| 摘要 |
PURPOSE:To make it possible to carry out diagnosis in good preciseness by a simple circuit, by a method wherein the diagnostic signal of an intermittent alternating wave form is recorded in place of an image signal and the state of an ink jet head is judged from the shape of the obtained diagnostic recorded pattern. CONSTITUTION:In place of an image signal, the diagnostic signal of an intermittent alternating wave form with amplitude of 0-220V and frequency of 2- 32kHz is inputted and a diagnostic recording pattern is recorded by recording paper 34. In the diagnosis of an ink jet head, an ink emission impossible state can be directly judged because the pattern is not satisfactorily recorded and, because the delay of response is generated in the ink jet head having air bubbles present therein, an emission starting point does not come to a straight line while an emission finishing point does not come to a straight line when a trailing phenomenon is generated. For example, it is understood that the delay of emission response is generated with respect to a signal with frequency of 10kHz and voltage of 60V and 80V in a part (a) while the trailing phenomenon is generated with respect to a signal with frequency of 20kHz and voltage of 180V in a part (b). By this method, the state of the head can be diagnosed in good preciseness. |
