Patent ID: 7138734

Claim:
A linear motor comprising a first member including a plurality of magnetic bodies around which a common coil is wound, and a second member in the form of a flat plate comprising a permanent magnet, wherein the plurality of magnetic bodies comprise first magnetic bodies and second magnetic bodies; the first magnetic body comprises a first magnetic pole tooth disposed on one side of the second member, and a second magnetic pole tooth disposed on the other side of the second member, the first and second magnetic pole teeth being opposed to each other to form a first gap therebetween; the second magnetic body comprises a first magnetic pole tooth disposed on said other side of the second member, and a second magnetic pole tooth disposed on said one side of the second member, the first and second magnetic pole teeth being opposed to each other to form a second gap therebetween; the first and second magnetic bodies are alternately disposed in a relative moving direction of the first and second members so that the second member relatively moves in the first and second gaps; at least one tooth of each set of said opposing first and second magnetic pole teeth of the first magnetic bodies and the second magnetic bodies has a step portion; and the width of the step portion in a direction perpendicular to the relative moving direction of the first and second members is smaller than the width of the permanent magnet in the same direction.