| 摘要 |
PROBLEM TO BE SOLVED: To efficiently form an optimum image by changing a set condition such as a developing bias voltage or the irradiation light quantity of a photoreceptor and adopting a method by which image density can be quickly controlled to be the aimed image density. SOLUTION: This device is provided with a linear velocity switching part 1 switching the linear velocity of the photoreceptor, a fast concentration control part 2 controlling the set condition so that the toner concentration of a reference pattern becomes the fixed concentration fast and a slow concentration control part 3 controlling the set condition so that the toner concentration of the reference pattern formed on the photoreceptor slowly becomes the fixed concentration. Then, when the switching part 1 is actuated, the reference pattern is formed without relation to a prescribed interval and the toner concentration is controlled by actuating the control part 2. |
