US 6,981,807 B2
Electromagnetic drive device and light quantity adjustment device using the same
Hiroaki Naganuma, Kofu (Japan); and Tetsuyuki Tohyama, Yamanashi-ken (Japan)
Assigned to Nisca Corporation, Yamanashi-Ken (Japan)
Filed on Mar. 16, 2004, as Appl. No. 10/800,729.
Claims priority of application No. 2003-132024 (JP), filed on May 09, 2003.
Prior Publication US 2004/0223755 A1, Nov. 11, 2004
Int. Cl. G03B 9/08 (2006.01); H02K 33/00 (2006.01)
U.S. Cl. 396—463 5 Claims
OG exemplary drawing
 
1. An electromagnetic drive device comprising:
a coil frame with a hollow tubular shape including two bobbin members separated and joined perpendicular to an axial direction thereof,
a magnet rotor having a rotational shaft and disposed in the coil frame to be rotatable through the rotational shaft,
a transmission arm attached to the rotational shaft for transmitting a rotation of the magnet rotor to an outside of the coil frame, said transmission arm extending substantially perpendicular to the rotational shaft,
a coil wound around an outer periphery of the coil frame, and
an opening formed in one of the bobbin members in a peripheral side surface different from portions contacting the other of the bobbin members so that the transmission arm protrudes to an outside through the opening.