EP0382741B1 - Dispositif pour controler la projection de gouttes par les buses de sortie d'unetete d'ecriture a encre - Google Patents

Dispositif pour controler la projection de gouttes par les buses de sortie d'unetete d'ecriture a encre Download PDF

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Publication number
EP0382741B1
EP0382741B1 EP88907604A EP88907604A EP0382741B1 EP 0382741 B1 EP0382741 B1 EP 0382741B1 EP 88907604 A EP88907604 A EP 88907604A EP 88907604 A EP88907604 A EP 88907604A EP 0382741 B1 EP0382741 B1 EP 0382741B1
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EP
European Patent Office
Prior art keywords
ink
arrangement according
circuit
comb
sensor
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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
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EP88907604A
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German (de)
English (en)
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EP0382741A1 (fr
Inventor
Ernst Goepel
Hans Kusmierz
Wilfried Houben
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Siemens AG
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Siemens AG
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Priority claimed from DE19873732395 external-priority patent/DE3732395A1/de
Priority claimed from DE19873732396 external-priority patent/DE3732396A1/de
Application filed by Siemens AG filed Critical Siemens AG
Publication of EP0382741A1 publication Critical patent/EP0382741A1/fr
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Publication of EP0382741B1 publication Critical patent/EP0382741B1/fr
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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
    • B41J2/165—Preventing or detecting of nozzle clogging, e.g. cleaning, capping or moistening for nozzles
    • B41J2/16579—Detection means therefor, e.g. for nozzle clogging

Definitions

  • the invention relates to an arrangement for monitoring the droplet ejection from outlet nozzles of an ink writing head according to the preamble of patent claim 1.
  • the representation of characters or of graphic patterns with ink writing devices is known to be based on the fact that individual droplets are ejected in a controlled manner from outlet nozzles of an ink writing head. Such arrangements are referred to as drop-on-demand (DOD) arrangements.
  • DOD drop-on-demand
  • characters or graphic patterns in the form of a plurality of individual points are thus built up in a grid pattern on the recording medium.
  • the quality of recordings made in this way, the so-called writing quality depends essentially on the number of droplets by which a character is formed.
  • each outlet nozzle is assigned its own drive element, for example in the form of an electrically controllable piezo element. This must have a co-ordinated behavior for an error-free operation together with the ink channel and an ink supply.
  • This known method requires special charging electrodes, to which a relatively high voltage (up to 300 V) must be applied in order to charge the ink droplets. This not only results in additional design effort, but also protective measures against contact with the live parts must be provided due to the high voltages.
  • DE-36 34 034 A1 describes an ink drop detector for an inkjet printer with an ink ejecting nozzle, which comprises a plurality of electrodes, at least one of which can be brought into a position in which it is opposite the nozzle at a predetermined distance.
  • the change in resistance between the first electrode and another electrode is detected when conductive ink struck by the nozzle reaches the first electrode.
  • the surface of the ink drop sensor is mechanically cleaned using a rubber wiper, thereby limiting the frequency for ink drop detection.
  • the invention has for its object to provide measures for monitoring the droplet ejection, with which the function of an ink writing head with a plurality of outlet nozzles by determining the impingement of ink droplets without a visual check of print patterns is determined, which without additional protective measures, a safe and clear evaluation of the Enable measurement results with little circuitry effort and which only require relatively simple constructive means, in particular the manufacture of the sensor plate, the assembly of the ink droplet sensor and the installation in the ink writing head, but also the use as a test or inspection device in production, e.g. as a calibration device is advantageously improved.
  • an ink writing head 1 known per se which in the example consists of a nozzle plate 2 with nine outlet nozzles 3, a head part 4 with nine ink channels 5 and drive elements 6 assigned to them, and an ink supply part 7. This is connected via an ink feed 8 to an ink reservoir, not shown here.
  • 1 can also be arranged several times in several rows perpendicular to the plane of the drawing. Four such rows would then form a write head with 32 nozzles, the nozzles of the individual rows being offset from one another.
  • the ink droplet sensor 11 according to the invention is arranged at a distance 10 from the write head 1.
  • the electrode comb has, at least in the region of the point of impact of the ink droplets, a multiplicity of conductor tracks 18 and 19 running parallel in the outlet region of the ink droplets.
  • the device for removing the liquid supplied by the impingement of ink droplets exists made of non-conductive porous material; it can be constructed in one layer or preferably from several sub-layers.
  • the connection electrodes 13 and 14 are connected to an evaluation circuit 20 which, as will be discussed in more detail later, depending on the impact of one or more ink droplets on the electrode comb 12, emits a corresponding signal, the sensor signal SM.
  • FIGS. 2 and 3 show an exemplary embodiment of the electrode comb 12 of the ink droplet sensor in a top view (FIG. 2) and in a sectional view (FIG. 3).
  • the electrode comb is formed by two comb parts 121 and 122, the tongue-shaped conductor tracks 18, 19 of which lie next to one another in the region of the points of impact for the ink droplets and form the comb structure.
  • the comb parts 121 and 122 with the conductor tracks 18 and 19 are applied here to the suction block 17 consisting of the porous, non-conductive layer.
  • Each of these comb parts 121 and 122 is electrically accessible from the outside via the connection electrodes 13 and 14.
  • FIG 3 shows the structure in detail.
  • the suction block 17 consists of two partial layers 15 and 16 of absorbent material with the thicknesses S1 and S2.
  • An insulating layer in the form of a gold-coated insulating film 21 is laminated onto the uppermost partial layer 15, which is then structured according to the division ratio T of the electrode comb and is provided with the conductor tracks 18 and 19.
  • T ⁇ D must be present in order to form an electrical resistance bridge between adjacent conductor tracks 18 and 19 and thus between comb parts 121 and 122.
  • FIG. 3 shows that an ink drop 9 meets this condition when it hits the surface of the ink droplet sensor, that is to say it brings about a significant reduction in resistance between two adjacent conductor tracks, which can be evaluated at the connection electrodes 13 and 14 by the evaluation circuit.
  • the ink droplet 9 strikes, the amount of liquid is first absorbed by the upper porous sub-layer 15, transported downward and finally penetrates into the second sub-layer 16.
  • the non-conductive porous sub-layers 15 and 16 act as a kind of suction pump with a capillary effect.
  • the efficiency of this suction pump can be adjusted to specific applications by selecting the porosity and / or the number or the thickness S1, S2 of the partial layers.
  • the porosity P1 and P2 of the two layers 15 and 16 is different. It is advantageous if the porosity of the individual layers increases with increasing distance from the electrode comb (P2> P1). This ensures that a liquid transport preferably takes place from the upper sub-layer 15 to the lower sub-layer 16.
  • Duran filter glass for the upper partial layer 15 and so-called Millipore filter paper for the lower partial layer 16 are preferably suitable as materials for the individual partial layers 15 and 16 with different porosities.
  • the pore sizes of the upper porous partial layer 15 can be between 0.01 and 0 , 02, the pore sizes of the lower porous partial layer 16 are between 0.005 and 0.01 mm.
  • the comb structures described can advantageously be produced by the thin-film or thick-film technique known per se.
  • the structures of the electrode comb arrangement are designed as bifilar conductor tracks, which results in the advantage that the conductor tracks of the comb structure are controllable, e.g. can be connected to each other during individual pauses in measurement. An example of this is shown in FIG. 4.
  • the conductor tracks 181 and 191 of the two comb parts 123 and 124 are meandered on the suction block 17 here. Its construction and the formation of the conductor tracks 181 and 191 can be done in the manner described with reference to FIG. 3. As before, the conductor tracks run parallel next to each other in the area where the ink droplets meet. In contrast to the previously described embodiment, the embodiment specified here offers the possibility of providing a second pair of connecting electrodes 23 and 24 in addition to the connecting electrodes 13 and 14 which lead to the outside and via which the conductor tracks 181 and 191 can be electrically connected to one another. The connection electrodes 23 and 24 are not connected to one another for the duration of a measurement process, that is to say for the duration during which the impact of ink droplets is detected.
  • the mode of operation of the detection for the impact of ink droplets then takes place as described with reference to FIG. 2 and FIG. 3.
  • the connections 23 and 24 can now be connected to one another via a switch (not shown here) which is actuated in the measurement pauses, that is to say when no ink droplets are detected. It is thus possible to use the conductor tracks 181 and 191 for heating and thus for evaporating the ink droplets during the measurement pauses with the aid of a current source (not shown here) which can be connected to the connections 13 and 14. This has the advantage that in addition to the capillary action of the suction block, there is also liquid removal by evaporation.
  • FIG. 5 An exemplary embodiment of this is shown in FIG. 5.
  • the circuit shown there essentially consists of a voltage divider consisting of a fixed resistor 30 and the variable measuring resistor 31. This represents the respective current resistance value between the conductor tracks 18 and 19 (Fig.2) or 181,191 (Fig.4) of the electrode comb, ie the circuit shown is connected at this point to the connection electrodes 13 and 14 of the electrode comb.
  • the tap between the resistors 30, 31 of the voltage divider is connected to the inputs of a comparator 32.
  • the measuring resistor 31 thus becomes smaller, which means that the instantaneous value Um briefly becomes smaller than the temporal mean value Umm.
  • a brief change in level from 1 to 0 occurs at the output of the comparator 32. This transition is buffered in the bistable circuit 37 and further processed by the printer controller. After droplet detection, the bistable circuit 37 is reset via its reset input with the reset signal R and the sensor is thus activated for the impact and evaluation of a next ink droplet from another nozzle of the write head.
  • the printer controller By monitoring the time period between the excitation for droplet ejection by the printer controller and the occurrence of the sensor signal, it is possible to check the functionality of the individual nozzles. If there is no sudden change in resistance after a certain period of time, which can be set depending on predetermined parameters, such as printer structure, flight time of the droplets, ink composition, etc., the printer controller recognizes that the excited nozzle is not working.
  • the circuit arrangement described works with direct current, i.e. the voltage divider circuit is connected between a positive voltage source and ground.
  • this can lead to decomposition of the ink liquid especially when several ink droplets arriving in quick succession are necessary for the evaluation of ink droplets.
  • the ink liquid in this case is exposed to a current flow for a period of t ⁇ 100 ms, which can cause electrolytic changes.
  • the dye precipitates out of the solvent, which leads to solidification, which means that capillary suction is no longer possible.
  • this problem is solved in that the ink droplet sensor is operated with AC voltage.
  • An exemplary embodiment of this is shown in FIG. 6.
  • the evaluation circuit shown there also has the voltage divider circuit, consisting of the fixed resistor 30 and a resistor 31 representing the current resistance value between the conductor tracks.
  • the voltage divider circuit 30, 31 is here connected to an AC voltage generator 38.
  • a demodulator 33 is connected between the dividing point of the voltage divider circuit 30, 31 and the comparator 32 and operates in the circuit configuration selected in FIG. 7 as a so-called peak value rectifier. A voltage value is therefore available at its output which corresponds to the current peak value of the voltage at the dividing point.
  • FIG. 7 shows a detailed circuit structure as an example of an embodiment for the evaluation circuit according to FIG. 6.
  • an electrically insulating carrier plate 26 is provided with a metal layer. This is preferably done by evaporating a glass plate with a thickness of 0.1 to 0.8 mm with a base metallization of Ti, Cu.
  • a photoresist layer is applied to both sides of this. Subsequently, the pattern of the electrode comb structure desired later on the sensor plate 25 with the conductor tracks 18, 19 is generated on one side and this is galvanically reinforced to 10 ... 20 ⁇ m Ni.
  • the area of a spray window 28 is exposed on both sides and after the base metallization has been etched off, the glass is etched away in this area, so that the conductor tracks 18, 19 span the now glass-free spray window 28.
  • so-called contacting windows 27 are etched free in this glass etching process.
  • the sensor plate 25 can be produced to a great extent and can be connected and contacted with the suction block in a simple manner. Details will be described with reference to FIGS. 9 and 10.
  • Fig. 9 in supervision
  • Fig. 10 in a sectional view
  • a housing 29 the suction block 17, the sensor plate 25 and contact springs 42 arranged on both sides Housing 29, designed as an electrically non-conductive plastic injection-molded part, serves to accommodate these parts and is in turn fastened in printer chassis 41 with the aid of the latching tongues 40 belonging to the housing.
  • the surface quality of the suction block 17 consisting of non-conductive, open-porous material, such as, for example, suction ceramic, filter glass or foam, is subject to certain requirements only with regard to the side facing the ink writing head 1.
  • the flatness of this surface should be of the order of magnitude of the pore size of the porous suction block 17 in order to ensure that the flat sensor plate 25 is supported on it.
  • the sensor plate 25 has the comb parts 121, 122, the conductor tracks 18, 19, the spray window 28 and two contacting windows 27.
  • the mechanical assignment of the sensor plate 25 to the suction block 17, whose side provided with the conductor tracks 18, 19 faces the suction block 17, is done by the multifunctional contact springs 42 arranged on both sides.
  • the suction block 17 is inserted into the housing 29 and after the subsequent placement of the sensor plate 25 on the suction block 17, these metal contact springs 42 pressed into corresponding insertion openings 43 of the housing 29.
  • the contact springs 42 have latching lugs 44 which engage securely in a recess 45 when inserted into the housing 29. This ensures that the three spring tongues 46 formed at one end of the contact springs 42 resiliently rest on the sensor plate 25.
  • the two outer spring tongues 46 each press on the support of the sensor plate 25 and guarantee a gap-free support of the sensor plate 25 on the suction block 17.
  • the respective middle spring tongue 46 lies in the area of the contacting window 27 and presses directly on the respective contact surface of the electrode comb structure 18 , 19 and thereby establishes the electrical contact.
  • the respective other end of the contact springs 42 forms the connection electrode 13 or 14.
  • the electrical connection from the electrode comb structure to the electronic evaluation circuit, not shown here, is established via a connection designed as a flat plug 47 for standardized plug sleeves.
  • the ink sprayed onto the conductor tracks 18, 19 is drawn capillary into the suction block 17.
  • the absorbency of the suction block 17 depends on its suction volume and its material, on the ink and on the frequency of the spray test.
  • an opening 48 can be provided in the housing of the device for an additional ink disposal, which is filled with a suction material of higher porosity than that of the suction block 17.
  • ink droplets which is associated with a sudden reduction in resistance in the course of the conductor tracks of the electrode comb, is evaluated in a circuit arrangement (20 in FIG. 1) which emits the sensor signal SM with each impact of one or more ink droplets.
  • the height of the splash window 28 is adapted to the vertical distance of the outer nozzles of the ink writing head.
  • the width of the spray window 28 depends on the horizontal extent of the nozzle exit area of the ink writing head. In the case of a single-row nozzle arrangement, only a narrow, and in the case of multi-row, a correspondingly wider spray window 28 is required. It is also possible to orient the spatially separated rows of nozzles in succession to the spray window 28. This is more advantageous since the spray test of the individual nozzles is carried out only in succession and not next to one another and a narrow spray window 28 enables a narrow design of the device and thus less overall widening of the printer chassis.
  • the write head is moved into this position, in which it is at a constant distance from the ink droplet sensor described. It is possible and advantageous for the write head to assume this position, for example in the idle state or before each start of writing or printing, and for a monitoring process to precede the start of operation. If a failure of one or more outlet nozzles is found, then a manual rinsing with a cleaning effect provided in many currently known ink-writing heads can be carried out in a short time with a cleaning effect.
  • the invention has been described above primarily with regard to its use in a printer for monitoring droplet ejection. However, it is within the scope of the invention to use the arrangement according to the invention for measuring and adjusting the flight speed of individual ink droplets. Since the distance between the exit nozzles and the surfaces of the ink droplet sensor is known, this only requires that the times of ejection and impact are detected, which e.g. is possible in the printer control without considerable electronic effort. This option offers considerable advantages, especially in the manufacture of ink-writing heads with a larger number of outlet nozzles, because in this case, because of the never completely avoidable tolerance of the individual electrical and ceramic (e.g. piezo elements) components, each one consists of a control circuit, drive element, ink channel and outlet nozzles System must be adjusted.
  • the described device for detecting ink drops is characterized by a compact, small design that is easy to use or replace in the printer; it also offers the possibility of fully automatic assembly and only requires four different components that can be created with cost-effective technology.
  • the arrangement can not only be used very advantageously in inkjet printers which work with multi-nozzle print heads, but is also suitable for economical quality assurance, since it can be used advantageously in the manufacture and long-term testing of multi-nozzle print heads.

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  • Ink Jet (AREA)
  • Particle Formation And Scattering Control In Inkjet Printers (AREA)

Abstract

Pour le contrôle des gouttes projetées par les buses de sortie d'une tête d'écriture à encre, il est prévu un détecteur de gouttes d'encre, comportant une plaque de détection (12) dont la surface, orientée vers les buses de sortie, se présente sous la forme d'une électrode interdigitale avec des voies conductrices à structure interdigitale (18, 19), qui sont disposées sur un bloc d'aspiration (17) constitué d'au moins une couche poreuse non conductrice; en fonction de la séparation dans la structure interdigitale, la résistance entre des voies conductrices voisines (18, 19) se modifie avec la projection d'une ou plusieurs gouttes; un circuit d'évaluation (20) relié aux voies conductrices (18, 19) contrôle la modification de résistance et produit un signal de détection (SM); la quantité de liquide déposée avec la projection d'une ou plusieurs gouttes est émise par capillarité (17) par l'intermédiaire de la couche poreuse du bloc d'aspiration.

Claims (15)

  1. Dispositif pour contrôler l'éjection de gouttelettes à partir de buses de sortie (3) d'une tête d'écriture à encre (1) au moyen d'un détecteur (11) des gouttelettes d'encre, qui évalue l'apparition de gouttelettes d'encre (9) et qui est disposé devant les buses de sortie (3) et qui comporte des électrodes (18,19; 181,191) structurées en forme de peigne et qui sont disposées avec un pas de répartition déterminé (T), la variation de résistance entre deux électrodes voisines (18,19; 181,191), qui apparaît lorsqu'au moins une gouttelette d'encre (9) rencontre les électrodes (18,19; 181,191), étant détectée et évaluée dans un circuit d'évaluation (20), caractérisé par le fait que le détecteur (11) des gouttelettes d'encre possède une plaque de détection (12,25), que des voies conductrices (181,191), qui possèdent une forme sinueuse et qui forment, dans la zone d'impact des gouttelettes, la structure de peigne possédant le pas de répartition (T), sont disposées selon une configuration bifilaire sur la surface tournée vers les buses de sortie (3), et que le circuit d'évaluation (29) peut être raccordé à respectivement deux bornes (13,14) des voies conductrices bifilaires (181,191), que les deux autres bornes (23,24) ne sont pas raccordées entre elles, et qu'en aval de la plaque de détection (12,25), il est prévu un bloc d'aspiration (17) qui est formé par au moins une couche poreuse non conductrice et qui sert à évacuer le liquide par capillarité.
  2. Dispositif suivant la revendication 1, caractérisé par le fait qu'une source de courant peut être raccordée à respectivement deux bornes (13,14) des voies conductrices bifilaires (181,191) pendant des pauses de mesure du circuit d'évaluation (20) et que les deux autres bornes (23,24) sont, dans ce cas, reliées entre elles.
  3. Dispositif suivant les revendications 1 et 2, caractérisé par le fait que pour le contrôle de l'impact de gouttelettes individuelles, le pas de répartition (T) de la structure de peigne est inférieur ou égal au diamètre (D) d'une gouttelette d'encre individuelle (T ≦ D).
  4. Dispositif suivant la revendication 1 ou 2, caractérisé par le fait que pour le contrôle de l'impact de plusieurs gouttelettes individuel les éjectées successivement hors d'une buse respective de sortie (3), le pas de répartition (T) de la structure en peigne est supérieur au diamètre (D) d'une gouttelette d'encre individuelle (T > D).
  5. Dispositif suivant la revendication 1, caractérisé par le fait que le bloc d'aspiration (17) est réalisé en un matériau non conducteur, apte à réaliser une aspiration.
  6. Dispositif suivant la revendication 1, caractérisé par le fait que le bloc d'aspiration (17) est constitué par au moins deux couches partielles (15,16) réalisées en un matériau non conducteur et à pouvoir absorbant et qui possèdent des porosités différentes et une même épaisseur ou des épaisseurs différentes, et que la porosité des différentes couches (15,16) augmente lorsque la distance par rapport au peigne d'électrodes augmente (P2 > P1).
  7. Dispositif suivant l'une des revendications 1 à 4, caractérisé par le fait que les voies conductrices (18, 19; 181,191) et les éléments de peigne (121,122) sont formés par des électrodes sur une feuille isolante (21) qui est déposée sur le bloc d'aspiration (17;15,16) et est structurée en fonction du pas de répartition (T).
  8. Dispositif suivant les revendications 1 à 4, caractérisé par le fait que les voies conductrices (18,19) et les éléments de peigne (121,122) de la plaque de détection (12,25) sont formés sur une plaque de support (26), respectivement au moins une fenêtre de contact (27) étant prévue sur les éléments de peigne (121,122), et une fenêtre de projection (28) étant prévue dans la zone d'impact des gouttelettes,
    qu'il est prévu un boitier (29) servant à bloquer le bloc d'aspiration (17) et la plaque de détection (12,25) recouvrant le bloc d'aspiration (17), et
    qu'il est prévu des éléments de fixation (42), qui relient mécaniquement de façon sûre la plaque de détection (12,25) au bloc d'aspiration (17) et établissent également un contact électrique avec la plaque de détection (12,25), par l'intermédiaire des fenêtres de contact (27).
  9. Dispositif suivant la revendication 8, caractérisé par le fait que le boîtier (29) possède des languettes d'encliquetage élastiques latérales (40), à l'aide desquelles il est fixé de façon amovible au châssis (41) d'une imprimante.
  10. Dispositif suivant la revendication 9, caractérisé par le fait que le boîtier (29) est fixé au châssis de l'imprimante (41) en dehors de la zone d'impression, de préférence sur le bord gauche ou droit des lignes de la zone d'impression.
  11. Dispositif suivant la revendication 8, caractérisé par le fait qu'une zone de réception (48) pour une évacuation supplémentaire de l'encre est prévue dans le boîtier (29) au-dessous du bloc d'aspiration (17).
  12. Dispositif suivant la revendication 8, caractérisé par le fait que les éléments de fixation (42) sont des ressorts de contact, qui sont disposés des deux côtés du boîtier (29) et dont les ergots d'encliquetage (44) s'encliquettent dans un évidement (45) du boîtier (29) lors de l'introduction des ressorts de contact (42) dans ce boîtier et dont les languettes élastiques (46) saisissent sous pression la surface de la plaque de détection (12,25), au moins un ressort de contact étant disposé de chaque côté du boîtier (29) dans la zone de la fenêtre de contact (27).
  13. Dispositif suivant la revendication 12, caractérisé par le fait que les parties ressorties des ressorts de contact (42) sont réalisées sous la forme d'une borne de connecteur.
  14. Dispositif suivant la revendication 1, caractérisé par le fait que le circuit d'évaluation (20) comporte un circuit diviseur de tension, qui est constitué par une résistance fixe (30) et la résistance (31) située entre les bornes (13,14) des voies conductrices (18,19; 181,191) et est raccordée à une source de tension continue (+U), un comparateur (32) raccordé au point de division du circuit diviseur de tension et une bascule bistable (37) commandable par l'intermédiaire de la sortie du comparateur, la valeur de tension (Um), qui s'établit au niveau du point de division du circuit diviseur de tension (30,31), étant appliquée directement à une entrée tandis qu'une valeur moyenne dans le temps (Umm) formée par un circuit intégrateur (35,36) est appliquée à l'autre entrée du comparateur (32), au moyen de la sortie duquel la commande du circuit bistable (37) est inversée en fonction d'une variation de résistance entre les bornes (13,14) et qui délivre le signal de détection (SM), et qu'après évaluation du signal de détection (SM), le circuit bistable (37) est à nouveau ramené à l'état initial.
  15. Dispositif suivant la revendication 1, caractérisé par le fait que le circuit d'évaluation (20) comporte un circuit diviseur de tension constitué par une résistance fixe (30) et la résistance (31) présente entre les bornes (13,14) des voies conductrices (18,19; 181,191) et est raccordé à un générateur de tension alternative (38), et un circuit démodulateur (33) raccordé au point de division du circuit diviseur de tension (30,31), que la sortie du circuit démodulateur (33) est, d'une part, raccordée directement à une entrée, et, d'autre part, et par l'intermédiaire d'un circuit intégrateur (35,36), à l'autre entrée du comparateur (32), par l'intermédiaire de la sortie duquel le circuit bistable (37) est commuté en fonction d'une variation de résistance entre les bornes (13,14) et qui délivre le signal de détection (SM) et qu'après évaluation du signal de détection (SM), le circuit bistable (37) est à nouveau ramené à l'état initial.
EP88907604A 1987-09-25 1988-09-09 Dispositif pour controler la projection de gouttes par les buses de sortie d'unetete d'ecriture a encre Expired - Lifetime EP0382741B1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE3732396 1987-09-25
DE19873732395 DE3732395A1 (de) 1987-09-25 1987-09-25 Verfahren und anordnung zur ueberwachung des troepfchenausstosses aus austrittsduesen eines tintenschreibkopfes
DE3732395 1987-09-25
DE19873732396 DE3732396A1 (de) 1987-09-25 1987-09-25 Vorrichtung zur ueberwachung des troepfchenausstosses aus austrittsduesen eines tintenschreibkopfes

Publications (2)

Publication Number Publication Date
EP0382741A1 EP0382741A1 (fr) 1990-08-22
EP0382741B1 true EP0382741B1 (fr) 1993-11-24

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Application Number Title Priority Date Filing Date
EP88907604A Expired - Lifetime EP0382741B1 (fr) 1987-09-25 1988-09-09 Dispositif pour controler la projection de gouttes par les buses de sortie d'unetete d'ecriture a encre
EP88907627A Expired - Lifetime EP0389481B1 (fr) 1987-09-25 1988-09-20 Procede et dispositif pour verifier automatiquement l'aptitude au fonctionnement de systemes d'impression a encre
EP88908144A Ceased EP0380526A1 (fr) 1987-09-25 1988-09-26 Procede et dispositif pour determiner la position d'impression des ajutages de sortie dans des tetes d'impression a encre

Family Applications After (2)

Application Number Title Priority Date Filing Date
EP88907627A Expired - Lifetime EP0389481B1 (fr) 1987-09-25 1988-09-20 Procede et dispositif pour verifier automatiquement l'aptitude au fonctionnement de systemes d'impression a encre
EP88908144A Ceased EP0380526A1 (fr) 1987-09-25 1988-09-26 Procede et dispositif pour determiner la position d'impression des ajutages de sortie dans des tetes d'impression a encre

Country Status (4)

Country Link
EP (3) EP0382741B1 (fr)
JP (3) JPH03500271A (fr)
DE (2) DE3885904D1 (fr)
WO (3) WO1989002826A1 (fr)

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DE69123615T2 (de) * 1990-02-23 1997-04-24 Canon Kk Bildübertragungsgerät
US5160938A (en) * 1990-08-06 1992-11-03 Iris Graphics, Inc. Method and means for calibrating an ink jet printer
JP3190486B2 (ja) * 1993-07-19 2001-07-23 キヤノン株式会社 インクジェット記録装置および該装置用インクジェット記録ヘッド
JP2000270129A (ja) * 1999-03-12 2000-09-29 Ryuji Ito インクジェット式プリンタを備えた印画装置
DE10027261B4 (de) 1999-06-28 2017-04-27 Heidelberger Druckmaschinen Ag Verfahren und Vorrichtung zum Reinigen einer Düsenaustrittsfläche an einem Druckkopf eines Tintenstrahldruckers
DE10028318B4 (de) 1999-06-28 2017-02-16 Heidelberger Druckmaschinen Ag Verfahren und Vorrichtung zur Reinigung eines Druckkopfes eines Tintenstrahldruckers
WO2002053386A1 (fr) * 2000-12-29 2002-07-11 Array Ab Procede et dispositif d'impression electrostatique directe
EP1245397B1 (fr) * 2001-03-30 2006-06-28 Hewlett-Packard Company, A Delaware Corporation Appareil et procédé de détection de gouttes d'encre dans un dispositif d'impression
EP1245399B1 (fr) 2001-03-30 2010-03-03 Hewlett-Packard Company, A Delaware Corporation Méthode d'alignement améliorée pour dispositif d'impression et appareil correspondant
JP5564893B2 (ja) * 2009-10-29 2014-08-06 コニカミノルタ株式会社 インクジェット記録装置
WO2012084686A1 (fr) 2010-12-21 2012-06-28 Oce-Technologies B.V. Procédé pour déterminer des performances d'unité de maintenance
JP6232861B2 (ja) * 2013-09-04 2017-11-22 株式会社リコー 画像形成装置及び吐出検知装置
JP7224906B2 (ja) * 2018-01-12 2023-02-20 キヤノン株式会社 モジュール基板の洗浄方法
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Also Published As

Publication number Publication date
WO1989002827A1 (fr) 1989-04-06
DE3885904D1 (de) 1994-01-05
JPH03500272A (ja) 1991-01-24
WO1989002826A1 (fr) 1989-04-06
EP0380526A1 (fr) 1990-08-08
JPH03500270A (ja) 1991-01-24
WO1989002828A1 (fr) 1989-04-06
EP0389481A1 (fr) 1990-10-03
EP0389481B1 (fr) 1994-03-09
EP0382741A1 (fr) 1990-08-22
JPH03500271A (ja) 1991-01-24
DE3888363D1 (de) 1994-04-14

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