LENS SHUTTER DRIVING MECHANISM USED AS LENS DRIVING MECHANISM

摘要

PURPOSE:To reduce time lag from a second stroke to the releasing of a shutter by preliminarily travelling a main driving ring with the first stroke of a shutter releasing switch. CONSTITUTION:A releasing switch is pressed, and a control circuit 30 making a first contact point 31a completes a range-finding action. Then, after 15ms lapses, the control circuit 30 gives a normal rotating pulse to a motor 2, and revolves a main driving ring 4 to the left. When the circuit 30 confirms the turning ON of a switch 18, the motor is further, normally rotated, and the ring 4 is turned to the left just before a trigger arm 16b descends the inclined surface of the right side from the peak of a trapezoid cam 4d. Further, when a second contact point 31b is made, as well, the circuit 30 continuously, supplies the normal rotating pulse, turns a lens driving ring 5 to the left, and sends out a lens barrel, to wait for the stabilization of a focusing position. After the standby of the 15ms, the circuit 30 gives a reversal rotating pulse to the motor 2, turns the ring 4 to the right to be stopped at the focusing position. In the reversal rotating process of the ring 4, the arm 16b is run on the peak part of the cam 4d, a lever 16 is turned to the left centering a shaft 14 to open an aperture for exposing, and then, an AE circuit 32 is started.