Position detecting device of linear motor

摘要

The invention provides a device for improving the positioning accuracy of a linear motor. A stator 20 is designed to have two kinds of magnets with different surface magnetism arranged alternately and at uniform intervals along the linear moving direction. A moving member 30 is disposed movably in the linear direction while maintaining a uniform distance from the stator. A detector head 50 formed integrally with the moving member 30 detects the magnetic flux of the stator 20 and sends the data to a control unit 60. The fixed laser length measuring machine 100 irradiates a laser beam LB to a target 110 attached to the moving member, and using the reflected light, measures the distance between the laser length measuring machine and the target highly accurately. The position of the stator 20 used as the magnet scale and the highly accurate position data measured by the laser length measuring machine 100 are compared so as to compute the correction data corresponding to the position of the stator, and the computed value is stored in the storage unit 70 to be utilized for the positioning of the motor.