Image forming apparatus having cleaning section for removing residual toner on intermediate transfer belt

摘要

An image forming apparatus (1) includes an image forming section (12), an intermediate transfer belt (125), a drive roller (125A), a secondary transfer roller (210), a brush section (80), a cleaning device (70), a power supply device (81), and a ground portion (82). The brush section (80) is disposed at a location downstream of the secondary transfer roller (210) in a direction of travel of the intermediate transfer belt (125) and facing the drive roller (125A) with the intermediate transfer belt (125) in between. A potential difference is applied between the brush section (80) and the secondary transfer roller (210) by the power supply device (81) and the ground portion (82), so that an electric current having the same polarity as a normal charge polarity flows from the brush section (80) through the drive roller (125A) to the secondary transfer roller (210).

主权项

1. An image forming apparatus comprising:
an image forming section including a photosensitive drum and configured to form a toner image on the photosensitive drum; an intermediate transfer belt mounted around a drive roller and a driven roller and configured to travel in an endless path between the drive roller and the driven roller; a primary transfer roller disposed at a location facing the photosensitive drum with the intermediate transfer belt in between and configured to transfer the toner image formed on the photosensitive drum to an outer peripheral surface of the intermediate transfer belt; a secondary transfer roller disposed at a location facing the drive roller with the intermediate transfer belt in between and configured to transfer the toner image formed, at a nip between the secondary transfer roller and the drive roller, on the outer peripheral surface of the intermediate transfer belt to a recording paper sheet; a charging member disposed at a location downstream of the secondary transfer roller in a direction of travel of the intermediate transfer belt and facing the drive roller with the intermediate transfer belt in between, the charging member being configured to charge residual toner remaining on the outer peripheral surface of the intermediate transfer belt to a normal charge polarity; a cleaning section including a fur brush disposed at a location downstream of the charging member in the direction of travel of the intermediate transfer belt and facing the driven roller with the intermediate transfer belt in between, the fur brush being in contact with the outer peripheral surface of the intermediate transfer belt and configured to electrically attract the residual toner remaining on the outer peripheral surface of the intermediate transfer belt to collect the residual toner; and a potential difference applying section including a power supply device configured to apply a bias to either one of the charging member and the secondary transfer roller and a ground portion configured to ground the other of the charging member and the secondary transfer roller, the potential difference applying section being configured to apply a potential difference between the charging member and the secondary transfer roller to generate an electric current flowing from the charging member through the drive roller to the secondary transfer roller and having the same polarity as the normal charge polarity.