| 摘要 |
PURPOSE:To always secure a faithfully reproduced image by correcting the gammacharacteristic corresponding to secular change in the sensitivity characteristic of a photosensitive body and the electrification characteristic of developer, etc. CONSTITUTION:Prior to an actual copying operation, two types of reference toner images, low and high image densities, are formed. The concentration of each toner is detected. According to the toner image density M0, which is high, the highest density is controlled. At the same time, according to the ratio of the low toner image density M1 to the high toner image density M0 (M1/M0), the gamma characteristic in the low density area is corrected. |
