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:
Jun. 17, 2003
Filed:
Jul. 27, 1999
Applicant:
Inventor:
Akira Yukawa, Tokyo, JP;
Assignee:
NEC Electronics Corporation, Kanagawa, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01R 2/500 ; G01R 2/700 ;
U.S. Cl.
CPC ...
G01R 2/500 ; G01R 2/700 ;
Abstract
An apparatus for measuring an impedance produces an alternating current from digital codes representative of a sine wave, and converts an ac voltage due to an alternating current flowing into an object to a digital signal; a multiplier successively multiplies the binary values of the digital signal by the binary values of the digital codes representing the sine wave and a cosine wave, an accumulator successively adds the products, and a microcomputer calculates the impedance of the object on the basis of the sums of products, thereby improving the accuracy of the calculating result.