| 摘要 |
PURPOSE:To allow the generated torque of a carriage motor to change and thereby make possible the efficient drive of the motor by controlling the supply of electric current to the carriage motor depending upon the temperature condition of a printer. CONSTITUTION:A constant current circuit control section 7 determines the reference amount of electric current from the operating condition of a carriage motor which is obtained from CPU 9 and the temperature condition of a printer which is obtained from a temperature detection circuit 8. Then said control section controls an electric current supply to the carriage motor 4 through a constant current circuit 6 so that the amount of electric current applied to the carriage motor 4 does not exceed the reference amount of electric current. In this case, if the temperature of the printer is higher than a temperature detected by the temperature detection circuit 8, an output 10 from the temperature detection circuit 8 at 'H' level. Consequently, no change occurs in the reference amount of electric current and the amount of electric current supplied to the carriage motor 4 is normal. In the meantime, if the temperature of the printer is lower than the detected temperature, the output 10 from the temperature detection circuit 8 is at 'L' level. Therefore, the reference amount of electric current is low due to a normal temperature condition. Subsequently, it is possible to prevent damage caused to the carriage motor 4 due to heating at the time of normal or high temperatures. Thus the efficient drive of the motor is ensured. |
