| 摘要 |
PURPOSE:To prevent the failure of a printing hammer and the deterioration of printing quality, by a method wherein a temperature detecting means detecting the temperature of a hammer bank is provided in the hammer bank and the exciting cycle of the printing hammer is so controlled as to be extended with increasing temperature. CONSTITUTION:In a printer, the temperature of an exciting coil mounted on a printing hammer is increased when a character pattern with a high printing duty is continuously printed. This temperature increase is detected as a change of voltage by a temperature-voltage conversion device 48 mounted on a hammer bank 10. The voltage of the temperature-voltage conversion device 48 is inputted to a reference pulse generation circuit 2 and digitized to form a long-cycle reference pulse signal according to the temperature increase of the hammer bank 10. On the basis of the long-cycle reference pulse signal, the uniform speed control of the hammer bank 10 is conducted to extend the printing cycle of the printing hammer. In this manner, as a result of the reduction of a conduction duty to the coil, the temperature increase of the printing hammer can be inhibited and the reduction of printing quality caused by the characteristics of the hammer deteriorating with increasing temperature can be prevented. |
