Patent attributes
The present invention is made to provide a pretransfer charging device, which allows (i) reduction of generation of discharge products such as ozone and nitroxide, (ii) excellent uniform charging, (iii) continuous stable charging for a long period of time, and (iv) restraint of distortion of a toner image. The pretransfer charging device includes (i) ion generation needles each provided face to face with an image carrier such as a photoconductor drum or an intermediating transfer belt, and (ii) a high-voltage power supply for applying a negative voltage to each of the ion generation needles. The voltage to be applied from the high-voltage power supply is not less than an ion production threshold voltage but is less than a corona discharge threshold voltage. With this, no corona discharge occurs but negative ions can be generated. This makes it possible to solve various problems caused due to the corona discharge.
