| 摘要 |
PURPOSE:To electrically monitor ink residue safely and accurately without direct contact of a detecting element with ink by providing a strain gauge in a flexible bag for storing ink to detect the strain level of the bag corresponding to the filling level of ink. CONSTITUTION:A flexible bag 1 as ink storage container is filled with ink 3 and a strain gauge 2 is provided. As ink 3 in the ink storage container is consumed, a strain is generated in the strain gauge 2. On the other hand, in a detection circuit, a strain gauge 11 and solid resistors 12, 16 and 17 compose a bridge and changes in the resistance proportional to changes in the strain level in the strain gauge 11 are amplified with a differential amplifier 13. When the strain reaches a desired level, it is detected with a voltage comparator 14 and an alarm is given with an indicator 15 or an ink jet recorder is stopped. |
