Title:
MAGNETIC SENSOR AND MOTOR EMPLOYING IT
Document Type and Number:
Japanese Patent JP3490783
Kind Code:
B2
Abstract:
PURPOSE: To enhance accuracy in the detection of arbitrary phase shift and magnetic field by providing a plurality of magnetic circuit pieces having forward end parts spaced apart by a distance corresponding to an angle based on a predetermined phase shift of a detection signal.
CONSTITUTION: A Hall ICfH1 has yokes b1, c1 arranged on the opposite sides of an arbitrary one of pole areas 25-28 such that a magnetic flux can flow in. A magnetic ring 24 is fixed to the rotary shaft of a rotor or a permanent magnet such that the radially outward pole of a magnetic ring 24 has the same polarity as that of the permanent magnet. Consequently, the magnetic ring 24 rotates in synchronism with the rotor and a detection signal being outputted from a magnetic detection element when the flux from a moving field flows into one magnetic circuit piece is shifted by an interval, corresponding to the distance between the forward end parts of respective magnetic circuit pieces corresponding to the angle based on a predetermined amount of phase shift, from a detection signal outputted from the magnetic detection element when the flux from other magnetic circuit piece flows in. This structure enhances accuracy in the detection of arbitrary phase and field.
Inventors:
Toshiaki Murakami
Application Number:
JP25336394A
Publication Date:
January 26, 2004
Filing Date:
October 19, 1994
Export Citation:
Assignee:
Nidec Shibaura Corporation
International Classes:
G01B7/30; G01B7/00; G01D5/245; H02K29/08; H02P6/06; H02P6/08; H02P6/16; H02P6/17; (IPC1-7): H02P6/16; G01B7/30; G01D5/245; H02K29/08
Domestic Patent References:
| JP6284667A | ||||
| JP5176514A | ||||
| JP5644584Y2 |