| 摘要 |
PURPOSE:To make possible the control of a platen to maintain the same gap and thereby ensure certain printing quality constantly by controlling a drive device so that the platen is moved in a desired direction until the gap remains unchanged based on an output from a device to detect a gap between a printing head and a platen. CONSTITUTION:A reflection-type sensor 14 consists of a transmission section which transmits an optical wave or a sound wave as a transmission signal to a platen 12 and a reception section which receives a signal reflected by the platen 12. The transmission and reception are controlled by a control signal 100 to be output from a control circuit 18. A reflected signal from the platen 12 is captured by the reception section inside the sensor 14 and then is output to the circuit 18 in response to a signal 100 to be output again from the circuit 18. The circuit 18 calculates a distance between a printing head 10 and the platen 12 based on an incoming and a reflected signal from the sensor 16 and outputs a drive signal 102 which drives a motor 16 until a specified platen gap is obtained, to the motor 16. |
