Electrostatic ink jet recording apparatus ejecting ink using different electric potentials applied to different electrodes

An electrostatic ink jet recording apparatus comprising:

• a head body having an ink chamber in which ink charged to a specified polarity is stored, and having a plurality of ink ejection ports that are coupled to said ink chamber;
• a plurality of ejection electrodes respectively provided for said plurality of ink ejection ports, each of said ejection electrodes being positioned at one end of said corresponding ink ejection port that is furthest away from said ink chamber, said ejection electrodes including at least a first subset of said ejection electrodes, a second subset of said ejection electrodes, and a third subset of said ejection electrodes, wherein said first subset, said second subset and said third subset are interleavedly disposed with respect to each other;
• an opposite electrode device disposed a predetermined distance away from said head body;
• a plurality of opposite electrodes opposed to said plurality of ejection electrodes, said plurality of opposite electrodes being disposed on said opposite electrode device, said plurality of opposite electrodes including a first subset of said opposite electrodes which are opposedly positioned with respect to said first subset of said ejection electrodes, a second subset of said opposite electrodes which are opposedly positioned with respect to said second subset of said ejection electrodes, and a third subset of said opposite electrodes which are opposedly positioned with respect to said third subset of said ejection electrodes;
• an ejection voltage drive unit receiving a recording signal and driving said plurality of ejection electrodes on a time division basis so that when one of said first subset, said second subset and said third subset of said ejection electrodes is driven, the other subsets of said ejection electrodes are not driven;
• and
• an opposite potential setting unit receiving a drive information signal from said ejection voltage drive unit, and driving said plurality of opposite electrodes on the time division basis so that when one of said first subset, said second subset and said third subset of said opposite electrodes is driven with a second voltage, the other subsets of said opposite electrodes are driven by a third voltage closer in value to a first voltage than said second voltage is.

A method of injecting ink onto a recording paper disposed between a head body which includes a plurality of ejection electrodes, which includes subsets of ejection electrodes, and an opposite electrode device which includes a plurality of opposite electrodes, which includes subsets of opposite electrodes, that are positioned on a one-to-one basis with respect to said plurality of ejection electrodes, the method comprising the steps of:

• a) providing a first signal to drive a subset of said subsets of said plurality of ejection electrodes by a first voltage, while not driving any others of said ejection electrodes, each of said ejection electrodes in said first subset not be directly adjacent to any others of said ejection electrodes in said subset;
• b) providing a second signal to drive a subset of said subsets of said opposite electrodes, which are opposedly positioned with respect to said subset of said ejection electrodes, at a same time that said subset of said ejection electrodes are driven, the subset of said opposite electrodes being driven by a second voltage that is different enough in voltage from said first voltage so as to create an electrical attraction of ink ejected from said subset of said ejection electrodes towards a corresponding one of said subset of said opposite electrodes;
• and
• c) at the same time the second signal is provided to drive said subset of said opposite electrodes, driving another subset of said opposite electrodes by a third voltage that is closer in voltage to said first voltage than said second voltage is.