| 摘要 |
PURPOSE:To decrease inspecting man-hours and to improve good-product ratio, by evaluating a plurality of magnetoresistance effect elements formed on the same substrate, and making it possible to judge the quality before assembling into a magnetic head and an encoder. CONSTITUTION:A magnetoresistance effect MR element is fixed on a mounting stage 6 so that it is attached and removed. The stage 6 is attached on the upper end of a rotary shaft 8. An encoder 3, for measuring a rotary angle is attached to the intermediate part of the shaft 8. A computer 5 gives a command to a motor driver 9 so as to rotate a motor 2 from a reference position. The rotation is monitored with the encoder 3, and the rotation is stopped at a crossed position at Y at a right angle, to which the MR element is rotated by a specified angle. The element is further rotated by a minute angle beta. The computer gives a command to a power source 10 for a coil so as to change the magnitude of a magnetic field to a positive or negative side. A magnetism-resistance characteristic is measured with a resistance meter 4 at the same time. A measuring operator obtains the value of beta, at which hysteresis becomes the minimum value. This value is made to be an evaluated value beta0. In this way, the fluctuating state of a duty ratio of the square wave of the MR element in the manufacturing stage of the MR element can be evaluated beforehand.
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