Liquid container having a liquid consumption detecting device therein

An ink cartridge for an ink jet printer, comprising:

• a housing accommodating therein ink;
• an ink supply opening formed in said housing;
• an ink level detection device comprising a piezoelectric element;
• and
• a storing device mounted on a wall of said housing.

An ink jet printer, comprising:

• a print operation section comprising a print head ejecting ink droplets through nozzles;
• an ink cartridge connecting with said print head for accommodating ink therein, said ink cartridge comprising:
• a housing accommodating therein ink;
• an ink supply opening formed in said housing;
• an ink level detection device comprising a piezoelectric element;
• and
• a storing device mounted on a wall of said housing,
• a control section connecting with said ink level detection device and said storing device of said ink cartridge.

A liquid detecting device, comprising:

• a substrate;
• a sensor mounted on a first portion of said substrate, said sensor comprising a piezoelectric element;
• and
• a memory mounted on a second portion of said substrate.

A liquid detection system, comprising:

• a liquid container comprising:
• a housing accommodating therein liquid;
• a liquid supply opening formed in said housing;
• and
• a liquid level detection device mounted on said housing, said detection device comprising a piezoelectric element,
• a storing device mounted on a wall of said housing of said liquid container;
• and
• a control section connecting with said ink level detection device and said storing device.

A method of detecting a liquid consumption status of liquid contained in a liquid container, comprising steps of:

• reading out information relating to a detection characteristics;
• reading out information relating to a liquid consumption status;
• detecting a new liquid consumption status of liquid contained in the liquid container;
• and
• storing the newly detected liquid consumption status in a memory mounted on the liquid container.