| 摘要 |
PURPOSE:To provide the titled detector capable of stably detecting the flying period of a printing hammer and being used even during printing, by a method wherein a counter receives an exciting signal for a printing hammer and an output from a piezoelectric element, and the flying period of the hammer is detected on the basis of the time gap between the exciting signal and the output. CONSTITUTION:The exciting signal 21 is generated by a printing controlling part 2 to operate the hammer 3, and is fed to a flip-flop 15, which feeds an output 22 to the counter 4. When printing is conducted, the piezoelectric element 12 generates a detection signal 23, which is amplified by an amplifier 13, and when the resultant signal is higher than a preset slice level 24, a signal ''1'' is outputted. An OR circuit 14 generates an output 25, and the flip-flop 15 stops feeding the output 22 on receiving the output 25. The counter 4 opens a gate when being inputted with the output 22, counts the number of clock signals 26, converts the count value into time, and causes a display device 16 to display the time as the flying period of the hammer 3. By sequentially repeating these operations for all digit places, for one digit place at a time, the flying periods of all of the hammers can be detected. |
