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:
Jun. 12, 2001
Filed:
Jul. 13, 1999
Yukio Takemura, Kawasaki, JP;
Michitaka Setani, Kawasaki, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An original sensing device for sensing the presence/absence of an original placed on an original tray of a document feeder by using an output signal from a photodetector which receives a light beam emitted by a light projector and reflected by the original tray, including a projecting/photodetecting unit including the light projector and the photodetector, and an optical member interposed between the projecting/photodetecting unit and the original tray. The light projector and the photodetector are arranged to oppose said original tray such that a projecting optical axis and a photodetecting optical axis are substantially parallel to each other. Boundary surfaces of the optical member are constructed such that a portion of a light beam on the projecting optical axis emerges toward a direction of said original tray via at least two boundary surfaces, a reflected light beam from the original tray is guided to said photodetector via at least two boundary surfaces, and other part of the light beam on the projecting optical axis does not emerge toward the direction of said original tray but is reflected by a boundary surface facing the original tray and is totally reflected by a boundary surface facing the photodetector.