US Patent 7649648 Duplex printer with motorized platen assemblies

A duplex printer includes a body defining one or more spaces in which respective ink cartridges can be placed. A pair of print engines is mounted within the body and a print media path is defined there-between. Each print engine includes at least one printhead coupled in fluid communication to the ink cartridges and is configured to eject ink supplied from the ink cartridges. A pair of print media trays is mounted, in a releasable manner, to either side of the body and each contains print media. Each print media tray includes a movable platen for supporting a stack of print media and a motorized mechanism configured to move the platen.