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. 23, 2009
Filed:
Feb. 05, 2007
Shuichi Kawana, Kyoto, JP;
Shuichi Kawana, Kyoto, JP;
Shimadzu Corporation, Kyoto, JP;
Abstract
An electron beam source device is provided in which the disconnection and deterioration of a filament of the electron beam source device can be accurately predicted and determined, so as to avoid an unnecessary resource waste and increase of cost due to a premature replacement of a still-functional filament in a conventional device. Additionally, disorganization caused by a sudden disconnection or by the subsequent recovery procedure when the deformation of the filament occurs can be avoided to, reduce the measuring time, the maintenance and management man-hour. A filament current is measured at all time through a filament current measuring circuit, and a ratio of the filament current when the light-on time is zero to the current filament current is calculated at all time through an operational circuit