| 摘要 |
PURPOSE: To reduce the number of the stopping and inspection times of a device and to improve working rate by performing a correction process adjusting the light quantity of a light emitting element several times so as to make the output of an image density sensor detecting the quantity of stuck developer on an image carrier constant. CONSTITUTION: During the period of the warm-up of a fixing unit 160, the light emitting diode of the image density sensor DS1 is light-emitted and the density in a state where toner does not stick on the image carrier 110 is detected, and the output voltage of a variable DC power source is fixed by adjusting the output voltage of a density detecting circuit 520 at this time. A similar process is performed on the image density sensor DS2 . Then, the latent image of a maximum density correcting test patch is written on the image carrier 110, and a change in the maximum density of a copy image is corrected, and furthermore gradation is corrected. In the case that the emitted light quantity is not decided at the time of deciding the emitted light quantity of the light emitting element of the image density sensors DS1 and DS2 so as to make sensor output constant, the same action is repeated several times, and after continuing an abnormal state several times, the device is stopped for the first time. |
