Abstract: According to the present invention, the occurrence of an ejection abnormality can be determined at an early stage by using a waveform for abnormal nozzle determination, before an image defect producing a visible density non-uniformity (stripe non-uniformity) occurs due to an ejection defect in an output image recorded by a drive signal having a recording waveform. Consequently, recording stability and throughput can both be achieved.

Abstract: A liquid ejection apparatus includes: a circuit control device including switches of which first ends are connected to pressure generating elements; a voltage waveform generating device configured to generate a voltage waveform to be supplied to second ends of the switches; and a switch control device which causes the switches to close and open. The voltage waveform has a waveform such that, when the switch is caused to close and open so that a portion of the voltage waveform is applied to the pressure generating element, a droplet is ejected from a nozzle corresponding to the pressure generating element to which the portion of the voltage waveform has been applied, whereas when a whole of the voltage waveform is applied to the pressure generating element, no droplet is substantially ejected from the nozzle corresponding to the pressure generating element to which the whole of the voltage waveform has been applied.

Abstract: A liquid ejection apparatus includes: a circuit control device including switches of which first ends are connected to pressure generating elements; a voltage waveform generating device configured to generate a voltage waveform to be supplied to second ends of the switches; and a switch control device which causes the switches to close and open. The voltage waveform has a waveform such that, when the switch is caused to close and open so that a portion of the voltage waveform is applied to the pressure generating element, a droplet is ejected from a nozzle corresponding to the pressure generating element to which the portion of the voltage waveform has been applied, whereas when a whole of the voltage waveform is applied to the pressure generating element, no droplet is substantially ejected from the nozzle corresponding to the pressure generating element to which the whole of the voltage waveform has been applied.

Abstract: A liquid droplet ejecting head includes: an ejector having a nozzle, a pressure chamber, and a drive element that applies pressure to a liquid inside the pressure chamber; and a controller that applies a drive waveform to the drive element. The controller vibrates a flow velocity of the liquid ejected from the nozzle in a first positive direction vibration mode for causing a leading end portion of the liquid droplet to be ejected from the nozzle toward the opposite side of the pressure chamber side; and a second positive direction vibration mode for adjusting the velocity of a trailing end portion of the liquid droplet. An interval between the first positive direction vibration mode and the second positive direction vibration mode is set so as to make the velocity of the trailing end portion of the columnar liquid droplet faster than the velocity of the leading end portion thereof.

Abstract: The ink-jet recording device of the present invention is provided with an ink-jet recording head that operates pressure waves on ink in a pressure chamber and ejects ink droplets from multiple nozzles; a wiper that wipes a nozzle face of the ink-jet recording head; a drive waveform applying component that applies a drive waveform to a drive element so that ink droplets are not ejected and ink floods the nozzle face; and a control component that, when performing wiping, drives the drive waveform applying component prior to initiating wiping and actuates the wiper in a state where the ink is flooded on the nozzle face.

Abstract: A liquid-drop-ejecting recording head carries out image recording by applying a jetting pulse having a binary digital driving waveform to a piezoelectric element, providing a vibration wave to liquid accommodated in an accommodating chamber, and ejecting a liquid drop from a eject opening. The liquid-drop-ejecting recording head classifies each pixel in accordance with density data thereof. When recording a pixel belonging to a high density range, plural jetting pulses, whose pulse width is ½ times a natural vibration period of a liquid flow at a flow path of the liquid, are applied within a single printing cycle at an interval which is set in advance in accordance with density data of the pixel.

Abstract: A liquid-drop-ejecting recording head carries out image recording by applying a jetting pulse having a binary digital driving waveform to a piezoelectric element, providing a vibration wave to liquid accommodated in an accommodating chamber, and ejecting a liquid drop from a eject opening. The liquid-drop-ejecting recording head classifies each pixel in accordance with density data thereof. When recording a pixel belonging to a high density range, plural jetting pulses, whose pulse width is ½ times a natural vibration period of a liquid flow at a flow path of the liquid, are applied within a single printing cycle at an interval which is set in advance in accordance with density data of the pixel.

Abstract: The ink-jet recording device of the present invention is provided with an ink-jet recording head that operates pressure waves on ink in a pressure chamber and ejects ink droplets from multiple nozzles; a wiper that wipes a nozzle face of the ink-jet recording head; a drive waveform applying component that applies a drive waveform to a drive element so that ink droplets are not ejected and ink floods the nozzle face; and a control component that, when performing wiping, drives the drive waveform applying component prior to initiating wiping and actuates the wiper in a state where the ink is flooded on the nozzle face.

Abstract: A driving method for an ink jet printing head includes a vibration application step and an ink refresh operation step. In the vibration application step, small vibrations, which do not cause ink drop discharge from nozzles of the ink jet printing head, are applied to pressure-generation chambers of the ink jet printing head corresponding to nozzles which are not executing ink drop discharge. In the ink refresh operation step, ink refresh operation, for removing the ink in the nozzles and replacing the ink with fresh ink, is periodically executed according to a refresh operation cycle which is appropriately set based on the temperature and/or humidity measured around the ink jet printing head. The ink refresh operation is executed by means of forcible ink drop discharge from the nozzles, ink suction by a pump, etc. For example, the refresh operation cycle is set shorter as the temperature around the ink jet printing head gets lower and as the humidity around the ink jet printing head gets lower.

Abstract: In an ink jet recording head, an ink pool has a main flow path communicating with an ink supply port and a plurality of branch flow paths branching from the main flow path. Each ejector has a pressure chamber, a pressure generating unit and a nozzle. The pressure chamber communicates with the corresponding one of the branch flow paths. The pressure generating unit generates a pressure wave in ink charged into the pressure chamber. The nozzle ejects the ink from the pressure chamber compressed by the pressure wave. At least one wall surface forming each of the branch flow paths is formed of a damper member elastically deformable in accordance with the change of pressure in the branch flow path.

Abstract: The present invention provides an ink jet recording head drive method for applying a drive voltage to an electro-mechanical converter which changes a pressure within a pressure generation chamber filled with ink, so that an ink droplet is ejected from a nozzle communicating with the pressure generation chamber, wherein the drive voltage has a voltage waveform including: a first voltage change process for increasing a volume of the pressure generation chamber so as to pull the ink meniscus at the nozzle opening toward the pressure generation chamber; and a second voltage change process for decreasing the volume of the pressure generation chamber, so as to eject an ink droplet, and wherein the first voltage change process is preceded by a preparatory voltage change process for slightly pulling an ink meniscus from the nozzle opening toward the pressure generation chamber.

Abstract: An ink jet printing head includes a common ink channel and a plurality of ejectors (each of which includes a nozzle and a pressure generation chamber which is filled with ink supplied from the common ink channel) which are connected to the common ink channel for ejecting ink drops. The common ink channel is provided with an air damper, and acoustic capacitance Cp of the common ink channel per ejector is set based on acoustic capacitance Cn of the nozzle and acoustic capacitance Cc of the pressure generation chamber. For example, the acoustic capacitance Cp of the common ink channel per ejector is set so as to satisfy two conditions: Cp>Cn and Cp>20 Cc.

Abstract: In an ink jet recording head, an ink pool has a main flow path communicating with an ink supply port and a plurality of branch flow paths branching from the main flow path. Each ejector has a pressure chamber, a pressure generating unit and a nozzle. The pressure chamber communicates with the corresponding one of the branch flow paths. The pressure generating unit generates a pressure wave in ink charged into the pressure chamber. The nozzle ejects the ink from the pressure chamber compressed by the pressure wave. At least one wall surface forming each of the branch flow paths is formed of a damper member elastically deformable in accordance with the change of pressure in the branch flow path.

Abstract: An ink jet printing head includes a common ink channel and a plurality of ejectors (each of which includes a nozzle and a pressure generation chamber which is filled with ink supplied from the common ink channel) which are connected to the common ink channel for ejecting ink drops. The common ink channel is provided with an air damper, and acoustic capacitance Cp of the common ink channel per ejector is set based on acoustic capacitance Cn of the nozzle and acoustic capacitance Cc of the pressure generation chamber. For example, the acoustic capacitance Cp of the common ink channel per ejector is set so as to satisfy two conditions: Cp>Cn and Cp>20 Cc.