LENS FOCAL POINT DISTANCE ADJUSTING DEVICE HAVING PIEZO-ELECTRIC THRUST STRUCTURE

摘要

The present invention relates to a focal distance adjusting module of a lens having a piezoelectric thrust structure, which makes a lens barrel perform inertial movement along an optical axis by a forward and backward operation of a thrust rod according to extension and contraction of a piezoelectric body. The present invention is configured in a form of arranging the piezoelectric thrust structure for promoting linear movement of the lens barrel between an inner wall of a base and an outer wall of the lens barrel housed in the base, facing each other. The piezoelectric thrust structure includes a piezoelectric thrust part having the piezoelectric body extended and contracted in a longitudinal direction by an electric field caused by supplying current and the thrust rod fixed to be stacked on the piezoelectric body to move backward and forward in a longitudinal direction parallel with an optical axis by the extension and contraction of the piezoelectric body; a guide promoting a biaxial pre-loaded support of the barrel supported with pre-load by the piezoelectric thrust part; and a magnetic pre-load part providing a magnetic pre-load according to the biaxial pre-loaded support of the barrel via the thrust rod of the piezoelectric thrust part and the guide. The lens barrel biaxially pre-loaded in the thrust rod of the piezoelectric thrust part and the guide by the magnetic pre-load is configured to move linearly along the optical axis by an inertial movement operation due to the backward and forward operation of the thrust rod.