| 摘要 |
The nozzle failure determination result of discharge failure detection does not consider the heater state of a nozzle, so even a nozzle failure caused by nozzle clogging or the like is determined as a failure. The heater state of an abnormal nozzle can be determined only after driving once, causing a nozzle to be damaged unwantedly. This invention has been made to solve this problem. Whether a nozzle failure has occurred is determined based on the results of both a discharge failure detection operation and heater resistance measurement operation. Detection can be achieved quickly by performing heater resistance measurement during the quiescent period in the discharge failure detection operation. When the discharge failure detection operation is executed after heater resistance measurement, driving of an abnormal nozzle and an unwanted damage to a nozzle can be prevented. |
