Patents by Inventor Chi-Shing Chan

Chi-Shing Chan 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).

  • Prism for optical system
    Patent number: 5978144
    Abstract: A prismatic optical device employs an improved prismatic image erecting system with curved refracting surfaces. The optical device can be any one of a wide variety of known devices such as telescopes and binoculars which include an objective, an image erecting system and an ocular. The erecting prism of the optical system is preferably an integral prism formed of optical quality plastic and may comprise a Porro erecting prism system or an image erecting system employing pentangular or roof prisms.
    Type: Grant
    Filed: November 4, 1997
    Date of Patent: November 2, 1999
    Assignee: Hong Kong Productivity Council
    Inventors: Li-Man Li, Chi-Shing Chan, Chi-Keung Chung