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:
Aug. 19, 2003
Filed:
Sep. 25, 2001
Hiroshi Kushihara, Nagano-ken, JP;
Tamagawa Seiki Kabushiki Kaisha, Nagano-Ken, JP;
Abstract
The present invention provides an automatic resolution changing method and circuit for use in a high-precision digital conversion of two-phase sinusoidal wave signals. The angular velocity (d&phgr;/dt) of the rotor obtained from the difference between these two-phase sinusoidal wave signals is integrated by a counter. Subsequently, digital conversion of the rotation angle (&thgr;) of the rotor with respect to the stator is performed, and a result of the digital conversion is outputted. At this time, in the case where the angular velocity (d&phgr;/dt) is equal to or higher than a first percentage of the follow-up speed at the current resolution of the counter, the resolution of the counter is reduced. Further, in the case where the angular velocity (d&phgr;/dt) is equal to or lower than a second percentage of the follow-up speed at the current resolution of the counter, the resolution of the counter is increased.