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. 14, 1991
Filed:
Sep. 28, 1988
Yasuaki Morimoto, Villingen-Schwenningen, DE;
Heinz J Schroder, VS-Marbach, DE;
Friedhelm Zucker, Villingen-Schwenningen, DE;
Deutsche Thomson-Brandt GmbH, Villingen-Schwenningen, DE;
Abstract
An optical scanning arrangement in which a laser beam is generated by a source with a monitor diode. The laser beam is focused on an optical recording medium. A summing amplifier has a first input connected to a source of a periodic signal. This source of periodic signal is also connected to a first input of a multiplier. The multiplier has an output connected to a second input of the summing amplifier. This summing amplifier has an output connected to a positioning device in the focusing circuit for the laser beam. This focusing circuit has an actual value which is supplied to a third input of the summing amplifier. The multiplier receives a laser controlling signal on a second input for the purpose of maintaining the light output of the laser beam at a constant level.