| 摘要 |
PURPOSE:To execute the correction when a subject sinks darkly by increasing the weight of the output of respective large area and small area level detecting circuits and controlling a diaphragm in accordance with the size of the contrast of the subject. CONSTITUTION:An image pick-up signal obtained through a diaphragm 1, a lens 2, an amplifying circuit and an A/D converter 5 is inputted to small area and large area level detecting circuits 11 and 12. The circuit 11 obtains the maximum value of the average value of the small area image pick-up level and outputs it to a contrast discriminating circuit 13 and a weight circuit 14. The circuit 12 obtains the average value of the image pick-up signal level of the whole of the image pick-up surface and outputs it to circuits 13 and 14. The circuit 13 obtains a ratio K of the output level of circuits 11 and 12 and outputs it to the circuit 14. The circuit 14 decides whether or not the difference in brightness is larger with the size of the K, and in case of K<4, namely, when the contrast is smaller, a weighting coefficient is 0, the diaphragm control is executed by the output of the circuit 11, and in case of K>6, namely, when the contrast is larger, the coefficient is m=1, and the diaphragm control is executed by the output of the circuit 12.
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