EP0904945A2 - Device for conveying of printing supports and for printing on them - Google Patents

Abstract

The device for transporting and printing on print media has an inclined guide plate (2) and a means of transport (1) orthogonal to this guide plate (2) and an auxiliary device. An inkjet print head (4) controlled by a controller (40) is fixedly arranged in a recess (21) in the guide plate (2) during printing. The recess (21) is designed such that the print carrier (3) is exposed downstream with the printed area. According to the invention, the pressure carrier (3) transported by the transport means (1) bears without jamming against an auxiliary device which has an increasing guide and allows a defined slip perpendicular to the surface of the transport means. Regardless of the inclination of the machine's footprint, non-contact printing is carried out with the ink print head (4) with high print quality for print carriers (3) transported upright or lying down. A support device (30) is placed in front of the guide plate (2) to adapt the angle of inclination α. <IMAGE>

Description

The invention relates to a device for transport and Printing on print media, especially letters in franking machines.

In such machines, the print carrier on one The printing device is guided along and in one pass Franking and possibly further information printed.

It is common to see the print carrier lying flat either for example US 5,467,709 or standing on an edge, see for example DE 25 24 670 C2 and US 5,025,386, at To guide the printing device.

In any case, it is important that the print carrier and the printing device come to a defined position in relation to one another so that the print is made at the intended location and with sufficient quality.
In the case of horizontal transport, a relatively large contact area is required in accordance with the largest print carrier format used, which in turn requires a correspondingly large footprint for the machine.
In the solution according to US Pat. No. 5,467,709, printing is carried out without contact by means of an ink print head. The letter is transported clamped between a driven conveyor belt and spring-loaded pressure rollers, the letter also abutting a longitudinal guide plate. The longitudinal guide plate is provided with a recess adapted to the conveyor belt and with a rectangular recess for the ink print head, over the diagonal of which the row of nozzles of the ink print head runs. The conveyor belt, the length guide plate and the ink print head are arranged above the letter. The resilient pressure rollers and a pressure roller resiliently mounted in the printing area are arranged under the letter. The spring travel of the pressure rollers and the pressure plate corresponds to the maximum thickness of the letters, which can vary between 0.2 mm and 20 mm. The spring force must be sufficient for the entire weight range of the letters - approximately 20 to 1000 g - and also for the letters to lie sufficiently flat in the area of the recess for the print head. For the non-contact ink printing process, a constant, as small as possible distance between the print carrier and the ink print head must be maintained, so that on the one hand misaligned splashes have little effect and on the other hand the print carrier does not touch the nozzle surface and thus lubricants are avoided. However, there is still the risk of smearing if the letter leaves the area of the recess and then inevitably slides along the longitudinal guide plate.
In the case of rapidly changing mixed mail, these conditions are difficult to meet.
On the other hand, a system for processing outgoing mail letters of different weights and different dimensions is known, see DE 24 24 670 C2, in which the letters are conveyed upright by means of a transport path. The conveyor track has driven pairs of rollers and a conveyor belt. In the area in front of the franking imprint, the letter is grasped by the conveyor belt in the form of a friction belt and transported via guide rollers to a postage drum or printing roller with counter-pressure roller. The counter-pressure roller is mounted on a movable printing plate, the distance from which is adjustable from the printing roller in accordance with the thickness of the letter just passing through the franking device.
In addition to the fact that pressure rollers will no longer meet the increased requirements in the future, the pressure plate contains a considerable number of components to be moved. This requires a correspondingly large amount of energy to overcome the inertia.
Furthermore, a franking machine is known, compare US 5,025,386 in which the letters are conveyed upright, slightly inclined on a rotating conveyor belt. The letters rest on a guide block in which a print window is provided. In the print window, a thermal print head can be moved vertically and laterally, with which franking is printed on the letter. The size of the print window must be adapted to the maximum length and width of the print image. The individual letter is moved to the print window and then stopped and pressed against the guide plate or the print window by means of a pressure plate. The pressure plate is driven by a motor via gear drives and a crank joint. This is a relatively large mechanical effort and the counterpressure forces to be applied for thermal printing are also large.
After printing, the letter is released and transported on. It is evident that only low letter throughput rates can be achieved with this intermittent operation. The effort for the thermal print head adjustment is considerable.

In German patent DE 196 05 014 C1, a device for printing a print carrier standing on the edge was already created to simplify the transport of letters and to improve the printing technique, which device enables contactless printing by means of an ink print head. Compared to the footprint of the franking and / or addressing machine, a guide plate inclined slightly over 90 ° with a recess for an inkjet print head and orthogonal to the guide plate is proposed a circumferential conveyor belt, on which the print carriers, in particular letter envelopes or other mail pieces (tilted), rest against the guide plate , wherein the guide plate is preferably inclined at 18 ° from the perpendicular. Continuous printing is possible thanks to the use of continuous transport and the ink printhead. Since printing is done without contact, the application force is sufficient for a defined position of the mail piece relative to the print head due to the inclination of the guide plate and the conveyor belt. The friction on the guide plate can be kept low by means of a corresponding smooth surface and / or slide rails. The recess, which is open in the direction of transport, prevents the print image from smearing and extends the drying time for the print dots. In the event that the drying time of the ink is very short, it has been proposed to provide a correspondingly long closed recess.
Now it is due to the too high transport speed or insufficient smudge resistance of the ink if smearing of the printed image occurs when the mail pieces are deposited; in any case, a drying time which limits the transport speed should be as short as possible for the ink droplets applied to the printed pixels. But this is only possible to a limited extent with an appropriately selected ink.
In the case of mail pieces which have an unstable or uneven content, it is difficult to constantly maintain a defined distance from the print carrier surface to the nozzles of the ink jet print head in the region of the recess.
It is also clear that with a strong inclination of the guide plate with respect to the solder on the reference plane between a thin envelope, in particular a franking strip or a similar print carrier and the conveyor belt, a differential speed can arise if the friction of the envelope or print carrier surface on the guide plate and / or the slide rails cannot be kept low enough against the friction of the envelope or pressure carrier edge on the conveyor belt. It is obvious that such a device is more suitable for thick envelopes or parcels or mail pieces with a higher weight than for thin envelopes or light mail pieces. This solution is unsuitable for printing on address or franking strips.

In the German patent DE 196 05 015 C1 was already Improving letter transport a device for printing of a print carrier standing on the edge, which one Non-contact printing by means of an ink print head on thin Print media allowed. As a means of applying a feed force on the print carrier along the guide plate are on the Conveyor belt that can be moved towards and away from the guide plate Pressure elements arranged. That by the applicant on the basis of o.g. After all, the patented franking system jet mail® allows the transport of up to 5500 letters per hour with a thickness up to to 20 mm and is the fastest franking system with ink-jet printing technology. This solution also guarantees the non-slip Transport of franking strips and even processed mixed mail. By the use of pressure elements on the conveyor belt surface, is the latter in contrast to the solution according to DE 196 05 014 C1 cannot be used in full width. Of course, this leads to annoying Delays if the franking system for letters that are too thick is stopped in order to print on and around a franking strip then stick on by hand. Therefore it would be desirable if even thicker letters are automatically transported and franked could.

The pressure elements also protrude so far from the conveyor belt surface out that a position opposite the recess for the ink printhead is reached. For applying franking imprints a first nozzle of the ink print head must already be in the Distance of 10 mm from the contact edge on the conveyor belt surface to press. There is at least one pressure element and at least a number of nozzles for which a clamping of the Postpiece or print carrier, for example a franking strip takes effect. This clamping is with certain thin mail pieces only applicable to a limited extent, for example if the letter is paper clips or contains other bumps in this area or if one unstable envelope contents no form stability of the mail item guaranteed. In in such cases, the distance of the print carrier surface to Noise level of the ink print head can not be kept constant which contributes to the deterioration of print quality.

It is an object of the invention to provide a device for the rapid transport and printing of a print carrier standing on the edge, which allows non-contact printing by means of an ink jet print head for very thin and thick mail items alike and thereby avoids the disadvantages of the prior art.
The print quality of the print printed using inkjet printing technology should also be improved for all types of mail items, regardless of whether they have uneven or unstable content.
Another task is to safely transfer a high speed in the transport direction to the print carrier and to minimize the drying time of the ink after printing.
In one variant, an inclination to the reference plane in any direction should even be permissible for the machine footprint, with the print quality remaining the same.

According to the invention, this object is achieved according to the claims solved.

The device for transporting and printing on print carriers includes an inclined guide plate and a means of transport orthogonal to this guide plate and an auxiliary device. An ink jet print head controlled by a controller in a recess of the guide plate is fixedly arranged during printing.
The recess is designed in such a way that the print carrier is exposed downstream with the printed area, ie does not abut the guide plate.

The print carrier stands with its edge or lies with it Side surface on the means of transport so that its to be printed Surface rests on a guide. The device for printing such a standing or lying print carrier has one vertical guide plate or an inclined to the vertical Guide plate, the inclination positive or negative compared to the Can be vertical to the reference plane. The reference plane is one level horizontal footprint of the machine, for example a table top. The above Vertical is subsequently also used as a plumb line Designated reference plane.

It has been shown that the best print quality is achieved when the surface to be printed lies flat and regardless of the position in which the print carrier is transported to the reference plane during printing. It is further assumed that a suitable way of applying the pressure carrier to the guide is crucial and that a clamping in the pressure area must be avoided. Thus, an auxiliary device with a guide without clamping is used to tighten the print carrier surface.
This auxiliary device according to a first variant includes a first transport and guide means and is effective under the influence of gravity on a guide plate which is positively inclined with respect to the vertical to the reference plane. The print carrier stands on a means of transport and at the same time lies against the auxiliary device, which has a rising guide and allows a defined slip perpendicular to the surface of the means of transport. The transport means, in cooperation with the transport and guiding means, allows a high speed to be transferred to the print carrier in a slip-free manner in the transport direction.

According to the invention when transporting the print medium by means of the first transport and guidance means provided by an incline of the guide means of the guide plate, which with a Vacuum means of transport is equipped, the distance the parts of the print carrier surface remote from the printing area to the near the contact edge of the print carrier on the Parts of the print carrier surface lying on the surface of the transport medium to enlarge to the desired tightening under the influence of gravity to achieve on the print medium.

Alternatively, one is used to tighten the print carrier surface Auxiliary device used according to a second variant, the Auxiliary device on a vertical guide plate or on a negatively inclined with respect to the vertical to the reference plane Guide plate is arranged to provide a jam-free guide achieve. Such an auxiliary device includes two transport and Leadership means. The advantage over the first variant is in that tightening even with very light print media, especially thin letters, with the same effectiveness possible is like thicker print media or letters.

According to the invention, the tightening of the print carrier surface to be printed through the aforementioned means of transport and guidance Auxiliary device achieved that a negative pressure on both sides Apply the printing area to parts of the print carrier surface wherein at least a first means of transport and guidance on remote parts of the print carrier surface facing the printing area exerts a vacuum and with one in the direction of transport rising guide is equipped as well as being another Means of transport and guidance a negative pressure on parts of the Print carrier surface near the contact edge of the print carrier on the Transport surface and parallel to the transport direction of the Exercises means of transport.

Another advantage of the auxiliary device according to the invention second variant is that the footprint of the machine is not must be level. The means of transport and management secure a system to the guide plate or its slide rails also under difficult conditions. The stand area must be opposite the first Variants are therefore not inclined to the reference surface, but here an inclination is even allowed when setting up.

Further explanations can be found in the subclaims.

Fig. 1a,

perspektivische Ansicht einer erfindungsgemäßen Vorrichtung nach der ersten Variante, mit einer Hilfsvorrichtung an einer gegenüber der Vertikalen zur Bezugsebene positiv geneigten Führungsplatte mit einer Führung ohne Klemmung.

Fig. 1b,

perspektivische Ansicht einer erfindungsgemäßen Vorrichtung nach der zweiten Variante, mit einer Hilfsvorrichtung an einer gegenüber der Vertikalen zur Bezugsebene negativ geneigten Führungsplatte mit einer Führung ohne Klemmung.

Fig. 2a bzw. 2b,

Ansicht der erfindungsgemäßen Hilfsvorrichtung an der Führungsplatte nach der ersten bzw. zweiten Variante,

Fig. 3a,

Schnitt entlang der Linie l-l' durch eine Hilfsvorrichtung an der Führungsplatte, gemäß der ersten Variante,

Fig. 3b,

Schnitt entlang der Linie A-A' durch eine Hilfsvorrichtung an der Führungsplatte, gemäß der zweiten Variante,

Fig. 4a, 4b,

Schematische Luftführungsanordnung der Hilfsvorrichtung bei der Führungsplatte und deren Steuerung, nach der ersten bzw. zweiten Variante,

Fig. 5,

Variante für waagerechten Druckträgertransport.

The invention is explained in more detail below using the exemplary embodiment. Show it:

Fig. 1a,

Perspective view of a device according to the invention according to the first variant, with an auxiliary device on a guide plate positively inclined with respect to the vertical to the reference plane with a guide without clamping.

1b,

Perspective view of an inventive device according to the second variant, with an auxiliary device on a guide plate negatively inclined with respect to the vertical to the reference plane with a guide without clamping.

2a or 2b,

View of the auxiliary device according to the invention on the guide plate according to the first or second variant,

3a,

Section along the line ll 'through an auxiliary device on the guide plate, according to the first variant,

3b,

Section along the line AA 'through an auxiliary device on the guide plate, according to the second variant,

4a, 4b,

Schematic air duct arrangement of the auxiliary device in the guide plate and its control, according to the first or second variant,

Fig. 5,

Variant for horizontal print carrier transport.

To simplify the presentation and for better understanding is the drawing is partially schematic.

1a shows a perspective view of a device according to the invention according to the first variant, with an auxiliary device on a guide plate which is positively inclined with respect to the vertical to the reference plane and which has a clamp-free guide. A first means of transport 1 consists of a conveyor belt 10 and two rollers 11, 11 '. One of the rollers is the drive roller 11 '.
Both rollers 11, 11 'are preferably designed as toothed rollers in a manner not shown, correspondingly also the conveyor belt 10 as toothed belt. This ensures clear power transmissions.
The drive roller 11 is seated with an incremental encoder 5 on a common axis and ensures an accurate detection of the transport path. The incremental encoder 5 is designed, for example, as a slotted disk which interacts with a reflex light barrier 6 (light-emitting diode / photocell). This has already been explained in DE 196 05 014 C1.

The coordinates of an imaginary coordinate cross point with x in Direction of transport and designate the longitudinal edge of the conveyor belt. They point with z in the width direction of the conveyor belt 10 and with y in the orthogonal direction to it, i.e. towards the Expansion of the guide plate 2. The conveyor belt 10 is in the xz plane at an angle α to the reference plane. The guide plate 2 is in the xy plane and forms an angle with the conveyor belt 10 of 90 °.

In the case of a positive inclination, the inclination of the guide plate is over 90 ° to the reference plane and the pressure carrier 3 already has a secure contact position due to the force of gravity on guide means 231 of the guide plate 2, as is already shown in DE 196 05 014 C1. The transfer of the transport speed to the print carrier 3 takes place in addition to the first transport means 1, now according to the first variant also through the special design of the auxiliary device 20 according to the invention as a transport and guiding means of the guide plate 2 which generates a negative pressure <18 ° of the zx plane from the plumb line.
Due to the smaller angle α, a lower friction between guide means 23 of the guide plate 2 and the pressure carrier 3 is already achieved. The means of transport 1 is preferably only a conveyor belt 10. Alternatively, an arrangement of a plurality of rollers or the like can also be used.
The guide means 23 of the guide plate 2 are preferably slide rails 231. The print carrier 3 is, for example, a letter which is to be franked. In order to achieve high print carrier quantities, the most important thing is a high cycle speed and printing in a single pass.

A guide plate 2 is orthogonal to the conveyor belt 10, for example arranged positively inclined at an angle α = 10 ° to the perpendicular. The Letters 3 standing on the conveyor belt 10 lie on the guide plate 2 with their surface to be printed 300. When moving of the conveyor belt 10, the letters 3 slide on the fixed Guide plate 2 along. To improve the sliding properties the guide plate 2 with slide rails 231 parallel to the transport direction Mistake. In the downstream part, the guide plate 2 at least one recess 21. The recess 21 is in height of the franking imprint to be applied. An inkjet printhead 4 is parallel in the recess 21 with its nozzle surface to the guide plate 2 arranged so that the distance to the past Letter is approximately 1 to 2 mm. Still further downstream are agents that accelerate ink drying, for example one Motor suction pump 12 with fan 121, arranged. The letter will be there blow air at the level of the printed area and preferably guided by means of slide rails 231 without contact.

A sensor 7 is in the guide plate 2 shortly before the recess 21 provided for the start of letter recognition. In cooperation with the Incremental encoder 5 is the pressure signal by the sensor 7 triggered. The inkjet print head 4 is controlled by a controller 40 controlled and is with an ink reservoir via a Ink delivery system connected (not shown).

During printing, the one in the recess remains Inkjet printhead 4 a fixed position from which the Inkjet printhead 4 in the printing breaks or after completion of all Printing in one position to a - not shown - Cleaning and sealing station (RDS) can be pivoted, what in the unpublished German application entitled: "Arrangement for positioning an ink jet print head and a Cleaning and sealing device "is explained in more detail (AZ 3089-DE).

To an imaginary parallel at a distance from the contact edge 31 of the Print carrier 3 on the conveyor belt surface of the first means of transport there is a line l-l 'with the slope h at the end of the Auxiliary device in the direction of transport. The leadership of one Transport and guide means 20 generating negative pressure on this line l-l 'to the distance from the to be printed Area distant parts of the print carrier surface to the near the contact edge 31 of the print carrier 3 on the conveyor belt surface to enlarge lying parts of the print carrier surface 300, to achieve a tightening under the influence of gravity. The Line l-l 'closes with a parallel at a distance from the contact edge 31 an angle β of less than or equal to 20 °.

2a shows a view of the auxiliary device according to the invention on the guide plate 2 for tightening the print carrier surface and for guiding without clamping according to the first variant. The auxiliary device according to the invention is a conveyor belt 201 guided at an angle β by means of guide means 204 to 206.
Holding rails 205, 208 of the auxiliary device rest on the respective contact rail 232, 233 of the guide plate 2 on both sides before and after the recess 21 in the guide plate 2 for inkjet print head 4, ie on both sides of the printing area.

A transport and guiding means 20 of the invention Auxiliary device is orthogonal to guide the print carrier 3 the contact rails 232, 233 by the aforementioned contact rails 232, 233 of the guide plate 2 in position and by fastening Holding rails 205, 208 at a defined distance from the contact edge 31 held. The guide means 204, 206 are attached in front of the Recess 21 on the holding rail 205 at a defined distance. The Attachment of the guide means 204, 206 takes place after the Recess 21 in the guide plate 2 on the holding rail 208 in such a distance that the distance is longer by the path length h is than the distance of the attachment to the holding rail 205 in front of the Recess 21 in the guide plate 2. This results in an increase h when guiding the print carrier 3 in the transport direction along the Line l-l 'between the two holding rails 205 and 208. Zur Applying negative pressure is the means of transport and guidance 201 to 204, 206 connected to an intake duct 17.

The conveyor belt 201 - shown in FIG. 3a - runs over guide rollers 18 and a drive roller 19 of the transport and guide means 20 of the auxiliary device with the same transport speed as the - shown in Fig. 1a - conveyor belt 10 as soon as by means of a sensor 8 a print carrier 3 is detected. Preferably both Drives, i.e. the drive of the means of transport 1 and the drive 25 of the Auxiliary device coupled together. A drive 25 of the drive roller 19 in the auxiliary device works synchronously with the drive of the Drive roller 11 '. For example, one of the drives is a deflection gear trained and draws a power coupling from the other Drive as soon as a print carrier 3 reaches the sensor 8. The drive 25 is connected to a controller 40, which has a corresponding Switching or clutch controls.

A flexible shaft 24 preferably connects the axis 28 of the drive 25 to the axis 29 of the drive roller 19 for the conveyor belt 201. Both axes 28 and 29 are at an angle β to one another. The flexible shaft consists, for example, of a coil spring and a fitting piece of plastic tubing.
Alternatively, the shaft 24 can also be designed as a cardan shaft.

3a shows a section through the auxiliary device along the line l-l 'on the guide plate 2. The intake duct 17 connects one Suction chamber 203 in the suction housing 204 of the transport and Guide means 20 of the auxiliary device with a nozzle 16 a - shown in Fig. 4 a - pressure hose 15, the one predetermined vacuum p applies. The negative pressure p in the intake space 203 of the suction housing 204 is through a perforated plate 206 to the Holes 202 of the conveyor belt 201 passed. The conveyor belt 201 has a predetermined length and has a number only in the region 200 Openings 202 on which the negative pressure on the print carrier surface 300 forward.

The conveyor belt 201 closes all openings in the perforated plate 206 - as shown in Fig. 3a - and thus a negative pressure in the Intake space 203 can be built. As soon as using sensor 8 If pressure carrier 3 is detected, controller 40 increases the negative pressure and causes the conveyor belt 201 to move longitudinally the guide along the line l-l '. The length of the conveyor belt 201 corresponds to the sum of the print carrier length of the shortest Print carrier 3 and the shortest distance between two in succession supplied pressure carrier 3. The drive 25 is controlled by the controller 40 controlled accordingly, so that the conveyor belt 201 after a Circulation is stopped again if no further print medium is detected becomes. This can be achieved by the drive 25 from Drive of the drive roller 11 'is uncoupled and stopped.

The friction pairing between the auxiliary device and the print carrier 3 (paper or similar material) has the highest possible values.
Within the transport and guiding means 20 of the auxiliary device between the perforated plate 206 and the conveyor belt 201, the lowest possible friction values are achieved. The conveyor belt 201 of the transport and guide means 20 of the auxiliary device consists of a lubricious, abrasion-resistant and flexible plastic, which is coated on the outside with rubber. This results, for example, in the friction pairing paper / rubber, a high coefficient of static friction µ.
A suction force F _s , which is proportional to the product of the pressure p and the area A of an opening 202 on the conveyor belt 201, is exerted orthogonally on the surface 300 of the pressure carrier 3 via openings 202 in the conveyor belt 201. The following applies to the area A of the surface 300 on which the pressure p acts: F s = p * A

The force exerted by the auxiliary device over all openings 202 on the pressure carrier 3 is proportional to the suction force F _s and thus the static friction force results from the equation: F H = µ * F s = µ * p * ΣA

4a shows a schematic air guide arrangement in the Guide plate, according to the first variant, with associated control 40. The air flow takes place from the suction space 203 of the transport and Guide means 20 of the auxiliary device via the intake duct 17 Connection 16, the pressure hose 15 to the valve 14, the pressure hose 13 to the motor suction pump 12 with an accelerating the ink drying Medium 121.

The control 40 is at least on the input side with the sensor 8 and on the output side with the controllable valve 14 and the motor suction pump 12 connected. The control 40 starts printing calculated according to the transport speed. With one over an increase in negative pressure exceeding a predetermined negative pressure the valve 14 draws secondary air from the environment. The size of the predetermined vacuum can be controlled by the controller.

If the pressure carrier 3 reaches a first sensor 8, the valve 14 for secondary air is then closed, for example by the valve 40 being set accordingly by the controller 40 in order to achieve a maximum negative pressure. If necessary, the output of a motor of the pump 12 is increased briefly. Subsequently, the suction force F _{s is} gradually reduced with the transport of the pressure medium along the line II 'by the pressure p being reduced by means of the controllable valve 14. The effort required to overcome the static friction force exerted by the transport and guide means 20 becomes less and less in the direction of transport as the transport proceeds, so that there is no lifting of the print carrier, but only the tightening of the surface of the print carrier results.

The controller 40 is connected, for example, in a further embodiment - in the manner shown in FIG. 1a - to the sensors 7, 8 and 9 on the input side. The start of printing is calculated by the controller 40 in accordance with the transport speed, wherein the actual transport of the print carrier 3 can be checked with the inclusion of the sensors 7 and 8.
At the print head at the level of the contact edge 31 of the print carrier 3 on the conveyor belt surface of the first transport means, an additional sensor 9 is arranged, which is queried by the controller 40 in order to report a possible lifting of the print carrier 3 from the conveyor belt surface of the first transport means 1 and then to reduce the suction force F _s accordingly by reducing the negative pressure p by means of the controllable valve 14.

In addition, the controller 40 controls the RDS, not shown and further assemblies of the base station, for example the Inkjet printhead 4, or possibly further stations, not shown of a franking system, such as that in the Pre-published German application 197 11 997.2, entitled: "Arrangement for communication between a base station and further stations of a mail processing machine and to their Emergency shutdown "was described in more detail.

1b shows a perspective view of the device according to the invention according to the second variant, with an auxiliary device on a guide plate which is inclined negatively with respect to the vertical to the reference plane and which is also equipped with a guide without clamping. In addition to the first transport and guide means 20, a further transport and guide means 20 'according to the invention is additionally arranged on both sides of the ink jet print head 4 in such a way that the print carrier surface 300 to be printed is tightened.
Compared to the first variant, the tightening is now achieved even without the action of gravity, so that the tightening is possible with very light pressure carriers 3, in particular thin letters, with the same effectiveness as with thicker pressure carriers 3 or letters.

According to the invention by means of transport and guidance 20, 20 'a negative pressure on both sides of the printing area Parts of the print carrier surface exercised, the first transport and Guide means 20 on remote from the printing area Parts of the print carrier surface 300 exerts a vacuum and with is equipped with a guide that rises in the direction of transport, as well as the further transport and guiding means 20 ' Negative pressure on parts of the print carrier surface near the contact edge of the print carrier on the conveyor belt surface and parallel to Transport direction of the conveyor belt exerts.

If the inclination is negative, the inclination of the guide plate is less than 90 ° to the reference plane and the print carrier 3 has an application position Guide means of the guide plate 2, which upright by means be obtained which exert a negative pressure. According to the invention can the guide plate in the device according to the second variant also exactly 90 ° or a positive inclination to the reference plane take in. In the version with exactly 90 °, the guide plate is in the Lot. This is compared to the version with a positive tendency minimizing the friction between the pressure carrier 3 and the reached other guide means 23, which is not a means of transport to have. The inclined position is preferably at an angle of 0 ° α α <10 ° the zx plane from the plumb line. This positive tendency to the reference plane can already be done by tilting the base of the machine caused without this having a negative impact on the Would have print quality.

A negative inclination hardly results in friction losses or Material wear. Such an inclination also makes it easier Rotate and deposit the mailpieces after printing so that the Imprint after the filing is visible from above. An additional one preceding application device 30 has opposite the guide plate 2 a positive slope, i.e. the inclination of a - in Fig. 1b shown - guide plate 32 is over 90 ° to the reference plane and the pressure carrier 3 here already has a gravity secure position on the guide means of the guide plate 32. The application aid device 30 points to the application guide plate 32 preferably slide rails 33, which have a positive Inclination or vertical to a negative inclination of the guide plate 2 adapt.

A strip dispenser device (not shown), which is also positioned parallel to the application aid 30, applies the strip to the further transport and guiding means, which from the time of application creates a negative pressure on parts of the print carrier surface near the contact edge 31 of the print carrier on the surface of the conveyor belt 10 and parallel to the transport direction of the conveyor belt 201 exercises.
The strip dispenser device is preferably constructed as described in more detail in the unpublished German application 197 12 077.6 with the title: "Arrangement for printing strip-shaped print carriers". If necessary, it can adapt a positive inclination or vertical to a negative inclination, as can the application aid device 30.

The negative pressure-generating transport and guide means of the guide plate 2 with negative inclination hold the pressure carrier 3 transferred by the application aid 30 against the effect of gravity, first avoid a high initial pressure p _a - generated by the suction power of the pump 12 - to prevent the pressure carrier from falling over Conveyor belt 10 and then secure the tightening later in the course of the transport by an increase in the guide with an increasing suction area ΣA on the pressure carrier surface 300 and with a simultaneously decreasing pressure p.
It is provided that the pressure p 'of the second transport and guide means 20' of the auxiliary device near the contact edge 31 is not reduced. Advantageously, overextension or tearing of the surface to be printed is avoided by a push in the vertical direction on the conveyor belt 10. Lifting even thin print media from the contact edge 31 is likewise reliably avoided and an additional sensor 9 can therefore be dispensed with. At the same time, the interaction with the conveyor belt 10 of the transport means 1 guarantees a slip-free transport in the transport direction.

This - shown in Fig. 1b - second variant of device according to the invention also has a guide without Clamping and is equally suitable for one versus the Vertical inclined positively or negatively to the reference plane Guide plate 2. The recessed area in the guide plate 2 has at least one recess 21 for an ink print head 4, whose nozzle plane is arranged parallel to the guide plate 2, the means of the guide plate 2 behind the recess 21 in Transport direction (downstream) is designed such that the print carrier 3 is in contact with this recess 21 and the Drying of the ink pressure points is accelerated.

To help the ink dry quickly, one is Air jet expelling agent is provided. This will make solvent evaporation accelerates and the evaporating solvent the ink drains away quickly. The air jet expelling means is 121 preferably part of the motor suction pump 12. The air jet is directed to the surface 300 of the print carrier. The blow with the Air jet also accelerates the detachment of the print medium from the Guide means and the rotation in the desired storage position.

2b shows a view of the auxiliary device on a guide plate for tightening the print carrier surface and for guiding without Clamping according to the second variant. The print carrier 3 is not yet has been detected by the sensor 8 and the conveyor belts 201, 201 ' Transport and guide means 20, 20 'are not yet effective and remain in the drawn starting position. Here is the one Side of the conveyor belts 201, 201 'without the openings 202, 202' in the Pressure area between the holding rails 205 and 208 and the other Side of the conveyor belts 201, 201 'with the openings 202, 202' outside the print area, mostly behind the guide plate 2. A surface part 200, 200 'of the conveyor belts 201, 201' with the Openings 202, 202 'are then immediately in front of the detection area of the sensor 8. The surface part 200, 200 'of the conveyor belts comes into contact with the surface part 300 of the print carrier 3, if the printing medium 3 is put on by the - not shown here - Anlegehilfsvorrichtung 30 was detected by the sensor 8 and the Conveyor belts 201, 201 'are set in motion.

A negative pressure is created by means of the transport and guiding means 20, 20 ' on both sides of the printing area on parts of the print carrier surface exercised, the first means of transport and guidance 20 between the holding rails 205 and 208 along the line l-l ' an increase h with respect to the guidance of the sucked parts of the Surface 300 of the print carrier 3 causes while the further Transport and guidance means 20 'the parts of the surface 300 of the Holds print carrier 3 near the contact edge 31.

The width of the conveyor belt 201 'or the further transport and Guide means 20 'is max. 8 mm. The recess 21 for the Inkjet print head 4 starts at a distance of about 9 mm from the Application edge 31 on the surface of the conveyor belt 10 it is ensured that the pressure is already at a distance of approx. 10 mm from the contact edge 31 on the surface 300 of the print carrier 3 can be done. Such a requirement exists, for example, with Franking of postal items.

The width of the conveyor belt 201 or the first conveyor and In contrast, guide means 20 can vary. When cutting along the line l-l 'through the first transport and guiding means 20 of the Auxiliary device on the guide plate, there is again a corresponding Representation as was shown for the first variant in FIG. 3a.

3b is a section through the line A-A 'of the auxiliary device shown the guide plate. On the axis 28 of the drive 25 a drive roller 19 'attached, which the conveyor belt 201' drives. The conveyor belt 201 'is around the guide plate 2 stored around by means of guide rollers 18 'and has a predetermined Length. It lies on the suction housing 204 'or the perforated plate 206' of the transport and guiding means 20 'of the auxiliary device in an air-closing manner on. One side of the conveyor belt 201 'without the Openings 202 'lie in the pressure area between the holding rails 205 and 208 and closes the suction space 203 'or the openings of the Perforated plate 206 'until the conveyor belt 201' from the drive 25 in a synchronous movement to the transport movement of the conveyor belt 10 is offset. A shaft 24 connects the axis 28 of the Drive 25 with the axis 29 of the drive roller 19 for the Conveyor belt 201. Both axes 28 and 29 are at an angle β to each other. The shaft 24 can be flexible or as a cardan shaft be trained.

The conveyor belt 201 'runs over guide rollers 18' and one Drive roller 19 'at the same transport speed as that - shown in Fig. 1b - conveyor belt 10, as soon as by means of a sensor 8 Print carrier 3 is detected. Preferably both drives of the Transport means 1 and the auxiliary device coupled together. On Drive 25 of the auxiliary device for the drive roller 19 'works synchronized with the drive of the drive roller 11 '. The drive 25 is for this connected to a controller 40, which has a corresponding Switching or clutch controls.

4b shows a schematic arrangement for guiding the air on the guide plate and controlling it for the second variant of the auxiliary device according to the invention. The air is guided on the guide plate 2 by means of the following arranged on the one hand, as already explained in connection with the first variant with reference to FIG. 4a. The air is guided from a suction space 203 of the transport and guide means 20 of the auxiliary device via the suction channel 17, the connector 16, the pressure hose 15 to the controlled valve 14, the pressure hoses 13 and 27 to the motor suction pump 12 with a means 121 which accelerates ink drying the air flow from an intake space 203 'of the further transport and guide means 20' of the auxiliary device arranged on the guide plate 2 near the contact line 31, also via an intake duct 17 ', a connector 16', a pressure hose 15 'to the uncontrolled valve 14' and the pressure hoses 13 'and 27 to the motor suction pump 12.
A hose connector 26 connects the pressure hoses 13 and 13 ', which are brought in by the valves 14, 14' of the two transport and guide means 20 and 20 ', with the pressure hose 27 to the motor suction pump 12. Alternatively, a second motor suction pump 12' can also be used , then the hose connector 26 and the pressure hose 27 to the motor suction pump 12 are omitted. It is further provided that the means 121 accelerating the ink drying is a blower means arranged downstream of the ink jet print head 4 at the level of the recess 21 of the guide plate 2.

The controller 40 is on the input side with the sensors 7 and 8 as well on the output side with the drive 25, with the controllable valve 14 and connected to the motor suction pump 12. With one over one increases the predetermined negative pressure the valve 14 secondary air from the environment. The size of the predetermined vacuum can be controlled by the controller. The uncontrolled valve 14 'draws secondary air from the environment when one fixed size of the negative pressure is exceeded, the fixed negative pressure is always stronger than that with the controllable valve 14 set negative pressure. The controllable valve 14 is controlled so that the effort to overcome that exercised by the transport and guiding means 20 The static friction force decreases as the transport progresses is, so that neither tearing nor lifting the print carrier can be done, just tightening the surface of the Print media results.

If for the device according to the invention shown in Fig. 1b according to the second variant, with an auxiliary device on one negatively inclined with respect to the vertical to the reference plane Guide plate, the inclination angle α is further increased in the extreme case, another variant with horizontal pressure carrier transport. FIG. 5 shows such a further variant horizontal print carrier transport. Orthogonal to the guide plate 2, which has an auxiliary device 20, 20 'is a means of transport 10 arranged, preferably a circumferential conveyor belt 10. Die Auxiliary device does not exert any counter pressure on the Print carrier.

With different thicknesses and masses of the letters to be conveyed, a force F to be absorbed by the printing station occurs at a high transport speed V: F = m * a = m * V / t

According to this equation, large forces F would be required for large masses. When pressed against a guide plate by means of a resilient counter pressure device, disturbing vibrations could thus be transmitted. According to the invention, there is again no need for a counterpressure device, and only a pilot control by means of a specially designed positioning aid device 30 'is additionally required, which carries out a rough adjustment of the thickness and an adaptation of the angle of attack γ and the angle of inclination α. The letter then comes to rest against the guide plate 2, the sensor 8 of which detects the letter. The controller 40 initiates the transport through the auxiliary device according to the invention which sucks the letter. This is constructed accordingly and, like the second variant, is equipped with two transport and guide means 20, 20 ', which, however, must exert a greater force under the condition of horizontal transport. The letter surface is raised in relation to the letter content in the printing area on the guide plate 2, whereas the letter bottom and letter content remain essentially at the level which is predetermined by the angle of inclination γ and possibly the angle of inclination α of the positioning aid device 30 '. For precontrol, the zx transport level contacting device 30 'can be adjusted up and down in the y direction in the conveyor belt - in a manner not shown. The advantage is that the letter no longer has to be accelerated to the guide plate in the printing station and then braked, and also does not need to be pressed against the guide plate 2 by means of a counterpressure device.
This prevents vibrations. Only the surface of the envelope or comparable print carrier should reach the guide plate. The massive filling of the envelope should not hit the guide plate. To maintain these conditions, taking into account the angle of attack γ, the precontrol and acceleration are adjusted to one another in the application aid device 30 '. This adjustment is carried out in such a way that each printing medium is always brought to a predetermined parabolic trajectory P by the application aid 30 '. The printing station is reached at a point near the apex of the parabolic trajectory P. By suction on the two transport and guiding means 20, 20 ', the surface is tightened again, which the ink jet print head 4 is intended to print in a non-contact manner through the recess 21. The exhaust air generated during suction can be used again for drying in order to improve the smudge resistance of the fresh impression. A positive increase ^h / ₂ in the guidance of the transport and guidance means 20 and a negative increase ^{h '} / ₂ in the guidance of the transport and guidance means 20' now act simultaneously in opposite directions and thus lead to tightening. The conveyor belts 201 and 201 'are consequently each arranged obliquely at an angle of ^β / ₂ to the direction of transport. The conveyor belt 10 is now on the side.
The letter edge presses on its surface due to the guidance of the transport and guide means 20 'with a negative increase ^h' / ₂ .

The controllable valves 14 and 14 'are controlled so that the effort to overcome by the transport and Guide means 20 and 20 'exerted static friction progressive transport are getting smaller, but the Holding force for the contact of the letter surface with the guide plate 2 until printing is completed. In cooperation with the persistence of inert masses, which by the Pre-control using the specially designed attachment aid 30 'accelerated, is at a high transport speed only an order of magnitude higher suction power due to the Motor suction pump 12 to provide. According to the invention Auxiliary device 30 'a parabolic trajectory P with a largest Approaching the center of the guide plate. It is the controller 40 connected to sensors 7, 8 and actuators and for synchronization all transport movements are trained and programmed accordingly.

Between the positioning aid 30 'and the guide plate 2 or in the application aid device 30 'or in the guide plate 2 a - not shown - device for removing dust, fibers i.a. disruptive particles from the surface to be printed be provided. This device preferably reworks a vacuum cleaner principle and is via a hose, a uncontrolled valve and a filter as well as via the connector also 26 connected to the motor suction pump 12 or has one separate drive.

The invention is not based on the present embodiment limited because obviously other arrangements or Execution of the method developed for other facilities or can be used by the same basic idea of Invention based on the appended claims become.

Claims (20)

Device for transporting and printing on print media, with an inclined guide plate (2) and a means of transport (1) orthogonal to this guide plate (2) and with an auxiliary device, an ink jet print head (4) controlled by a controller (40) in a recess (21) of the guide plate (2) is fixedly arranged during printing and the recess (21) is designed in such a way that the print carrier (3) is exposed downstream with the printed area, characterized in that it is transported by the transport means (1) Pressure carrier (3) rests without jamming on an auxiliary device which has a rising guide and permits defined slip of the surface of the pressure carrier (3) directed perpendicular to the surface of the means of transport. Apparatus according to claim 1, characterized in that the guide plate (2) is inclined at a positive angle α from the perpendicular and that the auxiliary device has a first transport and guide means (20) which is arranged on the guide plate (2) in that the first transport and guide means (20) of the auxiliary device is equipped with a transport means (201) which exerts a negative pressure, so that an incline of the guide means (204) is provided on the guide plate (2), with the pressure carrier (3) being transported by means of the transport means (1) and the first transport and guide means (20), due to the incline of the guide means of the guide plate, the distance of the parts of the print carrier surface remote from the printing area to the near the contact edge (31) of the print carrier (3) on the surface of the Transport means (1) lying parts of the print carrier surface to enlarge a desired tightening under heavy to achieve force influence on the print carrier. Apparatus according to claim 1, characterized in that the guide plate (2) is arranged vertically to the reference plane or is inclined from the plumb line and that the auxiliary device has a first transport and guide means (20) and a further transport and guide means (20 '), which are arranged on the guide plate (2) and exert a negative pressure on both sides of the printing area on parts of the print carrier surface, the first transport and guide means (20) exerting a negative pressure on parts of the print carrier surface remote from the printing area and increasing with a rising in the transport direction Guide is equipped and the further transport and guide means (20 ') exerts a negative pressure on parts of the print carrier surface near the contact edge (31) of the print carrier (3) on the transport medium surface and parallel to the transport direction of the transport medium (1), so that the tensioning of the print surface to be printed che is achieved by both aforementioned transport and guide means of the auxiliary device. Device according to one of claims 1 to 3, characterized in that the guide plate (2) is preceded by a support device (30) for adapting the angle of inclination α of the guide plate (2). Device according to one of claims 1 to 3, characterized in that the guide plate (2) has contact rails 232, 233 and the auxiliary device holding rails 205, 208, both on both sides before and after the recess (21) in the guide plate (2) for Ink jet print head (4) support rails (205, 208) of the auxiliary device bear against the respective contact rail (232, 233) of the guide plate (2) and that the first transport and guide means (20) by fastening to the support rails (205, 208) in a defined manner Distance to the contact edge 31 is held and a conveyor belt (201) guided by means of guide means (204 to 206) at an angle β, so that there is an increase h in the guidance of the pressure carrier (3) in the transport direction along the line II 'between the two holding rails (205 and 208) results in that the transport and guiding means (20) has means (200 to 204, 206) and is connected to an intake duct (17) in order to exert a negative pressure is. Device according to one of the preceding claims 1 to 5, characterized in that the transport and guide means (20) of the auxiliary device has a drive (25) which is controlled by the controller (40), that the conveyor belt (201) via guide rollers (18) and a drive roller (19) rotates and transports at the same transport speed as a conveyor belt (10) of the transport means (1) as soon as a contact of the pressure carrier (3) with the auxiliary device is detected by means of a sensor (8). Device according to one of the preceding claims 1 to 6, characterized in that the drive of the transport means (1) and the drive (25) of the auxiliary device are coupled to one another so that the drive (25) of the drive roller (19) in the auxiliary device is synchronous to drive the drive roller 11 'of the transport means (1) works as soon as a pressure carrier (3) reaches the sensor (8). Device according to one of the preceding claims 1 to 7, characterized in that the drive (25) has an axis (28) which is connected to the axis (29) of the drive roller (19) for the conveyor belt (201) via a shaft (24 ) is connected, which compensates for the angle β between the axes during driving. Apparatus according to claim 8, characterized in that the shaft (24) is designed as a flexible shaft or cardan shaft. Device according to one of the preceding claims 1 to 6, characterized in that the conveyor belt (201) has a predetermined length and a surface area (200) with openings (202) for sucking in the pressure carrier surface (300), that the suction channel (17) has a Suction chamber (203) in the suction housing (204) of the transport and guide means (20) of the auxiliary device connects via a connection piece (16) to a pressure hose (15) which applies a predetermined vacuum p, the vacuum p through the perforated plate (206) is passed to the openings (202) of the conveyor belt (201) when the conveyor belt (201) is driven after detection of a print carrier (3) and the conveyor belt (201) is transported so far without detection of a print carrier (3) that it closes all openings in the perforated plate (206). Apparatus according to claim 10, characterized in that the length of the conveyor belt (201) corresponds to the sum of the print carrier length of the shortest print carrier (3) and the shortest distance between two successively supplied print carriers (3) and that the drive (25) is controlled by the controller (40) is controlled accordingly, so that the conveyor belt (201) is stopped again after one revolution if no further pressure medium is detected or that the controller (40) increases the negative pressure and the conveyor belt (201) in a transport movement along the guide Line II 'offset when a further print carrier (3) is detected by means of sensor (8). Device according to one of the preceding claims 1 to 11, characterized in that the control (40) controls the negative pressure by means of a valve (14) and a motor suction pump (12) so that the effort required to overcome the transport and guiding means ( 20) the static frictional force exerted in the transport direction becomes less and less as the transport proceeds, so that lifting of the print carrier is avoided and the surface of the print carrier is tightened. Device according to Claim 12, characterized in that the control (40) is connected on the input side at least to the sensor (8) and on the output side to the controllable valve (14) and the motor suction pump (12) and the pressure start from the control (40) accordingly the transport speed is calculated and that the controllable valve (14) draws secondary air from the environment in the event of a negative pressure increase exceeding a predetermined negative pressure, the size of the predetermined negative pressure being controllable by the controller (40). Apparatus according to claim 13, characterized in that the following means arranged one after the other guide air from an intake space (203) of the first transport and guide means (20) of the auxiliary device via the intake duct (17), the connecting piece (16) and the pressure hose ( 15) to the controlled valve (14), the pressure hoses (13 and 27) to the motor suction pump (12) using a means (121) which accelerates ink drying. Device according to one of the preceding claims 1 to 14, characterized in that an additional sensor (9) is arranged at the print head at the level of the contact edge (31) of the print carrier (3) on the conveyor belt surface of the first transport means (1) Control (40) is queried in order to report a possible lifting of the pressure carrier (3) from the conveyor belt surface of the first means of transport (1), in order then to reduce the suction force F _s accordingly by reducing the negative pressure p by means of the controllable valve (14) becomes. Device according to claims 3 to 14, characterized in that a further drive roller (19 ') of the further transport and guide means (20') is fastened on the axis (28) of the drive (25), which further transport belt (201 ') which is mounted around the guide plate (2) by means of guide rollers (18') and has a predetermined length, that on the suction housing (204 ') or the perforated plate (206') of the further transport and guide means ( 20 ') of the auxiliary device rests air-tight, one opening-free side of the conveyor belt (201') lying in the pressure area between the holding rails (205 and 208) and closing the suction space (203 ') or the openings of the perforated plate (206') as long as until the further conveyor belt (201 ') is set by the drive (25) in a synchronous movement to the transport movement of the conveyor belt (10) that an uncontrolled valve (14') is provided which draws secondary air from the environment when a e fixed size of the negative pressure is exceeded, the fixed negative pressure is always stronger than the negative pressure set by means of the controllable valve 14 and that by successive means arranged an air flow from the suction chamber (203 ') close to the guide plate (2) Starting from the contact line (31), further transport and guide means (20 ') are arranged, via an intake duct (17'), a connector (16 '), a pressure hose (15') to the uncontrolled valve (14 ') and the pressure hoses (13 ') or (27) to the motor suction pump (12) with which the ink drying accelerating means (121) takes place. Device according to claim 16, characterized in that the pressure hoses (13 ', 13) and (27) are connected to one another via a hose connector piece (26) or are connected separately to a motor suction pump (12). Apparatus according to claim 16, characterized in that the means (121) accelerating the ink drying is a blower means arranged downstream of the current at the recess (21) of the guide plate (2) and connected to the motor suction pump (12) . Apparatus according to claim 4, characterized in that for the adaptation from a horizontal to a vertical transport of a pressure carrier (3) or vice versa or from an inclination of the guide plate (32) to another inclination of the guide plate (2), a positioning aid device (30, 30 ') for the adaptation of the angle of inclination α. Apparatus according to claim 19, characterized in that for the adaptation of the angle of inclination α slide rails (33) of the guide plate (32) are provided.

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