| 摘要 |
PURPOSE:To increase the number of tone wedges and to obtain pictures having higher reproducibilities, by changing the size of picture element matrices with respect to only densities lower than a fixed level only. CONSTITUTION:Reflected light from an original 2 irradiated by a light source 1 is introduced to a photoelectric converter 3 and converted into electric signals. The output of the converter 3 is supplied to a comparator circuit 5 after it is converted into digital signals by an AD converter 4. Then the digital signal supplied to the comparator circuit 5 is compared with a reference level. If the digital signal is lower than the reference level as a result of the comparison, the size of the picture element matrix is changed in a direction along which the size becomes larger. Since the number of tone wedges increases when such adjustment is made, pictures having higher reproducibilities can be obtained.
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