EP2837497B1 - Liquid droplet ejection apparatus and method for recovering nozzle of liquid droplet ejection apparatus - Google Patents
Liquid droplet ejection apparatus and method for recovering nozzle of liquid droplet ejection apparatus Download PDFInfo
- Publication number
- EP2837497B1 EP2837497B1 EP14172583.8A EP14172583A EP2837497B1 EP 2837497 B1 EP2837497 B1 EP 2837497B1 EP 14172583 A EP14172583 A EP 14172583A EP 2837497 B1 EP2837497 B1 EP 2837497B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- ink
- nozzle
- micro
- liquid droplet
- head
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000007788 liquid Substances 0.000 title claims description 196
- 238000000034 method Methods 0.000 title claims description 47
- 239000002245 particle Substances 0.000 claims description 102
- 239000007787 solid Substances 0.000 claims description 98
- 238000001514 detection method Methods 0.000 claims description 75
- 238000007639 printing Methods 0.000 claims description 38
- 230000005484 gravity Effects 0.000 claims description 35
- 239000002612 dispersion medium Substances 0.000 claims description 33
- 230000008569 process Effects 0.000 claims description 31
- 239000002609 medium Substances 0.000 claims description 18
- 238000012423 maintenance Methods 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 239000000976 ink Substances 0.000 description 236
- 238000004062 sedimentation Methods 0.000 description 43
- 239000000919 ceramic Substances 0.000 description 17
- 238000005192 partition Methods 0.000 description 15
- 238000011109 contamination Methods 0.000 description 11
- 238000011084 recovery Methods 0.000 description 9
- 239000003086 colorant Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 5
- 239000012530 fluid Substances 0.000 description 5
- 230000005499 meniscus Effects 0.000 description 5
- 239000000049 pigment Substances 0.000 description 5
- 230000002265 prevention Effects 0.000 description 5
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 239000004744 fabric Substances 0.000 description 2
- 230000033001 locomotion Effects 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 239000002985 plastic film Substances 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/135—Nozzles
- B41J2/165—Prevention or detection of nozzle clogging, e.g. cleaning, capping or moistening for nozzles
- B41J2/16517—Cleaning of print head nozzles
- B41J2/1652—Cleaning of print head nozzles by driving a fluid through the nozzles to the outside thereof, e.g. by applying pressure to the inside or vacuum at the outside of the print head
- B41J2/16526—Cleaning of print head nozzles by driving a fluid through the nozzles to the outside thereof, e.g. by applying pressure to the inside or vacuum at the outside of the print head by applying pressure only
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/015—Ink jet characterised by the jet generation process
- B41J2/04—Ink jet characterised by the jet generation process generating single droplets or particles on demand
- B41J2/045—Ink jet characterised by the jet generation process generating single droplets or particles on demand by pressure, e.g. electromechanical transducers
- B41J2/04501—Control methods or devices therefor, e.g. driver circuits, control circuits
- B41J2/0458—Control methods or devices therefor, e.g. driver circuits, control circuits controlling heads based on heating elements forming bubbles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/015—Ink jet characterised by the jet generation process
- B41J2/04—Ink jet characterised by the jet generation process generating single droplets or particles on demand
- B41J2/045—Ink jet characterised by the jet generation process generating single droplets or particles on demand by pressure, e.g. electromechanical transducers
- B41J2/04501—Control methods or devices therefor, e.g. driver circuits, control circuits
- B41J2/04581—Control methods or devices therefor, e.g. driver circuits, control circuits controlling heads based on piezoelectric elements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/015—Ink jet characterised by the jet generation process
- B41J2/04—Ink jet characterised by the jet generation process generating single droplets or particles on demand
- B41J2/045—Ink jet characterised by the jet generation process generating single droplets or particles on demand by pressure, e.g. electromechanical transducers
- B41J2/04501—Control methods or devices therefor, e.g. driver circuits, control circuits
- B41J2/04588—Control methods or devices therefor, e.g. driver circuits, control circuits using a specific waveform
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/015—Ink jet characterised by the jet generation process
- B41J2/04—Ink jet characterised by the jet generation process generating single droplets or particles on demand
- B41J2/045—Ink jet characterised by the jet generation process generating single droplets or particles on demand by pressure, e.g. electromechanical transducers
- B41J2/04501—Control methods or devices therefor, e.g. driver circuits, control circuits
- B41J2/04596—Non-ejecting pulses
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/135—Nozzles
- B41J2/165—Prevention or detection of nozzle clogging, e.g. cleaning, capping or moistening for nozzles
- B41J2/16585—Prevention or detection of nozzle clogging, e.g. cleaning, capping or moistening for nozzles for paper-width or non-reciprocating print heads
Definitions
- the present invention relates to a liquid droplet ejection apparatus and a method for recovering a nozzle of the liquid droplet ejection apparatus, and more particularly to a liquid droplet ejection apparatus that can suppress sedimentation of solid particles contained in an ink and stably eject liquid droplets for a long time and a method for recovering a nozzle of the liquid droplet ejection apparatus.
- a liquid droplet ejection apparatus that performs printing by ejecting liquid droplets from a head is generally used for various industrial purposes as an inkjet printer.
- Applications of this industrial inkjet increases year by year, and the inkjet printer is used for not only performing printing on paper sheets, fabric, plastic sheets, and others but also performing printing a design on a surface of a ceramic tile in recent years. Accordingly, performance that enables stably ejecting various kinds of inks for a long time has been demanded with respect to the liquid droplet ejection apparatus.
- Patent Document 1 a technology that circulates the ink by using a pressure difference between a head and an ink tank has been suggested.
- the ink on the ink side that is circulated by this technology is an ink in a common ink chamber that exclusively supplies the ink to respective ink chambers in common, and the ink supplied to the respective ink chamber cannot be circulated. Therefore, at a print pause time, the sedimentation of the solid particles that occurs in the ink chambers cannot be suppressed.
- Patent Document 2 As a countermeasure for nozzle clogging during the printing pause, there has been known a technology that applies a preliminary waveform to each ink chamber to vibrate a meniscus immediately before restarting ejection and allows the ink in the ink chambers to flow (Patent Document 2) .
- Patent Document 2 a technology that applies a preliminary waveform to each ink chamber to vibrate a meniscus immediately before restarting ejection and allows the ink in the ink chambers to flow.
- Patent Document 2 a technology that applies a preliminary waveform to each ink chamber to vibrate a meniscus immediately before restarting ejection and allows the ink in the ink chambers to flow.
- Patent Document 2 As a countermeasure for nozzle clogging during the printing pause, there has been known a technology that applies a preliminary waveform to each ink chamber to vibrate a meniscus immediately before restarting ejection and allows the ink in the ink chambers to flow.
- Patent Document 3 there has been also known detecting viscosity of an ink and adjusting intensity of micro-vibration and an amount of liquid droplets at the time of discharging an ink.
- Patent Document 3 this technology prevents nozzle clogging caused due to evaporation of a liquid and an increase in viscosity of the ink, and does not solve a problem caused by the sedimentation of the solid particles contained in the ink.
- US 2009/160887 A1 discloses a liquid droplet ejection head comprising an ejector, a liquid viscosity-increase prevention structure and a liquid viscosity-increase prevention controller.
- the ejector includes a nozzle for ejecting a liquid droplet, a pressure chamber communicating with the nozzle through a communication path, and an actuator for applying pressure to a liquid in the pressure chamber.
- the liquid viscosity-increase prevention structure prevents an increase of viscosity of the liquid in the ejector.
- the liquid viscosity-increase prevention controller changes the operation frequency of the liquid viscosity-increase prevention structure between when the liquid droplet is ejected from the nozzle and when ejection of the liquid droplet is paused and no liquid droplet is being ejected from the nozzle.
- US 2002/171704 A1 discloses a liquid jetting apparatus including a head member having a nozzle, a supporting member that can support a medium, a scanning mechanism that can cause the head member to relatively move with respect to the medium, and a liquid jetting unit that can jet liquid from the nozzle.
- An area storing unit stores a relative area to which liquid can be jetted from the nozzle while the head member is caused to relatively move by the scanning mechanism.
- An out-of-jetting micro-vibrating-area setting unit can set out-of-jetting micro-vibrating areas before and after the relative area.
- a micro-vibrating unit causes liquid in the nozzle to minutely vibrate.
- An out-of-jetting micro-vibrating controlling unit causes the micro-vibrating unit to operate when the head member is located in the out-of-jetting micro-vibrating areas, while the head member is caused to relatively move by the scanning mechanism, based on the out-of-jetting micro-vibrating areas and head-position information.
- EP 2 127 882 A1 discloses a fluid ejecting apparatus that ejects fluid including a pressure chamber that is filled with the fluid, a pressure generating element that deforms a wall face of the pressure chamber to change a volume of the pressure chamber, a nozzle that is in fluid communication with the pressure chamber and that is used for ejecting the fluid, and a control unit that generates a drive pulse for controlling the pressure generating element.
- the liquid droplet ejection apparatus that can effectively eliminate the sedimentation of solid particles contained in an ink and stably eject liquid droplets for a long time.
- FIG. 1 is a perspective view showing an example of a liquid droplet ejection apparatus
- FIG. 2 is a cross-sectional view showing an example of a head.
- reference numeral 100 denotes a liquid droplet ejection apparatus; 1, a head; and 2, a conveyance belt.
- ceramic tiles C as recording mediums are mounted at intervals on a conveyance surface 2a of a conveyance belt 2 that is driven to rotate in one direction, and they are conveyed in an arrow direction in the drawing.
- a plurality of nozzles 12 are aligned along an X direction in the drawing parallel to a width direction of the conveyance belt 2, and nozzle surfaces are arranged to be vertically downward directed so that they face the conveyance surface 2a.
- a ceramic ink containing, e.g., ceramic particles having specific gravity higher than that of dispersion medium is ejected as solid particles from the respective nozzles 12 to a print region on a front surface of each ceramic tile C that is conveyed at a fixed speed by the conveyance belt 2 based on print data, thereby forming a predetermined image.
- a plurality of ink chambers 11 are aligned along the X direction.
- all the ink chambers 11 are ink chambers that can eject liquid droplets from the nozzles 12 provided in accordance with the respective ink chambers 11 when the ink in a common ink chamber 13 provided to communicate with the respective ink chambers 11 is supplied thereto.
- each partition wall 14 that separates the neighboring ink chambers 11, 11 from each other is formed of a piezoelectric element.
- Drive electrodes (not shown) are formed on surfaces of the partition walls 14 facing the inside of the ink chambers 11.
- each partition wall 14 deforms, and a capacity of each ink chamber 11 changes.
- this change in capacity increases to eject the ink in each ink chamber 11 from each nozzle 12 formed on a nozzle plate 15, ejection energy is given to the ink in each ink chamber 11, and liquid droplets are ejected from each nozzle 12.
- the partition walls 14 having the drive electrodes formed thereon constitute energy giving means for giving the ink in the ink chambers 11 the energy.
- the ink to be used in the present invention contains dispersion medium as well as solid particles having higher specific gravity than that of the dispersion medium.
- the dispersion medium is out of the question.
- the solid particles there are ceramic particles in the ceramic ink, pigment particles of a titanium oxide, and others.
- the specific gravity difference between the dispersion medium and the solid particles in the present invention is 0.2 or more since an effect of the present invention can be considerably provided, which is preferable.
- the ink that does not volatilize by drying at an ordinary temperature under an ordinary pressure is used.
- the ink that does not volatilize means an ink in which the content of a material, whose steam pressure at an ordinary temperature is higher than that of water, is 10% or less or preferably 5% or less.
- Such an ink does not have a problem of an increase in viscosity due to evaporation of a volatile component that can be observed when a volatile ink such as an aqueous ink is used at the time of use.
- an ink for example, there are a UV ink, an oil ink, and others.
- FIG. 3 is a block diagram showing an outline configuration of the inside of the liquid droplet ejection apparatus 100.
- Reference numeral 101 denotes a CPU that controls the entire liquid droplet ejection apparatus 100; 102, a print data memory that stores print data to be formed in a print region on the surface of each ceramic tile C; 103, an encoder that detects a moving length of the conveyance belt 2; 104, a belt conveyance motor that drives the conveyance belt 2 to rotate; 105, a head driver that gives a pulse to the drive electrodes of the head 1 to deform the partition walls 14; 106, a drive pulse generation unit that is provided in the head driver 105 and generates a drive pulse as a drive signal to be supplied to the head 1; 107, a micro-vibration control unit that is provided in the CPU 101 and controls a micro-vibration operation for micro-vibrating the ink in the ink chambers 11; and 108, an ejection control unit that is provided in the CPU 101 and controls an ejection operation of ejecting the ink in the ink chambers 11.
- the micro-vibration control unit 107 controls drive of the head 1 through the head driver 105 so as to perform a micro-vibration operation for micro-vibrating the ink in the ink chambers 11 and providing the solid particles with kinetic energy to facilitate dispersion.
- this micro-vibration control unit 107 constitutes micro-vibrating means.
- the ejection control unit 108 controls drive of the head 1 through the head driver 105 so as to perform an ejection operation for forcibly ejecting the ink in the ink chambers 11 and replacing the ink in the ink chambers 11 with a new ink.
- the micro-vibration control unit 107 and the ejection control unit 108 constitute refreshing means.
- a pulse generated by the drive pulse generating unit 106 includes an ejection pulse P1 for ejecting liquid droplets from the nozzles 12 like an example shown in FIG. 4(a) and a micro-vibration pulse P2 for micro-vibrating the ink in the ink chambers 11 so as not to eject liquid droplets from the nozzles 12 like an example shown in FIG. 4(b) .
- the drive pulse generating unit 106 selects one of these drive pulses in accordance with an instruction from the CPU 101 and applies the drive pulse to the drive electrodes formed on the partition walls 104 of the head 1.
- sedimentation of the solid particles may possibly cause an ejection failure such as nozzle clogging if a period during which ejection from the nozzle 12 pauses when the head 1 is in the print region or a small period during which ejection pauses when the head 1 is in the non-print region has been passed.
- refresh for ejecting liquid droplets from the respective nozzles 12 to eject the ink is performed under control of the CPU 101, thereby stabilizing the ejection.
- the non-print region is a region which deviates from the recording medium has no print data and in which printing based on this print data is not performed.
- the head 1 print regions and non-print regions alternately fed.
- a space between the ceramic tiles C, C continuously mounted on the conveyance surface 2a at an interval is the non-print region where printing based on print data is not carried out.
- Arrival of the head 1 at the non-print region is detected by a moving length of the conveyance belt 2 detected by the encoder 103.
- the refresh of the head 1 executed by the CPU 101 is performed by the micro-vibration operation under control of the micro-vibration control unit 107 and the ejection operation performed after this micro-vibration operation under control of the ejection control unit 108. That is, when the head 1 is present in the non-print region during a period from passage of one ceramic tile C through a position immediately below the head 1 to arrival of the subsequent ceramic tile C at the position immediately below the head 1, the refresh is constituted of the micro-vibration operation for applying the plurality of micro-vibration pulses P2 to the drive electrodes of the partition walls 14 and micro-vibrating the ink in the ink chambers 11 so as not to eject the liquid droplets from the nozzles 12 under control of the micro-vibration control unit 107 and the ejection operation for applying the plurality of ejection pulses P1 to the drive electrodes of the partition walls 14 after effecting the micro-vibration operation and ejects the liquid droplets from the nozzles 12 to provide a
- the capacity of the ink chamber 11 means a capacity of an ink channel between a boundary relative to the common ink chamber 13 and an end opening portion of each nozzle 12. Therefore, this capacity does not include a capacity in the common ink chamber 13.
- this capacity is a capacity of a space with a distance D that serves as an ink channel from an opening portion 11a of the ink chamber 11 that is a boundary relative to the common ink chamber 13 between both the partition walls 14 defining each ink chamber 11 to an end opening portion 12a of the nozzle 12 that is opened in a surface (a nozzle surface) of the nozzle plate 15.
- the liquid droplet amount that is equal to or greater than the capacity of the ink chamber 11 can be defined by the total number of times of applying the ejection pulses P1.
- the solid particles is provided with kinetic energy, and hence the settled and aggregated solid particles in the ink before ejection are apt to be dispersed, thereby smoothly discharging the ink from the nozzles 12 by the energy given at the time of subsequent ejection. Therefore, the settled solid particles do not remain in the ink chambers 11, and a total amount of the ink in the ink chambers 11 can be efficiently replaced.
- FIG. 6 shows an example of an application pattern of the ejection pulse P1 and the micro-vibration pulse P2 at the time of performing the refresh.
- a micro-vibration pulse applying operation for continuously applying the plurality of micro-vibration pulses P2 is first continued for a predetermined time t1, and then an ejection pulse applying operation for continuously applying the plurality of ejection pulses P1 is continued for a predetermined time t2.
- the micro-vibration pulse applying operation of the time t1 and the ejection pulse applying operation of the time t2 are continuously alternately repeated three times.
- the liquid droplets can be ejected so that a total liquid droplet amount of the liquid droplets ejected by the ejection pulse applying operation performed more than once can be a liquid droplet amount equal to or above the capacity of the ink chamber 11.
- the liquid droplets can be ejected so as to provide an amount of liquid droplets that is equal to or greater than the capacity of each ink chamber 11 in accordance with each single ejection pulse applying operation in one non-print region. In this case, a total amount of the ink is replaced more than once in one non-print region. According to this operation, since a flowing amount of the ink around the ink chambers 11 including the common ink chamber 13 in the head 1 increases, an effect for enabling supply of the ink in which the solid particles are uniformly dispersed into the ink chambers 11 can be improved.
- the number of times of occurrence of the micro-vibration pulse applying operation of the time t1 and the ejection pulse applying operation of the time t2 in one non-print region is out of the question as long as the micro-vibration pulse applying operation is carried out immediately before the ejection pulse applying operation.
- three sets of the time t1 of the micro-vibration pulse P2 are all uniform and three sets of the time t2 of the respective ejection pulse P1 are also uniform, but the time t1 and the time t2 may be set to be non-uniform in each applying operation. That is, the number of times of applying the ejection pulse P1 or the micro-vibration pulse P2 in each applying operation may differ in accordance with each applying operation.
- the refresh that the micro-vibration operation and the ejection operation are carried out can be effected every time the head 1 reaches the non-print region, there might be a case that sedimentation of the solid particles in the ink in the ink chambers 11 does not substantially advance like a situation where a large amount of liquid droplets are continuously ejected from the nozzle 12 in the print region or where a specific gravity difference of the dispersion medium and the solid particles is relatively small depending on a type of ink.
- the ink ejection operation is carried out every time the head 1 reaches the non-print region, the ink is wastefully consumed.
- the liquid droplets containing the solid particles is apt to produce a satellite, there is concern that the generated satellite turns to mist and scatters at the time of ejection, leading to contamination of the periphery.
- the CPU 101 select whether the refresh is to be carried out in accordance with a sedimentation state, i.e., a state of progress of sedimentation of the solid particles in the ink in the ink chambers 11 when the head 1 is present in the non-print region.
- a sedimentation state i.e., a state of progress of sedimentation of the solid particles in the ink in the ink chambers 11 when the head 1 is present in the non-print region.
- an ejection speed of the liquid droplets ejected from the nozzles 12 is lowered as a quantity of the solid particles contained in the liquid droplets increases. Therefore, it is possible to estimate of a state of progress of sedimentation of the solid particles in the ink near the nozzles 12 in the ink chamber 11.
- FIG. 7 shows a liquid droplet speed detection apparatus 3 which is an example of detecting means for detecting an ejection speed of the liquid droplets.
- This liquid droplet speed detection apparatus 3 is configured to operate in response to an instruction from the CPU 101 and transmit a result to the CPU 101 as shown in FIG. 3 .
- the liquid droplet speed detection apparatus 3 has a light projection unit 31 formed of an LED or a laser that emits detection light L and a light receiving unit 32 formed of a photosensor or the like that receives this detection light L, and the liquid droplet speed detection apparatus 3 is arranged near a position immediately below nozzles 12 in such a manner that an optical axis of the detection light L becomes parallel to the X direction as an alignment direction of the nozzles 12 and also becomes parallel to the nozzle surface. As a result, the liquid droplet ejected from each nozzle 12 crosses the detection light L, and a shade when the liquid droplet a passes is captured by the light receiving unit 32.
- the liquid droplet speed detection apparatus 3 calculates an ejection speed of the liquid droplet a from a time required to capture a shade of the liquid droplet a from application of the ejection pulse P1 and a distance to the optical axis of the detection light L from the nozzle 12.
- a threshold value indicative of a lower limit of a preferred ejection speed of the liquid droplet a is preset to one of the CPU 101 and the liquid droplet speed detection apparatus 3.
- the ejection speed of the liquid droplet a detected in a case where the head 1 is present in the non-print region falls below this threshold value, sedimentation of the solid particles in the ink in the corresponding ink chamber 11 is progressing, and it is possible to determine that the refresh should be carried out.
- FIG. 8 shows an example of a flow for detecting a speed of the liquid droplet a by the liquid droplet speed detection apparatus 3 prior to the refresh when the head 1 reaches the non-print region.
- the liquid droplet a is first ejected from each nozzle 12 in the head 1, and the liquid droplet speed detection apparatus 3 detects an ejection speed of the liquid droplet a (S1).
- a detection result is transmitted to the CPU 101, and the CPU 101 determines whether the ejection speed of the liquid droplet a is lower than the threshold value and sedimentation of the solid particles is advancing from this result (S2) and then starts the refresh constituted of the micro-vibration operation and the ejection operation if the ejection speed was determined to be lower than the threshold value (S3).
- the ejection speed of the liquid droplet a is not lower than the threshold value, it is determined that sedimentation of the solid particles in the ink chamber 11 has not advanced and ejection is not required, and the refresh in the non-print region is not carried out. Therefore, the unnecessary consumption of the ink and the contamination of the periphery due to the satellite can be suppressed.
- the refresh after detecting the liquid droplet speed may be performed with respect to all the ink chambers 11 in the head 1 or individually performed with respect to the ink chamber 11 that has ejected the liquid droplet a whose ejection speed was lower than the threshold value when it was determined that the ejection speed of the liquid droplet a ejected from any nozzle 12 in the head 1 fell below the threshold value. In the latter case, the unnecessary consumption of the ink and the contamination of the periphery due to the satellite can be further suppressed.
- detecting an ejection speed of the liquid droplet in accordance with each head 1 and determining whether the refresh is to be performed enables carrying out an appropriate nozzle recovery operation in accordance with each head 1.
- the sedimentation of the solid particles in the ink in each ink chamber 11 advances when a period that no print data is provided continues for a long time even in the print region. If the plurality of heads 1 are provided in accordance with the respective colors, a head that ejects a white ink that is often used as a base may not be used for a long time. Therefore, it is also possible to estimate how the sedimentation of the solid particles in the ink has advanced near the nozzle 12 in the ink chamber 11 from a liquid droplet ejection pause period of the ink chamber 11 in the print region.
- the ejection operation is also preferable to select whether the ejection operation is to be performed in accordance with a pause period of ejection of the ink droplets from the nozzle 12 when the head 1 is present in the print region where printing is carried out.
- the unnecessary refresh can be prevented from being effected, and the wasteful consumption of the ink and the contamination of the periphery due to the satellite can be suppressed.
- FIG. 9 shows an example of a flow of selecting whether the refresh is to be performed in accordance with a liquid droplet ejection pause period.
- a liquid droplet ejection pause period of each nozzle 12 in the print region is first detected (S10).
- the ejection pause period of the liquid droplets from each nozzle 12 can be obtained by analyzing print data stored in the print data memory 102 in the CPU 101, for example. A detection result is transmitted to the CPU 101 .
- a threshold value indicative of an upper limit of the ejection pause period is preset in the CPU 101.
- the CPU 101 determines from the detection result whether the sedimentation of the solid particles has advanced so that the refresh should be carried out since the ejection pause period is long beyond the threshold value (S11). Additionally, if the ejection pause period was determined to exceed the threshold value, then the refresh constituted of the micro-vibration operation and the ejection operation is started (S12) . On the other hand, if the ejection pause period is lower than the threshold value, it is determined that the sedimentation of the solid particles in the ink chamber 11 has not advanced and the refresh is not required, and the refresh in the non-print region is not carried out. Therefore, the wasteful consumption of the ink and the contamination of the periphery due to the satellite can be suppressed.
- the refresh after detecting the ejection pause period may be performed with respect to all the ink chambers 11 in the head 1 or may be individually performed with respect to the ink chamber 11 having the ejection pause period exceeding the threshold value when the ejection pause period of any nozzle 12 in the head 1 was determined to exceed the threshold value. In the latter case, the wasteful consumption of the ink and the contamination of the periphery due to the satellite can be further suppressed.
- an appropriate nozzle recovery operation can be executed in accordance with each head 1 by detecting the ejection pause period in accordance with each head 1 and determining whether the refresh is to be performed.
- the CPU 101 controls the micro-vibration control unit 107 and the ejection control unit 108 to perform the refresh.
- the refresh involves ejection of the liquid droplets, the consumption of the ink increase. Therefore, it is also preferable to configure the liquid droplet ejection apparatus 100 to select one of a case where the refresh constituted of the micro-vibration operation and the ejection operation is performed and a case where the micro-vibration operation alone is performed without effecting liquid droplet ejecting operation by applying the plurality of micro-vibration pulses P2 to the drive electrodes on the partition walls 14 of the ink chambers 11.
- the refresh in this conformation is as described above, thereby omitting a description thereof.
- the micro-vibration pulse P2 shown in FIG. 4(b) alone in pulses generated by the drive pulse generation unit 106 is used.
- FIG. 10 shows examples of an application pattern of the micro-vibration pulse P2 when the micro-vibration operation alone is performed.
- a micro-vibration pulse applying operation for continuously applying the plurality of micro-vibration pulses P2 is continued during a period that the head 1 is present in the non-print region.
- the micro-vibration pulse applying operation is continued for a predetermined time alone, and the micro-vibration pulse applying operation that is one segment in this predetermined time is repeated more than once at intervals.
- a continuation time of the micro-vibration pulse applying operation as one segment may be uniformly set in one non-print region or may be non-uniformly set.
- selecting execution of the micro-vibration operation alone or execution of the refresh constituted of the micro-vibration operation and the ejection operation may be manually set by an operator using, e.g., a changeover switch in advance, but it is preferable to automatically select and execute the operation by the CPU 101 with a progression of sedimentation of the solid particles in each ink chamber 11 when the head 1 reaches the non-print region being used as a trigger.
- the progression of sedimentation of the solid particles in the ink in each ink chamber 11 can be detected by setting a predetermined threshold value and detecting an ejection speed of liquid droplets with the use of the liquid droplet detection apparatus 3 depicted in FIG. 7 .
- FIG. 11 shows an example of a flow that uses a detection result of the liquid droplet speed detection apparatus 3 as a trigger at the time of selecting the micro-vibration operation or the refresh to be performed.
- the liquid droplet speed detection apparatus 3 first ejects the liquid droplet a from each nozzle 12 in the head and detects an ejection speed (S20). A detection result is transmitted to the CPU 101.
- a first threshold value is a threshold value that is used for determining whether the micro-vibration operation is to be performed or whether nothing has to be performed.
- a second threshold value is a threshold value that is set to a value lower than the first threshold value, indicative of a state that sedimentation of the solid particles has advanced to some extent, and used for determining whether the micro-vibration operation alone is to be performed or whether the refresh is to be performed.
- the CPU 101 first compares a detection result of the liquid droplet speed detection apparatus 3 with the first threshold value and determines whether the detection result is lower than the first threshold value so that sedimentation of the solid particles has advanced and hence the micro-vibration operation should be performed (S21) .
- the detection result is not lower than the first threshold value, it is determined that sedimentation of the solid particles in the ink chambers 11 has not advanced and hence the nozzle recovery operation is not required, and the nozzle recovery operation is not carried out in the non-print region. Therefore, the wasteful consumption of the ink and the contamination of the periphery due to the satellite can be suppressed.
- the detection result is then compared with the second threshold value (S22) .
- the refresh constituted of the micro-vibration operation and the ejection operation is started (S23) .
- the micro-vibration operation alone is performed (S24).
- a detection result of the liquid droplet ejection pause period can be used as a trigger. That is, when the head 1 first reaches the non-print region, a liquid droplet ejection pause period of each nozzle 12 in the print region is first detected based on print data (S30). The detection result is transmitted to the CPU 101.
- the CPU 101 first compares the detection result of the ejection pause period with the first threshold value and determines whether the detection result exceeds the first threshold value and sedimentation of the solid particles has advanced so that the micro-vibration operation should be performed (S31) .
- the detection result is lower than the first threshold value, it is determined that sedimentation of the solid particles in each ink chamber 11 has not advanced so that the nozzle recovery operation does not have to be performed, and the nozzle recovery operation is not performed in the non-print region. Therefore, the wasteful consumption of the ink and the contamination of the periphery due to the satellite can be suppressed.
- the detection result is compared with the second threshold value set to a value higher than the first threshold value (S32). As a result, if the detection result was determined to likewise exceed the second threshold value, then the refresh constituted of the micro-vibration operation and the ejection operation is started (S33). Further, if it was determined that the detection result was yet to exceed the second threshold value, the solid particles are determined to settle out to some extent, but the refresh does not have to be carried out, and then the micro-vibration operation alone is carried out (S34). As a result, the same effect as that in case of detecting an ejection speed of the liquid droplets can be provided.
- the micro-vibration operation when the head 1 reaches the non-print region, the micro-vibration operation may be always carried out.
- one set value can suffice as a threshold value, and whether the micro-vibration operation alone is to be performed or whether the refresh constituted of the micro-vibration operation and the ejection operation is to be performed may be determined based on comparison with this threshold value.
- whether the micro-vibration operation alone is to be performed or whether the refresh is to be performed may be selected and executed in accordance with a preset sequence.
- a selection trigger may be set by the number of times that the head 1 reaches the non-print region
- the micro-vibration operation may be always performed every time the head 1 is present in the non-print region
- the refresh constituted of the micro-vibration operation and the ejection operation may be performed every time the head 1 reaches the non-print region for the third time.
- the selection trigger may be set by a time
- the micro-vibration operation may be performed in a regular situation
- the refresh constituted of the micro-vibration operation and the ejection operation alone may be effected at start of printing or every time a predetermined time passes after execution of the previous refresh.
- a sedimentation speed of the solid particles rises as specific gravity of the solid particles relative to the dispersion medium increases, and hence sedimentation is facilitated.
- specific gravity of the solid particles relative to the dispersion medium may differ in levels in some cases.
- types of the solid particles contained in the ink differ depending on types (colors) of the inks for the respective heads 1, and hence the specific gravity of the solid particles relative to the dispersion medium may differ in levels .
- the micro-vibration pulse P2 it is preferable to raise an application frequency as the specific gravity increases in accordance with a level of the specific gravity of the solid particles relative to the dispersion medium.
- the application frequency of the micro-vibration pulse P2 is raised as the specific gravity increases, the ink in each ink chamber 11 can be efficiently micro-vibrated, and dispersion of the solid particles can be effectively facilitated.
- a level of the specific gravity of the solid particles relative to the dispersion medium can be manually set by, e.g., providing a non-illustrated input switch to the liquid droplet ejection apparatus 100 and performing an input operation by an operator in accordance with a type of the ink at the time of setting an ink tank or an ink cartridge storing the ink to the apparatus, or it may be automatically set by recognizing identifying information of the type of the ink provided on the ink tank or the ink cartridge with the use of non-illustrated recognizing means provided to the liquid droplet ejection apparatus 100.
- the input result or the identification result is transmitted to the CPU 101, and the micro-vibration control unit 107 controls the micro-vibration operation based on the input result or the identification result.
- FIG. 13 shows an example of a table that is preferably used at the time of adjusting an application frequency in accordance with a level of the specific gravity of the solid particles relative to the dispersion medium.
- a relationship between a level of the specific gravity of the solid particles relative to the dispersion medium (a ratio of a specific gravity difference of the solid particles relative to specific gravity of the dispersion medium) and an application frequency of the micro-vibration pulse, and it is stored in, e.g., the CPU 101.
- a sedimentation speed of the solid particles is relatively slow, and hence the application frequency is reduced, and the application frequency is raised as the level of the specific gravity increases.
- the ink in the common ink chamber 13 in the head 1 can be circulated between the common ink chamber 13 and the ink tank 4 storing the ink.
- a supply pipe 41 and a return pipe 42 are connected between the common ink chamber 13 of the head 1 and the ink tank 4, a circulation pump 43 is provided to the return pipe 42, and the supply pipe 41, the return pipe 42, and the circulation pump 43 constitute circulating means.
- the ink is circulated between the ink tank 4 and the common ink chamber 13 of the head 1 by drive of the circulation pump 43.
- the ink in which the solid particles having the uniform concentration can be supplied to the ink chambers 11.
- sedimentation of the solid particles in the ink in the ink chambers 11 can be further suppressed, and an ink replacement effect based on the refresh can be improved.
- the ink in each ink chamber 11 can be replaced with an ink having uniform concentration at the time of refresh, and hence it is preferable to carry out the ink circulating operation at least during a period that the refresh constituted of the micro-vibration operation and the ejection operation is performed.
- nozzle maintenance means that performs maintenance for recovery of the nozzles 12
- a wiping operation for wiping off stains on each nozzle surface with the use of a blade
- a removing operation for pressing a water-absorptive member such as cloth against each nozzle surface and removing the ink, and others when the head 1 is present in the non-print region
- any one or more of these means may be provided in the liquid droplet ejection apparatus 100 and carried out.
- the micro-vibration operation alone is performed as the nozzle recovery operation, since a meniscus in the nozzle 12 vibrates by micro-vibration, and hence the meniscus may be destroyed at the time of the wiping operation or the removing operation.
- the liquid droplet ejection apparatus 100 the line type liquid droplet ejection apparatus that performs printing on a surface of a recording medium in one pass has been described, but the liquid droplet ejection apparatus may be a scan type liquid droplet ejection apparatus that performs printing by reciprocating the head 1 in a main scan direction.
- FIG. 15 shows an example of such a scan type liquid droplet ejection apparatus.
- a recording medium W is sandwiched between a pair of conveyance rollers 201 and conveyed in a direction indicated by an arrow (a sub-scan direction) by a conveyance roller 203 that is driven to rotate by a conveyance motor 202 .
- a head 1 is provided between the conveyance roller 203 and the pair of conveyance rollers 201 so as to face a surface of the recording medium W.
- the head 1 is arranged and mounted on a carriage 204 in such a manner that a nozzle surface side faces the recording medium W.
- the carriage 204 is provided to enable its reciprocating motion along a left-and-right direction in the drawing (the main scan direction) substantially orthogonal to a conveyance direction (the sub-scan direction) of the recording medium W by non-illustrated driving means along guide rails 205 installed along a width direction of the recording medium W.
- the head 1 horizontally scans and moves on the surface of the recording medium W with movement of the carriage 204 in the main scan direction, and ejecting the liquid droplets from the nozzles 12 in this scanning and moving process enables performing desired printing.
- both lateral sides of the recording medium W are non-print regions in which no print data is provided and printing based on the print data is not performed.
- ink receivers 206 are arranged at positions facing the nozzle surfaces of the head 1. Therefore, at the time of performing refresh when the head 1 reaches the non-print region, the liquid droplets are ejected toward the ink receivers 206.
- this apparatus can be arranged in each of the non-print regions on both sides of the recording medium W.
- each partition wall 14 between the neighboring ink chambers 11 and 11 is formed of a piezoelectric partition wall 14 and which ejects the ink in the ink chambers 11 as liquid droplets from the nozzles 12 by a deforming operation of each partition wall 14 has been described as the example, but a specific structure of the energy giving means for giving energy to the ink in the ink chamber is out of the question.
- a heater may be provided in the ink chambers as the energy giving means, air bubbles may be generated in the ink by energizing the heater, and the liquid droplets may be ejected from the nozzles by a breaking function of the air bubbles, or one wall surface of the ink chamber may be formed of a diaphragm as the energy giving means, this diaphragm may be vibrated by a deforming operation of the piezoelectric element, the ink in the ink chamber may be given energy, and the liquid droplets may be ejected from the nozzles.
- the head 1 is not restricted to a head in which nozzle surfaces are arranged to be vertically downward directed, and nozzle surfaces may be arranged in a horizontal direction or an oblique direction.
- a scan type liquid droplet ejection apparatus having ink receivers arranged in non-print regions on both lateral sides of a recording medium was used, predetermined printing was performed in a print region of the recording medium from a head using a UV ink containing a dispersion medium and a titanium oxide in which solid particles have specific gravity higher than that of the dispersion medium (a specific gravity difference between the dispersion medium and the solid particles: 0.25, the content of a material having a steam pressure higher than that of wafer at an ordinary temperature: 5%), a micro-vibration pulse having a frequency that is a half of a liquid droplet ejection frequency at the time of printing was applied every time the head reached the non-print region in order to turn back at an end portion in a main scan direction, and then liquid droplets having the same frequency as the ejection frequency were ejected into each ink receiver.
- the continuous operation was performed under the same conditions as those in Example 1 except that the micro-vibration pulse was not applied in each non-print region and the ejection operation alone was performed.
- the continuous operation was performed under the same conditions as those in Example 1 except that the micro-vibration pulse alone was applied in each non-print region and the ejection operation was not performed.
- a line type liquid droplet ejection apparatus that performs printing on a surface of each ceramic tile conveyed by a conveyance belt in one pass from a head was used, and predetermined printing was performed in a print region on the ceramic tile surface from the head using an oil ink containing a dispersion medium and pigment particles of yellow as solid particles (a specific gravity difference between the dispersion medium and the solid particles: 0.30, the content of a material having a steam pressure higher than that of water at an ordinary temperature: 3%).
- the micro-vibration pulse having the same frequency as a liquid droplet ejection frequency at the time of printing was applied, and then liquid droplets having the same frequency as the ejection frequency were ejected into each ink receiver.
- the continuous operation was performed under the same conditions as those in Example 2 except that the ejection operation alone was performed without applying a micro-vibration pulse in each non-print region.
Landscapes
- Ink Jet (AREA)
- Particle Formation And Scattering Control In Inkjet Printers (AREA)
Description
- The present invention relates to a liquid droplet ejection apparatus and a method for recovering a nozzle of the liquid droplet ejection apparatus, and more particularly to a liquid droplet ejection apparatus that can suppress sedimentation of solid particles contained in an ink and stably eject liquid droplets for a long time and a method for recovering a nozzle of the liquid droplet ejection apparatus.
- A liquid droplet ejection apparatus that performs printing by ejecting liquid droplets from a head is generally used for various industrial purposes as an inkjet printer. Applications of this industrial inkjet increases year by year, and the inkjet printer is used for not only performing printing on paper sheets, fabric, plastic sheets, and others but also performing printing a design on a surface of a ceramic tile in recent years. Accordingly, performance that enables stably ejecting various kinds of inks for a long time has been demanded with respect to the liquid droplet ejection apparatus.
- However, in case of performing printing by using as an ink a ceramic ink containing solid particles of ceramics or a white ink containing solid particles of a titanium oxide or the like as a pigment and ejecting liquid droplets from a head, sedimentation of the solid particles in the ink occurs in an ink chamber when print data is not present or the head is present in a non-print region where the head does not perform printing. That is because these solid particles have specific gravity higher than that of dispersion medium in the ink. When the sedimentation of the solid particles occurs in the ink chamber, density of the solid particle near the nozzle rises, and nozzle clogging may be possibly caused. Further, when the solid particles having the high density are solidified, ejection cannot be performed on a permanent basis.
- Even if the nozzle is arranged sideways, since a concentration distribution is produced in the ink in the ink chamber due to the sedimentation of the solid particles, the solid particles in liquid droplets do not have adequate concentration even though the liquid droplets were successfully ejected, and irregularity of an ejection rate or non-uniformity of images may occur.
- According to the prior art, to reduce sedimentation of solid matters such as a pigment in an ink, a technology that circulates the ink by using a pressure difference between a head and an ink tank has been suggested (Patent Document 1). However, the ink on the ink side that is circulated by this technology is an ink in a common ink chamber that exclusively supplies the ink to respective ink chambers in common, and the ink supplied to the respective ink chamber cannot be circulated. Therefore, at a print pause time, the sedimentation of the solid particles that occurs in the ink chambers cannot be suppressed.
- As a countermeasure for nozzle clogging during the printing pause, there has been known a technology that applies a preliminary waveform to each ink chamber to vibrate a meniscus immediately before restarting ejection and allows the ink in the ink chambers to flow (Patent Document 2) . However, this technology eliminates the nozzle clogging by an increase in viscosity based on evaporation of a volatile component in the ink. The flow of the ink caused by such meniscus vibration is very small, and hence the increase in viscosity is effective for elimination of the nozzle clogging, but just finely vibrating the meniscus cannot sufficiently eliminate a sedimentation state of the solid particles that has advanced to some extent in the ink chambers.
- Furthermore, there has been also known detecting viscosity of an ink and adjusting intensity of micro-vibration and an amount of liquid droplets at the time of discharging an ink (Patent Document 3). However, this technology prevents nozzle clogging caused due to evaporation of a liquid and an increase in viscosity of the ink, and does not solve a problem caused by the sedimentation of the solid particles contained in the ink.
-
- Patent Document 1:
JP-A-2011-506152 - Patent Document 2:
JP-A-2000-203020 - Patent Document 3:
JP-A-2012-96423 -
US 2009/160887 A1 discloses a liquid droplet ejection head comprising an ejector, a liquid viscosity-increase prevention structure and a liquid viscosity-increase prevention controller. The ejector includes a nozzle for ejecting a liquid droplet, a pressure chamber communicating with the nozzle through a communication path, and an actuator for applying pressure to a liquid in the pressure chamber. The liquid viscosity-increase prevention structure prevents an increase of viscosity of the liquid in the ejector. The liquid viscosity-increase prevention controller changes the operation frequency of the liquid viscosity-increase prevention structure between when the liquid droplet is ejected from the nozzle and when ejection of the liquid droplet is paused and no liquid droplet is being ejected from the nozzle. -
US 2002/171704 A1 discloses a liquid jetting apparatus including a head member having a nozzle, a supporting member that can support a medium, a scanning mechanism that can cause the head member to relatively move with respect to the medium, and a liquid jetting unit that can jet liquid from the nozzle. An area storing unit stores a relative area to which liquid can be jetted from the nozzle while the head member is caused to relatively move by the scanning mechanism. An out-of-jetting micro-vibrating-area setting unit can set out-of-jetting micro-vibrating areas before and after the relative area. A micro-vibrating unit causes liquid in the nozzle to minutely vibrate. An out-of-jetting micro-vibrating controlling unit causes the micro-vibrating unit to operate when the head member is located in the out-of-jetting micro-vibrating areas, while the head member is caused to relatively move by the scanning mechanism, based on the out-of-jetting micro-vibrating areas and head-position information. -
EP 2 127 882 A1 - Therefore, it is an object of the present invention to provide a liquid droplet ejection apparatus that can effectively eliminate the sedimentation of solid particles contained in an ink and stably eject liquid droplets for a long time.
- Further, it is another object of the present invention to provide a method for recovering a nozzle of a liquid droplet ejection apparatus that can effectively eliminate the sedimentation of solid particles contained in an ink and stably eject liquid droplets for a long time.
- Furthermore, other objects of the present invention will become obvious from the following description.
- Accordingly, there is provided a liquid droplet ejection apparatus as set out in
independent claim 1 and a method for recovering a nozzle of a liquid droplet ejection apparatus as set out in independent claim 10. Advantageous developments are defined in the dependent claims. - According to the present invention, it is possible to provide the liquid droplet ejection apparatus that can effectively eliminate the sedimentation of solid particles contained in an ink and stably eject liquid droplets for a long time.
- Moreover, according to the present invention, it is possible to provide the method for recovering
a nozzle of a liquid droplet ejection apparatus that can effectively eliminate the sedimentation of solid particles contained in an ink and stably eject liquid droplets for a long time. -
-
FIG. 1 is a perspective view showing an example of a line type liquid droplet ejection apparatus; -
FIG. 2 is a cross-sectional view of a head in the liquid droplet ejection apparatus; -
FIG. 3 is a block diagram showing an outline configuration of the liquid droplet ejection apparatus; -
FIG. 4(a) is a view showing an example of an ejection pulse andFIG. 4 (b) is a view showing an example of a micro-vibration pulse; -
FIG. 5 is a view for explaining a capacity of an ink chamber; -
FIG. 6 is a view showing an application pattern of the micro-vibration pulse and the ejection pulse at the time of refresh; -
FIG. 7 is a view for explaining an example of detecting means for detecting a sedimentation state of solid particles; -
FIG. 8 is a view showing an example of a flow for detecting a speed of liquid droplets by a liquid droplet speed detection apparatus prior to refresh; -
FIG. 9 is a view showing an example of a flow for detecting an ejection pause period of liquid droplets prior to refresh; -
FIGS. 10(a) and (b) are views showing examples of an application pattern of the micro-vibration pulse in case of performing a micro-vibration operation alone, respectively; -
FIG. 11 is a view showing an example of a flow of selecting the micro-vibration operation and the refresh by using a detection result of the liquid droplet speed detection apparatus as a trigger; -
FIG. 12 is a view showing an example of a flow for selecting the micro-vibration operation and the refresh by using a detection result of a liquid droplet ejection pause period as a trigger; -
FIG. 13 is a view showing an example of a table specifying a relationship between a ratio of specific gravity difference of solid particles relative to specific gravity of a dispersion medium and a micro-vibration pulse applying frequency; -
FIG. 14 is a view for explaining an example of a structure that enables an ink to circulate; and -
FIG. 15 is an exterior view showing an example of a scan type liquid droplet ejection apparatus. - An embodiment according to the present invention will now be described hereinafter in detail.
-
FIG. 1 is a perspective view showing an example of a liquid droplet ejection apparatus, andFIG. 2 is a cross-sectional view showing an example of a head. In the drawings,reference numeral 100 denotes a liquid droplet ejection apparatus; 1, a head; and 2, a conveyance belt. - In the liquid
droplet ejection apparatus 100, ceramic tiles C as recording mediums are mounted at intervals on aconveyance surface 2a of aconveyance belt 2 that is driven to rotate in one direction, and they are conveyed in an arrow direction in the drawing. In thehead 1, a plurality ofnozzles 12 are aligned along an X direction in the drawing parallel to a width direction of theconveyance belt 2, and nozzle surfaces are arranged to be vertically downward directed so that they face theconveyance surface 2a. Further, a ceramic ink containing, e.g., ceramic particles having specific gravity higher than that of dispersion medium is ejected as solid particles from therespective nozzles 12 to a print region on a front surface of each ceramic tile C that is conveyed at a fixed speed by theconveyance belt 2 based on print data, thereby forming a predetermined image. - In the
head 1, as shown inFIG. 2 , a plurality ofink chambers 11 are aligned along the X direction. Here, although an example where 20ink chambers 11 are aligned in line along the X direction is shown, the number of theink chambers 11 and the number of columns are out of the question. In thishead 1, all theink chambers 11 are ink chambers that can eject liquid droplets from thenozzles 12 provided in accordance with therespective ink chambers 11 when the ink in acommon ink chamber 13 provided to communicate with therespective ink chambers 11 is supplied thereto. - In this
head 1, eachpartition wall 14 that separates the neighboringink chambers partition walls 14 facing the inside of theink chambers 11. In thehead 1, when a drive pulse of a predetermined voltage is applied to each drive electrode from a later-described head driver, eachpartition wall 14 deforms, and a capacity of eachink chamber 11 changes. When this change in capacity increases to eject the ink in eachink chamber 11 from eachnozzle 12 formed on anozzle plate 15, ejection energy is given to the ink in eachink chamber 11, and liquid droplets are ejected from eachnozzle 12. It is to be noted that, in thishead 1, thepartition walls 14 having the drive electrodes formed thereon constitute energy giving means for giving the ink in theink chambers 11 the energy. - Here, the ink to be used in the present invention contains dispersion medium as well as solid particles having higher specific gravity than that of the dispersion medium. The dispersion medium is out of the question. As the solid particles, there are ceramic particles in the ceramic ink, pigment particles of a titanium oxide, and others.
- When a specific gravity difference of the solid particles relative to the dispersion medium is high, a sedimentation speed increases, the solid particles are apt to settle out in the ink chambers, and a problem of the present invention becomes prominent. It is preferable for the specific gravity difference between the dispersion medium and the solid particles in the present invention to be 0.2 or more since an effect of the present invention can be considerably provided, which is preferable.
- In the present invention, the ink that does not volatilize by drying at an ordinary temperature under an ordinary pressure is used. Here, "the ink that does not volatilize" means an ink in which the content of a material, whose steam pressure at an ordinary temperature is higher than that of water, is 10% or less or preferably 5% or less. Such an ink does not have a problem of an increase in viscosity due to evaporation of a volatile component that can be observed when a volatile ink such as an aqueous ink is used at the time of use. As such an ink, for example, there are a UV ink, an oil ink, and others.
-
FIG. 3 is a block diagram showing an outline configuration of the inside of the liquiddroplet ejection apparatus 100. -
Reference numeral 101 denotes a CPU that controls the entire liquiddroplet ejection apparatus 100; 102, a print data memory that stores print data to be formed in a print region on the surface of each ceramic tile C; 103, an encoder that detects a moving length of theconveyance belt 2; 104, a belt conveyance motor that drives theconveyance belt 2 to rotate; 105, a head driver that gives a pulse to the drive electrodes of thehead 1 to deform thepartition walls 14; 106, a drive pulse generation unit that is provided in thehead driver 105 and generates a drive pulse as a drive signal to be supplied to thehead 1; 107, a micro-vibration control unit that is provided in theCPU 101 and controls a micro-vibration operation for micro-vibrating the ink in theink chambers 11; and 108, an ejection control unit that is provided in theCPU 101 and controls an ejection operation of ejecting the ink in theink chambers 11. - When the
head 1 is present in a non-print region where printing based on print data is not performed, themicro-vibration control unit 107 controls drive of thehead 1 through thehead driver 105 so as to perform a micro-vibration operation for micro-vibrating the ink in theink chambers 11 and providing the solid particles with kinetic energy to facilitate dispersion. In the present invention, thismicro-vibration control unit 107 constitutes micro-vibrating means. - When the
head 1 is present in a non-print region where printing based on print data is not performed, theejection control unit 108 controls drive of thehead 1 through thehead driver 105 so as to perform an ejection operation for forcibly ejecting the ink in theink chambers 11 and replacing the ink in theink chambers 11 with a new ink. In the present invention, themicro-vibration control unit 107 and theejection control unit 108 constitute refreshing means. - A pulse generated by the drive
pulse generating unit 106 includes an ejection pulse P1 for ejecting liquid droplets from thenozzles 12 like an example shown inFIG. 4(a) and a micro-vibration pulse P2 for micro-vibrating the ink in theink chambers 11 so as not to eject liquid droplets from thenozzles 12 like an example shown inFIG. 4(b) . The drivepulse generating unit 106 selects one of these drive pulses in accordance with an instruction from theCPU 101 and applies the drive pulse to the drive electrodes formed on thepartition walls 104 of thehead 1. - In case of ejecting the ink containing the solid particles having higher specific gravity than that of the dispersion medium from the
nozzles 12 in accordance with print data, sedimentation of the solid particles may possibly cause an ejection failure such as nozzle clogging if a period during which ejection from thenozzle 12 pauses when thehead 1 is in the print region or a small period during which ejection pauses when thehead 1 is in the non-print region has been passed. Thus, in the present invention, when thehead 1 is in this non-print region, refresh for ejecting liquid droplets from therespective nozzles 12 to eject the ink is performed under control of theCPU 101, thereby stabilizing the ejection. - It is to be noted that, in the present invention, as different from the print region where the liquid droplets are ejected from the
nozzles 12 based on print data and printing is carried out with respect to a recording medium, the non-print region is a region which deviates from the recording medium has no print data and in which printing based on this print data is not performed. As seen from thehead 1, print regions and non-print regions alternately fed. In this liquiddroplet ejection apparatus 100, a space between the ceramic tiles C, C continuously mounted on theconveyance surface 2a at an interval is the non-print region where printing based on print data is not carried out. Arrival of thehead 1 at the non-print region is detected by a moving length of theconveyance belt 2 detected by theencoder 103. - The refresh of the
head 1 executed by theCPU 101 is performed by the micro-vibration operation under control of themicro-vibration control unit 107 and the ejection operation performed after this micro-vibration operation under control of theejection control unit 108. That is, when thehead 1 is present in the non-print region during a period from passage of one ceramic tile C through a position immediately below thehead 1 to arrival of the subsequent ceramic tile C at the position immediately below thehead 1, the refresh is constituted of the micro-vibration operation for applying the plurality of micro-vibration pulses P2 to the drive electrodes of thepartition walls 14 and micro-vibrating the ink in theink chambers 11 so as not to eject the liquid droplets from thenozzles 12 under control of themicro-vibration control unit 107 and the ejection operation for applying the plurality of ejection pulses P1 to the drive electrodes of thepartition walls 14 after effecting the micro-vibration operation and ejects the liquid droplets from thenozzles 12 to provide a liquid droplet amount that is equal to or above the capacity of theink chamber 11 under control of theejection control unit 108. - The capacity of the
ink chamber 11 means a capacity of an ink channel between a boundary relative to thecommon ink chamber 13 and an end opening portion of eachnozzle 12. Therefore, this capacity does not include a capacity in thecommon ink chamber 13. In thehead 1 according to this embodiment, as shown inFIG. 5 , this capacity is a capacity of a space with a distance D that serves as an ink channel from anopening portion 11a of theink chamber 11 that is a boundary relative to thecommon ink chamber 13 between both thepartition walls 14 defining eachink chamber 11 to anend opening portion 12a of thenozzle 12 that is opened in a surface (a nozzle surface) of thenozzle plate 15. - Since a liquid droplet volume of one droplet ejected by one ejection pulse P1 is known in advance, the liquid droplet amount that is equal to or greater than the capacity of the
ink chamber 11 can be defined by the total number of times of applying the ejection pulses P1. - When the refresh is performed while the
head 1 is present in the non-print region, a total amount of the ink stored in theink chambers 11 is forcibly ejected from thenozzles 12. Therefore, even if sedimentation of the solid particles advances in theink chambers 11, all of the ink in theink chambers 11 is replaced with an ink newly supplied from thecommon ink chamber 13, and the solid particles do not keep settling out in theink chambers 11. As a result, concentration of the solid particles in the ink in theink chambers 11 can be maintained constant, occurrence of nozzle clogging is suppressed, and stable ejection can be performed for a long time. - Further, in the refresh, not only simple ejection of the liquid droplets is performed, but also the ink in the
ink chambers 11 is micro-vibrated before ejecting the liquid droplets, the solid particles is provided with kinetic energy, and hence the settled and aggregated solid particles in the ink before ejection are apt to be dispersed, thereby smoothly discharging the ink from thenozzles 12 by the energy given at the time of subsequent ejection. Therefore, the settled solid particles do not remain in theink chambers 11, and a total amount of the ink in theink chambers 11 can be efficiently replaced. When ejection of the liquid droplets alone is performed without micro-vibrating the ink in a state that the sedimentation of the solid particles has advanced, the solid particles settled out in theink chambers 11 cannot be smoothly discharged from thenozzles 12, and the solid particles might remain, or nozzle clogging might possibly occur by the aggregated solid particles. -
FIG. 6 shows an example of an application pattern of the ejection pulse P1 and the micro-vibration pulse P2 at the time of performing the refresh. Here, when thehead 1 enters the non-print region, a micro-vibration pulse applying operation for continuously applying the plurality of micro-vibration pulses P2 is first continued for a predetermined time t1, and then an ejection pulse applying operation for continuously applying the plurality of ejection pulses P1 is continued for a predetermined time t2. Furthermore, the micro-vibration pulse applying operation of the time t1 and the ejection pulse applying operation of the time t2 are continuously alternately repeated three times. - To equalize a liquid droplet amount ejected from the
nozzles 12 with an amount that is equal to or higher than the capacity of each ink chamber in one non-print region, as shown inFIG. 6 , in case of performing the ejection pulse applying operation in one segment that is the time t2 more than once in one non-print region, the liquid droplets can be ejected so that a total liquid droplet amount of the liquid droplets ejected by the ejection pulse applying operation performed more than once can be a liquid droplet amount equal to or above the capacity of theink chamber 11. According to this configuration, since the ink containing the solid particles settled out in eachink chamber 11 is ejected little by little while being dispersed little by little by provision of the micro-vibration, a total amount of the ink in eachink chamber 11 can be effectively replaced even if sedimentation of the solid particles advances and the ink is hard to be discharged from thenozzles 12. - Further, the liquid droplets can be ejected so as to provide an amount of liquid droplets that is equal to or greater than the capacity of each
ink chamber 11 in accordance with each single ejection pulse applying operation in one non-print region. In this case, a total amount of the ink is replaced more than once in one non-print region. According to this operation, since a flowing amount of the ink around theink chambers 11 including thecommon ink chamber 13 in thehead 1 increases, an effect for enabling supply of the ink in which the solid particles are uniformly dispersed into theink chambers 11 can be improved. - The number of times of occurrence of the micro-vibration pulse applying operation of the time t1 and the ejection pulse applying operation of the time t2 in one non-print region is out of the question as long as the micro-vibration pulse applying operation is carried out immediately before the ejection pulse applying operation. Furthermore, in
FIG. 6 , three sets of the time t1 of the micro-vibration pulse P2 are all uniform and three sets of the time t2 of the respective ejection pulse P1 are also uniform, but the time t1 and the time t2 may be set to be non-uniform in each applying operation. That is, the number of times of applying the ejection pulse P1 or the micro-vibration pulse P2 in each applying operation may differ in accordance with each applying operation. - Although the refresh that the micro-vibration operation and the ejection operation are carried out can be effected every time the
head 1 reaches the non-print region, there might be a case that sedimentation of the solid particles in the ink in theink chambers 11 does not substantially advance like a situation where a large amount of liquid droplets are continuously ejected from thenozzle 12 in the print region or where a specific gravity difference of the dispersion medium and the solid particles is relatively small depending on a type of ink. In such a case, when the ink ejection operation is carried out every time thehead 1 reaches the non-print region, the ink is wastefully consumed. Moreover, since the liquid droplets containing the solid particles is apt to produce a satellite, there is concern that the generated satellite turns to mist and scatters at the time of ejection, leading to contamination of the periphery. To suppress the waste of the ink or the contamination of the periphery due to the satellite, it is desirable to restrict the liquid droplets that are ejected by the ejection operation to the minimum requirement. - Therefore, it is also preferable for the
CPU 101 to select whether the refresh is to be carried out in accordance with a sedimentation state, i.e., a state of progress of sedimentation of the solid particles in the ink in theink chambers 11 when thehead 1 is present in the non-print region. As a result, the unnecessary ejection operation can be prevented from being performed, and the wasteful consumption of the ink and the contamination of the periphery due to the satellite can be suppressed. - In general, an ejection speed of the liquid droplets ejected from the
nozzles 12 is lowered as a quantity of the solid particles contained in the liquid droplets increases. Therefore, it is possible to estimate of a state of progress of sedimentation of the solid particles in the ink near thenozzles 12 in theink chamber 11. -
FIG. 7 shows a liquid dropletspeed detection apparatus 3 which is an example of detecting means for detecting an ejection speed of the liquid droplets. This liquid dropletspeed detection apparatus 3 is configured to operate in response to an instruction from theCPU 101 and transmit a result to theCPU 101 as shown inFIG. 3 . - The liquid droplet
speed detection apparatus 3 has alight projection unit 31 formed of an LED or a laser that emits detection light L and alight receiving unit 32 formed of a photosensor or the like that receives this detection light L, and the liquid dropletspeed detection apparatus 3 is arranged near a position immediately belownozzles 12 in such a manner that an optical axis of the detection light L becomes parallel to the X direction as an alignment direction of thenozzles 12 and also becomes parallel to the nozzle surface. As a result, the liquid droplet ejected from eachnozzle 12 crosses the detection light L, and a shade when the liquid droplet a passes is captured by thelight receiving unit 32. Additionally, when the ejection pulse P is applied to any one ofink chambers 11 and the liquid droplet a is ejected from thenozzle 12, the liquid dropletspeed detection apparatus 3 calculates an ejection speed of the liquid droplet a from a time required to capture a shade of the liquid droplet a from application of the ejection pulse P1 and a distance to the optical axis of the detection light L from thenozzle 12. - A threshold value indicative of a lower limit of a preferred ejection speed of the liquid droplet a is preset to one of the
CPU 101 and the liquid dropletspeed detection apparatus 3. When the ejection speed of the liquid droplet a detected in a case where thehead 1 is present in the non-print region falls below this threshold value, sedimentation of the solid particles in the ink in the correspondingink chamber 11 is progressing, and it is possible to determine that the refresh should be carried out. -
FIG. 8 shows an example of a flow for detecting a speed of the liquid droplet a by the liquid dropletspeed detection apparatus 3 prior to the refresh when thehead 1 reaches the non-print region. When thehead 1 reaches the non-print region, the liquid droplet a is first ejected from eachnozzle 12 in thehead 1, and the liquid dropletspeed detection apparatus 3 detects an ejection speed of the liquid droplet a (S1). A detection result is transmitted to theCPU 101, and theCPU 101 determines whether the ejection speed of the liquid droplet a is lower than the threshold value and sedimentation of the solid particles is advancing from this result (S2) and then starts the refresh constituted of the micro-vibration operation and the ejection operation if the ejection speed was determined to be lower than the threshold value (S3). On the other hand, when the ejection speed of the liquid droplet a is not lower than the threshold value, it is determined that sedimentation of the solid particles in theink chamber 11 has not advanced and ejection is not required, and the refresh in the non-print region is not carried out. Therefore, the unnecessary consumption of the ink and the contamination of the periphery due to the satellite can be suppressed. - The refresh after detecting the liquid droplet speed may be performed with respect to all the
ink chambers 11 in thehead 1 or individually performed with respect to theink chamber 11 that has ejected the liquid droplet a whose ejection speed was lower than the threshold value when it was determined that the ejection speed of the liquid droplet a ejected from anynozzle 12 in thehead 1 fell below the threshold value. In the latter case, the unnecessary consumption of the ink and the contamination of the periphery due to the satellite can be further suppressed. - Moreover, if the plurality of
heads 1 are provided in accordance with respective colors, detecting an ejection speed of the liquid droplet in accordance with eachhead 1 and determining whether the refresh is to be performed enables carrying out an appropriate nozzle recovery operation in accordance with eachhead 1. - The sedimentation of the solid particles in the ink in each
ink chamber 11 advances when a period that no print data is provided continues for a long time even in the print region. If the plurality ofheads 1 are provided in accordance with the respective colors, a head that ejects a white ink that is often used as a base may not be used for a long time. Therefore, it is also possible to estimate how the sedimentation of the solid particles in the ink has advanced near thenozzle 12 in theink chamber 11 from a liquid droplet ejection pause period of theink chamber 11 in the print region. Therefore, it is also preferable to select whether the ejection operation is to be performed in accordance with a pause period of ejection of the ink droplets from thenozzle 12 when thehead 1 is present in the print region where printing is carried out. As a result, the unnecessary refresh can be prevented from being effected, and the wasteful consumption of the ink and the contamination of the periphery due to the satellite can be suppressed. -
FIG. 9 shows an example of a flow of selecting whether the refresh is to be performed in accordance with a liquid droplet ejection pause period. When thehead 1 reaches the non-print region, a liquid droplet ejection pause period of eachnozzle 12 in the print region is first detected (S10). The ejection pause period of the liquid droplets from eachnozzle 12 can be obtained by analyzing print data stored in theprint data memory 102 in theCPU 101, for example. A detection result is transmitted to theCPU 101 . - A threshold value indicative of an upper limit of the ejection pause period is preset in the
CPU 101. TheCPU 101 determines from the detection result whether the sedimentation of the solid particles has advanced so that the refresh should be carried out since the ejection pause period is long beyond the threshold value (S11). Additionally, if the ejection pause period was determined to exceed the threshold value, then the refresh constituted of the micro-vibration operation and the ejection operation is started (S12) . On the other hand, if the ejection pause period is lower than the threshold value, it is determined that the sedimentation of the solid particles in theink chamber 11 has not advanced and the refresh is not required, and the refresh in the non-print region is not carried out. Therefore, the wasteful consumption of the ink and the contamination of the periphery due to the satellite can be suppressed. - The refresh after detecting the ejection pause period may be performed with respect to all the
ink chambers 11 in thehead 1 or may be individually performed with respect to theink chamber 11 having the ejection pause period exceeding the threshold value when the ejection pause period of anynozzle 12 in thehead 1 was determined to exceed the threshold value. In the latter case, the wasteful consumption of the ink and the contamination of the periphery due to the satellite can be further suppressed. - Further, when the plurality of
heads 1 are provided in accordance with the respective colors, an appropriate nozzle recovery operation can be executed in accordance with eachhead 1 by detecting the ejection pause period in accordance with eachhead 1 and determining whether the refresh is to be performed. - In the above-described conformation, when the
head 1 is present in the non-print region, theCPU 101 controls themicro-vibration control unit 107 and theejection control unit 108 to perform the refresh. However, since the refresh involves ejection of the liquid droplets, the consumption of the ink increase. Therefore, it is also preferable to configure the liquiddroplet ejection apparatus 100 to select one of a case where the refresh constituted of the micro-vibration operation and the ejection operation is performed and a case where the micro-vibration operation alone is performed without effecting liquid droplet ejecting operation by applying the plurality of micro-vibration pulses P2 to the drive electrodes on thepartition walls 14 of theink chambers 11. - The refresh in this conformation is as described above, thereby omitting a description thereof. On the other hand, in case of selecting and executing the micro-vibration operation alone, as a pulse applied to the drive electrodes formed on the
partition walls 14 of thehead 1 from thehead driver 105, the micro-vibration pulse P2 shown inFIG. 4(b) alone in pulses generated by the drivepulse generation unit 106 is used. -
FIG. 10 shows examples of an application pattern of the micro-vibration pulse P2 when the micro-vibration operation alone is performed. In the application pattern shown in (a), a micro-vibration pulse applying operation for continuously applying the plurality of micro-vibration pulses P2 is continued during a period that thehead 1 is present in the non-print region. On the other hand, in the application pattern shown in (b), the micro-vibration pulse applying operation is continued for a predetermined time alone, and the micro-vibration pulse applying operation that is one segment in this predetermined time is repeated more than once at intervals. A continuation time of the micro-vibration pulse applying operation as one segment may be uniformly set in one non-print region or may be non-uniformly set. - When the
head 1 is present in the non-print region, selecting execution of the micro-vibration operation alone or execution of the refresh constituted of the micro-vibration operation and the ejection operation may be manually set by an operator using, e.g., a changeover switch in advance, but it is preferable to automatically select and execute the operation by theCPU 101 with a progression of sedimentation of the solid particles in eachink chamber 11 when thehead 1 reaches the non-print region being used as a trigger. The progression of sedimentation of the solid particles in the ink in eachink chamber 11 can be detected by setting a predetermined threshold value and detecting an ejection speed of liquid droplets with the use of the liquiddroplet detection apparatus 3 depicted inFIG. 7 . -
FIG. 11 shows an example of a flow that uses a detection result of the liquid dropletspeed detection apparatus 3 as a trigger at the time of selecting the micro-vibration operation or the refresh to be performed. When thehead 1 reaches the non-print region, the liquid dropletspeed detection apparatus 3 first ejects the liquid droplet a from eachnozzle 12 in the head and detects an ejection speed (S20). A detection result is transmitted to theCPU 101. - Two threshold values of the ejection speed corresponding to a progression of sedimentation of the solid particles are set in the
CPU 101 in advance. A first threshold value is a threshold value that is used for determining whether the micro-vibration operation is to be performed or whether nothing has to be performed. A second threshold value is a threshold value that is set to a value lower than the first threshold value, indicative of a state that sedimentation of the solid particles has advanced to some extent, and used for determining whether the micro-vibration operation alone is to be performed or whether the refresh is to be performed. - The
CPU 101 first compares a detection result of the liquid dropletspeed detection apparatus 3 with the first threshold value and determines whether the detection result is lower than the first threshold value so that sedimentation of the solid particles has advanced and hence the micro-vibration operation should be performed (S21) . As a result, when the detection result is not lower than the first threshold value, it is determined that sedimentation of the solid particles in theink chambers 11 has not advanced and hence the nozzle recovery operation is not required, and the nozzle recovery operation is not carried out in the non-print region. Therefore, the wasteful consumption of the ink and the contamination of the periphery due to the satellite can be suppressed. - On the other hand, if it was determined that the detection result was lower than the first threshold value, the detection result is then compared with the second threshold value (S22) . As a result, if it was determined that the detection result was lower than the second threshold value, then the refresh constituted of the micro-vibration operation and the ejection operation is started (S23) . Furthermore, if it was determined that the detection result was not lower than the second threshold value, it is determined that sedimentation of the solid particles has advanced to some extent but the refresh does not have to be carried out, and then the micro-vibration operation alone is performed (S24).
- As a result, it is possible to take an appropriate action in accordance with a state of the ink in the
ink chambers 11. If performing the micro-vibration operation alone is selected, since the liquid droplets are not ejected, and hence the wasteful consumption of the ink and the contamination of the periphery due to the satellite can be suppressed. - Moreover, in place of the detection result of the liquid droplet
speed detection apparatus 3, as shown inFIG. 12 , a detection result of the liquid droplet ejection pause period can be used as a trigger. That is, when thehead 1 first reaches the non-print region, a liquid droplet ejection pause period of eachnozzle 12 in the print region is first detected based on print data (S30). The detection result is transmitted to theCPU 101. - Additionally, the
CPU 101 first compares the detection result of the ejection pause period with the first threshold value and determines whether the detection result exceeds the first threshold value and sedimentation of the solid particles has advanced so that the micro-vibration operation should be performed (S31) . As a result, when the detection result is lower than the first threshold value, it is determined that sedimentation of the solid particles in eachink chamber 11 has not advanced so that the nozzle recovery operation does not have to be performed, and the nozzle recovery operation is not performed in the non-print region. Therefore, the wasteful consumption of the ink and the contamination of the periphery due to the satellite can be suppressed. - On the other hand, if the detection result was determined to exceed the first threshold value, the detection result is compared with the second threshold value set to a value higher than the first threshold value (S32). As a result, if the detection result was determined to likewise exceed the second threshold value, then the refresh constituted of the micro-vibration operation and the ejection operation is started (S33). Further, if it was determined that the detection result was yet to exceed the second threshold value, the solid particles are determined to settle out to some extent, but the refresh does not have to be carried out, and then the micro-vibration operation alone is carried out (S34). As a result, the same effect as that in case of detecting an ejection speed of the liquid droplets can be provided.
- In such cases, if the plurality of
heads 1 are provided in accordance with the respective colors, an ejection speed or an ejection pause period of the liquid droplets is detected in accordance with each head, and whether the micro-vibration operation alone is performed or whether the refresh is performed is determined, thereby executing an appropriate nozzle recovery operation in accordance with eachhead 1. - Furthermore, in each flow shown in
FIG. 11 andFIG. 12 , when thehead 1 reaches the non-print region, the micro-vibration operation may be always carried out. In this case, one set value can suffice as a threshold value, and whether the micro-vibration operation alone is to be performed or whether the refresh constituted of the micro-vibration operation and the ejection operation is to be performed may be determined based on comparison with this threshold value. - Besides, whether the micro-vibration operation alone is to be performed or whether the refresh is to be performed may be selected and executed in accordance with a preset sequence. For example, a selection trigger may be set by the number of times that the
head 1 reaches the non-print region, the micro-vibration operation may be always performed every time thehead 1 is present in the non-print region, and the refresh constituted of the micro-vibration operation and the ejection operation may be performed every time thehead 1 reaches the non-print region for the third time. Moreover, the selection trigger may be set by a time, the micro-vibration operation may be performed in a regular situation, and the refresh constituted of the micro-vibration operation and the ejection operation alone may be effected at start of printing or every time a predetermined time passes after execution of the previous refresh. - Meanwhile, a sedimentation speed of the solid particles rises as specific gravity of the solid particles relative to the dispersion medium increases, and hence sedimentation is facilitated. For example, even if the same head is used, when types of inks to be used differ, specific gravity of the solid particles relative to the dispersion medium may differ in levels in some cases. Furthermore, in case of using a plurality of
heads 1, types of the solid particles contained in the ink differ depending on types (colors) of the inks for therespective heads 1, and hence the specific gravity of the solid particles relative to the dispersion medium may differ in levels . In such a case, when the uniformed micro-vibration operation is performed irrespective of a level difference in specific gravity of the solid particles relative to the dispersion medium, a situation where the solid particles cannot be sufficiently dispersed depending on levels of specific gravity can be expected. - Therefore, at the time of micro-vibrating the ink in each
ink chamber 11 by using the micro-vibration pulse P2, it is preferable to raise an application frequency as the specific gravity increases in accordance with a level of the specific gravity of the solid particles relative to the dispersion medium. When the application frequency of the micro-vibration pulse P2 is raised as the specific gravity increases, the ink in eachink chamber 11 can be efficiently micro-vibrated, and dispersion of the solid particles can be effectively facilitated. - A level of the specific gravity of the solid particles relative to the dispersion medium can be manually set by, e.g., providing a non-illustrated input switch to the liquid
droplet ejection apparatus 100 and performing an input operation by an operator in accordance with a type of the ink at the time of setting an ink tank or an ink cartridge storing the ink to the apparatus, or it may be automatically set by recognizing identifying information of the type of the ink provided on the ink tank or the ink cartridge with the use of non-illustrated recognizing means provided to the liquiddroplet ejection apparatus 100. The input result or the identification result is transmitted to theCPU 101, and themicro-vibration control unit 107 controls the micro-vibration operation based on the input result or the identification result. -
FIG. 13 shows an example of a table that is preferably used at the time of adjusting an application frequency in accordance with a level of the specific gravity of the solid particles relative to the dispersion medium. In this table, a relationship between a level of the specific gravity of the solid particles relative to the dispersion medium (a ratio of a specific gravity difference of the solid particles relative to specific gravity of the dispersion medium) and an application frequency of the micro-vibration pulse, and it is stored in, e.g., theCPU 101. Moreover, when an input or identified level of the specific gravity of the solid particles relative to the dispersion medium is relatively small, a sedimentation speed of the solid particles is relatively slow, and hence the application frequency is reduced, and the application frequency is raised as the level of the specific gravity increases. As a result, it is possible to execute the fine micro-vibration operation according to a difference in level of the sedimentation seed of the solid particles, thereby further efficiently recovering the nozzles. - As shown in
FIG. 14 , the ink in thecommon ink chamber 13 in thehead 1 can be circulated between thecommon ink chamber 13 and theink tank 4 storing the ink. Asupply pipe 41 and areturn pipe 42 are connected between thecommon ink chamber 13 of thehead 1 and theink tank 4, acirculation pump 43 is provided to thereturn pipe 42, and thesupply pipe 41, thereturn pipe 42, and thecirculation pump 43 constitute circulating means. Further, the ink is circulated between theink tank 4 and thecommon ink chamber 13 of thehead 1 by drive of thecirculation pump 43. As a result, since the solid particles of the ink stored in thecommon ink chamber 13 can have uniform concentration, the ink in which the solid particles having the uniform concentration can be supplied to theink chambers 11. As a result, sedimentation of the solid particles in the ink in theink chambers 11 can be further suppressed, and an ink replacement effect based on the refresh can be improved. - Although it is desirable to constantly perform this ink circulating operation based on drive of the
circulation pump 43 irrespective of a case where thehead 1 is present in the print region and a case where it is present in the non-print region, the ink in eachink chamber 11 can be replaced with an ink having uniform concentration at the time of refresh, and hence it is preferable to carry out the ink circulating operation at least during a period that the refresh constituted of the micro-vibration operation and the ejection operation is performed. - As nozzle maintenance means (a nozzle maintenance process) that performs maintenance for recovery of the
nozzles 12, there are known means that perform a wiping operation (a wiping process) for wiping off stains on each nozzle surface with the use of a blade, a removing operation (a removing process) for pressing a water-absorptive member such as cloth against each nozzle surface and removing the ink, and others when thehead 1 is present in the non-print region, any one or more of these means may be provided in the liquiddroplet ejection apparatus 100 and carried out. In this case, it is preferable to prevent both the micro-vibration operation and the ejection operation from being performed during a period where the nozzle maintenance means (the nozzle maintenance process) is carried out. In particular, when the micro-vibration operation alone is performed as the nozzle recovery operation, since a meniscus in thenozzle 12 vibrates by micro-vibration, and hence the meniscus may be destroyed at the time of the wiping operation or the removing operation. - As the above-described liquid
droplet ejection apparatus 100, the line type liquid droplet ejection apparatus that performs printing on a surface of a recording medium in one pass has been described, but the liquid droplet ejection apparatus may be a scan type liquid droplet ejection apparatus that performs printing by reciprocating thehead 1 in a main scan direction. -
FIG. 15 shows an example of such a scan type liquid droplet ejection apparatus. - In a liquid
droplet ejection apparatus 200, a recording medium W is sandwiched between a pair ofconveyance rollers 201 and conveyed in a direction indicated by an arrow (a sub-scan direction) by aconveyance roller 203 that is driven to rotate by aconveyance motor 202 . - A
head 1 is provided between theconveyance roller 203 and the pair ofconveyance rollers 201 so as to face a surface of the recording medium W. Thehead 1 is arranged and mounted on acarriage 204 in such a manner that a nozzle surface side faces the recording medium W. Thecarriage 204 is provided to enable its reciprocating motion along a left-and-right direction in the drawing (the main scan direction) substantially orthogonal to a conveyance direction (the sub-scan direction) of the recording medium W by non-illustrated driving means alongguide rails 205 installed along a width direction of the recording medium W. - The
head 1 horizontally scans and moves on the surface of the recording medium W with movement of thecarriage 204 in the main scan direction, and ejecting the liquid droplets from thenozzles 12 in this scanning and moving process enables performing desired printing. - In this liquid
droplet ejection apparatus 200, both lateral sides of the recording medium W are non-print regions in which no print data is provided and printing based on the print data is not performed. In the non-print regions,ink receivers 206 are arranged at positions facing the nozzle surfaces of thehead 1. Therefore, at the time of performing refresh when thehead 1 reaches the non-print region, the liquid droplets are ejected toward theink receivers 206. In case of installing the liquid dropletspeed detection apparatus 3 shown inFIG. 7 , this apparatus can be arranged in each of the non-print regions on both sides of the recording medium W. - In the
head 1 explained above, the energy giving means in which eachpartition wall 14 between the neighboringink chambers piezoelectric partition wall 14 and which ejects the ink in theink chambers 11 as liquid droplets from thenozzles 12 by a deforming operation of eachpartition wall 14 has been described as the example, but a specific structure of the energy giving means for giving energy to the ink in the ink chamber is out of the question. For example, a heater may be provided in the ink chambers as the energy giving means, air bubbles may be generated in the ink by energizing the heater, and the liquid droplets may be ejected from the nozzles by a breaking function of the air bubbles, or one wall surface of the ink chamber may be formed of a diaphragm as the energy giving means, this diaphragm may be vibrated by a deforming operation of the piezoelectric element, the ink in the ink chamber may be given energy, and the liquid droplets may be ejected from the nozzles. - Moreover, the
head 1 is not restricted to a head in which nozzle surfaces are arranged to be vertically downward directed, and nozzle surfaces may be arranged in a horizontal direction or an oblique direction. - As shown in
FIG. 15 , a scan type liquid droplet ejection apparatus having ink receivers arranged in non-print regions on both lateral sides of a recording medium was used, predetermined printing was performed in a print region of the recording medium from a head using a UV ink containing a dispersion medium and a titanium oxide in which solid particles have specific gravity higher than that of the dispersion medium (a specific gravity difference between the dispersion medium and the solid particles: 0.25, the content of a material having a steam pressure higher than that of wafer at an ordinary temperature: 5%), a micro-vibration pulse having a frequency that is a half of a liquid droplet ejection frequency at the time of printing was applied every time the head reached the non-print region in order to turn back at an end portion in a main scan direction, and then liquid droplets having the same frequency as the ejection frequency were ejected into each ink receiver. - As a result, even though the operation was continuously performed for 120 hours or more, nozzle clogging did not occur, and the stable operation was possible.
- The continuous operation was performed under the same conditions as those in Example 1 except that the micro-vibration pulse was not applied in each non-print region and the ejection operation alone was performed.
- As a result, nozzle clogging occurred in an ink chamber at the end portion when five hours passed from the operation.
- The continuous operation was performed under the same conditions as those in Example 1 except that the micro-vibration pulse alone was applied in each non-print region and the ejection operation was not performed.
- As a result, nozzle clogging occurred in an ink chamber at the end portion when five hours passed from the operation.
- As shown in
FIG. 1 , a line type liquid droplet ejection apparatus that performs printing on a surface of each ceramic tile conveyed by a conveyance belt in one pass from a head was used, and predetermined printing was performed in a print region on the ceramic tile surface from the head using an oil ink containing a dispersion medium and pigment particles of yellow as solid particles (a specific gravity difference between the dispersion medium and the solid particles: 0.30, the content of a material having a steam pressure higher than that of water at an ordinary temperature: 3%). Since the oil ink for the ceramic tile has high density and the pigment particles are apt to settle out, the micro-vibration pulse having the same frequency as a liquid droplet ejection frequency at the time of printing was applied, and then liquid droplets having the same frequency as the ejection frequency were ejected into each ink receiver. - As a result, even though the operation was continuously performed for 120 hours or more, nozzle clogging did not occur, and the stable operation was possible.
- The continuous operation was performed under the same conditions as those in Example 2 except that the ejection operation alone was performed without applying a micro-vibration pulse in each non-print region.
- As a result, nozzle clogging occurred in the ink chamber at the end portion when five hours passed from the operation.
-
- 1 : head
- 11 : ink chamber
- 12 : nozzle
- 13 : common ink chamber
- 14 : partition wall
- 15 : nozzle plate
- 2 : conveyance belt
2a : conveyance surface - 3 : liquid droplet speed detection apparatus
- 31 : light projection unit
- 32 : light receiving unit
- 4 : ink tank
- 41 : supply pipe
- 42 : return pipe
- 43 : circulation pump
- 100 : liquid droplet ejection apparatus
- 101 : CPU
- 102 : print data memory
- 103 : encoder
- 104 : belt conveyance motor
- 105 : head driver
- 106 : drive pulse generation unit
- 107 : micro-vibration control unit
- 108 : ejection control unit
- 200 : liquid droplet ejection apparatus
- 201 : pair of conveyance rollers
- 202 : conveyance motor
- 203 : conveyance roller
- 204 : carriage
- 205 : guide rail
- 206 : ink receivers
- P1 : ejection pulse
- P2 : micro-vibration pulses
- C : ceramic tile
- L : detection light
- W: recording medium
- a : liquid droplet
Claims (18)
- A liquid droplet ejection apparatus (100) comprising:a head (1) that includes an ink chamber (11) into which an ink is supplied, a nozzle (12) provided in accordance with the ink chamber, and an energy giving device (14) that drives when at least one drive pulse is applied thereto and gives energy to the ink in the ink chamber, the head performing printing on a print region of a recording medium (C) based on print data by ejecting liquid droplets from the nozzle; anda drive pulse generation device (106) that generates, as the drive pulse, at least one ejection pulse that is used for ejecting the liquid droplets from the nozzle and at least one micro-vibration pulse that micro-vibrates the ink in the ink chamber so as not to eject the liquid droplets from the nozzle,the ink, wherein the ink contains a dispersion medium and solid particles having higher specific gravity than that of a dispersion medium, a difference between the specific gravity of the dispersion medium and that of the solid particles being 0.2 or more and a content of a material, whose steam pressure at an ordinary temperature is higher than that of water, being 10% or less,the liquid droplet ejection apparatus comprises a refresh device (107, 108) that is used when the head is present in a non-print region where the printing is not performed, andthe refresh device performs a micro-vibration operation that applies the plurality of micro-vibration pulses to the energy giving device such that the solid particles that are settled and aggregated in the ink chamber are brought to a state in which the solid particles can smoothly be dispersed, and an ejection operation that applies the plurality of ejection pulses to the energy giving device after the micro-vibration operation and ejects a liquid droplet amount equal to or greater than a volume of the ink chamber from the nozzle to replace all of the ink in the ink chamber.
- The liquid droplet ejection apparatus (100) according to claim 1, comprising a liquid droplet speed detection device (3) that detects a speed of the liquid droplets ejected from the nozzle (12) when the head (1) is present in the non-print region where printing is not performed,
wherein the refresh device (107, 108) is executed after detecting that a detection result of the liquid droplet speed detection device falls below a preset threshold value. - The liquid droplet ejection apparatus (100) according to claim 1, comprising a pause period detection device that detects a period during which ejection of the liquid droplets from the nozzle (12) pauses when the head (1) is present in the print region where the printing is carried out,
wherein the refresh device (107, 108) is executed after detecting that a detection result of the pause period detection device exceeds a preset threshold value. - The liquid droplet ejection apparatus (100) according to claim 1, further comprising:a micro-vibration device (107) that exclusively performs the micro-vibration operation that applies the plurality of micro-vibration pulses to the energy giving device (14) when the head (1) is present in the non-print region where the printing is not performed; anda selection device that selects and executes one of the micro-vibration device and the refresh device.
- The liquid droplet ejection apparatus (100) according to claim 4, comprising a liquid droplet speed detection device (3) that detects a speed of the liquid droplets ejected from the nozzle (12) when the head (1) is present in the non-print region where the printing is not performed,
wherein the selection device selects and executes one of the micro-vibration device (107) and the refresh device (107, 108) in accordance with a detection result of the liquid droplet speed detection device (3) after detecting that the detection result falls below a preset threshold value. - The liquid droplet ejection apparatus (100) according to claim 4, comprising a pause period detection device that detects a period during which ejection of the liquid droplets from the nozzle (12) pauses when the head (1) is present in the print region where the printing is performed,
wherein the selection device selects and executes one of the micro-vibration device (107) and the refresh device (107, 108) in accordance with a detection result of the pause period detection device after detecting that the detection result exceeds a preset threshold value. - The liquid droplet ejection apparatus (100) according to any one of claims 1 to 6,
wherein, in the micro-vibration operation, an application frequency is raised as specific gravity of the solid particles relative to the dispersion medium increases in accordance with the specific gravity. - The liquid droplet ejection apparatus (100) according to any one of claims 1 to 7, comprising:an ink tank (4) that stores the ink that is supplied to the head (1); anda circulation device (43) that circulates the ink between the head and the ink tank,wherein the circulation device circulates the ink during a period that at least the refresh device (107, 108) is executed.
- The liquid droplet ejection apparatus (100) according to any one of claims 1 to 8, comprising a nozzle maintenance device that executes at least one of a wiping operation for wiping off stains on a nozzle surface in which the nozzle (12) is opened and a removing operation for removing the ink on the nozzle surface when the head (1) is present in the non-print region where the printing is not performed,
wherein both the micro-vibration device (107) and the refresh device (107, 108) are not executed during a period that the nozzle maintenance device is executed. - A method for recovering a nozzle (12) of a liquid droplet ejection apparatus (100) comprising:a head (1) that includes an ink chamber (11) into which an ink is supplied, a nozzle (12) provided in accordance with the ink chamber, and an energy giving device (14) that drives when at least one drive pulse is applied thereto and gives energy to the ink in the ink chamber, the head performing printing on a print-region of a recording medium (C) based on print data by ejecting liquid droplets from the nozzle; anda drive pulse generation device (106) that generates, as the drive pulse, at least one ejection pulse that is used for ejecting the liquid droplets from the nozzle and at least one micro-vibration pulse that micro-vibrates the ink in the ink chamber so as not to eject the liquid droplets from the nozzle,the ink, wherein the ink contains a dispersion medium and solid particles having higher specific gravity than that of a dispersion medium, a difference between the specific gravity of the dispersion medium and that of the solid particles being 0.2 or more and a content of a material, whose steam pressure at an ordinary temperature is higher than that of water, being 10% or less, andthe method comprises a refresh process (S3, S12, S23, S33) that is performed when the head is present in a non-print region where the printing is not performed, andthe refresh process performs a micro-vibration operation that applies the plurality of micro-vibration pulses to the energy giving device such that the solid particles that are settled and aggregated in the ink chamber are brought to a state in which the solid particles can smoothly be dispersed, and an ejection operation that applies the plurality of ejection pulses to the energy giving device after the micro-vibration operation and ejects a liquid droplet amount equal to or greater than a volume of the ink chamber from the nozzle to replace all of the ink in the ink chamber.
- The method for recovering a nozzle (12) of a liquid droplet ejection apparatus (100) according to claim 10, comprising a liquid droplet speed detection process (S1, S20) that detects a speed of the liquid droplets ejected from the nozzle when the head (1) is present in the non-print region where printing is not performed,
wherein the refresh process (S3, S23) is executed after detecting that a detection result of the liquid droplet speed detection process falls below a preset threshold value (S2, S22) . - The method for recovering a nozzle (12) of a liquid droplet ejection apparatus (100) according to claim 10, comprising a pause period detection process (S10, S30) that detects a period during which ejection of the liquid droplets from the nozzle pauses when the head (1) is present in the print region where the printing is carried out,
wherein the refresh process (S12, S33) is executed after detecting that a detection result of the pause period detection process exceeds a preset threshold value (S11, S32). - The method for recovering a nozzle (12) of a liquid droplet ejection apparatus (100) according to claim 10, further comprising:a micro-vibration process (S24, S34) that exclusively performs the micro-vibration operation that applies the plurality of micro-vibration pulses to the energy giving device (14) when the head (1) is present in the non-print region where the printing is not performed,wherein one of the micro-vibration process or the refresh process (S23, S33) is selected and executed.
- The method for recovering a nozzle (12) of a liquid droplet ejection apparatus (100) according to claim 13, comprising a liquid droplet speed detection process (S20) that detects a speed of liquid droplets ejected from the nozzle when the head (1) is present in the non-print region where the printing is not performed,
wherein one of the micro-vibration process (S24) and the refresh process (S23) is selected and executed in accordance with a detection result of the liquid droplet speed detection process after detecting that the detection result falls below a preset threshold value (S22). - The method for recovering a nozzle (12) of a liquid droplet ejection apparatus (100) according to claim 13, comprising a pause period detection process (S30) that detects a period during which ejection of the liquid droplets from the nozzle pauses when the head (1) is present in the print region where the printing is performed,
wherein one of the micro-vibration process (S34) and the refresh process (S33) is selected and executed in accordance with a detection result of the pause period detection process after detecting that the detection result exceeds a preset threshold value (S32). - The method for recovering a nozzle (12) of a liquid droplet ejection apparatus (100) according to any one of claims 10 to 15,
wherein, in the micro-vibration operation (S24, S34), an application frequency is raised as specific gravity of the solid particles relative to the dispersion medium increases in accordance with the specific gravity. - The method for recovering a nozzle (12) of a liquid droplet ejection apparatus (100) according to any one of claims 10 to 16, comprising an ink tank (4) that stores the ink that is supplied to the head (1),
wherein the ink is circulated between the head and the ink tank during a period that at least the refresh process (S3, S12, S23, S33) is executed. - The method for recovering a nozzle (12) of a liquid droplet ejection apparatus (100) according to any one of claims 10 to 17, comprising a nozzle maintenance process that executes at least one of a wiping process for wiping off stains on a nozzle surface in which the nozzle is opened and a removing process for removing the ink on the nozzle surface when the head (1) is present in the non-print region where the printing is not performed,
wherein both the micro-vibration process (S24, S34) and the refresh process (S23, S33) are not executed during a period that the nozzle maintenance process is executed.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013131601A JP2015003495A (en) | 2013-06-24 | 2013-06-24 | Droplet ejection device and nozzle recovery method of the same |
Publications (3)
Publication Number | Publication Date |
---|---|
EP2837497A2 EP2837497A2 (en) | 2015-02-18 |
EP2837497A3 EP2837497A3 (en) | 2015-05-20 |
EP2837497B1 true EP2837497B1 (en) | 2019-10-02 |
Family
ID=50976478
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP14172583.8A Active EP2837497B1 (en) | 2013-06-24 | 2014-06-16 | Liquid droplet ejection apparatus and method for recovering nozzle of liquid droplet ejection apparatus |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP2837497B1 (en) |
JP (1) | JP2015003495A (en) |
CN (1) | CN104228349B (en) |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6611164B2 (en) * | 2015-09-25 | 2019-11-27 | 芝浦メカトロニクス株式会社 | Tablet printing apparatus and tablet printing method |
CN105235391B (en) * | 2015-10-27 | 2017-08-04 | 深圳市润天智数字设备股份有限公司 | Bidirectional drawing type digital spraying print machine |
DE102016100036A1 (en) * | 2016-01-04 | 2017-07-06 | Océ Holding B.V. | Control module for inserting print image-dependent pre-fire pulses in an inkjet printing system |
WO2018001441A1 (en) * | 2016-06-27 | 2018-01-04 | Hewlett-Packard Development Company, L.P. | Printhead recirculation |
JP7019303B2 (en) * | 2017-03-24 | 2022-02-15 | 東芝テック株式会社 | Droplet dispenser |
CN110214087B (en) * | 2017-04-21 | 2021-02-05 | 惠普发展公司,有限责任合伙企业 | Method of fluid recirculation in a printhead, printing system, and computer readable medium |
EP3953185A1 (en) * | 2019-04-12 | 2022-02-16 | Ball Corporation | Method of maintaining inkjet printhead meniscus |
JP7326899B2 (en) * | 2019-06-12 | 2023-08-16 | 京セラドキュメントソリューションズ株式会社 | Inkjet recording device |
US20220324226A1 (en) * | 2021-04-13 | 2022-10-13 | Hewlett-Packard Development Company, L.P. | Drop-based remedial actions for a printhead |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3056191B1 (en) | 1999-01-12 | 2000-06-26 | 新潟日本電気株式会社 | Driving apparatus and method for ink jet printer head |
JP3659494B2 (en) * | 2001-05-16 | 2005-06-15 | セイコーエプソン株式会社 | Liquid ejector |
JP2008149703A (en) * | 2006-11-23 | 2008-07-03 | Ricoh Co Ltd | Image forming apparatus and printed matter |
GB0724606D0 (en) | 2007-12-18 | 2008-01-30 | Xennia Technology Ltd | Recirculating ink system for industrial inkjet printing |
JP2009154328A (en) * | 2007-12-25 | 2009-07-16 | Fuji Xerox Co Ltd | Liquid droplet discharge head and image forming apparatus equipped with the same |
JP5239931B2 (en) * | 2008-05-30 | 2013-07-17 | セイコーエプソン株式会社 | Fluid ejection device |
JP2012096423A (en) | 2010-11-01 | 2012-05-24 | Seiko Epson Corp | Liquid ejecting apparatus and control method |
US9067414B2 (en) * | 2011-04-19 | 2015-06-30 | Canon Kabushiki Kaisha | Liquid ejection head and method of driving the same |
-
2013
- 2013-06-24 JP JP2013131601A patent/JP2015003495A/en active Pending
-
2014
- 2014-06-16 EP EP14172583.8A patent/EP2837497B1/en active Active
- 2014-06-24 CN CN201410285814.4A patent/CN104228349B/en active Active
Non-Patent Citations (1)
Title |
---|
None * |
Also Published As
Publication number | Publication date |
---|---|
CN104228349A (en) | 2014-12-24 |
EP2837497A3 (en) | 2015-05-20 |
JP2015003495A (en) | 2015-01-08 |
EP2837497A2 (en) | 2015-02-18 |
CN104228349B (en) | 2016-07-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2837497B1 (en) | Liquid droplet ejection apparatus and method for recovering nozzle of liquid droplet ejection apparatus | |
EP2837498B1 (en) | Liquid droplet injection apparatus and method for recovering nozzle of liquid droplet injection apparatus | |
US8511793B2 (en) | Ejection surface cleaning apparatus, liquid ejection apparatus and ejection surface cleaning method | |
US9039114B2 (en) | Inkjet recording apparatus | |
JP2018089834A (en) | Recording device and recording method | |
US9498958B2 (en) | Liquid jetting apparatus | |
JP2010240894A (en) | Filter device, channel unit, fluid supply device, and fluid jetting device | |
US11618260B2 (en) | Liquid ejecting apparatus and maintenance method of liquid ejecting apparatus | |
JP2015174424A (en) | Liquid discharge device and circulation flow rate adjustment method | |
JP2022129724A (en) | inkjet printer | |
JP7130572B2 (en) | inkjet printer and computer program | |
JP2005225214A (en) | Liquid jetting device and maintenance method therefor | |
JP2008229863A (en) | Fluid jetting apparatus | |
EP1795356A1 (en) | A method for increasing the reliability of an inkjet printing system | |
JP6569577B2 (en) | Ink jet recording apparatus and refresh method for ink jet recording apparatus | |
US7384120B2 (en) | Inkjet recording method and inkjet recording apparatus | |
JP5897886B2 (en) | Inkjet recording apparatus and recording method | |
JP2008246952A (en) | Maintenance method for inkjet recorder | |
JP2009143155A (en) | Recording device and control method for recording device | |
JP4609101B2 (en) | Liquid ejecting apparatus and liquid ejecting apparatus cleaning method | |
JP2007268964A (en) | Method and apparatus for inkjet recording | |
JP2006224359A (en) | Liquid jetting apparatus and method for recovering delivering capability of liquid jetting apparatus | |
JP2014024258A (en) | Inkjet recording device | |
JP2006240169A (en) | Ink-jet recording device and preliminary ejection method | |
KR20240028133A (en) | Substrate treating apparatus and substrate treating method |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
17P | Request for examination filed |
Effective date: 20140616 |
|
AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
PUAL | Search report despatched |
Free format text: ORIGINAL CODE: 0009013 |
|
AK | Designated contracting states |
Kind code of ref document: A3 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
RIC1 | Information provided on ipc code assigned before grant |
Ipc: B41J 2/165 20060101AFI20150416BHEP Ipc: B41J 2/045 20060101ALI20150416BHEP |
|
R17P | Request for examination filed (corrected) |
Effective date: 20151120 |
|
RBV | Designated contracting states (corrected) |
Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: GRANT OF PATENT IS INTENDED |
|
INTG | Intention to grant announced |
Effective date: 20190410 |
|
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: KOBAYASHI, RYOHEI |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE PATENT HAS BEEN GRANTED |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP Ref country code: AT Ref legal event code: REF Ref document number: 1185743 Country of ref document: AT Kind code of ref document: T Effective date: 20191015 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R096 Ref document number: 602014054464 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: MP Effective date: 20191002 |
|
REG | Reference to a national code |
Ref country code: LT Ref legal event code: MG4D |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: MK05 Ref document number: 1185743 Country of ref document: AT Kind code of ref document: T Effective date: 20191002 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200103 Ref country code: NO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200102 Ref country code: PL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: NL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: ES Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: LT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: AT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: SE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: LV Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: BG Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200102 Ref country code: FI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200203 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CZ Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200224 Ref country code: RS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: HR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R097 Ref document number: 602014054464 Country of ref document: DE |
|
PG2D | Information on lapse in contracting state deleted |
Ref country code: IS |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: EE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: RO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200202 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: SM Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 |
|
26N | No opposition filed |
Effective date: 20200703 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MC Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200616 |
|
REG | Reference to a national code |
Ref country code: BE Ref legal event code: MM Effective date: 20200630 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200630 Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200630 Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200616 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200630 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: TR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: MT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191002 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: PLFP Year of fee payment: 10 |
|
P01 | Opt-out of the competence of the unified patent court (upc) registered |
Effective date: 20230510 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20240402 Year of fee payment: 11 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20240328 Year of fee payment: 11 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20240408 Year of fee payment: 11 |