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, 1999
Filed:
Nov. 06, 1997
Mitutoyo Corporation, Kawasaki, JP;
Abstract
A focus detection unit including an optical system employing an image sandwiching method is disclosed. In the focus detection unit, a double slit mask (12) forming double sight lines is disposed on the optical axis of a lamp 10 while a single slit mask (16) forming an single sight line is disposed on the optical axis of a lamp (14). A triangular pole prism 18 is provided, consisting of first and second side surfaces, which together constitutes an edge, and a plane opposing the edge. The prism (18) is disposed such that the double and single sight line are able to irradiate the first and second side surfaces. The prism reflects the incoming lines toward a plane before the right-angle edge. Before the edge of the prism (18), a projection lens (20) is provided for forming images of the double and single sight lines which have been reflected by the prism (18) and separated by a mask (22), at a both aiming line imaging position 100. The images are projected onto a workpiece.