| 摘要 |
PURPOSE:To adjust or control the picture quality easily in a wide range, by charging the one-pack developer by using a power source for charge injection which applies voltage in pulse form, and controlling the interval, width or voltage of the pulse voltage to control the charging of the developer in distribution. CONSTITUTION:A conductive sleeve 1 attracts a one-pack magnetic toner 3 supplied from a toner supply device 2 by means of a magnet 4 provided inside, and conveys it along the rotation to contact with a photosensitive drum 5 carrying electrostatic latent image to develop. A developing bias power source 6 applies a specified bias voltage to the sleeve 1. A doctor blade electrode 7 adjusts the volume of the magnetic toner 3 on the sleeve 1, while a voltage is applied from a power source for charge injection 8 to inject an electric charge to the magnetic toner 3 to charge it. A pulse power source is used for this power source for charge injection 8 so as to continuously adjust the pulse non-applied time and applied time. By this adjustment, further, the constitution ratio of charged toner and non-charged toner provided on the magnetic toner 3 on the sleeve 1 is continuously varied, so that the charge volume and charge distribution of the toner may be changed. |
