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:
Jan. 14, 1992
Filed:
Dec. 08, 1989
Kazuo Kikuchi, Hitachi, JP;
Yoshifumi Homma, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An optical scanning apparatus includes a light source, an image forming optical unit, a deflection unit and an optical beam detection unit provided inside a deflection area of the optical beam, the optical beam detection unit receiving the optical beam and generating a synchronizing signal. The optical beam detecting unit includes a unidirectional converging optical unit. This unidirectional converging optical unit is provided on an optical path of the optical beam irradiating the scanned surface for further converging the optical beam in a direction perpendicular to the direction of scanning in addition to the convergence performed by the image forming optical unit, so that the optical beam irradiating a light receiving surface of the optical beam detection unit can be focused in advance of the light-receiving surface of the optical beam detection unit in the above direction. In consequence, the allowable range of a shift of the scanning path of the optical beam caused by the manufacturing errors of the deflection unit and of a shift of an optical axis caused by the fine adjustment errors or strains of the supporting members can be increased. It is thus possible to provide an optical beam scanning apparatus which has a simple configuration and which enables the accuracy with which the position of the optical beam is detected to be improved.