Method for detecting failure of a paper detector in a roll paper printer, and roll paper printer having control for detecting failure of a paper detector

摘要

The roll paper printer of the subject invention has a control to detect failure of a paper detector in accordance with a method for detecting such failure. The printer 1 is constructed so that the paper transportation path is open when the cover 3 to the roll paper compartment 10 is open and includes a paper detector 40 and a control unit 30 to determine if the paper detector 40 is faulty. A failure warning is provided by a warning indicator 7(S7, 8) to indicate failure of the paper detector 40 when the cover 3 has been open continuously for at least a first set time (S6) and the output state of the paper detector 40 has not changed even once to a no-paper state within the first set time. Preferably, the printing operation of the printer 1 is disabled upon determining that the paper detector 40 is faulty to permit replacement of the paper detector. Problems attributable to paper detector failure, such as soiling the platen with ink can thus be prevented.