Signal circuit for an automatic focusing lens

摘要

A signal circuit for an automatic focusing lens is disclosed which has a displacement monitoring signal generator for generating a displacement monitoring signal representing the displacement of the lens by repeatedly turning on and off in accordance with the movement of the lens. The signal circuit is further provided with a limit signal generator for generating limit signals which represent that the lens has been moved to an infinity and a minimum-focusing-point. The displacement monitoring signal generator is connected to the limit signal generator and the output of the displacement monitoring signal is inhibited in accordance with the output of the limit signal, thereby preventing such a problem that the operation to move the lens will have been continued after the lens has been moved to the infinity or minimum-focusing-point.