Abstract: A backup roller is formed by a member having a rotational axis and a circumferential region around which a plurality of teeth are arranged. Each tooth of the plurality of teeth has a tip end extending in a direction away from the rotational axis. When the backup roller is rotated the tip end of each of the plurality of teeth sequentially extends toward the rotational axis of a drive roller at an angle non-orthogonal to the rotational axis of the drive roller.

Abstract: An open jam-door sensor having a peripheral device such as a printer including a substantially C-shaped feed path, the C-shaped feed path defining an inner guide and an outer guide, the outer guide being connected to the peripheral device. A media sensor for detecting type of media in the device is disposed on one of said guide opposite a reflective portion disposed on the other of said guides. The media sensor also being used to detect when the outer guide is in an open position and causing a processor to inhibit device operations, such as printing.