Ink jet recording apparatus with abnormal state detection

An ink jet recording apparatus for recording information by ejecting ink droplets onto a recording medium, said apparatus comprising:

• a recording head having a plurality of ejection outlets for ejecting ink droplets, a plurality of ink liquid passages, each ink liquid passage corresponding to a respective one of said plurality of ejection outlets, each ink liquid having a normal or an abnormal state, and a plurality of electro-thermal converting elements for generating thermal energy for ejecting the ink droplets, each of said plurality of electro-thermal converting elements having a resistance valve and being located in a respective one of said plurality of ink liquid passages, and said plurality of electro-thermal converting elements being used in such a manner as to be divided into a predetermined number of blocks when a state of said plurality of electro-converting elements are measured;
• driving means for driving said electro-thermal converting elements of said recording head to generate thermal energy enough to eject the ink droplets;
• measuring means for, on a basis of individual blocks of the predetermined number of blocks, measuring respective signals in accordance with resistance values of said plurality of electro-thermal converting elements of one block;
• and
• judging means for judging presence of an abnormal state in each of said plurality of ink liquid passages of the one block according to the signals measured by said measuring means.

An ink jet recording apparatus for recording information by ejecting ink droplets onto a recording medium, said apparatus comprising:

• a recording head having a plurality of ejection outlets for ejecting ink droplets, a plurality of ink liquid passages, each ink liquid passage having a normal or abnormal state and corresponding to a respective one of said plurality of ejection outlets, and a plurality of electro-thermal converting elements for generating thermal energy for ejecting the ink droplets, each os said plurality of electro-thermal converting elements having a resistance value and being located in a respective one of said plurality of ink liquid passages, and said plurality of electro-thermal converting elements being used in such a manner as to be divided into a predetermined number of blocks when a state of said plurality of electro-converting elements are measured;
• driving means for driving said electro-thermal converting elements of said recording head to generate the thermal energy enough to eject the ink droplets;
• measuring means for, on a basis of individual blocks of the predetermined number of blocks, measuring respective signals in accordance with resistance values of said plurality of electro-thermal converting elements of one block;
• judging means for judging a presence of an abnormal state in each of said plurality of ink liquid passages of the one block according to the signals measured by said measuring means;
• and
• ejection recovery means for discharging ink from said plurality of ink liquid passages when said judging means judges a presence of the abnormal state.

An ink jet recording apparatus for recording information by ejecting ink droplets onto a recording medium, said apparatus comprising:

• a recording head having a plurality of ejection outlets for ejecting ink droplets, a plurality of ink liquid passages, each ink liquid passage having a normal or abnormal state and corresponding to a respective one of said plurality of ejection outlets, and a plurality of electro-thermal converting elements, each of which is located in a respective one of said plurality of ink liquid passages, for generating thermal energy for ejecting the ink droplets;
• driving means for driving said plurality of electro-thermal converting elements of said recording head to generate the thermal energy;
• sound-wave detecting means for detecting a sound wave occurring in each of said ink liquid passages while the ink droplets are caused to be ejected by said driving means, said sound-wave detecting means being disposed in a neighborhood of said recording head;
• and
• judging means for judging a presence of an abnormal state in each of said plurality of ink liquid passages according to the sound-wave detected by said sound-wave detecting means .