| 摘要 |
PURPOSE:To execute optimum density correction by making the fluctuation width of a copying density with respect to a change in the correcting quantity of a density large in the case of a dark original and small in the case of a bright original, in a copying machine for the exclusive use of automatic density control. CONSTITUTION:A microcomputer sets the illuminating quantity of an illuminating lamp at an intermediate value, allows the lamp to illuminate, and samples reflected light from the leading edge part of the original in a short time by a light receiving sensor, to calculate the average value of the received light quantity of the sampling. In the case of the dark original, the average value corresponds to that of a newspaper. On the other hand, a density correcting key is set at any value by a user. In the case of the dark original, programing is executed so as to make the fluctuation width of the copying density with respect to the change in the density correcting quantity large and when a thin density correction is executed, a copied image is moderately light and dark when a thick density correction is executed. Moreover, in the case of the bright original, the fluctuation width of the copying density with the change in the density correcting quantity is small and a difference between thinness and thickness is made small. |
