Patents by Inventor Kuo Wen Chang

Kuo Wen Chang 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).

  • Retrofocus-type lens system
    Patent number: 6631037
    Abstract: A retrofocus-type lens system comprises, in order of the object side, three lens units wherein the first lens unit serves as the front lens group of negative refractive power and the second lens unit in combination with the third lens unit serves as the rear lens group of positive refractive power. The first lens unit has meniscus lens elements with concave surfaces on the object side. A stop is placed between the front lens group including the meniscus lens elements and the rear lens group including both the second and the third lens units. The lens element on the image side of the first lens unit of the front lens group is of negative power, and the lens element on the image side of the third lens unit is a negative biconcave lens.
    Type: Grant
    Filed: February 6, 2002
    Date of Patent: October 7, 2003
    Assignee: NuCam Corporation
    Inventor: Kuo-Wen Chang
  • Retrofocus-type lens system
    Publication number: 20030090815
    Abstract: A retrofocus-type lens system comprises, in order of the object side, three lens units wherein the first lens unit serves as the front lens group of negative refractive power and the second lens unit in combination with the third lens unit serves as the rear lens group of positive refractive power. The first lens unit has meniscus lens elements with concave surfaces on the object side. A stop is placed between the front lens group including the meniscus lens elements and the rear lens group including both the second and the third lens units. The lens element on the image side of the first lens unit of the front lens group is of negative power, and the lens element on the image side of the third lens unit is a negative biconcave lens.
    Type: Application
    Filed: February 6, 2002
    Publication date: May 15, 2003
    Applicant: NuCam Corporation
    Inventor: Kuo-Wen Chang