METHOD FOR INCREASING THERMAL PRINT QUALITY

A printing method for printing a pixel at a gray level x on paper by a printer. The printer includes a thermal print head, which includes a heater for heating a ribbon to print pixels from gray levels 1 to m−1 on the paper, and the ribbon. The method includes: if x is not greater than a value n, heating the ribbon x times and evenly distributing the heating initiation times of the x times between the time point 0 and the time point (m*(x−1)/n) for printing the pixel at gray level x on the paper. If x is greater than the value n, heating the ribbon x times and evenly distributing the heating initiation time of the n times between the time point 0 and the time point (m*(n−1)/n) and distributing the heating initiation times of the x−n times after the heating initiation time points of the n times.