| 摘要 |
PROBLEM TO BE SOLVED: To prevent the lowering of the calibrating accuracy of a density sensor caused by the dispersion of the foundation density of an intermediate transfer drum. SOLUTION: An NV(non-volatile) RAM10 in which the substrate density data V0 of the intermediate transfer drum 5 is stored in mounted in the drum 5. In the case of calibrating the density sensor 9, light quantity A0h being the initial light quantity for calibrating a sensor is radiated, and the density Vmes of the drum 5 is measured. Next, a main CPU reads out the data V0 from the NVRAM10 and compares it with the density Vmes . In the case of Vmes =V0 , the light quantity A0h is set as the irradiating light quantity for the density sensor at the time of controlling the image density. In the case of Vmes <V0 or Vmes >V0 , the irradiating light quantity is added or subtracted by 1h until the sensor output Vmes reaches V0 , then the light quantity in the case of Vmes = V0 is set as the irradiating light quantity for the density sensor at the time of controlling the image density. |
