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:
Oct. 04, 1988
Filed:
May. 13, 1987
Takashi Okano, Saitama, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
A phase comparison circuit for producing a voltage error signal proportional to the difference in phase between a reference signal and an input signal. The reference signal is in the form of a sawtooth wave signal having a fixed frequency and fixed period. The input signal may vary widely in frequency. Sample pulses are derived from the input signal and are used to sample the ramps of the sawtooth signal to produce the error signal. When the frequency of the input signal differs from that of the reference signal to such an extent that the sample pulses do not occur during the ramps of the sawtooth signal, the sawtooth signal is repeatedly shifted in phase by one of two fixed amounts, depending upon the direction of the frequency difference, until the sample pulses occur during the ramps of the sawtooth signal.