| 摘要 |
PURPOSE:To attain high-speed tracking by using two focus evaluation generating circuits to apply focusing and using a 2nd focus evaluation value generating circuit in which the shape of focus evaluation is a slow mountainous form in applying the focusing just after restart. CONSTITUTION:Since the cutoff frequency of a 1st focus value generating circuit is higher than that of the 2nd focus evaluation value generating circuit, the focus evaluation being its output is steeper than that of the focus evaluation value from the 2nd focus value generating circuit. When the focusing by a 1st focus detection circuit 20 or the 2nd focus detection circuit 21 is finished, even when switch circuits 17, 19 are switched to any contact, the switch circuits 17, 19 are switched to the position to apply focusing by the output of the 2nd focus evaluation value generating circuit unconditionally when the focusing is restarted. Thus, the instability at restarting or malfunction is eliminated. |
