| 摘要 |
PURPOSE:To make it possible to certainly detect an ink residual amount without generating physical change to ink, by a method wherein a conductive liquid is received in a cassette and a pair of electrodes are provided to the upper and lower parts to the side wall of the cassette in separated relation to each other while one side of each electrode is faced to the interior of the conductive liquid while the other side thereof is opposed to the outside of the cassette. CONSTITUTION:In such a state that ink is sufficiently received in an ink bag 1 which is, in turn, set in an ink cassette 4, a conductive liquid 15 is allowed to fill the ink cassette 4 and the non-emission of the ink is not generated. When the ink is consumed and the ink amount in the ink bag 1 begins to decrease and the ink bag 1 becomes flat, a gap 16 is generated to the upper inner side in the ink cassette 4. When the consumption of the ink further advances and the time requiring the exchange of the ink cassette 4 approaches, the interval of the gap 16 becomes extremely large and the conductive liquid 15 is brought to such a state that the level thereof reaches to the upper and lower electrodes 6, 6', an open state is formed between the electrodes 6, 6'. Therefore, no current flows through the ink and an ink residual amount can be certainly detected without changing ink physical properties by using the electrodes. |
