| 摘要 |
PURPOSE:To measure the rotary angle of a rotary body highly accurately without reducing the interval between a magnetic recording medium and magnetic resistor elements, by arranging a plurality of magnetic resistor elements at a pitch of 1/N (where N>=6) of the magnetic pattern pitch of the magnetic recording medium on the rotary body. CONSTITUTION:A magnetic drum 3 is provided with a magnetic recording medium having a magnetic pattern that is magnetized at a constant pitch lambda and fixed to a shaft 2 of a motor 1. Magnetic resistor elements 6 are formed on the surface of a substrate 5, which is fixed on a supporting table 4 that is further fixed on the housing of a rotary body. The elements 6 are made to face the recording medium on the outer surface of the drum with a specified interval 7 being provided. The three magnetic resistor elements 6 are arranged on the substrate 5 along the rotating direction of an arrow A of the magnetic drum 3 at a pitch of lambda/6. Since the three phase output signals, whose phases are 60 deg. apart, are obtained, the rotary angle of the rotary body can be measured highly accurately without reducing the interval 7. |
