Patent ID: 6412991
Filing Date: 2002-07-02
Classification: B41J

Abstract:
A printer for printing images on a substrate, comprising a rotatable platen for receiving and moving a substrate therewith; a print head adjacent the platen and selectively operable to print images on the substrate; a movable web with a series of frames of different colors of transferable material arranged in a repeated sequence, said web having discrete index marks thereon indicating boundaries between adjacent frames, the discrete index marks being arranged in a series of a plurality of separately identifiable discrete and adjacent index marks along a line extending in a direction laterally across the web; a sensor for sensing and identifying the index marks as the web moves as guided by the platen and a controller; said controller receiving signals indicating the velocity of the web passing through the printer, and the sensor sensing the time for passage of selected ones of the index marks indicating boundaries correlated with the velocity of the web, to determine the length between selected boundaries on the ribbon, the controller determining the web stretch and panel length variation by comparing the determined length to a nominal length between the same selected boundaries.