High Quality Printing Technology of the Thermal Dye Transfer Printer

Abstract

A video printer using thermal dye transfer method is suitable for high quality printing. Recently this type of video printers is faster in printing time and lower cost, so there appears some problems about heat regeneration and optical density gap called ghost. Especially the ghost appears in the edge of vertical bands of high density, because of change of current rush to the thermal head. Heat regeneration in the thermal head makes a color tailing behind of high-density printing.
For ghost problem, we have investigated the line resistance of the thermal head and calculated voltage drop and power loss. This voltage drop is nearly proportional to the number of active pixels. So we compensated the energy loss of the thermal head with the extra pulse length of strobe pulse.
Heat regeneration is a big problem for thermal printers because of a dull in the tailing edge of high-density printing. Usually it is very difficult to control heat regeneration precisely. We have made the printing data compensated according to the regenerative function, that presents the predictive value of printing density. This regenerative function is calculated from previous values of this function in each pixel. The input data is modified to the printing data according to the compensation value.