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:
Dec. 05, 2000
Filed:
Aug. 28, 1998
Minoru Sakairi, Tokorozawa, JP;
Tadao Mimura, Hitachinaka, JP;
Toshihiro Ishizuka, Hitachinaka, JP;
Masaru Tomioka, Hitachinaka, JP;
Yasuaki Takada, Kodaira, JP;
Takayuki Nabeshima, Kokubunji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Disclosed is an ion trap mass spectrometer improved to obtain a high sensitivity without the lowering of resolution. By fitting a mesh electrode to an aperture (an ion sampling aperture or an ion extracting aperture) made in endcap electrodes constituting an ion trap mass analysis region, a radio frequency electric field in the mass analysis region is not disturbed even if the diameter of the aperture is set to a large value to heighten ion transmission efficiency. By fitting a shield electrode for preventing collision of ions with an insulated ring constituting an outer wall of the mass analysis region, charging up of the insulated ring is prevented to improve stability of detection signals. Furthermore, by arranging a shield member for shielding stray charged particles detouring through the circumference of the mass analysis region to approach an ion detector, generation of noises based on these stray charged particles is prevented.