Abstract: A predetermined window height at least three times the height of the normal printed characters can be printed in a single horizontal sweep of the printhead across the page. A page of character oriented data is first sorted vertically; the data is then sequentially processed into a "print window" of horizontally sorted characters until a character is reached that will not fit within the current print window. The symbolic data in the print window is converted into bit mapped image data only slightly in advance of the current printhead position. The average throughout is increased by permitting the velocity of the printhead to vary as a function of the complexity of the image formation process. For a thermal process, this is accompanied by an appropriate adjustment in the current passing through the activated printhead electrodes. The vertical positioning of the pixels within the print window is varied to better distribute head wear.

Abstract: A printer of the daisywheel type in which the existence of a carriage control signal and a printwheel control signal operate inhibiting apparatus for a control signal otherwise gated to a paper feed operator.