| 摘要 |
A device for monitoring the supply of printing liquid in the reservoir of an ink-operated printer and the like, in which two monitoring electrodes are disposed in and wetted by the printing liquid, with circuit means being connected to the electrodes for monitoring the electrical resistance therebetween, which resistance varies in response to changes in the amount of ink in the reservoir. Means are provided, responsive to predetermined resistance values, for actuating at least one display element, and/or effecting disconnection of an associated printer. Additional circuit means may also be connected to the monitoring means for actuating a preliminary warning device prior to actual triggering of a display element indicating the exhaustion of the printing liquid supply. Means also may be provided for monitoring the supply of a data carrier, i.e. paper, which means may likewise be operatively connected to the display element, whereby the latter serves as a common display element to indicate both the operational status of the ink supply reservoir and the presence of a data carrier for receiving the printing. |
