Abstract: An automatic document feeder with a drive system that can efficiently handle double-side scanning and accommodate more than one timing sequence for sequentially picking individual sheets from a stack using only two motors—a pick motor and a media motor. The automatic document feeder includes a pickup unit with a pick roller, a set of de-skew rollers, a main media path configured to guide a media sheet from the pickup unit to a scanning region and from the scanning region to an output tray, and a switch-back path configured to guide the media sheet back into the main media path. The drive system is operable to provide a high-speed picking mode and a delayed picking mode. In the high-speed picking mode, the pickup unit is driven by the pick motor to pull a subsequent media sheet from a stack of media sheet as soon as a previously pulled media sheet has passed the pick roller.

Abstract: A temperature differential over a length of a fuser can result from a thermal load applied to the fuser by media having a dimension, corresponding to a longitudinal axis of the fuser, less then the length of the fuser. The temperature on regions of the surface of the fuser contacting the media is lower than on regions of the surface not contacting the media. With feedback used to control the fuser surface temperature near its center, the fuser surface temperature in regions not contacting the media can become hot enough to damage the fuser. With a heat pipe included in the fuser, heat flows from the higher temperature regions on the surface of the fuser to the lower temperature regions on the surface of the fuser, thereby reducing the peak magnitude of the fuser surface temperature and the magnitude of the temperature differential over the length of the fuser.