Error detection in a digital printer employing type wheels

摘要

A digital printer of the print wheel controlling type comprising a timing signal generator for developing type selection controlling signals ( alpha ) for selecting a desired type mounted on the print wheel, and a wheel round detection signal ( beta ) for indicating a complete one round of the print wheel. A print control circuit is provided for detecting whether the wheel round detection signal ( beta ) is developed next after the development of the type selection controlling signals ( alpha ) by a predetermined number. If the wheel round detection signal ( beta ) is not developed at a preselected timing, the print control circuit learns an erroneous printing operation, and functions to conduct a corrected printing operation.