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. 22, 1977
Filed:
Apr. 17, 1975
Matsushita Electric Industrial Co., Ltd., Osaka, JA;
Abstract
A ghost signal erasing system for television receivers in which a variable delay element utilizing the propagation of an elastic surface wave is used. The variable delay element includes a piezoelectric substrate, a plurality of first interdigitated electrode pairs formed on the substrate and a plurality of second interdigitated electrode pairs also formed on the substrate. An elastic surface wave produced by applying a video i-f signal to the first interdigitated electrode pairs is propagated along the surface of the piezoelectric substrate and taken up at the second interdigitated electrode pairs as a delayed a-c signal. By switching the first and second interdigitated electrode pairs to change the combination thereof, various delay times are obtained.