| 摘要 |
PURPOSE:To keep recording density constant, by detecting applied voltage for allowing a thermal head to generate heat plural times and calculating the value based on the detected value to control a heat generating time. CONSTITUTION:When a printing order PO is generated when a carriage 3 was present at a home position, an AND gate a1 is opened and the output of a 4-phase duplex driver D is applied to a pulse motor 11. After a predetermined time, an AND gate a2 is also opened to detect the voltage of a power source. This detection is performed several times at a predetermined time interval and the average value of the detected values is calculated in an A/D converter. On the basis of the digital value at this time, a table TB is addressed and the heat generating time of a thermal head and a motor driving time are set to perform printing. By detecting applied voltage for allowing the thermal head to generate heat plural times, the heat generating time of the thermal head is controlled and, therefore, recording density can be kept constant with good accuracy. |
