Abstract: A conveyance unit continually conveys sheets of the number of continual prints. A head control section controls ejection of ink droplets from inkjet heads in such a way that there are produced image dots which make up an image to be printed on each of the sheet every time the sheet is conveyed and flushing dots corresponding to flushing dot candidates, among flushing dot candidates for flushing patterns included in a flushing pattern group determined from the continual print count, which are placed at locations where the image dots are not to be produced.

Abstract: A inkjet recording apparatus includes a first inkjet head which ejects color ink having one of a hydrophobic property and an aqueous property; a second inkjet head which ejects colorless ink having the remaining the other property; and an ejection controller which controls the first inkjet head to eject the color ink on an image region and controls the second inkjet head to eject the colorless ink on an ejection region contacting the image region with a boundary therebetween. The ejection controller controls the first and second inkjet heads so that the colorless ink ejected from the second inkjet head reaches a second minute segment in the ejection region, the second minute segment adjacent to a first minute segment in the image region with the boundary interposed therebetween, before the color ink ejected from the first inkjet head reaches the first minute segment in the image region.

Abstract: A liquid ejection head includes a passage unit and an actuator. A nozzle for ejecting liquid and a common liquid chamber are formed in the passage unit. An individual liquid passage formed in the passage unit includes a first passage a pressure chamber, a second passage, and a restricted passage. The first passage communicates between the nozzle and the pressure chamber. The second passage communicates between the pressure chamber and the restricted passage. The restricted passage is smaller than the second passage in the sectional area perpendicular to the flow of the liquid. The actuator can selectively take a first state in which the volume of the pressure chamber is V1 and a second state in which the volume of the pressure chamber is V2 larger than V1. The actuator changes from the first state into the second state and then returns to the first state to eject the liquid from the nozzle.

Abstract: A printer is provided with an ink jet head and a controller. The ink jet head prints on a print medium by discharging ink. The ink jet head comprises a plurality of units. Each unit comprises a nozzle for discharging ink, a pressure chamber communicating with the nozzle, and a piezoelectric element facing the pressure chamber. The piezoelectric elements form at least two element lines. Each element line is formed by at least two piezoelectric elements aligned in a first direction. Each element line is aligned in a sec direction which is different from the first direction. The controller controls the ink jet head to print on the print medium by changing voltage applied to each piezoelectric element of the ink jet head. The controller controls timings at which the controller changes voltage applied to each piezoelectric element by the element line.

Abstract: An ink-jet recording apparatus of one aspect of the invention comprises nozzles are arranged on an ink ejection surface in a matrix in a first direction in which a recording medium is conveyed and a second direction orthogonal to the first direction. The plurality of nozzles are grouped into a plurality of nozzle sets, each of the plurality of nozzle sets includes nozzles arranged along the second direction. The plurality of nozzle sets are spaced from one another in the first direction by first distances, each of the first distances is an integral multiple of a distance that is obtained by multiplying a unit distance by 2n-1. The unit distance corresponds to a highest resolution among first resolutions with respect to the first direction of an image to be formed on the recording medium.

Abstract: A printer is provided with an ink jet head and a controller. The ink jet head prints on a print medium by discharging ink. The ink jet head comprises a plurality of units. Each unit comprises a nozzle for discharging ink, a pressure chamber communicating with the nozzle, and a piezoelectric element facing the pressure chamber. The piezoelectric elements form at least two element lines. Each element line is formed by at least two piezoelectric elements aligned in a first direction. Each element line is aligned in a sec direction which is different from the first direction. The controller controls the ink jet head to print on the print medium by changing voltage applied to each piezoelectric element of the ink jet head. The controller controls timings at which the controller changes voltage applied to each piezoelectric element by the element line.

Abstract: It is possible to minimize the amplitude of residual vibration of a piezoelectric actuator so as to maintain the image quality of a formed image at a preferable level in case of an ink jet head, for example. A liquid discharge device includes a control unit (14) for ON/OFF control of a drive voltage applied to the piezoelectric actuator. The control unit (14) has a micro vibration control section (23) for drive-controlling a drive circuit so as to micro-vibrate the piezoelectric actuator in a waiting state not discharging a liquid drop from a nozzle, in a range that no liquid drop is discharged in the nozzle. The piezoelectric ink jet head includes the liquid discharge device. The drive method is for micro-vibrating the piezoelectric actuator in the waiting state not discharging a liquid drop from the nozzle, in a range that no liquid drop is discharged from the nozzle.

Abstract: A liquid ejection apparatus having liquid ejection heads extending in a particular direction, and each liquid ejection head has an ejection surface with ejection ports configured to eject a liquid, a supply port to which liquid is supplied, and a flow path formed in the liquid ejection head. The flow path is configured to place the ejection ports and the supply port in fluid communication. The liquid ejection heads are positioned at predetermined intervals in a direction perpendicular to the particular direction, and for each liquid ejection head, the supply port of one liquid ejection head is in a different location in the particular direction, than all of the liquid ejection heads adjacent to the one liquid ejection head in the perpendicular direction.

Abstract: A printer is provided with an ink jet head and a controller. The ink jet head prints on a print medium by discharging ink. The ink jet head comprises a plurality of units. Each unit comprises a nozzle for discharging ink, a pressure chamber communicating with the nozzle, and a piezoelectric element facing the pressure chamber. The piezoelectric elements form at least two element lines. Each element line is formed by at least two piezoelectric elements aligned in a first direction. Each element line is aligned in a sec direction which is different from the first direction. The controller controls the ink jet head to print on the print medium by changing voltage applied to each piezoelectric element of the ink jet head. The controller controls timings at which the controller changes voltage applied to each piezoelectric element by the element line.

Abstract: A conveyance unit continually conveys sheets of the number of continual prints. A head control section controls ejection of ink droplets from inkjet heads in such a way that there are produced image dots which make up an image to be printed on each of the sheet every time the sheet is conveyed and flushing dots corresponding to flushing dot candidates, among flushing dot candidates for flushing patterns included in a flushing pattern group determined from the continual print count, which are placed at locations where the image dots are not to be produced.

Abstract: There is provided an inkjet head printing device, which includes an inkjet head that has an ink flow channel unit including a plurality of nozzles for ejecting ink and a plurality of pressure chambers respectively provided for the plurality of nozzles, and has a piezoelectric actuator unit including a plurality of electrodes. The inkjet head further includes a pulse controller that generates a plurality of types of ejection pulse patterns having different phases and drives the plurality of electrodes corresponding to the plurality of nozzles which are to eject the ink using the plurality of types of ejection pulse patterns.

Abstract: An ink jet printer is provided with a passage unit, an actuator, and a pulse applying device. The passage unit comprises a nozzle, a pressure chamber, and an ink passage located between the nozzle and the pressure chamber. The actuator faces the pressure chamber and comprises a first electrode, a second electrode to which a reference potential can be applied, and a piezoelectric element located between the first electrode and the second electrode. The pulse applying device is capable of applying a first voltage pulse to the first electrode such that the nozzle discharges an ink droplet, and a second voltage pulse to the first electrode such that the nozzle does not discharge the ink droplet. A voltage change on a leading edge and/or a trailing edge of the second voltage pulse is greater than a voltage change on a leading edge and/or a trailing edge of the first voltage pulse.

Abstract: An actuator can selectively switch a volume of a pressure chamber between a first state V1 and a second state V2, which is greater than V1. The actuator changes from the first state into the second state and then changes back into the first state to eject ink from an ejection port. A controller controls the actuator such that To/Tc falls within a range from 0.51 to 0.54. To represents the time period between time the actuator starts to change from the first state into the second state, to a time the actuator starts to change from the second state into the first state. Tc represents the period of proper oscillation of ink filling up the individual ink passage. The actuator is controlled so that a variation in ink ejection speed is prevented from being too large relative to the variation in the degree of deformation of the actuator.

Abstract: In order to preserve good droplet discharge efficiency in a droplet discharge device, a plurality of timings are set within a period in which a plurality of droplets are to be discharged to a target position. Consecutive timings are divided by a cycle time of pressure wave that is generated inside a pressure chamber by transmitting a signal to an actuator. When a plurality of signals are applied to the actuator at consecutive timings, the peak of the pressure wave and the application of the signals are synchronous, and the droplet discharge efficiency will be improved. However, the consecutive number of timings at which the consecutive signals are transmitted is limited to a predetermined number. In this way, the pressure inside the pressure chamber can be prevented from becoming too high.

Abstract: An ink jet printer has an ink jet head comprising a nozzle that discharges an ink droplet toward a print medium, and an actuator that makes the nozzle discharge the ink droplet when a pulse signal is applied to the actuator. An applying device can apply at least two kinds of pulse signals to the actuator. The pulse width of each kind of pulse signal mutually differs. A first storage stores at least two kinds of base pulse widths. Each kind of base pulse width mutually differs and corresponds with a different kind of pulse signal. An inputting device inputs a predetermined value which is stored in the second storage. The applying device determines a pulse width of each kind of pulse signal by multiplying the corresponding base pulse width stored in the first storage by the predetermined value stored in the second storage.

Abstract: A inkjet recording apparatus includes a first inkjet head which ejects color ink having one of a hydrophobic property and an aqueous property; a second inkjet head which ejects colorless ink having the remaining the other property; and an ejection controller which controls the first inkjet head to eject the color ink on an image region and controls the second inkjet head to eject the colorless ink on an ejection region contacting the image region with a boundary therebetween. The ejection controller controls the first and second inkjet heads so that the colorless ink ejected from the second inkjet head reaches a second minute segment in the ejection region, the second minute segment adjacent to a first minute segment in the image region with the boundary interposed therebetween, before the color ink ejected from the first inkjet head reaches the first minute segment in the image region.

Abstract: It is possible to minimize the amplitude of residual vibration of a piezoelectric actuator so as to maintain the image quality of a formed image at a preferable level in case of an ink jet head, for example. A liquid discharge device includes a control unit (14) for ON/OFF control of a drive voltage applied to the piezoelectric actuator. The control unit (14) has a micro vibration control section (23) for drive-controlling a drive circuit so as to micro-vibrate the piezoelectric actuator in a waiting state not discharging a liquid drop from a nozzle, in a range that no liquid drop is discharged in the nozzle. The piezoelectric ink jet head includes the liquid discharge device. The drive method is for micro-vibrating the piezoelectric actuator in the waiting state not discharging a liquid drop from the nozzle, in a range that no liquid drop is discharged from the nozzle.

Abstract: An aspect of the invention provides an inkjet printer including: an inkjet head and a controller. The inkjet head moves relative to a recording medium to perform printing. The inkjet head includes, a flow path unit including plural pressure chambers respectively communicating with plural ink ejection ports that ejects ink droplets toward the recording medium, and a piezoelectric actuator configured to take a first state and a second state. The controller supplies a drive pulse signal to the piezoelectric actuator in order to repeat an operation in which the piezoelectric actuator transits from the first state to the second state and returns to the first state, for enabling the corresponding ink ejection port to eject a plurality of ink droplets. The controller supplies the drive pulse signal so that timings of the transition and the return satisfy some relationships.

Abstract: A liquid ejection apparatus having liquid ejection heads extending in a particular direction, and each liquid ejection head has an ejection surface with ejection ports configured to eject a liquid, a supply port to which liquid is supplied, and a flow path formed in the liquid ejection bead. The flow path is configured to place the ejection ports and the supply port in fluid communication. The liquid ejection heads are positioned at predetermined intervals in a direction perpendicular to the particular direction, and for each liquid ejection head, the supply port of one liquid ejection head is in a different location in the particular direction, than all of the liquid ejection heads adjacent to the one liquid ejection head in the perpendicular direction.

Abstract: An ink-jet recording apparatus of one aspect of the invention comprises nozzles are arranged on an ink ejection surface in a matrix in a first direction in which a recording medium is conveyed and a second direction orthogonal to the first direction. The plurality of nozzles are grouped into a plurality of nozzle sets, each of the plurality of nozzle sets includes nozzles arranged along the second direction. The plurality of nozzle sets are spaced from one another in the first direction by first distances, each of the first distances is an integral multiple of a distance that is obtained by multiplying a unit distance by 2n-1. The unit distance corresponds to a highest resolution among first resolutions with respect to the first direction of an image to be formed on the recording medium.