Patent ID: 7542708

Claim:
An image forming apparatus, comprising: a photosensitive body on which surface an electrostatic latent image is formed; a developer which forms a toner image on the surface of the photosensitive body by developing the electrostatic latent image formed on the surface of the photosensitive body; a transfer unit which transfers the toner image formed on the surface of the photosensitive body onto a recording medium; recording medium carrying members which carry the recording medium to a nip region between the photosensitive body and the transfer unit; a transfer assist mechanism which presses the recording medium on the surface of the photosensitive body by adjusting a width where the recording medium presses the surface of the photosensitive body corresponding to the width of the recording medium; wherein the transfer assist mechanism includes a hinge shaft which is disposed in a transfer housing of the transfer unit in parallel to the width direction of the recording medium; a first blade holder having a first blade which is rotatably held by the hinge shaft by being formed in the width direction of the recording medium; a plurality of second blade holders having corresponding second blades which are rotatably held by the hinge shaft by being formed with the first blade holder in the width direction of the recording medium; first engaging grooves which are formed in the first blade holder and the plurality of second blade holders; second engaging grooves which are formed in the first blade holder and the plurality of second blade holders; a slide engaging member which is movably formed in the width direction of the recording medium by engaging the first engaging grooves and the second engaging grooves of the first blade holder and the first engaging grooves and the second engaging grooves of some of the second blade holders selected corresponding to the width of the recording medium; a driving mechanism including a motor which drives the first blade holder and some of the second blade holders selected corresponding to the width of the recording medium in the pressing direction of the recording medium; and a pressing range adjusting mechanism for adjusting the number of the second blade holders with the second engaging grooves engaged by the slide engaging member by moving the slide engaging member in the width direction of the recording medium corresponding to the width of the recording medium.