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. 26, 2012
Filed:
Oct. 11, 2006
Kazuo Mukaibatake, Kyoto, JP;
Daisuke Okumura, Kyoto, JP;
Kazuo Mukaibatake, Kyoto, JP;
Daisuke Okumura, Kyoto, JP;
Shimadzu Corporation, Kyoto, JP;
Abstract
The direct current bias voltage to be applied to the pre-filter provided in the previous stage of the quadrupole mass filter for selecting an ion according to the mass-to-charge ratio is changed in accordance with the mass-to-charge ratio of the target ion to be allowed to pass through, in order that the time period required for an ion to pass through the pre-filter is uniformed regardless of the mass-to-charge ratio, and simultaneously the phase of the oscillation of ions at the entrance of the quadrupole mass filter is also uniformed. In the range where the mass-to-charge ratio is larger than some degree, the ion's oscillation itself is small, and in addition, the ion's passage efficiency deteriorates rather than enhances, due to the potential barrier created by the voltage difference from the direct current bias voltage applied to the quadrupole mass filter.