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:
Dec. 25, 1984
Filed:
Oct. 08, 1982
Donald L Hornback, St. Joseph, MI (US);
Heath Company, St. Joseph, MI (US);
Abstract
A system for stabilizing the synchronization (sync) signal provided to a second video display generating a second video signal for the precise overlay thereon of a first video signal from a first video display having a relatively unstable sync signal is disclosed. The stable sync signal is generated by providing the multiplied unstable sync signal to a phase lock loop synthesizer in generating a higher multiple frequency signal which is synchronous with and phase locked with a sync signal of the first video signal and has a frequency which is an integral multiple of the horizontal active line period. The frequency of this signal is an integral multiple of the number of pixels, or dots, per active horizontal scan line of the second video display. By synchronizing the horizontal scan signal of a second video display with this high frequency signal, an integral number of pixels per horizontal scan line is provided. The synthesized, stable horizontal sync signal is then combined with a stable vertical sync signal to form a stable composite sync signal which is provided to the second video display permitting the synchronized overlay thereon of video signals from both video displays.