| 摘要 |
PURPOSE:To achieve the simplification of constitution by once storing the maximum value of contrast signal and generating a coincidence signal. CONSTITUTION:A contrast detecting circuit 16 is connected to a comparator A3 via slope detecting circuit 17, peak pass pulse generating circuit 18, comparators A1, A2 and a lens extending direction detector 19 is connected to the comparator A3 via binary coding circuit 20, peak hold reset pulse generating circuit 21, analog switch S3 etc. The comparator A3 is connected to a light emitting diode D2 via transistor T1, buffer converter A4 etc. As a result of this, the maximum value of the contrast signal of the subject 13 extracted by the contrast detecting circuit 16 is once stored and when the contrast signal reaches the stored value again, a coincidence signal is generated and the light emitting diode D2 lights up on the focus matching position. |
