Line thermal printer having power supply capacity matched to number of

Abstract

A line thermal printer has a line thermal head comprised of a plurality of physical blocks arranged in a line. Each physical block has a plurality of heat generation elements to which power is selectively supplied for dot printing a line. A driving circuit has driving blocks corresponding to the physical blocks and selectively supplies power to the heat generation elements line-by-line in line sequence in accordance with the printing dot data. Printing dot data memory blocks are connected to corresponding ones of the driving blocks and supply the printing dot data to the driving circuit in synchronism in line sequence timing. A printing dot counter has counter blocks connected to corresponding ones of the printing dot data memory blocks and counts the printing dot number on the basis of the printing dot data held in the memory blocks for each line of print. A control circuit is connected between the printing dot counter and the driving circuit and forms logic blocks by combining a plurality of physical blocks on the basis of the printing dot number counted by each counter block within a range which does not exceed a predetermined maximum allowable number of heat generation elements which can be supplied with power.