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:
Sep. 26, 1995
Filed:
May. 20, 1994
John C Gibbons, Macedonia, OH (US);
Summit World Trade Corporation, Hudson, OH (US);
Abstract
An electronic gain control is disclosed for the photomultipliers of a gamma camera which assures that all photomultipliers in the camera have uniform gain for any given gamma event. A specific dynode in the photomultiplier is isolated from the line resistive voltage divider string in the photomultiplier which places each dynode under incremental voltages. A voltage is then applied to the isolated dynode which can vary anywhere from the voltage the isolated dynode would have had if inserted in the voltage divider string to the voltage that the immediately preceding or immediately succeeding dynode in the string has whereby the photomultiplier's gain is controlled. The applied voltage to the isolated dynode is developed electronically by a voltage to frequency converter coupled by an opto-isolator to a gain voltage divider circuit which cycles the applied voltage between two different voltage potentials tapped from the voltage divider string. The voltage to frequency converter is controlled by individual gain signals developed and stored during calibration of the camera for each photomultiplier.