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. 09, 1982
Filed:
Jun. 17, 1980
Tetsuo Shimizu, Tokyo, JP;
Universal Pioneer Corporation, Tokyo, JP;
Abstract
A video switch circuit for turning off and on picture portions of a composite video signal while leaving a synchronizing signal contained within the composite video signal so that a video device using the output video signal does not have to resynchronize when it is desired to switch on the overall composite video signal. A synthetic synchronizing signal is produced by operating an electronic switch between two fixed voltage levels corresponding to the pedestal level and synchronization peak level of the composite video signal in response to synchronization pulses separated therefrom. A second switch selects between the synthetic synchronizing signal and fixed voltage levels. A third output switch selects between the output of a clamp circuit which clamps one of the pedestal levels of a composite video signal and the synchronization peak level of the synchronizing signal contained within the composite video signal to a predetermined clamp potential and the output of the second switch. The second and third switches operate in response to externally supplied binary control signals.