| 摘要 |
PROBLEM TO BE SOLVED: To provide a bubble size determining device which can detect the size of a bubble present in a fluid flowing through a channel, and to provide a maintenance device, and a fluid ejection device. SOLUTION: The bubble size determining device includes: an acute head portion 19a of a feeding needle 19, which is arranged at a vertical intermediate point of the feeding needle 19, for inhibiting a bubble B in ink from moving upward; a light emitting device 26 and a light receiving section 27 which are arranged at a vertical intermediate point of the feeding needle 19 and at predetermined locations on a downstream side of the needle head portion 19a, for detecting presence/absence of the bubble B; and a control device for determining whether or not the size of the bubble B is not smaller than a bubble critical size, based on the intensity of electric current input from the light receiving section 27. COPYRIGHT: (C)2008,JPO&INPIT |
