Color change system for multicolor strip chart recorders

Abstract

An improvement is provided for printer such as the dot matrix or thermal type, in which the printhead is stepped across the paper over a multicolor ribbon supplied from a pivotally mounted cartridge and transported through a plane between the line of traverse of the printhead and the surface of the paper. The ribbon is guided by guiding surfaces positioned on each side of the printhead, close to the printhead, and mounted to move with the printhead across the paper so that the guide surfaces will guide the path the ribbon takes to one which passes between the printhead and the paper with the guide being moveable in steps in a direction normal to the traverse of the printhead and parallel to the plane of the ribbon so as to position a selected color band of the ribbon under the printhead to select the color to be printed as the printhead traverses the paper. The ribbon cartridge is free to pivot in response to movement of the ribbon guide and/or the printhead so as to accommodate the different positions of the ribbon with respect to the printhead, as determined by the ribbon guide and the different positions of the printhead with respect to the paper.