Duplexing module for printer

This invention relates to methods and apparatus for efficiently moving print media to enable printing on both sides of the media. Printing on both sides of the media is known as duplex printing. A duplexing module that is attachable to a printer that has a simplex media-handling system. The duplexing module is used in conjunction with the simplex system to carry out the print media handling (flipping) that is required for duplex printing. The module includes a single drive roller and an entry guide. The printer feed roller moves the printed media sheet along the entry guide to the drive roller of the duplexing module. The duplexing module includes an exit guide that extends between the drive roller and the feed roller. The print media (having one side printed) moves with the rotated drive roller until it reaches the exit guide. The printed side of the print media is thus directed against the feed roller of the printer so that the opposite side of the media is presented for printing.