Non-linear power control of thermal printheads in plastic card printers

A multicolor image is printed on a non-vinyl plastic identity document in an identity document printing system. Pixel density data of a multi-color image to be printed is adjusted using a non-linear pixel density adjustment curve, thereby adjusting the power applied to the thermal printhead. Adjusting pixel density data using a non-linear pixel density adjustment curve improves the quality of the resulting multicolor printed image, reduces mass transfer of the dye donor layer, and reduces cracking of the print ribbon carrier film. 在身份证件打印系统中在非乙烯基塑料身份证件上打印多色图像。使用非线性像素密度调节曲线调节要打印的多色图像的像素密度数据，从而调节施加到热打印头的功率。使用非线性像素密度调节曲线调节像素密度数据提高了所得到的多色打印图像的质量，减少了染料供体层的巨量转移，并且减少了打印色带载体膜的破裂。