The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 07, 1996
Filed:
May. 11, 1995
Kazuo Fujibayashi, Kawasaki, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
In an apparatus for projecting an image by a projection lens onto a projection surface such as a screen surface or a surface of a recording medium, a prism for rotating the projection image is disposed on the exit side of the projection lens so that the entrance-side optical axis of the prism deviates from the exit-side optical axis thereof. An image-forming lens and a focal point detecting unit for detecting a focus state of the projection lens on the projection surface are disposed on a reflection side of a half mirror. When the focal point detecting unit detects the focus state of the projection lens, an adjusting unit effects a relative rotation between the prism and the image-forming lens and focal point detecting unit so as to make the exit-side optical axis of the prism coincide with the optical axis of the image-forming lens.