EP0947327A2 - Tête d'impression à jet d'encre, procédé de commande et imprimante à jet d'encre utilisant une telle tête - Google Patents

Tête d'impression à jet d'encre, procédé de commande et imprimante à jet d'encre utilisant une telle tête Download PDF

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Publication number
EP0947327A2
EP0947327A2 EP99106686A EP99106686A EP0947327A2 EP 0947327 A2 EP0947327 A2 EP 0947327A2 EP 99106686 A EP99106686 A EP 99106686A EP 99106686 A EP99106686 A EP 99106686A EP 0947327 A2 EP0947327 A2 EP 0947327A2
Authority
EP
European Patent Office
Prior art keywords
pressure chamber
ink
pressure
piezoelectric transducers
voltage
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.)
Ceased
Application number
EP99106686A
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German (de)
English (en)
Other versions
EP0947327A3 (fr
Inventor
Kazuhiro Shimoyama
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by NEC Corp filed Critical NEC Corp
Publication of EP0947327A2 publication Critical patent/EP0947327A2/fr
Publication of EP0947327A3 publication Critical patent/EP0947327A3/fr
Ceased legal-status Critical Current

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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
    • B41J2/015—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
    • B41J2/04573—Timing; Delays
    • 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
    • B41J2/135—Nozzles
    • B41J2/14—Structure thereof only for on-demand ink jet heads
    • B41J2/14201—Structure of print heads with piezoelectric elements
    • B41J2/14233—Structure of print heads with piezoelectric elements of film type, deformed by bending and disposed on a diaphragm
    • 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
    • B41J2/14—Structure thereof only for on-demand ink jet heads
    • B41J2002/14338—Multiple pressure elements per ink chamber

Definitions

  • the present invention relates to an ink-jet print head, a driving method thereof and an ink-jet printer using the same.
  • the present invention relates to, in particular, a drop-on-demand type ink-jet print head for discharging ink using piezoelectric transducers, a driving method thereof and an inkjet printer using the same.
  • the displacement amount of a piezoelectric transducer in a pressure chamber provided per nozzle is changed, the sizes of ink droplets discharged from the nozzle are made variable to thereby output multi-gradation images at high resolution.
  • FIG. 13 is a block diagram of ink channels of the ink jet head disclosed therein.
  • each communication hole 51 communicating with a nozzle 52 is tapered and becomes gradually small toward the direction of the nozzle 52.
  • the hole 51 is provided with two pressure chambers 53 opposite to each other or offset each other in opposite directions. Side walls constituting the pressure chambers 53 are coupled to the communication holes while they form spirals in the same rotation direction in the vicinity of the holes 51.
  • ink flows are simultaneously generated from the pressure chambers 53 communicating with the same communication hole 51 by the piezoelectric transducers, respectively, then the flows applied with rotation by the side walls turn into eddy flows and run into the communication hole 51. The flows are superimposed to thereby discharge large ink droplets from the nozzle 52.
  • the ink droplet volume discharged from the nozzle is changed by selecting and driving one of or both of the two piezoelectric transducers installed on the two pressure chambers communicating with the single communication hole.
  • ink is discharged at right angle with the flow direction of ink generated in the pressure chamber and pressure chambers are coupled to each other through large openings, respectively. Due to this, it is difficult to efficiently make use of the energy applied onto the piezoelectric transducers for purposes of discharging ink.
  • an object of the present invention to provide an ink-jet print head which can be easily manufactured and capable of multistage-varying ink droplets discharged from a nozzle without causing a reduction in print speed and without using an expensive layered piezoelectric transducer having great output changes.
  • An ink-jet print head includes a plurality of pressure chamber rows formed by connecting a plurality of pressure chambers in series through a supply path having a smaller channel area than the pressure chambers; a plurality of piezoelectric transducers provided in the pressure chambers, respectively and applied with voltage waveforms independently of one another; an ink pool communicating with a pressure chamber located on one end of each of the pressure chamber rows; and a plurality of nozzles each communicating with a pressure chamber located on the other end of the pressure chamber row.
  • an ink-jet printer includes the above-stated print head; a voltage applied device selection unit for selecting piezoelectric transducers applied with voltage wave forms based on ink droplets discharged from the respective nozzles for every pressure chamber row; and a plurality of voltage waveform application units for sequentially applying voltage waveforms to the piezoelectric transducers selected by the voltage applied device selection unit at voltage wave form application timing, at which voltage waveforms are sequentially applied to piezoelectric transducers of the first pressure chamber to the second pressure chamber for every pressure chamber row, the timing delayed in phase by 1/2 of natural periods of pressure waves in pressure chambers with respect to pressure chambers connected to one another on a ink pool side.
  • pressure chambers are connected, in series, to one another between the nozzle and the ink pool and provided With piezoelectric transducers, respectively.
  • the piezoelectrc transducers are sequentially and selectively driven with phase differences by 1/2 of natural periods of pressure waves in the respective pressure chambers given.
  • the sizes of ink droplets discharged from the nozzle at a time can be varied in a plurality of stages.
  • the pressure chamber rows include pressure chambers having different pressure wave natural periods of the pressure chambers.
  • another ink-jet printer includes the above-stated another ink-jet print head; a voltage applied device selection unit for selecting piezoelectric transducers applied with voltage waveforms and maximum voltages of the voltage waveforms applied to the piezoelectric transducers; and a plurality of voltage waveform application units for generating voltage wave forms having maximum voltages for the piezoelectric transducers selected by the voltage applied device selection unit and sequentially applying the voltage waveforms to the selected piezoelectric transducers at voltage waveform application timing, at which voltage waveforms are sequentially applied to piezoelectric transducers of the pressure chamber connected to the ink pool to the pressure chamber connected to the nozzle for every pressure chamber row, the timing delayed in phase by 1/2 of pressure wave natural periods of pressure chambers with respect to pressure chambers connected to one another on a ink pool side.
  • piezoelectric transducers applied with voltage waveforms are selected, voltage waveforms having the selected maximum voltages are generated for the selected piezoelectric transducers and the generated voltage waveforms are applied to the selected transducers.
  • FIG. 1 is a perspective view showing the constitution of a print head in the first embodiment according to the present invention.
  • the print head consists of a nozzle plate 4, a head substrate and a diaphragm 2 on which a plurality of piezoelectric transducers 1a, 1b and 1c are provided.
  • An ink pool 8 and pressure chambers 6a, 6b, 6c connected to the ink pool 8 through the supply port 7a, 7b, 7c are formed on the upper surface of the head substrate.
  • the head substrate is formed out of a dry film on a base such as an SUS by means of photolithography, the pressure chambers and supply path can be easily formed into desired shapes.
  • the substrate is formed out of ceramic by means of integral burning, the rigidity of the pressure chambers can increase and pressurizing energy loss can be reduced.
  • a plurality of pressure chambers 6a, 6b and 6c are substantially aligned in series and connected to the nozzle 5.
  • the pressure chambers 6a, 6b and 6c are formed to have a predetermined uniform depth. If the pressure chambers 6a, 6b and 6c have large areas corresponding to the diaphragm 2 with respect to the heights of the chambers, it is possible to obtain sufficient pressure even with a single layered piezoelectric transducer with small displacement amount. In addition, it is preferable that corners R are provided in respective corners of the pressure chambers so as not to keep bubble remaining in the chambers.
  • Supply ports 7a, 7b and 7c each having a predetermined length and a narrower width are provided in connecting portions between the respective pressure chambers 6a, 6b and 6c and the ink pool 8, respectively, to maintain pressurizing force within the chambers.
  • the cross-section area and length of a supply port are determined by the relationship between pressurizing force loss within a pressure chamber and ink refill time after ink is supplied. Since they contradict against each other, they need to be determined to obtain desired discharge characteristics.
  • the connecting portions between the pressure chambers 6a, 6b, 6c and the supply ports 7a, 7b and 7c are provided with tapered portions or corner R portions as required so as to prevent cavitations due to the generation of eddy and sharp change of pressure. It is noted that the tapered or corner R portions may be provided in depth direction.
  • tapered or corner portions R may be formed in both thickness and width directions.
  • the directions of the supply ports in front or back of the respective pressure chambers 6a, 6b and 6c are oriented in the same direction.
  • the shape of the supply ports 7a, 7b, 7c allows pressurizing energy generated within the respective pressure chamber 6a, 6b and 6c to efficiently act on the discharge of ink.
  • the diaphragm 2 is provided to propagate pressuring force of the piezoelectric transducers 1a, 1b, 1c to ink within pressure chambers.
  • the diaphragm 2 is made of SUS material or the like having only the portion, to which the piezoelectric transducers 1a, 1b, 1c are attached, formed to be sufficiently thin by means of, for example, electroforming so as to propagate pressurizing force to ink within the pressure chambers without preventing the deformation of the piezoelectric transducer 1a.
  • the piezoelectric transducers 1a, 1b and 1c for converting electric signals to mechanical energy corresponding to the respective pressure chamber 6a, 6b and 6c are connected to the diaphragm 2.
  • signal lines 9a, 9b, 9c and 10 for transmitting electric signals to these piezoelectric transducers are formed on the surface of the diaphragm 2.
  • a waveform generation circuit A 12 which generates waveforms to discharge large ink droplets, a waveform generation circuit B 13 which generates waveforms to discharge middle-size ink droplets and a waveform generation circuit C 14 which generates waveforms to discharge small ink droplets are connected to a switch 15. Output from the selected circuit by the switch 15 is supplied to the piezoelectric transducer 1c of the pressure chamber closest to the ink pool 8 through the switch 17.
  • a waveform delayed from a drive waveform applied to the piezoelectric transducer 1c through a delay circuit 16 for generating a delay by 1/2 of the natural period of pressure wave in the pressure chambers 6a, 6b, 6c is applied to the piezoelectric transducer 1b closer to the nozzle than the transducer 1c through the switch 17.
  • the drive waveform outputted from the delay circuit 16 is further inputted into another delay circuit and delayed.
  • the delayed drive waveform is then applied to the piezoelectric transducer 1a closest to the nozzle 5. While referring to an ink droplet volume table 19, switches 15 and 17 are selected by a waveform and device selection circuit 18 so as to drive necessary piezoelectric transducers with the most suitable drive waveforms for obtaining desired ink droplets.
  • Ink is supplied from the ink pool 8 through a plurality of supply paths and pressure chambers to the nozzle 5 and is filled therein.
  • a waveform and device selection circuit 18 calculates ink droplet volume to be discharged from respective nozzles connected to respective rows of pressure chambers (step S1).
  • a waveform and device selection circuit 18 selects waveforms and piezoelectric transducers to apply the drive waveform (step S2).
  • a waveform and device selection circuit 18 may be connected to, for example, a ink droplet volume table 19 storing the relations between ink droplet volume to be discharged and waveforms and piezoelectric transducers to be selected, and select the appropriate drive waveform and piezoelectric transducer to discharge the ink droplet volume required.
  • the number N of the pressure chamber to be operated is set to 1 (step S3).
  • a waveform and device selection circuit 18 judges whether the piezoelectric transducer of the pressure chamber of No. N is one selected in the step S2 (step S4). If the piezoelectric transducer is to be selected, a waveform and device selection circuit 18 applies the drive waveform selected by the switch 15 to the piezoelectric transducer of the pressure chamber N (step S5).
  • a drive waveform selected by the switch 15 is applied, as a print signal, to the piezoelectric transducer 1c opposite to the pressure chamber 6c in closest proximity of the ink pool 8 through the signal line 9c.
  • the voltage of the drive waveform may increase linearly from 0V to a predetermined drive voltage at predetermined rise time and is held to have a predetermined maximum drive voltage for a predetermined time period, as shown in FIG. 4.
  • the drive of the drive waveform linearly may fall from the predetermined voltage to 0V at predetermined fall time, as shown in FIG. 4.
  • a waveform and device selection circuit 18 does not applies the drive waveform selected by the switch 15 to the piezoelectric transducer of the pressure chamber N.
  • a waveform and device selection circuit 18 increments the number N. That is, the next pressure chamber for the nozzle becomes the object to be operated (step S6).
  • a waveform and device selection circuit 18 judges whether the piezoelectric transducer of the pressure chamber N is one selected in the step S2 (step S7) If the piezoelectric transducer of the pressure chamber N is one selected, a delay circuit 16 forms a waveform delayed in phase by 1/2 of the natural period of the pressure wave in the pressure chamber N compared to the drive waveform applied to the pressure chamber N-1 (step S8).
  • Output from the delay circuit 16 is applied to the piezoelectric transducer of the pressure chamber N (step S9) That is to say, the piezoelectric transducer 1b opposite to the pressure chamber 6b next to the pressure chamber 6c is applied with the drive waveform 11b with phase difference as shown in FIG. 4, for example. If the piezoelectric transducer of the pressure chamber N is judged to be different from the one selected in step S7, a waveform and device selection circuit 18 does not applies the drive waveform selected by the switch 15 to the piezoelectric transducer of he pressure chamber N.
  • a waveform and device selection circuit 18 judges whether the piezoelectric transducer of the pressure chamber N is last one which connects to the nozzle (step S10). If the piezoelectric transducer of the pressure chamber N is not last one, a waveform and device selection circuit 18 increments the number N (step S11) and return to the step S7.
  • drive waveforms 11a, 11b and 11c applied to the piezoelectric transducers 1a, 1b and 1c corresponding to the respective pressure chambers may be the same as shown in FIG. 4.
  • phase differences given to these drive waveforms are 1/2 time difference of fundamental natural time periods for the pressure waves in the respective pressure chambers.
  • the phase difference given to the drive wave form may be taken as 1/2 time difference of n-th natural period which is one n-th, where n is an integer, of the basic natural period for the pressure waves for the respective pressure chambers or as 1/2 time difference of n-th natural period considering that pressure energy is added almost in the same manner. It is noted that it is most efficient to use the phase difference based on the fundamental natural period.
  • the drive wave form 11a having a phase difference is applied to the piezoelectric transducer 1a opposite to the pressure chamber 6a connected to the nozzle 5.
  • the pressure energy within the pressure chamber 6a is added to the pressuring energy propagating from the pressure chamber 6b. If the combined energy reaches the nozzle 5, an ink cylinder protrudes from the nozzle 5 and ink is discharged therefrom. The quantity of ink within the pressure chamber 6a is reduced due to the discharge of ink.
  • Ink is then supplied from the ink pool 8 through the ink supply paths 7a, 7b, 7c and pressure chambers 6b, 6c into the pressure chamber by the capillary action of the nozzle 5 and the quantity of ink is recovered to the original level, thus completing a series of operations.
  • FIG. 5 shows a waveform in a case where small ink droplets are discharged.
  • FIG. 6 shows a waveform in a case where large ink droplets are discharged.
  • Drive displacement amount is set by changing pressure energy, more specifically, by changing voltage waveforms applied to the piezoelectric transducers. To discharge small drops of ink, drive voltage is increased, drive time is shortened and rise time and fall time are shortened as shown in FIG. 5. Conversely, to discharge large drops of ink, drive voltage is decreased, drive time is lengthened and rise and fall time are lengthened as shown in FIG. 6.
  • the ink droplet discharge rate should not be changed between a case where small drops of ink are discharged and a case where large drops of ink are discharged so as to make the ink droplet position constant.
  • ink droplets can be adjusted by changing the number and combination of selected piezoelectric transducers for applying drive waveforms, in a multistage manner stably or without providing a drive circuit for generating many drive waveform patterns.
  • the piezoelectric transducers of all of the pressure chambers are applied with drive waveforms to thereby change the waveforms.
  • the piezoelectric transducer 1a of the pressure chamber 6a closest to the nozzle 5 and one of the piezoelectric transducers of the remaining two pressure chambers are applied with drive waveforms to thereby change the waveforms.
  • the piezoelectric transducer of the remaining pressure chamber is not applied with a drive waveform. If the pressure chamber 6c farthest from the nozzle is selected, energy loss exists since pressure wave passes through the supply port 7b until pressure wave propagates to the pressure chamber 6a closest to the nozzle. For that reason, the size of ink droplets applied to the pressure chamber 6a is smaller than that applied to the pressure chamber 6b even if the same energy is applied to them.
  • the combination of the number of drive transducers and drive waveforms, by which ink droplets closest to desired ink droplets are obtained, is selected and the piezoelectric transducers in accordance with the selected number of the drive transducers are applied with selected drive waveforms.
  • a plurality of pressure chambers necessary to discharge micro-drops and having short natural periods are coupled to one another. This makes it possible to discharge micro-drops to large drops from a single nozzle. Owing to this, it is possible to obtain high-speed, inexpensive, high quality print outputs without the need to overstrike on a dot and use many-valued density ink to express an image by gradations.
  • the piezoelectric transducers are applied with the same drive waveforms which are delayed respectively. It is also possible to select different waveforms and apply them to the piezoelectric transducers. By doing so, far more types of ink droplets can be discharged.
  • a piezoelectric transducer is used as a transducer for converting an electric signal for generating pressurizing force in the pressure chamber 6 into mechanical energy.
  • the piezoelectric transducer may be a single layered piezoelectric transducer or multi-layered piezoelectric transducer.
  • three sets of pressure chambers and supply ports are connected in series. At least two sets suffice to provide the same advantage.
  • FIG. 7 is a perspective cross-sectional view showing the structure of a print head in the second embodiment according to the present invention.
  • the print head in this embodiment differs from that in the first embodiment in that three pressure chambers 26a, 26b and 26c coupled to one another through supply ports 7 are formed in different sizes.
  • the sizes of pressure chambers are set smaller so that the natural periods of pressure waves are made shorter as the pressure chambers are closer to the nozzle 5.
  • the sizes of the pressure chambers are set such that the natural period of pressure wave in the pressure chamber 26b closer to the nozzle 5 than the pressure chamber 26c adjacent to an ink pool 8 is shorter than that in the pressure chamber 26c and that the pressure wave natural period in the pressure chamber 6a closer to the nozzle 5 than the pressure chamber 26b is shorter than that in the pressure chamber 26b.
  • the sizes of piezoelectric transducers 21a, 21b and 21c driving the pressure chambers 26a, 26b and 26c, respectively are set according to the sizes of the corresponding pressure chambers.
  • a print head drive circuit in the second embodiment according to the present invention differs from that in the first embodiment in that the piezoelectric transducers 21a, 21b and 21c are applied with drive waveforms of different maximum voltages.
  • drive waveform attenuation circuits 32 and 33 for attenuating the maximum voltages of drive waveforms are provided between switches 17 connected to the piezoelectric transducers 21a, 21b and delay circuits 16 for delaying the timing of a voltage waveform outputted from a waveform generation circuit 31, respectively.
  • the waveform generation circuit 31 may have the three waveform generation circuits described in the first embodiment contained therein and a drive waveform generated from one of the contained circuits may be selected by a selection circuit which is not shown. Needless to say, the waveform generation circuit 31 may be structured to output only one type of waveform.
  • a device and maximum voltage selection circuit 34 calculates ink droplet volume to be discharged from respective nozzles connected to respective pressure chamber rows (step S1). Next, based on respective ink droplet volume to be discharged, a device and maximum voltage selection circuit 34 selects piezoelectric transducers to apply the drive waveform and maximum voltages of voltage waveform to be applied to these selected piezoelectric transducers (step S21). The number N of the pressure chamber to be operated is set to 1 (step S3). A device and maximum voltage selection circuit 34 judges whether the piezoelectric transducer of the pressure chamber of No. N is one selected in the step S2 (step S4). If the piezoelectric transducer is to be selected, a device and maximum voltage selection circuit 34 applies the drive waveform having the selected maximum voltage to the piezoelectric transducer of the pressure chamber N (step S22).
  • a device and maximum voltage selection circuit 34 does not applies the drive waveform to the piezoelectric transducer of the pressure chamber N.
  • a device and maximum voltage selection circuit 34 increments the number N. That is, the next pressure chamber for the nozzle becomes the object to be operated (step S6).
  • a device and maximum voltage selection circuit 34 judges whether the piezoelectric transducer of the pressure chamber N is one selected in the step S2 (step S7). If the piezoelectric transducer of the pressure chamber N is to be selected, a delay circuit 16 forms a waveform having the selected maximum voltage and delayed in phase by 1/2 of the natural period of the pressure wave in the pressure chamber N with comparison to the drive waveform applied to the pressure chamber N-1 (step S23).
  • the formed drive waveform is applied to the piezoelectric transducer of the pressure chamber N (step S9) If the piezoelectric transducer of the pressure chamber N is judged to be different from the one selected in step S7, a device and maximum voltage selection circuit 34 does not applies the drive waveform to the piezoelectric transducer of the pressure chamber N.
  • a device and maximum voltage selection circuit 34 judges whether the piezoelectric transducer of the pressure chamber N is last one connected to the nozzle (step S10). If the piezoelectric transducer of the pressure chamber N is not last one, a waveform and device selection circuit 18 increments the number N (step S11) and return to the step S7.
  • the waveform generation circuit 31 may include 3 waveform generation circuits and switch as described in the first embodiment. The waveform generation circuit 31 may output only one waveform, too.
  • the drive waveform attenuation circuit 32 When a waveform as shown in, for example, FIG. 10 is inputted, the drive waveform attenuation circuit 32 outputs a waveform which maximum voltage is attenuated while time from the start of the rise of the inputted waveform until the end of the fall thereof and rise/fall voltage gradients are not changed.
  • the print head drive circuit shown in FIG. 8 respectively applies drive waveforms 41a, 41b and 41c shown in FIG. 12 to the piezoelectric transducers 21a, 21b, 21c.
  • the drive waveform 41b is delayed by 1/2 of the natural period for the pressure chamber 26b with respect to the drive waveform 41c by the delay circuit 16 and the maximum voltage of the drive waveform 41b is attenuated by the drive waveform attenuation circuit 32.
  • the drive waveform 41a is delayed by 1/2 of the natural period for the pressure chamber 26a with respect to the waveform 41b by the delay circuit 16 and the maximum voltage of the waveform 41a is attenuated more greatly than the waveform 41b by the drive waveform attenuation circuit 33.
  • the maximum voltages of the drive waveforms applied to the piezoelectric transducers 21a and 21b are attenuated more greatly than the maximum voltage of the drive waveform applied to the piezoelectric transducer 21c. By doing so, the piezoelectric transducers 21a, 21b and 21c corresponding to the respective pressure chambers are applied with waveforms of different maximum voltages.
  • the pressure chambers have different sizes and the settings of maximum voltages of drive waveforms are different, thereby allowing the combination of the types of ink droplets to be freely selected.
  • plural sets of pressure chambers and supply ports are arranged to be coupled to one another in series between the nozzle and the ink pool.
  • the piezoelectric transducers corresponding to the respective pressure chambers are arranged.
  • the piezoelectric transducers are selectively driven, it is possible to change diameters of drops from small drops requiring a pressure chamber having a short natural period to large drops requiring great changes in the volume of pressure chambers.

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  • Particle Formation And Scattering Control In Inkjet Printers (AREA)
EP99106686A 1998-04-02 1999-04-01 Tête d'impression à jet d'encre, procédé de commande et imprimante à jet d'encre utilisant une telle tête Ceased EP0947327A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP8996998 1998-04-02
JP8996998 1998-04-02

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Publication Number Publication Date
EP0947327A2 true EP0947327A2 (fr) 1999-10-06
EP0947327A3 EP0947327A3 (fr) 2001-03-14

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EP99106686A Ceased EP0947327A3 (fr) 1998-04-02 1999-04-01 Tête d'impression à jet d'encre, procédé de commande et imprimante à jet d'encre utilisant une telle tête

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EP (1) EP0947327A3 (fr)
AU (1) AU739877B2 (fr)
CA (1) CA2267921A1 (fr)

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Publication number Priority date Publication date Assignee Title
EP1329318A2 (fr) * 2002-01-18 2003-07-23 Illinois Tool Works, Inc. Appareil d'éjection de fluide pouvant moduler le volume de goutte
EP1488927A1 (fr) * 2003-06-20 2004-12-22 C.R.F. Società Consortile per Azioni Méthode et dispositif d'éjection de micro-gouttes de liquide

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DE4201923A1 (de) * 1991-01-28 1992-08-06 Fuji Electric Co Ltd Tintenstrahlaufzeichnungskopf
EP0738599A2 (fr) * 1995-04-19 1996-10-23 Seiko Epson Corporation Tête d'enregistrement à jet d'encre et procédé pour sa fabrication
JPH08309971A (ja) * 1995-05-16 1996-11-26 Brother Ind Ltd インクジェットプリンタヘッド

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JP3156583B2 (ja) * 1995-04-19 2001-04-16 セイコーエプソン株式会社 インクジェット式印字ヘッドの駆動装置
JPH1016211A (ja) * 1996-07-05 1998-01-20 Seiko Epson Corp インクジェット式記録装置
JP3324429B2 (ja) * 1997-02-14 2002-09-17 ミノルタ株式会社 インクジェット記録装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4201923A1 (de) * 1991-01-28 1992-08-06 Fuji Electric Co Ltd Tintenstrahlaufzeichnungskopf
EP0738599A2 (fr) * 1995-04-19 1996-10-23 Seiko Epson Corporation Tête d'enregistrement à jet d'encre et procédé pour sa fabrication
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1329318A2 (fr) * 2002-01-18 2003-07-23 Illinois Tool Works, Inc. Appareil d'éjection de fluide pouvant moduler le volume de goutte
EP1329318A3 (fr) * 2002-01-18 2003-11-26 Illinois Tool Works, Inc. Appareil d'éjection de fluide pouvant moduler le volume de goutte
US6921158B2 (en) 2002-01-18 2005-07-26 Illinois Tool Works, Inc. Fluid ejection device with drop volume modulation capabilities
EP1488927A1 (fr) * 2003-06-20 2004-12-22 C.R.F. Società Consortile per Azioni Méthode et dispositif d'éjection de micro-gouttes de liquide

Also Published As

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AU2354899A (en) 1999-10-14
EP0947327A3 (fr) 2001-03-14
CA2267921A1 (fr) 1999-10-02
AU739877B2 (en) 2001-10-25

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