Patent ID: 6443606
Filing Date: 2002-09-03
Classification: F21S

Abstract:
A vehicle headlamp comprising:a light source; a reflector for reflecting light from said light source forward; a movable shade capable of shading part of light incident on said reflector from the light source; a shade driving unit for moving the movable shade between a first and a second position where an incident light shading quantity has different values, said shade driving unit including a solenoid and an elastic member for urging a movable iron core of the solenoid toward a non-excited position, and for operating to move said movable shade to said first position by displacing said movable iron core to an excited position when power is supplied to the coil of said solenoid and also to move said movable shade to said second position by displacing said movable iron core to said non-excited position when the supply of power to said coil is cut off; a positioning member for positioning said movable shade to said second position by butting against said movable shade when said movable shade moves to said second position; and a solenoid driving circuit for driving said solenoid, said solenoid driving circuit being configured to decreasingly provide current to the coil of the solenoid when power to the coil is cut off, thereby inducing an electromotive force across the coil such that the movable iron core is gradually de-excited to prevent the movable shade from strongly butting against the positioning member.