| 摘要 |
PROBLEM TO BE SOLVED: To perform printing work smoothly by grasping the residual quantity of ink in an ink tank and the timing for replacing an ink cartridge accurately during printing work. SOLUTION: The residual liquid quantity detector in a liquid jet unit comprises a liquid tank 14 for storing liquid being supplied to a liquid jet head 11, a liquid cartridge 17 to be coupled removably with the liquid tank 14, and a pump 19 for supplying ink from the liquid cartridge 17 to the liquid tank 14. The residual liquid quantity detector further comprises a liquid level sensor 27 for making a decision that the quantity of liquid in the liquid tank 14 is lower than a specified value by detecting noncontact state of the liquid level of liquid in the liquid tank 14, and means for separating the liquid level of liquid in the liquid tank 14 by a specified interval from the liquid level sensor 27 when a decision is made the quantity of liquid in the liquid tank 14 is lower than a specified value. |
