Graphic Art Applications of Laser Thermal Printing

Abstract

Kodak and other companies use Laser Thermal Printing (LTP) for digital color proofing, computer to plate preparation, and other graphic art applications with highest quality results. This paper addresses the questions a) why does LTP work so well ? and b) what can we expect in the future ? The LTP process consists of focusing the beam of a diode laser onto a coating containing an infra red absorber and either a dye or a thermally sensitive reagent. The infrared dye absorbs the diode laser beam and converts the energy to heat, which causes the dye to transfer, or a chemical reaction in the coating. LTP images have very high resolution because the laser spot can be focused almost to the diffraction limit. Edges are very sharp because the temperature drop at the edge of the beam is steep. An important factor in the application of LTP to graphic arts is that all the amplification is electronic and the results are therefore predictable, reliable and robust. These are essential qualities that will determine how far the printing industry can change from a skilled art and craft to an automated and standardized process.