| 摘要 |
PURPOSE:To make printing density uniform, in the thermal head wherein a divided driving method of direct driving type is used, by detecting the temperatures of the divided blocks in the thermal head by temperature sensing elements, and controlling the widths of the conducting pulses to the blocks. CONSTITUTION:In the thermal head, wherein the divided driving method of direct driving type is used, the signal blocks which are divided in he divided driving are equal to the space blocks which are divided in the head. For example, the blocks divided into 4 parts also constitute the space blocks 1-4. The temperatures of blocks are detected by thermistors TH1-TH4, respectively. The width of the pulse of each strobe signals is controlled in correspondence with the detected result. The current conducting times for the heaters in the blocks 1-4 are appropriately varied, and the printing density in the main scanning direction can be made uniform. |
