Patent ID: 7020405
Filing Date: 2006-03-28
Classification: G03G

Abstract:
1. An image forming device comprising: a photosensitive drum rotatable in a predetermined direction about an axis and having a peripheral surface on which an electrostatic latent image is formed; a driving unit; a drive signal generating unit that generates a drive signal to be applied to the driving unit, the driving unit rotating the photosensitive drum in response to the drive signal; a charging unit that is disposed in confrontation with the photosensitive drum and electrically charges the photosensitive drum; a charging bias applying unit that applies a charging bias to the charging unit; a developing agent bearing member that is disposed in confrontation with the photosensitive drum in a position further downstream than the charging unit with respect to the predetermined direction in which the photosensitive drum rotates, the developing agent bearing member forming a developed image on the photosensitive drum by applying developing agent on the electrostatic latent image on the photosensitive drum; a transfer unit that is disposed in confrontation with the photosensitive drum in a position further upstream than the charging unit with respect to the predetermined direction but further downstream than the developing agent bearing member, the transfer unit transferring the developed image on the photosensitive drum onto a recording medium; a control unit that controls the charging bias applying unit to terminate application of the charging bias to the charging unit at a time before rotations of the photosensitive drum stops completely by interrupting application of the drive signal from the drive signal generating unit to the driving unit, and controls a potential between the photosensitive drum and the developing agent bearing member so that a lesser amount of the developing agent on the developing agent bearing member adheres to the photosensitive drum before the photosensitive drum stops completely, and a transfer bias to the transfer unit, wherein when an area on the photosensitive drum opposite the transfer unit reaches a position opposite the charging unit resulting from the rotation of the photosensitive drum after a first predetermined time period, the control unit controls the transfer bias applying unit to switch the transfer bias at a transfer bias switching time that precedes the first predetermined time period from a time when application of the charging bias is stopped so that a lesser amount of the developing agent on the developing agent bearing member adheres to the photosensitive drum before the photosensitive drum stops completely.