Patents by Inventor Ping-Yim Cheung

Ping-Yim Cheung 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).

  • Zoom lens assembly with focus adjustment mechanism
    Patent number: 6529338
    Abstract: A zoom lens assembly that couples a second lens group to a first lens group such that one cam mechanism is able to transfer both lens groups. The second lens group is further provided with a second cam mechanism that is able to provide the fine distance adjustment of the second lens group required for proper focus correction.
    Type: Grant
    Filed: January 31, 2001
    Date of Patent: March 4, 2003
    Inventor: Ping-Yim Cheung
  • System for supplying backup electricity
    Publication number: 20020140846
    Abstract: A system for supplying backup electricity from a secondary battery in which the power for the electric device is supplied by a primary battery while the secondary battery remains disconnected from the electric device until triggered by an action of the user.
    Type: Application
    Filed: March 29, 2001
    Publication date: October 3, 2002
    Inventor: Ping-Yim Cheung
  • Zoom lens assembly with focus adjustment mechanism
    Publication number: 20020114083
    Abstract: A zoom lens assembly that couples a second lens group to a first lens group such that one cam mechanism is able to transfer both lens groups. The second lens group is further provided with a second cam mechanism that is able to provide the fine distance adjustment of the second lens group required for proper focus correction.
    Type: Application
    Filed: January 31, 2001
    Publication date: August 22, 2002
    Inventor: Ping-Yim Cheung