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:
Dec. 07, 1976
Filed:
Aug. 28, 1975
Donald Paul Jablonowski, Hopewell Township, Mercer County, NJ (US);
Western Electric Company, Inc., New York, NY (US);
Abstract
An improved method and apparatus are disclosed for monitoring relative movement between an incident beam of substantially coherent light and a grating on which the beam is directed, wherein light from the beam passing through the grating is sensed by a photodetector, and the cycles in the photodetector output signal are counted. The improvement comprises patterning the beam, transforming the patterned beam into a Fraunhofer diffraction pattern, and further diffracting the Fraunhofer diffraction pattern with the grating to cause an interference image, which is detected by the photodetector. Each two cycles in the output signal of the photodetector then correspond to a relative movement of the beam past one grating period.