JPS6467358A - Thermal head control method - Google Patents

Abstract

PURPOSE:To enable characters to be printed and recorded without density irregularity by using a simple constitution by performing the scan back and forth over thermosensitive paper after the releasing of heat built up in a thermal head. CONSTITUTION:After a thermal head 9 scans thermosensitive part 6 and printed data shown in a shaded area is recorded, a printing signal supplied to the thermal head 9 is shut off at a point (a). However, the thermal head 9 is caused to scan upto a point (b) together with a base 10 in a condition where the thermal head 9 is kept in contact with the thermosensitive paper 6. The distance from the point (a) to the point (b) is set based on the heat accumulation value of the thermal head 9. Further, it is so arranged that the built-up heat may be released almost completely when the thermal head 9 arrives at the point (b). As a result of the above-mentioned control, the final part (c) of the printing area is to be printed on the same conditions as other printing areas, no overdevelopment of colors by double heating occurs, neither does any density irregularity. After the thermal head 9 scans up to the point (b), it is moved back while it is kept in contact with the thermosensitive paper 6. Thus the thermal head 9 is returned to a printing/recording start position to finish the printing and recording of data of a single line.