Method and apparatus for determining the position of the printing medium in a high speed printer.

摘要

A high-speed printer (10) includes a rotatable platen (11) and a movable print carriage (18). The carriage includes a light-emitting diode (24) and a photo-detector (26) which scan the platen, as the carriage moves, looking for the edge of the paper. The light is transmitted to and from the platen by a pair of optical fiber bundles (32, 33) which are randomly interspersed at their forward end to produce a third optical fiber bundle (34).