Patent ID: 7280928
Filing Date: 2007-10-09
Classification: B41J,G01F

Abstract:
1. An expendable container capable of measuring a residual quantity of stored expendable, the expendable container comprising: an expendable tank configured to store the expendable and has a piezoelectric element attached thereto; a detection signal generation circuit configured to charge and discharge the piezoelectric element, and generate a detection signal including cycle information, the cycle information representing a cycle of an output voltage wave of the piezoelectric element after the discharge; and a control module configured to control the charge and the discharge of the piezoelectric element by the detection signal generation circuit, wherein the detection signal generation circuit comprises: a comparator configured to compare a voltage of the output voltage wave with a reference voltage for residual quantity detection, and generate a pulse according to a result of the comparison; and a signal generator configured to generate the detection signal in response to the generated pulse, wherein the control module is capable of varying the reference voltage for residual quantity detection, the expendable container further comprising: a non-volatile memory configured to store setting information on the reference voltage for residual quantity detection, the setting information on the reference voltage for residual quantity detection representing a relation between the reference voltage for residual quantity detection and piezoelectric element characteristic information indicative of a characteristic of the piezoelectric element, wherein the control module is capable of setting the reference voltage for residual quantity detection according to a given piece of the piezoelectric element characteristic information and the setting information on the reference voltage for residual quantity detection.