| 摘要 |
PURPOSE:To stop ejection of ink droplets at the time of an abnormal condition- detecting operation, by providing a plurality of electro-mechanical converting elements for each nozzle, applying an abnormal condition-retrieving signal to a part of the elements, and using at least one of the remainder of the elements as an abnormal condition detector. CONSTITUTION:In the case of recording on a recording material by causing ink droplets 10a, 10b to fly from nozzles 1a, 1b, a series of driving pulse signals are applied to a plurality of electro-mechanical converting elements 8a, 8b, 9a, 9b, and the ink droplets 10a, 10b are ejected by interactions between the elements and the signals. At the time of detecting an abnormal condition in a nozzle head 1, switches SW1, SW2 are changed over to B1 and B2 sides, respectively, thereby connecting the elements 9a, 9b to a sensor device 13. Driving pulse signals suitable for the purpose of detecting the abnormal condition are applied to the elements 8a, 8b, and pressure vibrations in ink chambers 5a, 5a' and 5b, 5b' are picked up as two electrical signals by the elements 9a, 9b, thereby detecting the pressure vibrations and hence the abnormal condition. |
