| 摘要 |
PURPOSE:To simply and highly accurately correct a shading by providing a division and average circuit, a peak value detecting circuit, the storing circuit of the average value of an area signal, the holding circuit of the peak value of the average value, a divider and a multiplier or the like. CONSTITUTION:When the shading is horizontally generated on the output signal of a preamplifier 3, for instance, according to the influence of a lens 1 or the like even though an object even in a face illumination is photographed, the division and average circuit 9 divides and averages the signal. Namely, the output signal of the amplifier 3 digitized in an A/D converter 8 is horizontally divided, the average value of the divided area signal is outputted and stored in the storing circuit 10. Then, the holding circuit 12 holds the peak value of the average value of the respective areas detected in the peak value detecting circuit 11 and the ratio of this value and the average value stored in the storing circuit 10 is calculated in the divider 13. The result is converted to an analog signal in a D/A converter 14 to have a shading correcting signal, multiply by the signal of the amplifier in the multiplier 6 and the shading can be simply and highly accurately corrected.
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