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. 16, 1990
Filed:
Jun. 28, 1989
Kiyoshi Kohiyama, Tokyo, JP;
Hidenaga Takahashi, Tokyo, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
In an apparatus for detecting a phase difference between two digital signals including an n stage delay circuit, an n bit register connected to the n stage delay circuit, a signal encoding means connected to the n bit register, and a compensation circuit connected to the encoder, a test signal is applied to the delay circuit first and two different delayed data are obtained by applying a reference signal to the n bit register twice, the delay characteristics of the delay circuit is calculated by using two different data and the period time of the two reference signals, then a signal to be subjected to phase difference detection is applied to the delay circuit to obtain delayed data by applying a reference signal to the n bit register, the delayed data is compensated at the compensating circuit by using the delay characteristics of the delay circuit. Thus, an accurate phase difference between two digital signals is obtained.