| 摘要 |
PROBLEM TO BE SOLVED: To detect presence or flow rate of passing liquid with high accuracy without touching the passing liquid or liquid drop by detecting radiation wave emitted from the liquid or liquid drop and detecting variation in the detected value. SOLUTION: A recording head 5 comprises a large number of nozzles 201 being filled with ink and ejecting the ink, and a large number of heaters 202 being heated at a specified timing. When each heater 202 is fed with power and ink in each nozzle 201 is heated, an ink bubble is generated and an ink liquid drop 101 is ejected. In the vicinity of passage of the ink liquid drop 101, a radiation wave detecting section 203 is located at a position not touching the ink liquid drop 101. More specifically, radiation wave of infrared wavelength band emitted from the heated ink liquid drop 101 is detected at a radiation wave detecting section 203 comprising an infrared sensor and variation in the detected output is detected by a detection circuit 204 thus detecting passage or flow rate of ink liquid drop 101 with high accuracy. |
