Development apparatus, image-forming apparatus and developing method using reverse polarity particles

摘要

A development apparatus and an image forming apparatus capable of minimizing deterioration of a carrier for a long time, even in a case of continuous formation of images of a smaller image area ratio. The charging of toner is assisted by using a developer composed of a mixture of toner and the carrier, to the surface of which is added a reverse polarity particle having a polarity reverse to that of a charged toner. Separation of the toner or reverse polarity particle of the developer prior to a process of development prevents the reverse polarity particle from being consumed in a developing area, whereby an effect thereof is maintained for a long time.