Patent ID: 8290413

Claim:
An image forming apparatus comprising: an intermediate transfer belt rotatably stretched across a first plurality of roller members; a first image carrier arranged facing a front surface of the intermediate transfer belt; a first image forming unit that forms an image on the first image carrier; a primary transfer unit that primarily transfers the image formed on the first image carrier onto the intermediate transfer belt; a secondary transfer roller that is arranged facing the front surface of the intermediate transfer belt and secondarily transfers the image transferred on the intermediate transfer belt onto a recording medium; a second image carrier provided on an upstream side or a downstream side of a secondary transfer position in a recording medium conveying direction, the secondary transfer position being a position where an image is secondarily transferred from the intermediate transfer belt onto the recording medium; a second image forming unit that forms an image on the second image carrier; a direct transfer unit that directly transfers an image formed on the second image carrier onto the recording medium; a recording medium carriage belt that is rotatably stretched across a second plurality of roller members including the secondary transfer roller and supports and conveys the recording medium so as to pass the recording medium through a direct transfer position and the secondary transfer position, the direct transfer position being a position where the image is directly transferred from the second image carrier onto the recording medium; and a first displacement unit that displaces the secondary transfer roller in a movable manner between a contact position and a separate position, the contact position being a position where the recording medium carriage belt is brought into contact with the intermediate transfer belt and the separate position being a position where the recording medium carriage belt is separated from the intermediate transfer belt retracting from the contact position, wherein the first displacement unit includes a first shaft disposed through a longitudinal axis of the secondary transfer roller, opposite ends of the first shaft extending beyond a longitudinal length of the secondary transfer roller; a pair of elongated links, each of the elongated links supporting one of the opposite ends of the first shaft; a second shaft arranged substantially parallel to the first shaft; a pair of shaft guides separate from the elongated links, the pair of shaft guides including slotted holes elongated in a first direction, the first direction extending perpendicular to an axis of the first shaft toward the second shaft, each of the slotted holes supporting one of the opposite ends of the first shaft; and an eccentric gear coupled to the second shaft, the eccentric gear coupled to one of the pair of elongated links via a protrusion portion, and rotation of the eccentric gear displaces the first shaft in the first direction.