Expendable supplies container capable of determining residual quantity of expendable supplies
The invention relates to a variable capacitance sensor for measuring a quantity of consumable supplies present in a container or a reservoir.
The sensor can be used in an ink cartridge, a carbon powder cartridge, a water reservoir, a oil reservoir, or a reagent reservoir.
The voltage value applied onto the variable capacitance sensor changes the capacitance of the sensor. The pressurizing force applied onto the variable capacitance sensor changes the capacitance of the sensor. The variable capacitance sensor and the residual expendables work as a resonant system. The capacitance about the variable capacitance sensor varies with a variation in residual quantity of expendables. The frequency of the resonant system varies with a variation in residual quantity of the expendables, since the variation in residual quantity of the expendables causes a variation of the capacitance of variable capacitance sensor.
A controller computes the resonant frequency of the voltage wave from the count and estimates a remaining state of the expendables according to the computed frequency.
Presetting a voltage applied onto the variable capacitance sensor is capable of varying the preset frequency of the resonant system.
CN 2,008,101,897,803 issued 2011-04-06
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Sale or Licensing
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