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:
Apr. 03, 1990
Filed:
Mar. 03, 1988
Toshio Idei, Nagaokakyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A video signal synthesizer operable to provide a multiplex video signal for producing a picture-in-picture effect on a display screen of a display device, for example, a cathode ray tube. The video signal synthesizer utilizes a PLL (phase-locked loop) circuit to generate a carrier signal synchronized with a color burst signal contained in the composite video signal for the reproduction of the main picture. The carrier signal is first delayed by a delay circuit and then utilized to remodulate the sub-picture signal which has been compressed with respect to time. This remodulated sub-picture signal is then subjected to time-division multiplexing through analog switch assembly. The delay time of the delay circuit is set so that both color subcarrier signals of the main picture and sub-picture signals may be matched in phase. Hence, the time-division multiplexing of the main picture signal and the sub-picture signal is possible without altering the characteristics of the color composite video signal. Thus, the necessity of the main picture signal being demodulated and modulated can be obviated.