| 摘要 |
An ink cartridge (10) of the invention has a sensor (17) to detect the presence or the absence of ink. A control device (22) of a printer (20) transmits a detection command and a specified detection condition to the ink cartridge (10) by radio communication. In response to input of the detection command into the ink cartridge (10), a sensor controller (19) actuates and vibrates the sensor (17) under the specified detection condition. The sensor (17) is attached to a resonance chamber (18), which is disposed in an ink chamber (16). The frequency of the vibration of the sensor (17) is thus regulated by a resonance frequency of the resonance chamber (18). The resonance frequency is varied by the presence or the absence of ink in the resonance chamber (18). Detection of the resonance frequency accordingly specifies the presence or the absence of ink in the resonance chamber (18) and thereby the remaining quantity of ink in the ink cartridge (10). The control device (22) of the printer (20) receives the result of the detection together with the detection condition from the ink cartridge (10), and checks whether or not the detection has been carried out under the specified detection condition, in order to verify the validity of the detection result. This technique of the invention is generally applicable to a cartridge that holds a recording material used for printing therein, for example, an ink or a toner, and detects the state of the recording material. The arrangement flexibly handles the change in detection condition and ensures the sufficiently high reliability of the detection. <IMAGE> |
