Abstract: A bidirectional dot-matrix printer compensates for dislocations of the location of the last print clock with printed information on a printed line by producing at least one further print clock after the end of the printing information, and initiating breaking of the printer carriage after such dummy print clocks. During movement of the print head in the reverse direction on the subsequent line, the dummy print clocks are taken into consideration before initiating print clocks which are coincident with printed information.

Abstract: A method and apparatus for tolerance compensation in matrix printing devices. A time duration is defined between the edge of a scan clock period formed by sensing motion of a printer carriage and a criterion formed at a start of a printing line. The time duration is identified in a measuring operation executed before the actual printing event and is compared to an upper and to a lower time threshold. If the time duration is below the lower time threshold or above the upper threshold, an output signal is emitted which delays a start of the print clock generation at a beginning of the printing line for the following actual print event.