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:
Oct. 20, 1998
Filed:
Apr. 19, 1996
Seiko Instruments Inc., , JP;
Abstract
A superconducting loop is formed by two Josephson junctions connected to both ends of a washer coil which serves also as a pick-up coil. The washer coil which is a magnetic field detection portion is constituted by two coils, i.e., a coil having a radius r.sub.1 and a number of turns n.sub.1 and a coil having a radius r.sub.2 and a number of turns n.sub.2 which are in the form of concentric circular loops. The two coils are coupled in opposite directions and are designed so that effective areas n.sub.1 .pi.r.sub.1.sup.2 and n.sub.2 .pi.r.sub.2.sup.2 are equal to each other. Since a magnetic field is directly detected by the washer coil, sensitivity to a magnetic field is enhanced. This makes it possible to obtain sufficient sensitivity to a magnetic field even if the area of the magnetic field detection portion is reduced to improve spatial resolution. It is, therefore, possible to realize a radial differential SQUID magnetic flux meter which has good spatial resolution and coil balance and which is suitable for mass production.