Patents by Inventor A. Carmichael

A. Carmichael 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).

  • Image projection apparatus with a autofocusing system
    Patent number: 5434632
    Abstract: An image projection device comprising at least one display panel (26, 27, 28), a projection lens system (C) and a focus-error detection system is described. The focus-error detection system comprises an auxiliary radiation source (50) delivering a focus measuring beam (b), an auxiliary lens (61) for capturing radiation (b.sub.r) diffusely reflected by a projection screen (D), and a detection unit (60) for measuring the size of a spot (S) formed on the screen by the beam (b).
    Type: Grant
    Filed: March 2, 1994
    Date of Patent: July 18, 1995
    Assignee: U.S. Philips Corporation
    Inventor: A. Carmichael