ACTUATOR FOR CAMERA

An actuator for cameras includes a carrier having a lens attached thereto and movable along an optical axis, a housing enclosing the carrier, at least one magnet mounted on the carrier and having k magnetic poles where k is a natural number equal to or larger than one, coils facing the magnet and disposed anterior or posterior along the optical axis, a Hall sensor assembly having m Hall sensors where m is a natural number equal to or larger than three, disposed along the optical axis, each of the m Hall sensors separated from one another by a first spacing, and an operational driver controlling the current applied to the coils in response to the signals from the Hall sensor assembly, in which the length of the magnetic pole is not less than the first spacing but not more than twice the first spacing.