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. 24, 2003
Filed:
Apr. 11, 2002
Other;
Abstract
An outer cylinder having patterns of open windows of first to fourth channels is formed of a magnetic-shielding or antimagnetic substance. An inner cylinder is inserted in the outer cylinder, is formed of a magnetic substance and has patterns of nonmagnetic windows of the first to fourth channels. First to fourth coils excitable by A.C. are provided for the first to fourth channels. For each of the channels, the pattern of the open window in the outer cylinder and the pattern of the nonmagnetic window in the inner cylinder are arranged to overlap with each other. Arrangement of the windows in the channels is set such that: degree of overlap between the pattern of the open window and the pattern of the nonmagnetic window in each of the channels varies in accordance with a variation in a relative rotational position to be detected; a variation in the degree of overlap in the second channel presents a differential characteristic relative to a variation in the degree of overlap in the first channel; a variation in the degree of overlap in the fourth channel presents a differential characteristic relative to a variation in the degree of overlap in the third channel; and variations in the third and fourth channels present a predetermined difference from variations in the first and second channels.