| 摘要 |
PURPOSE:To detect a residual quantity of ink in an ink tank, by providing a pressure detecting means between the ink tank and a means of supplying ink with pressure, and by detecting the pressure of ink thereby in linkage to the supply of ink with pressure. CONSTITUTION:A detecting operation is performed in linkage to the ON/OFF operation of a driving switch 11 of a device 8 for supplying ink with pressure, by a pressure detector 4 which is provided in the middle part of an ink supply channel 5A. Under the condition that sufficient ink is in an ink tank 1, the negative pressure inside the ink supply channel 5A is stable at an approximately fixed level between a prescribed empty level and the atmospheric pressure, although only small pulsations generated by the roller 19 of a rotor 18 of the device for supplying ink with pressure are perceived. When the residual quantity of ink in the ink tank 1 decreases, the negative pressure falls below the empty level. Therefore, when an alarming unit 13 is devised to be driven on the occasion, for instance, the state that the residual quantity of ink in the ink tank is small can be informed of. |
