Ribbon feed with ink depletion compensation

摘要

Where the ribbon advance mechanism of a printer is driven by the motion of the print head carrier, ink in the ribbon will be differentially depleted depending upon the density of print. This varied depletion becomes a problem for printers capable of printing high density graphics images, particularly color filled images. In accordance with this invention, the printing density is monitored and when the printing density exceeds a predetermined value, the print head is caused to be moved an amount greater than that necessary to position the print head at a succeeding print position so as to thereby cause additional ink ribbon to be advanced and to avoid overprinting on areas of the ribbon where high density printing has occurred.