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:
Jun. 24, 1986
Filed:
Jan. 22, 1985
Chojuro Yamamitsu, Kawanishi, JP;
Ichiro Arimura, Kyoto, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A video signal recording and reproducing apparatus in which the luminance signal of a color video signal is frequency-modulated for recording and a reproduction frequency-modulated signal is frequency-demodulated to produce a reproduction video signal. A high frequency component is separated from the reproduction video signal and applied to a slice circuit comprising nonlinear elements including, for example, diodes connected in parallel with reverse polarities, thus eliminating noise at the low frequency signals included in the high frequency component. The apparatus further comprises a device for subtracting the sliced signal and the reproduced video signal one from the other in such a manner that the two signals are in phase with each other substantially at the desired ratio and in a predetermined frequency band. In this way, noise contained in the edge portion of the reproduction video signal, crosstalk and moire patterns caused at the time of azimuth recording without a guardband are decreased, thus improving the signal-to-noise ratio of the edge portion. If this apparatus is combined with a conventional device for reducing noise at the low frequency portion of the video signal, FM interleaving techniques and nonlinear emphasis, a high-density recording with narrow tracks and short wavelength is made possible, thereby producing a stable reproduced image with high S/N ratio having no undesired components.