LINEAR ELECTROMAGNETIC DRIVING APPARATUS AND USE OF SAME FOR LENS ADJUSTMENT

摘要

A linear electromagnetic driving apparatus includes a substantially rectangular tube-shaped magnetic yoke comprised of outer and inner frame plates spaced apart to form a gap with at least one magnet secured to an outer or inner frame plate to generate magnetic flux. A bobbin supporting a coil which extends in a direction parallel to the longitudinal axis of the magnetic yoke is positioned in the gap. A driven member is secured to and coaxial with the bobbin and has openings to receive the inner frame plates of the yoke such that when the coil is energized to move the bobbin in the gap, the inner frame plates extend into and through the bobbin and into and through the openings of the driven member. A fixed shaft extends parallel to the longitudinal axis of the yoke; and a bearing secured to the bobbin structure and extending outwardly therefrom receives and is slidable on the fixed shaft. At least one of the corners formed on the rectangular tube-shaped yoke is cut out to define an open portion through which the bearing passes so as to be unobstructed as the bobbin slides within the yoke.