Patent ID: 8503104
Filing Date: 2013-08-06
Classification: G03B,H02K

Abstract:
1. A light amount adjustment device, comprising: a plurality of aperture blades configured to adjust an opening amount of an opening; a drive member configured to drive said aperture blades; a cam member configured to restrict an amount of movement of said aperture blades being driven by said drive member, into the opening; a holding member that is fixed to said cam member in a manner sandwiching said drive member and said aperture blades therebetween; and a motor mechanism that is gear-connected to said drive member and is configured to transmit a driving force to said drive member, wherein said motor mechanism includes a rotor, a stator, a first magnetic pole part, a second magnetic pole part, a first coil and a second coil, wherein said rotor is divided into a plurality of portions in a circumferential direction and alternately magnetized to different poles, wherein said stator is made of a soft magnetic material and formed integrally with said holding member, wherein said stator includes a support section, a first magnetic pole part and a second magnetic pole part, wherein said support section configured to rotatably support a rotary shaft of said rotor, wherein said first magnetic pole part is formed at a position different from a position of said support section in a direction to a rotational axis of said rotor, and extends toward an outer periphery of said rotor, wherein said second magnetic pole part is formed at a position different from the position of said support section in a direction to the rotational axis of said rotor, and extends toward the outer periphery of said rotor, wherein said first coil wound into a hollow-cylindrical shape, said first coil is inserted onto said first magnetic pole part from an extending end thereof, and wherein said second coil wound into a hollow-cylindrical shape, said second coil is inserted onto said second magnetic pole part from an extending end thereof.