Patent ID: 7122920
Filing Date: 2006-10-17
Classification: G02B,H02K

Abstract:
1. A motor comprising: a rotatable rotor having a cylindrical magnet which is divided into n portions in a circumferential direction to be alternately magnetized to different magnetic poles; a first coil disposed adjacent to the magnet in a direction of a rotary shaft of the rotor; a first outer magnetic pole portion which is excited by the first coil, which is disposed at a center portion of the first coil, and which is opposed to an outer circumferential surface of the magnet within a first predetermined angle range; a second outer magnetic pole portion which is excited by the first coil, which is adjacent to an outer circumference of the first coil, and which is opposed to the outer circumferential surface of the magnet; a first inner magnetic pole portion which is excited by the first coil, which is adjacent to the outer circumference of the first coil, and which is opposed to an inner circumferential surface of the magnet; a second coil which is adjacent to the magnet in the direction of the rotary shaft of the rotor and which is disposed on the substantially same plane as the first coil; a third outer magnetic pole portion which is excited by the second coil, which is disposed at a center portion of the second coil, and which is opposed to the outer circumferential surface of the magnet within a second predetermined angle range; a fourth outer magnetic pole portion which is excited by the second coil, which is adjacent to an outer circumference of the second coil, and which is opposed to the outer circumferential surface of the magnet; and a second inner magnetic pole portion which is excited by the second coil, which is adjacent to the outer circumference of the second coil, and which is opposed to the inner circumferential surface of the magnet.