Low profile side punch for internal drum imagesetter

摘要

A low profile side punch assembly (26) is provided to punch registration openings along the side edge of media (17) in an imagesetter (10). The side punch assembly (26) includes a punch actuator (34) having a scissors configuration to provide a low profile. The punch assembly is fixed to a side face (16) of the imagesetter (10). The punch assembly (26) can be located at any location along the side face (16). This location can also be subsequently adjusted if necessary. The location of the punch pin (60) is accurately set during manufacture with respect to the media surface of the imagesetter by a reference surface in the side face and by the side face of the drum. A drive mechanism (52) for the punch actuator (34) is also provided with a positive retraction of the actuator. The location of the punch pin (60) may also be sensed to prevent advancement of the media (17) before the punch pin (60) has been retracted.