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. 19, 2010
Filed:
Apr. 26, 2007
Takashi Yoshida, Tokyo, JP;
Masaru Suzuki, Tokyo, JP;
Katsumi Kakuta, Tokyo, JP;
Asahi Kasei EMD Corporation, Tokyo, JP;
Abstract
The present invention relates to a position detecting device capable of canceling an error due to looseness in a vertical direction and of eliminating variation in temperature characteristics by calculating a ratio between output voltages of a plurality of Hall elements. Assuming that the Hall voltage Vheof a Hall element becomes A·K·Bhe(A is the amplification factor of a preamplifier, K is a constant, and Bheis the magnetic flux density the Hall element receives), then a PI regulator automatically adjusts the bias point of the PI output by feedback control in such a manner that A·K·BheVref=AGND (=0) holds. The Hall voltage Vheof the Hall element after amplification becomes A·K·Bhe. Since K=−Vref/A·Bhe, the Hall voltage Vheof the Hall element is given by −Vref·Bhe/Bhe