| 摘要 |
PURPOSE:To easily make a proper density correction for any density contract by accessing the 1st and the 2nd storage parts stored with adjustment quantities according to the maximum, minimum, or deviation value of image density detection values of an original. CONSTITUTION:A photodetecting element detects the maximum and minimum values of the image density of the original through maximum and minimum sample and hold circuits 14 and 15, an A/D converter 16, etc. Then, the 1st and the 2nd storage parts of an ROM20 are accessed through a CPU20 according to the maximum or minimum value, or the deviation between the maximum and minimum values and a CPU18 calculates an adjustment quantity on the basis of those pieces of function information on the background part and contrast of the original. Then, a lamp 2 for original exposure is controlled through a phase control circuit 10 on the basis of the arithmetic result to make a proper density correction automatically and easily at a high speed for any density contrast of the original. |
