Characteristics of Laser Dye Transfer Printing (I)

— Continuous Tone Printing —

Abstract

Tone reproduction in laser thermal transfer printing using dye sublimation type medium at high resolution was investigated. With this printing method, a laser is used as the heat source instead of a thermal head. As the laser beam can be focused to 2.8 microns in diameter, a high resolution image can be obtained by laser dye transfer printing.
In this paper, an experimental printing system that enables production of precise images by pulse width modulation was developed, and we evaluated the characteristics of continuous tone reproduction under various printing conditions such as pulse width, laser power and pulse cycle. Printing energy to obtain an image having an optical density of 1.0 is about 0.9 J/cm², and it is shown that there is little reciprocity law failure in this printing. The possibility of continuous tone printing at a high resolution was indicated, and we have obtained printed continuous tone image samples having a resolution over 3000 dpi.