EXPENDABLES CONTAINER CAPABLE OF MEASURING RESIDUAL AMOUNT OF EXPENDABLES

摘要

A device which receives a supply of expendables from an expendables container mounted therein with a piezoelectric element. The device comprises a detection signal generating circuit that charges/discharges a piezoelectric element and generates a detection signal including information showing the frequency of a residual vibration remaining in the piezoelectric element when a specified stand-by time elapses after the completion of a discharge, and a control unit for controlling the charge/discharge of the piezoelectric element. The frequency can be used to determine whether or not the residual amount of stored expendables is larger than a specified amount. The control unit determines a specified stand-by time by counting the pulse count of a clock signal.