EP0121894A2 - Piezoelectrically operated write head for ink mosaic recording devices - Google Patents

Piezoelectrically operated write head for ink mosaic recording devices Download PDF

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Publication number
EP0121894A2
EP0121894A2 EP84103655A EP84103655A EP0121894A2 EP 0121894 A2 EP0121894 A2 EP 0121894A2 EP 84103655 A EP84103655 A EP 84103655A EP 84103655 A EP84103655 A EP 84103655A EP 0121894 A2 EP0121894 A2 EP 0121894A2
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EP
European Patent Office
Prior art keywords
ink
writing
ink channels
head according
write head
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Granted
Application number
EP84103655A
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German (de)
French (fr)
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EP0121894A3 (en
EP0121894B1 (en
Inventor
Rolf Roeschlein
Heinz Schulte
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Wincor Nixdorf International GmbH
Nixdorf Computer AG
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Wincor Nixdorf International GmbH
Nixdorf Computer AG
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Publication of EP0121894A2 publication Critical patent/EP0121894A2/en
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Publication of EP0121894B1 publication Critical patent/EP0121894B1/en
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters 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
    • B41J2/01Ink jet
    • B41J2/17Ink jet characterised by ink handling
    • B41J2/175Ink supply systems ; Circuit parts therefor
    • B41J2/17563Ink filters

Definitions

  • the invention relates to a piezoelectrically operated writing head for ink mosaic writing devices with a plurality of writing nozzles in the form of ink channels receiving writing fluid, each of which is enclosed by a piezoelectric drive element and is connected to an ink space common to them via a filter arrangement, the ink channels being of substantially greater length than the drive elements to have.
  • a write head of this type is e.g. B. from DE-PS 25 43 451 known. Its ink channels open with their nozzle openings at the tip of the print head in a grid-like distribution, which makes it possible to record characters on a record carrier with suitable selective activation of the piezoelectric drive elements with electrical voltage pulses in the course of a line-wise movement of the write head.
  • the tubular piezoelectric drive elements as a result of their activation with the voltage pulses, bring about a corresponding pulse-like contraction of the ink channels, by means of the pressure pulses on the ink present in the ink channels are exercised, which in turn lead to the detachment of ink droplets at the nozzle openings of the ink channels and to their transfer to the recording medium.
  • a disadvantage of the previously known writing heads of this type is that the distance between the nozzle openings and the recording medium cannot be increased arbitrarily and in the sense of the most accurate possible mosaic-like creation of characters may not exceed 0.5 to 1 mm.
  • One such application is, for example, the labeling of savings books in banking as part of an automatic booking process.
  • the page to be labeled can have a large or small distance from the print head or its nozzle openings. Within a distance range, which can then be up to 3 mm or more, the writing accuracy should always be constant.
  • the object of the invention is therefore to provide a design for a write head of the type mentioned at the beginning which makes it possible to produce recordings with satisfactory accuracy over larger distances than before, without having to accept impairments in the write accuracy due to excessive control voltage amplitudes.
  • a throttle plate and a close-meshed grating are provided between the ink channels and the ink space common to them as a filter arrangement, which is intended to prevent air from entering the ink space through the ink channels.
  • the throttle plate contains a very narrow through opening for each ink channel, which is intended to reduce pressure peaks in the ink supply system and to ensure a mutual decoupling of the pressure effects of the ink channels from one another.
  • each ink channel has a funnel-shaped extension adjacent to this layer. It has been shown that with this arrangement a considerably better utilization of the energy of the pressure pulses generated with the piezoelectric drive elements is possible, which leads to the fact that the ink droplets emerging at the nozzle openings can fly through a considerably greater distance to the recording medium while maintaining their predetermined path.
  • the filter material has a mesh width of approximately 0.035 mm and a thickness of approximately 0.05 mm. This dimensioning seems to ensure a particularly good capillary action of the filter material for the continuous supply of ink to the individual ink channels, combined with an adequate filter action.
  • Cutouts in the body containing the ink channels can be provided in various ways as funnel-shaped extensions of the ink channels.
  • an embodiment has proven to be particularly advantageous in which the extensions of the ink channels are conical in shape with an opening angle of approximately 60 °.
  • the extensions are again advantageously dimensioned if they have a diameter of approximately 3 mm at their transition to the filter material. This dimension is then in a particularly favorable relationship to the diameter of the ink channels, which is usually in the order of magnitude of 0.5 to 0.7 mm at the mouth of the filter layer.
  • a write head according to the invention is shown schematically in a cross section as an exemplary embodiment.
  • This write head essentially consists of a plastic body 10, which is conical and is incorporated in the ink channels 11, which converge towards the left tip of the body 10 and open there with nozzle openings 12.
  • a record carrier 13 Arranged on which the ink droplets emerging from the nozzle openings 12 can record characters as a result of the mosaic-like distribution of the nozzle openings 12 with relative movement between the body 10 and the recording medium 13.
  • the ink droplets are generated in that tubular piezoelectric drive elements 14, which surround the ink channels 11, are selectively driven in rapid succession with voltage pulses, as a result of which they deform in the manner of a contraction and generate a pressure pulse in the respective ink channel 11, which pulse occurs in the ink channel 11 existing ink affects so that the ink is detached at the nozzle openings 12 and shot onto the recording medium 13.
  • an ink supply system is provided, the reservoir of which is not shown in the figure.
  • the ink is supplied from such a reservoir at 15 to the print head and enters an ink space 16 common to all ink channels, which is formed between the body 10 and a rear end plate 17, which is in sealing connection with the body 10 and e.g. is screwed (not shown).
  • the common ink space 16 is so narrow that the ink supplied at 15 rises through it by capillary action and fills it up as a whole.
  • the width of the ink space 16 can be, for example, 0.1 to 0.3 mm.
  • the ink space 16 is delimited on its left side by a layer 18 of a filter material, which is made, for example, of a fibrous plastic material with a mesh density of 0.035 mm.
  • the thickness of this layer 18 can be approximately 0.05 to 0.3 mm.
  • the individual ink channels 11 are more than twice as long as the drive elements 14 and are connected to the layer 18 of the filter material via a funnel-shaped extension 19, which is conical in the illustrated embodiment.
  • the opening angle of this funnel shape can e.g. Be 60 °.
  • the ink channels 11 can e.g. have a length of 35 mm, while the drive elements 14 are then about 12 mm long.
  • the piezoelectric drive element 14 of an ink channel 11 is driven with an electrical voltage pulse, then a pressure pulse is generated in the ink channel 11 within the ink filling it, which pressure pulse moves in the direction of the nozzle opening 12, but also in the opposite direction, namely to the layer 18 of the filter material there, reproduced.
  • the pressure pulse causes the detachment of an ink droplet at the nozzle opening 12 and its movement towards the recording medium 13.
  • the enlargement 19 and the consequent increase in the flow cross section of the filter material layer 18 results in a higher flow velocity of the ink compared to comparable known writing heads, which means that the recording medium 13 can have a correspondingly greater distance from the nozzle openings 12. In practice it has been shown that this distance can be of the order of 3 mm.
  • the piezoelectric drive elements 14 surround the ink channels 11 in a position that is arranged as close as possible to the extensions 19, while the remaining free length of the ink channels 11 lies in front of the drive elements 14.

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Abstract

Bei einem piezoelektrisch betriebenen Schreibkopf (10) für Tintenmosaikschreibeinrichtungen sind die Tintenkanäle (11) über jeweils eine trichterförmige Erweiterung (19) mit einer Filterschicht (18) verbunden, an die sich unmittelbar ein allen Tintenkanälen (11) gemeinsamer Tintenraum (16) anschließt. Die Erweiterungen (19) erhöhen den Strömungsquerschnitt in der Filterschicht (18) und damit die Strömungsgeschwindigkeit der Tinte.In the case of a piezoelectrically operated write head (10) for ink mosaic writing devices, the ink channels (11) are each connected via a funnel-shaped extension (19) to a filter layer (18), which is immediately adjoined by an ink space (16) that is common to all ink channels (11). The extensions (19) increase the flow cross section in the filter layer (18) and thus the flow speed of the ink.

Description

Die Erfindung betrifft einen piezoelektrisch betriebenen Schreibkopf für Tintenmosaikschreibeinrichtungen mit mehreren Schreibdüsen in Form von Schreibflüssigkeit aufnehmenden Tintenkanälen, die jeweils von einem piezoelektrischen Antriebselement umschlossen sind und über eine Filteranordnung mit einem ihnen gemeinsamen Tintenraum in Verbindung stehen, wobei die Tintenkanäle eine wesentlich größere Länge als die Antriebselemente haben.The invention relates to a piezoelectrically operated writing head for ink mosaic writing devices with a plurality of writing nozzles in the form of ink channels receiving writing fluid, each of which is enclosed by a piezoelectric drive element and is connected to an ink space common to them via a filter arrangement, the ink channels being of substantially greater length than the drive elements to have.

Ein Schreibkopf dieser Art ist z. B. aus der DE-PS 25 43 451 bekannt. Seine Tintenkanäle münden mit ihren Düsenöffnungen an der Schreibkopfspitze in einer rasterartigen Verteilung, durch die es möglich wird, bei geeigneter selektiver Ansteuerung der piezoelektrischen Antriebselemente mit elektrischen Spannungsimpulsen im Verlauf einer zeilenweisen Bewegung des Schreibkopfes auf einen Aufzeichnungsträger Schriftzeichen aufzuzeichnen. Dabei bewirken die röhrchenförmigen piezoelektrischen Antriebselemente infolge ihrer Ansteuerung mit den Spannungsimpulsen eine entsprechend impulsartige Kontraktion der Tintenkanäle, durch die Druckimpulse auf die in den Tintenkanälen vorhandene Tinte ausgeübt werden, welche wiederum zur Ablösung von Tintentröpfchen an den Düsenöffnungen der Tintenkanäle sowie zu deren Übertragung auf den Aufzeichnungsträger führen.A write head of this type is e.g. B. from DE-PS 25 43 451 known. Its ink channels open with their nozzle openings at the tip of the print head in a grid-like distribution, which makes it possible to record characters on a record carrier with suitable selective activation of the piezoelectric drive elements with electrical voltage pulses in the course of a line-wise movement of the write head. The tubular piezoelectric drive elements, as a result of their activation with the voltage pulses, bring about a corresponding pulse-like contraction of the ink channels, by means of the pressure pulses on the ink present in the ink channels are exercised, which in turn lead to the detachment of ink droplets at the nozzle openings of the ink channels and to their transfer to the recording medium.

Ein Nachteil der bisher bekannten Schreibköpfe dieser Art besteht darin, daß der Abstand zwischen den Düsenöffnungen und dem Aufzeichnungsträger nicht beliebig vergrößert werden kann und im Sinne einer möglichst genauen mosaikartigen Erzeugung von Schriftzeichen höchstens 0,5 bis 1 mm betragen darf. Es gibt aber Anwendungsfälle, bei denen ein größerer Abstand des Aufzeichnungsträgers zu fordern ist. Ein solcher Anwendungsfall ist beispielsweise das Beschriften von Sparbüchern im Bankwesen im Rahmen eines automatischen Buchungsvorganges. Hierbei kann die zu beschriftende Seite je nach ihrer Lage im Sparbuch bzw. je nach Zahl bereits durchgeführter Buchungsvorgänge einen großen oder kleinen Abstand zum Schreibkopf bzw. zu seinen Düsenöffnungen haben. Innerhalb eines Abstandsbereiches, der dann bis zu 3 mm oder mehr betragen kann, soll aber eine stets gleichbleibende Schreibgenauigkeit gewährleistet sein.A disadvantage of the previously known writing heads of this type is that the distance between the nozzle openings and the recording medium cannot be increased arbitrarily and in the sense of the most accurate possible mosaic-like creation of characters may not exceed 0.5 to 1 mm. However, there are applications in which a larger distance between the record carriers is required. One such application is, for example, the labeling of savings books in banking as part of an automatic booking process. Depending on its position in the passbook or the number of booking processes already carried out, the page to be labeled can have a large or small distance from the print head or its nozzle openings. Within a distance range, which can then be up to 3 mm or more, the writing accuracy should always be constant.

Sollen die Tintentröpfchen bei gleichbleibender Genauigkeit nach ihrem Austritt aus den Düsenöffnungen über einen größeren Abstand zum Aufzeichnungsträger bewegt werden, so müssen die sie hervorrufenden Druckimpulse mit größerer Intensität erzeugt werden, damit ein geradliniger Tröpfchenfluß gewährleistet ist. Hierzu kann die Amplitude der an die piezoelektrischen Antriebselemente angelegten Steuerspannungsimpulse erhöht werden, jedoch sind einer solchen Erhöhung relativ niedrige Grenzen gesetzt, die wohl durch das mechanische Verhalten der Antriebselemente selbst bedingt sind und nicht zum gewünschten Erfolg führen, sondern meist erhöhte Schreibungenauigkeiten zur Folge haben. Die Aufgabe der Erfindung besteht deshalb darin, für einen Schreibkopf eingangs genannter Art eine Konstruktion anzugeben, die es möglich macht, Aufzeichnungen mit zufriedenstellender Genauigkeit über größere Abstände als bisher zu erzeugen, ohne daß Beeinträchtigungen der Schreibgenauigkeit durch überhöhte Steuerspannungsamplituden in Kauf genommen werden müssen.If the ink droplets are to be moved over a greater distance from the recording medium after they have emerged from the nozzle openings with constant accuracy, then the pressure pulses which cause them must be generated with greater intensity so that a linear flow of droplets is ensured. For this purpose, the amplitude of the control voltage pulses applied to the piezoelectric drive elements can be increased, but such an increase has relatively low limits, which are probably due to the mechanical behavior of the drive elements themselves and do not lead to the desired success, but usually result in increased inaccuracies in writing. The object of the invention is therefore to provide a design for a write head of the type mentioned at the beginning which makes it possible to produce recordings with satisfactory accuracy over larger distances than before, without having to accept impairments in the write accuracy due to excessive control voltage amplitudes.

Diese Aufgabe wird für einen Schreibkopf eingangs genannter Art erfindungsgemäß dadurch gelöst, daß die Filteranordnung lediglich aus einer Schicht eines Kapillarfiltermaterials besteht und daß jeder Tintenkanal eine an diese Schicht unmittelbar angrenzende trichterförmige Erweiterung aufweist.This object is achieved according to the invention for a write head of the type mentioned at the outset in that the filter arrangement consists only of one layer of a capillary filter material and in that each ink channel has a funnel-shaped widening directly adjacent to this layer.

Diese Lösung der gestellten Aufgabe führt zu einwandfreien Aufzeichnungen auch über einen Abstand zum Aufzeichnungsträger in der Größenordnung von 3 mm oder mehr und wird mit einer gegenüber der vorbekannten erheblich einfacheren Schreibkopfkonstruktion erreicht.This solution to the problem at hand leads to flawless recordings even over a distance from the record carrier of the order of magnitude of 3 mm or more and is achieved with a considerably simpler write head construction than the previously known one.

Bei dem vorbekannten Schreibkopf sind zwischen den Tintenkanälen und dem ihnen gemeinsamen Tintenraum als Filteranordnung eine Drosselplatte und ein engmaschiges Gitter vorgesehen, welches verhindern soll, daß Luft durch die Tintenkanäle in den Tintenraum eintritt. Die Drosselplatte enthält für jeden Tintenkanal eine sehr enge Durchgangsöffnung, die Druckspitzen im Tintenversorgungssystem abbauen und eine gegenseitige Entkoppelung der Druckwirkungen der Tintenkanäle untereinander gewährleisten soll.In the previously known write head, a throttle plate and a close-meshed grating are provided between the ink channels and the ink space common to them as a filter arrangement, which is intended to prevent air from entering the ink space through the ink channels. The throttle plate contains a very narrow through opening for each ink channel, which is intended to reduce pressure peaks in the ink supply system and to ensure a mutual decoupling of the pressure effects of the ink channels from one another.

Bei einem Schreibkopf nach der Erfindung wird nun keine= besondere Drosselplatte verwendet, sondern zwischen den Tintenkanälen und dem Tintenraum ist lediglich eine Filteranordnung in Form einer Schicht eines Kapillarfiltermaterials vorgesehen. Zusätzlich hat aber jeder Tintenkanal eine an diese Schicht angrenzende trichterförmige Erweiterung. Es hat sich gezeigt, daß mit dieser Anordnung eine erheblich bessere Ausnutzung der Energie der mit den piezoelektrischen Antriebselementen erzeugten Druckimpulse möglich ist, die dazu führt, daß die an den Düsenöffnungen austretenden Tintentröpfchen unter Beibehaltung ihres vorgegebenen Weges einen erheblich größeren Abstand zum Aufzeichnungsträger durchfliegen können.In a write head according to the invention, no special throttle plate is now used, but only a filter arrangement in the form of a layer of a capillary between the ink channels and the ink space provided filter material. In addition, each ink channel has a funnel-shaped extension adjacent to this layer. It has been shown that with this arrangement a considerably better utilization of the energy of the pressure pulses generated with the piezoelectric drive elements is possible, which leads to the fact that the ink droplets emerging at the nozzle openings can fly through a considerably greater distance to the recording medium while maintaining their predetermined path.

Dies kann darauf zurückgeführt werden, daß die an die Filterschicht angrenzenden trichterförmigen, also kontinuierlichen Erweiterungen der Tintenkanäle auch eine entsprechende Erhöhung des Durchströmungsquerschnitts des Kapillarfiltermaterials zur Folge haben, wodurch sich für jeden dieser Querschnitte der Strömungswiderstand verringert. Da außerdem eine Drosselplatte mit engen Durchgangsöffnungen fehlt, ergibt sich eine beachtliche Erhöhung der Strömungsgeschwindigkeit. Dabei ist festzustellen, daß trotz fehlender Drosselplatte praktisch keine schädlichen Auswirkungen von Druckspitzen auftreten und eine ausreichende Entkopplung der Druckwirkungen der Tintenkanäle untereinander gegeben ist. Die Trichterform der Erweiterungen vermeidet Übergangskanten und damit schädliche Reflexionen.This can be attributed to the fact that the funnel-shaped, ie continuous widenings of the ink channels adjoining the filter layer also result in a corresponding increase in the flow cross section of the capillary filter material, as a result of which the flow resistance for each of these cross sections is reduced. In addition, since a throttle plate with narrow through openings is missing, the flow velocity increases considerably. It should be noted that despite the lack of a throttle plate there are practically no harmful effects of pressure peaks and there is sufficient decoupling of the pressure effects of the ink channels from one another. The funnel shape of the extensions avoids transition edges and thus harmful reflections.

Besonders vorteilhafte Ergebnisse werden in der Praxis erreicht, wenn das Filtermaterial eine Maschenbreite von etwa 0,035 mm und eine Dicke von etwa 0,05 mm aufweist. Diese Dimensionierung scheint eine besonders gute Kapillarwirkung des Filtermaterials zur kontinuierlichen Versorgung der einzelnen Tintenkanäle mit Tinte, verbunden mit einer hinreichenden Filterwirkung, zu gewährleisten.Particularly advantageous results are achieved in practice if the filter material has a mesh width of approximately 0.035 mm and a thickness of approximately 0.05 mm. This dimensioning seems to ensure a particularly good capillary action of the filter material for the continuous supply of ink to the individual ink channels, combined with an adequate filter action.

Als trichterförmige Erweiterungen der Tintenkanäle können in verschiedenster Weise geformte Aussparungen in dem die Tintenkanäle enthaltenden Körper vorgesehen sein. So ist es beispielsweise möglich, halbkugelige, hyperbolische oder elliptische Vertiefungen in der Fläche vorzusehen, an der die Tintenkanäle münden und der Filterschicht gegenüberstehen. Besonders vorteilhaft hat sich jedoch eine Ausführung erwiesen, bei der die Erweiterungen der Tintenkanäle kegelförmig mit einem Öffnungswinkel von etwa 60° ausgebildet sind.Cutouts in the body containing the ink channels can be provided in various ways as funnel-shaped extensions of the ink channels. For example, it is possible to provide hemispherical, hyperbolic or elliptical depressions in the area where the ink channels open and face the filter layer. However, an embodiment has proven to be particularly advantageous in which the extensions of the ink channels are conical in shape with an opening angle of approximately 60 °.

Bei dieser Ausbildung ist wiederum eine vorteilhafte Dimensionierung der Erweiterungen gegeben, wenn diese an ihrem Übergang zum Filtermaterial einen Durchmesser von etwa 3 mm aufweisen. Diese Abmessung steht dann in einem besonders günstigen Verhältnis zu dem Durchmesser der Tintenkanäle, der üblicherweise in der Größenordnung von 0,5 bis 0,7 mm an der Mündungsstelle zur Filterschicht liegt.In this embodiment, the extensions are again advantageously dimensioned if they have a diameter of approximately 3 mm at their transition to the filter material. This dimension is then in a particularly favorable relationship to the diameter of the ink channels, which is usually in the order of magnitude of 0.5 to 0.7 mm at the mouth of the filter layer.

Bei dem vorbekannten Schreibkopf ist in dem allen Tintenkanälen gemeinsamen Tintenraum zur zusätzlichen Dämpfung von Druckschwankungen eine Luftblase eingeschlossen. Eine solche Luftblase ist bei einem Schreibkopf nach der Erfindung nicht erforderlich, was bedeutet, daß der Tintenraum ausschließlich mit Tinte gefüllt ist.In the previously known write head, an air bubble is enclosed in the ink space common to all ink channels for additional damping of pressure fluctuations. Such an air bubble is not required in a print head according to the invention, which means that the ink space is filled with ink only.

In der Figur ist schematisch in einem Querschnitt als Ausführungsbeispiel ein Schreibkopf nach der Erfindung dargestellt. Dieser Schreibkopf besteht im wesentlichen aus einem Kunststoffkörper 10, der konisch ausgebildet ist und in den Tintenkanäle 11 eingearbeitet sind, welche zur linken Spitze des Körpers 10 hin konvergieren und dort mit Düsenöffnungen 12 münden. Mit Abstand zur Spitze des Körpers 10 ist ein Aufzeichnungsträger 13 angeordnet, auf den die aus den Düsenöffnungen 12 austretenden Tintentröpfchen infolge mosaikartiger Verteilung der Düsenöffnungen 12 bei Relativbewegung zwischen dem Körper 10 und dem Aufzeichnungsträger 13 Schriftzeichen aufzeichnen können.In the figure, a write head according to the invention is shown schematically in a cross section as an exemplary embodiment. This write head essentially consists of a plastic body 10, which is conical and is incorporated in the ink channels 11, which converge towards the left tip of the body 10 and open there with nozzle openings 12. At a distance from the tip of the body 10 is a record carrier 13 Arranged on which the ink droplets emerging from the nozzle openings 12 can record characters as a result of the mosaic-like distribution of the nozzle openings 12 with relative movement between the body 10 and the recording medium 13.

Die Tintentröpfchen werden dadurch erzeugt, daß röhrenförmige piezoelektrische Antriebselemente 14, die die Tintenkanäle 11 umgeben, selektiv in schneller Folge mit Spannungsimpulsen angesteuert werden, wodurch sie sich nach Art einer Kontraktion verformen und im jeweiligen Tintenkanal 11 einen Druckimpuls erzeugen, der sich in der im Tintenkanal 11 vorhandenen Tinte so auswirkt, daß die Tinte an den Düsenöffnungen 12 tröpfchenförmig abgelöst und auf den Aufzeichnungsträger 13 geschossen wird.The ink droplets are generated in that tubular piezoelectric drive elements 14, which surround the ink channels 11, are selectively driven in rapid succession with voltage pulses, as a result of which they deform in the manner of a contraction and generate a pressure pulse in the respective ink channel 11, which pulse occurs in the ink channel 11 existing ink affects so that the ink is detached at the nozzle openings 12 and shot onto the recording medium 13.

Zur Versorgung der Tintenkanäle 11 mit Tinte ist ein Tintenversorgungssystem vorgesehen, dessen Vorratsbehälter in der Figur nicht dargestellt ist. Die Tinte wird von einem solchen Vorratsbehälter her bei 15 dem Schreibkopf zugeführt und tritt in einen allen Tintenkanälen gemeinsamen Tintenraum 16 ein, der zwischen dem Körper 10 und einer hinteren Abschlußplatte 17 ausgebildet ist, welche mit dem Körper 10 in abdichtender Verbindung steht und z.B. verschraubt (nicht dargestellt) ist. Der gemeinsame Tintenraum 16 ist so schmal, daß die bei 15 zugeführte Tinte durch Kapillarwirkung in ihm emporsteigt und ihn insgesamt ausfüllt. In der praktischen Ausführung eines Schreibkopfes kann die Breite des Tintenraums 16 beispielsweise 0,1 bis 0,3 mm betragen.To supply the ink channels 11 with ink, an ink supply system is provided, the reservoir of which is not shown in the figure. The ink is supplied from such a reservoir at 15 to the print head and enters an ink space 16 common to all ink channels, which is formed between the body 10 and a rear end plate 17, which is in sealing connection with the body 10 and e.g. is screwed (not shown). The common ink space 16 is so narrow that the ink supplied at 15 rises through it by capillary action and fills it up as a whole. In the practical embodiment of a write head, the width of the ink space 16 can be, for example, 0.1 to 0.3 mm.

Der Tintenraum 16 wird auf seiner linken Seite durch eine Schicht 18 eines Filtermaterials begrenzt, welches beispielsweise aus einem faserigen Kunststoffmaterial mit einer Maschendichte von 0,035 mm bestehen kann. Die Dicke dieser Schicht 18 kann etwa 0,05 bis 0,3 mm betragen.The ink space 16 is delimited on its left side by a layer 18 of a filter material, which is made, for example, of a fibrous plastic material with a mesh density of 0.035 mm. The thickness of this layer 18 can be approximately 0.05 to 0.3 mm.

Aus der Figur ist zu ersehen, daß die einzelnen Tintenkanäle 11 mehr als doppelt so lang wie die Antriebselemente 14 sind und mit der Schicht 18 des Filtermaterials über jeweils eine trichterförmige Erweiterung 19 in Verbindung stehen, die im dargestellten Ausführungsbeispiel kegelförmig ausgebildet ist. Der Öffnungswinkel dieser Trichterform kann z.B. 60° betragen. Die Tintenkanäle 11 können z.B. eine Länge von 35 mm haben, während die Antriebselemente 14 dann etwa 12 mm lang sird.From the figure it can be seen that the individual ink channels 11 are more than twice as long as the drive elements 14 and are connected to the layer 18 of the filter material via a funnel-shaped extension 19, which is conical in the illustrated embodiment. The opening angle of this funnel shape can e.g. Be 60 °. The ink channels 11 can e.g. have a length of 35 mm, while the drive elements 14 are then about 12 mm long.

Wenn das piezoelektrische Antriebselement 14 eines Tintenkanals 11 mit einem elektrischen Spannungsimpuls angesteuert wird, so wird in dem Tintenkanal 11 innerhalb der ihn ausfüllenden Tinte ein Druckimpuls erzeugt, der sich in Richtung zur Düsenöffnung 12, jedoch auch in entgegengesetzter Richtung, nämlich zur Schicht 18 des Filtermaterials hin, fortpflanzt. Der Druckimpuls bewirkt die Ablösung eines Tintentröpfchens an der Düsenöffnung 12 sowie dessen Bewegung zum Aufzeichnungsträger 13 hin. Durch die Erweiterung 19 und die dadurch bedingte Erhöhung des Strömungsquerschnitts der Filtermaterialschicht 18 ergibt sich eine gegenüber vergleichbaren bekannten Schreibköpfen größere Strömungsgeschwindigkeit der Tinte, wodurch erreicht wird, daß der Aufzeichnungsträger 13 zu den Düsenöffnungen 12 einen entsprechend größeren Abstand haben kann. In der Praxis hat sich gezeigt, daß dieser Abstand in der Größenordnung von 3 mm liegen kann.If the piezoelectric drive element 14 of an ink channel 11 is driven with an electrical voltage pulse, then a pressure pulse is generated in the ink channel 11 within the ink filling it, which pressure pulse moves in the direction of the nozzle opening 12, but also in the opposite direction, namely to the layer 18 of the filter material there, reproduced. The pressure pulse causes the detachment of an ink droplet at the nozzle opening 12 and its movement towards the recording medium 13. The enlargement 19 and the consequent increase in the flow cross section of the filter material layer 18 results in a higher flow velocity of the ink compared to comparable known writing heads, which means that the recording medium 13 can have a correspondingly greater distance from the nozzle openings 12. In practice it has been shown that this distance can be of the order of 3 mm.

Von Wichtigkeit scheint hierfür ferner die Tatsache zu sein, daß die piezoelektrischen Antriebselemente 14 die Tintenkanäle 11 an einer Stelle umgeben, die möglichst nahe den Erweiterungen 19 angeordnet ist, während die restliche freie Länge der Tintenkanäle 11 vor den Antriebselementen 14 liegt.Of importance for this also seems to be the fact that the piezoelectric drive elements 14 surround the ink channels 11 in a position that is arranged as close as possible to the extensions 19, while the remaining free length of the ink channels 11 lies in front of the drive elements 14.

Claims (6)

1. Piezoelektrisch betriebener Schreibkopf für Tintenmosaikschreibeinrichtungen mit mehreren Schreibdüsen in Form von Schreibflüssigkeit aufnehmenden Tintenkanälen, die jeweils von einem piezoelektrischen An triebselement umschlossen sind und über eine Filter anordnung mit einem ihnen gemeinsamen Tintenraum in Verbindung stehen, wobei die Tintenkanäle eine wesentlich größere Länge als die Antriebselemente heben, dadurch gekennzeichnet, daß die Filteranordnung lediglich aus einer Schicht (18) eines Kapillarfiltermaterials besteht und daß jeder Tintenkanal (11) eine an diese Schicht (18) unmittelbar angrenzende trichterförmige Erweiterung (19) aufweist.1. Piezoelectrically operated write head for ink mosaic writing devices with a plurality of writing nozzles in the form of writing fluid receiving ink channels, each of which is enclosed by a piezoelectric drive element and are arranged via a filter arrangement with an ink space common to them, the ink channels being of a much greater length than the drive elements lift, characterized in that the filter arrangement consists only of one layer (18) of a capillary filter material and that each ink channel (11) has a funnel-shaped extension (19) immediately adjacent to this layer (18). 2. Schreibkopf nach Anspruch 1, dadurch gekennzeichnet, daß das Filtermaterial (18) eine Maschenweite von etwa 0,035 mm und eine Dicke von etwa 0,05 mm aufweist.2. Writing head according to claim 1, characterized in that the filter material (18) has a mesh size of approximately 0.035 mm and a thickness of approximately 0.05 mm. 3. Schreibkopf nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Erweiterungen (19) der Tintenkanäle (11) kegelförmig mit einem Öffnungswinkel von etwa 60° ausgebildet sind.3. Print head according to claim 1 or 2, characterized in that the extensions (19) of the ink channels (11) are conical with an opening angle of about 60 °. 4. Schreibkopf nach Anspruch 3, dadurch gekennzeichnet, daß die Erweiterungen (19) an ihrem Übergang zum Filtermaterial (18) einen Durchmesser von etwa 3 mm aufweisen.4. Print head according to claim 3, characterized in that the extensions (19) at their transition to the filter material (18) have a diameter of about 3 mm. 5. Schreibkopf nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß der Tintenraum (16) ausschließlich mit Tinte gefüllt ist.5. Print head according to one of the preceding claims, characterized in that the ink space (16) is filled exclusively with ink. 6. Schreibkopf nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die piezoelektrischen Antriebselemente (14) nahe den Erweiterungen (19) der Tintenkanäle (11) angeordnet sind.6. Writing head according to one of the preceding claims, characterized in that the piezoelectric drive elements (14) are arranged near the extensions (19) of the ink channels (11).
EP84103655A 1983-04-12 1984-04-03 Piezoelectrically operated write head for ink mosaic recording devices Expired EP0121894B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3313156 1983-04-12
DE3313156A DE3313156A1 (en) 1983-04-12 1983-04-12 PIEZOELECTRICALLY OPERATED WRITING HEAD FOR INK MOSAIC WRITING DEVICES

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EP0121894A2 true EP0121894A2 (en) 1984-10-17
EP0121894A3 EP0121894A3 (en) 1985-06-12
EP0121894B1 EP0121894B1 (en) 1986-10-15

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EP84103655A Expired EP0121894B1 (en) 1983-04-12 1984-04-03 Piezoelectrically operated write head for ink mosaic recording devices

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US (1) US4514743A (en)
EP (1) EP0121894B1 (en)
JP (1) JPS59198164A (en)
DE (2) DE3313156A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0500068A2 (en) * 1991-02-20 1992-08-26 Canon Kabushiki Kaisha Ink jet recording head, recording apparatus using same and method for manufacturing same
EP0596252A1 (en) * 1992-10-02 1994-05-11 Canon Kabushiki Kaisha Ink supply mechanism, ink jet cartridge provided with such a mechanism, and ink jet recording apparatus provided with such a mechanism

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3405062A1 (en) * 1984-02-13 1985-08-22 Nixdorf Computer Ag, 4790 Paderborn Print head for ink jet matrix printing devices
US4877745A (en) * 1986-11-17 1989-10-31 Abbott Laboratories Apparatus and process for reagent fluid dispensing and printing
JP2656481B2 (en) * 1987-02-13 1997-09-24 キヤノン株式会社 Inkjet recording head
US4831389A (en) * 1987-12-21 1989-05-16 Hewlett-Packard Company Off board ink supply system and process for operating an ink jet printer
US4999652A (en) * 1987-12-21 1991-03-12 Hewlett-Packard Company Ink supply apparatus for rapidly coupling and decoupling a remote ink source to a disposable ink jet pen
US4864329A (en) * 1988-09-22 1989-09-05 Xerox Corporation Fluid handling device with filter and fabrication process therefor
US5121132A (en) * 1989-09-29 1992-06-09 Hewlett-Packard Company Ink delivery system for printers
US5610645A (en) * 1993-04-30 1997-03-11 Tektronix, Inc. Ink jet head with channel filter
US5742314A (en) * 1994-03-31 1998-04-21 Compaq Computer Corporation Ink jet printhead with built in filter structure
US6521187B1 (en) 1996-05-31 2003-02-18 Packard Instrument Company Dispensing liquid drops onto porous brittle substrates
US6203759B1 (en) 1996-05-31 2001-03-20 Packard Instrument Company Microvolume liquid handling system
US6537817B1 (en) 1993-05-31 2003-03-25 Packard Instrument Company Piezoelectric-drop-on-demand technology
DE69518191T2 (en) * 1994-05-20 2001-05-31 Canon K.K., Tokio/Tokyo Ink supply device and associated ink jet recording device
US5734399A (en) * 1995-07-11 1998-03-31 Hewlett-Packard Company Particle tolerant inkjet printhead architecture
JPH0966603A (en) * 1995-08-31 1997-03-11 Brother Ind Ltd Driving method for ink injector
US6083762A (en) * 1996-05-31 2000-07-04 Packard Instruments Company Microvolume liquid handling system
US20030215957A1 (en) * 1998-02-20 2003-11-20 Tony Lemmo Multi-channel dispensing system
NL1011127C2 (en) * 1999-01-25 2000-07-27 Oce Tech Bv Ink delivery device.
CN1565845A (en) 1999-06-30 2005-01-19 西尔弗布鲁克研究股份有限公司 Printhead support structure and assembly

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2543397A1 (en) * 1975-09-29 1977-04-07 Siemens Ag DEVICE FOR DAMPING LIQUID VIBRATIONS IN INK SUPPLY SYSTEMS OF INK MUSAIC WRITING DEVICES
DE2543451C2 (en) * 1975-09-29 1982-05-06 Siemens AG, 1000 Berlin und 8000 München Piezoelectrically operated writing head for ink mosaic writing devices
DE3126372A1 (en) * 1980-07-04 1982-09-02 Hitachi Koki Co., Ltd., Tokyo Ink-jet printer

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2164113C3 (en) * 1971-12-23 1975-03-27 Olympia Werke Ag, 2940 Wilhelmshaven Ink jet head, in particular for an ink jet writing unit
DE2460573A1 (en) * 1974-12-20 1976-07-01 Siemens Ag DEVICE FOR INKJET PEN FOR SUPPLYING PIEZOELECTRICALLY OPERATED WRITING NOZZLES WITH WRITING LIQUID
US4158847A (en) * 1975-09-09 1979-06-19 Siemens Aktiengesellschaft Piezoelectric operated printer head for ink-operated mosaic printer units
DE2543420C3 (en) * 1975-09-29 1980-09-11 Siemens Ag, 1000 Berlin Und 8000 Muenchen Piezoelectric drive element for writing heads in ink mosaic writing devices
JPS55158980A (en) * 1979-05-29 1980-12-10 Seiko Epson Corp Ink jet recording head
US4233610A (en) * 1979-06-18 1980-11-11 Xerox Corporation Hydrodynamically damped pressure pulse droplet ejector
DE3006726C2 (en) * 1980-02-22 1982-03-11 Siemens AG, 1000 Berlin und 8000 München Ink writing device
DE3123689C2 (en) * 1981-06-15 1987-01-08 Siemens AG, 1000 Berlin und 8000 München Device for ejecting ink droplets in ink writing devices as required
JPS581569A (en) * 1981-06-29 1983-01-06 Canon Inc Liquid injecting recording head
JPS5859857A (en) * 1981-10-07 1983-04-09 Nec Corp Ink jet type printing head

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2543397A1 (en) * 1975-09-29 1977-04-07 Siemens Ag DEVICE FOR DAMPING LIQUID VIBRATIONS IN INK SUPPLY SYSTEMS OF INK MUSAIC WRITING DEVICES
DE2543451C2 (en) * 1975-09-29 1982-05-06 Siemens AG, 1000 Berlin und 8000 München Piezoelectrically operated writing head for ink mosaic writing devices
DE3126372A1 (en) * 1980-07-04 1982-09-02 Hitachi Koki Co., Ltd., Tokyo Ink-jet printer

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0500068A2 (en) * 1991-02-20 1992-08-26 Canon Kabushiki Kaisha Ink jet recording head, recording apparatus using same and method for manufacturing same
EP0500068A3 (en) * 1991-02-20 1992-12-02 Canon Kabushiki Kaisha Ink jet recording head, recording apparatus using same and method for manufacturing same
US5808644A (en) * 1991-02-20 1998-09-15 Canon Kabushiki Kaisha Method for manufacturing an ink jet recording head having ink filter
EP0596252A1 (en) * 1992-10-02 1994-05-11 Canon Kabushiki Kaisha Ink supply mechanism, ink jet cartridge provided with such a mechanism, and ink jet recording apparatus provided with such a mechanism
US5481289A (en) * 1992-10-02 1996-01-02 Canon Kabushiki Kaisha Ink supply mechanism, ink jet cartridge provided with such a mechanism, and ink jet recording apparatus provided with such a mechanism

Also Published As

Publication number Publication date
US4514743A (en) 1985-04-30
EP0121894A3 (en) 1985-06-12
DE3313156A1 (en) 1984-10-18
EP0121894B1 (en) 1986-10-15
DE3460948D1 (en) 1986-11-20
JPS59198164A (en) 1984-11-09

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