Date of Patent: June 2, 2015
    Assignee: Micrel, Inc.
    Inventors: Juinn-Yan Chen, Wei-Kang Cheng
  • Patent number: 9030241
    Abstract: A phase-locked loop circuit using a multi-curve voltage-controlled oscillator (VCO) having a set of operating curves, each operating curve corresponding to a different frequency range over a control voltage range. The phase-locked loop circuit includes a digital control circuit configured to generate a curve select signal using a closed loop curve search operation to select one of the operating curves in the multi-curve VCO, the selected operating curve being used by the VCO to generate an output signal with an output frequency being equal or close to a target frequency of the phase-locked loop. In one embodiment, the digital control circuit implements a binary jump method and an operating curve is selected when the operating curve has an output frequency meeting the target frequency with the control voltage being within a first voltage range being a narrowed and centered voltage range within the control voltage range.
    Type: Grant
    Filed: April 30, 2013
    Date of Patent: May 12, 2015
    Assignee: Micrel, Inc.
    Inventors: Juinn-Yan Chen, Wei-Kang Cheng
  • Patent number: 9029898
    Abstract: The present invention relates to a light emitting diode (LED). The LED comprises an LED die, one or more metal pads, and a fluorescent layer. The characteristics of the present invention include that the metals pads are left exposed for the convenience of subsequent wiring and packaging processes. In addition, the LED provided by the present invention is a single light-mixing chip, which can be packaged directly without the need of coating fluorescent powders on the packaging glue. Because the fluorescent layer and the packaging glue are not processed simultaneously and are of different materials, the stress problem in the packaged LED can be reduced effectively.
    Type: Grant
    Filed: February 6, 2014
    Date of Patent: May 12, 2015
    Assignee: Formosa Epitaxy Incorporation
    Inventors: Chi-Chih Pu, Chen-Hong Lee, Tzu-Hsiang Wang, Sheng-Hung Hsu, Wei-Kang Cheng, Shyi-Ming Pan
  • Publication number: 20150116980
    Abstract: The invention is an illumination system comprising a semiconductor light source module. The illumination system comprises a reflector comprising a curved reflective surface, a holder coupled to the reflector, and a semiconductor light source module comprising a first light-emitting unit and a second light-emitting unit. The holder comprises a second holding section and a first holding section disposed between the reflector and the second holding section. The semiconductor light-source module is disposed on the second holding section to face the curved reflective surface. An angle between at least a light-emitting unit and at least a part of the first holding section is formed and ranges from 145 to 175 degrees.
    Type: Application
    Filed: May 2, 2014
    Publication date: April 30, 2015
    Applicants: DJ AUTO COMPONENTS CORP., FORMOSA EPITAXY INCORPORATION
    Inventors: JEN-CHIH LI, LUNG-KUAN LAI, CHUN-WEI CHEN, SHYI-MING PAN, WEI-KANG CHENG, CHUN-CHENG LIN, JUN-FU YANG, CHIH-CHIEH WANG
  • Publication number: 20150097202
    Abstract: A light-emitting diode (LED) is provided. An LED die includes a first semiconductor layer, a light-emitting layer, a second semiconductor layer, a first electrode and a second electrode. At least a part of the first semiconductor is exposed from the light emitting layer and the second semiconductor layer. The first electrode and the second electrode is disposed on top of the exposed first semiconductor layer and the second semiconductor layer respectively. At least two metal pads are disposed on top of the first electrode and the second electrode of the LED die respectively. Each of the metal pads has a side surface. A fluorescent layer is disposed on a surface of the LED die. The fluorescent layer directly contacts with the side surfaces of the metal pads and fills a gap between the metal pads.
    Type: Application
    Filed: December 1, 2014
    Publication date: April 9, 2015
    Inventors: Wei-Kang Cheng, Jia-Lin Li, Shyi-Ming Pan, Kuo-Chin Huang
  • Publication number: 20150077164
    Abstract: A phase-locked loop circuit using a multi-curve voltage-controlled oscillator (VCO) having a set of operating curves, each operating curve corresponding to a different frequency range over a control voltage range. The phase-locked loop circuit includes a phase and frequency detector driving a charge pump and a digital control circuit configured to perform a closed loop curve search operation to select one of the operating curves in the multi-curve VCO and to perform a curve tracking operation using the selected operating curve, the selected operating curve being used by the VCO to generate an output signal with an output frequency being equal or close to a target frequency of the phase-locked loop. In one embodiment, the digital control circuit increases the charge pump current above a nominal current value during the closed loop curve search operation and set the charge pump current to the nominal current during the curve tracking operation.
    Type: Application
    Filed: September 23, 2014
    Publication date: March 19, 2015
    Inventors: Juinn-Yan Chen, Wei-Kang Cheng
  • Publication number: 20150069573
    Abstract: A capacitor structure is provided, which includes a conductive substrate, a first dielectric layer, and a first metal layer. The conductive substrate includes a first surface and at least one first concave located on the first surface. The first dielectric layer covers the first surface and the first concave. The first metal layer covers the first dielectric layer, wherein the first dielectric layer and the first metal layer respectively have concave structures corresponding to the first concave. A stack-type capacitor structure is also provided.
    Type: Application
    Filed: January 16, 2014
    Publication date: March 12, 2015
    Applicant: Formosa Epitaxy Incorporation
    Inventors: Chih-Shu Huang, Shyi-Ming Pan, Wei-Kang Cheng
  • Publication number: 20150061526
    Abstract: A light emitting device including a light emitting component is provided, wherein said light emitting comprising an integrated light emitting diode and a semiconductor field effect transistor. The semiconductor field effect transistor may prevent situations such as overheating and voltage instability by controlling a current passing through the light emitting diode as well as enhancing the ability to withstand electrostatic discharge and reducing cost of the light emitting device in multiple aspects.
    Type: Application
    Filed: October 24, 2014
    Publication date: March 5, 2015
    Inventors: Chih-Shu Huang, Chun-Ju Tun, Shyi-Ming Pan, Wei-Kang Cheng, Keng-Ying Liao
  • Patent number: 8933469
    Abstract: The present invention relates to a high-voltage light-emitting device suitable for light-emitting diode chip array module. The device comprises a set of light emitting diode chips, about 18˜25 chips, deposited on a substrate by using a non-matrix arrangement. Through the adjustments, the high-voltage light-emitting device of the present invention has optimized luminous efficiency.
    Type: Grant
    Filed: October 19, 2012
    Date of Patent: January 13, 2015
    Assignee: Formosa Epitaxy Incorporation
    Inventors: Hui-Ching Feng, Chen-Hong Lee, Wei-Kang Cheng, Shyi-Ming Pan
  • Patent number: 8927303
    Abstract: The present invention relates to a light-emitting diode (LED) and a method for manufacturing the same. The LED comprises an LED die, one or more metal pads, and a fluorescent layer. The characteristics of the present invention include that the metals pads are left exposed for the convenience of subsequent wiring and packaging processes. In addition, the LED provided by the present invention is a single light-mixing chip, which can be packaged directly without the need of coating fluorescent powders on the packaging glue. Because the fluorescent layer and the packaging glue are not processed simultaneously and are of different materials, the stress problem in the packaged LED can be reduced effectively.
    Type: Grant
    Filed: September 2, 2009
    Date of Patent: January 6, 2015
    Assignee: Formosa Epitaxy Incorporation
    Inventors: Wei-Kang Cheng, Jia-Lin Li, Shyi-Ming Pan, Kuo-Chi Huang
  • Patent number: 8872556
    Abstract: A phase-locked loop circuit using a multi-curve voltage-controlled oscillator (VCO) having a set of operating curves, each operating curve corresponding to a different frequency range over a control voltage range. The phase-locked loop circuit includes a phase and frequency detector driving a charge pump and a digital control circuit configured to generate a curve select signal using a closed loop curve search operation to select one of the operating curves in the multi-curve VCO, the selected operating curve being used by the VCO to generate an output signal with an output frequency being equal or close to a target frequency of the phase-locked loop. In one embodiment, the digital control circuit increases the charge pump current above a nominal current value during the closed loop curve search operation and set the charge pump current to the nominal current value after an operating curve is selected.
    Type: Grant
    Filed: April 30, 2013
    Date of Patent: October 28, 2014
    Assignee: Micrel, Inc.
    Inventors: Juinn-Yan Chen, Wei-Kang Cheng
  • Patent number: D724552
    Type: Grant
    Filed: January 21, 2014
    Date of Patent: March 17, 2015
    Assignee: Formosa Epitaxy Incorporation
    Inventors: Lung-Kuan Lai, Jen-Chih Li, Wei-Kang Cheng, Shyi-Ming Pan
  • Patent number: D731087
    Type: Grant
    Filed: July 29, 2013
    Date of Patent: June 2, 2015
    Assignee: Formosa Epitaxy Incorporation
    Inventors: Chi-Chih Pu, Chen-Hong Lee, Li-Kai Lu, Wei-Kang Cheng, Shyi-Ming Pan
  • Patent number: D731088
    Type: Grant
    Filed: July 29, 2013
    Date of Patent: June 2, 2015
    Assignee: Formosa Epitaxy Incorporation
    Inventors: Wei-Kang Cheng, Chen-Hong Lee, Chi-Chih Pu, Shih-Chieh Tang, Shyi-Ming Pan
  • Patent number: D731089
    Type: Grant
    Filed: July 30, 2013
    Date of Patent: June 2, 2015
    Assignee: Formosa Epitaxy Incorporation
    Inventors: Wei-Kang Cheng, Chen-Hong Lee, Chi-Chih Pu, Shih-Chieh Tang, Shyi-Ming Pan
  • Patent number: D731090
    Type: Grant
    Filed: July 30, 2013
    Date of Patent: June 2, 2015
    Assignee: Formosa Epitaxy Incorporation
    Inventors: Chen-Hong Lee, Chi-Chih Pu, Lung-Kuan Lai, Wei-Kang Cheng, Shyi-Ming Pan
  • Patent number: D731091
    Type: Grant
    Filed: July 30, 2013
    Date of Patent: June 2, 2015
    Assignee: Formosa Epitaxy Incorporation
    Inventors: Wei-Kang Cheng, Chen-Hong Lee, Chi-Chih Pu, Shih-Chieh Tang, Shyi-Ming Pan
  • Patent number: D731680
    Type: Grant
    Filed: July 30, 2013
    Date of Patent: June 9, 2015
    Assignee: Formosa Epitaxy Incorporation
    Inventors: Chi-Chih Pu, Chen-Hong Lee, Li-Kai Lu, Wei-Kang Cheng, Shyi-Ming Pan
  • Patent number: D731681
    Type: Grant
    Filed: July 30, 2013
    Date of Patent: June 9, 2015
    Assignee: Formosa Epitaxy Incorporation
    Inventors: Chi-Chih Pu, Chen-Hong Lee, Tzu-Hsiang Wang, Wei-Kang Cheng, Shyi-Ming Pan
  • Patent number: D732487
    Type: Grant
    Filed: January 21, 2014
    Date of Patent: June 23, 2015
    Assignee: Formosa Epitaxy Incorporation
    Inventors: Lung-Kuan Lai, Jen-Chih Li, Wei-Kang Cheng, Shyi-Ming Pan