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:
Sep. 15, 1998
Filed:
Sep. 19, 1996
Motonobu Kawabata, Kyoto, JP;
Dainippon Screen Mfg. Co. Ltd., Kyoto, JP;
Abstract
In an optical beam scanning apparatus in which an optical beam from a light source impinges upon a deflecting system and a deflected optical beam from said deflecting system scans a surface-to-be-scanned through a scanning lens in a main scanning direction, with a curvature of image surface correction method of the present invention, curvature of image surface is reduced without improving the surface accuracy of the scanning lens. A lens holder (14) is freely movable on an optical base (3) along a guide (15). When an adjustment screw (16) is manipulated, the lens holder (14) is moved so that a collimator lens (12) is moved along an optical axis (OA) and positioned. As the collimator lens (12) is moved, the degree of parallel of an optical beam which is emitted toward a galvanometer (30) is changed and the shape of an image surface is adjusted, so that the image surface is positioned within the depth of focus of the optical beam scanning apparatus over an entire scanning range. Hence, it is possible to perform drawing with an excellent image quality.