Correction-lens-moving voice coil motor, anti-vibration device, interchangeable lens unit and optical apparatus

Abstract

A voice coil motor for moving a correction lens including a magnet unit having a pair of yokes and at least one permanent magnet for defining a magnetic gap, and a coil disposed in the magnetic gap. The permanent magnet having different magnetic poles adjacent to each other along the movement direction on a surface opposing the magnetic gap; the width of the permanent magnet in the movement direction being two times the width Wm of the magnetic poles; the width Wa of the coil in the movement direction being smaller than the width 2Wm of the permanent magnet; and the effective conductor width Wb of the coil, the magnetic pole width Wm of the permanent magnet and the longest movement distance St of the correction lens meeting the conditions of Wm=(Wb+St)×K, wherein K is a constant meeting 1<K≦1.5.