ELECTROMAGNETIC DRIVE ACTUATOR, MAGNETIZING DEVICE AND LIGHT AMOUNT ADJUSTER

PROBLEM TO BE SOLVED: To provide a small-sized and new type electromagnetic drive actuator and a magnetizing device, by which large torque is obtained by a small current, and also to provide a small-sized and new type light amount adjuster equipped with the electromagnetic drive actuator. SOLUTION: The N pole and the S pole are magnetized so that a magnetic field distribution on the surface of each permanent magnet (13a, 13b) is cyclic at a degree of 720/n in the circumferential direction, a pair of the N pole and the S pole exist in a range of one cycle, and when a width (angle) that either of the pair of poles occupies in the circumferential direction is k3, and a width (angle) that the other pole occupies in the circumferential direction is k4, an expression k3>k4 is satisfied. COPYRIGHT: (C)2005,JPO&NCIPI