Thermal printout density control

Abstract

Data records provided by thermal recording heads, including a plurality of clocked heating elements, are controlled in density by continually storing for each of such heating elements a present moment recording datum and further recording data including a one-clock-interval-old recording datum and a two-clock-interval-old recording datum for the particular heating element, and by continually generating for each heating element from the present moment recording datum to be recorded a first dot recording energization quantum and for each of the further dot recording data having been printed a dot recording energization pause and for each blank value of such further dot recording data a further dot recording energization quantum. This advantageously includes an insertion, for each one-clock-interval-old recording datum having been printed by the particular heating element, of an energization pause between a dot recording energization quantum corresponding to a blank value of the immediately preceding two-clock-interval-old recording datum and the then present moment dot recording energization datum. The heating elements are sequentially energized with dot recording quanta thus generated.