| 摘要 |
PURPOSE:To detect the residual amount of an ink accurately by a method wherein a flat plate having an electrical contact is pressed against an ink bag so that the electrical contact is contacted to another electrical contact fixed to an ink storing vessel when the residual amount of ink is reduced to or below a predetermined amount. CONSTITUTION:When the ink in an ink storing bag 2 is consumed and the residual amount of the ink is decreased with the progress of printing in an ink jet printer, the bag 2 is gradually contracted by the negative pressure inside the bag 2 and spring forces of leaf springs 5, 5', so that the flat plate 6 held between the bag 2 and the springs 5, 5' is lowered toward a lower case 1b. When the residual amount of ink is reduced to or below a predetermined level, the contacts S1-S4 are contacted to the contacts C1-C4 respectively, and when all the four pairs of the contacts are contacted, an alarm is issued. |
