APPARATUS AND METHOD FOR DETERMINING AMOUNT OF CONSUMED MATERIAL, PRINTER APPARATUS, BUSINESS EQUIPMENT, COMPUTER READABLE MEMORY, AND DETECTING APPARATUS

摘要

PROBLEM TO BE SOLVED: To accurately detect the amount of a consumption material in a tank by constituting a capacitor so that part of the tank is set in a dielectric space defined by two conductive plates and detecting a signal changing in accordance with a capacitance of the capacitor. SOLUTION: A first metallic plate 56 forming a capacitor 36 is fixed outside an ink (consumable) tank 24 on a carriage, and another plate is constituted of a circuit of a silicon substrate forming a part of a recording head 20. The tank 24 is practically set in a dielectric space of the capacitor 36, and therefore the amount of ink in the tank 24 can be detected from a dielectric constant of the dielectric space, namely, a capacitance of the capacitor 36. In determining the amount of ink in the tank 24, when the carriage carrying the tank 24 is present at a predetermined idling position, a selector 34 is controlled by a main processing circuit 40 to isolate the capacitor 36 from an amplifier 18 and connect to a gyrator 74. The amount of ink is estimated from a resonance frequency of a resonant circuit 62.