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. 21, 1994
Filed:
Mar. 22, 1993
Shoichi Ohkawa, Tokyo, JP;
Kazuo Hushimi, Tokyo, JP;
JEOL Ltd., Tokyo, JP;
Abstract
A charge integration-type preamplifier for use with a radiation detector. The preamplifier is capable of electronically resetting a feedback capacitor, prevents intrusion of noise, and offers high resolution and high counting rate. An inverting amplifier is connected with the radiation detector and has an N-channel FET at its first stage. The output signal from this amplifier is fed back to the gate of the FET via an electrostatic capacitor. The preamplifier further includes a reset means which urges the voltage at the output of the inverting amplifier to rise via the capacitor by utilizing the feedback action. The junction between the gate and the source of the FET is forward-biased to release the charge stored in the capacitor to the source, thus resetting the capacitor. This maintains continuous operation. Thus, any interference causing noise between the radiation detector and the gate of the FET is not created. Furthermore, the disturbance caused by the resetting can be removed in a short time.