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:
Jul. 12, 1994
Filed:
Feb. 11, 1993
Hideo Imaizumi, Gunma, JP;
Yoshiaki Takahashi, Ohta, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
A frequency of a first VCO (12) for generating a carrier of a video IF signal is set by using a frequency of a second VCO (15) as reference. The oscillation frequency of the second VCO (15) is controlled in response to the phase difference between an output signal of the first VCO (12) and the video IF signal. As a result, the output signal phase of the first VCO (12) is adjusted, and the output signal is locked to a carrier frequency of the video IF signal. Thus, the oscillation frequency of the first VCO (12) can be set automatically. Further, a signal for the phase difference between the output signal of the first VCO (12) and the video IF signal is also applied to the first VCO (12), thereby improving the stability of circuit operation.