Patent Document ID: 4829326
Application ID: 07093126
Patent Status: 1

Claim One:
1. In an electrostatic plotter system of the type that forms a composite color image by superimposing a second primary image of a second primary color over a first primary image of a first primary color formed on an image medium, where each primary image consists of image lines of dots, where the image lines are printed by a print head, where the image provided to the plotter system from an image source is in the form of virtual image data, with each image line of the virtual image in the from of NW binary data elements, where each primary image is formed by positioning the medium at a first position relative to a print head, printing a first image line on the medium. positioning the medium in a second position relative to the print head, and so on until NL image lines have been printed, a system for registering the second primary image to the first primary image formed at a first print head comprising: a second print head for forming a second primary image having NP styli, with NP greater than NL, with each styli for forming a dot on said image medium when activated, with the styli disposed in an elongate, substantially equidistant array positional substantially perpendicular to the direction of relative motion between said plotter head and said image medium, with the styli labeled S.sub.i, i=1,. .. , NP, and with S.sub.1 being the stylus on the first end of the print head and with S.sub.NP being the stylus on the second end of the print head; means for defining an active region of NA adjacent styli at said second print head with S.sub.A being a stylus on the first boundary of the active region and S.sub.A +NA being the stylus on the second boundary of the active region, with said active region for printing the dots in an image line of said second primary image; means for forming a first registration mark on said medium with said means for forming having a fixed lateral positon ralative to said print head; means, at said second print head, for sensing the lateral position of said first registration mark on said medium when said mark is positioned below said print head; and means, coupled to said sensing means and said second print head, for adjusting the value A to position the stylus S.sub.A a selected distance from said sensed first registration mark on the medium.