18916841. IMAGE FORMING APPARATUS (CANON KABUSHIKI KAISHA)

IMAGE FORMING APPARATUS

Organization Name

CANON KABUSHIKI KAISHA

Inventor(s)

Ryosuke Kosone of Chiba JP

IMAGE FORMING APPARATUS

This abstract first appeared for US patent application 18916841 titled 'IMAGE FORMING APPARATUS

Original Abstract Submitted

An image forming apparatus includes an image bearing member, a charging portion, a latent image forming portion, a developer bearing member for bearing and feeding a developer including toner and an external additive having the same polarity as a charging polarity of the toner, and a developing bias application portion for applying a developing bias in which a DC voltage is superposed with an AC voltage to the developer bearing member. In a continuous image forming job, the developing bias application portion applies the developing bias to the developer bearing member so that an absolute value of a difference between a predetermined charging potential and the DC voltage in a non-developing period is larger than an absolute value of that in a developing period and a peak-to-peak voltage of the AC voltage in the non-developing period is larger than that in the developing period.