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:
Aug. 27, 1996
Filed:
Jul. 06, 1995
Shinichi Wakana, Kawasaki, JP;
Kazuyuki Ozaki, Kawasaki, JP;
Yoshiro Goto, Kawasaki, JP;
Yasutoshi Umehara, Tokyo, JP;
Fujitsu Limited, Kanagawa, JP;
Advantest Corporation, Tokyo, JP;
Abstract
In a signal measuring apparatus a distance between a sample and a probe is adjusted, a voltage is applied through the sample and the probe and a signal is measured using a current flowing through the sample and the probe. That is, a current flowing through the sample and the probe is chopped by a laser beam at a prescribed frequency and is fetched into a sampling apparatus to generate a sample value of the current. The sample value is compared with a current setting value arbitrarily set in a comparator, and a reference voltage is generated according to a compared result in a control logic circuit and a D/A converter. The reference voltage is fed back to the sampling apparatus to converge the current flowing through the sample and the probe at the current setting value. Therefore, a signal of the sample is measured according to the reference voltage on condition that the current is converged at the current setting value.