Production of color proofs and printing plates
AssigneeMinnesota Mining and Manufacturing Company
InventorsRanjan C. Patel, John Souter
Life of this patent
Estimating the term…
Abstract
A color reproduction method is described using laser addressable thermal transfer donor elements which may be used to image both color proofing films and printing plates. Matched proofs and plates may be generated by direct digital address since identical transfer media are used in the respective imaging processes. In addition, each plate bears a resin image of a color that matches the color of the ink that will be used with that plate thus providing a convenient means of identification. In other words, the identity of each plate (i.e. whether it bears the y, m, c or k separation image) is immediately apparent by visual inspection, thus removing any risk of confusion and any need to provide individual plates with identification marks.
Claims16
A method of image reproduction comprising the steps of:
- (a) generating separate digital data sets representative of color separation images for a multicolor image;
- (b) providing a first laser thermal transfer donor element comprising a support having coated thereon one or more layers comprising an infrared absorber and a dispersion of a colorant in an oleophilic resin, said colorant matching the color of one of said color separation images;
- (c) assembling said first donor element in contact with a first receptor;
- (d) scanning said first donor element with a laser having an output modulated in accordance with the digital data set representative of the separation image whose color matches the colorant used in step (b);
- (e) transferring said one or more layers of said first donor element in areas struck by said laser to form an image on said first receptor;
- (f) providing a second laser thermal transfer donor element identical to said first laser thermal transfer donor;
- (g) assembling said second donor element in contact with a second receptor having a hydrophilic surface suitable for use in lithographic printing;
- (h) scanning said second donor element with said laser modulated in accordance with the same digital data set as used in step (d);
- (i) transferring said one or more layers in areas struck by said laser to form an image on said second receptor;
- and
- (j) repeating steps (b) through (i) at least once, wherein a different colorant is used on each repetition of step (b), the first receptor is used on each repetition of step (c), and a different hydrophilic receptor is used on each repetition of step (g).
Dependencies are inferred from the claim text.