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:
Apr. 18, 1989
Filed:
Jun. 30, 1987
Masayuki Uda, Tokyo, JP;
Yukio Tomioka, Tokyo, JP;
Chikara Kouno, Tokyo, JP;
Hiroshi Ishida, Kanagawa, JP;
Yukio Yamauchi, Kanagawa, JP;
Rikagaku Kenkyujyo, Tokyo, JP;
Abstract
A photoelectron counter in an open detection chamber in which photoelectrons emitted from a solid surface by a photon irradiation energy are counted, is arranged so as to suppress background noise which produces a false count rate due to photoelectrons which are emitted from solid surfaces outside the subject when scattered rays have reached and irradiated the same surface. The counter uses one or more of options including a film or coating formed with a thickness which is less than several .mu.m thickness on parts which are subject to scattered rays incident from the subject, a ray screen for interrupting scattered rays from entering into the detection chamber and/or a center guard provided at the front part of the detector to enable nearby measurement and while interrupting scattered rays.