THERMAL PRINTER

摘要

PROBLEM TO BE SOLVED: To suppress unevenness of density, which is caused by a change in resistance of a heater element due to use. SOLUTION: The resistance Riof the heater element 31iis measured by a resistance measuring part 45 at each time when the number of integrated prints, counted by a counter 48, exceeds five hundreds. A differenceΔR1iis calculated by subtracting the resistance Rifrom a mean resistance Rm, and a correction factor k1iis obtained by referring to a conversion table of a resistance correction factor part 47. A differenceΔR2ibetween the resistances Ri+1and Riof the adjacent heater elements is calculated, and a correction factor k2iis obtained by referring to another conversion table of the factor part 47. The correction factor k1iis multiplied by the correction factor k2iso that a correction factor kiof each heater element can be calculated and stored in a flash memory 46. In printing, the correction factor kiis read out from the flash memory 46 so that image data in a frame memory 34 can be corrected. COPYRIGHT: (C)2004,JPO