| 摘要 |
PROBLEM TO BE SOLVED: To make stably detectable even a small change in the amount of liquid in an ink-detecting apparatus for detecting the amount and the presence or absence of ink. SOLUTION: This liquid detection device is provided with a first integration circuit 12, that includes a capacitor C1 having a predetermined capacity and performs integration operation according to integration time constant corresponding to the capacity of C 1, a second integration circuit 13, that includes a capacitor C2 that is connected to a detection electrode 8 and performs integration operation according to time constant corresponding to the capacity of C2, a drive circuit 11 for performing integration operation on both the integration circuits 12 and 13, and a judgment circuit 14 for judging whether a tip part S8 is immersed into ink or not by comparing integration time, that is shown by signals S2 and S3 by comparing the voltages of output signals S2 and S3 of both the integration circuits 12 and 13. When the tip part S8 is dipped into ink, the capacity of the capacitor S2 increases. The capacity change can be detected by the judgment circuit 14, thus detecting a minute change in the amount of ink. |
