| 摘要 |
PURPOSE:To detect the residual amount of ink with high accuracy in a small sized in jet printer, by providing a detection means for detecting the consumption of ink on the basis of the gas exhausted from a hermetically closed type ink storage tank in the ink supply route between a recording head and said ink storage tank. CONSTITUTION:The ink residual amount detector 6 communicating with an ink tank 7 is connected to a control part and equipped with a suction means 9 such as a pump for reducing the pressure in the detector 6. When it is detected that the resistance value between a hollow needle 6-2 and an electrode 6-3 is abnormally high because of the consumption of the ink in the tank 7, an information means 1255 issues such an alarm that ink is not almost left to an operator. Corresponding to said alarm, the operator performs replacement work and, when the replacement of the tank 7 is detected by a microswitch, the pump 9 is driven to exhaust the gas in the ink residual amount detector 6 through a pump communication port 6-5 and the interior of said detector 6 is brought to a negative pressure state to introduce the ink in the tank 7 into the detector 6. This negative pressure state is held until the resistance value between the hollow needle 6-2 and the electrode 6-3 becomes low and the pump 9 is stopped. |
