| 摘要 |
PROBLEM TO BE SOLVED: To provide an image that roughness in a highlighted part is prevented, sufficient image density is obtained and any defect is not caused by abnormal discharge by applying appropriate developing bias. SOLUTION: Relating to the device, BP bias consisting of a stopped part and an oscillating part is applied as the developing bias. Concerning pulse peak voltage of the oscillating part, the peak voltage (time Tg) in a direction when toner is flown to a photoreceptor is designated to be 900 V from potential difference with the stopped part (-400 V) and peak voltage (time Tb) in a direction returning the toner to a developing sleeve is designated to be 800 V from potential difference with the stopped part. Effective center voltage of the BP bias is approximately -417 V, potential difference Vb between the effective center voltage value and peak voltage in the direction flying to the photoreceptor drum is 883 V, potential difference Vb between peak voltage in the direction of returning to the developing sleeve is 817 V, the Vg is made greater than Vb and more toner is oscillated localized to the photoreceptor drum side.
|
