Rotational angle detecting device

• Main Authors: MIZUTANI AKITOSHI, BAN TAKAO
• Format: Patent
• Language: English
• Published: 16.12.2004
• Edition: 7
• Subjects: ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; PHYSICS; TARIFF METERING APPARATUS; TESTING

In a rotational angle detecting device, an auxiliary magnet is disposed so as to surround a Hall element around the Z-axis, so that variation of offset magnetic flux is suppressed even when the position of the Hall element is displaced in the X-axis direction with respect to the auxiliary magnet. In addition, even when the fabrication position of the Hall element is displaced in the Y-axis direction of the auxiliary magnet, the variation of the offset magnetic flux is suppressed. By adjusting the dimension (the length in cylinder direction) in the Z-axis direction of the auxiliary magnet, the variation of the offset magnetic flux is suppressed even when the Hall element is displaced from the center of the auxiliary magnet in the Z-axis direction. That is, even when the position of the Hall element is displaced from the center of the auxiliary magnet in the three-dimensional direction, the displacement of the offset magnetic flux can be prevented, and thus reduction of the detection precision can be prevented.