Ink-jet printer for printing on cards

An ink-jet printer for printing on cards includes a printing station having an ink-jet printhead. A reservoir containing an ink is coupled to the ink-jet printhead. The ink includes: a medium consisting of a low-boiling organic solvent, an auxiliary solvent consisting of a high-boiling organic solvent, and a coloring component soluble in said medium. A driving system is adapted to drive the printhead between a first operative condition wherein the ink ejected by the printhead impinges on the card, and at least a second operative condition, wherein the ink ejected by the printhead does not impinge on the card. A control unit is active on the printhead for commanding ejections thereof, and on the driving system for controlling movement of the printhead. The control unit is configured for commanding an ink ejection in the second operative condition before ink ejection in the first operative condition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage Application of PCT/IB2011/055983, filed Dec. 28, 2011, claiming priority to Application No. MI2010A002479 filed Dec. 30, 2010.

BACKGROUND OF THE INVENTION

The present invention refers to an ink-jet printer for printing on cards.

In particular, the invention can be used for printing on cards comprising a plastic material such as, for example, credit cards, smart cards, magnetic cards, etc.

As known, these cards usually bear signs, images, trademarks, that help the users to identify the purpose of the card and to distinguish each card from the others.

In order to print on such cards, the Applicant has found that particular inks can be employed, that comprise: a medium consisting of a low-boiling organic solvent, an auxiliary solvent consisting of a high-boiling organic solvent, and a colouring component soluble in said medium.

These kind of inks evaporate extremely quickly. Therefore, after a very short time after an ink ejection, portions of dried ink can be detected on the nozzle plate, and in particular in the nozzles.

The ink droplets subsequently ejected by the same nozzles hit these portions of dried ink and change their direction accordingly. This causes problems in term of printing quality, since the ink droplets do not land on the expected spot of the card to be printed, and the results of the printing operation is consequently different from the desired one.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an ink-jet printer for printing on cards that is capable of obtaining high quality printing results when using inks that evaporate quickly.

It is another object of the present invention to provide an ink-jet printer for printing on cards that is capable of obtaining printing results that are close to those expected.

These and other objects are achieved by an ink-jet printer for printing on cards according to the claims appended hereto.

Further features and advantages will be apparent from the description of a non-exclusive and preferred embodiment of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENT

In the attached drawings, reference numeral1indicates the ink-jet printer according to the present invention.

The printer1is suitable for ink-jet printing on cards like credit cards, smart cards, magnetic cards, etc.

The printer1(FIG. 1) preferably comprises a storage zone10wherein one or more cards are stored.

Preferably the cards comprise a thermoplastic material.

The laminate polyvinylchloride is formed by a central layer of polyvinylchloride filled with mineral fillers, and a couple of transparent polyvinylchloride films applied each on a respective surface of the central layer.

Preferably the cards have a substantially plate-like shape, having a substantially rectangular shape in a plant view; the rectangular shape has a larger side and a smaller side.

Preferably the larger side has a length comprised between 80 mm and 90 mm, and in particular substantially equal to 85.7 mm.

Preferably the smaller side has a length comprised between 50 mm and 60 mm, and in particular substantially equal to 54 mm.

Preferably the plate-like shape has a thickness comprised between 0.4 mm and 0.8 mm, and in particular between 0.5 mm and 0.76 mm.

Preferably the dimensions of the card are compliance with the ISO 7810 Standard and/or the CR80 Standard.

Preferably the printer1comprises an extraction station20or picking station adapted to extract a card11from the storage zone10.

The extraction station20picks one card at a time from the storage zone10and places it on a support carriage40.

Upon proper command of a control unit, that manages working of the printer1, the carriage40moves from its starting position, close to the extraction station20, to a printing position, at a printing station50.

The printing station50(FIGS. 2 to 5) comprises at least one ink-jet printhead51for ink-jet printing on said card11.

The printhead51is coupled to at least a reservoir52containing ink. Said ink comprises:a medium, or vehicle, consisting of a low-boiling organic solvent;an auxiliary solvent consisting of a high-boiling organic solvent;a colouring component soluble in said medium.

Preferably the vehicle has a boiling temperature lower than 120° C. and in particular lower than 80° C.

Preferably the vehicle is selected in the group of alcohols.

For example, the vehicle can be ethanol, n-propanol, n-butanol.

The vehicle has the tasks of dissolving the various components of the ink and sustaining the formation of the ink bubbles.

Preferably the auxiliary solvent has a boiling temperature higher than 120° C. and in particular higher than 150° C.

Preferably the auxiliary solvent is able to dissolve or to swell the plastic materials, and in particular the thermoplastic material of the cards.

Preferably the auxiliary solvent is soluble in the vehicle.

Preferably the colouring component is soluble in the vehicle.

In this context and in the following claims, the term “soluble” indicates solubility in the vehicle of at least 10% w/w.

Preferably, the colouring components belongs to the so called Solvent family according to the Colour Index terminology.

Preferably the colouring component is a substance that is capable of dissolving in the plastic material of which the cards are made, so as to become integral with the cards and to obtain an optimal printing.

For example, the colouring component can be selected in the group comprising: solvent black 29, solvent black 27; solvent blue 67, solvent blue 44, solvent blue 70; solvent yellow 82, solvent yellow 88; solvent red 125, solvent red 122.

Preferably, the ink also comprises one or more additives such as, for example, levelling agents, in order to improve the uniformity of the distribution of the ink on the cards.

For example, such additives can include silicon derivatives.

In the preferred embodiment schematically shown inFIG. 2, the printhead51is coupled to two reservoirs52.

The printing station50comprises a driving system54(FIG. 5) adapted to drive said printhead51between a first operative condition OC1wherein the ink ejected by the printhead51impinges on the card11, and at least a second operative condition OC2wherein the ink ejected by the printhead51does not impinge on the card11(FIG. 4).

Preferably the driving system54comprises an electric motor54a, and a kinematic linkage54bthat connects the motor54awith the printhead51.

Preferably the driving system54is active on the printhead51for moving the same along a path X.

Preferably the first and second operative conditions OC1, OC2are defined on said path X.

Preferably the printing station50further comprises a support plate53for the printhead51.

As schematically shown inFIG. 1, the support plate53is oriented according to a direction transverse to the path P of the carriage40. In practice, the carriage40moves along the direction indicated by arrow P; the support plate53is transverse, and preferably perpendicular, to such direction.

It is to be noted that, during the printing operation, the carriage40is not located in the position shown inFIG. 1: such position is that in which the carriage40receives the card11from the extraction station20.

When the printing step has to be performed, the carriage40(on which the card11is positioned) moves to a different position, substantially below the support plate53, so that the card11is in the position schematically shown inFIGS. 2 and 4.

The support plate is mounted to a frame2of the printer1.

Preferably, the printhead51is slidably mounted on the support plate53.

The driving system54is adapted to move the printhead51back and forth along the support plate53during the printing operation, while ejecting ink onto the card11.

Preferably the path X is defined on said support plate53.

The printing station50further comprises a control unit55active on the printhead51for commanding ink ejections thereof.

Preferably the control unit55is provided with a memory (not shown), in which data/images to be printed are stored, and with an operative module, that generates proper command signals for the printhead51in order to print the stored data.

The control unit55is also active on said driving system54for controlling movement of said printhead51.

In particular, the control unit55is configured for commanding an ink ejection of the printhead51in the second operative condition OC2before ink ejection in the first operative condition OC1. Preferably, ink ejection of the printhead51in the second operative condition OC2occurs before every ink ejection swath in the first operative condition OC1.

In more detail, every time the printhead51has to eject ink onto the card11in a swath, or carriage pass, so as to print something on it, the control unit55acts on the same printhead51commanding a previous ink ejection in the second operative condition OC2. Possible debris or portions of dried ink accumulated in the nozzles of the printhead51are removed before the actual printing step is performed, so that the ink ejected for printing follows the desired direction and the printing results is actually the one expected.

Preferably, in the first operative condition OC1the printhead51faces the card11. In particular, the nozzle plate of the printhead51faces the card11, so that the ink ejected through said nozzles lands onto the card.

Preferably, in the second operative condition OC2the printhead does not face the card11.

Preferably, the first operative condition OC1comprises one or more first positions P1(FIG. 4) of the printhead51on the path X. In particular, the first position(s) is(are) defined on the support plate53.

In the first positions P1, the printhead51(in particular, the nozzles thereof) face the card11. The first operative condition OC1may comprise a plurality of first positions P1since, during a single printing operation, the printhead51can be moved, e.g. in a swath, with respect to the card11, so that more than one ejections occur, in respective different first positions P1, before the printhead51is driven to the second operative condition OC2.

Preferably, the second operative condition OC2comprises at least a second position P2(FIG. 4) of the printhead51on the path X. In particular, the second position P2is defined on the support plate53.

In the second position P2the printhead51, and in particular the nozzles thereof, does not face the card11. Therefore, the ink ejected in the second position P2does not impinge onto the card11.

Preferably, the printing station50comprises at least a first discharge receptacle56in which the printhead51ejects ink in the second operative condition OC2.

Preferably, the second operative condition OC2further comprises a third position P3(FIG. 4) of the printhead51on the path X. In particular, the third position P3is defined on the support plate53.

Preferably, the first position(s) P1is/are interposed between the second position P2and the third position P3. In other terms, the second and third positions P2, P3are at opposite sides with respect to the first positions P1.

Preferably, the printing station50further comprises a second discharge receptacle57, wherein the printhead51ejects ink when it is in the third position P3.

Preferably the path X has a first end X1and a second end X2.

In a preferred embodiment, the second position (P2) is defined at the first end X1of the path X.

Thus, as schematically shown inFIG. 4, along the path X are orderly defined (in the figure, from the leftmost end to the rightmost end):the second position P2, defined at the first end of the path X;the first position(s) P1;the third position P3;a rest position RP, at the second end X2of the path X; the rest position RP is the position at which the printhead51is located when is it not is use.

Preferably, the first discharge receptacle56is positioned at the second position P2of the printhead51.

In particular, the first discharge receptacle56is positioned at the first end X1of the path X.

In use, the control unit55acts on the printhead51and on the driving system54in order to perform the following steps:the printhead51is moved in the second position P2, a predetermined amount of ink is ejected in the first discharge receptacle56, so as to clear the nozzles;the printhead51is then moved to the first position (s) P1, and ink is ejected onto the card11, typically in a swath;the printhead51is then moved to the third position P3, wherein a predetermined amount of ink is discharged into the second discharge receptacle57;the printhead51is then moved to the first position (s) P1, for another ejection onto the card11, typically in a further swath in a direction opposite to that of the previous swath.

The above steps can be repeated a number of times, until printing of the card is finished.

The invention can achieve important advantages.

The printer according to the invention is capable of obtaining high quality printing results even using inks that evaporate quickly.

Another advantage consists in that the printer according to the invention is capable of obtaining printing results that are extremely close to those expected.

In the printer of present invention the printhead51in the first operative condition OC1faces the card11to be printed.

The printhead51in the second operative condition OC2does not face the card11to be printed.

Said second operative condition OC2further comprises a third position P3on said path X.

In the printer of present invention the one or more first positions P1are interposed between the second and the third positions P2, P3on said path X.

Said card11has a substantially plate-like shape, having a substantially rectangular shape in a plant view, said rectangular shape having a larger side and a smaller side.

Said larger side has a length comprised between 80 mm and 90 mm.

Said smaller side has a length comprised between 50 mm and 60 mm.

In the printer of present invention the plate-like shape has a thickness comprised between 0.4 mm and 0.8 mm.

In the printer of present invention the step of driving said printhead51between said first and second operative conditions OC1, OC2comprises moving said printhead51along a path X on which said first and second operative conditions OC1, OC2are defined.

Ink ejection in said first operative condition OC1occurs during swaths of the printhead along said path X, wherein ejection of the printhead in the second operative condition OC2occurs before every ink ejection swath in the first operative condition.

Said first operative condition OC1comprises one or more first positions P1on said path X, and said second operative condition OC2comprises at least a second position P2on said path X.

The printhead51in the first operative condition OC1faces the card11to be printed.

The printhead51in the second operative condition OC2does not face the card11to be printed.

Said second operative condition OC2further comprises a third position P3on said path X.

Said first positions P1are interposed between the second and the third positions P2, P3on said path X.

In one embodiment of a method according to at least a first discharge receptacle (56) is provided in which said printhead (51) ejects ink in the second operative condition (OC2).

In the printer of present invention is comprised a second discharge receptacle57, said printhead51facing said first discharge receptacle56in the second position P2, said printhead51facing said second discharge receptacle57in the third position P3.

In the printer of present invention is comprised a support plate53on which said printhead51is slidably mounted, said path X being defined along said support plate53.