| 摘要 |
PROBLEM TO BE SOLVED: To surely detect ejection of a liquid droplet without being affected by adhering of a liquid droplet to a sensor or the environment and to detect an ejection condition including an ejection direction of a liquid droplet. SOLUTION: A plurality of hall sensors 26 are provided on a coaxial circle around a center of an ink droplet on a face perpendicular to a movement direction of an ink droplet ejected from a head 10. An ink polarity adjustment mechanism 16 is provided to a portion between the head 10 and the face having the hall sensors 26 provided thereon or in the head 10 and polarities of magnetic materials included in an ink droplet ejected from the head 10 are aligned by means of the ink polarity adjustment mechanism 16. The pass-through of a liquid droplet ejected from the head 10 is detected by the plurality of hall sensors 26. Based on the detected result of the hall sensors 26, the ejection of the liquid droplet is detected as well as the ejection direction and the size of the liquid droplet are detected. COPYRIGHT: (C)2006,JPO&NCIPI |
