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:
Sep. 24, 1991
Filed:
Apr. 27, 1990
Daniel J Chaplin, Nevada City, CA (US);
The Grass Valley Group, Inc., Nevada City, CA (US);
Abstract
A keyer with variable shaping combines the benefits of a luminance keyer with those of a linear keyer using a single set of gain and clip controls. A key signal is input to a first amplifier having a high gain that is variable over an upper portion of a gain control signal's range. The output of the first amplifier is compared with a clip control signal and input to a second amplifier having a low gain that is variable over a lower portion of the gain control signal's range. The second amplifier includes a feedback circuit that provides minimum gain and shaping when the feedback signal is maximum, and provides maximum gain and shaping when the feedback signal is minimum.