Patent ID: 7265460

Claim:
A position detecting device of a linear motor which is built into the linear motor, comprising: a stator having two kinds of magnets with different surface magnetism arranged alternately and at uniform intervals along a linear moving direction; a coil, which is a moving member, disposed movably in the linear direction while maintaining a uniform distance from the surface of the magnets constituting the stator; a detector for detecting the magnetic flux of the magnets; a position detecting circuit enabling the detector to detect position; a measuring device for measuring the position of the stator used as a magnet scale for correcting the position detecting circuit and for measuring the variation of arrangement of the magnets or sizes of the magnet members; a storage unit for storing a correction data obtained by comparing the stator position and the result of measurement of the measuring device; and a control unit for correcting the detection position based on the correction data stored in advance when carrying out positioning of the moving member.