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:
Oct. 05, 1976
Filed:
Jul. 30, 1973
Canon Kabushiki Kaisha, Tokyo, JA;
Abstract
In the system disclosed, illuminating means form an optical path. An imaging system in the optical path includes a support for a mask, an imaging lens that focuses the image of the mask onto an optical plane, and a support that holds a component having a radiation-sensitive surface at the plane. A filter in the illuminating system blocks out light capable of affecting the radiation-sensitive material but allows passage of some visible light so that the image of the mask can be seen on the component. A half-mirror or beam splitter allows light from the imaging lens to focus on the component but deflects a portion of the light coming from the component toward an analyzer that detects the alignment between the image of the mask and the component. A second half-mirror or beam splitter near the first half-mirror compensates for radial shift of the image relative to the axis of the light path caused by the first half-mirror. The analyzer as well as the half-mirrors and the filter may be removed simultaneously after alignment to allow projection masking.