Ink-jet printer having an ink jet print head end of life detection circuit

An ink-jet printer, comprising:

• an ink-jet head having a ink tank for holding therein a conductive ink, a nozzle associated with said ink tank, and a pair of electrodes disposed on a portion of an inside wall of said ink tank;
• electrode excitation means for applying a voltage to said pair of electrodes such that a current is passed through that portion of said conductive ink contained between said pair of electrodes to cause said portion of the conductive ink to become vaporized to produce bubbles and cause said bubbles to expand suddenly, exerting a sufficient pressure onto said conductive ink to expel droplets of conductive ink from said nozzle;
• current detection means for detecting a current value flowing through said portion of the conductive ink contained between said pair of electrodes;
• lifetime detection means for producing an output signal indicative of the end of a lifetime of said pair of electrodes based on an output from said current detection means;
• and
• alarm means for displaying the lifetime end of said pair of electrodes in response to said output signal received from said lifetime detection means.

An ink-jet printer, comprising:

• an ink-jet head having an ink tank for holding therein a conductive ink, a nozzle associated with said ink tank, and a pair of electrodes disposed on a portion of an inside wall of said ink tank;
• electrode excitation means for applying a voltage to said pair of electrodes such that a current is passed through that portion of said conductive ink contained between said pair of electrodes to cause said portion of the conductive ink to become vaporized to produce bubbles and cause said bubbles to expand suddenly, exerting a sufficient pressure onto said conductive ink to expel droplets of conductive ink from said nozzle;
• current detection means for detecting a current value flowing through said portion of the conductive ink contained between said pair of electrodes;
• lifetime detection means for producing an output signal indicative of the end of a lifetime of said pair of electrodes base don an output from said current detection means;
• and
• stop means for stopping application of said voltage from said electrode excitation means to said pair of electrodes, in response to said output signal received from said lifetime detection means.

An ink-jet printer comprising:

• an ink-jet head having an ink tank for holding therein a conductive ink, a nozzle associated with said ink tank, and a pair of electrodes disposed on a portion of an inside wall of said ink tank;
• electrode excitation means for applying a voltage to said pair of electrodes such that a current is passed through that portion of said conductive ink contained between said pair of electrodes to cause a part of said portion of the conductive ink to become vaporized to produce bubbles and cause said bubbles to expand suddenly, exerting a sufficient pressure onto said conductive ink to expel droplets of conductive ink form said nozzle;
• current detection means for detecting a current value flowing through said portion of the conductive ink contained between said pair of electrodes;
• lifetime detection means for producing an output signal indicative of the end of a lifetime of said pair of electrodes based on an output from said current detection means;
• alarm means for displaying the lifetime end of said pair of electrodes in response to said output signal received from said lifetime detection means;
• and
• stop means for stopping application of said voltage from said electrode excitation means to said pair of electrodes in response to said output signal received from said lifetime detection means.

An ink-jet printer, comprising:

• an ink-jet head having an ink tank for holding therein a conductive ink, a nozzle associated with said ink tank, and a pair of electrodes disposed on a portion of an inside wall of said ink tank;
• electrode excitation means for applying a voltage to said pair of electrodes such that a current is passed through that portion of said conductive ink contained between said pair of electrodes to cause said portion of the conductive ink to become vaporized to produce bubbles and cause said bubbles to expand suddenly, exerting a sufficient pressure onto said conductive ink to expel droplets of conductive ink from said nozzle;
• current detection means for detecting a current value flowing through said portion of the conductive ink contained between said pair of electrodes when said portion of the conductive ink is vaporized;
• and
• lifetime detection means for producing an output signal indicative of the end of a lifetime of said pair of electrodes based on an output from said current detection means.