Patents by Inventor Clifford J. Ortmeyer, II

Clifford J. Ortmeyer, II 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 circuit for driving a low voltage light emitting diode
    Patent number: 8324825
    Abstract: In a method for producing a control signal for regulating a drive current for driving an LED, a current through the LED is sensed, wherein the LED is driven by a power converter output, and wherein an output voltage of the power converter is proportionately controlled by a control signal. Next, a power supply voltage is sensed. The control signal is produced for the power converter, wherein the control signal is proportional to a difference between a reference voltage and the current through the LED. The control signal is then offset in response to the power supply voltage to reduce the current through the LED as the power supply voltage drops.
    Type: Grant
    Filed: August 11, 2008
    Date of Patent: December 4, 2012
    Assignee: STMicroelectronics, Inc.
    Inventors: Jianwen Shao, Clifford J. Ortmeyer, II
  • Method and Circuit for Driving a Low Voltage Light Emitting Diode
    Publication number: 20080297069
    Abstract: In a method for producing a control signal for regulating a drive current for driving an LED, a current through the LED is sensed, wherein the LED is driven by a power converter output, and wherein an output voltage of the power converter is proportionately controlled by a control signal. Next, a power supply voltage is sensed. The control signal is produced for the power converter, wherein the control signal is proportional to a difference between a reference voltage and the current through the LED. The control signal is then offset in response to the power supply voltage to reduce the current through the LED as the power supply voltage drops.
    Type: Application
    Filed: August 11, 2008
    Publication date: December 4, 2008
    Applicant: STMICROELECTRONICS, INC.
    Inventors: Jianwen Shao, Clifford J. Ortmeyer, II
  • Method and circuit for driving a low voltage light emitting diode
    Patent number: 7425803
    Abstract: In a method for producing a control signal for regulating a drive current for driving an LED, a current through the LED is sensed, wherein the LED is driven by a power converter output, and wherein an output voltage of the power converter is proportionately controlled by a control signal. Next, a power supply voltage is sensed. The control signal is produced for the power converter, wherein the control signal is proportional to a difference between a reference voltage and the current through the LED. The control signal is then offset in response to the power supply voltage to reduce the current through the LED as the power supply voltage drops.
    Type: Grant
    Filed: August 31, 2004
    Date of Patent: September 16, 2008
    Assignee: STMicroelectronics, Inc.
    Inventors: Jianwen Shao, Clifford J. Ortmeyer, II
  • Ballast circuit
    Patent number: 6677719
    Abstract: A ballast circuit and method for operating a lamp includes a lamp preheat/ignition circuit for preheating and igniting the lamp. A ballast controller integrated circuit is operatively connected to the preheat/ignition circuit wherein the lamp preheat/ignition circuit is operatively controlled in a a) preheating mode wherein the lamp is preheated at a preheating frequency for a predetermined period of time; b) a user programmable intermediate ignition mode wherein the lamp is heated at an intermediate ignition frequency that is lower than the preheating frequency; and c) an operating mode wherein the lamp is operated at a final operating frequency that is lower than the intermediate ignition frequency.
    Type: Grant
    Filed: June 3, 2002
    Date of Patent: January 13, 2004
    Assignee: STMicroelectronics, Inc.
    Inventor: Clifford J. Ortmeyer, II