Patents by Inventor Muh-fa Chen

Muh-fa 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).

  • Wide angle lens attachment
    Patent number: 4367928
    Abstract: A wide angle attachment adapted to be used with a prime lens. The lens comprises four elements in three groups. The combination of the attachment with a prime lens results in a lens system having a larger field of view than the field of view of the prime lens by itself.
    Type: Grant
    Filed: April 11, 1980
    Date of Patent: January 11, 1983
    Assignee: Vivitar Corporation
    Inventors: Melvyn H. Kreitzer, Muh-fa Chen