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:
May. 31, 1983
Filed:
Jul. 31, 1980
William E Westell, Weston, MA (US);
Baird Corporation, Bedford, MA (US);
Abstract
An electro-optical device for generating data signals representing relative displacement between a master reticle with an optical aperture pattern in an object plane and a workpiece with an image of the aperture pattern in an image plane comprises a reference detector for sensing reference radiation directed towards the aperture pattern and a convolution detector for sensing the reference radiation reflected by the image pattern. A processor compares the phase of a signal generated by the convolution detector to the phase of a signal generated by the reference detector and generates the data signals defining the relative displacement between the master and the workpiece.