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. 18, 1991
Filed:
Jul. 06, 1990
Takao Okada, Hachioji, JP;
Akira Yagi, Sagamihara, JP;
Seizo Morita, Morioka, JP;
Nobuo Mikoshiba, Sendai, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
A scanning tunnel spectroscope comprises a generator for applying a bias voltage (V.sub.T) of a sin wave between a sample and probe, an I-V converter for converting a tunnel current flowing when the probe is set close to the sample, to a tunnel current representing voltage singal (I.sub.T), a detector for detecting the absolute value of the voltage signal (I.sub.t), and a servo circuit for servo-controlling a distance between the sample and probe using the absolute value with the servo time constant set larger than five times the period of the bias voltage. The information concerning the unevenness of the sample is obtained based on an output of the servo control means. A unit is provided for effecting the analog operation to derive a differential conductance based on the tunnel current on the real time basis and measuring the unevenness data and differential conductance between the sample and probe kept constant.