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:
Dec. 01, 1998
Filed:
Feb. 25, 1997
Hiroyuki Yoshimura, Kanagawa, JP;
Akira Morita, Tokyo, JP;
Fuji Electric Co., Ltd., Kawasaki, JP;
Abstract
A phase difference measuring apparatus for precisely measuring a phase difference between two input signals having the same frequency sent from, for example, a Coriolis type mass flowmeter. A differential amplifier in the apparatus provides the sum or difference of the two input signals and a multiplexor sequentially selects and outputs to an A/D converter the two input signals and the output of the differential amplifier. The A/D converter converts the output of the multiplexor into digital data and a digital signal processor or a microcomputer calculates the phase difference between the two input signals based on the converted digital data. The apparatus may further comprise a function that an error caused by the difference of the transfer characteristics of a filter and the A/D converter is compensated using a reference signal which is selected from the two input signals.