Patents by Inventor Crystal Cheng

Crystal 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).

  • System and method for driving keypad backlight with balance-dimming capability
    Publication number: 20070085786
    Abstract: The present invention is an apparatus with balance-dimming capability for controlling the brightness of keypad backlight. The keypad backlight includes a plurality of light emitting diodes (LEDs). The apparatus includes a switch and a pulse-width modulation (PWM) generator. The switch is coupled between a power supply and the plurality of LEDs. The PWM generator is coupled to the power supply and the switch, and is capable of generating a PWM signal and controlling the brightness of the plurality of LEDs.
    Type: Application
    Filed: June 15, 2006
    Publication date: April 19, 2007
    Inventors: Jacky Lin, Crystal Cheng, Mingkwang Han