JP2006243747A5 - - Google Patents

Claims (5)

A charging roller is provided so as to be close to the photosensitive drum so as to form a predetermined gap at least in a charging region and is rotatably provided, and a voltage obtained by superimposing an AC voltage on a DC constant voltage is applied to the charging roller. In the voltage setting method of the charging device for charging the photosensitive drum ,
The AC component of the voltage applied to the charging roller is set to have a peak-to-peak voltage value that is at least twice the charging start voltage value at the maximum gap among the predetermined gaps,
The maximum gap is a gap at a position where the largest gap amount is obtained at each position in the longitudinal direction of the charging roller at the closest portion between the surface of the photosensitive drum and the surface of the charging roller in the charging region. A voltage setting method for a charging device, wherein the voltage gap is a maximum gap that periodically appears while the photosensitive drum and the charging roller rotate . The average value of the gap at each position in the longitudinal direction and the short side direction of the charging roller in the charging region is 10 μm or more, and variation in the gap is 10 μm or more with respect to the average value. Voltage setting method for charging device. 3. The charging device voltage setting method according to claim 1, wherein the charging roller is an elastic roller. 4. The voltage setting method for a charging device according to claim 1, wherein the gap is formed by interposing a gap management member between the photosensitive drum and the charging roller. 5. 5. The charging device according to claim 1, wherein the charging roller is provided so that a portion in contact with the photosensitive drum in the charging region and a non-contact portion are mixed. 6. Voltage setting method.