| 摘要 |
PURPOSE:To set image quality at the time of correcting gradation to be satisfactory by permitting a sensor to measure the density of a specified gradation pattern formed on a photosensitive drum and controlling the inclination of LUT data. CONSTITUTION:The specified pattern formed on an image carrying body is gradation-controlled in accordance with density which a density detection means detects. The luminance signal of an image is obtained in CCD 21 and the luminance signal is converted into a digital luminance signal by an A/D conversion circuit 22. The sensitivity variance of respective CCD elements is corrected by a shading circuit 23, and the corrected luminance signal is converted in LUT for gradation correction 25 so that original image density agrees with the output image in correspondence with the theta characteristic of a printer at the time of initialization. A gradation control means 28 controls the conversion of LUT 25. Thus, the deterioration of image quality can be improved and the satisfactory image can be obtained. |
