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:
Oct. 30, 1990
Filed:
Dec. 05, 1988
David M Orlicki, Rochester, NY (US);
William T Fearnside, Fishers, NY (US);
Eastman Kodak Company, Rochester, NY (US);
Abstract
In an optical recording system, automatic gain control circuitry is provided to maintain the gain of the focus (or tracking) servo system substantially constant and independent of intensity variations in the light beam used to detect focus (or tracking) error. According to a preferred embodiment, such circuitry comprises two cascaded stages, i.e., a switchable gain first stage for effecting coarse gain changes on command (e.g. when switching between write and read modes), and a non-linear feedback second stage for adjusting the coarsely trimmed output of the first stage to achieve overall constant focus (or tracking) error gain.