EP0124465B1 - Charge control device and its application to ink droplets speed control. - Google Patents
Charge control device and its application to ink droplets speed control. Download PDFInfo
- Publication number
- EP0124465B1 EP0124465B1 EP84460003A EP84460003A EP0124465B1 EP 0124465 B1 EP0124465 B1 EP 0124465B1 EP 84460003 A EP84460003 A EP 84460003A EP 84460003 A EP84460003 A EP 84460003A EP 0124465 B1 EP0124465 B1 EP 0124465B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- charge
- drops
- ink drops
- speed
- passage
- 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
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
- B41J2/07—Ink jet characterised by jet control
- B41J2/125—Sensors, e.g. deflection sensors
Definitions
- the invention relates to a device for controlling the charge of drops in an ink jet printer, as well as its application to controlling the speed of said drops.
- the ink-jet writing technique using a continuous jet of calibrated droplets, supplied by a modulation system, requires electrostatically charging these droplets by means of an appropriate electrode.
- the passage of these variably charged drops between plates brought to a high potential leads to a deflection of the drops proportional to the charge and which, combined with the displacement of a support, makes it possible to obtain matrices of printed characters.
- the proper functioning of the device requires the introduction of means for controlling the accuracy of the charge and the speed of the drops. These must meet a certain number of requirements, the main ones being in particular the small size and the great rusticity.
- the device must not be able to be out of balance, nor be altered by the chemically aggressive environment. Finally, it must be effective and for this it must not risk being disturbed by the neighboring electric fields.
- each device alone performs only one function, charge control or measurement of the speed of the drops.
- the present invention specifically relates to a device capable of controlling both the charge and the speed of the drops in an inkjet printer simple and easy to set up. More precisely, it relates to a device for controlling the charge of ink drops fragmented and electrostatically charged in order to be deflected to constitute a matrix of characters printed on a support, comprising a charge detector placed inside a cylinder.
- this detector load consists of two full cylinders (31) and (32), the slit being formed so that the drops pass successively through the first and second conductors (31) and (32) split, inducing at each of these two passages, a signal operated by an electronic circuit (12).
- the invention also relates to the application of this charge control device for controlling the speed of drops of an ink jet.
- a certain number of operating parameters must be preserved despite the inevitable variations in the environment. This is the case in particular of the speed of the drops: this must be kept constant despite the modifications of the characteristics of the ink such as the viscosity which can change over time.
- the viscosity which can change over time.
- evaporation of the solvent occurs in the more or less long term. This results in a concomitant change in viscosity and therefore speed.
- the present invention therefore also aims to overcome these drawbacks and relates to a method for measuring the speed of the ink drops to control the means for pressurizing the ink to the time (T) that each drop takes to travel a distance (D); this distance being obtained thanks to the use of a charge control device, in accordance with the invention.
- this outer cylinder (1) constituting the shielding of the device (100), is filled over a certain length by an insulating material (2 1 ), for example a fluoropolymer such as a PTFE.
- an insulating material (2 1 ) for example a fluoropolymer such as a PTFE.
- two holes are drilled in the insulating sheath (2 1 ), holes in which are introduced two solid cylinders (3 1 ) and (3 2 ) which are embedded in the insulating sheath (2).
- a slot (10) is made over a length (L) and a thickness (e).
- the cylinders (3 1 ) and (3 2 ) are both connected to an electronic control circuit (not shown in Figures 1 a and 1 b).
- Such a structure makes it possible to carry out two successive measurements of the charge of the drops which pass through the slot, one at the level of the full cylinder (3 1 ) and the other, at the level of the full cylinder (3 2 ).
- FIG. 2 A nonlimiting exemplary embodiment of an electronic circuit (12) intended to cooperate with a device according to the invention is shown diagrammatically in FIG. 2.
- the detector (100) consisting of its external shield (1 grounded (m) and its slot (10), is connected by a coaxial tube (11) to the inlet (E) of the circuit (12). It has four essential parts, the first (A) which consists of the combination of a resistor (R1) and two diodes (d1) and (d2) of reverse polarity, has the function of protecting the device against overvoltages accidental from the presence of high voltages on the detector (100); the second (B) is a bandpass filter consisting of a high gain amplifier (A1-R5-C2).
- the positive input of the latter is connected to a resistor (R1) itself connected to ground while its negative input is also connected to ground (m) through the resistor (R4) and the parallel resistor / capacitor circuit. (R3-C1).
- the signal at the output of the amplifier (A1) is applied to a hysteresis comparator (D) through a cell (C) constituted by a capacitor (C3) and a resistor (R6) whose function is to block the passage continuous voltages;
- this hysteresis comparator consisting of an amplifier (A2), two resistors (R7) and (R8) and a potentiometer (P1), supplies the output (S) of the electronic circuit (12) with a logic signal usable by control means of known type, capable of measuring the amplitude of the signal present at the output (S).
- Such a charge control electrode can also perform a second function; namely that of a device for measuring and controlling the speed of the ink drops as explained below.
- the pressurization of the ink in the printer is ensured by means of a gear pump of a type known per se controlled by a stepping motor. It is precisely the qualities of these means of pressurization that are used in the present invention to, according to an important characteristic, reduce the speed of each drop to a constant value by varying the pressure as a function of precisely the evolution of this speed.
- the method according to the invention therefore consists in continuously measuring the speed of the drops and in controlling this data, the operation of the pressurizing pump.
- It implements a charge control electrode of the type which is described by means of FIGS. 1a and 1b.
- a charge control electrode of the type which is described by means of FIGS. 1a and 1b.
- Such a structure makes it possible to carry out two successive measurements of the charge of the drops which pass through the slot, one at level of the full cylinder (30) and the other, at the level of the full cylinder (31), in accordance with the present invention, it is also used to detect two instants of passage (t) and (t1) of each drop at the level of each of the two full cylinders (30) and (31). In this case, the distance (D) between the two electrodes is determined and fixed by construction.
- the "time” parameter (T) being thus measured in accordance with the invention, the supply frequency of the stepping motors which control the pressurizing pumps is varied in order to keep this time (T) constant.
- the process according to the invention applies to all inkjet printheads. carrying a charge electrode and at least one charge control electrode and means capable of varying the pressure of the ink, this variation in pressure is controlled by sigmals taken from the electronic circuits controlling the charge of the droplets and the control of this charge.
- a charge control device proves to be very effective for measuring drop charges not exceeding a few picocoulombs. It is intended to equip the printheads for inkjet printers.
- the realization of the slot (10) is preferably carried out when the detector is already positioned in the print head. Thus its centering can be optimized, which increases the reliability of the device.
- the invention applies to all inkjet printers.
Landscapes
- Particle Formation And Scattering Control In Inkjet Printers (AREA)
Description
L'invention concerne un dispositif de contrôle de charge des gouttes dans une imprimante à jet d'encre, ainsi que son application au contrôle de la vitesse des dites gouttes.The invention relates to a device for controlling the charge of drops in an ink jet printer, as well as its application to controlling the speed of said drops.
La technique d'écriture par projection d'encre utilisant un jet continu de gouttelettes calibrées, fournies par un système de modulation, nécessite de charger électrostatiquement ces gouttelettes au moyen d'une électrode appropriée. Le passage de ces gouttes chargées de manière variable entre des plaques portées à un fort potentiel conduit à une déflexion des gouttes proportionnelles à la charge et qui, combinée avec le déplacement d'un support, permet l'obtention de matrices de caractères imprimés.The ink-jet writing technique using a continuous jet of calibrated droplets, supplied by a modulation system, requires electrostatically charging these droplets by means of an appropriate electrode. The passage of these variably charged drops between plates brought to a high potential leads to a deflection of the drops proportional to the charge and which, combined with the displacement of a support, makes it possible to obtain matrices of printed characters.
Le bon fonctionnement du dispositif exige l'introduction de moyens de contrôle de la précision de la charge et de la vitesse des gouttes. Ceuxci doivent répondre à un certain nombre d'exigences dont les principales sont notamment le faible encombrement et la grande rusticité. Le dispositif ne doit pas pouvoir se dérégler, ni être altéré par l'environnement chimiquement agressif. Enfin, il doit être efficace et pour cela il ne doit pas risquer d'être perturbé par les champs électriques avoisinants.The proper functioning of the device requires the introduction of means for controlling the accuracy of the charge and the speed of the drops. These must meet a certain number of requirements, the main ones being in particular the small size and the great rusticity. The device must not be able to be out of balance, nor be altered by the chemically aggressive environment. Finally, it must be effective and for this it must not risk being disturbed by the neighboring electric fields.
Le brevet US 3.977.010 (Fig. 6) decrit un dispositif dans lequel deux noyaux conducteurs sont noyés dans un cylindre en matériau isolant de part et d'autre d'une fente réalisée dans le dit cylindre. La mise en oeuvre d'un tel dispositif n'est ni simple, ni fiable car des problèmes d'alignement des conducteurs se posent au niveau du passage des gouttes.US Patent 3,977,010 (Fig. 6) describes a device in which two conductive cores are embedded in a cylinder of insulating material on either side of a slot made in said cylinder. The implementation of such a device is neither simple nor reliable because alignment problems of the conductors arise at the level of the passage of the drops.
Le brevet US 3.852.768 (voir c, 3, t. 5 10) decrit un procédé de mesure de la vitesse des gouttes nécessitant la mise en oeuvre de deux détecteurs individuels placés à une distance déterminée.US Pat. No. 3,852,768 (see c, 3, t. 5 10) describes a method for measuring the speed of the drops requiring the use of two individual detectors placed at a determined distance.
Dans les deux cas, chacun des dispositifs n'accomplit lui seul qu'une seulefonction, le contrôle de charge ou la mesure de la vitesse des gouttes.In both cases, each device alone performs only one function, charge control or measurement of the speed of the drops.
La présente invention a précisément pour objet un dispositif capable de contrôler à la fois la charge et la vitesse des gouttes dans une imprimante à jet d'encre simple et facile à mettre en place. Elle concerne plus précisément un dispositif de contrôle de charge de gouttes d'encre fragmentées et chargées électrostatiquement en vue d'être déviées pour constituer une matrice de caractères imprimés sur un support, comportant un détecteur de charge placé à l'intérieur d'un cylindre creux extérieur conducteur (1) et isolé de ce cylindre extérieur (1) par un cylindre intermédiaire isolant (2), une fente étant pratiquée dans cet ensemble pour permettre le passage des gouttes d'encre chargées, dispositif caractérisé en ce que ce détecteur de charge est constitué de deux cylindres pleins (31) et (32), la fente étant pratiquée de telle sorte que les gouttes passent successivement à travers le premier et le second conducteurs (31) et (32) fendus, induisant au niveau de chacun de ces deux passages, un signal exploité par un circuit électronique (12).The present invention specifically relates to a device capable of controlling both the charge and the speed of the drops in an inkjet printer simple and easy to set up. More precisely, it relates to a device for controlling the charge of ink drops fragmented and electrostatically charged in order to be deflected to constitute a matrix of characters printed on a support, comprising a charge detector placed inside a cylinder. conductive external hollow (1) and isolated from this external cylinder (1) by an insulating intermediate cylinder (2), a slot being formed in this assembly to allow the passage of charged ink drops, device characterized in that this detector load consists of two full cylinders (31) and (32), the slit being formed so that the drops pass successively through the first and second conductors (31) and (32) split, inducing at each of these two passages, a signal operated by an electronic circuit (12).
L'invention concerne également l'application de ce dispositif de contrôle de charge, au contrôle de la vitesse de gouttes d'un jet d'encre. En effet, dans une imprimante à jet d'encre, un certain nombre de paramètres de fonctionnement doivent être conservés malgré les variations inévitables d'environnement. C'est le cas notamment de la vitesse des gouttes: celleci doit être maintenue constante malgré les modifications des caractéristiques de l'encre comme la viscosité qui peut évoluer au cours du temps. En effet, sous l'influence des variations de la température ambiante, ou suite à des conditions de fonctionnement générant un surcroît d'échauffement, une évaporation du solvant intervient à plus ou moins long terme. Il en résulte une évolution concommitante de la viscosité donc de la vitesse. La présente invention a donc également comme but de pallier ces inconvénients et concerne un procédé de mesure de la vitesse des gouttes d'encre pour asservir les moyens de mise en pression de l'encre au temps (T) que met chaque goutte pour parcourir une distance (D); cette distance étant obtenue grâce à la mise en oeuvre d'un dispositif de contrôle de charge, conforme à l'invention.The invention also relates to the application of this charge control device for controlling the speed of drops of an ink jet. Indeed, in an inkjet printer, a certain number of operating parameters must be preserved despite the inevitable variations in the environment. This is the case in particular of the speed of the drops: this must be kept constant despite the modifications of the characteristics of the ink such as the viscosity which can change over time. In fact, under the influence of variations in the ambient temperature, or following operating conditions generating an increase in heating, evaporation of the solvent occurs in the more or less long term. This results in a concomitant change in viscosity and therefore speed. The present invention therefore also aims to overcome these drawbacks and relates to a method for measuring the speed of the ink drops to control the means for pressurizing the ink to the time (T) that each drop takes to travel a distance (D); this distance being obtained thanks to the use of a charge control device, in accordance with the invention.
L'invention sera mieux comprise à l'aide des explications qui vont suivre et des figures jointes parmi lesquelles:
- - les figures 1 a et 1 b représentent schématiquement, vu de face, selon une coupe (AA) et une coupe (BB), un exemple de réalisation d'un dispositif conforme à l'invention;
- - la figure 2 est une représentation schématique d'un circuit électronique destiné à coopérer avec un dispositif selon l'invention pour la mesure de la charge des gouttes.
- - Figures 1a and 1b show schematically, seen from the front, in a section (AA) and a section (BB), an embodiment of a device according to the invention;
- - Figure 2 is a schematic representation of an electronic circuit intended to cooperate with a device according to the invention for measuring the charge of the drops.
Pour plus de clarté, les mêmes éléments portent les mêmes références sur toutes les figures.For clarity, the same elements are given the same references in all the figures.
Selon les figures 1a et 1b deux électrodes de contrôle de charge sont insérées dans un cylindre (1) unique en matériau conducteur.According to Figures 1a and 1b two charge control electrodes are inserted into a single cylinder (1) of conductive material.
L'intérieur de ce cylindre extérieur (1), constituant le blindage du dispositif (100), est rempli sur une certaine longueur par un matériau isolant (21), par exemple un polymère fluoré tel qu'un PTFE. Selon une caractéristique de l'invention, deux trous sont percés dans le fourreau isolant (21), trous dans lequels sont introduits deux cylindres pleins (31) et (32) qui se trouvent noyés dans le fourreau isolant (2). Enfin, une fente (10) est réalisée sur une longueur (L) et une épaisseur (e). Les cylindres (31) et (32) sont l'un et l'autre reliés à un circuit électronique de commande (non représentés sur les figures 1 a et 1 b). Une telle structure permet d'effectuer deux mesures successives de la charge des gouttes qui transitent dans la fente, l'une au niveau du cylindre plein (31) et l'autre, au niveau du cylindre plein (32).The interior of this outer cylinder (1), constituting the shielding of the device (100), is filled over a certain length by an insulating material (2 1 ), for example a fluoropolymer such as a PTFE. According to a characteristic of the invention, two holes are drilled in the insulating sheath (2 1 ), holes in which are introduced two solid cylinders (3 1 ) and (3 2 ) which are embedded in the insulating sheath (2). Finally, a slot (10) is made over a length (L) and a thickness (e). The cylinders (3 1 ) and (3 2 ) are both connected to an electronic control circuit (not shown in Figures 1 a and 1 b). Such a structure makes it possible to carry out two successive measurements of the charge of the drops which pass through the slot, one at the level of the full cylinder (3 1 ) and the other, at the level of the full cylinder (3 2 ).
Un exemple de réalisation non limitatif d'un circuit électronique (12) destiné à coopérer avec un dispositif conforme à l'invention est représenté schématiquement sur la figure 2.A nonlimiting exemplary embodiment of an electronic circuit (12) intended to cooperate with a device according to the invention is shown diagrammatically in FIG. 2.
Le détecteur (100) constitué de son blindage extérieur (1 mis à la masse (m) et de sa fente (10), est relié par un tube coaxial (11) à l'entrée (E) du circuit (12). Celui-ci comporte quatre parties essentielles, la première (A) qui est constituée par la combinaison d'une résistance (R1) et deux diodes (d1) et (d2) de polarité inversée, a pour fonction de protéger le dispositif contre des surtensions accidentelles provenant de la présence de hautes tensions sur le détecteur (100); la seconde (B) est un filtre passe-bande constitué par un amplificateur (A1-R5-C2) à gain élevé.The detector (100) consisting of its external shield (1 grounded (m) and its slot (10), is connected by a coaxial tube (11) to the inlet (E) of the circuit (12). It has four essential parts, the first (A) which consists of the combination of a resistor (R1) and two diodes (d1) and (d2) of reverse polarity, has the function of protecting the device against overvoltages accidental from the presence of high voltages on the detector (100); the second (B) is a bandpass filter consisting of a high gain amplifier (A1-R5-C2).
L'entrée positive de ce dernier est reliée à une résistance (R1) reliée elle-même à la masse tandis que son entrée négative est reliée également à la masse (m) à travers la résistance (R4) et le circuit parallèle résistance/condensateur (R3-C1).The positive input of the latter is connected to a resistor (R1) itself connected to ground while its negative input is also connected to ground (m) through the resistor (R4) and the parallel resistor / capacitor circuit. (R3-C1).
Le signal à la sortie de l'amplificateur (A1) est appliqué à un comparateur à hysteresis (D) à travers une cellule (C) constituée par un condensateur (C3) et une résistance (R6) dont la fonction est de bloquer le passage des tensions continues; ce comparateur à hysteresis constitué par un amplificateur (A2), deux résistances (R7) et (R8) et un potentiomètre (P1), fournit à la sortie (S) du circuit électronique (12) un signal logique utilisable par des moyens de contrôle de type connu, capables de mesurer l'amplitude du signal présent à la sortie (S).The signal at the output of the amplifier (A1) is applied to a hysteresis comparator (D) through a cell (C) constituted by a capacitor (C3) and a resistor (R6) whose function is to block the passage continuous voltages; this hysteresis comparator consisting of an amplifier (A2), two resistors (R7) and (R8) and a potentiometer (P1), supplies the output (S) of the electronic circuit (12) with a logic signal usable by control means of known type, capable of measuring the amplitude of the signal present at the output (S).
Une telle électrode de contrôle de charge peut également accomplir une seconde fonction; à savoir celle de dispositif de mesure et de contrôle de la vitesse des gouttes d'encre comme cela est expliqué ci-après.Such a charge control electrode can also perform a second function; namely that of a device for measuring and controlling the speed of the ink drops as explained below.
Une imprimante à jet d'encre est essentiellement constituée de manière classique:
- -d'un réservoir d'encre,
- -d'une pompe de mise en pression de cette encre,
- -d'un transducteur piezo-électrique chargé de fractionner le jet,
- -d'une électrode de charge,
- -d'une électrode de contrôle de charge,
- -de plaques de déflexion.
- -an ink tank,
- a pump for pressurizing this ink,
- -a piezoelectric transducer responsible for fractionating the jet,
- -a charging electrode,
- -a charge control electrode,
- -deflection plates.
Conformément à l'invention, la mise en pression de l'encre dans l'imprimante est assurée au moyen d'une pompe à engrenage d'un type connu en soi commandé par un moteur pas à pas. Ce sont précisément les qualités de ces moyens de _mise en pression que l'on utilise dans la présente invention pour, selon une caractéristique importante, ramener la vitesse de chaque goutte à une valeur constante en faisant varier la pression en fonction précisément de l'évolution de cette vitesse.According to the invention, the pressurization of the ink in the printer is ensured by means of a gear pump of a type known per se controlled by a stepping motor. It is precisely the qualities of these means of pressurization that are used in the present invention to, according to an important characteristic, reduce the speed of each drop to a constant value by varying the pressure as a function of precisely the evolution of this speed.
Le procédé conforme à l'invention consiste donc à mesurer en permanence la vitesse des gouttes et à asservir à cette donnée, le fonctionnement de la pompe de mise en pression.The method according to the invention therefore consists in continuously measuring the speed of the drops and in controlling this data, the operation of the pressurizing pump.
Il met en oeuvre une électrode de contrôle de charge du type de celui qui est décrit au moyen des figures la et Ib. Une telle structure permet d'effectuer deux mesures successives de la charge des gouttes qui transitent dans la fente, l'une au niveau du cylindre plein (30) et l'autre, au niveau du cylindre plein (31), conformément à la présente invention, elle est en outre utilisée pour détecter deux instants de passage (t) et (t1) de chaque goutte au niveau de chacun des deux cylindres pleins (30) et (31). Dans ce cas, la distance (D) entre les deux électrodes est déterminée et fixée par construction.It implements a charge control electrode of the type which is described by means of FIGS. 1a and 1b. Such a structure makes it possible to carry out two successive measurements of the charge of the drops which pass through the slot, one at level of the full cylinder (30) and the other, at the level of the full cylinder (31), in accordance with the present invention, it is also used to detect two instants of passage (t) and (t1) of each drop at the level of each of the two full cylinders (30) and (31). In this case, the distance (D) between the two electrodes is determined and fixed by construction.
La mesure de ces deux charges faite dans le cadre du contrôle de cellesci permet conformément à l'invention d'être exploitée dans un second but. Elle permet en effet la détection des deux temps de passage (t) et (t1), donc la mesure du temps (T = t1 - t) qu'a mis la goutte pour parcourir la distance (D) entre l'axe des deux cylindres (30) et (31) et ce faisant, elle permet de connaître la vitesse de chacune des gouttes.The measurement of these two charges made as part of the control thereof allows according to the invention to be used for a second purpose. It indeed allows the detection of the two passage times (t) and (t1), therefore the measurement of the time (T = t1 - t) that the drop took to travel the distance (D) between the axis of the two cylinders (30) and (31) and in so doing, it makes it possible to know the speed of each of the drops.
Le paramètre "temps" (T) étant ainsi mesuré conformément à l'invention, on fait varier la fréquence d'alimentation des moteurs pas à pas qui commamdent les pompes de mise en pression afin de conserver ce temps (T) constant.The "time" parameter (T) being thus measured in accordance with the invention, the supply frequency of the stepping motors which control the pressurizing pumps is varied in order to keep this time (T) constant.
Le procédé conforme à l'invention s'applique à toutes les têtes d'impression à jet d'encre com- . portant une électrode de charge et au moins une électrode de contrôle de charge et des moyens capables de faire varier la pression de l'encre, cette variation de pression étamt commandée par des sigmaux prélevés au niveau des circuits électroniques commandant la charge des gouttelettes et le contrôle de cette charge.The process according to the invention applies to all inkjet printheads. carrying a charge electrode and at least one charge control electrode and means capable of varying the pressure of the ink, this variation in pressure is controlled by sigmals taken from the electronic circuits controlling the charge of the droplets and the control of this charge.
Dans ces conditions, on dispose d'une machine absolument autonome quel que soit l'âge de l'encre, la durée journalière de fonctionnement et la température ambiante.Under these conditions, an absolutely autonomous machine is available regardless of the age of the ink, the daily operating time and the ambient temperature.
A un tel dispositif, on peut d'ailleurs aussi associer un système d'alarme fonctionnant lorsque la pression se situe à l'extérieur d'une plage de valeurs pré-déterminées.With such a device, it is also possible to associate an alarm system operating when the pressure is outside a range of predetermined values.
Un dispositif de contrôle de charge conforme à l'invention et tel qu'il vient d'être décrit s'avère très efficace pour mesurer des charges de gouttes n'excédant pas quelques picocoulombs. Il est destiné à équiper les têtes d'impression pour imprimante à jet d'encre. La réalisation de la fente (10) est de préférence réalisée lorsque le détecteur est déjà positionné dans la tête d'impression. Ainsi son centrage peut être optimisé, ce qui accroît la fiabilité du dispositif.A charge control device according to the invention and as described above proves to be very effective for measuring drop charges not exceeding a few picocoulombs. It is intended to equip the printheads for inkjet printers. The realization of the slot (10) is preferably carried out when the detector is already positioned in the print head. Thus its centering can be optimized, which increases the reliability of the device.
L'invention s'applique à toutes les imprimantes àjet d'encre.The invention applies to all inkjet printers.
Claims (2)
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8307549 | 1983-04-29 | ||
| FR8307549A FR2545041B1 (en) | 1983-04-29 | 1983-04-29 | DROP LOAD CONTROL DEVICE AND INK SPRAY PRINTER HEAD PROVIDED WITH THE SAME |
| FR8316439 | 1983-10-13 | ||
| FR8316439A FR2553339B3 (en) | 1983-10-13 | 1983-10-13 | METHOD FOR CONTROLLING THE SPEED OF INK DROPS OF AN INK JET PRINTER, AND PRINTING HEAD FOR IMPLEMENTING THE METHOD |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0124465A1 EP0124465A1 (en) | 1984-11-07 |
| EP0124465B1 true EP0124465B1 (en) | 1988-10-26 |
Family
ID=26223421
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP84460003A Expired EP0124465B1 (en) | 1983-04-29 | 1984-04-25 | Charge control device and its application to ink droplets speed control. |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US4590483A (en) |
| EP (1) | EP0124465B1 (en) |
| DE (1) | DE3474792D1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4688047A (en) * | 1986-08-21 | 1987-08-18 | Eastman Kodak Company | Method and apparatus for sensing satellite ink drop charge and adjusting ink pressure |
| US5517216A (en) * | 1992-07-28 | 1996-05-14 | Videojet Systems International, Inc. | Ink jet printer employing time of flight control system for ink jet printers |
| US5969733A (en) * | 1996-10-21 | 1999-10-19 | Jemtex Ink Jet Printing Ltd. | Apparatus and method for multi-jet generation of high viscosity fluid and channel construction particularly useful therein |
| US6003980A (en) * | 1997-03-28 | 1999-12-21 | Jemtex Ink Jet Printing Ltd. | Continuous ink jet printing apparatus and method including self-testing for printing errors |
| US6767088B2 (en) | 2001-07-16 | 2004-07-27 | Hewlett-Packard Development Company, L.P. | Methods and systems for detecting and determining trajectories of ink droplets |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3836912A (en) * | 1972-12-11 | 1974-09-17 | Ibm | Drop charge sensing apparatus for an ink jet printing system |
| JPS5421093B2 (en) * | 1973-03-12 | 1979-07-27 | ||
| JPS5230214B2 (en) * | 1973-03-12 | 1977-08-06 | ||
| US3852768A (en) * | 1973-08-17 | 1974-12-03 | Ibm | Charge detection for ink jet printers |
| US3977010A (en) * | 1975-12-22 | 1976-08-24 | International Business Machines Corporation | Dual sensor for multi-nozzle ink jet |
| US4045770A (en) * | 1976-11-11 | 1977-08-30 | International Business Machines Corporation | Method and apparatus for adjusting the velocity of ink drops in an ink jet printer |
| US4063252A (en) * | 1976-11-11 | 1977-12-13 | International Business Machines Corporation | Method and apparatus for controlling the velocity of ink drops in an ink jet printer |
| CA1158706A (en) * | 1979-12-07 | 1983-12-13 | Carl H. Hertz | Method and apparatus for controlling the electric charge on droplets and ink jet recorder incorporating the same |
| JPS56154069A (en) * | 1980-04-30 | 1981-11-28 | Sharp Corp | Detecting device for amount of electrification of ink particle in ink-jet printer |
| US4417256A (en) * | 1980-05-09 | 1983-11-22 | International Business Machines Corporation | Break-off uniformity maintenance |
| US4470052A (en) * | 1981-04-10 | 1984-09-04 | Recognition Equipment Incorporated | A-C Coupled, modulator based, phase-error sensing for IJP |
| US4460905A (en) * | 1982-03-29 | 1984-07-17 | Ncr Corporation | Control valve for ink jet nozzles |
-
1984
- 1984-04-23 US US06/603,127 patent/US4590483A/en not_active Expired - Fee Related
- 1984-04-25 DE DE8484460003T patent/DE3474792D1/en not_active Expired
- 1984-04-25 EP EP84460003A patent/EP0124465B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US4590483A (en) | 1986-05-20 |
| EP0124465A1 (en) | 1984-11-07 |
| DE3474792D1 (en) | 1988-12-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0048689B1 (en) | Quartz thermometer | |
| FR2500195A1 (en) | ELECTROSTATIC PRINTING APPARATUS | |
| EP1068510B1 (en) | Method for wavelength calibration of an electromagnetic radiation filtering device | |
| EP0362101A1 (en) | Ink controlling and regulating device for a continuous ink jet printer | |
| EP0077739B1 (en) | Apparatus to measure the ionic current produced by an ion beam | |
| EP0613012B1 (en) | Capacitive accelerometer with circuit for correcting the disturbing effects of parasitic capacitances | |
| FR2948602A1 (en) | DEVICE FOR DETECTING DIRECTIVITY OF LIQUID JET DROPPER PATHWAYS, ELECTROSTATIC SENSOR, PRINT HEAD, AND ASSOCIATED CONTINUOUS INK JET PRINTER | |
| EP0299825A2 (en) | Force-balance pendulum accelerometer | |
| FR2509048A1 (en) | CAPACITIVE PRESSURE TRANSDUCER DEVICE WITH LINEAR CHARACTERISTICS | |
| EP0124465B1 (en) | Charge control device and its application to ink droplets speed control. | |
| FR2506008A1 (en) | VIBRATION SENSOR TRANSDUCER FOR GYROSCOPES WITH LASER RINGS | |
| FR2743631A1 (en) | EXTERIOR PRESSURE OR FORCE SENSOR | |
| EP0172766A1 (en) | Apparatus and process for dynamically measuring, at a rotating machine, the play between the rotor and stator faces of said machine | |
| EP0161993A1 (en) | Process and device to annul the electrostatic potential of a helicopter in relation to the earth | |
| EP0136238B1 (en) | Device for measuring the proximity of a metallic conductive surface | |
| EP3889832A1 (en) | Thermal pattern sensor | |
| FR2584207A1 (en) | CONTROL CIRCUIT FOR A PIEZOELECTRIC ADJUSTING MEMBER | |
| FR2485224A1 (en) | BAND POSITION SENSOR AND POSITION MEASURING DEVICE INCLUDING SENSOR | |
| FR2545041A1 (en) | Device for monitoring the charge of drops and ink-jet printing head equipped with it. | |
| FR3060449A1 (en) | METHOD AND DEVICE FOR DETECTING THE SPEED OF JETS | |
| WO2023217643A1 (en) | High-intensity current sensor, in particular for an electric or hybrid motor vehicle | |
| FR2741147A1 (en) | METHOD AND DEVICE FOR MEASURING AN AXIAL DIFFERENCE IN A TENSILE WIRELESS ALIGNMENT SYSTEM | |
| EP0317440A1 (en) | Device for controling a soldering joint by electronic mesurement of the soldering joint area | |
| FR2720510A1 (en) | Charge-compensating capacitive force sensor with interface circuit | |
| FR2557303A1 (en) | Accelerometer with eddy current sensor |
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 |
|
| AK | Designated contracting states |
Designated state(s): DE FR GB IT SE |
|
| 17P | Request for examination filed |
Effective date: 19850507 |
|
| 17Q | First examination report despatched |
Effective date: 19860423 |
|
| 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 SE |
|
| ITF | It: translation for a ep patent filed | ||
| GBT | Gb: translation of ep patent filed (gb section 77(6)(a)/1977) | ||
| REF | Corresponds to: |
Ref document number: 3474792 Country of ref document: DE Date of ref document: 19881201 |
|
| 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: SE Payment date: 19930322 Year of fee payment: 10 Ref country code: GB Payment date: 19930322 Year of fee payment: 10 Ref country code: DE Payment date: 19930322 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: 19930325 Year of fee payment: 10 |
|
| ITTA | It: last paid annual fee | ||
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Effective date: 19940425 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Effective date: 19940426 |
|
| GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 19940425 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Effective date: 19941229 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Effective date: 19950103 |
|
| EUG | Se: european patent has lapsed |
Ref document number: 84460003.1 Effective date: 19941110 |
|
| REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |