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:
Feb. 08, 2005
Filed:
May. 13, 2004
Akira Tsukamoto, Saitama, JP;
Koichi Yokosawa, Kokubunji, JP;
Daisuke Suzuki, Kodaira, JP;
Akihiko Kandori, Kokubunji, JP;
Keiji Tsukada, Okayama, JP;
Akira Tsukamoto, Saitama, JP;
Koichi Yokosawa, Kokubunji, JP;
Daisuke Suzuki, Kodaira, JP;
Akihiko Kandori, Kokubunji, JP;
Keiji Tsukada, Okayama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A magnetic field measurement system for canceling an external field is provided, in which plurality of sensing magnetometers () for measuring a magnetic field signal in a direction perpendicular to the center axis of a cylindrical magnetic shield () are arranged in two dimensions on a plane parallel to the center axis and a reference magnetometer () for measuring the external field parallel to the center axis as a reference signal is disposed on a plane perpendicular to the plane parallel to the center axis. The reference signal multiplied by a specified factor is subtracted from a difference between signals from the adjacent sensing magnetometers (). The magnetic field measurement system allows measurement of an extremely weak magnetic field by efficiently canceling the external field.