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:
Mar. 24, 1992
Filed:
Jun. 29, 1990
William E Wolf, Chesapeake City, MD (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
A control arrangement for a galvanometer driven mirror whereby the angle of incidence of a beam on a holographic recording material is controlled includes a laser source and associated detector. The detector responds to a reflected position sensing beam incident thereon to generate electric currents. A ratio network forms the ratio of the sum and difference of the currents to generate an actual mirror position signal that is independent of the power output of the source of the sensing beam. An integrator is responsive to the error between the signal representative of the actual mirror position and a reference signal representative of a predetermined position of the mirror for forming a galvanometer position signal.