| 摘要 |
PURPOSE:To read accurately information through a lens with low performance by providing a driving means which consists of an elastic member for supporting a projection lens so that it is displaceable in its optical-axis direction and at right angles to it and displaces the projection lens. CONSTITUTION:When the output of a detector 8 is applied to coils 103a-103c, forces generated by permanent magnets 104a and 104b in directions A and B operate on the coils 103a and 103b on a lens barrel 102 supported by the support member 107 consisting of at least two elastic wire bodies arranged in parallel while a plane containing the lens optical axis is interposed, so the projection lens 101 moves at right angles to and along an information track T. A force generated by a magnet 104c in a direction C operates on the coil 103c on an elevation memver 108 which supports a member 109 to move the projection lens 101 at right angles. Thus, the lens of simple constitution positions a light spot at one point on the information track accurately to perform focusing. |
