[go: up one dir, main page]

EP0560760B1 - Systeme d'ejection sur demande de gouttelettes de liquide - Google Patents

Systeme d'ejection sur demande de gouttelettes de liquide Download PDF

Info

Publication number
EP0560760B1
EP0560760B1 EP90917446A EP90917446A EP0560760B1 EP 0560760 B1 EP0560760 B1 EP 0560760B1 EP 90917446 A EP90917446 A EP 90917446A EP 90917446 A EP90917446 A EP 90917446A EP 0560760 B1 EP0560760 B1 EP 0560760B1
Authority
EP
European Patent Office
Prior art keywords
ejector
channel
channels
wafer
nozzle
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.)
Expired - Lifetime
Application number
EP90917446A
Other languages
German (de)
English (en)
Other versions
EP0560760A1 (fr
Inventor
Ove Andersson
Stig-Göran LARSSON
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.)
Markpoint Development AB
Original Assignee
Markpoint Development AB
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 Markpoint Development AB filed Critical Markpoint Development AB
Publication of EP0560760A1 publication Critical patent/EP0560760A1/fr
Application granted granted Critical
Publication of EP0560760B1 publication Critical patent/EP0560760B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/16—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
    • B41J2/1632—Manufacturing processes machining
    • 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
    • B41J2002/14379—Edge 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
    • 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
    • B41J2202/11—Embodiments of or processes related to ink-jet heads characterised by specific geometrical characteristics

Definitions

  • the present invention relates to a drop-on-demand liquid ejector arrangement according to the preamble of claim 1 and to a method of manufacturing such an ejector arrangement according to the preamble of claim 15.
  • the invention is particularly suited for use in ink-jet printing devices.
  • a plurality of droplet ejectors are arranged in a print head so that strings of text or other patterns can be deposited on a recording medium passing in front of the ejectors.
  • Such droplet ejectors have a nozzle which communicates with a fluid chamber fed from a reservoir.
  • a piezoelectric transducer acts on said chamber to rapidly vary the pressure therein and, as a consequence, the volume thereof in response to signals in the form of electrical pulses, whereby fluid droplets, whose velocity and volume depend on the electrical energy of the applied pulses, are ejected from the nozzle.
  • the outlets of the droplet ejectors are arranged in a straight line perpendicular to the recording direction, as described in US-A-3 946 398 to Kyser et al.
  • the nozzles of the droplet ejectors accordingly have to be spaced closer together and it is the size of the transducer and its arrangement which limits the possibilities to closely arrange the nozzles in a straight line perpendicular to the recording direction.
  • the fluid chamber and associated piezoelectric transducer of each droplet ejector can be connected to its nozzle by a conduit, with the conduits of all the ejectors fanning towards their respective nozzles arranged in a straight line.
  • a radial array of such an assembly is described in US-A-3 747 120 to Stemme whilst a substantially longitudinal array is described in US-A-4 158 847 to Heinzl et al.
  • Arrays of this type suffer from the disadvantage that the ejectors require long conduits which affect the control of the droplets.
  • the conduits are of differing lengths which impart non-uniform characteristics to the droplets.
  • a linear array is disclosed in US-A-4 459 601 to Howkins in which the nozzles lie along a line which slopes with respect to the recording direction.
  • the droplets are ejected with an increasing time delay along the array.
  • Such an arrangement has the advantage that it can easily be expanded by adding more ejectors to the array.
  • the need to calculate the required time delay before firing is an expensive complication.
  • a multi-channel droplet ejector, or piezoelectric pump has been proposed in which a piezo wafer has grooves or channels sawn in from the upper side and the under side.
  • the grooves which extend through the entire length of the wafer, lie offset relative to one another and their depths partially overlap.
  • the piezo wafer is metallized over its entire surface, though the metal layer in the channels on one side of the wafer is removed.
  • the discrete layers of metal on this side form individual electrodes for each channel, whilst the layer of metal on the other side serves as a common electrode for all the channels.
  • the region of piezoelectric material between each individual electrode and the common electrode serves as a transducer for each pump channel.
  • a pump allows 4-5 channels per millimetre to be formed in the wafer. Due to the extremely small structures, by blocking off a region of a opening to each pump channel, the remaining open area can itself serve as a nozzle.
  • a multi-channel droplet ejector of the type disclosed in US-A-4 842 493 which comprises a piezoceramic wafer 10 into which grooves 11,12 have been sawn from the upper side and lower side.
  • the grooves 11 serve as pump channels when an electrical pulse is applied to electrodes formed on the upper and lower surfaces of the wafer.
  • a cover plate 14 comprising a projection 15 is placed on the wafer so that the channels' openings are partially blocked, thereby forming the nozzles.
  • the cover plate 14 is also provided with a channel 16 which extends transversely relative to the pump channels and via which all channels can be connected to a fluid reservoir.
  • the channels may also be blocked off at the rear openings by inserts.
  • the above-described pump can be made to function reasonably well, high precision is required for obtaining an accurate fit and good sealing of the projection 15 with the ground-off region, as well as for the individual blocking inserts.
  • the cover plate 14 needs to be machined to form the fluid supply channel 16. Since this channel 16 feeds the pump channels 11 transversely with no restrictor means across the openings into the pump channels, it will serve as a passage for undesired coupling between pump channels. Also there is no means for restricting flow backwards during pump action.
  • FIG. 3 An embodiment of a droplet ejector arrangement according to the present invention is shown in Fig. 3.
  • Reference numeral 20 denotes a piezoceramic wafer with ejector channels 21 on one side 22 and corresponding separation grooves 23 on the other side 24. For reasons of clarity, a cover plate has not been shown. Whilst the term "piezoceramic" has been used herein, it is to be understood that any material possessing piezoelectric properties may be used.
  • the ejector channels 21 do not extend throughout the entire length of the ceramic wafer 20. Instead, the channels 21 are formed by, for example, a circular diamond saw blade SB whose centre follows the locus of points indicated by the letters LP in Fig. 4.
  • the channels, as well as the separation grooves, may of course be formed by other means, such as milling, moulding, pressing, grinding or cutting in any way.
  • the nozzle 25 is a part of the ejector channel 21 and may be formed by removing a slight amount of piezoceramic material.
  • the length of the nozzle section is determined in this instance by the length of pass of the circular saw along the wafer 20 at that depth.
  • the pumping region of the channel is formed by lowering the saw blade deeper into the material. In this respect, it is often advantageous to form a flat region along the base of the channel.
  • a restrictor 26 can also be formed as a part of the channel in the wafer by raising the saw to a suitable height then progressing horizontally through the wafer.
  • the restrictor 26 connects the remainder of the channel 21 with a transverse, fluid supply conduit 27 which serves as a manifold and to which fluid from a not-shown reservoir is fed.
  • the width of the nozzle, and of course the restrictor, can be varied with respect to the pumping region of the channel by, in this case, using a narrower saw blade.
  • the separation grooves 23 adjacent to the ejector channels 21 are shown in Fig. 3 as extending from the front surface of the wafer 20. Naturally, to prevent these grooves 23 breaking through into the fluid supply conduit 27, the grooves 23 terminate a little way before the said conduit 27.
  • a gas preferably air
  • the gas can be used to help form and control the droplets emerging from the nozzles 25 of the ejector channels 21. Such an arrangement is commonly referred to as "air-assistance".
  • the grooves 23 may have a similar trough-like form to the ejector channels 21.
  • the transducer and essentially all (or most) of the fluidic channels are located in a single piece of piezoelectric ceramics.
  • the layout is such that transducer and groove parameters can be selected more or less independently to optimize the characteristics of the ejector.
  • the cross section along the ejector channel from the fluid supply conduit up to the nozzle can be varied in such a way as to achieve a streamlined flow-through design in order to avoid air entrapment.
  • a restriction inbetween the fluid supply conduit and the ejector channel can be arranged not only to optimize the ejector characteristics, but also to prevent fluidic coupling to other ejectors in the same ceramic piece.
  • the channels can be covered by a thin planar sheet of ceramics, glass, metal or similar which requires no projections thereon or recesses therein.
  • This embodiment closely corresponds to that shown in Figs. 3 and 4, and so the same figure reference numerals have been used where possible, though with the suffix " ' ".
  • the side walls of the ejector channels 21' and the separation grooves 23' are oblique.
  • the width of each channel and groove is greatest at its respective planar surface 22', 24'.
  • the nozzle 25' may be narrower than the width of the ejector channel 21' at the region where the nozzle opens into said channel.
  • the position of the nozzle can be varied with respect to the ejector channel by forming the nozzle in a part distinct from the wafer, as shown in Figures 7 to 10.
  • a plurality of ejector channels 31 are formed in a wafer 30.
  • the ejector channels 31 extend up to, and partially through, the front surface of the wafer. Adjacent to this surface is positioned an end-plate 32 with at least one nozzle 33 cooperating with each ejector channel 31. With such an arrangement, the location of the nozzle 33 with respect to the ejector channel, as well as its shape and size, can be varied.
  • a wafer 40 is shown with a cover plate 42 lying over ejector channels 41 and the fluid supply conduit 45.
  • the ejector channels 41 are formed so that no break-through occurs in the front surface of the wafer.
  • a cavity 43 is provided above each channel in a cover plate 42.
  • a nozzle 44 leads from the cavity to the surroundings.
  • nozzle 44 is shown exiting in the same longitudinal direction as the ejector channel 41, it is of course feasible that the nozzle exits in a direction more or less perpendicular to that shown, i.e. through the upper surface of the cover plate 42 .
  • a direction more or less perpendicular to that shown i.e. through the upper surface of the cover plate 42 .
  • Such an arrangement is shown in Fig. 9. In this instance, no cavity is required and the nozzle 44 can extend through the entire thickness of the cover plate 42.
  • the angle of exit of the nozzle 44 need not necessarily be a right-angle, but may be inclined as required.
  • FIG. 10 A modification of the embodiment according to Fig. 9 is shown in Fig. 10.
  • two fluid supply conduits 45' for each ejector channel are formed in the piezo wafer 40', one at either end of the channel 41'.
  • the nozzle 44', or nozzles, of each ejector channel may be arranged in the cover plate 42' at any location along the longitudinal axis of the channel.
  • a further embodiment is shown in Fig. 11.
  • the assembly has been shown inverted with respect to the previous figures. This is to emphasize that the orientation of the assembly is not important for the present invention.
  • a wafer 50 is provided with a plurality of ejector channels 51.
  • a cover plate 52 is positioned adjacent the wafer 50 as shown, with a nozzle 53 for each ejector channel being provided in the wafer in a manner similar to that shown in Fig.4.
  • the position of a restrictor can be varied with respect to the ejector channels, especially when it is made up of a plurality of micro-channels, by forming the restrictor in a part distinct from the wafer.
  • a through-bore 54 which serves as a fluid supply conduit, is provided in the cover plate 52, and the restrictor is in the form of a microfilter 55, schematically shown in Fig. 11 covering the through-bore 54.
  • Microfilters can of course be used with any of the embodiments described herein.
  • a droplet ejector arrangement is shown in which a pair of ejector channels 61 on one side 62 of the piezo wafer 60 are non-parallel and meet in the vicinity of their nozzles 65 to form a common nozzle in the front face of the wafer.
  • a pair of ejector channels 61 on one side 62 of the piezo wafer 60 are non-parallel and meet in the vicinity of their nozzles 65 to form a common nozzle in the front face of the wafer.
  • more than one pair of ejector channels may be provided and it is feasible to have more than two ejector channels which converge together.
  • Separation grooves 63 are provided on the other side 64 of the wafer. Although not shown in the drawing, at least one separation groove 63 also lies between the ejector channels 61.
  • each nozzle may penetrate the front face of the wafer 60 such that the droplets emerging from said nozzles 65 meet at a point remote from said wafer.
  • a greater ejector channel density than that attainable with the droplet ejectors described above is desirable.
  • greater channel density is obtained by providing a piezoceramic wafer of the type shown for example in Fig. 4 on either side of a separation plate, as shown in Fig. 13.
  • the channel density is thus hereby effectively doubled.
  • Another possibility is to operate the separation grooves as additional ejector channels.
  • the wafers 20 are positioned on the separation plate 28 such that the nozzles 25 in one wafer are offset from the nozzles in the other wafer.
  • the separation distance S between the sets of nozzles is governed by the thickness of the separation plate 28.
  • the separation plate 28 may be provided with a cavity and a nozzle for each ejector channel 21, similar to that shown in Fig. 8, but with cavities opening into the ejector channels in both wafers.
  • the separation plate 28 can be totally excluded, with the wafers 20 being directly affixed to each other.
  • the nozzles then being substantially linearly arranged, a further advantage is obtained, that being that a common liquid supply conduit may be used.
  • Another possibility for varying the arrangement of nozzles with respect to eachother is to provide at least two longitudinally coaxially arranged ejector channels in the one face of a piezo wafer. Such a possibility is shown in Figs. 14, 15, and 16.
  • the two longitudinally coaxially arranged ejector channels 71 are formed in a piezo wafer 70 and are in communication with one another. Fluid is supplied to the ejector channels 71 via three fluid supply conduits 75 extending transversely to the longitudinal axis of the channels 71. One of said supply conduits is arranged between the two ejector channels and serves as a common fluid supply conduit, whilst the remaining two supply conduits are in communication with the opposite end of each respective ejector channel 71.
  • droplets are ejected via nozzles 74 provided at desired locations in a cover plate 72 which delimits the longitudinal opening of each ejector channel.
  • the ejector channels 71' are discrete, i.e. no common fluid supply conduit is provided. Instead, there is one fluid supply conduit 75' for each ejector channel 71'.
  • the said supply conduits 75' feed the left-hand end of the ejector channels 71', as drawn, whilst in Fig. 16 the ends of the channels 71' lying furthest away from eachother are fed.
  • nozzles 74' for the ejector channels 71' are provided in a cover plate 72'.
  • the arrangements according to Figs. 15 and 16 have the advantage that a different fluid can be provided in each supply conduit 75', thereby permitting for example a multicoloured image to be generated.
  • a plurality of grooves are formed on both sides of a non-polarized piezoceramic wafer as described above in connection with Figures 3 and 4.
  • a wafer may typically be made from standard piezoceramic material in the approximate form of a cuboid having the dimensions 30 x 20 x 1 mm .
  • a circular saw blade is utilized to form the grooves, since all the grooves on one side of the wafer are identical, a plurality of such blades may be connected together for simultaneous cutting of the grooves.
  • the cutters are numerically controlled by a microprocessor or similar to which parameters for the desired width, depth and length for each groove, nozzle and restrictor have been inputted.
  • the characteristics of the droplet ejector can be easily altered.
  • the grooves are formed by, say, moulding or pressing, then it is the moulds or presses which are machined in a numerically controlled manner in order to create grooves of the desired shape and size.
  • the entire surface of the piezoceramic wafer is coated with a conductive material in order to form electrodes for the ejector channels. If it is desired to have a fluid supply conduit within the wafer, this can be formed either before coating of the wafer or afterwards.
  • the coating should preferably have the following advantages; it should be conductive, chemically resistant to various liquids and particularly inks, easy to bond to and have good adherence to ceramics.
  • the wafer can be coated in several ways, though the preferred method in this instance is to use chemical vapour deposition (CVD) of silicon.
  • CVD can provide a chemically resistant, thin layer with a very accurate control of the thickness, and the silicon is receptive to doping to enhance the conductivity.
  • Such a formed coating can also be bonded extremely well to several materials.
  • Coating methods other than CVD which may be used include nickel plating, gold sputtering, plasma vapour deposition, etc.
  • the electrode layer at the floor of the separation grooves and on the front and rear faces of the wafer is removed.
  • the electrode layer on the surface in which the ejector channels are formed acts as a common electrode for all the ejector channels.
  • discrete electrodes can be formed by masking those areas on which no coating is required.
  • the transducer for each ejector channel formed in the piezoceramic wafer is polarized by applying a voltage between its electrodes.
  • the present invention offers flexibility of design of droplet ejectors which, up until now, has not been available. Since the cross-sectional area of the ejector channels can be varied along its length, the channels can be optimized for each application.
  • droplet ejector according to the present invention may be operated on the so-called fire-before-fill or the fill-before-fire principle.
  • the present invention is not restricted to the above described embodiments, but may be varied within the scope of the appended claims.
  • more than one nozzle can be provided for each ejector channel.
  • more than one restrictor passage can also be provided for each channel.
  • planar faces of the wafer need not be parallel as shown in the drawings, but can also slope so as to form a wedge-shaped wafer.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Particle Formation And Scattering Control In Inkjet Printers (AREA)

Abstract

Système éjecteur de gouttlettes destiné notamment à une imprimante à jet d'encre et formé dans au moins une tranche piézoélectrique, de préférence en céramique piézoélectrique (20). Des rainures sont ménagées dans une face de la tranche et servent de canaux d'éjection (21) dont chacun possède un bec (25). Pendant la fabrication, on peut déterminer les caractéristiques du système éjecteur de gouttelettes, c'est-à-dire la taille, la vitesse d'éjection et le débit des gouttelettes sortant des canaux, en sélectionnant de manière appropriée la longueur, la profondeur et la largeur desdits canaux (21) ainsi que la longueur, la profondeur et la largeur des becs (25). On peut optimiser les caractéristiques de l'écoulement du liquide en faisant varier la superficie de la section desdits canaux (21).

Claims (20)

  1. Ensemble de projection de gouttelettes, comprenant au moins une tranche piézoélectrique, de préférence piézocéramique (20, 30, 40, 50, 60, 70) ayant une première et une seconde face planes et opposées (22, 22', 62 ; 24, 24', 64) ayant au moins une gorge longitudinale (21, 21', 23, 23', 31, 41, 41', 51, 61, 63, 71, 71') tournée vers l'intérieur, afin que la gorge ou les gorges de la première face soient décalées par rapport à la gorge ou les gorges de la seconde face, les gorges se recouvrant partiellement dans la direction de leur profondeur, la première et la seconde face ayant chacune un revêtement conducteur, le revêtement de la seconde face étant supprimé du fond de la gorge ou des gorges à cette face afin qu'un espace isolant soit formé à son niveau, chaque gorge (21, 21', 31, 41, 41', 51, 61, 71, 71') de la première face (22, 22', 62) formant un canal de projection alimenté en liquide et ayant une buse (25, 25', 33, 44, 44', 53, 65, 74, 74') à une première extrémité, caractérisé en ce que le liquide est transmis au canal de projection par un rétrécissement (26 ; 55), et en ce que la section le long du canal de projection (21, 21', 31, 41, 41', 51, 61, 71, 71') du rétrécissement vers la buse varie par formation de régions de profondeurs différentes dans le canal, cette profondeur étant mesurée depuis la face dans laquelle pénètre le canal, la région centrale du canal ayant une profondeur maximale, et la buse et le rétrécissement communiquant avec le canal par des régions peu profondes afin qu'un courant convenablement profilé de liquide soit obtenu dans le canal et évite le piégeage d'air.
  2. Ensemble de projection de gouttelettes selon la revendication 1, caractérisé en ce que le rétrécissement (26) est formé dans la tranche à l'extrémité de chaque canal de projection (21, 21', 31, 41, 41', 61, 71, 71') qui est distante de la buse (25, 25', 33, 44, 44', 65, 74, 74').
  3. Ensemble de projection de gouttelettes selon la revendication 2, caractérisé en ce que le liquide est transmis au rétrécissement (26) par un conduit d'alimentation en fluide (27, 45, 45', 75, 75') qui est placé vers l'intérieur depuis la même face (22, 22', 62) que le canal ou les canaux de projection (21, 31, 41, 41', 61, 71, 71').
  4. Ensemble de projection de gouttelettes selon la revendication 2 ou 3, caractérisé en ce que la buse (25, 25', 53, 65) de chaque canal de projection est un prolongement du canal de projection et est formée afin qu'elle soit solidaire dans la tranche (20, 50, 60) jusqu'à une profondeur inférieure à la profondeur maximale du canal (21, 21', 51, 61).
  5. Ensemble de projection de gouttelettes selon la revendication 2 ou 3, caractérisé en ce que chaque buse (33) est formée dans une plaque d'extrémité (32) qui délimite l'extrémité du canal distante du rétrécissement.
  6. Ensemble de projection de gouttelettes selon la revendication 2 ou 3, caractérisé en ce que chaque buse (44, 44') est formée dans une plaque de couvercle (42, 42') qui délimite l'ouverture longitudinale de chaque canal de projection (41, 41').
  7. Ensemble de projection de gouttelettes selon la revendication 1, caractérisé en ce que le liquide est transmis au canal de projection (51) par au moins un trou (54) formé dans une plaque de couverture (52).
  8. Ensemble de projection de gouttelettes selon les revendications 1 et 6, caractérisé en ce que la buse (44') de la plaque formant couvercle (42') est placée en partie le long du canal de projection, et le liquide est transmis au canal de projection (41') par deux conduits (45') d'alimentation en liquide, un conduit étant placé à chaque extrémité du canal (41').
  9. Ensemble de projection de gouttelettes selon la revendication 6, caractérisé en ce que deux canaux de projection au moins (71, 71') sont disposés coaxialement en direction longitudinale à la première face.
  10. Ensemble de projection de gouttelettes selon l'une quelconque des revendications 1 à 6, caractérisé en ce que deux tranches piézoélectriques (20) sont disposées afin que les faces des tranches ayant les canaux de projection (21) soient placées l'une au-dessus de l'autre et tournées l'une vers l'autre, les canaux de projection (21) d'une tranche étant décalés par rapport aux canaux respectifs de projection (21) de l'autre tranche.
  11. Ensemble de projection de gouttelettes selon la revendication 10, caractérisé en ce qu'une plaque de séparation (28) est placée entre les deux tranches (20).
  12. Ensemble de projection de gouttelettes selon la revendication 11, caractérisé en ce que les buses (25) des canaux de projection (21) sont disposées dans la plaque de séparation (28).
  13. Ensemble de projection de gouttelettes selon l'une quelconque des revendications précédentes, caractérisé en ce que plusieurs canaux de projection (61) sont formés à la première face (62), et des paires de canaux au moins ne sont pas parallèles et convergent vers leurs extrémités ayant les buses.
  14. Ensemble de projection de gouttelettes selon l'une quelconque des revendications précédentes, caractérisé en ce que le canal de projection (21, 21', 31, 41, 41', 51, 61, 71, 71') a une région plate le long de sa base.
  15. Procédé de fabrication d'un ensemble de projection de gouttelettes selon l'une quelconque des revendications 1 à 14, le procédé comprenant :
    1) la formation d'au moins une gorge longitudinale destinée à être utilisée comme canal de projection pour un liquide dans une première face plane d'une tranche piézoélectrique, de préférence piézocéramique, des régions de cette tranche étant utilisées comme transducteurs pour le canal de projection et, lorsque plusieurs gorges sont formées dans la première face, la formation de gorges dans une seconde face plane de la tranche opposée à la première face, afin que ces dernières gorges soient décalées par rapport aux canaux de projection de la première face et recouvrent partiellement ceux-ci dans la direction de leur profondeur, le canal ou les canaux de projection ayant une buse ou des buses à une première extrémité,
    2) le revêtement de toute la surface de la tranche d'un matériau conducteur pour la formation d'une couche conductrice,
    3) l'enlèvement de régions de la couche conductrice à la base de la gorge ou des gorges formées à l'autre face de la tranche et aux faces avant et arrière de la tranche, et
    4) la polarisation de chaque transducteur par application d'une impulsion de tension entre ses électrodes,
    caractérisé par la formation des gorges dans la tranche par utilisation d'un dispositif sous la commande d'un microprocesseur ou un dispositif analogue, ayant des paramètres prédéterminés de longueur, de profondeur et de largeur pour toutes les gorges, transmis pour la création de régions de section variable le long du canal ou des canaux de projection, d'un rétrécissement vers la buse ou vers les buses, la région centrale du canal ayant une profondeur maximale et la buse et le rétrécissement communiquant avec le canal dans des régions peu profondes afin qu'un ensemble de projection de gouttelettes soit formé et qu'il donne un écoulement profilé du liquide dans le canal et évite ainsi le piégeage d'air.
  16. Procédé de fabrication d'un ensemble de projection de gouttelettes selon la revendication 15, caractérisé en ce que, lorsqu'un seul canal de projection est formé dans la première face plane, une gorge au moins est formée dans la seconde face en direction pratiquement parallèle au canal de projection mais décalée par rapport à celui-ci.
  17. Procédé de fabrication d'un ensemble de projection de gouttelettes selon la revendication 15 ou 16, caractérisé en ce que la profondeur d'introduction de l'élément utilisé pour la formation du canal ou des canaux varie sur la longueur du canal ou des canaux de manière que la section des régions du canal ou des canaux de projection varie.
  18. Procédé de fabrication d'un ensemble de projection de gouttelettes selon l'une quelconque des revendications 15 à 17, caractérisé par l'enlèvement ou la formation d'un matériau piézoélectrique sur une profondeur qui est inférieure à la profondeur maximale du canal de projection à une première extrémité du canal pour la formation de la buse destinée à chaque canal de projection et/ou par enlèvement ou formation de matière à une moindre profondeur que la profondeur maximale du canal de projection à l'autre extrémité pour la réalisation du rétrécissement destiné à chaque canal de projection.
  19. Procédé de fabrication d'un ensemble de projection de gouttelettes selon les revendications 15 à 17, caractérisé par l'enlèvement ou la formation d'un matériau à une profondeur inférieure à la profondeur maximale du canal de projection aux deux extrémités du canal pour la réalisation d'un rétrécissement aux deux extrémités de ce canal, chaque rétrécissement communiquant avec une source de liquide, la buse de ce canal étant formée dans une plaque constituant un couvercle qui délimite l'ouverture longitudinale du canal.
  20. Procédé de fabrication d'un ensemble de projection de gouttelettes selon l'une quelconque des revendications 15 à 19, caractérisé en ce que le revêtement est réalisé par dépôt chimique en phase vapeur et la conductivité dans les régions voulues est obtenue par dopage.
EP90917446A 1990-12-06 1990-12-06 Systeme d'ejection sur demande de gouttelettes de liquide Expired - Lifetime EP0560760B1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/EP1990/002119 WO1992010367A1 (fr) 1990-12-06 1990-12-06 Systeme d'ejection sur demande de gouttelettes de liquide

Publications (2)

Publication Number Publication Date
EP0560760A1 EP0560760A1 (fr) 1993-09-22
EP0560760B1 true EP0560760B1 (fr) 1994-08-17

Family

ID=8165541

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90917446A Expired - Lifetime EP0560760B1 (fr) 1990-12-06 1990-12-06 Systeme d'ejection sur demande de gouttelettes de liquide

Country Status (4)

Country Link
EP (1) EP0560760B1 (fr)
JP (1) JPH06502810A (fr)
DE (1) DE69011694T2 (fr)
WO (1) WO1992010367A1 (fr)

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0596739A (ja) * 1991-10-09 1993-04-20 Rohm Co Ltd インクジエツトプリントヘツドの製造方法
SE9200555D0 (sv) * 1992-02-25 1992-02-25 Markpoint Dev Ab A method of coating a piezoelectric substrate
GB9400036D0 (en) * 1994-01-04 1994-03-02 Xaar Ltd Manufacture of ink jet printheads
JPH08336966A (ja) * 1995-06-15 1996-12-24 Minolta Co Ltd インクジェット記録装置
DE69605641T2 (de) * 1996-02-14 2000-06-08 Oce-Technologies B.V., Venlo Druckkopf für einen Tintenstrahldrucker
NL1004016C2 (nl) * 1996-09-12 1998-03-13 Oce Tech Bv Inktstraal-drukkop.
GB9710530D0 (en) * 1997-05-23 1997-07-16 Xaar Ltd Droplet deposition apparatus and methods of manufacture thereof
JP3666198B2 (ja) * 1997-08-26 2005-06-29 コニカミノルタホールディングス株式会社 インクジェットヘッド
AU8765398A (en) * 1997-08-29 1999-03-22 Topaz Technologies, Inc. Integrated head assembly for an ink jet printer
US6572221B1 (en) 1997-10-10 2003-06-03 Xaar Technology Limited Droplet deposition apparatus for ink jet printhead
GB9721555D0 (en) * 1997-10-10 1997-12-10 Xaar Technology Ltd Droplet deposition apparatus and methods of manufacture thereof
US6074046A (en) * 1998-03-06 2000-06-13 Eastman Kodak Company Printer apparatus capable of varying direction of an ink droplet to be ejected therefrom and method therefor
JP2940544B1 (ja) 1998-04-17 1999-08-25 日本電気株式会社 インクジェット記録ヘッド
JP5354720B2 (ja) * 2008-12-08 2013-11-27 エスアイアイ・プリンテック株式会社 液体噴射ヘッドの製造方法
JP5748474B2 (ja) * 2010-12-22 2015-07-15 キヤノン株式会社 液体吐出ヘッドの製造方法

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0234781B2 (ja) * 1980-03-21 1990-08-06 Seiko Epson Corp Inkujetsutokirokuyohetsudo
DE3645017C2 (fr) * 1985-09-06 1990-07-12 Fuji Electric Co., Ltd., Kawasaki, Kanagawa, Jp
EP0268204B1 (fr) * 1986-11-14 1991-09-18 Qenico AB Pompe piézo-électrique
JPS63312158A (ja) * 1987-06-13 1988-12-20 Fuji Electric Co Ltd インクジェット記録ヘッド
GB8824014D0 (en) * 1988-10-13 1988-11-23 Am Int High density multi-channel array electrically pulsed droplet deposition apparatus

Also Published As

Publication number Publication date
WO1992010367A1 (fr) 1992-06-25
DE69011694D1 (de) 1994-09-22
EP0560760A1 (fr) 1993-09-22
DE69011694T2 (de) 1995-01-26
JPH06502810A (ja) 1994-03-31

Similar Documents

Publication Publication Date Title
EP0560760B1 (fr) Systeme d'ejection sur demande de gouttelettes de liquide
US5605659A (en) Method for poling a ceramic piezoelectric plate
US6450627B1 (en) Simplified ink jet head
JP4644790B2 (ja) 液体噴射装置
US6554408B1 (en) Fluid ejection device and process for the production thereof
US5438739A (en) Method of making an elongated ink jet printhead
US6188416B1 (en) Orifice array for high density ink jet printhead
EP2230081B1 (fr) Tête d'impression à jet d'encre et procédé d'impression l'utilisant
US20090008027A1 (en) Inkjet Printheads
US6481073B1 (en) Method for manufacturing ink jet print head
WO2018084827A1 (fr) Dispositif d'éjection de fluide
KR20060096443A (ko) 액적 침착 장치
US6874869B1 (en) Inkjet printhead
EP1022140B1 (fr) Tête d'impression par jet d'encre
GB2364965A (en) Manufacture of piezoelectric print head
JP4792890B2 (ja) インクジェット式記録ヘッド及びその印刷装置
JPH07117229A (ja) インクジェットヘッド
EP3703954B1 (fr) Dimensions d'orifice de trou d'alimentation en fluide
US6568798B1 (en) Ink-jet print head having ink chambers defined by an entire thickness of a chamber sheet, and method of manufacturing the same
CA2129182C (fr) Tete d'impression a jet d'encre transversal et methode de fabrication de cette tete
JPH02297445A (ja) インクジェットプリンタのインク吐出装置
JP2001010065A (ja) インクジェット式記録ヘッド及びインクジェット式記録装置並びにノズルプレートの製造方法及びインクジェット式記録ヘッドの製造方法
JPH05293959A (ja) インクジェットヘッド
JPH11348274A (ja) インクジェット記録ヘッド
JPH08187851A (ja) インクジェットヘッド

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19930526

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB IT

17Q First examination report despatched

Effective date: 19931210

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT

REF Corresponds to:

Ref document number: 69011694

Country of ref document: DE

Date of ref document: 19940922

ITF It: translation for a ep patent filed
ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19991116

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19991210

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19991217

Year of fee payment: 10

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20001206

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20001206

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20010831

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20011002

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20051206