EP1497136A1

EP1497136A1 - Printing device and method for printing an information carrier

Info

Publication number: EP1497136A1
Application number: EP03722392A
Authority: EP
Inventors: Willi Sautter
Original assignee: Bizerba SE and Co KG
Current assignee: Bizerba SE and Co KG
Priority date: 2002-04-23
Filing date: 2003-04-03
Publication date: 2005-01-19
Anticipated expiration: 2023-04-03
Also published as: ATE512801T1; WO2003091036A1; EP1497136B1; JP2005523189A; US6977668B2; DE10218842B4; US20050024472A1; DE10218842A1; ES2367983T3; AU2003229601A1

Abstract

To improve a printing apparatus for printing an information carrier on a carrier tape, comprising a printing head, a first transport device by means of which the carrier tape is guidable past the printing head, and a second transport device by means of which a transfer tape is guidable past the printing head and which upon activation by the printing head causes an information carrier to be printed, with the contact pressure of the printing head on the transfer tape and on the carrier tape and the transfer tape feed by the second transport device being controllable in such a manner that the carrier tape is guidable past the printing head with a difference in speed relative to the transfer tape, such that this is of space-saving design and operates effectively, provision is made for the printing head to be pneumatically liftable away from the transfer tape.

Description

DESCRIPTION

Printing device and method for printing an information carrier

The invention relates to a printing device for printing an information carrier on a carrier tape, comprising a print head, a first transport device, by means of which the carrier tape can be guided past the print head, and a second transport device, by means of which a transfer tape can be passed past the print head, which, when activated causes an information carrier to be printed on by the printhead, the contact pressure of the printhead on the transfer ribbon and on the carrier ribbon and the transfer ribbon feed being controllable by the second transport device such that the carrier ribbon can be guided past the printhead at a speed difference relative to the transfer ribbon.

Such printing devices are known for example from DE 35 10 260 C2 or DE 43 32 562 AI.

Once a transfer ribbon area of a transfer ribbon has been activated, which may be a thermal transfer ribbon, for example, cannot be used for printing. If the transfer ribbon is guided past the print head synchronously with the carrier ribbon, even if no areas are to be printed, then there is an unnecessary transfer ribbon consumption, since the transfer ribbon was not activated and nevertheless with the used transfer ribbon is wound up. With appropriate control of the transfer ribbon feed in such a way that there is a speed difference relative to the continued carrier ribbon during a non-printing mode, the transfer ribbon in particular being stopped relative to the print head, the transfer ribbon consumption can be minimized.

The invention has for its object to improve a printing device of the type mentioned so that it can be trained to save space with effective operation.

This object is achieved according to the invention in the above-mentioned printing device in that the print head can be lifted pneumatically away from the transfer belt.

With such a pneumatic control of the lifting of the print head, it can be achieved that minimized masses have to be moved. This enables very short reaction times to be achieved and the system can be set up to save space. It can therefore be easily integrated, for example in a labeling machine. Due to the minimization of the mechanical coupling of the moving parts, the wear and thus the susceptibility to faults is minimized.

/

The printing device according to the invention can be used if the information carrier is an element separate from the carrier tape, for example a self-adhesive label which is arranged on the carrier tape, or if the carrier tape itself forms the information carrier in the so-called "linerless" technology. In particular, it is provided that the print head can be lifted away from the transfer belt and thus also from the carrier belt by means of a controllable air pulse or sequence of air pulses. Such a controllable air pulse or such a controllable air pulse sequence can be produced in a simple manner by means of a controllable passage valve which is connected to a pressure source. The signal level (amplitude) of the air pulse can be set via the pressure source itself. For example, the passage valve can be controlled via a control device of the printing process, which can then cause the print head to be lifted when larger areas that are not to be printed are present.

The air pulse or the air pulse sequence can advantageously be time-controlled in order to obtain a minimized transfer ribbon consumption when the information carrier is printed on the carrier ribbon.

Short switching times, i.e. H. A high switching frequency can be achieved if the print head is connected to a movable element which can be pressurized in order to be lifted off the carrier tape. This element is then moved by appropriate pressurization, which in turn causes this movement to lift the print head. This enables short response times to be achieved.

In principle, the movable element can be a compressed air cylinder. It is particularly advantageous if the element which can be pressurized is a membrane. This can be done with minimized inertia train so that the reaction times when pressurizing are minimized. It has been shown that lifting the print head in the order of 0.5 mm is sufficient to reduce the contact pressure sufficiently. Such a relative movement can be achieved by pressurizing a membrane with the described advantages, with short reaction times being guaranteed.

The printhead is advantageously arranged such that it can be pivoted, so that a torque can be exerted via the pressurizable element, which causes the printhead to be lifted away from the carrier tape.

Preferably, a pneumatic pressurizing surface is arranged on a print head holder for moving the print head between the print head and a pivot axis of the print head holder, in order to be able to carry out a lifting movement without disturbing the printing process.

It is also expedient if the print head is arranged pretensioned with respect to a guide surface for the carrier tape. This defines a basic position of the print head, namely the basic position suitable for the printing mode. Through an active process, namely the emission of an air pulse, the print head is then pivoted away and automatically returns to its basic position after the application of pressure has ended. This ensures the actual task of the printing device, namely the printing of the information carrier.

The biasing force acts against a lifting force for the printhead away from the guide surface so as to ensure that the printhead returns to the basic position after the pressurization has ended.

In order to set the positions of the printhead in a defined manner, a stop for the printhead is advantageously provided for movement away from and towards the carrier tape; In this way, the maximum possible distance between the print head and the carrier tape can be set.

The stop of a pneumatic loading surface of a print head holder is advantageously arranged opposite one another in order to achieve a space-saving arrangement.

Furthermore, a stop for the movement of the print head on a guide surface of the carrier tape is provided in order to achieve a defined reaching of the basic position for the print mode when the print head is reset after a lifting movement.

The stop advantageously lies in the vicinity of the guide surface or forms at least part of the guide surface in order to be able to restore the basic position in a defined manner.

It is particularly favorable if a stop is provided with a damping element, for example a piece of felt, in order to avoid hard bumping and thus to increase the service life of the printing device.

It is advantageously provided that a guide surface for the carrier tape is formed during printing on a pull-off element for the carrier tape. On such a peeling element, the carrier tape is deflected after the information carrier has been printed in order to lead the printed information carrier out of the printing device, so that a user can remove the information carrier.

It is particularly advantageous if the movement of the print head can be switched with a switching frequency of 80 Hz or faster. Such switching frequencies can be achieved in the pneumatic actuation of the print head, in particular via a print head holder and a print cylinder, which is in particular a membrane.

In order to achieve a defined unwinding of an unused transfer ribbon and a defined winding of a used transfer ribbon, the second transport device advantageously comprises a transfer ribbon unwinder and a transfer ribbon winder.

It is particularly advantageous if the transport of the transfer belt can be stopped pneumatically by the second transport device. The further transport of the transfer ribbon in the printing device can then be stopped simultaneously with the lifting movement of the print head with respect to the transfer ribbon. In this way, the second transport device can then be synchronized with respect to the transport of the transfer belt with the movement of the print head. It is very particularly advantageous if an air pulse or an air pulse sequence for moving the print head away from the carrier tape simultaneously brings about braking of the movement of the transfer tape. The air pulse generated via a passage valve or the generated air pulse sequence can then simultaneously serve to lift the print head and to stop the transport of the transfer ribbon. This in turn enables these two processes to be synchronized automatically.

In particular, it is provided that the air pulse or the air pulse sequence actuates a brake of a transfer ribbon unwinder and / or transfer ribbon winder, so as to block the further transport of the transfer ribbon past the print head.

In order to unwind the unused transfer ribbon and wind up the used transfer ribbon, the transfer ribbon winder is alone or the transfer ribbon winder and the transfer ribbon winder are driven directly. It is preferably the case that the transfer ribbon winder is driven directly, while the other winder is then driven indirectly via the transfer ribbon.

The object mentioned at the outset is achieved, alone or in combination with the features already explained, in that a drive of the second transport device for the movement of the transfer belt is designed as a slip drive. With such a slip drive can be Minimize axial bearing forces on rotating parts. Since a flexible design is possible, no high mechanical precision with regard to the bearing and the drive is required, so that the corresponding drive can be implemented inexpensively. Furthermore, a self-aligning contact of the relevant friction surfaces can be achieved, so that a high stability of the friction torque is achieved.

In particular, a transfer belt winder and / or a transfer belt winder and in particular the directly driven winder is driven at overspeed. The desired speed for the winder is then set via a corresponding slip, which is particularly adjustable.

Such a slip drive can be realized in an advantageous manner if it comprises an element, in particular a directly driven element, which is coupled to a transfer ribbon receptacle, the coupling being non-positive. As a result, the transfer belt holder can be rotated via the coupling via the driven element. Due to the non-positive coupling, however, a certain slip can be achieved, through which, for example, frictional torque stability can be achieved.

Such a frictional coupling can be achieved in a simple manner if the driven element and the transfer ribbon receptacle are magnetically coupled. For example, the transfer ribbon receptacle has a plurality of receptacles for magnets facing the driven element. The magnets can be electromagnets or permanent magnets. The slip torque can then be adjusted by equipping or connecting magnets in the magnet receptacles. As a result, an adaptation, for example, to the material of the transfer belt and / or the carrier belt can also be carried out by subsequently fitting or removing magnets. If, for example, N receptacles are provided which can be equipped with M magnets, then an N x M gradation with regard to the setting of the slip torque can be achieved.

Preferably, either the transfer ribbon winder is driven directly or the transfer ribbon winder. It is advantageous if the non-(directly) driven winder comprises a slip clutch, by means of which a transfer ribbon receptacle can be fixed in a rotationally fixed manner with respect to a housing of the printing device. The slip clutch can be designed so that the transfer belt holder rotates when the other winder is driven. The torque for rotating the transfer belt holder is transmitted through the transfer belt. However, if the drive is then stopped, the slipping clutch also causes the transfer ribbon receptacle to be stopped with respect to the housing via the rotationally fixed fixation. This in turn keeps the transfer belt taut even when the transport is stopped, so that sagging or folding or kinking and the like is avoided.

In particular, the fixation is non-positive and preferably via magnetic forces. For this purpose, similar to that described above in connection with the Sehlupf drive, the transfer ribbon holder is provided with a plurality of magnetic holders in which magnets can be used. The fixing force in turn can be adjusted by equipping or shading magnets in the magnet receptacles. The torque that is required to rotate the transfer belt holder can be set using the fixing force alone.

It is expedient if a shaft stub, which is arranged in a rotationally fixed manner, in particular with respect to a housing of the printing device, is provided for the transfer ribbon winder and / or the transfer ribbon winder on which a sleeve for receiving the transfer ribbon is rotatably seated. This allows rigid axles to be reached, with regard to which tensile forces are minimized.

The invention further relates to a method for printing on recording media on a carrier tape by means of a print head, which activates a transfer tape.

The object of the present invention is to provide a method with minimized reaction times.

This object is achieved in that the print head can be lifted pneumatically away from the transfer belt.

The method according to the invention has the advantages already explained in connection with the printing device according to the invention. Further advantageous embodiments of this method have also already been explained in connection with the device according to the invention. In particular, it is advantageous if an air pulse or an air pulse sequence which lifts the print head away from the transfer belt stops the transport of the transport belt.

The following description of preferred embodiments serves in conjunction with the drawing to explain the invention in more detail. Show it:

Figure 1 is a plan view of an embodiment of a printing device according to the invention;

Figure 2 is a schematic representation of elements of the printing device according to Figure 1 to explain its operation;

FIG. 3 shows a perspective partial sectional view of a transfer belt

Aufspulers;

FIG. 4 shows a perspective partial sectional view of a transfer belt

off reel;

Figure 5 is an enlarged view of area A of Figure 3 and

6 shows a sectional view of the transfer ribbon rewinder according to FIG

3 along the line 6-6. An embodiment of a printing device according to the invention, which is designated as a whole in Figure 1 with 10, comprises a stable housing base 12 which is designed so that it can absorb the forces that occur. This housing base 12 holds a housing (not shown in the drawing).

The printing device comprises a first transport device, designated as a whole by 14, for transporting a carrier tape 16 with information carriers to be printed through the device.

Furthermore, a second transport device, designated as a whole by 18, is provided, via which a transfer belt 20 can be transported through the device.

Carrier belt 16 and transfer belt 20 are guided through the respective transport devices 14 and 18 such that they converge in a printing area 22, so that information carriers, for example labels, can be printed on the carrier belt 16 when the transfer belt 20 is activated by a print head 24.

The transfer ribbon 20 is, in particular, an ink ribbon or a thermal transfer ribbon. In this case, the print head 24 is designed as a thermal print head, which has individually controllable needle-shaped heating elements which bring about a transfer of color from the transfer belt 20 to the information carrier on the carrier belt 16. The first transport device 14 for the carrier tape 16 comprises a receptacle 26 for a carrier tape roll 28, from which carrier tape 16 can be unwound for feeding to the print head 24. The receptacle 26 is in particular not driven, with an axis of rotation 30 for the carrier tape roll 28 lying transversely and in particular perpendicular to the housing base 12 (perpendicular to the plane of the drawing in FIG. 1). The carrier tape is unwound tangentially from the carrier tape roll 28 and aligned via deflection rollers 32, 34 so that it can be fed to the print head 24, the print head 24 being arranged in particular in a corner region of the housing base 12, so that an information carrier 36, for example a Label, can be easily removed after printing and sufficient space is provided for receiving the carrier tape roll 28. For example, the deflection rollers 32, 34 are arranged such that the carrier tape is guided essentially parallel to a housing base side after passing these deflection rollers 32, 34.

The carrier tape 16 is deflected via a further deflection roller 38 in such a way that it can be guided past the print head 24 for printing on the information carriers 36. A guide surface 42 for guiding the carrier tape 16 during printing is formed on a pull-off element 40. The pull-off element 40 is designed in such a way that the direction of the carrier tape is changed after printing and the printed information carrier can be removed from a housing slot.

The carrier tape is guided via further deflection elements 46, 48 to a carrier tape winder 50, which receives the carrier tape after the printed information carrier 36 has been detached. This carrier tape winder 50 is arranged in an area 57 of the housing base 12 which lies between the receptacle 26 for the carrier tape roll 28 and the printing area 22 in order to provide a corresponding space for winding the carrier tape 16.

In principle, it is possible that removable information carriers 36 are arranged on the carrier tape 16, which are printed on, or that the carrier tape can be printed directly using the so-called linerless method (in this case, the carrier tape is not the carrier of information carriers, but the information carrier itself). , In the linerless case, the printing device must be configured as described in EP 0 758 979 B1, to which reference is hereby expressly made. In particular, means are then provided, which are arranged after the print head 24 and lie next to a printing roller in order to strip a section of the (adhesive-coated) carrier tape 16 from the printing roller, so that the carrier tape 16 with the information printed on the side opposite the adhesive layer can be removed from the printing device 10.

The second transport device 18 for transporting the transfer belt 20 comprises a rotatable transfer belt unwinder 52 and a rotatable and in particular directly driven transfer belt unwinder 54. The transfer belt 20 is unwound as a transfer belt roll 56 from the transfer belt unwinder 52 and is thereby approximately parallel to the carrier tape 16 to the print head 24, with a deflection taking place on a deflecting element 59 around the transfer ribbon 20 and the carrier tape 16 with one another to be able to bring in contact. The transfer ribbon 20 is then guided past the print head 24, and used transfer ribbon 20 is wound up by the transfer ribbon winder 54.

The axes of rotation 58 and 60 of the conveyor belt unwinder 52 and of the conveyor belt unwinder 54 are parallel to one another essentially perpendicular to the housing base 12 and thus also parallel to the axis of rotation 30 of the receptacle 26 for the carrier tape reel 28. The directions of rotation of the transfer belt winder 54 and transfer ribbon unwinder 52 are directed in opposite directions.

The transfer ribbon 20 and the carrier ribbon 16 are guided synchronously with one another for printing, so that during the activation of the print head 24 there is essentially no relative speed between the carrier ribbon 16 and the transfer ribbon 20. For the printing of an information carrier 36, the transfer ribbon is acted upon by the print head 24 in a partial area. This pressurized section is removed after printing, i. H. fed to the transfer ribbon winder 54, since this area can no longer be used for printing.

Basically, it is only necessary to guide the transfer belt 20 and the carrier belt 16 synchronously during printing. In order to avoid excessive consumption of the transfer ribbon 20, it is provided according to the invention that the transfer ribbon transport is braked and in particular stopped by the second transport device 18 if no printing operation is to be carried out while the carrier ribbon 16 passes the print head 24; this is particularly the case if an information carrier 36 has larger areas which are not to be printed on. So that the transport of the transfer belt 20 can be stopped when the carrier belt 16 is transported further, a speed difference between the carrier belt 16 and the transfer belt 20 must be able to form. For this it is necessary that the contact pressure of the print head 24 on the transfer belt 20 to the carrier belt 16 is reduced. According to the invention, it is now provided, as shown in FIG. 2, that the print head 24 is arranged on the housing base 12 so as to be pivotable via a print head holder 62 by means of a pivot bearing 64. A pivot axis 66 is arranged parallel to the axes of rotation 58, 60. The printhead holder 62 with the printhead 24 firmly attached to it can be pivoted pneumatically, ie by pressurized air, away from the transfer belt 20. For this purpose, an overpressurization device 68 is provided, to which a controllable passage valve 70 is coupled. A pressure line 72 leads from this passage valve to an element 74 which can be subjected to pressure and which is in particular a membrane. This pressurizable element 74 is movable in such a way that a swiveling movement of the printhead 24 away from the carrier tape 16 can be initiated by this with appropriate pressurization. For this purpose, the element 74 which can be pressurized is coupled to the printhead holder 62 via a pneumatic actuating surface, in order to bring about a movement of the pressure-acting element 74 by means of a pivoting movement of the printhead holder 62.

A holding element 76 is rigidly seated on the housing base 12 and provides a stop surface 78 for the movement of the print head holder 62 in order to limit the pivotability of the print head 24 away from the carrier tape 16. This stop surface 78 is particularly arranged so that it is the pneumatic pressure surface of the print head holder 62, via which the pressurizable element 74 acts thereon, is opposite.

The stop surface 78 is provided with a damping element 80, for example a piece of felt, in order to avoid a hard impact.

A height distance 82, in which the print head 24 can be lifted from the carrier tape 16, is in the order of magnitude of approximately 0.5 mm or less, for example.

A spring 84 is seated on the holding element 76, which biases the print head holder 62 in such a way that the print head 24 presses the transfer ribbon 20 against the carrier ribbon 16 with the pressing force required for printing. When the print head holder 62 is pivoted away from the carrier tape 16, the spring force of the spring 84 must be overcome. If the pressurization is removed, the spring 84 acts as a return spring with a return force which moves the print head holder 62 with the print head 24 in the direction of the carrier tape 16 and presses the transfer tape 20 against the carrier tape 16.

The pneumatic pressure surface of the print head holder 62 is arranged between a pressure surface of the spring 84 on the print head holder 62 and the pivot axis 66 of the print head holder 62. The spring 84 is also arranged such that the contact pressure of the print head 24, which is then exerted by the transfer belt 20 on the carrier belt 16, acts on the area of the guide surface 42 of the carrier belt on the pull-off element 40. In particular, it is provided that the pull-off element 42 is designed as a stop for the print head 24 with a damping element 86 which lies on the guide surface 42 or even forms part of this guide surface 42. This damping element 86 prevents the print head 24 from striking hard against the pull-off element 40 when the print head holder 62 is reset.

A pressure line 88 also leads from the overpressure application device 68 to the transfer belt winder 54. By applying pressure to the pressure line 88, the transport belt winder 54 can be braked and in particular stopped, so that the further transport of the transfer belt 20 is stopped.

The passage valve 70 can be controlled, ie in particular opened and closed, by means of a control device for the printing process (not shown in the drawing). The control takes place temporally, ie if a larger area that is not to be printed comes through, the passage valve 70 is opened so as to pressurize the pressure lines 72 and 88. As a result, an air pulse or an air pulse sequence is transmitted on these pressure lines 72 and 88, which initiate the corresponding control processes for the print head 24 and the conveyor belt winder 54. Depending on the set volume flow and the set pressure, very fast switching processes can be implemented with a switching frequency in the order of 80 Hz or faster. In order to adjust the volume flow and pressure, it can also be provided that a throttle is connected upstream (not shown in the drawing). If the passage valve 70 is switched to passage, then the corresponding air pulse or pressure pulse acts on the membrane 74, which in turn acts on the pneumatic pressure surface of the print head holder 62 and pivots it away from the carrier tape 16, so that the contact pressure from the transfer tape 20 is applied the carrier tape 16 is reduced.

Furthermore, this air pulse or pressure pulse acts on the pressure line 88 and brakes and in particular stops the transfer ribbon winder 54, so that the further transport of the transfer ribbon 20 is stopped.

By means of the pneumatic control of the swiveling movement of the print head 24 and the braking of the driven transfer ribbon winder 54, a transfer ribbon economy circuit can be implemented, which reacts quickly with minimal mechanical coupling and minimized moving mass; the corresponding economy circuit can be used effectively and is space-saving and can therefore be easily integrated into a housing.

As shown in FIG. 3, the conveyor belt winder 54 comprises a shaft stub 90 which is arranged rigidly in a rotationally fixed manner with respect to the housing base 12. On the stub shaft 90, a sleeve 92 is rotatably seated. H. the sleeve 92 is rotatably supported on the stub shaft 90. This sleeve 92 in turn forms a receptacle for the (used) transfer belt 20.

A brake 94 is arranged on the shaft stub 90, which is, for example, a piston brake which is connected to the pressure line 88 and which can be actuated by pressure. For example, the brake 94 includes a piston 97 which, when subjected to an air pulse or a sequence of air pulses, clamps the sleeve 92 with the shaft stub 90, so that the rotatability of the sleeve 92 relative to the shaft stub 90 is blocked.

A disc-shaped flange 96 which faces the housing base 12 and which has a plurality of receptacles 98 for magnets 100 faces the housing base 12 (FIGS. 3, 5, 6). These receptacles are preferably arranged distributed around the axis of rotation 60. Each individual receptacle 98 can be equipped with one or more magnets 100a, 100b (cf. FIG. 5).

Between the flange 96 and the housing base 12, a disk 102 is arranged so as to be rotatable about the shaft stub 90. This disk 102 is in particular directly driven. If the flange 96 is firmly coupled to the disk 102, the sleeve 92 is also rotated in accordance with the speed of the disk 102.

A slip drive for the sleeve 92 is formed by means of the disk 102 and the flange 96 which can be equipped with magnets 100. For this purpose, the disk 102 is made of a magnetically conductive material and in particular iron-containing material, so that the flange 96 can be magnetically coupled to the disk 102.

It can also be provided that a flexible element 104, for example a felt disc, is arranged between the disc 102 and the flange. Furthermore, a further flexible element 106, for example a thin band of steel, may be arranged on the flange 96, which is so flexible that it can adapt to the disk 102 and the flexible element 104 seated thereon, so as to achieve optimal power transmission from the flange 96 to the disk 102.

The magnets 100 can be permanent magnets or electromagnets. In the case of electromagnets, they can in particular be switched individually in order to implement an externally switched clutch whose slip can be controlled externally.

The force exerted on the disk 102 and thus the slip torque can be adjusted by fitting the receptacles 98 of the flange 96 with permanent magnets 100. If, for example, two magnets 100a, 100b can be positioned in a receptacle 98 (FIG. 5) and, as shown in FIG. 6, the flange has nine receptacles, then when using the same magnets 100, the forces can be measured in 18 steps and thus the slip moments in Set 18 levels. The slip torque or the torque which the sleeve 92 experiences can be adapted to the processing parameters by appropriate selection of the equipment, for example when the material of the carrier belt 16 and / or the material of the transfer belt 20 changes.

The disk 102 is driven at a speed which is higher than the speed desired for the sleeve 92, ie greater than the desired winding speed of the conveyor belt 20 on the conveyor belt winder 54. The coupling between the sleeve 92 and the driven disk 102 takes place via the magnetic forces of the magnet or magnets 100 on the Disc 102. With appropriate adjustment of this force, there is a relative movement between the sleeve 92 with its flange 96 to the disc 102 in order to obtain the desired speed of rotation of the sleeve 92; in this case there is slippage or slippage of the flange 96 with respect to the disk 102.

The slip drive consequently comprises a slip clutch.

In this way, axial bearing forces of the sleeve 92 on the stub shaft 90 can be minimized, so that the load on the housing base 12 is minimized even with larger transfer ribbon rolls. A self-aligning contact of the corresponding friction surfaces when the sleeve 92 rotates with respect to the disk 102 means that the driven rotation of the sleeve 92 is also stable in terms of friction torque, and high mechanical precision is not required because of the flexible adaptability.

The conveyor belt unwinder 52, which is not directly driven, is also provided with a slip clutch, as shown in FIG. 4. The conveyor belt unwinder 52 also has a shaft stub 108 which is connected to the housing base 12 in a rotationally fixed manner. A sleeve 110, which serves as a receptacle for a roll of the (unused) transfer belt 20, can be rotated around the shaft stub 108. The rotation of the sleeve 110 with respect to the stub shaft 108 is mediated via the transfer belt 20, indirectly driven by the transfer belt winder 54.

A disk 112 is connected to the shaft stub 108 in a rotationally fixed manner. On the sleeve 110 there is a disk-shaped flange 114, which is the Is facing disk 112 and, similar to that described above in connection with the flange 96, has a plurality of receptacles 116 for magnets 118. The disk 112 is made of a magnetically conductive material such as steel with a corresponding iron content, so that the disk 112 and the sleeve 110 can be coupled to one or more magnets 118 via the flange 114. The coupling strength in turn can be set by appropriately populating the receptacles 116. The receptacles are basically arranged as described with reference to FIG. 6 for the flange 96. The coupling strength is set in the same way.

The sleeve 110 can be fixed relative to the housing base 12 via the flange 114 with the non-positive coupling to the disk 112:

If the transfer ribbon winder 54 is stopped due to a corresponding air pulse or a corresponding sequence of air pulses, then there is basically the risk that the transfer ribbon will sag or become kinked and the like. Due to the provision of a slip clutch 120 in the case of the conveyor belt unwinder 52, which is not directly driven, these interfering effects can be avoided, since without (indirect) drive of the sleeve 110 via the conveyor belt winder 54, its rotation is immediately braked due to the slip clutch 120 and thus the transfer belt lifted printhead 24 is kept taut.

The axial axial forces are also minimized in this embodiment of the transfer belt unwinder 52. The printing device 10 according to the invention functions as follows:

When an information carrier 36 is printed on the transfer belt 20, the spring 84 presses the print head 24 in the direction of the pull-off element 40 via the print head holder 62, so that the print head 24 exerts a contact pressure on the transfer belt 20 and on the carrier belt 16. In this operating mode, the carrier tape 16 and the transfer tape 20 are guided past the print head 24 synchronously with essentially zero speed difference.

If a larger area that is not to be printed occurs, the control device sends a corresponding control signal to the passage valve 70 and the latter opens briefly, typical switching frequencies being 80 Hz or greater. As a result, an air pulse or an air pulse sequence is output to the pressure lines 72 and 88. As a result, the directly driven conveyor belt winder 54 is stopped at the same time via the brake 94 and the print head 24 is lifted off the transfer belt 20 via the element 74 which can be pressurized. This has the effect that a relative speed can form between the carrier tape 16 and the transfer tape 20 as it moves past the print head 24, with in particular no transfer of the transfer tape 20 relative to the print head 24 taking place.

Since the transfer belt is no longer transported by stopping the rotation of the transfer ribbon winder 54, this also stops the rotation of the sleeve 110 of the transfer ribbon winder 52. The transfer belt 20 is held taut via the slip clutch 120, since the sleeve 110 is conveyed without torque being applied (when the transfer belt 20 is transported) through the transfer belt 20 itself), the sleeve 110 is non-rotatably coupled to the disk 112 via the flange 114.

After the air pulse or the air pulse sequence has ended, the spring 84 causes the print head 24 to be reset in the direction of the carrier tape 16 in order to enable further printing of information carriers 36. During the resetting, the brake 94 is also released, so that the sleeve 92 can be transported further and the transfer belt 20 can in turn be transported through the printing device 10 essentially synchronously with the carrier belt 16.

Due to the slip drive for the transfer ribbon winder 54, a torque-stable drive for winding the (used) transfer ribbon is achieved.

Claims

1. Printing device for printing an information carrier (36) on a carrier tape (16), comprising a print head (24), a first transport device (14), by means of which the carrier tape (16) can be guided past the print head (24), and a second Transport device (18), by means of which a transfer ribbon (20) can be guided past the print head (24), which, when activated by the print head (24), prints an information carrier (36), the contact pressure of the print head (24) on the transfer ribbon (20) and the carrier tape (16) and the transfer ribbon feed can be controlled by the second transport device (18) in such a way that the carrier tape (16) can be guided past the print head (24) at a speed difference relative to the transfer tape (20) that the print head (24) can be lifted pneumatically from the transfer belt (20).

2. Printing device according to claim 1, characterized in that the print head (24) via a controllable air pulse or air pulse sequence from the transfer belt (20) can be lifted away.

3. Printing device according to claim 2, characterized in that the air pulse or the air pulse sequence is time-controllable.

4. Printing device according to one of the preceding claims, characterized in that the print head (24) for lifting away from the transfer belt (20) with a pressurizable movable element (74) is connected.

5. Printing device according to claim 4, characterized in that the pressurizable element is a membrane (74).

6. Printing device according to one of the preceding claims, characterized in that the print head (24) is pivotally arranged.

7. Printing device according to claim 6, characterized in that a pneumatic application surface on a print head holder (62) for moving the print head (24) between the print head (24) and a pivot axis (66) of the print head holder (62) is arranged.

8. Printing device according to one of the preceding claims, characterized in that the print head (24) is arranged biased with respect to a guide surface (42) for the carrier tape (16).

9. Printing device according to claim 8, characterized in that the biasing force acts against a lifting force for the print head (24) away from the guide surface (42).

10. Printing device according to one of the preceding claims, characterized in that a stop (78) for the print head (24) is provided for the movement of the transfer belt (20) away.

11. Printing device according to claim 10, characterized in that the stop (78) of a pneumatic loading surface of a print head holder (62) is arranged opposite.

12. Printing device according to one of the preceding claims, characterized in that a stop for the movement of the print head (24) on a guide surface (42) of the carrier tape (16) is provided.

13. Printing device according to claim 12, characterized in that the stop lies in the vicinity of the guide surface (42) or forms at least part of the guide surface (42).

14. Printing device according to one of claims 11 to 13, characterized in that a stop (78; 42) is provided with a damping element (80; 86).

15. Printing device according to one of the preceding claims, characterized in that a guide surface (42) for the carrier tape (16) is formed during printing on a pull-off element (40) for the carrier tape (16).

16. Printing device according to one of the preceding claims, characterized in that the movement of the print head (24) can be switched with a switching frequency of 80 Hz or faster.

17. Printing device according to one of the preceding claims, characterized in that the second transport device (18) comprises a transfer ribbon unwinder (52) and a transfer ribbon unwinder (54).

18. Printing device according to one of the preceding claims, characterized in that the transport of the transfer belt (20) by the second transport device (18) can be pneumatically stopped.

19. Printing device according to one of the preceding claims, characterized in that the second transport device (18) with the movement of the print head (24) can be synchronized.

20. Printing device according to one of the preceding claims, characterized in that an air pulse or an air pulse sequence for moving the print head (24) away from the transfer belt (20) simultaneously causes braking of the movement of the transfer belt (20).

21. A printing device according to claim 20, characterized in that the air pulse or the air pulse train actuates a brake (94) of a transfer ribbon unwinding device (52) and / or transfer ribbon winding device (54).

22. Printing device according to one of claims 17 to 21, characterized in that the transfer ribbon unwinder (52) is driven indirectly.

23. Printing device according to the preamble of claim 1 or one of the preceding claims, characterized in that a drive of the second transport device (18) for the movement of the transfer belt (20) is designed as a slip drive.

24. Printing device according to claim 23, characterized in that a transfer ribbon winder (54) and / or a transfer ribbon winder (52) is driven at overspeed.

25. Printing device according to claim 23 or 24, characterized in that the slip drive comprises a directly driven element (102) which is coupled to a transfer ribbon receptacle (92), the coupling being non-positive.

26. Printing device according to claim 25, characterized in that the driven element (102) and the transfer ribbon receptacle (92) are magnetically coupled.

27. Printing device according to claim 26, characterized in that the transfer ribbon receptacle (92) facing the driven element (102) has a plurality of receptacles (98) for magnets (100).

28. Printing device according to claim 27, characterized in that the slip torque is adjustable by fitting or connecting magnets (100) in the magnet receptacles (98).

29. Printing device according to one of claims 17 to 28, characterized in that the transfer ribbon winder (54) is driven directly or the transfer ribbon winder (54) and the transfer ribbon winder (52) are driven directly.

30. Printing device according to claim 29, characterized in that the not directly driven winder (52) comprises a slip clutch (120) through which a transfer ribbon receptacle (110) can be fixed in terms of rotation relative to a housing.

31. Printing device according to claim 30, characterized in that the fixation is non-positive.

32. Printing device according to claim 30 or 31, characterized in that the fixing takes place via magnetic forces.

33. Printing device according to one of claims 30 to 32, characterized in that the transfer ribbon receptacle (110) is provided with a plurality of magnetic receptacles (116).

34. Printing device according to claim 33, characterized in that the fixing force can be adjusted by fitting or connecting magnets (118) in the magnet receptacles (116).

35. Printing device according to one of claims 17 to 34, characterized in that for the transfer ribbon winder (54) and / or the transfer ribbon winder (52) a rotatably arranged shaft stub (90; 108) is provided, on which a sleeve ( 92; 110) for receiving the transfer belt (20) rotatably.

36. Method for printing on recording media on a carrier tape by means of a print head which activates a transfer tape, characterized in that the print head can be lifted pneumatically away from the transfer tape.

37. The method according to claim 36, characterized in that an air pulse or an air pulse sequence, which lifts the print head away from the transfer ribbon, stops the transport of the transfer ribbon.