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. 11, 1987
Filed:
Jan. 21, 1986
David J Schoon, St. Paul, MN (US);
Printware, Inc., Mendota Heights, MN (US);
Abstract
Integrations of the historical numbers of times that a light beam scanned in an oscillatory course by a self-resonant galvanometer scanner does traverse so far in a first direction so as to impinge upon a Beginning-of-Trace (BOT) sensor, and does traverse so far in the opposite direction so as to impinge upon an End-of-Trace (EOT) sensor, are each used to separately control the voltage level developed in a first, BOT, electrical tank circuit and in a second, EOT, electrical tank circuit. Voltage from each tank circuit is amplified and applied to drive the self-resonant scanner, at a polarity to induce continued oscillation, during one-half of each oscillatory cycle. Amplitude and centering control thereby obtained of the sinusoidal oscillation of the self-resonant scanner is repeatable to better than one part in ten thousand between cycles.