Ink-jet recording apparatus

An ink-jet apparatus comprising:

• an ink-jet head which includes a plurality of nozzle openings, a plurality of independent ejection chambers each having side walls and respectively correspondingly communicated with said nozzle openings, diaphragms respectively correspondingly formed in said ejection chambers partly on at least one of said walls of each of said ejection chambers, a plurality of driving means for respectively correspondingly driving said diaphragms, and a common ink cavity for supplying ink to said plurality of ejection chambers so that, upon application of electric pulses to said plurality of driving means, said driving means respectively distort said diaphragms from a normal position by electrostatic force via said applied pulses to a distorted position and then respectively release said diaphragms upon either withdraw of said applied pulses or after reverse of polarity of said applied pulses permitting said diaphragms to distort in a direction inwardly of said chambers thereby increasing respective pressures in said ejection chambers to eject ink drops from said nozzle openings onto a recording paper,
• wherein said respective driving means are constituted by electrodes disposed respectively adjacent to said diaphragms with respective vibration chambers formed between said diaphragms and said electrodes for respectively correspondingly distorting said diaphragms by electrostatic force, said electrodes protected from electrical shorting with portions of said ink-jet head, and said vibration chambers in communication with the air through air passages.

An ink-jet apparatus comprising:

• an ink-jet head which includes a plurality of nozzle openings, a plurality of independent ejection chambers each having side walls and respectively correspondingly communicated with said nozzle openings, diaphragms respectively correspondingly formed in said ejection chambers partly on at least one of said walls of each of said ejection chambers, a plurality of driving means for respectively correspondingly driving said diaphragms, a plurality of orifice inlets for respectively supplying ink to each of said ejection chambers, and a common ink cavity for supplying ink to said plurality of ejection chambers through said orifice inlets so that, upon application of electric pulses to said plurality of driving means, said driving means respectively distort said diaphragms from a normal position by electrostatic force via said applied pulses to a distorted position and then respectively release said diaphragms upon either withdraw of said applied pulses or after reverse of polarity of said applied pulses permitting said diaphragms to distort in a direction inwardly of said chambers thereby increasing respective pressures in said ejection chambers to eject ink drops from said nozzle openings onto a recording paper,
• said respective driving means comprising electrodes disposed respectively adjacent to said diaphragms for respectively distorting said diaphragms by electrostatic force, and
• wherein a cross sectional circumference of a respective one of said plurality of orifice inlets is smaller than a cross sectional circumference of a respective one of said nozzle openings.

An ink-jet apparatus comprising:

• an ink-jet head which includes a plurality of nozzle openings, a plurality of independent ejection chambers each having side walls and respectively correspondingly communicated with said nozzle openings, diaphragms respectively correspondingly formed in said ejection chambers partly on at least one of said walls of each of said ejection chambers, a plurality of driving means for respectively correspondingly driving said diaphragms, and a common ink cavity for supplying ink to said plurality of ejection chambers so that, upon application of electric pulses to said plurality of driving means, said driving means respectively distort said diaphragms from a normal position by electrostatic force via said applied pulses to a distorted position and then respectively release said diaphragms upon either withdraw of said applied pulses or after reverse of polarity of said applied pulses permitting said diaphragms to distort in a direction inwardly of said chambers thereby increasing respective pressures in said ejection chambers to eject ink drops from said nozzle openings onto a recording paper,
• wherein said respective driving means are constituted by electrodes disposed respectively adjacent to said diaphragms for respectively distorting said diaphragms by electrostatic force, said electrodes protected from electrical shorting with portions of said ink-jet head,
• said ink-jet head being a lamination structure including an intermediate substrate disposed between a first and a second substrate, said ejection chambers comprising cavities formed within said intermediate substrate and having first wall portions facing towards said first substrate, said first wall portions comprising said diaphragms of said chambers, and said electrodes being disposed on said first substrate and opposite to corresponding ones of said diaphragms.

An ink-jet recording apparatus comprising an ink-jet head having a plurality of nozzle openings, a plurality of independent ejection chambers respectively communicating to each of said nozzle openings from which ink drops are ejected due to the deformation of diaphragms, each of said chambers having walls, each of said diaphragms forming one of the side walls of each of said ejection chambers,

• wherein the ink-jet head consists of:
• a silicon substrate comprising at least
• a plurality of first channels each constituting a part of each of said ejection chambers,
• a second channel constituting a part of an ink cavity for storing ink, and
• a plurality of third channels, which are shallower than said first and second channels, each constituting a part of ink supplying paths which supply ink to each of said ejection chambers from said ink cavity;
• a cover substrate connected to said silicon substrate and forming said ejection chambers, said ink cavity and said ink supplying paths together with said first, second and third channels respectively;
• and
• an insulating substrate connected to said silicon substrate and provided with electrodes respectively in facing relation to the one side walls comprising said diaphragms, each of said first channels approximately in parallel relation with the one side wall diaphragm, and a gap formed between each of said diaphragms and said electrodes;
• and driving means for distorting said diaphragms of said first channels by electrostatic force obtained by applying pulse voltage to said electrodes.

An ink-jet head for an ink-jet recording apparatus, comprising:

• a silicon substrate comprising in one surface first channels, a second channel and third channels that are shallower in a depth direction into the silicon substrate from the one surface than the first and second channels, the third channels respectively connecting the first channels to the second channel, and the first channels having diaphragm means on a respective wall of the first channels in the depth direction, said diaphragm means distorted from a normal position by respective electrostatic charges and return to the normal position upon release;
• a cover substrate on the one surface of the silicon substrate for forming the second channel into a cavity for storing ink, forming the third channels into respective inlets for the ink from the ink-storing cavity into the first channels and forming the first channels into respective ejection chambers for the ink;
• an insulating substrate at an opposite surface of the silicon substrate to the one surface thereof having electrodes respectively spaced from and aligned with said diaphragm means;
• driving means for respectively applying the electrostatic charges to the electrodes from controlled pulse voltages, whereby the respective diaphragm means are distorted from the normal position and then released to the normal position;
• and
• nozzle means respectively extending from the ejection chambers, each for ejecting an ink drop when the diaphragm means of a respective ejection chamber is released.