| 摘要 |
PURPOSE:To prevent the completion of a focusing operation before a lens reaches a focusing location by monitoring whether the changed amount of a focus evaluation value in accordance with a diaphragm operation exceeds a prescribed value or not. CONSTITUTION:A diaphragm control circuit 81 transmits a diaphragm completion signal TG to a fifth comparator 83 when the diaphragm of prescribed amount is completed by an optical diaphragm mechanism 82. This fifth comparator 83 immediately monitors whether the difference of the focus evaluation value at the time of a focus operation completion which is stored in a fourth memory 11, the latest focus evaluation value obtained also after a focusing operation completion and the latest focus evaluation value exceeds a third threshold or not when the signal TG is inputted. The diaphragm of prescribed amount is performed when the difference exceeds the third threshold or just after focusing operation is completed, and when the rise width of the focus evaluation value by this disphragm is so large as it exceeds the third threshold, a non-focus signal NS showing that the lens location does not reach the focusing location is outputted to a focus motor control circuit 110 and the focus motor control circuit 110 performs the focusing operation again from the beginning. |
