Inkjet recording apparatus

An inkjet printer provided with an inkjet print head comprising:

• a nozzle;
• an ink path in communication with said nozzle;
• an actuator comprising
• a diaphragm provided at one part of said ink path;
• and
• an electrode provided in opposition to said diaphragm and separated by a predetermined distance therewith;
• a vibration chamber having first and second walls, said first wall comprising of portion of said diaphragm and second wall being disposed on said electrode;
• drive means for selectively charging and discharging said actuator to thereby eject ink droplets from said nozzle for recording, wherein when said drive means charges said actuator, said diaphragm is displaced to a first position, and wherein when said drive means discharges said actuator said diaphragm is displaced to a second position to eject ink droplets from said nozzle,
• wherein said vibration chamber is sealed and airtight,
• wherein said vibration chamber has a first volume V.sub.1 when said diaphragm is in the second position and a second volume V.sub.2 when said diaphragm is in the first position,
• wherein .DELTA.V is defined as the first volume V.sub.1 less the second volume V.sub.2, and
• wherein 2.ltoreq.V.sub.1 /.DELTA.V.ltoreq.8.

A method for recording on a sheet of paper comprising the steps of:

• providing a marking fluid jet head formed in a semiconductor substrate having a nozzle, a pathway in communication with the nozzle, an actuator comprising a diaphragm provided at one part of the pathway, a first electrode provided in opposition to the diaphragm and separated by a predetermined distance therewith, and a second electrode provided on a portion of the diaphragm, the first and second electrodes forming capacitor, a vibration chamber having first and second walls, the first wall comprising a portion of the diaphragm and the second wall being disposed on the electrode;
• and
• applying a driving voltage signal to the capacitor to selectively charge and discharge the capacitor for deforming the diaphragm to thereby eject ink droplets from the nozzle for recording, wherein when the capacitor is charged the diaphragm is displaced to a first position, and wherein when the capacitor is discharged the diaphragm is displaced to a second position to eject ink droplets from the nozzle,
• wherein the vibration chamber is sealed and airtight,
• wherein the vibration chamber has a first volume V.sub.1 when said diaphragm is in the second position and a second volume V.sub.2 when said diaphragm is in the first position such that 2.ltoreq.V.sub.1 /.DELTA.V.ltoreq.8, wherein .DELTA.V is defined as the first volume V.sub.1 less the second volume V.sub.2.

A printing apparatus comprising:

• an inkjet head comprising:
• a plurality of nozzles,
• a plurality of ink paths, each of said ink paths being in communication with a respective one of said nozzles,
• a plurality of actuators, each of said actuators comprising a diaphragm provided at one part of a corresponding one of said ink paths,
• a plurality of electrodes, each of said electrodes provided in opposition to a corresponding one of said diaphragms and separated by a predetermined distance therewith, and
• a plurality of vibration chambers, each of said plurality of vibration chambers having first and second walls, said first wall comprising a portion of a corresponding one of said diaphragms and said second wall being disposed on a respective one of said electrodes;
• and
• drive means for selectively charging and discharging at least one of said actuators for deforming a respective one of said diaphragms by an electrostatic force to thereby eject ink droplets from a corresponding one of said nozzles for recording, wherein when said drive means charges said actuator, said diaphragm is displaced to a first position, and wherein when said drive means discharges said actuator said diaphragm is displaced to a second position to eject ink droplets from the corresponding one of said nozzles,
• wherein said plurality of vibration chambers are sealed and airtight,
• wherein each of said vibration chambers has a first volume V.sub.1 when said diaphragm is in the second position and a second volume V.sub.2 when said diaphragm is in the first position,
• wherein 2.ltoreq.V.sub.1 /.DELTA.V.ltoreq.8, and
• wherein .DELTA.V is defined as the first volume V.sub.1 less the second volume V.sub.2.