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:
Aug. 13, 1985
Filed:
Jun. 17, 1983
Applicant:
Inventor:
John W Reeds, Thousand Oaks, CA (US);
Assignee:
Hughes Aircraft Company, El Segundo, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ; H01L / ;
U.S. Cl.
CPC ...
2504911 ; 250397 ;
Abstract
Benchmark detector (46) has two light pipe fingers (48, 50) which lie adjacent to each other at an acute angle to the orthogonal axes of movement of the stage on which the benchmark is positioned. The light pipe fingers have notches which define a rectangular opening therebetween through which a benchmark (52) can be excited to produce secondary electrons. Scintillator material adjacent the notches produces photons in the light pipes so that the position of the benchmark with respect to the detector can be established.