| 摘要 |
PURPOSE:To obtain a stable reproduced picture even when enlarging the gradation of one picture element by preparing a table for correcting picture data so as to hold a set relation between a gradation data and a latent image potential based on the detected value of a surface potential for an electrostatic latent image formed at an image carrier. CONSTITUTION:A potential sensor 8 measures the potential of the latent image formed on a photosensitive object 2 by pulse width modulation. Afterwards, corresponding to the detected result of the potential sensor 8, a correcting data setting part 21 calculates the correcting data for correcting the picture data to be outputted from an LUT 17 and stores the correcting data in the LUT 17. At the time of picture recording, a switch 19 is changed over to the LUT 17 and the input picture data is corrected and inputted to a laser driving part 20. Then, the relation between the gradation of the picture data and the average potential is held constant. |
