EP0730974A2 - Apparatus and ribbon cartridge for thermal transfer printing - Google Patents

Abstract

The colour band (29) is formed for the identification of marks for control states, whereby the marks enable an authorisation of the colour band material in a control unit including a microprocessor and fixed storage device. At least one valid reference code is stored in the fixed storage device. At least one identification facility (35) is located on the colour band cassette to supply at least a first piece of information about the status of the colour band on the spool to the microprocessor of the control unit.

Description

The invention relates to an arrangement and an ink ribbon cassette for a thermal transfer printing process according to the type specified in the preamble of claim 1. Such thermal printing processes have long been widespread on the market as high-quality non-impact printing processes for a wide variety of applications. A preferred application is provided for a franking machine which works according to a thermal transfer printing method.

Ribbon and thermal print cartridges generally have a supply spool, a take-up spool and a plurality of deflection rollers for guiding the ribbon. To achieve consistent print quality, it is necessary to tighten the ribbon.

EP 189 268 B1 discloses a receiving device for ink ribbon cassettes. The side wall of the cassette has an opening through which a roller for engaging the ink ribbon can pass in order to receive the drive force from it or to transmit it to a friction roller which is coupled to an encoder disk. The ribbon speed corresponds approximately to that of the printed matter which is transported between the ribbon and the counterpressure device.

EP 504 594 A2 has already provided a meandering tape guide between the print head and the take-up spool in order to ensure that the take-up from forces that can be achieved by friction between the ink ribbon and paper is decoupled. Practice has shown, however, that the aforementioned meandering band guide can be omitted if the deflection rollers are replaced by non-rotatable deflection pins.

Thermal transfer printing processes are often used in applications in which (for whatever reason) the relatively expensive, light and heat sensitive thermal direct printing paper has to be dispensed with. The ribbons used here allow printing on plain paper, but their costs also go directly into the consumption costs of the impression. It has therefore already been proposed in DE 31 45 221 C2 that a relative speed between the ink ribbon and the recording medium (printed matter) is always maintained. The required ribbon length is thus reduced.

Up to 99.9% of all prints consist of non-closed ones Printing areas, since otherwise the information content would be = 0. For example, only about 15% of the available space is printed on franking imprints. 85% of the color of the ribbon remains unused.

In summary, it can be said that thermal printing technology has comparatively high consumption costs per printed area and is also not particularly environmentally friendly due to the high proportion of carrier material (in thermal transfer printing).

Known thermal transfer printing processes use the ribbon only once. Color residues remain in the unused areas in each printing cycle. Since these unused areas can no longer be used for the subsequent printing cycle, an unnecessarily large amount of unwound ink ribbon is used up.

From US 4590 486 it is also known to stop the ink ribbon when there are spaces in the printed image in order to save expensive ink ribbon.

The efforts of the well-known manufacturers are now also concentrating on a reusable ink ribbon, in which only a part of the total ink available is melted out by each printing process. By running this ribbon several times (similar to the well-known typewriter ribbon), the ink supply is also exhausted after about 10 prints and the ribbon is used up.

A thermal transfer printing process is known from DE 37 21 925 C2, in which multiple use of the ink ribbon is possible without impairing the print quality. After the excitation of the printing elements, an ink layer half is melted off the ink ribbon, an ink layer half remaining on the ink ribbon under the melted ink layer halves, if that Ribbon is separated from the recording medium in a predetermined time interval after the excitation of the printing element, in which the ink layer half still has a relatively low viscosity in the melted state.

However, it has not yet been possible to produce one of these so-called multi-use tapes with (almost) constant print quality from the first to the last print. Rather, there is a considerable loss of contrast between the first and the second belt pass, which is in the range of approximately 50%. The areas on the ribbon that are used several times are immediately adjacent to areas that are used only once and therefore provide a higher contrast. This is not acceptable for many applications that demand consistently high print quality. This is also the reason why these so-called multi-use tapes have so far not been widely used on the market.

Means for a thermal transfer printing process have already been proposed in JP 62-288977 in order to regenerate a multi-use ink ribbon after a single use. The multi-use ink ribbon is wider than the print head and has a high-density ink region running over the aforementioned print head and a less dense ink region which runs at the level of the aforementioned print head. From this less dense ink region, ink is melted onto a recording medium when the aforementioned print head is activated. This consumption of ink can be replaced at a downstream point of the printing arrangement, and when heated by a second printhead, ink melted from the high-density ink region runs into the less dense ink region by gravity and capillary action. After that, a roller is arranged on the take-up reel, around the Smooth the belt surface. Such an arrangement is essentially intended for typewriters, ie line printers. Such center arrangements are unsuitable for franking machines simply because a printing column is printed which extends over the entire ribbon width. Even if the ribbon would be widened to twice its width, which would make it considerably more expensive, the capillary effect would not be supported by gravity if the letter, which was usually transported lying down, was moved with the ribbon under the print head. The ink then melted off by a second printhead will only drip onto the letter.

From the document JP 63-328237, heated rollers for a thermal transfer printing process have become known in order to regenerate a multi-use ink ribbon after a single use. For this purpose, however, the roller must be arranged above the multi-use ink ribbon so that the paint does not run past the roller or onto the halogen lamp used for heating, which would destroy the latter. This arrangement makes such means unsuitable for franking machines because it would be difficult to construct a corresponding cassette which brings the heated roller into contact with the ink ribbon at a location downstream of the print head.

It is already known to use a second printhead to prevent the use of a color band once used for fraud attempts (DE 38 00 137 A1). The franking print image should no longer be readable on the take-up reel, which is why the color which is not required before printing is printed by the second print head in the form of a negative impression on the ribbon part which has already passed the first print head. This means that ribbon regeneration is not possible.

Furthermore, it is already known from US 4,924,240 in the meantime, when no print material is being transported under the print head, in contrast to the printing position, to take a distance from the print material and to wind the ribbon back a length, so that each ribbon section can be used for a time, ie several times. However, it is disadvantageous that an electromechanical actuator for leaving the printing position and an additional motor for rewinding the ribbon are required, which have to be actuated relatively often. This means that high printing speeds cannot be achieved.

DE 42 25 798 A1 has already proposed an economical termotransfer printing process which works with a lower ribbon speed of the ink ribbon than the transport speed of the recording medium (saving mode). The process boils down to optimal use of the ink residues between the printing columns. The motor that is required for the rewinding of the ribbon and the drive motor for the unwinding of the ribbon are controlled by a complicated process and loaded differently, so that the life is reduced and the maximum printing speed is not reached.

From US 5,344,244 a thermal inkjet is known which can determine the sections of an ink ribbon that can still be used by means of a sensor and microprocessor. Due to the generation of color images by three primary colors, which can be printed on top of each other, there is a different consumption of the respective color sections on the tape. There are always unused sections of color on the ribbon and such ribbons with alternating sections of color are very expensive. Using a second printhead, the consumption of color sections can now be recorded on the tape. If the tape is used again, the microprocessor uses these markings to determine whether printing is still possible.

A real multiple use of each color section on the tape is not possible.

From EP 550 227 A2 a multi-use ribbon control is known which works with a magnetic marking on the ribbon. Such marks are difficult to manufacture because they cause the color to melt, i.e. must withstand high temperatures. Therefore such markings are only possible at the beginning or end of the tape in order to be able to detect a cassette change by means of a Hall effect sensor. The determined orientation of the magnetization can thus be used to determine how the cassette was inserted. If the cassette was inserted the other way round, the orientation of the magnetization is opposite.

Another disadvantage of all the above solutions is that they do not provide protection against imitations, which are known as so-called piracy products and are offered cheaper. Little emphasis is placed on print quality, which is a requirement for certain applications. It has already happened that the original cassettes are not refilled by the manufacturer but by third parties with cheap tape material of poor quality. Particularly in the case of multi-use ink ribbon cassettes, there is a noticeable deterioration, which leads to illegible imprints, which the postal authorities cannot accept, for example, for franking imprints.

An arrangement with an associated method should be found which avoids the disadvantages of the prior art and enables the wide use of color ribbons for thermal transfer printing devices with consistently good print quality. In particular, the printing of a printing column over the entire width of the ink ribbon should be made possible on a recording medium.

Furthermore, a multi-use ribbon cassette that could be reversed by hand should be created, which also enables a consistently good print quality under the harsh conditions of multi-use operation.

These objects are achieved with the features of claims 1 and 10.

The arrangement for a thermal transfer printing method with a thermal print head which has a multiplicity of printing elements is connected to a microprocessor in a control unit via power electronics and via pressure control. A counter-pressure device (not shown in the figures) presses the recording medium against an ink ribbon which is wound up from a first spool onto a second spool and is supported against the thermal print head. A roller is preferably used as the counterpressure device and a microprocessor control is used, as was described in detail in US Pat. No. 4,746,234 "Relating to postal franking machines".

According to the invention, it is provided that the ink ribbon is designed to recognize markings for control states, the ink marking authorizing the ink ribbon material in the control unit comprising a microprocessor and non-volatile memory that at least one valid reference code is stored in the aforementioned non-volatile memory, that at least a first detection means is arranged on the ink ribbon cassette, which supplies at least first information about the status of the ink ribbon on the associated supply reel, including at least the validity of the ink ribbon material or the type of ink ribbon, to the microprocessor of the control unit before the ribbon end is reached and that the microprocessor to compare the stored reference codes with the detected status information and, if they match, are programmed to authorize the ink ribbon, printing being prevented if they do not match. The codes can be modified using the microprocessor.

The invention can be used advantageously if the ink ribbon is a multi-use ink ribbon with an optically readable ink ribbon marking applied by the manufacturer.

It is provided that the multi-use ink ribbon is provided with a readable code, preferably a bar code, which is recognized by the microprocessor after a period of time or periodically, in order to identify control states regarding the wear of the ink ribbon and the validity of the ink ribbon.

The first detection means is preferably an optical detection means which provides information about the validity of the ink ribbon for printing and / or about the amount of ink ribbon remaining on the assigned reel before the ink ribbon end is reached and that the ink ribbon is provided with an applied marking, which is readable by the detection means.

The thermal print head acts on the ink ribbon arranged in a cassette with a predetermined print pattern in order to produce a marking which is detected by the first optical detection means.

After the print head, heat-emitting means are arranged near the deflection roller at the window of the cassette and the microprocessor of the control is programmed to control the heat-emitting means so that they contribute to the formation of a marking.

It is provided that the heat emitting agent a tube lamp suitable for increased heat emission, which melts the top layer in columns, and includes a downstream roller, by means of which the ribbon is ironed smooth and the color is distributed approximately evenly when a franking imprint is applied and which are given away from the ribbon when a mark is printed becomes.

The heat-emitting means can comprise a second counter-pressure roller or receptor roller and a second print head arranged at a relatively short distance from the first print head and oriented in the tape transport direction. In order to generate a negative impression on the second counterpressure roller or receptor roller, the microprocessor calculates a time delay in the activation of the second print head in accordance with the distance.

A thermal printhead, which has a large number of printing elements and is connected to a control unit via power electronics and a pressure control, acts on a print material with a predetermined printing energy via a ribbon as a printing medium.

Based on the fact that the contrast generated in thermal transfer printing is directly dependent on the printing energy used, printing energy control of the thermal transfer printing is carried out according to the invention, depending on the quality of the existing multi-use ink ribbon. The amount of ink in the multi-use ribbon depends linearly on the number of uses.

First optical or mechanical detection means are arranged on the printing medium, which provide information about the amount of ribbon remaining on the assigned spool before the ribbon end is reached. The end of the ribbon is recognized, for example, by the fact that a second optical identification mark is detected or the encoder disc stops rotating or the number of prints is counted by the processor. The information is transmitted to the control unit.

According to the invention, the pressure medium housing comprises at least one electronic, magnetic, optical and / or mechanical storage medium. Stored information concerns the multi-use status (MUS). This shows how often this corresponding ribbon direction has already been used. Another stored information Ribbon Movement Direction (RMD) relates to the current arrangement state of the pressure medium housing, i.e. the direction of movement of the ribbon, i.e. Cartridge inserted or not turned.

A second detection means can alternatively be a mechanical detection means which supplies information about the amount of ribbon remaining on the associated spool, which information is stored in a mechanical memory of the cassette, before the ribbon end is reached. Reaching the ribbon end causes a change in the information state of the storage medium of the pressure medium housing, which is scanned after removal and reinsertion into the old or new turned position of the pressure medium housing in order to read the information and transmit it to the control unit. Detection means arranged in the machine engage on the pressure medium housing and provide information about the direction of belt movement. This information is transmitted to the control unit.

• Eingeben einer Referenzinformation in nichtflüchtige Speichermittel der Steuerung,
• Bandvorschub nach dem Einsetzen der Kassette und Scannen des Farbbandes,
• Gewinnen einer entsprechenden Information am Anfang des Farbbandes aus einer aufgebrachten Markierung und Vergleich mit vorgenannter Referenzinformation,
• Signalisieren des Farbbandtypes bzw. der Gültigkeit nach dem Einsetzen und Inbetriebnahme der Kassette über eine Anzeige,
• Steuerung der Druckenergie entsprechend der Gültigkeit bzw. Sperren der Druckenergie bei Ungültigkeit der aufgebrachten Markierung,
• Bandvorschub bis zum Farbbandende entsprechend der getätigten Aufdrucke und
• Ermitteln des nahenden Bandendes und/oder Gewinnen einer entsprechenden Information aus einer Markierung des Farbbandes, bevor das Farbband verbraucht ist.

For an associated thermal transfer printing method with a thermal print head, which has a multiplicity of printing elements and is connected to a microprocessor and storage means of a controller via power electronics and via a pressure controller Counter pressure device and an ink ribbon cassette, the ink ribbon being wound from a first spool onto a second spool, are controlled by the microprocessor in the following steps:

• Entering reference information into non-volatile memory means of the control
• Tape feed after inserting the cassette and scanning the ribbon,
• Obtaining corresponding information at the beginning of the ink ribbon from an applied marking and comparison with the aforementioned reference information,
• Signaling the type of ribbon or the validity after inserting and commissioning the cassette via a display,
• Control of the pressure energy according to the validity or blocking of the pressure energy if the applied marking is invalid,
• Ribbon feed up to the end of the ribbon according to the prints made and
• Determining the approaching end of the ribbon and / or obtaining corresponding information from a marking on the ribbon before the ribbon is used up.

The thermal transfer printing process differs in an inventive manner from the known technical solutions in that the code for the aforementioned corresponding information is changed periodically or at intervals.

• Erkennen des nahenden Bandendes,
• Eingeben einer entsprechenden Information über die Abnutzung des Farbbandes nach dem letzten Abdruck in ein dem Farbband beigefügtes Speichermittel oder Einspeicherung in das Farbband in Form einer Markierung,
• Bandvorschub bis zum Farbbandende,
• Signalisieren des Farbbandendes zwecks Herausnehmen und Wenden der Kassette,
• Wenden und Einsetzen der Kassette und Scannen des Speichermittels bzw. Farbbandes bei Bandvorschub,
• Erkennen des Vorbenutzungsgrades,
• Steuerung der Druckenergie entsprechend des aktuellen Vorbenutzungsgrades.

An advantageous solution for the multi-use operation of an ink ribbon is controlled by the microprocessor in the following steps:

• Recognizing the approaching end of the band,
• Entering appropriate information about the wear of the ink ribbon after the last print in a storage medium attached to the ink ribbon or storing it in the ink ribbon in the form of a marking,
• Ribbon feed to the end of the ribbon,
• Signal the end of the ribbon for removal and flipping the cassette,
• Turning and inserting the cassette and scanning the storage medium or ink ribbon when feeding the ribbon,
• Recognizing the degree of prior use,
• Control of the pressure energy according to the current degree of pre-use.

Figur 1a,

Anordnung einer Farbbandkassette in einer Thermotransferdruckeinrichtung,

Figur 1b bis 1d,

weitere Varianten mit Multi-Use-Farbbandkassetten,

Figur 2,

Speichermittel für eine Multi-Use-Farbband kassette,

Figur 3a,

Anordnung der Multi-Use-Farbbandkassette in Vorderansicht

Figur 3b,

Anordnung der Multi-Use-Farbbandkassette in Rückansicht

Advantageous developments of the invention are characterized in the subclaims or are shown in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. Show it:

Figure 1a,

Arrangement of an ink ribbon cassette in a thermal transfer printing device,

1b to 1d,

further variants with multi-use ribbon cartridges,

Figure 2,

Storage means for a multi-use ribbon cassette,

Figure 3a,

Front view of the multi-use ribbon cartridge

Figure 3b,

Rear view of the multi-use ribbon cartridge

In a thermal printing device, for example, a thermal transfer or ETR print head 1 with an associated — not shown — pressure controller 14 and with an associated power electronics can be used. The aforementioned components of the thermal transfer printer are usually controlled by an intelligent control means, for example by a control unit (not shown) which has a microprocessor .mu.P. The ink ribbon 29 is unwound from a spool 26 and wound onto a spool 25. Here the ink ribbon runs from the spool 26 between the print head 1 and the recording medium 2 to the spool 25. The recording medium 2 is pressed onto the ink ribbon 29 in the usual way by means of a counter-pressure roller (not shown). Such an arrangement has already been proposed in US 4,746,234.

The arrangement and ribbon cassette for a thermal transfer printing method according to the invention - shown in FIG. 1 a - uses only the ribbon 29 as a storage medium for information. A first piece of information relates to piracy protection and is applied at least at the beginning of each ink ribbon 29 of a cassette protected in this way during its manufacture. Such information is applied as a printed marking, for example in the form of a bar code, and can be scanned by a first recognition means 35 when the cassette is newly inserted, which is arranged after the unwinding roller 26 in front of the first print head 1 opposite the ink ribbon 29. The detection means 35 signals the microprocessor at least the type of the ribbon.

A reflex light barrier or a commercially available scanner can be used as the first detection means 35 in order to read the bar code. Such a printed marking can be applied to the tape at regular intervals. If the ribbon has now run through for the first time, at the end of the ribbon 29, ribbon end information is supplied to the microprocessor by the first detection means 35 arranged in the vicinity of a first window 21a with the first deflection roller 31a. With the remaining amount of ink ribbon wound up, a final print is possible before replacing the cassette.

The aforementioned detected bar code is compared with a reference code stored in a non-volatile manner in a memory of the microprocessor control. A Such a reference code can be supplied, for example, from a remote data center to the microprocessor controller and authorize the manufacturer's color ribbons with the same bar code for printing for a predetermined period of time (period). Otherwise the thermal transfer printing device, for example a franking machine, is blocked. This also prevents the manufacturer from using outdated ribbons that would only contribute to poorer print quality. Two or more codes can also be validly recognized for a transitional period. For this purpose, it is necessary to store several reference codes, each of which is valid for a different or overlapping time period, in a non-volatile manner.

In the preferred second variant, a multi-use ribbon cassette is used. In this case, a multi-use ink ribbon is then used as a storage medium for the aforementioned first information for protection against piracy and for a second information relating to the multi-use status.

FIG. 1d shows the arrangement of such a multi-use ribbon cassette in a thermal transfer printing device. The ink ribbon 29 is unwound from a spool 26 and wound onto a spool 25. The ink ribbon runs from the reel 26 over the roller 31a, then between the printhead 1 and the recording medium 2, then over a second printhead 70 and then over the roller 31b to the reel 25. The recording medium 2 is made by means of a counter-pressure roller (not shown) pressed onto the ribbon 29. From the first marking, the number of impressions is detected by the microprocessor using an encoder 51. The approach of the ribbon end can thus also be detected. In addition, printed tape end information can be supplied from the detection means 35 to the microprocessor.

After a predetermined number of impressions, the microprocessor uses the first print head 1 to apply at least one further marking, for example in the form of a bar code. This further marking includes at least the aforementioned first information on protection against piracy. In addition, the aforementioned marking can include second information relating to the multi-use status, or a further marking can also be applied which contains the second information relating to the multi-use status.

After the predetermined number of impressions, the predetermined number being selected so that only a little ink ribbon remains on the unwinding reel of the cassette, the microprocessor uses the first print head 1 to set a mark, which is further deepened by means of the second print head 70. The second print head 70 is actuated by the microprocessor in a time-delayed manner relative to the first print head 1. A corresponding control method has already been carried out in DE 42 27 596 A1 and has only been modified with regard to the larger distance between the two print heads.

The end of the ribbon can also be detected by the microprocessor via an encoder 51 in that the encoder disc 50 does not continue to rotate. The ribbon end is signaled by the microprocessor using a beeper. The display now shows that the cassette must be changed. A multi-use ribbon cartridge is rotated after removal and then reinserted.

According to the invention, in this second variant, a marking has now been applied to the ink ribbon at the ink ribbon end, which is so far removed from the ink ribbon end that an imprint can just be carried out. The first print head 1 is used to generate a such marking driven by the microprocessor via power electronics with energy. The ink melts off the ribbon and drips onto the counter pressure roller. The material of the counter pressure roller does not accept the ink drop, but repels it. In addition, a scraper can be arranged on the counterpressure roller (not shown). A bar code can advantageously be used as the printed marking, which is deepened by the second print head 70 in a time-shifted manner relative to the first print head 1. The ink continues to melt from the ink ribbon 29 and drips onto a counter pressure roller 80. The material of the counter pressure roller 80 does not accept the ink drop, but repels it. In addition, a scraper 81 can be arranged on the ink collecting container 82 of the counterpressure roller 80.

After the above impression has been carried out, the ribbon runs in a controlled manner from the microprocessor to the end of the ribbon. The recording medium 2 is transported away from the print head 1. The marking runs up to the second deflection roller 31b before the ink ribbon is stopped.

When the ribbon has run through for the first time, the cassette is turned over. The ink ribbon 29 is then unwound from a spool 25 and wound onto the spool 26. The marking can then be made after the change, i.e. are scanned by the first detection means 35 when the cassette is turned. At the beginning of each new pass of the ink ribbon 29, information from a first detection means 35 arranged in the vicinity of a first window 21b with the second deflecting roller 31b (or window 21a and deflecting roller 31a when the cassette is turned again) is delivered to the microprocessor.

The invention enables the code for the first or second information to be changed. A change of code for the first information when changing the Multi-use ribbon cartridge improves piracy protection. Of course, the changed code must be stored in a non-volatile memory in a memory of the microprocessor control as a reference code. It is therefore necessary to change the code for the second information when changing the multi-use ink ribbon cassette if the wear of the multi-use ink ribbon is to be recognized on the basis of the number of changes carried out.

Each time the multi-use ribbon cartridge is turned, the printhead is loaded with the required or a special print pattern. With approx. 15% to 20% space usage per print and up to five layers on the ink ribbon, only a small proportion of the color is used per print. It is possible to support the distribution of the color of the top layer from unused or less used areas to the more used areas by suitable means 70, 80, 90. The means 70 is the second thermal transfer print head 70 suitable for the increased delivery of a heat pattern, which melts the top layer. The ribbon is ironed smoothly by a downstream roller 90 and the color is distributed approximately uniformly. It is also possible to heat the roller 90 in a manner not shown.

A second thermal transfer print head 70 is therefore located in the printing device, which is identical in construction to the first thermal transfer print head 1 and is mechanically arranged downstream of it in the printing direction. This second thermal transfer print head 70 is fed with the inverse print data of the previous print in a defined time delay, so that it still detaches the color particles from the ink ribbon that were left out in the original print. A delay in the activation is calculated by the microprocessor and a corresponding activation method can in principle be carried out as already described in DE 42 27 596 A1 was executed. In contrast to DE 42 27 596 A1, the alignment of the two print heads along the tape transport direction is the same and the distance between the print heads is greater.

This "negative impression" takes place again on a rotating receptor roller 80, which is cleaned by a mechanical scraper 81 from unnecessary color particles with each revolution. These superfluous paint particles are collected in a collecting container 82 and can (possibly) be recycled as paint material.

This ensures that the entire ribbon covering is in a defined, uniform quality after each pass and that the method described above for controlling the printing energy can be used.

The expenditure required for the solution according to the invention (second print head, receptor roller, detection) is only used once in each printing device, while a considerable cost saving is achieved with each print by using the multi-use ink ribbon. This guarantees a quick amortization of the one-time expenses.

In order to ensure a perfect detection of the quality of the ribbon present during the printing process, the ribbon is provided with a marking which makes it possible to optically detect the ribbon use and accordingly to automatically control the associated printing energy by means of an actuator so that each time the ribbon is used about the same amount of ink are melted with the same print samples. Of course, other types of marking and detection are also conceivable, such as magnetic, mechanical or chemical for marking the use.

This ensures that with increasing "Wear" of the ribbon (ie with a decreasing amount of ink) a correspondingly increasing printing energy is used, which leads to the fact that the amount of ink released per printing process remains almost constant and thus a consistently good impression quality is guaranteed.

Furthermore, the ribbon quality detection can also be used to determine a maximum number of ribbon runs, which must not be exceeded, in order to ensure a minimum required print quality. Is the maximum z. B. reached with 5 passes, the impression (after detection) is refused by the control means with an error message.

Thermal transfer printers are usually controlled by an intelligent control means (such as microprocessors). This existing control means is now used according to the invention to be able to use the method described above to ensure a constant print quality when the ribbon is run through several times, even in the case of non-closed printing surfaces (of which 99.9% of all prints consist, since otherwise the information content would be = 0).

In another variant - shown in FIG. 1 a - an expensive second thermal transfer print head 70 is replaced in a suitable manner by a heat-emitting means 60, 90. The heat-emitting means 60, which supports the distribution of the color of the top layer from unused or less used areas to the more used areas of the multi-use ink ribbon 29, is switched off in a further variant by the microprocessor of the control and / or by means of a Suitable lever device pivoted away when a distribution of the color of the top layer is undesirable. This is the case if one with the first thermal transfer print head 1 in the aforementioned manner Marking is applied with flexible coding, which should still be detectable after turning the cassette. The microprocessor of the control is thus programmed to control the heat-emitting means 60, 90 in such a way that they contribute to the formation of a marking.

FIG. 1b shows the basic structure of a multi-use ribbon cassette with an alternative storage means arranged in the cassette housing. A thermal transfer or ETR print head 1 with associated — not shown — pressure controller 14 and power electronics and microprocessor controller can be used as the thermal printing device, for example. The ink ribbon 29 is unwound, for example, from a spool 26 (or 25) and wound onto a spool 25 (or 26). The ink ribbon runs from the spool 26 (or 25) over the roller 31a (or 31b) and between the print head 1 and the recording medium 2 through the rollers 31b (or 31a) to the spool 25 (or 26). The recording medium 2 is pressed onto the ink ribbon 29 by means of a counterpressure roller (not shown).

In this further variant, which is shown in FIG. 1b, the multi-use ink ribbon cassette 20 has a storage means 24 and an expensive second thermal transfer print head 70 is replaced in a suitable manner by a heat-emitting means 60, 90. In this combined variant with a marking printed by the manufacturer for a first piece of information regarding piracy protection on the multi-use ink ribbon 29 and a mechanical storage of the second information in the cassette but not on the tape, it is still possible to distribute the color of the Support top layer from unused or less used areas to the more used areas by other suitable means 60, 90. The means 60 is for increased heat emission suitable festoon lamp, which melts the top layer. The ribbon is ironed smoothly by a downstream roller 90 and the color is distributed approximately uniformly. It is also possible to heat the roll 90.

Before the cassette is turned, information about the multi-use status is stored in the storage means 24. The multi-use status (MUS) shows how often this corresponding ribbon direction has already been used.

The storage means 24 is preferably designed as a mechanical storage means. However, the storage means 24 can also be an optical, magnetic or electronic storage means of the cassette.

The storage means 24, which is designed, for example, as a coding disk, makes it possible to remove the cassette at any time without loss of MUS information, and display means 28 are provided. The display means indicate to the operator through a window 27 if the cassette is incorrectly reinserted after it has been removed in the meantime. The display means can have recesses and elevations which prevent inadvertent incorrect insertion or, after turning the cassette, its insertion as long as the ribbon has not yet been completely unwound to the end. For example, a mandrel or a mechanical detector 410, which triggers an acoustic or optical signal, can engage in the recesses (FIGS. 2 and 3a).

In addition, locking means 34 are provided, which assume a new locking position each time they are removed. The locking means can, for example, have a flat shape (not shown), a nipple for locking and an axis between which and the cassette housing the encoder disk 24 is rotatably clamped.

1c shows a further variant for a multi-use ribbon cassette. Further spring-mounted deflection rollers are arranged in this cassette. The ink ribbon runs from the reel 26 (or 25) via rollers 31a and 32a (or 31b and 32b) and between the print head 1 and the recording medium 2 through the rollers 31b and 32b (or 31a and 32a) to the reel 25 (or 26). The recording medium 2 is pressed onto the ink ribbon 29 by means of a counterpressure roller (not shown).

The resiliently mounted deflection rollers 32a and 32b run in slots 22a and 22b of the cassette housing 20, shown in FIG. 3a. The first mechanical detection means 420 is arranged in the cassette compartment on the rear so that the correctly inserted cassette with the deflection roller ends 32a and 32b comes into contact with the first mechanical detection means 420.

FIG. 2 shows a mechanical storage device for a multi-use ribbon cassette. The mechanical storage means 24 is again designed as a coding sheath for storing MUS and RMD information.

• a) Die Codierung für den Benutzungsgrad 24a inkrementiert;
• b) Die Seitenanzeige der Kassette 24, 28b geändert;
• c) Die Codierung 28b zum richtigen Einlegen der Kassette weitergeschaltet;
• d) Die Selbsthaltung der Rastklinke wird aufgehoben.

When the ribbon end is reached, a locking pawl is lowered into an opening 19 as a self-holding actuating means above the setting collar. When the cassette is removed, the coding disk is rotated by a locking position (not shown). This will:

• a) The coding for the degree of use 24a is incremented;
• b) The side display of the cassette 24, 28b changed;
• c) the code 28b advanced to insert the cassette correctly;
• d) The latch is released.

The cassette can now only be used rotated in the machine so that the tape runs back. If the cassette is removed in the meantime, the state of the cylindrical coding disk 24 does not change.

FIG. 3a shows an arrangement of the multi-use ink ribbon cassette according to the basic diagram in FIG. 1c in a cassette compartment in a front view.

It is provided that a storage means 24 for storing a multi-use status (MUS) and / or a Ribbon Movement Direction (RMD) information is provided, that windows 23a, 23b for scanning the storage means 24 are arranged in the cassette housing are that windows 21a, 21b for scanning the ink ribbon and or for engaging for displacement with an encoder 51 by means of a friction wheel 50 or for engaging heat-emitting means 60, 70, 80, 90 are arranged in the cassette housing, that the windows 21a or 21b in are arranged in the vicinity of the deflection rollers 31a or 31b and that slots or windows 22a, 22b for further deflection rollers 32a, 32b are arranged, on which the first detection means 420 is arranged, which provides information about the amount of ribbon remaining on the associated reel before the Ribbon end is reached, and that the deflection rollers 32a, 32b are resiliently mounted.

After detection of the approaching end of the tape, a switch (S) 403 is actuated by the micro-processor, which closes a circuit via voltage source 405, magnet coil 402, a switch arranged in parallel consisting of core contact 406 and armature contact 407 being closed. Now, even if the switch (S) is opened, the circuit remains (self-holding). The magnet, consisting of magnetic coil 402 and iron core 406, is provided, one on Pivot 404 lever 407, 401 to operate. The lever 401 engages with the recess 19 in the storage means 24 with its actuating means 40. This causes corresponding information to be entered when the multi-use ribbon cassette is removed.

After the cassette has been reinserted, the detection means 409 optically or mechanically scans the information from the storage means 24.

FIG. 3b shows the arrangement of the multi-use ribbon cassette in a rear view. Another detection means 420 is in engagement with one end of the deflection roller 32b. When the ribbon end is reached, the ribbon is tensioned against the spring action of the spring 33b and thus the detection is preferably made possible by a microswitch.

The invention is not limited to the present embodiment. Rather, a number of variants are conceivable which make use of the solution shown, even in the case of fundamentally different types.

Claims (15)

Arrangement for a thermal transfer printing method with a thermal print head, which has a multiplicity of printing elements and is connected via a power electronics and via a pressure controller to a microprocessor in a control unit, a counterpressure device and an ink ribbon which is wound from a first spool onto a second spool,
characterized by - That the ink ribbon (29) is designed to recognize markings for control states, the marking enabling authorization of the ink ribbon material in the control unit comprising a microprocessor and non-volatile memory, that at least one valid reference code is stored in the aforementioned non-volatile memory, - That at least a first detection means (35) is arranged on the ribbon cassette, which provides at least first information about the status of the ribbon on the associated supply spool, including at least the validity of the ribbon material or the type of ribbon, to the microprocessor of the control unit before the ribbon end is reached as well - That the microprocessor is programmed to compare the stored reference code with the detected status information and, if there is a match, for authorization of the ink ribbon, printing being prevented in the event of a mismatch. Arrangement according to claim 1, characterized in - That the thermal print head (1) acts on the ribbon (29) arranged in a cassette with a predetermined print pattern to produce a mark which is detected by the first optical detection means (35), and - That after the printhead (1) at the window (21a or 21b) in the vicinity of the deflection roller 31a or (31b) heat-emitting means (60 or 70, 80, 90) are arranged, the microprocessor of the control being programmed, the heat -Delivering means (60) or (70) so that they contribute to the formation of a label. Arrangement according to claims 1 and 2, characterized in that the heat-emitting means comprises a tubular lamp (60) suitable for increased heat dissipation, which melts the top layer in columns, and a downstream roller (90) by means of which the ribbon is ironed smooth and the Color is distributed approximately evenly when a franking imprint is applied and which are given away from the ink ribbon when a marking is printed. Arrangement according to claims 1 to 3, characterized in that the heat-emitting means comprises a second counter-pressure roller (80) or receptor roller and a second printhead (70) which is arranged at a relatively short distance from the printhead (1) and is oriented in the direction of ribbon transport, and that Generation of a negative impression on the second counter-pressure roller (80) or receptor roller, the microprocessor calculates a time delay in the activation of the second print head (70) according to the distance. Arrangement according to one of Claims 1 to 4, characterized in that the first detection means is an optical detection means (35) which provides information about the validity of the ink ribbon for printing and about the ink ribbon remaining quantity on the assigned spool before the ink ribbon The end is reached and that the ink ribbon is provided with an applied marking which can be read by the detection means (35). Arrangement according to one of claims 1 to 4, characterized in that the ink ribbon is a multi-use ink ribbon with an optically readable marking applied by the manufacturer. Arrangement according to one of Claims 1 to 6, characterized in that, in order to identify control states relating to the wear of the ink ribbon and the validity of the ink ribbon, the multi-use ink ribbon (29) is provided with a readable code which is sent by the microprocessor after the time has elapsed or changed periodically. Arrangement according to claim 1, characterized in that a second detection means is a mechanical detection means (420) which provides information about the amount of ribbon remaining on the associated reel stored in a mechanical memory (27) of the cassette before the ribbon end is reached . Arrangement according to one of claims 1 to 8, characterized in that the power electronics contain means controlled by the microprocessor in order to control the energy supplied to the print head according to the degree of use of the multi-use ink ribbon. A thermal transfer printing method using a thermal print head having a plurality of printing elements and is connected via power electronics and print control with a microprocessor and memory means of a controller, a counter-pressure device and an ink ribbon, wherein the ribbon is wound from a first spool onto a second spool, characterized , by the control by the microprocessor in the following steps: Input of reference information into non-volatile memory means of the control, - tape feed after inserting the cassette and scanning the ribbon, Obtaining corresponding information at the beginning of the ink ribbon from an applied marking and comparison with the aforementioned reference information, - signaling the type of ribbon or the validity after inserting and starting up the cassette via a display, - control of the pressure energy according to the validity or blocking of the pressure energy if the applied marking is invalid, - Ribbon feed up to the end of the ribbon in accordance with the prints made and - Determining the approaching end of the ribbon and / or obtaining corresponding information from a marking on the ribbon before the ribbon is used up. Thermal transfer printing method, according to claim 10, characterized by the periodically or at intervals changing the code for the aforementioned corresponding information. Thermal transfer printing method with a thermal print head, which has a multiplicity of printing elements and is connected via power electronics and via a pressure controller to a microprocessor and storage means of a controller, a counterpressure device and a multi-use ink ribbon, the multi-use ink ribbon from a first spool is wound on a second spool, characterized by the control by the microprocessor in the following steps: - recognizing the approaching end of the band, Entering appropriate information about the wear of the ink ribbon after the last print in a storage medium attached to the ink ribbon or storing it in the ink ribbon in the form of a marking, - ribbon feed to the end of the ribbon, - signaling the end of the ribbon in order to remove and turn the cassette, - turning and inserting the cassette and scanning the storage medium or ink ribbon when feeding the ribbon, - recognition of the degree of prior use, - Control of the pressure energy according to the current degree of prior use. Multi-use ink ribbon cassette, the multi-use ink ribbon being wound up from a first spool onto a second spool, characterized in that windows (21a, 21b) for scanning the ink ribbon and or for engaging it to be taken up by an encoder (51) by means of a friction wheel (50) or for engaging heat-emitting means (60, 70, 80, 90) are arranged in the cassette housing such that the windows (21a or 21b) are arranged in the vicinity of the deflection rollers (31a) or (31b). Multi-use ribbon cassette, the multi-use ribbon being wound up from a first spool onto a second spool, characterized in that a storage means (24) for storing a multi-use status (MUS) - and / or a ribbon -Movement-Direction (RMD) -Information is provided that windows (23a, 23b) for scanning the storage medium (24) are arranged in the cassette housing, that windows (21a, 21b) for scanning the ribbon and or for engaging to take away with a Encoders (51) are arranged in the cassette housing by means of a friction wheel (50) or heat-emitting means (60, 70, 80, 90) so that the windows (21a or 21b) are located in the vicinity of the deflecting rollers (31a) or (31b). are arranged. Multi-use ribbon cassette, the multi-use ribbon being wound up from a first spool onto a second spool, characterized in that a storage means (24) for storing a multi-use status (MUS) - and / or a ribbon -Movement-Direction (RMD) -Information is provided that windows (23a, 23b) for scanning the storage medium (24) are arranged in the cassette housing, that windows (21a, 21b) for scanning the ribbon and or for engaging to take away with a Encoders (51) are arranged in the cassette housing by means of a friction wheel (50) or heat-emitting means (60, 70, 80, 90) so that the windows (21a or 21b) are located in the vicinity of the deflecting rollers (31a) or (31b). are arranged and that slots or windows (22a, 22b) for further deflection rollers (32a, 32b) are arranged, on which the first detection means (420) is arranged, which provides information about the amount of ribbon remaining on the associated spool before the ribbon end is reached, and that the deflection rollers (32a, 32b) are resiliently mounted.

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