EP1241007A1 - Droplet deposition apparatus and methods of manufacture thereof - Google Patents
Droplet deposition apparatus and methods of manufacture thereof Download PDFInfo
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- EP1241007A1 EP1241007A1 EP02010145A EP02010145A EP1241007A1 EP 1241007 A1 EP1241007 A1 EP 1241007A1 EP 02010145 A EP02010145 A EP 02010145A EP 02010145 A EP02010145 A EP 02010145A EP 1241007 A1 EP1241007 A1 EP 1241007A1
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Images
Classifications
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- 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
- B41J2/16—Production of nozzles
- B41J2/1607—Production of print heads with piezoelectric elements
- B41J2/1609—Production of print heads with piezoelectric elements of finger type, chamber walls consisting integrally of piezoelectric material
-
- 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
- B41J2/14209—Structure of print heads with piezoelectric elements of finger type, chamber walls consisting integrally of piezoelectric material
-
- 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
- B41J2/16—Production of nozzles
- B41J2/1621—Manufacturing processes
- B41J2/1623—Manufacturing processes bonding and adhesion
-
- 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
- B41J2/16—Production of nozzles
- B41J2/1621—Manufacturing processes
- B41J2/1632—Manufacturing processes machining
- B41J2/1634—Manufacturing processes machining laser machining
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- 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
- B41J2/16—Production of nozzles
- B41J2/1621—Manufacturing processes
- B41J2/1637—Manufacturing processes molding
-
- 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
- B41J2/16—Production of nozzles
- B41J2/1621—Manufacturing processes
- B41J2/164—Manufacturing processes thin film formation
- B41J2/1643—Manufacturing processes thin film formation thin film formation by plating
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- 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
- B41J2002/14387—Front shooter
-
- 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
- B41J2202/00—Embodiments of or processes related to ink-jet or thermal heads
- B41J2202/01—Embodiments of or processes related to ink-jet heads
- B41J2202/12—Embodiments of or processes related to ink-jet heads with ink circulating through the whole print head
Definitions
- the present invention relates to droplet deposition apparatus, in particular an inkjet printhead, which comprise a channel communicating with a supply of droplet liquid and an opening for ejection of droplets therefrom, at least one channel side wall being displaceable in response to electrical signals, thereby to effect ejection of droplets from the channel.
- Figure 1a is a cross-sectional view of the channels of the prior art inkjet printhead construction according to WO92/22429, belonging to the present applicant and incorporated herein by reference.
- Piezoelectric ceramic sheet 12 is poled in its thickness direction 17 and formed in one surface with channels 11 bounded on two sides lying parallel to the channel axis by channel walls 13.
- electrodes 23 formed on either side of each wall 13
- an electric field can be applied to the piezoelectric material of the walls, causing them to deflect in shear mode in a direction transverse to the channel axis.
- Pressure waves are thereby generated in the ink which result in the ejection of an ink droplet.
- Channels 11 are closed along one side lying parallel to the channel axis by the surface of a cover 14 having conductive tracks 16 at the same pitch interval as the ink channels formed thereon. Solder bonds 28 are formed between tracks 16 and the channel wall electrodes 23, thereby securing the cover to the base and creating an electrical connection between the electrodes and the track in a single step. To protect them from later being corroded by the ink, electrodes and tracks are then given a passivant coating.
- a nozzle plate 20 having respective ink ejection nozzles 22 is mounted at the front of the sheet 12 whilst an ink manifold 26 is defined at the rear by a manifold structure 21.
- Tracks 16 are led to the rear of cover 14 for connection to a drive circuit, typically embodied in a microchip 27 which in turn is driven by signal received via input tracks 18.
- the channel walls - and in particular the electrodes formed thereon - are often passivated so as to protect from subsequent corrosion by the ink.
- WO95/07820 incorporated herein by reference.
- the present invention has as an objective a printhead construction that retains the connection advantages associated with the conductive tracks formed on the cover of the prior art construction and yet is amenable to passivation.
- the present invention consists in one aspect in droplet deposition apparatus comprising at least one channel having means for communicating with a supply of droplet liquid and an opening for ejection of droplets; the channel being bounded on at least one side lying parallel to the channel axis by a channel wall associated with actuator means; the actuator means effecting displacement of the channel wall in response to electrical signals, thereby to effect ejection of droplets from the channel; the channel being bounded on a further side lying parallel to the channel axis by a cover surface, the cover surface having formed thereon at least one conductive track for conveying electrical signals to said actuator means, the point of electrical connection between the track and the actuator means lying outside the channel.
- a corresponding method according to a first aspect of the invention consists in a method of manufacture of droplet deposition apparatus, the method comprising the steps of:
- the step of closing the channel results in the electrical connection of the conductive track and the actuator means, thereby simplifying the manufacturing process.
- the point of electrical connection may be sealed from ingress of droplet fluid from the channel.
- an area adjacent said channel has an electrically-conductive coating which is in electrical contact with the actuator means associated with at least one channel wall of said channel, the conductive track being in electrical contact with said electrically-conductive coating.
- said area is a groove.
- the groove may be of lesser depth than the channel.
- the groove may be co-linear with the channel.
- the groove may be sealed by sealing means against ingress of droplet fluid from the channel.
- the electrical contact is made by a deformable conductive material interposed between the electrically-conductive coating and the conductive track.
- the deformable conductive material may be solder.
- a protective coating is applied to the channel wall.
- said electrically-conductive coating further extends over at least a channel-facing surface of the channel wall, the protective coating being applied to said electrically-conductive coating.
- the protective coating may terminate in said area adjacent said channel.
- a protective coating may be applied to at least one of the channel walls prior to closing the channel by the cover.
- the method may comprise the further step of masking the point at which the conductive track and the actuator means are electrically connected prior to applying the protective coating to at least one of the channel walls.
- the sealing means extends over the termination of the protective coating in said area adjacent said channel.
- the tops of said channel walls may be attached to the cover surface by a nonconducting bond.
- the non-conductive bond is an adhesive bond.
- a plurality of channels are formed in an array, the channels lying parallel to one another and defining channel walls therebetween.
- the channel walls are preferably displaceable in response to electrical signals in a direction transverse to the axes of the channels and parallel to the channel array direction.
- the channel wall comprises piezoelectric material to which said electrical signals are applied.
- the piezoelectric material preferably deforms in shear mode when subject to said electrical signals.
- an electrode is formed on a channel-facing surface of the channel wall and the piezoelectric material is polarised in a direction perpendicular both to the array direction and to the channel axis.
- the body preferably comprises a sheet of piezoelectric material, the plurality of channels being formed in one surface of the sheet.
- the piezoelectric material is preferably polarised in a direction normal to the surface of the sheet.
- the cover is formed with ports for supply of droplet liquid into said channel.
- the first aspect of the invention also consists in droplet deposition apparatus comprising:
- a corresponding method of manufacture of a droplet deposition apparatus comprises the steps of:
- a second aspect of the present invention consists in droplet deposition apparatus comprising:
- FIG. 2 shows a sectional view along the channels of such a prior art printhead, with those features that correspond to figure 1 being denoted by corresponding reference numbers.
- Droplet ejection takes place from a nozzle 22 formed in the channel cover component 60 whilst droplet liquid is supplied to the channel via ports 33 formed in the channel base and which are typically connected in their turn to ink supply conduits (not shown) formed in a base component 35 that is separate from the piezoelectric channelled component 12.
- an opening communicating with a droplet ejection orifice is formed in the bottom surface of the channel, thereby allowing the cover component to incorporate ports for supply of ink into the channel.
- a further, separate base component is consequently no longer required.
- a third aspect of the invention provides droplet deposition apparatus comprising:
- Figure 3 illustrates a printhead according to a first embodiment of the first aspect of the present invention, with those features that are common to figure 3 and the prior art printhead of figures 1 and 2 being designated by common reference numerals.
- a piezoelectric ceramic body 12 poled in the thickness direction is formed with channels 11 separated by channel walls 13.
- electrodes 23 are formed along each wall 13 in the ink-containing channel 11 as well as extending along a rearward groove 100 to the rear face 130 of the body.
- a cover 14 a surface 15 of which closes the open side of each of the channels 11, a nozzle plate 20 with nozzles 22 for droplet ejection and a manifold for supply of ink into the channel in the form of a transverse cut in the body 12.
- Surface 15 of cover 14 has tracks 16 formed thereon (suitable processes are well know) which in turn are connected to microchip 27 (which is illustrated figuratively in figure 3 and not to scale) which in turn receives input signals from input tracks 18.
- a passivation layer 140 (not shown in figure 3 but indicated by dashed hatching in figure 4a) is applied over the entirety of the electrodes 23 (indicated by solid hatching in both figures 3 and 4a) in the channel and part way along the rearward groove 100.
- passivation is carried out before attachment of the cover and advantageously according to the method described in WO95/07820, belonging to the present applicant and incorporated herein by reference.
- a mechanical bond between body and surface 15 of cover 14 is achieved by means of adhesive layer 160, applied to the end surfaces of the walls 13 in the region of the channels 11 prior to assembly of cover and body and preferably in accordance with the method discussed in WO95/04658, belonging to the present applicant and incorporated herein by reference.
- Figure 4b illustrates the assembled printhead, with the adhesive bond being indicated at 220.
- Such a bond may indeed be tougher and have a longer fatigue life than the corresponding solder bond of the prior art construction described above.
- protrusion 170 comes into contact with electrode 23 and is deformed, thereby providing an effective electrical contact 200 between electrode 23 and track 16.
- a bead 190 of a sealing paste or high viscosity glue is also applied so as to form on assembly an ink seal 210 between the end of the ink channel 11 and the electrical contact 200.
- a seal protects the electrical contact from later corrosion by ink.
- the seal is positioned so as to straddle the free end 150 of the passivation layer 140, thereby preventing the seepage of ink under the passivation layer from where it might otherwise attack the electrode material 23.
- Figure 5 illustrates a second embodiment of the first aspect of the present invention.
- a ceramic piezoelectric body 290 is, as in the previous embodiment, poled in the thickness direction and formed with channels 11 separated by channel walls 13 which in turn have an electrode 23 formed on each side. Ink ejection, however, takes place from a centrally located nozzle 320 formed either directly in the cover 350 or, as shown, in a nozzle plate 330 communicating with the channel via an aperture 340 formed in the cover.
- Body 290 is additionally formed with two manifolds 310 for supply of from both ends of the channel, as indicated by arrows 300. A further structure (not shown) will supply the manifolds with ink from a reservoir.
- Such a "double-ended" printhead configuration is disclosed in WO91/17051, belonging to the present applicant and incorporated herein by reference, and has advantages in terms of a lower operating voltage over the "single-ended" configuration described above. Furthermore, the configuration of base 290 is suited to manufacture by moulding - a technique that is potentially more attractive from the point of view of manufacturability than conventional sawing techniques described in the aforementioned EP-A-0 364 136.
- connection of the channel electrode 23 to conductive tracks 370 formed on that surface of cover 350 facing body 290 is as already described with regard to figures 3, 4a and 4b, however, and is located in groove 360 formed at one side of the body 290.
- cover 350 is attached to the piezoelectric ceramic body by a conventional adhesive bond (not shown).
- the nozzle 320 may be formed in the cover 350 itself.
- the nozzle is formed by laser ablation as described, for example, in WO93/1591 incorporated herein by reference, and to this end the cover may be made of an easily ablatable material, suitably a polymer such as polyimide, polycarbonate, polyester or polyetheretherketone, typically of 50 ⁇ m thickness.
- the stiffness of a cover plate formed of such an easily ablatable material may be increased by application of a coating of stiffer material to the inner and outer surfaces of the ablatable cover plate.
- a coating of stiffer material particularly suitable for this purpose is silicon nitride: it can also be used as a passivant coating in the process of the aforementioned WO95/07820, is deposited as a smooth coating suitable for the subsequent application of a non-wetting coating, and will not short out electrodes of adjacent channels due to its nonconducting properties.
- Two layers of such a material placed either side of the polyimide cover and each having a thickness of around 5% of that of the cover (2.5 ⁇ m in the case of a 50 ⁇ m thick cover) will typically increase bending stiffness by a factor of 5-10 (based on standard compound beam theory and assuming a value of Young's Modulus for the stiffening material approximately 100 times greater than that of the polymer and good adhesion between the stiff and polymer materials).
- Such a thin layer has no significant effect on the ease with which the cover plate can be ablated to form a nozzle, particularly if the material of the layer itself is to some degree ablatable.
- the cover plate for an inkjet printer comprises a layer of a first, easily ablatable, material having further layers bonded on opposite sides thereof, the further layers each being of a material having a stiffness at least an order of magnitude greater than that of the first material and being of a thickness at least an order of magnitude less than that of the first layer.
- Piezoelectric ceramic body 400 is formed with channels 11, channel-separating walls 13 and electrodes 23 which are supplied with actuating signals via conductive tracks 410 connected to drive circuitry (not shown). Unlike previous embodiments, however, droplet ejection takes place from a nozzle 420 communicating with an opening 430 formed in the body 400 at the closed, bottom surface 440 of the channel 11 - this is in contrast to figure 5 where the nozzle 320 is located in a cover 350 closing the open, top side of the channel 11.
- Moulding is again the preferred method of manufacture of the channelled body 400, and the arrangement of figures 4a and 4b is again employed for electrical connection between the electrodes 23 and conductive tracks 410.
- Communication hole 430 may also be formed during the moulding process or may be formed subsequently, e.g. by means of a laser.
- Cover 450 no longer incorporates a nozzle but is instead formed with ink inlet ports 460. Such an arrangement has a lower component count than embodiments discussed earlier and has consequential manufacturing advantages.
- ink supply ports could be formed in the channelled component, e.g. at the channel ends.
- the printhead of figure 7 also employs a cover component 500 having ink inlet ports 520, 522 and 524 located at either end and in the middle of a channel 11 formed in a piezoelectric body 530.
- Channel walls are separated by a gap 540 into two sections 550,560 supplied by ports 520,522 and 522,524 respectively, with each section being independently actuable by means of respective electrodes 570, 580 driven by drive circuits (not shown) via conductive tracks 650,660.
- the conductive tracks 650,660 that electrically connect the channel electrodes to the drive chips are formed on the piezoelectric body itself, advantageously in the same step in which the electrodes 570,580 are deposited on the channel walls.
- Such an arrangement is known from EP-A-0 397 441, belonging to the applicant and incorporated herein by reference, and consequently will not be described in further detail here.
- Connection between track 650,660 and drive chip 590,600 may be achieved by any conventional method, including wire bonding or gold ball connection.
- Piezoelectric body 530 may be moulded: in addition to having clear manufacturing advantages, such a process permits the end of the channel 11 to be formed as illustrated in figure 8, namely with a smooth, continuous transition 700 from the top surface 720 of the body to both the channel wall 730 and the bottom, longitudinal surface 710 of the channel. This in turn avoids discontinuities in the subsequently-deposited electrode material and the associated heating effects which might have a deleterious effect on the operational life of the printhead as a whole.
- channels may be formed in the piezoelectric component by sawing using a disc cutter - as described e.g. in EP-A-0 309 148 - and illustrated in the sectional and detail sectional views of figures 9 and 10. It follows that the depth of the channel 11 will run out more gradually at each end, as shown at 800, and that the piezoelectric channel wall defined between adjacent sawn channels 11 will run continuously between the two active sections 550,560. However, a break 810 in the electrodes on the channel walls at a location between the two sections ensures that each the wall in active section can be actuated independently by signals supplied via electrical input 820. Such a break may be achieved e.g. by masking during deposition of the metal plating or by removal of the plating by a laser.
- Connection between the electrodes on the channel walls and the electrical input 820 may be achieved by any of the known techniques including wire bond between tracks formed in shallow "run-out" grooves formed in the area 900 rearward of the channel 11 (described in the aforementioned EP-A-0 364 136) or conductive adhesive (e.g. anisotropic conductive adhesive) between conductive tracks formed in area 900 on the surface of the piezoelectric sheet itself and (described in EP-A-0 397 441).
- each channel 11 is closed along its two active sections 550,560 by appropriate lengths 820,830 of a cover component 500 which is also formed with ports 520,522,540 that allow ink to be supplied to each channel active section and, optionally, allow ink to be circulated through each channel section for cleaning purposes, as is generally known.
- Ports may be positioned so as to define the edge of an active section, as in the case of port 522, in which case manufacture is simplified.
- the width of cover port 552 and the cover closing lengths 820, 803 are of the same order of magnitude, typically 2mm.
- Ink ejection from each active section is again via openings that communicate the channel with the opposite surface of the piezoelectric component (sheet 860) to that in which the channel is formed.
- these openings take the form of slots 840,850 which extend some distance - typically 200 ⁇ m - in the longitudinal direction of the channel so as to allow some leeway in the placing of the respective nozzles 870,880 in nozzle plate 890.
- Offsetting of nozzles is generally necessary whenever simultaneous droplet ejection from adjacent channels is not possible e.g. in "shared wall" printheads of the kind illustrated, is generally known e.g. from EP-A-0 376, and will not therefore be discussed in any greater detail.
- Printheads according to the present invention may also be made in a modular format as described in the aforementioned WO91/17051, each module being formed in opposite end surfaces thereof with respective channel parts so that, upon butting together of modules, further channels are formed between respective pairs of butted modules.
- the respective channel parts may include at least part of a slot formed in the channel base and of sufficient length that, even if a pair of butted modules and their respective slot parts are not perfectly aligned, there remains an overlap between the two slot halves sufficient to accommodate a nozzle.
- nozzles 870,880 are formed in a nozzle plate 890 which, as illustrated, may extend over the substantially the entire length of piezoelectric sheet 860 so as to provide a suitably large area for engagement e.g. of a capping and/or wiping mechanism.
- the piezoelectric channel walls can be polarised in opposite directions normal to the plane of the channel axes as known, for example, from EP-A-0 277 703 incorporated herein by reference.
- polarisation of the channel walls can be parallel to the plane of the channel axes with electrodes formed in the channel walls themselves as known, for example, from EP-A-0 528 647.
- active channels capable of droplet ejection may be alternated in the printhead with inactive - so-called "dummy" channels - as described, for example, in the aforementioned EP-A-0 277 703.
Abstract
Description
- The present invention relates to droplet deposition apparatus, in particular an inkjet printhead, which comprise a channel communicating with a supply of droplet liquid and an opening for ejection of droplets therefrom, at least one channel side wall being displaceable in response to electrical signals, thereby to effect ejection of droplets from the channel.
- Figure 1a is a cross-sectional view of the channels of the prior art inkjet printhead construction according to WO92/22429, belonging to the present applicant and incorporated herein by reference. Piezoelectric
ceramic sheet 12 is poled in itsthickness direction 17 and formed in one surface withchannels 11 bounded on two sides lying parallel to the channel axis bychannel walls 13. By means ofelectrodes 23 formed on either side of eachwall 13, an electric field can be applied to the piezoelectric material of the walls, causing them to deflect in shear mode in a direction transverse to the channel axis. Pressure waves are thereby generated in the ink which result in the ejection of an ink droplet. These principles are known in the art, e.g. from EP-A-0 364 136, belonging to the present applicant and incorporated herein by reference. -
Channels 11 are closed along one side lying parallel to the channel axis by the surface of acover 14 havingconductive tracks 16 at the same pitch interval as the ink channels formed thereon.Solder bonds 28 are formed betweentracks 16 and thechannel wall electrodes 23, thereby securing the cover to the base and creating an electrical connection between the electrodes and the track in a single step. To protect them from later being corroded by the ink, electrodes and tracks are then given a passivant coating. - As shown in figure 1b, which is a sectional view taken along the longitudinal axis A of a single channel of the prior art printhead of figure 1a, a
nozzle plate 20 having respectiveink ejection nozzles 22 is mounted at the front of thesheet 12 whilst anink manifold 26 is defined at the rear by amanifold structure 21.Tracks 16 are led to the rear ofcover 14 for connection to a drive circuit, typically embodied in amicrochip 27 which in turn is driven by signal received viainput tracks 18. - In printheads of this ilk, the channel walls - and in particular the electrodes formed thereon - are often passivated so as to protect from subsequent corrosion by the ink. Reference is made in this regard to WO95/07820, incorporated herein by reference.
- In the device discussed above, however, such conventional passivation prior to attachment of the cover would inhibit the formation of solder bonds between the electrodes and the tracks. On the other hand, passivation after the cover has been attached can only be applied from the end of the channel, resulting in low quality coating of the electrodes and tracks, especially at the midpoint of the channel remote from the channel ends.
- The present invention has as an objective a printhead construction that retains the connection advantages associated with the conductive tracks formed on the cover of the prior art construction and yet is amenable to passivation.
- Accordingly, the present invention consists in one aspect in droplet deposition apparatus comprising at least one channel having means for communicating with a supply of droplet liquid and an opening for ejection of droplets;
the channel being bounded on at least one side lying parallel to the channel axis by a channel wall associated with actuator means; the actuator means effecting displacement of the channel wall in response to electrical signals, thereby to effect ejection of droplets from the channel;
the channel being bounded on a further side lying parallel to the channel axis by a cover surface, the cover surface having formed thereon at least one conductive track for conveying electrical signals to said actuator means, the point of electrical connection between the track and the actuator means lying outside the channel. - Since the sole point of electrical connection between the track and the actuator in accordance with the present invention lies outside of the channel and thus out of contact with the ink (with its potentially corrosive effects), passivation of this point is no longer required. The channel itself can therefore be conventionally passivated via the open tops of the channels. Thereafter, the cover can be attached and electrical contact established between the conductive tracks on the cover and the actuator means associated with the channel walls. Even in a printhead that - because of the type of ink it is designed to fire - does not require passivation, a point of electrical connection lying outside the channel as per the present invention is less likely to fail in fatigue than the channel-length solder bonds of the prior art device of figures 1a,1b.
- A corresponding method according to a first aspect of the invention consists in a method of manufacture of droplet deposition apparatus, the method comprising the steps of:
- forming in a base component at least one open-topped channel and, bounding said channel on at least one side lying parallel to the channel axis, a channel wall associated with actuator means for effecting displacement of the channel wall in response to electrical signals, thereby to effect ejection of droplets from the channel;
- closing the channel on a further side lying parallel to the channel axis by a cover surface, the cover surface having formed thereon at least one conductive track for conveying electrical signals to said actuator means; and
- electrically connecting the conductive track and the actuator means at a point lying outside the channel.
-
- Advantageously, the step of closing the channel results in the electrical connection of the conductive track and the actuator means, thereby simplifying the manufacturing process.
- The point of electrical connection may be sealed from ingress of droplet fluid from the channel.
- Preferably an area adjacent said channel has an electrically-conductive coating which is in electrical contact with the actuator means associated with at least one channel wall of said channel, the conductive track being in electrical contact with said electrically-conductive coating.
- Preferably said area is a groove. The groove may be of lesser depth than the channel. The groove may be co-linear with the channel.
- The groove may be sealed by sealing means against ingress of droplet fluid from the channel.
- Preferably the electrical contact is made by a deformable conductive material interposed between the electrically-conductive coating and the conductive track. The deformable conductive material may be solder.
- Preferably a protective coating is applied to the channel wall. Preferably said electrically-conductive coating further extends over at least a channel-facing surface of the channel wall, the protective coating being applied to said electrically-conductive coating.
- The protective coating may terminate in said area adjacent said channel.
- A protective coating may be applied to at least one of the channel walls prior to closing the channel by the cover.
- The method may comprise the further step of masking the point at which the conductive track and the actuator means are electrically connected prior to applying the protective coating to at least one of the channel walls.
- Preferably the sealing means extends over the termination of the protective coating in said area adjacent said channel.
- The tops of said channel walls may be attached to the cover surface by a nonconducting bond. Preferably the non-conductive bond is an adhesive bond.
- Preferably a plurality of channels are formed in an array, the channels lying parallel to one another and defining channel walls therebetween. The channel walls are preferably displaceable in response to electrical signals in a direction transverse to the axes of the channels and parallel to the channel array direction.
- Preferably the channel wall comprises piezoelectric material to which said electrical signals are applied. The piezoelectric material preferably deforms in shear mode when subject to said electrical signals.
- Preferably an electrode is formed on a channel-facing surface of the channel wall and the piezoelectric material is polarised in a direction perpendicular both to the array direction and to the channel axis.
- The body preferably comprises a sheet of piezoelectric material, the plurality of channels being formed in one surface of the sheet. The piezoelectric material is preferably polarised in a direction normal to the surface of the sheet.
- Preferably the cover is formed with ports for supply of droplet liquid into said channel.
- The first aspect of the invention also consists in droplet deposition apparatus comprising:
- a bottom sheet of piezo-material poled in a direction normal to said sheet and formed with a multiplicity of parallel, open-topped channels mutually spaced in an array direction normal to the length of the channels and each defined by facing side walls and a bottom surface extending between said side walls;
- a top sheet facing said bottom surfaces of said channels and bonded to said side walls to close said channels at the tops thereof;
- respective nozzles communicating with said channels for the ejection of droplets of liquid therefrom;
- connection means for connecting said channels with a source of droplet deposition liquid;
- wherein each channel is formed with a forward part in which electrodes are provided on opposite sides of at least one of the side walls defining the channel, thereby to form a shear mode actuator for effecting droplet expulsion from the channel; and
- wherein each channel is formed with a rearward part having an electrically-conductive coating which is in electrical contact with the at least one electrode on the channel-facing sides of the side walls in the forward part;
- sealing means separating the forward part from the rearward part; and wherein
- the apparatus further comprises conductive tracks formed on that surface of said top sheet that is bonded to said side walls, the conductive tracks being in electrical contact with the electrically-conductive coating in said rearward part.
-
- A corresponding method of manufacture of a droplet deposition apparatus comprises the steps of:
- forming a bottom sheet with a layer of piezo-material poled in a direction normal to said sheet;
- forming a multiplicity of parallel, open-topped channels mutually spaced in an array direction normal to the length of the channels, each channel being defined by facing side walls and a bottom surface extending between said side walls, each channel further having a forward part and a rearward part;
- forming electrodes on opposite sides of at least one of the side walls defining the forward part of each channel, thereby to form a shear mode actuator for effecting droplet expulsion from the channel; and
- forming in the rearward part of each channel an electrically-conductive coating in electrical contact with a respective electrode;
- providing a top sheet having a surface formed with conductive tracks thereon; and
- bonding that surface of the top sheet having conductive tracks thereon to said side walls so as to close said channels at the tops thereof;
- establishing electrical contact between said tracks and the respective electrically -conductive coating of each channel; and
- providing sealing means separating the forward and rearward parts of each channel.
-
- A second aspect of the present invention consists in droplet deposition apparatus comprising:
- at least one longitudinal, open-topped droplet liquid channel defined by facing longitudinal side walls and a bottom, longitudinal surface extending between the side walls;
- means for applying an electric field to piezoelectric material in at least one of said walls, thereby to effect displacement of the wall relative to said longitudinal channel so as to eject a droplet from the channel; and
- a cover closing the open, longitudinal top side of the channel;
- wherein said bottom longitudinal surface of the channel is formed with an opening for droplet ejection, and;
- the cover incorporates two ports for supply of droplet liquid, the ports being spaced along the channel on either side of the opening.
-
- Such a construction again simplifies the manufacture of known printheads, particularly those of the top shooter kind discussed in WO91/17051 (belonging to the applicant and incorporated herein by reference). Figure 2 shows a sectional view along the channels of such a prior art printhead, with those features that correspond to figure 1 being denoted by corresponding reference numbers. Droplet ejection takes place from a
nozzle 22 formed in thechannel cover component 60 whilst droplet liquid is supplied to the channel viaports 33 formed in the channel base and which are typically connected in their turn to ink supply conduits (not shown) formed in abase component 35 that is separate from the piezoelectric channelledcomponent 12. - In accordance with the invention, an opening communicating with a droplet ejection orifice is formed in the bottom surface of the channel, thereby allowing the cover component to incorporate ports for supply of ink into the channel. A further, separate base component is consequently no longer required.
- A third aspect of the invention provides droplet deposition apparatus comprising:
- at least one longitudinal, open-topped droplet liquid channel defined by facing longitudinal side walls and a bottom, longitudinal surface extending between the side walls;
- means for supplying droplet liquid to the channel;
- means for applying an electric field to piezoelectric material in at least one of said walls, thereby to effect displacement of the wall relative to said longitudinal channel so as to eject a droplet from the channel; and
- a cover closing the open, longitudinal top side of the channel; wherein the bottom longitudinal surface of the channel is formed with two openings for droplet ejection, the openings being spaced along the channel.
-
- Such a construction brings to the arrangement of PCT application no. PCT/GB98/01495 - belonging to the present applicant and incorporated herein by reference - the aforementioned advantage of reduced component count.
- Corresponding method claims are also comprised in the present invention, and other aspects are as set out in other independent claims.
- Further advantageous embodiments of the invention are set out in the description, drawings and dependent claims.
- The disclosure of all claims is deemed incorporated here as consistory clauses, unless already set out above.
- The invention will now be described by way of example by reference to the following diagrams, of which:
- Figure 3 is a sectional view taken along the channel axis of a printhead according to a first embodiment of a first aspect of the present invention;
- Figures 4a and 4b show detail of the rear part of the printhead of figure 3 before and after attachment of the cover respectively;
- Figure 5 is a sectional view taken along the channel axis of a printhead according to a second embodiment of a first aspect of the present invention;
- Figure 6 is a sectional view taken along the channel axis of a printhead incorporating both first and second aspects of the present invention;
- Figure 7 is a sectional view taken along the channel axis of a printhead according to a second embodiment of a second aspect of the present invention;
- Figure 8 is a detail perspective view of the end of the piezoelectric body of the printhead of figure 7.
- Figures 9 and 10 are sectional and detail sectional views respectively of an alternative embodiment of the printhead shown in figure 7.
-
- Figure 3 illustrates a printhead according to a first embodiment of the first aspect of the present invention, with those features that are common to figure 3 and the prior art printhead of figures 1 and 2 being designated by common reference numerals.
- As in the prior art device, a piezoelectric
ceramic body 12 poled in the thickness direction is formed withchannels 11 separated bychannel walls 13. As known from EP-A-0 364 136 referred to above,electrodes 23 are formed along eachwall 13 in the ink-containingchannel 11 as well as extending along arearward groove 100 to therear face 130 of the body. In addition, there is provided acover 14, asurface 15 of which closes the open side of each of thechannels 11, anozzle plate 20 withnozzles 22 for droplet ejection and a manifold for supply of ink into the channel in the form of a transverse cut in thebody 12.Surface 15 ofcover 14 hastracks 16 formed thereon (suitable processes are well know) which in turn are connected to microchip 27 (which is illustrated figuratively in figure 3 and not to scale) which in turn receives input signals from input tracks 18. - Detail of the rear part of the printhead prior to attachment of the cover is shown in figure 4a: a passivation layer 140 (not shown in figure 3 but indicated by dashed hatching in figure 4a) is applied over the entirety of the electrodes 23 (indicated by solid hatching in both figures 3 and 4a) in the channel and part way along the
rearward groove 100. In contrast to the prior art construction, passivation is carried out before attachment of the cover and advantageously according to the method described in WO95/07820, belonging to the present applicant and incorporated herein by reference. - A mechanical bond between body and surface 15 of
cover 14 is achieved by means ofadhesive layer 160, applied to the end surfaces of thewalls 13 in the region of thechannels 11 prior to assembly of cover and body and preferably in accordance with the method discussed in WO95/04658, belonging to the present applicant and incorporated herein by reference. Figure 4b illustrates the assembled printhead, with the adhesive bond being indicated at 220. Such a bond may indeed be tougher and have a longer fatigue life than the corresponding solder bond of the prior art construction described above. - Electrical connection between the
conductive tracks 16 on the cover and that part of theelectrode 23 in therearward groove 100 is achieved by aprotrusion 170 of a malleable, deformable, conductive material such as solder affixed to theend 180 oftrack 16. On assembly of the cover to the body, as illustrated in figure 4b,protrusion 170 comes into contact withelectrode 23 and is deformed, thereby providing an effectiveelectrical contact 200 betweenelectrode 23 andtrack 16. - A
bead 190 of a sealing paste or high viscosity glue is also applied so as to form on assembly anink seal 210 between the end of theink channel 11 and theelectrical contact 200. Such a seal protects the electrical contact from later corrosion by ink. Preferably, the seal is positioned so as to straddle thefree end 150 of thepassivation layer 140, thereby preventing the seepage of ink under the passivation layer from where it might otherwise attack theelectrode material 23. - Figure 5 illustrates a second embodiment of the first aspect of the present invention. A ceramic
piezoelectric body 290 is, as in the previous embodiment, poled in the thickness direction and formed withchannels 11 separated bychannel walls 13 which in turn have anelectrode 23 formed on each side. Ink ejection, however, takes place from a centrally locatednozzle 320 formed either directly in thecover 350 or, as shown, in anozzle plate 330 communicating with the channel via anaperture 340 formed in the cover.Body 290 is additionally formed with twomanifolds 310 for supply of from both ends of the channel, as indicated byarrows 300. A further structure (not shown) will supply the manifolds with ink from a reservoir. - Such a "double-ended" printhead configuration is disclosed in WO91/17051, belonging to the present applicant and incorporated herein by reference, and has advantages in terms of a lower operating voltage over the "single-ended" configuration described above. Furthermore, the configuration of
base 290 is suited to manufacture by moulding - a technique that is potentially more attractive from the point of view of manufacturability than conventional sawing techniques described in the aforementioned EP-A-0 364 136. - The connection of the
channel electrode 23 toconductive tracks 370 formed on that surface ofcover 350 facingbody 290 is as already described with regard to figures 3, 4a and 4b, however, and is located ingroove 360 formed at one side of thebody 290. Similarly, in the region of the channel itself (the channel walls of which are passivated prior to assembly) and at thatend 380 of the body not occupied by an electrical connection,cover 350 is attached to the piezoelectric ceramic body by a conventional adhesive bond (not shown). - In order to minimise the distance travelled by the ink from the channel proper 11 to the outlet of the nozzle 320 - thereby reducing pressure losses and consequent reductions in droplet ejection velocity - the
nozzle 320 may be formed in thecover 350 itself. Advantageously the nozzle is formed by laser ablation as described, for example, in WO93/1591 incorporated herein by reference, and to this end the cover may be made of an easily ablatable material, suitably a polymer such as polyimide, polycarbonate, polyester or polyetheretherketone, typically of 50µm thickness. - The stiffness of a cover plate formed of such an easily ablatable material may be increased by application of a coating of stiffer material to the inner and outer surfaces of the ablatable cover plate. Particularly suitable for this purpose is silicon nitride: it can also be used as a passivant coating in the process of the aforementioned WO95/07820, is deposited as a smooth coating suitable for the subsequent application of a non-wetting coating, and will not short out electrodes of adjacent channels due to its nonconducting properties. Two layers of such a material placed either side of the polyimide cover and each having a thickness of around 5% of that of the cover (2.5µm in the case of a 50µm thick cover) will typically increase bending stiffness by a factor of 5-10 (based on standard compound beam theory and assuming a value of Young's Modulus for the stiffening material approximately 100 times greater than that of the polymer and good adhesion between the stiff and polymer materials). Such a thin layer has no significant effect on the ease with which the cover plate can be ablated to form a nozzle, particularly if the material of the layer itself is to some degree ablatable.
- Expressed in broad terms, the cover plate for an inkjet printer comprises a layer of a first, easily ablatable, material having further layers bonded on opposite sides thereof, the further layers each being of a material having a stiffness at least an order of magnitude greater than that of the first material and being of a thickness at least an order of magnitude less than that of the first layer.
- Referring now to figure 6, there is shown a printhead incorporating both first and second aspects of the present invention. Piezoelectric
ceramic body 400 is formed withchannels 11, channel-separatingwalls 13 andelectrodes 23 which are supplied with actuating signals viaconductive tracks 410 connected to drive circuitry (not shown). Unlike previous embodiments, however, droplet ejection takes place from anozzle 420 communicating with anopening 430 formed in thebody 400 at the closed,bottom surface 440 of the channel 11 - this is in contrast to figure 5 where thenozzle 320 is located in acover 350 closing the open, top side of thechannel 11. - Moulding is again the preferred method of manufacture of the channelled
body 400, and the arrangement of figures 4a and 4b is again employed for electrical connection between theelectrodes 23 andconductive tracks 410.Communication hole 430 may also be formed during the moulding process or may be formed subsequently, e.g. by means of a laser. Cover 450 no longer incorporates a nozzle but is instead formed withink inlet ports 460. Such an arrangement has a lower component count than embodiments discussed earlier and has consequential manufacturing advantages. Alternatively, ink supply ports could be formed in the channelled component, e.g. at the channel ends. - The printhead of figure 7 also employs a
cover component 500 havingink inlet ports channel 11 formed in apiezoelectric body 530. Channel walls are separated by agap 540 into two sections 550,560 supplied by ports 520,522 and 522,524 respectively, with each section being independently actuable by means ofrespective electrodes nozzle plate 615 and communicating with a section of thechannel 11 via communication holes 630,640 formed in the bottom surface of the channel at points located midway between the respective inlet ports for that section. - Such a configuration is described in co-pending UK patent application no. 9710530.8, belonging to the applicant and incorporated herein by reference, and results in a printhead having two parallel rows of independently actuable printing elements that is compact and which has a reduced actuating voltage per unit droplet ejection velocity due to the double-ended ink supply to each channel section.
- Unlike earlier embodiments, the conductive tracks 650,660 that electrically connect the channel electrodes to the drive chips are formed on the piezoelectric body itself, advantageously in the same step in which the electrodes 570,580 are deposited on the channel walls. Such an arrangement is known from EP-A-0 397 441, belonging to the applicant and incorporated herein by reference, and consequently will not be described in further detail here. Connection between track 650,660 and drive chip 590,600 may be achieved by any conventional method, including wire bonding or gold ball connection.
-
Piezoelectric body 530 may be moulded: in addition to having clear manufacturing advantages, such a process permits the end of thechannel 11 to be formed as illustrated in figure 8, namely with a smooth,continuous transition 700 from thetop surface 720 of the body to both thechannel wall 730 and the bottom,longitudinal surface 710 of the channel. This in turn avoids discontinuities in the subsequently-deposited electrode material and the associated heating effects which might have a deleterious effect on the operational life of the printhead as a whole. - Alternatively, channels may be formed in the piezoelectric component by sawing using a disc cutter - as described e.g. in EP-A-0 309 148 - and illustrated in the sectional and detail sectional views of figures 9 and 10. It follows that the depth of the
channel 11 will run out more gradually at each end, as shown at 800, and that the piezoelectric channel wall defined between adjacentsawn channels 11 will run continuously between the two active sections 550,560. However, abreak 810 in the electrodes on the channel walls at a location between the two sections ensures that each the wall in active section can be actuated independently by signals supplied viaelectrical input 820. Such a break may be achieved e.g. by masking during deposition of the metal plating or by removal of the plating by a laser. - Connection between the electrodes on the channel walls and the
electrical input 820, whilst not shown in detail, may be achieved by any of the known techniques including wire bond between tracks formed in shallow "run-out" grooves formed in thearea 900 rearward of the channel 11 (described in the aforementioned EP-A-0 364 136) or conductive adhesive (e.g. anisotropic conductive adhesive) between conductive tracks formed inarea 900 on the surface of the piezoelectric sheet itself and (described in EP-A-0 397 441). - As in the embodiment of figure 7, each
channel 11 is closed along its two active sections 550,560 by appropriate lengths 820,830 of acover component 500 which is also formed with ports 520,522,540 that allow ink to be supplied to each channel active section and, optionally, allow ink to be circulated through each channel section for cleaning purposes, as is generally known. Ports may be positioned so as to define the edge of an active section, as in the case ofport 522, in which case manufacture is simplified. In the example shown, the width of cover port 552 and thecover closing lengths 820, 803 are of the same order of magnitude, typically 2mm. - Ink ejection from each active section is again via openings that communicate the channel with the opposite surface of the piezoelectric component (sheet 860) to that in which the channel is formed. In the present embodiment, these openings take the form of slots 840,850 which extend some distance - typically 200µm - in the longitudinal direction of the channel so as to allow some leeway in the placing of the respective nozzles 870,880 in
nozzle plate 890. Offsetting of nozzles is generally necessary whenever simultaneous droplet ejection from adjacent channels is not possible e.g. in "shared wall" printheads of the kind illustrated, is generally known e.g. from EP-A-0 376, and will not therefore be discussed in any greater detail. - Printheads according to the present invention may also be made in a modular format as described in the aforementioned WO91/17051, each module being formed in opposite end surfaces thereof with respective channel parts so that, upon butting together of modules, further channels are formed between respective pairs of butted modules. In such arrangements, the respective channel parts may include at least part of a slot formed in the channel base and of sufficient length that, even if a pair of butted modules and their respective slot parts are not perfectly aligned, there remains an overlap between the two slot halves sufficient to accommodate a nozzle.
- As in the previous embodiment, nozzles 870,880 are formed in a
nozzle plate 890 which, as illustrated, may extend over the substantially the entire length ofpiezoelectric sheet 860 so as to provide a suitably large area for engagement e.g. of a capping and/or wiping mechanism. - It should be understood that this invention has been described by way of examples only and that a wide variety of modifications can be made without departing from the scope of the invention. Features shown in the context of the first aspect of the invention may be equally applicable to the second aspect and vice versa.
- The piezoelectric channel walls, for example, can be polarised in opposite directions normal to the plane of the channel axes as known, for example, from EP-A-0 277 703 incorporated herein by reference. Alternatively, polarisation of the channel walls can be parallel to the plane of the channel axes with electrodes formed in the channel walls themselves as known, for example, from EP-A-0 528 647.
- Nor is every channel in a printhead required to be capable of droplet ejection: active channels capable of droplet ejection may be alternated in the printhead with inactive - so-called "dummy" channels - as described, for example, in the aforementioned EP-A-0 277 703.
Claims (14)
- Droplet deposition apparatus comprising:at least one longitudinal, open-topped droplet liquid channel defined by facing longitudinal side walls and a bottom, longitudinal surface extending between the side walls;means for supplying droplet liquid to the channel;means for applying an electric field to piezoelectric material in at least one of said walls, thereby to effect displacement of the wall relative to said longitudinal channel so as to eject a droplet from the channel; anda cover closing the open, longitudinal top side of the channel;
- Apparatus according to claim 1, wherein the means for supplying droplet liquid comprises supply ports in the cover, spaced along the channel so as to lie either side of each opening.
- Apparatus according to claim 1 or claim 2, wherein the piezoelectric material deforms in shear mode when subject to the electric field.
- Apparatus according to any of claims 1 to 3, wherein an electrode is formed on a channel-facing surface of the channel wall.
- Apparatus according to claim 4, wherein an electrode is also formed on the channel wall on a surface opposed to the channel-facing surface of the channel wall.
- Apparatus according to any of claims 1 to 5, wherein said channel wall is displaceable in response to electrical signals in a direction transverse to the axes of the channels.
- Apparatus according to any of claims 1 to 6, wherein said bottom, longitudinal surface is defined by a base, said base and said longitudinal side walls being integral.
- Apparatus according to any of claims 1 to 6 and including a plurality of longitudinal channels arranged parallel to one another.
- Method of manufacture of droplet deposition apparatus comprising the steps of:providing a body including piezoelectric material and having at least one longitudinal, open-topped droplet liquid channel, the channel being defined by facing longitudinal side walls and a bottom, longitudinal surface extending between the side walls;forming in the bottom longitudinal surface of the channel two openings for ejection of droplet liquid, the openings being spaced along the channel;providing means for applying an electric field to piezoelectric material in at least one of said walls, thereby to effect displacement of the wall relative to said longitudinal channel so as to eject a droplet from the channel; andclosing the open, longitudinal top side of the channel by means of a cover.
- Method according to claim 9 comprising the step of closing the open longitudinal top side of the channel by means of a cover incorporating droplet supply ports spaced along the channel so as to lie either side of each opening.
- Method according to claim 9 or claim 10 comprising the step of forming said bottom, longitudinal surface and said longitudinal side walls so as to be integral with one another.
- Method according to claim 11 comprising the steps of providing a body of piezoelectric material and removing material from said body, thereby to form said channel in said body.
- Method according to claim 9 comprising the steps of
providing a body in the form of a sheet having first and second opposite surface;
removing material from the first surface of said body, thereby to form the channel;
forming said two openings in the bottom longitudinal surface of the channel, the openings communicating with said second surface of the sheet. - Method according to claim 13 comprising the step of polarising the piezoelectric material of the sheet in a direction perpendicular to said first and second surfaces.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GBGB9721555.2A GB9721555D0 (en) | 1997-10-10 | 1997-10-10 | Droplet deposition apparatus and methods of manufacture thereof |
GB9721555 | 1997-10-10 | ||
EP98946612A EP1021302B1 (en) | 1997-10-10 | 1998-10-09 | Droplet deposition apparatus and methods of manufacture thereof |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP98946612A Division EP1021302B1 (en) | 1997-10-10 | 1998-10-09 | Droplet deposition apparatus and methods of manufacture thereof |
Publications (2)
Publication Number | Publication Date |
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EP1241007A1 true EP1241007A1 (en) | 2002-09-18 |
EP1241007B1 EP1241007B1 (en) | 2006-03-29 |
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ID=10820385
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Application Number | Title | Priority Date | Filing Date |
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EP98946612A Expired - Lifetime EP1021302B1 (en) | 1997-10-10 | 1998-10-09 | Droplet deposition apparatus and methods of manufacture thereof |
EP02010145A Expired - Lifetime EP1241007B1 (en) | 1997-10-10 | 1998-10-09 | Droplet deposition apparatus and methods of manufacture thereof |
Family Applications Before (1)
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EP98946612A Expired - Lifetime EP1021302B1 (en) | 1997-10-10 | 1998-10-09 | Droplet deposition apparatus and methods of manufacture thereof |
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EP (2) | EP1021302B1 (en) |
JP (1) | JP2001519264A (en) |
KR (1) | KR100567262B1 (en) |
CN (1) | CN1146501C (en) |
AT (1) | ATE231073T1 (en) |
AU (1) | AU747616B2 (en) |
BR (1) | BR9812580A (en) |
CA (1) | CA2301819C (en) |
DE (2) | DE69833978T2 (en) |
ES (2) | ES2186231T3 (en) |
GB (1) | GB9721555D0 (en) |
IL (1) | IL134657A (en) |
WO (1) | WO1999019147A1 (en) |
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GB9828476D0 (en) | 1998-12-24 | 1999-02-17 | Xaar Technology Ltd | Apparatus for depositing droplets of fluid |
GB0000368D0 (en) * | 2000-01-07 | 2000-03-01 | Xaar Technology Ltd | Droplet deposition apparatus |
JP2001334664A (en) * | 2000-05-25 | 2001-12-04 | Seiko Instruments Inc | Head chip and head unit |
CN100528569C (en) * | 2003-08-08 | 2009-08-19 | 柯尼卡美能达控股株式会社 | Liquid jetting device, liquid jetting method, and method of forming wiring pattern on circuit board |
JP2008213434A (en) * | 2007-03-08 | 2008-09-18 | Fuji Xerox Co Ltd | Droplet ejection head, droplet ejection device, and image forming device |
JP5298685B2 (en) * | 2008-07-28 | 2013-09-25 | コニカミノルタ株式会社 | Inkjet head |
JP5437773B2 (en) * | 2009-10-29 | 2014-03-12 | エスアイアイ・プリンテック株式会社 | Liquid ejecting head, liquid ejecting apparatus, and method of manufacturing liquid ejecting head |
JP6322369B2 (en) * | 2013-07-18 | 2018-05-09 | エスアイアイ・プリンテック株式会社 | Liquid ejecting head, liquid ejecting apparatus, and method of manufacturing liquid ejecting head |
GB2522563B (en) | 2013-11-26 | 2015-11-04 | Xaar Technology Ltd | Droplet deposition apparatus and method for manufacturing the same |
US9421768B2 (en) | 2014-04-02 | 2016-08-23 | Kabushiki Kaisha Toshiba | Inkjet printer head |
JP6266460B2 (en) | 2014-07-30 | 2018-01-24 | 株式会社東芝 | Inkjet head and inkjet recording apparatus |
JP6950210B2 (en) | 2017-03-15 | 2021-10-13 | ブラザー工業株式会社 | Liquid discharge head |
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GB8824014D0 (en) * | 1988-10-13 | 1988-11-23 | Am Int | High density multi-channel array electrically pulsed droplet deposition apparatus |
GB9010289D0 (en) * | 1990-05-08 | 1990-06-27 | Xaar Ltd | Drop-on-demand printing apparatus and method of manufacture |
JPH06502810A (en) * | 1990-12-06 | 1994-03-31 | マークポイント ディベロップメント アクチボラゲット | Configuration of droplet ejector on request |
JP2998764B2 (en) * | 1991-06-13 | 2000-01-11 | セイコーエプソン株式会社 | Ink jet print head, ink supply method, and air bubble removal method |
GB2288765B (en) * | 1992-02-25 | 1996-05-01 | Citizen Watch Co Ltd | Ink jet head |
US5659346A (en) * | 1994-03-21 | 1997-08-19 | Spectra, Inc. | Simplified ink jet head |
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1997
- 1997-10-10 GB GBGB9721555.2A patent/GB9721555D0/en not_active Ceased
-
1998
- 1998-10-09 DE DE69833978T patent/DE69833978T2/en not_active Expired - Lifetime
- 1998-10-09 EP EP98946612A patent/EP1021302B1/en not_active Expired - Lifetime
- 1998-10-09 JP JP2000515752A patent/JP2001519264A/en active Pending
- 1998-10-09 DE DE69810799T patent/DE69810799T2/en not_active Expired - Lifetime
- 1998-10-09 CA CA002301819A patent/CA2301819C/en not_active Expired - Fee Related
- 1998-10-09 CN CNB988099640A patent/CN1146501C/en not_active Expired - Lifetime
- 1998-10-09 EP EP02010145A patent/EP1241007B1/en not_active Expired - Lifetime
- 1998-10-09 AT AT98946612T patent/ATE231073T1/en not_active IP Right Cessation
- 1998-10-09 ES ES98946612T patent/ES2186231T3/en not_active Expired - Lifetime
- 1998-10-09 WO PCT/GB1998/003050 patent/WO1999019147A1/en active IP Right Grant
- 1998-10-09 ES ES02010145T patent/ES2257481T3/en not_active Expired - Lifetime
- 1998-10-09 AU AU93608/98A patent/AU747616B2/en not_active Ceased
- 1998-10-09 BR BR9812580-0A patent/BR9812580A/en not_active IP Right Cessation
- 1998-10-09 KR KR1020007003872A patent/KR100567262B1/en not_active IP Right Cessation
- 1998-10-09 IL IL13465798A patent/IL134657A/en not_active IP Right Cessation
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DE3917434A1 (en) * | 1989-05-29 | 1989-11-09 | Siemens Ag | Multi-layer ink printhead with ink channels which are produced by selective etching |
EP0655334A1 (en) * | 1990-02-23 | 1995-05-31 | Seiko Epson Corporation | Drop-on-demand ink-jet printing head |
EP0767061A2 (en) * | 1995-10-06 | 1997-04-09 | Xerox Corporation | Liquid ink printer for producing high resolution images |
Also Published As
Publication number | Publication date |
---|---|
GB9721555D0 (en) | 1997-12-10 |
KR100567262B1 (en) | 2006-04-04 |
CN1146501C (en) | 2004-04-21 |
IL134657A0 (en) | 2001-04-30 |
DE69810799T2 (en) | 2003-10-23 |
WO1999019147A1 (en) | 1999-04-22 |
AU9360898A (en) | 1999-05-03 |
CA2301819C (en) | 2007-07-24 |
BR9812580A (en) | 2002-09-24 |
JP2001519264A (en) | 2001-10-23 |
AU747616B2 (en) | 2002-05-16 |
ES2257481T3 (en) | 2006-08-01 |
ATE231073T1 (en) | 2003-02-15 |
DE69810799D1 (en) | 2003-02-20 |
EP1021302A1 (en) | 2000-07-26 |
ES2186231T3 (en) | 2003-05-01 |
KR20010031048A (en) | 2001-04-16 |
CN1274316A (en) | 2000-11-22 |
DE69833978D1 (en) | 2006-05-18 |
EP1241007B1 (en) | 2006-03-29 |
IL134657A (en) | 2004-01-04 |
CA2301819A1 (en) | 1999-04-22 |
EP1021302B1 (en) | 2003-01-15 |
DE69833978T2 (en) | 2007-01-25 |
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