Rotation angle detection device

• Main Authors: MITSUMATA CHIHARU, OKADA YASUYUKI, AIMUTA KYOHEI
• Format: Patent
• Language: Chinese; English
• Published: 13.04.2011
• Subjects: ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; MEASURING; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; PHYSICS; TARIFF METERING APPARATUS; TESTING

A rotation angle detection device comprises a magnet rotor, a magnetic sensor for detecting the direction of magnetic flux from the magnet rotor, a correction circuit, and an angle arithmetic circuit. The magnetic sensor has a bridge circuit (X) and a bridge circuit (Y) each of which is connected to four magnetoresistance effect elements. Each magnetoresistance effect element has a spinvalve-typehuge magnetoresistance effect film. The correction circuit calculates the difference (Vx - Vy) between the output voltage (Vx) of the bridge circuit (X) and the output voltage (Vy) of the bridge circuit (Y) and the sum (Vx + Vy) of the output voltage (Vx) of the bridge circuit (X) and the output voltage (Vy) of the bridge circuit (Y) and uniformizes the amplitudes of the difference and the sum. The angle arithmetic circuit obtains the rotation angle of the rotor by arctangent calculation from the (Vx - Vy)' signal and the (Vx + Vy)' signal both of which are outputted from the correction circuit and have the same ampli