| 摘要 |
PURPOSE:To obtain a drive circuit for low-cost thermal printers capable of being driven by cells by a method in which time of reaching charging levels is converted into pulse width, and the time of electrifying to heating elements is determined by the output. CONSTITUTION:When charging to a condenser 7 is started, charging time till reference voltage E is sent out as a pulse waveform with pulse width (t) to the output terminal of a comparison circuit 11. The pulse width (t) determins electrifying time of heating elements, and a characteristic curve 31 is for the case of reference voltage E=0.7V by a pulse generating circuit 18. The range approximated to the straight line becomes from J-point to K-point, and the range of x=5.7-9.2 at x-axile results. From the viewpoint of voltage values, the range becomes the range of 4.6V-6.4V since xXE=vc, showing the expansion of isoenergy characteristics to great extent. In short, even when the voltage of a power source 1, e.g., cells, etc., is lowered, proper recording density can be secured. |
