Patent ID: 8462452
Filing Date: 2013-06-11
Classification: G02B,H02K

Abstract:
1. An electromagnetic driving device, defining a center axis, comprising: a casing, having an inner compartment; a driven unit, accommodated in the inner compartment and moved along the center axis inside the casing, further having at least a friction part; an electromagnetic driving module, located inside the inner compartment at a position facing the driven unit, the module including a plurality of permanent magnets, at least one magnetic member and a coil, the magnetic member being mounted on the driven unit, one of the permanent magnets being positioned to face the magnetic member, the coil being mounted to surround the driven unit and located between the magnetic member and the permanent magnets; and a guiding mechanism, connected with the driven unit for guiding the driven unit to move along the center axis, the guiding mechanism contacting the friction part; wherein a friction force to hold still the driven unit, while a current is terminated to the coil, is generated at the friction part, during said contact, from a magnetic force of the one of the permanent magnets on the magnetic member.