PURPOSE: To realize a heat controlling apparatus for a thermal printer having a line thermal head which prevents the temperature of each dot of the line thermal head from becoming irregular due to the printing state in the lateral direction, and obtains printing of good quality without density irregularity between dots, with no deterioration of service life caused by overheating.
CONSTITUTION: The printing data is output from a memory device 2, and then compared and operated with the printing data in the lateral direction by an operating circuit 3. In the case, for example, where the printing data of three dots continues in the lateral direction synchronously with a clock signal 5, two dots at both ends are pre-heated first, and then all of the three dots are heated for printing. Accordingly, the temperature balance of all the dots of a line thermal head 4 can be maintained.
NARUSE MIKIO
YOSHIHARA SATOSHI
EGUCHI MANABU
HATADA NAOKI
