Patents by Inventor Ko-Han CHEN

Ko-Han CHEN 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).

  • Method and apparatus for driving light emitting diode
    Patent number: 9144124
    Abstract: An LED driving method is provided. The method includes the steps of: receiving a brightness control signal, wherein the brightness control signal represents a duty cycle of an LED within a pulse width modulation cycle, and the duty cycle is indicated by a plurality of illuminating clocks; dividing the PWM cycle into a plurality of sub-PWM cycles; and equally distributing the illuminating clocks to each of the sub-PWM cycles.
    Type: Grant
    Filed: May 21, 2013
    Date of Patent: September 22, 2015
    Assignee: Princeton Technology Corporation
    Inventors: Ming-Yuan Tsao, Ko-Han Chen
  • Power-on reset circuit
    Patent number: 8872555
    Abstract: A power-on reset circuit has a first impedance device, a first switch device, a first capacitor, a second switch device, a third switch device, a fourth switch device, a second impedance device, a second capacitor, and a control circuit coupled to a reset input terminal of a circuit device. When the power-on reset circuit is supplied with electric power, the first switch device and the third switch device are turned on and the second switch device and the fourth switch device are turned off. When the electric power is removed from the power-on reset circuit, the first switch device and the third switch device are turned off and the second switch device and the fourth switch device are turned on. The second capacitor is discharged through the fourth switch to a voltage level being close to a ground voltage.
    Type: Grant
    Filed: June 18, 2013
    Date of Patent: October 28, 2014
    Assignee: Princeton Technology Corporation
    Inventors: Ko-Han Chen, Ming-Yuan Tsao, Dang-Ching Lin, Shih-Chou Kuo
  • METHOD AND APPARATUS FOR DRIVING LIGHT EMITTING DIODE
    Publication number: 20140167636
    Abstract: An LED driving method is provided. The method includes the steps of: receiving a brightness control signal, wherein the brightness control signal represents a duty cycle of an LED within a pulse width modulation cycle, and the duty cycle is indicated by a plurality of illuminating clocks; dividing the PWM cycle into a plurality of sub-PWM cycles; and equally distributing the illuminating clocks to each of the sub-PWM cycles.
    Type: Application
    Filed: May 21, 2013
    Publication date: June 19, 2014
    Applicant: Princeton Technology Corporation
    Inventors: Ming-Yuan TSAO, Ko-Han CHEN
  • POWER-ON RESET CIRCUIT
    Publication number: 20140159784
    Abstract: A power-on reset circuit has a first impedance device, a first switch device, a first capacitor, a second switch device, a third switch device, a fourth switch device, a second impedance device, a second capacitor, and a control circuit coupled to a reset input terminal of a circuit device. When the power-on reset circuit is supplied with electric power, the first switch device and the third switch device are turned on and the second switch device and the fourth switch device are turned off. When the electric power is removed from the power-on reset circuit, the first switch device and the third switch device are turned off and the second switch device and the fourth switch device are turned on. The second capacitor is discharged through the fourth switch to a voltage level being close to a ground voltage.
    Type: Application
    Filed: June 18, 2013
    Publication date: June 12, 2014
    Inventors: Ko-Han CHEN, Ming-Yuan TSAO, Dang-Ching LIN, Shih-Chou KUO