Patent ID: 8718532

Claim:
A color image forming apparatus for forming a color image on a printing medium, the color image forming apparatus comprising: a main body; a pick-up unit to pick up the printing medium; a paper tray part attachable and detachable with respect to the main body, which accommodates the printing medium, the paper tray part further including a pair of registration rollers which aligns a leading edge of the printing medium picked up by the pick-up unit; an image forming part included in the main body, which forms a color image on a printing medium, the image forming part including a transfer belt which transfers the printing medium, and a plurality of developing devices which are disposed in relation to the transfer belt and sequentially from a lower part to an upper part of the main body; a path provided within the main body that serves to move the printing medium in a direction; a reversing path provided within the main body that serves to reverse the direction of the printing medium on which an image is formed on a first surface thereof by the image forming part, the reversing path configured to allow the printing medium to pass through a portion of the paper tray part, and a sub-feeding part to feed a printing medium from outside of a casing and that supplies the printing medium to an interior of the casing, wherein the registration rollers are positioned along the path and the reversing path, wherein the paper tray part includes a feeding roller part which re-feeds the printing medium, being transferred via the reversing path and passing through the portion of the paper tray part, to the registration rollers, wherein the registration rollers and the feeding roller part included in the paper tray part move together with the paper tray part as a single unit, as the paper tray part is moved into or out of the main body, wherein the reversing path is configured to transfer the printing medium in a reverse direction of forming the color image sequentially by the plurality of developing devices, and wherein the feeding roller part included in the paper tray part transfers each of the printing medium passed through the reversing path and the printing medium supplied by the sub-feeding part to the registration rollers included in the paper tray part.