DE102013110769A1 - Arrangement for supplying a print head unit having at least one print head with ink in an ink printing device - Google Patents

Abstract

The arrangement for supplying a print head unit with ink in an ink printing apparatus has a back pressure tank that supplies ink to the print head unit. The back pressure tank may be connected to an outlet of an ink reservoir via an ink degassing unit. In addition, the outlet of the reservoir can be connected via the degassing unit with an input of the reservoir. The switching between the two cases can be carried out using two multiway valves, of which a first multiway valve in a first position connects the degassing unit to the outlet of the reservoir and a second multiway valve in a first position connects the degassing unit to an inlet of the reservoir and in a second position establishes a connection of the degassing unit with the backpressure tank.

Description

For single- or multi-color printing of a printing material, for example, a single sheet or a tape-shaped recording medium made of various materials, such as paper, ink printing devices can be used. The structure of such ink printing devices is known, see, for example EP 0 788 882 B1 , For example, ink jet printing devices operating on a drop-on-demand (DoD) principle include a printhead assembly with a printhead or multiple printheads that provide inking units and activators with nozzle units, the activators being controlled by a printer controller to control ink drops toward the record carrier which are directed to the record carrier to apply there printing dots for a printed image. The activators can generate ink droplets thermally (bubble jet) or piezoelectrically.

The structure of a printhead, which has, for example, nozzle units with piezoelectric activators is off US Pat. No. 7,281,778 B2 known. Each nozzle unit includes an ink channel terminating in a nozzle disposed in a nozzle plate and provides an activator disposed on the ink channel. At the nozzle plate of the recording medium is passed. When printing is to be performed, the activators for printing are driven by a printer controller, which then exposes the ink in the ink channels to pressure waves causing the ejection of ink droplets from the nozzles toward the record carrier.

The print heads of the print head unit must be constantly supplied with ink during printing, which should be conveniently degassed. For this purpose, the printing unit can provide a supply arrangement, for example after US 2012/0140003 A1 can be constructed. The printing unit provides here several pressure heads having pressure bar, which are each connected to a distribution tank. The distribution tanks are in turn connected to a back pressure tank in which ink is arranged under pressure so that ink can be transported into the distribution tanks. The back pressure tank is further connected to a reservoir for ink via a pump and a filter. Ink is pumped from the reservoir into the back pressure tank when the ink level in the back pressure tank has dropped below a set level. For this purpose, the ink level in the back-pressure tank can be measured. The ink in the reservoir can be supplemented by means of a pump from an ink bottle. The ink in the back pressure tank can be degassed. For this purpose, a degassing unit is provided which has a known degassing agent and a pump. With the help of the pump ink from the back pressure tank via the degassing agent is pumped back into the back pressure tank and thereby degassed. This degassing process is carried out until the ink has been degassed in the back-pressure tank to a predetermined value.

Out EP 1 938 994 B1 For example, another ink supply system is known in an inkjet printing apparatus. Here, a back-up ink tank is provided which is connected in the printing unit to the printheads to supply the printheads with ink. To complement the ink in the back pressure tank this is connected via a pump with a reservoir for ink. The ink in the counter-pressure potion can be degassed. For this purpose, a degassing unit of a degassing agent, a filter and a pump is provided. Ink from the backpressure tank is returned to the backpressure tank via the degassing unit and degassed. The ink not consumed in the printing unit is fed into a subtank and returned from there via the degassing unit into the back-pressure tank.

The problem to be solved by the invention is to provide an arrangement for supplying an ink printing unit with ink, in which the ink supplied to the printing unit is reliably degassed.

This problem is solved by an arrangement according to the features of claim 1.

The arrangement for supplying a print head unit with at least one print head with ink in an ink printing apparatus has a back pressure tank that supplies the print head unit with ink, and also has a reservoir for ink. An outlet of the reservoir can be connected via a degassing unit with an input of the reservoir (first embodiment of the degassing unit). The back pressure tank can also be connected to the reservoir via the ink degassing unit (second embodiment of the degassing unit). The switching between the applications can be done using two multi-way valves, of which a first multi-way valve in a first position connects the degassing unit with an outlet of the reservoir and a second multi-way valve in a first position connecting the degassing unit with an input of the reservoir and in a second position establishes a connection of the degassing unit with the back pressure tank.

Further developments of the invention will become apparent from the dependent claims.

To degas the ink in the reservoir, the first multiway valve and the second multiway valve can be switched in its first position.

For degassing the transported ink in the back pressure tank, the first multiway valve in its first position and the second multiway valve can be switched in its second position.

• – Die Tinte im Vorratsbehälter kann entgast werden.
• – Die Entgasung des Vorratsbehälters ist im Druckbetrieb und in Pausenzeiten möglich. Damit ist die Zeitnutzung zur Entgasung der Tinte optimiert.
• – Es ist ein größerer Vorrat an entgaster Tinte vorhanden im Vergleich zu Versorgungsanordnungen, bei denen nur der Gegendrucktank entgast wird.
• – Bei hoher Druckauslastung ist ein ausreichend guter Entgasungsgrad sicher gestellt.
• – 100% der Tinte durchlaufen die Entgasungseinheit.

Advantages of the invention are:

• - The ink in the reservoir can be degassed.
• - The degassing of the reservoir is possible during printing and during breaks. This optimizes the time usage for degassing the ink.
• - There is a larger supply of degassed ink compared to supply arrangements where only the back pressure tank is degassed.
• - At high pressure utilization, a sufficiently good degree of degassing is ensured.
• - 100% of the ink passes through the degassing unit.

With reference to exemplary embodiments, which are illustrated in schematic figures, the invention will be further explained.

Show it:

1 a schematic representation of a supply arrangement for ink in a printing unit of an ink printing apparatus, in which an ink reservoir is degassed;

2 a schematic representation of a supply arrangement for ink in a printing unit in which the ink is degassed while it is conveyed into the back pressure tank.

As an example of an inkjet printing device will open US 2012/0140003 A1 referred to, US 2012/0140003 A1 is hereby incorporated into the disclosure. In the following, the arrangement for supplying the printing unit with ink is illustrated by the ink printing device and its function explained.

• – ein Vorratsbehälter 1 für Tinte;
• – eine Tintenflasche 6, die mit dem Vorratsbehälter 1 verbunden ist, um den Tintenverbrauch im Vorratsbehälter 1 zu ergänzen;
• – ein Gegendrucktank 7, durch den die Druckköpfe der Druckkopfeinheit DK mit Tinte versorgt werden;
• – eine Entgasungseinheit GE aus einem Entgasungsmittel 5, einem Tintenfilter 4 und einer Pumpe 3;
• – ein erstes Mehrwegventil 2.1, das zwischen einem Ausgang des Vorratsbehälters 1 und der Entgasungseinheit GE angeordnet ist; das Mehrwegeventil 2.1 kann weiterhin mit einem Ausgang der Druckkopfeinheit DK verbindbar sein;, um die von der Druckkopfeinheit DK nicht verbrauchte Tinte wieder dem Gegendrucktank 7 zuführen zu können; in den Figuren ist diese Verbindung zum Druckkopf DK durch einen Pfeil angedeutet;
• – ein zweites Mehrwegventil 2.2, das zwischen der Entgasungseinheit GE und einem Eingang des Vorratsbehälters 1 sowie einem Eingang des Gegendrucktanks 7 angeordnet ist.

Is shown in 1 an arrangement VA for supplying print heads of a print head unit DK of a printing unit DE with ink. Is provided

• - a reservoir 1 for ink;
• - an ink bottle 6 that with the reservoir 1 connected to the ink consumption in the reservoir 1 to complete;
• - a back pressure tank 7 by which the print heads of the print head unit DK are supplied with ink;
• - A degassing GE from a degassing agent 5 , an ink filter 4 and a pump 3 ;
• - A first multiway valve 2.1 that is between an outlet of the reservoir 1 and the degassing unit GE is arranged; the multi-way valve 2.1 may further be connectable to an output of the print head unit DK; to return the ink not consumed by the print head unit DK to the back pressure tank 7 to be able to supply; in the figures, this connection to the print head DK is indicated by an arrow;
• - A second multiway valve 2.2 located between the degassing unit GE and an inlet of the reservoir 1 and an input of the backpressure tank 7 is arranged.

• a) Entgasung des Vorratsbehälters 1 (erstes Ausführungsbeispiel; 1): Zur Entgasung des Vorratsbehälters 1 wird das erste Mehrwegeventil 2.1 so eingestellt, dass der Ausgang des Vorratsbehälters 1 mit der Entgasungseinheit GE verbunden ist; weiterhin wird das zweite Mehrwegeventil 2.2 so geschaltet, dass der Ausgang der Entgasungseinheit GE mit einem Eingang des Vorratsbehälters 1 verbunden ist. Dann kann mit Hilfe der Pumpe 3 Tinte aus dem Vorratsbehälter 1 über das Filter 4 und das Entgasungsmittel 5 geleitet werden und von dort wieder in den Vorratsbehälter 1 zurückgeleitet werden. Z.B. immer wenn frische Tinte aus der Tintenflasche 6 in den Vorratsbehälter 1 transportiert worden ist, kann die Entgasung der Tinte im Vorratsbehälter 1 durchgeführt werden. Die Tinte im Gegendrucktank 7 wird dabei nicht beeinflusst. Der Entgasungszyklus kann so lange laufen bis ein gewünschter Entgasungsgrad der Tinte im Vorratsbehälter 1 erreicht worden ist. Der Entgasungszyklus kann auch während des Druckbetriebs durchgeführt werden.
• b) Entgasung der Tinte während deren Förderung in den Gegendrucktank 7 (zweites Ausführungsbeispiel; 2).

The degassing unit GE with a degassing agent 5 , a pump 3 and a filter 4 is of known construction; it will be on this US 2012/0140003 A1 referenced, there is also explained their function. About the setting of the multi-way valves 2.1 . 2.2 can either the ink in the reservoir 1 degassed (first embodiment of the degassing unit GE) or the ink on the way to the back pressure tank 7 be degassed (second embodiment of the degassing unit GE). The multi-way valves 2.1 . 2.2 can be realized as 3/2 way valves, for example, with the help of a line for ink on two different supply lines can be switched.

• a) degassing of the reservoir 1 (first embodiment; 1 ): For degassing the storage tank 1 becomes the first multiway valve 2.1 adjusted so that the outlet of the reservoir 1 connected to the degassing unit GE; Furthermore, the second multi-way valve 2.2 switched so that the output of the degassing unit GE with an input of the reservoir 1 connected is. Then, with the help of the pump 3 Ink from the reservoir 1 over the filter 4 and the degassing agent 5 be directed and from there back into the reservoir 1 be returned. For example, whenever fresh ink from the ink bottle 6 in the reservoir 1 has been transported, the degassing of the ink in the reservoir 1 be performed. The ink in the back pressure tank 7 will not be affected. The degassing cycle can continue until a desired degassing of the ink in the reservoir 1 has been achieved. The degassing cycle can also be performed during the printing operation.
• b) degassing of the ink during its delivery into the back pressure tank 7 (second embodiment; 2 ).

Here is the position of the first multi-way valve 2.1 not compared to the first application changed while the second multiway valve 2.2 the outlet of the degassing unit GE on the back pressure tank 7 on. When pumping the ink from the reservoir 1 in the back pressure tank 7 The ink is passed through the degassing GE and thereby degassed. Thus, the back pressure tank 7 Degassed ink from the reservoir 1 fed.

The setting of the multiway valves 2.1 and 2.2 is in 1 and 2 shown; the conveying path of the ink is reinforced in the 1 and 2 drawn.

The individual components of the supply arrangement VA are of known construction, for example US Pat. No. 7,281,778 B2 directed.

LIST OF REFERENCE NUMBERS

DE

printing unit

GE

degassing

DK

Printhead assembly

VA

supply arrangement

1

reservoir

2

Multi-way valve

3

pump

4

filter

5

degassing

6

ink bottle

7

Back-pressure tank

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0788882 B1 [0001]
• US 7281778 B2 [0002, 0021]
• US 2012/0140003 A1 [0003, 0016, 0016, 0018]
• EP 1938994 B1 [0004]

Claims (5)

Arrangement for supplying a printhead unit having at least one printhead with ink in an inkjet printing apparatus, in which an ink-counterstay (FIG. 7 ) is provided, which is connected via a supply line with the print head unit (DK), in which a storage container ( 1 ) is provided for ink, in which a degassing unit (GE) is provided for ink, - at the input of a first multi-way valve ( 2.1 ) is arranged, which in a first position, a connection of the degassing unit (GE) with an outlet of the reservoir ( 1 ) - at whose output a second multi-way valve ( 2.2 ) is arranged, which in a first position, a connection of the degassing unit (GE) with an input of the storage container ( 1 ) and in a second position, a connection of the degassing unit (GE) with the back pressure tank ( 7 ). Arrangement according to Claim 1, in which the degassing unit (GE) has a pump ( 3 ) and a degassing agent ( 5 ) for ink. Arrangement according to Claim 2, in which the degassing unit (GE) additionally has a filter ( 4 ) for ink. Arrangement according to one of the preceding claims, in which for the degassing of the ink in the reservoir ( 1 ) the first multiway valve ( 2.1 ) and the second multi-way valve ( 2.2 ) are switched in their first position. Arrangement according to one of claims 1 to 3, in which the degassing into the counter-pressure tank ( 7 ) ink transported the first multiway valve ( 2.1 ) in its first position and the second multiway valve ( 2.2 ) are switched in its second position.

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