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. 16, 1989
Filed:
Apr. 05, 1988
Tohru Nakajima, Saitama, JP;
Hisao Nakamura, Saitama, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
A video signal output circuit which permits switching an output video signal from one input video signal source to another without loss of synchronization of the video monitor. A first pulse signal is produced synchronized with the vertical synchronizing signal of the first video signal. A first detector circuit detects the phase difference between the first pulse signal and a second pulse signal synchronized with the vertical synchronizing signal of the second video signal, and the period of generation of the first pulse signal is controlled in response to the phase detected phase difference. A second phase detector detects when the phase difference between the first pulse signal and the second pulse signal is within a predetermined range easily tolerated by the monitor. Switching from the first to the second video source is permitted when this phase difference is within the predetermined range.