| 摘要 |
PROBLEM TO BE SOLVED: To provide a coating apparatus capable of surely detecting a bubble. SOLUTION: A capacity sensor 91 is stuck onto an inner wall of a head cylinder 81. The capacity sensor 91 includes a flexible substrate 92 whereon electrode patterns 93 are disposed to form a narrow gap area present therebetween functioning as a capacity measurer C1. A bubble detector judges the condition of bubbles based on the frequency of a pulse signal whose cycle varies according to the time constant determined by the capacity and the resistance of the capacity measurer C1. Since the frequency increases if bubbles are contained in ink in a greater number, the bubble detector determines that the bubbles present therein exceeds an allowable limit when the frequency exceeds a predetermined frequency threshold. COPYRIGHT: (C)2011,JPO&INPIT |
