Patent ID: 7920819

Claim:
An image forming apparatus comprising: a fixing unit including a rotary heating member and a rotary pressure member forming a nip therebetween, the fixing unit operable to fix a toner image formed on a transfer medium by applying heat to the toner image while passing the transfer medium through the nip, wherein the fixing unit passes at least two types of transfer medium, one type being a stiff transfer medium whereas another type being a pliable transfer media; and a guide wall positioned immediately downstream of the fixing unit and on the side of the rotary heating member with respect to a boundary defined by the transfer medium passing the nip; a guide member positioned on the side of the rotary pressure member with respect to the boundary and face to face with the guide wall, the guide member and the guide wall cooperatively guiding the transfer medium discharged from the fixing unit; and a guide member positioning mechanism for shifting the guide member between a first position where the guide member is moved away from the guide wall and a second position where the guide member is moved closer to the guide wall than at the first position, the guide member positioning mechanism includes a biasing member capable of forcing the guide member toward the guide wall to shift the guide member between the first position and the second position, wherein the biasing force of the biasing member is so determined that when the stiff transfer medium is discharged from the fixing unit, interference of the stiff transfer medium with the guide member moves the guide member away from the guide wall to shift the guide member to the first position, and when the pliable transfer medium is discharged from the fixing unit, the guide member remains at the second position regardless of the interference of the pliable transfer medium with the guide member.