EP1103382A2 - Method for the determination of the number of executable normal prints using an ink remain management function and system for performing this method - Google Patents

Abstract

Determining the number of normal impressions or prints which can be made with a residual ink quantity in the ink-tank cassette i.e. using equipment equipped with an inkjet printing head, involves determining the quantity by computer in a time period in which a sensor-detected predetermined residual quantity of ink is signaled as a reserve to the printer.

Description

The invention relates to a method for determining the number of a residual amount of feasible normal prints made by one Device can be produced with at least one inkjet print head, according to the preamble of claims 1 to 4 and an arrangement for Implementation of the method according to the preamble of the claim 10. The solution below is for determining the ink supply in Ink tank cartridges for franking machines applicable with a Inkjet print head and allows maximum use of the Ink until the ink tank cartridge is replaced.

Franking machines have been and have been known since the 1920s still perfected today. The printing principle has changed from original purely mechanical solutions with a printing drum electronic solutions with thermal transfer or inkjet printheads changed. The franking imprint must be visually and by the postal authorities be machine-readable to be able to verify postage payment.

A not tested by the manufacturer or not released by him Ink poses a risk to the legibility of the franking imprint. In The used ink has to be replaced by new ones or the Ink cartridge to be replaced, being in the interest of customers of the manufacturer and the postal services, if high quality own material is consumed.

An upcoming change of consumables is already known shown on the display. The applicant was already in the German published application DE 195 49 376 A1 proposed Sensors for determining the amount of ribbon left on ribbon cartridges to use for a thermal transfer printer or the number of Counting by means of the control of the thermal transfer printer. However, this solution is only for a thermal transfer franking machine, for example of the type T1000, suitable and for franking machines with Inkjet printer not easy to take on because of the non-linear Relationship between remaining ink quantity and number of prints.

Under the title: Arrangement for ink supply and disposal for an ink print head was already in DE 196 13 944 C1 for Franking machine of the type Jetmail® suitable ink tank cassette with proposed two approximately identical ink tanks. The an ink tank is used for disposal, which is collected during priming Ink. The other ink tank is for ink supply and has via an ink end detection with two electrodes, but delivers No information about the fill level before or after the end signal. A hole coding also proposed does not offer sufficient Protection against the use of one from the franking machine manufacturer unauthorized ink tank cartridge.

Ink end detection with electrodes is previously known from DE 27 28 283 C2. Two electrodes for a comparative measurement and a separate electrode for a conductivity measurement for signaling the end of ink are introduced in the base of the ink container. The contact resistance between these electrodes is measured and evaluated by means of an electronic circuit. The electrodes are arranged in depressions which are molded into the bottom of the container. The use of an electrically conductive ink is a prerequisite for the use of such an ink end detection.
For the sake of safety, such sensors for ink end detection already provide the applicant's JetMail® franking machine with an end signal if a maximum of 200 frankings are still possible, in order to avoid a franking print image that is incompletely printed out but billed due to lack of ink. A cleaning with ejection (priming) and or suction of ink is then no longer possible. For a reordering of an ink tank, the end signal is usually delivered too late when large quantities of mail are processed and on the other hand delivered too early when small quantities of mail are processed.

There are already cassette-shaped containers with ink liquid, ribbon or toner from US 5,365,312, which has a chip-shaped Integrated circuit with an electronic memory for one Storage container identifying code, for an expiration date and others Show data as well as with a counter to the consumption at To determine printing by counting the individual printing pulses, which printed ink drops correspond. The integrated circuit saves the current fill status, which is determined by the printer control can be read out and displayed. Reprogramming the chip and refilling the container is not possible. The ink cartridge with chip counts the individual drops and allows use in office printers. The great technical effort a drop count is justified only for printing where with very large differences in consumption for various printed images must be expected. Already because of the diversity of the printed images However, no statement can be made about the number of prints that are still possible with a residual amount of ink.

An ink jet print head for franking machines has already been described in EP 875 862 A2 proposed an integrated ink tank and a Connector with many contacts and a chip for storing one Head identification number and a number. The number corresponds to the Number of maximum possible franking imprints, with the franking machine can only be franked if the header identification number authorized and the maximum number of franking imprints still has not been reached. This solution is only for inkjet franking machines can be used because in franking, in particular from stacks to mail, with essentially constant ink consumption is to be counted. However, here is only the consumption of ink specified. However, the user of a franking machine wants to make sure that a billed franking imprint is always printed out in full can be, i.e. even when the ink end is near. For Inkjet printing franking machines of the applicant of the type JetMail® the above solution is unsuitable. Counting the (normal) Imprints cannot provide any information about the number here possible imprints with the ink remaining in the ink tank because with a small to medium number of frankings per day the Ink consumption by cleaning outweighs the number possible imprints per ink tank filling reduced. For piezo ink jet print heads goes a lot when cleaning with primers and suction lost in ink and cannot be returned to the head.

In US 5,856,834 an apparatus and method for maintenance the ink consumption in an ink cartridge of a franking machine suggested. The latter has in the meter (Vault), in the base and on Printhead each a microprocessor. The base microprocessor activates the Cleaning the inkjet printhead a pump station and for head rinsing the printhead microprocessor and an ASIC. The cleanings and rinses can be done in different intensities become. A rinse causes one to two to four orders of magnitude reduced ink consumption compared to one Cleaning, which the base microprocessor takes into account purely in terms of software becomes. A strong flush "Power Flush" causes a comparable Ink consumption, like a franking imprint with advertising cliché. At however, initialization of the printhead becomes ten times the amount of ink compared to a strong cleaning "Power Purge" consumed. Logically, heavy ink consumption would be disadvantageous if there is only some ink left in the cartridge. Therefore the Consumption through cleaning and flushing reduces when ink consumption exceeds a predetermined threshold. There is also one Safety factor has been factored in, it is achieved that the remaining Amount of ink for a larger number of prints for sure is sufficient. The correspondence between the calculated and the actual Consumption deviates more towards the predicted ink end than at the beginning of the calculation because not all influencing factors are included could. Would provide information about ink remaining from usage then the inaccuracy would be near the end of the ink the biggest. It cannot be predicted for how many normal impressions the remaining amount of ink is sufficient. So that the ink doesn't settle earlier When exhausted as calculated, a safety factor must be sufficiently large to get voted. The cartridge is refilled with ink though possible in principle, but the calculation must fail if the Refilling is inaccurate or incomplete. To that extent it disadvantageous if the consumption is only calculated to get from it To be able to draw conclusions about the amount of ink remaining.

The use of overlaid old inks for refilling and those of poor quality supplied by other manufacturers up to now, especially so-called piracy products be prevented except when the ink tank cartridge is used only once through measures proposed in DE 196 13 945 C2 is enforced. An ink connection line is from the ink printhead to the container by means of a hollow needle through a rubber elastic Closure docked. A cover device that acts as a reusability lock is used when withdrawing the container through the hollow needle triggered irreversibly. A refilled ink reservoir can can no longer be docked. Unfortunately, this solution also prevents that Reuse of recycled containers filled with original ink. The used ink tanks can be disposed of properly only returned to the manufacturer's dealer or service become. The use of exactly copied piracy ink tanks can unfortunately not be prevented.

The object of the invention is to provide a method for determining the Number of normal impressions to be made with one in the ink tank cartridge remaining ink can be printed. The procedure should be suitable for a device with an inkjet printhead that Spaces need to be cleaned, consuming an amount of ink which has a tolerance. The calculated amount of ink remaining should still at the end of the ink from the practically available amount deviate so little that a final normal print with certainty is printed out completely and that less than that amount in the Ink tank cartridge remains, which is required for a normal impression. The use of a refilled ink tank should be tolerated but the use of overlaid old inks for refilling an ink tank or such inks with poor Quality should be difficult and the result should be largely minimized, especially when it comes to so-called piracy products.

The task is carried out with the characteristics of the method according to the Claims 1 and 4 or with the features of the arrangement solved according to claim 10.

The invention is based on the knowledge that it is of no interest whether the amount of available ink at the start of consumption is exact. Rather, the exact specification of the remaining quantity is of interest approaching the end of consumption. So that after a rough determination of the remaining amount of ink a message about the number possible normal prints. Prerequisite for one such notification is the validity of an authorization code entered for an ink tank cartridge. The fine calculation the remaining number of normal impressions is only made after a predetermined amount of ink is sensed and signaled becomes. It is envisaged that in the arithmetical determination the number of flushes performed at a predetermined point in time and be taken into account on different normal prints and that the remaining number as an integer number of normal prints is shown. The sensed predetermined amount of residual ink is a reserve quantity intended for consumption, which is a predetermined one Number of normal prints from the aforementioned point in time enables. A cleaning procedure is prevented if the ink consumption is larger than the ink consumption for a normal print. The one with an ink tank filling of the replaced ink tank cartridge executable normal prints are roughly approximate and user-specific determined by capturing the largest consumers and the consumption arithmetically or based on empirically obtained data in the corresponding number of franking imprints is implemented. Experience has shown that after each switch-on, the up to Switching off franked by a user using a franking machine Post quantity usually not removed from an average number Normal imprints. The latter can be very different from user to user vary widely. For this reason alone and because every time you switch on Cleaning cycle triggered with significant ink consumption results a user-specific average value for consumption per switch-on cycle, i.e. after switching on during operation until Switch off the franking machine. Ultimately, there is empirically a user-specific one Maximum value of achievable normal prints per ink tank filling. From average user-specific consumption starting out, a number of still possible average can now be found Derive normal impressions. According to the invention it is provided that a converted into quantities of pseudo prints or normal prints normalized consumption is subtracted from a number of starts. The rough determination of the number of executable prints is made user specific by using the result of the above subtraction with a fertility factor u is multiplied.

According to the invention, the franking machine has means for recognizing it a need to change consumables (ink, Ink tank cartridge), with the change when changing the validity of an entered authorization code becomes. Only when authorized to use the ink tank cartridge is a remaining amount of possible prints from the beginning determined and displayed. The rough calculation starts before one Output an ink end signal, i.e. long before the reserve quantity is tapped for consumption.

• zur groben rechnerischen Bestimmung der Anzahl von mit einer Tintenrestmenge ausführbaren Normalabdrucken und zu deren Signalisierung vor einem Zeitpunkt, an dem die vom Sensor erfaßte vorbestimmte Tintenrestmenge als Reserve signalisiert wird,
• nach einem Erkennen des Wechselns der Tintentankkassette eine Mitteilung zu generieren und per Display anzuzeigen und auf eine Eingabe eines Codes mittels der Eingabemittel zu warten,
• eine Überprüfung des eingegebenen Codes zur Autorisierung der gewechselten Tintentankkassette durchzuführen und den Betrieb des Gerätes zu verändern, wenn die erfolgte Überprüfung des Codes eine Ungültigkeit ergeben hat sowie
• zur feinen rechnerischen Bestimmung der Anzahl ab einem Zeitpunkt, an dem die vom Sensor erfaßte vorbestimmte Tintenrestmenge signalisiert wird.

Piracy protection for consumables was developed based on its authentication and authorization, which the device checks itself or has checked externally. The device has an input means for the authorization code. The manufacturer provides a code aggregated with the consumables. If the franking machine device has a chip card read / write unit, the code and possibly further data can advantageously be entered using a chip card that was supplied with the ink tank cartridge consumable. The device's microprocessor is programmed:

• for the rough computational determination of the number of normal prints that can be carried out with a residual ink quantity and for their signaling before a time at which the predetermined residual ink quantity detected by the sensor is signaled as a reserve,
• after recognizing the change of the ink tank cartridge, generating a message and displaying it on the display and waiting for a code to be entered using the input means,
• carry out a check of the entered code for authorization of the changed ink tank cartridge and to change the operation of the device if the check of the code has revealed an invalid and
• for fine computational determination of the number from a point in time at which the predetermined amount of ink detected by the sensor is signaled.

For large consumers, signaling in advance is particularly advantageous. A signaling threshold can be set via a user interface freely programmable as a reference value by the user. At the Use of piracy products or refilled ink tank cartridges this advantage disappears. The change in the operation of the device can is that there is a need to change the ink tank cartridge is no longer signaled before the reserve quantity for Consumption is tapped.

Figur 1,

Darstellung der nutzerprofilabhängigen Tintentankergiebigkeit,

Figur 2,

Darstellung der Rückseite einer Tintentankkassette,

Figur 3,

Blockschaltbild des Detektors zum Erkennen des Wechselns einer Tintentankkassette,

Figur 4,

Perspektivische Ansicht einer Frankiermaschine vom Typ JetMail® von vorn rechts,

Figur 5,

Darstellung des Wechselns der Tintentankkassette bei Frankiermaschine vom Typ JetMail®,

Figur 6,

Blockschaltbild der Frankiermaschine vom Typ JetMail®,

Figur 7,

Flußplan für die Frankiermaschine vom Typ JetMail®,

Figur 8,

Flußplan für den Frankiermodus mit Abrechnungs-, Tintenrestmengenbestimmungs- und Druckroutine,

Figur 9,

Flußplan für das Erkennen des Wechselns der Tintentankkassette bei Frankiermaschine vom Typ JetMail®,

Figur 10,

Teilflußplan zur Bestimmung eines Ergiebigkeitsfaktors.

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 1,

Representation of ink tank yield depending on user profile,

Figure 2,

Representation of the back of an ink tank cartridge,

Figure 3,

Block diagram of the detector for detecting the change of an ink tank cartridge,

Figure 4,

Perspective view of a franking machine type JetMail® from the front right,

Figure 5,

Representation of the replacement of the ink tank cartridge with franking machine type JetMail®,

Figure 6,

Block diagram of the franking machine type JetMail®,

Figure 7,

Flow chart for the JetMail® franking machine,

Figure 8,

Flow chart for the franking mode with billing, ink remaining determination and printing routine,

Figure 9,

Flow chart for recognizing the change of the ink tank cartridge in the franking machine of type JetMail®,

Figure 10,

Partial flow chart for determining a fertility factor.

FIG. 1 shows a representation of the ink tank yield dependent on the user profile for the ink tank cartridge which is used in the franking machine of the JetMail® type. After the franking machine is switched on, the inkjet print head is automatically cleaned (primed). If the franking machine is switched on frequently and only a small amount of mail is franked, a relatively large amount of ink is used for cleaning. However, if the number of normal prints per switch-on cycle is increased, ie in the operating period after a switch-on process, the ink consumption by printing increases relative to the ink consumption by cleaning. In addition, the franking machine automatically triggers cleaning at regular intervals of approximately 1000 frankings and after longer printing breaks, for example after x = 12 hours. This ensures perfect print quality in normal operation. This results in a nonlinear curve as shown in FIG. 1. With all too frequent cleaning, the ink consumption increases unnecessarily, for this reason alone the cleaning takes place automatically, with a predetermined amount Q _i [in ml] of ink being used each time. As a rule, it follows that a single cleaning for good print quality before franking is sufficient, if not a lot of mail is franked. The sum of all amounts Q _{i of} ink used during cleaning reaches a maximum value Q _max with i = n switch-on _cycles . With i <n switch-on cycles, let the sum = Q, which can be subtracted from the ink tank filling quantity, so that according to formula (1), the difference D approximately results in a residual ink quantity [in ml] that can be used for further normal prints and cleaning:

For example, an ink tank holds an amount of B = 360 ml of ink. In an extreme case with a user who frankes very little mail, up to 90% of the ink is used for cleaning processes. The set Q _max coincides roughly with the set B. Such little frankers frank less than 50 letters in operation each time the franking machine is switched on. Due to the large number of cleaning processes, a filled ink tank is only sufficient for approx. 20,000 normal prints. Users who create fewer than 200 letters per switch-on cycle, ie frank in operation each time the franking machine is switched on and use 60% to 80% of the ink for cleaning processes, are referred to as low frankers. A filled ink tank is then sufficient for up to approx. 30,000 normal prints.
Medium frankers are users who create fewer than 1000 letters per switch-on cycle, ie frank in operation each time the franking machine is switched on. If you use 30% to 60% of the ink for cleaning processes, a filled ink tank is sufficient for more than 50,000 normal prints.
Frequent frankers are users who create more than 1000 letters per switch-on cycle, ie frank in operation each time the franking machine is switched on. Since only 20% to 30% of the ink is used for cleaning processes, a filled ink tank is sufficient for much more than 60,000 normal prints.

The curve in FIG. 1 results from the empirical values of a statistical investigation. The latter also provides initial values for the approximate calculation of the remaining ink quantity and the resulting number of possible frankings. The amount of ink that is used in total for franking corresponds in a simplified manner to the sum of all normal impressions A multiplied by the average amount of ink q used in individual franking [in ml]. For an ink tank filling quantity B, this results in: B = Q Max + Σ A * q [in ml]

The amount of ink Q _max can be converted into a number of pseudo prints A 'which are lost due to the cleaning processes for franking. The difference D, which results from equation (1), can then also be converted into a number of normal impressions, rounding down to full normal impressions. The difference D is divided into a sum of pseudo prints A 'and a sum of normal prints A according to the user-specific behavior and a negligible ink residue: (ΣA '+ ΣA) q <BQ [in ml]

Only when the quality of the franking stamp imprint is no longer sufficient, for example due to defects in the printed image points (pixels), must the cleaning exceptionally be triggered manually. The curve depicted in FIG. 1 thus varies greatly from user to user. Predicting the remaining amount of possible normal prints is obviously more problematic than calculating consumption. A user may be surprised by the premature end of the ink in the ink tank. It must be avoided that a franking imprint that has already been settled cannot be printed to the end. An end-of-ink signal is therefore already emitted when the remaining amount has shrunk to 200 normal impressions, the normal impressions being in particular normal franking impressions with an average ink consumption.
The invention now allows the better use of this residual amount by a more precise determination of a residual amount of possible normal prints due to an ink remaining amount in an ink tank, which includes both the previous end sensor, and is based on a more accurate calculation of the ink consumption. Until now, the consumption W * F of ink for a number W of rinses of the ink jet head has been neglected in the calculation, since it is smaller than the consumption q for an average print A (normal print). From equation (2) we get: B = Q Max + ΣA * q + W * F [in ml] where q = 6 F [in ml] and F is the consumption of ink for one flush.

Heavy ink consumption is disadvantageous if there is only a remaining amount of ink in the ink tank cartridge. A generated message therefore appears on the display when the ink supply is no longer sufficient for franking with prior print head cleaning. The latter is the case when the residual amount of ink has shrunk to a value c1 * q, which, for example, enables c1 = 200 normal prints A ₃ when an ink end is detected. Consumption q = 6F applies for normal impressions A = A ₃ . A minimum print A ₁ causes a lower consumption 4F and a maximum print A ₅ causes a higher consumption 8F of ink than a normal print A ₃ . Other prints A2 or A4 may be in between. Equation (5) can thus be established, in which there is no term for printhead cleaning and which is only valid after an end signal has been emitted: c1 * q = ΣA 1 * 4F + ΣA 2 * 5F + ΣA 3rd * 6F + ΣA 4th * 7F + ΣA 5 * 8F + W * F c1 * q = 200 * q = 200 * 6F [in ml]

If the remaining number c1 is completely used up, then equation (6) applies. c1 = (ΣA 1 * 2/3 + ΣA 2 * 5/6 + ΣA 3rd + ΣA 4th * 7/6 + ΣA 5 * 8/6 + W * 1/6)

This results in a number of frankings if the normalized consumption is subtracted from the remaining number c1 and then rounded off. Flushing reduces ink consumption less than an average franking imprint. Since this was factored in as a standardized numerical value 1/6, it is achieved that the remaining amount of ink is certainly still sufficient for a larger number of prints and it is alternatively possible to frank smaller quantities in batches, the franking of the next batch also being one Printing pause may precede. The numerical value Z includes the differences in consumption between the individual prints. A normal print receives the numerical value Z = 1 and a minimal print gives the numerical value Z = 2/3. After an end signal has been given, the following equation (7) results after each print for the number of remaining prints: K = c1 - Z, where 2/3 ≤ Z ≤ 4/3.

However, the user is only shown the full numerical values for K (without decimal places). According to the invention, an exact calculation therefore only begins when an ink end is detected. Without the ink running out earlier than calculated, a possible safety factor can now be chosen to be sufficiently small. The latter can make up an amount of ink that is consumed for only a single maximum impression A ₅ . A simplification results if Z = 1 is selected and irrigation is not taken into account, but instead a larger safety factor is selected instead.

Figure 2 shows an illustration of the back of an ink tank cartridge the JetMail® franking machine. An ink tank 955 the Ink tank cartridge 95 holds approx. 360 ml of ink and is used to supply ink. It is equipped with a pair of electrodes 93.94. One thing about it connected sensor 92 provides an ink end signal when the ink tank is empty except for a remaining amount. Is now signaled that the to is below the detection level, then the manufacturer can authorize Refill ink in the ink tank for ink supply. This can be done, for example, using a hollow needle or syringe a rubber seal 957 is made in the rear wall of the ink tank cartridge. Through a second rubber seal 956 in the back of the ink tank cartridge 95 the ink sucked off during priming gets into one second ink tank 954 for ink disposal. A hole coding has holes 951 and holes covered with lid 952. alternative to the intact rear wall can be perforated on the covers. The Hole coding protects against confusion with ink tank cartridges, that are filled with an ink of a different color. Lateral grooves 958, 959 serve as a guide when inserting the ink tank cartridge.

FIG. 3 shows a circuit diagram of a detector which reliably detects the removal or replacement of the consumable even when the device is switched off and is not supplied with system voltage U _s . The detector has a standard lithium battery BAT, which supplies a memory with a memory maintenance voltage of approx. 3V. A first switch S1 is actuated when the consumable is removed or changed. For example, a mechanical contact is opened, which interrupts the voltage supply to the memory by the lithium battery BAT. This voltage supply is detected and causes the closing of a second switch S2, which is preferably implemented as a CMOS circuit. The RESET input of the memory is thereby connected to ground (L level), which leads to the non-volatile storage of the information about an interruption of the presence of the ink tank cartridge by a secure deletion of the memory content of the memory. Otherwise, when the device is switched on, there is a positive voltage U _s = +4.5 to + 5V (H level) at the reset input via a resistor R and diode D1, or a positive voltage UBAT = +2.5 via diode D2 when the device is switched off up to + 3V (H level). The memory can be designed as an SRAM, which can be equipped with a code by the microcomputer 19 via the interface 18 by means of a shift register (not shown) and can be queried for the presence of the code. The data query after the ink tank cartridge has been removed or replaced, symbolized by d1, d2 can be supplemented by a data query regarding whether the ink tank cartridge is plugged in, symbolized by d3. A mechanical contact or first switch S1, which provides the voltage supply to the memory by the lithium battery BAT, is closed when the cassette is inserted. The voltage level of the lithium battery BAT can also be queried via d3 and window comparators (not shown).

The type of aggregation of the consumables with the code word depends preferably depending on the type of consumable. It is intended that a sensor directly or indirectly detects the presence of consumables allows to determine according to a physical principle of action, the consumable being a solid body. Here it is Consumables the ink in an ink tank cartridge for one Postage meter according to FIG. 4.

In the perspective view shown from the right in FIG. 4 There is an internal view of a franking machine of the type Jetmail® Data connection to the integrated scale 20. Upstream of the franking machine 1 is an automatic feeder 3 with an integrated separating device arranged. A pressure bracket 35 can be folded up and then presses on a stack of mail, from which means Take-off rolls 32 letters can be separated. Are located under a hood 34 other parts of the separating device. A letter lies on one Guide plate 31 on and becomes downstream to the guide plate 11 the franking machine 1 moves where the "franking" printing process he follows. A franked letter moved on lies on a guide plate 81 of a locking module 8. A pair of lock rollers 82 provides the sealing of envelope envelopes that are not yet completely closed and for the Ejection via an insert 5 in the storage box 6. The structure of the The franking machine of the JetMail® type is, for example, in the unpublished one German patent application DE 199 00 686.5-27 closer has been described under the title: Arrangement for closing Envelopes.

In the guide plate 11 of the franking machine 1 there are a chip card disk / reader unit 70 and an on / off switch 71 are arranged. After this A chip card 10 can be switched on in connection with the user interface 43, 45 used for simplified setting of the franking machine become. The user interface 43, 45 is located on the meter 12 Franking machine 1. In the German utility model DE 298 21 903 U1, an internationally applicable user interface has been explained in more detail.

A microprocessor (not shown) of the franking machine 1 monitors the fill level of an ink tank 95 shown in FIG an ink end sensor 92. The latter can according to the German Patent 196 13 944 C1 are in contact with two electrodes. Such To be on the safe side, sensors already deliver an end signal in JetMail, if a maximum of 200 franking postings are still possible, for one reason Avoid lack of ink incompletely printed franking image. The microprocessor may generate a display text Indicated on display 43: THE INK SUPPLY IS ALMOST USED UP. PLEASE REPLACE THIS SOON INK TANK! RESERVE IN PRINT: 200.

The franking machine 1 can now continue to operate with the reserve ink quantity become. The microprocessor realizes in its memory space a down counter which is counted to 200 by the ink end signal preset and decremented by one with each additional franking becomes. The number 200 results empirically from empirical values for one Rest of possible normal prints and a security factor. The the remaining number can be used for the next franking Be brought. Alternatively, a rest of possible Imprints can be determined more precisely if from the aforementioned Equation (5) is assumed. The more accurate calculation is based on of Figure 8 explained in more detail.

After each further franking, the microprocessor generates a status line which shows the number of remaining prints and finally issues the message: THE INK SUPPLY IS USED. PLEASE CHANGE THE INK TANK. After opening the flap 99 of the ink compartment 98, the used ink tank 95 can be removed and put into a plastic bag which catches any ink residue that may leak. A new ink tank can be removed from the packaging and checked to ensure that the color of the ink is correct. A hole code on the back of the ink tank can be used for this. At the same time, the new code word can be read. The ink tank is inserted into - not shown - side guide rails of the ink tank compartment and pushed in until it clicks into place. As long as the ink tank is not inserted correctly, the microprocessor generates the message: PLEASE CHANGE THE INK TANK!
When the new consumable is docked, a contact is automatically closed. The franking machine recognizes through this contact that a new consumable has been installed. Depending on a hole coding on the back of the ink tank, the original ink type (post red, fluorescent red, post blue, etc.) can be detected using suitably designed contacts. The microprocessor now generates a message that prompts the customer to enter the new code on the display: PLEASE ENTER THE INK TANK CODE. The customer can, for example, take this code from an imprint on the packaging and enter it into the franking machine 1 using the keyboard 45.

Now that the franking machine 1 has the new code, a connection is established with the manufacturer's data center. Modern franking machines are all already equipped with a modem so that they can communicate with the manufacturer's data center. This is usually used to get a credit amount loaded from the data center if the corresponding memory has been franked frankly. The code can be transmitted separately immediately after the new consumables have been determined or can be an additional component of the communication for periodic remote loading of the franking machine at a later point in time. Known data protection measures are used to prevent the code from being eavesdropped on the transmission link. The data center receives the code of the new consumable 95 together with an identifier of the franking machine 1. When the code is compared in the remote data center 100 (not shown), it is also checked whether the code has already been used. If it was reported by another franking machine, its user obviously passed the code on and the new customer tried to use unauthorized consumables in combination with this code. If the customer has already given the code himself, this is an indication that he has now acquired unauthorized ones after using authorized consumables.
Alternatively, the authorization can be checked in the device itself, which is explained below with reference to FIG. 9.

FIG. 6 shows a block diagram of a franking machine of the JetMail® type with a control unit 40 to 58 having a processor 46 and with a base including an integrated scale 20, a rate PROM 22, a modem 53 and such a detector 96. The rate PROM 22 can alternatively also be implemented in the dashed memory module 51, 52 within the meter.
The detector 96 detects the replacement or use of a new ink tank cassette 95 using a direct measurement method. It is also provided that the presence of a replaced ink tank cassette is indirectly provided by means of existing sensors 92, 97 in conjunction with an evaluation of measured and stored data carried out by the microprocessor 46 is determined according to a physical principle of action. After the ink has been used up, a predetermined residual amount of ink is detected by means of the electrodes 93, 94 and the sensor 92 and communicated to the microprocessor 46 via the assemblies SAS 59, sensor / actuator control interface ASIC 58, which then generates a display. A predetermined remnant of ink remains, which is sufficient for approximately 200 impressions, if the conductivity between the contacts 93, 94 falls below a predetermined threshold value. Switching the franking machine 1 on / off via the switch 71 can be detected via the sensor 97, which is also connected to the SAS 59. In cooperation with an evaluation of measured and stored data carried out by the microprocessor 46, the presence of an ink tank cartridge 95 which has been replaced in the meantime is determined indirectly. It is provided that the number of normal impressions = frankings is stored during the operation of the franking machine, so that the microprocessor of the franking machine recognizes an unauthorized change via the mismatch between the number of permissible frankings determined after the authorization code has been entered and the actual franking service. Switching off at the time when the postage meter machine has only the remaining ink can indicate an impending change. If the franking machine can then continue to be operated beyond a number of 200 normal impressions without a change to the restored conductivity between contacts 93, 94 detected via contacts 93, 94 and sensor 92, then this is an indication that either exchanged or in the meantime, ink has been refilled without authorization. In response to this, at least one display is generated and, if necessary, a message is transmitted to the TDC 100 data center when a credit needs to be reloaded.

A security module 60 developed by the applicant serves as the first Accounting module and has a hardware accounting unit 63 and one battery-supported non-volatile memory 61, in which by modem 53 a credit can be loaded. An OTP (One Time Programmable) processor 66 carries out security routines for both credit reloading, as well as to secure the register data with a MAC (Message Authentication Code). The advantage of the security module is that the reliability check and approval of the Franking and franking machine according to the invention by the Post carrier takes place, then only for the processor system concerned 60 and the connected printer module 55-57 is required. The chip card 10 forms a second processing module in connection with the chip card read / write unit 70. The microprocessor 46 and the first memory components 41, 42 then form a third processing module and the microprocessor 46 and the second memory devices 51, 52 (dashed lines) then form a fourth processing module etc. Usually one accounting module and the others are sufficient Processing modules can take on other tasks.

The microprocessor 46 with associated memories is used as a postage calculator and for pressure control and the accounting module 60 for accounting and calculation of encryption codes at least for communication with the data center for the purpose of reloading credit. Because of this division of tasks, the accounting module 60 has been further developed into a security module. All processing modules 41, 42, 51, 52, the security module 60, the microprocessor 46, the interface modules 44, 54 and 55, a main RAM pixel RAM 47, clock / date module 48, cliché EEPROM 49, program memory ROM 50 and one ASIC with the sensor / actuator control interface 58 are connected to a meter-internal bus 40 of the control. An input to the ports of the microprocessor 46 for the corresponding control of the franking machine 1 is made by means of the keyboard 45. A generated screen image can reach the display 43 via the interface module 44. The display has an integrated controller for support.
Via the sensor / actuator control interface 58 there are further sensors and actuators of the base (not explained in more detail here), an encoder 90 for the letter movement and at least one letter sensor 91, and via the interface 54 at least the modem 53 is electrically connected to the meter 12 Franking machine 1 connected. Both interface circuits 54 and 58 can also be implemented in an ASIC user circuit. More detailed explanations can be found in EP 716 398 A2, which bears the title: Interface circuit internal to the franking machine and method for manipulation-proof print data control. To control the other components in the base and in the periphery, further versions can be found in EP 875 864 A2, which bears the title: Arrangement for communication between stations of a mail processing machine.
In addition to the motor M1 for letter transport, the motor M2 for a strip dispenser and the motor M6 for a letter closer, there is a motor M3 for the swivel mechanism, a motor M4 for a wiper lip and a motor M5 for an ink pump. A beeper 15 and RDS position sensors are connected to the SAS 59, which determine the movement of the motor M3 for the swivel mechanism and thus the movement of an RDS 17. The beeper 15 briefly signals a malfunction, for example when the power plug is pulled out when the printhead is not sealed. It uses very little energy for signaling.
The print head is sealed when a sealing cap of the cleaning and sealing station RDS 17 is raised to a sealing position. The latter is not the case in franking mode since the print head has been pivoted into a franking position. The printhead is cleaned in connection with the control of the three motors M3, M4, M5 mentioned above. Cleaning includes running through the phases of suction, wiping and spraying, the running being realized by the operation of the motor M3 using a special mechanism. After a negative pressure has been generated by switching on the ink pump motor M5, a valve 18 is opened by the pivoting mechanism and a quantity of ink predetermined by a prime time is drawn off. After priming, the sealing cap is lowered into a wiping position and the print head is wiped by actuating the motor M4 for the wiping lip. After the ink pump motor M5 has been switched off, there is still a free spraying in that the piezo actuators of the print head are driven with pulses for a predetermined period of time. If there is no print job, the RDS is docked and the valve 18 is closed. The structure and the mode of operation of the RDS 17 were described in more detail in the German patent DE 197 26 642 C1 under the title: Device for positioning an ink jet print head and a cleaning and sealing device.

FIG. 7 shows a flow chart for the franking machine mentioned above. After the start 190 and the execution of a start and initialization routine 191, the system routine 200 is reached. In step 201, the serial interfaces, for example interface 54, are selected and queried and further stored data are called up. The program then branches to step 209, possibly via further steps (not shown). Additional data and commands are entered as part of an input and display routine, the input options being predefined by the user interface via the screen images. A point e is now reached before a query step 301. An input can be recognized as a communication request in query step 301, whereupon a communication routine 300 is run through before branching back to point e. However, if an input is not recognized as a communication request in query step 301, then the next query step 210 is refused. If it is recognized in the latter that data was transmitted to the postage meter machine during the preceding communication, then a branch back to the system routine 200 is carried out via a statistics and error evaluation mode 211 and an update step 239. Otherwise the system branches to the next query step. In update step 239, a time counter for the duration of operation of the postage meter machine after switching on is updated, which is initially set to T: = 0, but is started after switching on. The time counter can also be updated every second independently.
The command to enter a test mode 213 is recognized in a query step 212. The command to enter a display mode 215 is recognized in a query step 214. If the "switch off" command is recognized in a query step 216, the heating of the print head is switched off in a step 217, the RDS 17 is docked and the valve 18 is closed. In addition, the time counter is reset to T: = 0 and the current data is saved. The current data include a number H of pseudo prints or prints corresponding to a standardized consumption and a productivity factor u. Immediately after switching on again and after a cleaning procedure has elapsed, the current remaining number M _act of normal prints calculated from the values H and u can be displayed in the display mode 215. For this purpose, a rough calculation is carried out, which will be explained in more detail later.
If the sensor 92 emits an ink end signal, the latter is recognized by the microprocessor in the query step 218 and branched to the display step 219, in the latter the remaining ink quantity in the form of
K prints are displayed. The method then branches to query step 221. If the remaining ink quantity is no longer sufficient to print an impression, a branch is made to a step 227. In step 227, the printhead heating is turned off, the RDS 17 is docked and the valve 18 is closed. The system routine is then branched back to via a display step 228. Otherwise, a branch is made to point a for the next query step. Only if the ink end signal is not present can query steps 220, 222, 224 be carried out, which trigger cleaning of the ink print head. In the query step 220, a counter for the number of prints started in the start and initialization routine 191 is queried whether N = 0 or a predetermined number, for example 1000 prints, have been printed in order to trigger easy cleaning.
In query step 222, the time counter started in the start and initialization routine 191 is queried whether a predetermined time period x, for example x = 12 hours of operating time, has been reached in order to trigger cleaning.
Query step 224 asks whether a command has been entered to initiate intensive cleaning. In the case of intensive cleaning, the number of which is counted separately in step 225, a branch is made to query step 226. The latter queries whether the above-mentioned command has been re-entered so many times in succession that a number Pmax is exceeded. In such a case, in which multiple cleaning was unsuccessful, the heating is switched off in step 227, the RDS 17 is docked and the valve 18 is closed. The system routine 200 branches back to via a step 228 for generating a “CALL SERVICE” display. Otherwise an intensive cleaning is triggered, which differs in duration from the others. The query steps 220, 222, 224 branch to a step 223, in which the heating is switched on, the RDS 17 is docked and the valve 18 is closed. The printhead is cleaned in step 229 and has already been explained in connection with FIG. 6. In a step 230, the remaining amount of ink is first converted into a possible current remaining number M _act of normal prints, taking into account at least the cleaning duration or intensity, and then displayed. In the subsequent step 231, the counters are set, for the number of pieces to N: = 1 and for the time to T: = 0. Then the system routine 200 is reached again.
In query step 232, an inquiry is made as to whether another entry has been entered which still has to be processed. A loop counter L: = 0 is then set in order to then branch back to the system routine 200.

Otherwise, the loop counter is queried in query step 234 whether a predetermined number of loops have been counted. With a certain Clock frequency, which determines the lap time for a loop, a number of loops gives a time, for example 10 minutes. Were in no further entries or edits made during this time will be Standby mode switched. In step 237, a standby flag set, the heating switched off, the RDS 17 docked and the valve 18 closed and then branched back to system routine 200. Otherwise, a query step 236 is reached, where there is one Print request is checked. If there is no print request, is via a step 238, in which the loop counter L: = L + 1 is incremented, branched back to point s of the system routine 200. Otherwise, a branch is made to the franking mode 400 at a point d.

As already stated, on the one hand, the remaining number K of impressions only has to be calculated more precisely after the end of an ink signal, ie at a low ink level. On the other hand, it is completely sufficient for the preliminary information of the user of a franking machine about a current remaining number M _act if the remaining amount previously calculated at a higher ink level only coincides very roughly with the actual remaining amount. A residual amount is calculated according to equation (8) as follows: (c2 - H) * q = B - (ΣN j + r 1 * ΣA '+ r 2 * ΣA "+ r 3rd * ΣA ") * q with H = (ΣN j + r 1 * ΣA '+ r 2 * ΣA "+ r 3rd * ΣA ")

This results in a current remaining number: M act = u * (c2 - H)

In step 230, a value H is subtracted from a starting number c2. The value H is standardized consumption converted into numbers of pseudo prints or normal prints, which is saved before the calculation of the remaining number. In the value H, the number of pieces N ₁ , which resulted from the first cleaning after the start and the number of pieces Nj (with j = 2, 3, 4, ...,) between the cleaning operations, as well as the number of pieces, is evaluated cleaning performed on pseudo prints A ', A "is itself evaluated as soon as such is found. The factor r ₁ = 1 applies to light cleaning. The factor r ₂ takes into account the cleaning time or intensity during normal cleaning in contrast to light cleaning For example, normal cleaning leads to a doubled ink consumption compared to light cleaning. The factor r ₃ takes into account the cleaning duration or intensity during intensive cleaning. The latter leads, for example, to a doubled ink consumption compared to normal cleaning r ₃ = 4. Without taking into account an initial cleaning, the factor r takes on numerical values between 1 and 4.

An initial cleaning, which leads to the first filling of a Printhead with ink can, if necessary, in the franking machine by a changed number of starts c2 are taken into account. With the fertility factor u is taken into account that only a part of the number (c2 - H) for Generation of imprints is consumed directly. The user-dependent Productivity factor u must be used when the franking machine is initialized for the first time be stored and is in the range between 0.1 and 0.8. A high factor u = 0.8 applies here to a user who is at the Explanation of the curve according to FIG. 1 was designated as a multiple franker.

FIG. 8 shows a flow chart for franking mode 400 with a Billing and printing routine for the franking machine of the type JetMail®. The determination of a number of normal impressions according to a remaining quantity of ink still available Microprocessor 46. If the RDS 17 is not docked (step 401) and the printhead heater is on (step 406) starts Microprocessor 46 calculates the print image (step 408). Otherwise, if it was determined in query step 401 that the RDS 17 is docked, a step 402 is shown. In the latter, the Printhead heater on, the RDS moves to a wipe position and the valve 18 opened. Then there is a free spray. If one Ink end signal is present, which is queried in step 403, is calculated the microprocessor 46 in step 404 a number K of normal prints, which can still be carried out after the free spraying. Subsequently and if there is no ink end signal, the microprocessor 46 controls the motor M3 in step 405 so far that the RDS 17 in the depth of the Base is lowered and the print head is swiveled into the printing position. The position reached is determined in step 405 via RDS position sensors 16 detected. Then the calculation of the print image is based on the Step 408 branches. During the calculation of the print image the microprocessor 46, the security module 60 is activated. If after a register check 412 there is a quantity credit S> 0 (Query step 411) and the check proper unmanipulated Register data results (query step 413), a calculation is carried out Signature for the reprint (step 416), accounting for the printed Postage (step 417) and incrementing the number credit (Step 418). Otherwise the OTP processor of the security module switches 60 for a statistical and error evaluation (step 414) and generates a display (step 415) to then go to the system routine s to branch back.

When the print image has been computed, what in step 409 the microprocessor 46 can be queried by the security module 60 Insert the supplied signature into the print image (step 420). Subsequently in step 421 the value of Z is dependent on the selected one Advertising slogan determined. In the case of a normal impression, Z = 1. The Step 421 is still required to count the prints that have been made the last cleaning process was printed.

The one for determining a number of prints corresponding to one more available ink remaining steps 403, 404, 421, 422, 423 are part of the aforementioned billing and printing routine. For the rough determination of a number of normal impressions is only one Increment the number of pieces N required in step 421. Before one The ink end signal must determine the number K of prints delivered in steps 403 and 422 is queried. The starting value for K is the remaining number c1. The value K becomes the consumption that can be exactly determined according to equation (6) as a numerical value subtracted. The consumption goes into a pseudoprint number W / 6 for Free spray in step 404 and into a number Z for an impression in step 423 a.

Starting from step 423 and if no ink end signal has been emitted, which is queried in step 422, the print rotine 426 is now reached when the printhead is in the printing position, which is queried via a query step 424. The print data then arrive via the interface 55 and the print controller 56 to the print head 57. An error display is generated in step 425 if it was determined in the latter query that the print head is not in the print position. Finally, the system branches back to the system routine. Further query steps can lie between points a and b of the flow chart according to FIG. A query step, not shown, leads to a step to generate a signal or warning before the ink tank cartridge needs to be replaced. A number threshold value I on remaining normal prints for a warning / signaling can be preprogrammed by the user using the input and printing routine 109. The current remaining number M _akt of frankings that are still possible with normal prints can be displayed in the display mode 215 if a corresponding entry has been made in the input and printing routine 109. If the value M _act <I, however, a signaling or warning occurs regardless of this. The further query steps also include those that are important in connection with the authorization of the ink tank cartridge.

FIG. 9 shows a flow chart for recognizing the change of the ink tank cartridge in a franking machine. At point a there is a query step 241 from which a further query step 242 is refused if an invalid authorization code has just been re-entered by the user. In this case, the further query step 242 asks whether an old code has been entered. If no old code has been entered, a branch is made to a step 244 in order to store the information, as a result of which the franking machine recognizes itself as suspicious of working with non-original inks. If, however, an old code was entered, a branch is made to a query step 243 in order to save the information in step 244 if the condition M _act <1 is fulfilled. Otherwise, a branch is made from query step 243 and query step 241 to a query step 245, from which reference is made to a further query step 246 if a valid authorization code has just been re-entered by the user. In this case, the further query step 246 asks whether the ink tank cartridge 95 is inserted. If this is not the case or if no authorization code has been entered and the ink tank cartridge 95 is not inserted, then a branch is made to a step 250 in order to generate a display text "PLEASE CHANGE THE INK TANK". If it is determined in the query step 246 that the ink tank cartridge 95 is inserted, a branch is made to a query step 248 and the question is asked whether an alternating signal is emitted by the detector 96. If this is not the case, the process branches back to step 250 in order to generate a display text "PLEASE REPLACE INK TANK". Otherwise, if an alternating signal is emitted by the detector 96, the microprocessor 46 sets the remaining number M _akt to the initial value c2 in step 247 and resets the detector 96 to a state in which no alternating signal is emitted. The authorization code entered is saved as an old code.
If query step 249 determines that ink tank cartridge 95 is not inserted, step 250 is returned to. Otherwise, a branch to a query step 251 is yes. If an alternating signal is emitted by the detector 96, a branch is made to an interrogation step 252 and the question is asked whether an end of ink signal is emitted by the sensor 92. If this is the case, the process branches back to step 250 in order to generate a display text "PLEASE CHANGE INK TANK". Otherwise, a branch is made to step 253 in order to generate a display text "PLEASE ENTER INK TANK CODE".
If a branch is made to step 247, the initial state c2 for the franking machine with a maximum count of the remaining number M is of course again because the ink tank cartridge has just been replaced with an ink tank cartridge 95 filled with original ink from an authorized manufacturer.
If a branch is made to step 253, the ink tank cartridge 95 has been plugged in again after it has been removed from the ink tank compartment and is to be used further, for example, because it is not yet empty. If the old authorization code is then entered when prompted, the aforementioned use is suspect if the current roughly calculated remaining number M _akt <1. In such a case, ie if the ink tank cartridge had not been tampered with by an unauthorized refill, an ink end signal should have been present. Steps 244, 247, 250 and 253 branch back to the system routine 200.

The microprocessor can be used as part of the input and display routine 109 46 entering an authorization code from other data entries differentiate. It can also save a saved old one Compare code with the entered one. The franking machine leads into the authorization check itself in one variant or uses it in one Another variant is communication with the data center for the authorization check. The code word is printed on the ink tank cartridge or on a label attached to the latter. Complementary or alternatively, the authenticity of a cartridge filled with original ink can be checked become. This requires further query steps, not shown the execution of the query steps 241, 245, 249 and 251 of the In the partial flow diagram shown in FIG. 9, point b is reached again.

FIG. 10 shows a partial flow chart for determining a productivity factor u. A query step 261, which queries the number of switch-on cycles E = 3, branches to a step 262 in order to sort the number V of frankings according to the three switch-on cycles, and to store the mean value V _m . The calculation step 230 explained in FIG. 7 can contain steps to count the number of frankings per switch-on cycle. If N = 0, an up counter for the number V is started. If a switch-off command is detected in step 216, the counter value E of the switch-on cycle counter can also be incremented to E: = E + 1 in step 217 and stored together with the counter value V of the up-counter. After three switch-on cycles, the user-dependent productivity factor u can be determined in accordance with the curve in FIG. A u-factor in a list can be assigned to each determined mean value V _m . The list can be stored in the ROM 50. It is sufficient to count the current number V of frankings per switch-on cycle. The measured values more than three switch-on cycles back, which were saved in step 262, are deleted in step 263 or overwritten beforehand.

If an ink tank cartridge with a valid authorization code is used, then the need to change the ink tank cartridge again signaled in advance before the reserve quantity for consumption is tapped. The display 43 and the input means 45 form one User interface 4, via which a threshold signaling is freely programmable by the user as a reference value and in the storage means 41, 42 is stored via microprocessor 46. The storage media 41, 42 are equipped, at least one in a storage area Save threshold. The microprocessor 46 is through a program programmed in memory 50, the determined number of with an ink remaining amount executable normal prints with the reference value compare and if the reference value is reached or undershot, a signal for the need to replace the ink tank cartridge to generate. The microprocessor 46 is still programmed to change the operation of the device if the check of the Authorization codes have shown its invalidity, the change the operation of the device is that the need a change of the ink tank cartridge is not signaled in advance.

The code word can be viewed as a certificate from the manufacturer who the quality of the ink contained is guaranteed. For very important components or consumables, the certificate is in the form of an electronic legible signature issued by the manufacturer away from the data center, who has a so-called signing key and the Data center database has a verification key. The Identity number of the ink and the quantity sold are shown with the Signing key encrypted by the manufacturer for signature and as a code word printed on. A the identity number of the ink, the amount, if applicable the Date and the key included message can go to the data center be transmitted, which upon receipt of the information a verification key transmitted with which the franking machine a variety of filled or refilled ink tank cartridges.

In a further variant it is provided that the verification or authorization check is carried out only in the data center. It is it is also possible that such reviews in both, i.e. in the data center and carried out in the franking machine.

The rough calculation and display of the number executable normal prints before a time when the Sensor 92 detected predetermined ink remaining is signaled particularly advantageous for users belonging to the group of middle and Frequent frankers belong. Ordering a new ink tank cartridge must be done in time, as a rest of 200 normal prints quickly is used up.

The invention is not limited to the present embodiment. Rather, a number of variations are within the scope of the claims conceivable. So obviously other other versions of the Invention are developed or used by the same Basic ideas of the invention, starting from the attached Claims are included.

Claims (19)

Method for determining the number of normal prints which can be carried out with a residual ink quantity and which can be produced by a device with at least one ink jet print head, characterized in that the number is determined mathematically from a point in time at which a sensor-determined predetermined residual ink quantity is available as a reserve for printing a predetermined one Number is signaled. Method according to Claim 1, characterized in that the number of flushings carried out from the aforementioned point in time and on different impressions is taken into account in the computational determination, and in that the remaining number is displayed as an integer number of normal impressions. A method according to claim 1, characterized in that the sensor-determined predetermined amount of residual ink is a reserve amount intended for consumption, which enables a predetermined number c1 of normal prints, that from the aforementioned point in time a cleaning procedure with an ink consumption which is greater than the ink consumption for is prevented is a normal print and that a precise mathematical determination of the number of normal prints that can be carried out with the remaining ink quantity takes place from the aforementioned point in time. Method for determining the number of normal prints which can be carried out with a residual ink quantity and which can be produced by a device with at least one ink jet print head, characterized by a rough calculation of the number after storing an entered valid authorization code for an ink tank cartridge before and a fine calculation of the number from a point in time , on which the sensor-determined predetermined amount of ink is signaled as a reserve for printing a predetermined number. A method according to claim 4, characterized in that a normalized consumption converted into piece numbers H of pseudo prints or normal prints is subtracted from a starting number c2 and that the rough determination of the number of executable normal prints is carried out in a user-specific manner by the result of the aforementioned subtraction with a productiveness factor u is multiplied. Method according to claim 5, characterized in that the productivity factor u is preprogrammed for the user-specific rough determination of the number. Method according to Claim 5, characterized in that the yield factor u for the user-specific rough determination of the number during the operation of the franking machine is determined from a stored list on the basis of an average number V _m of frankings per switch-on cycle E, E for a number of switch-on cycles the number V of frankings is detected and the average number V _{m is} determined therefrom. Method according to claims 4 to 7, characterized in that the number is determined roughly in a user-specific manner and that, given a predetermined number of executable normal prints, the need to change the ink tank cartridge is signaled before the reserve quantity is tapped for consumption. Method according to claims 4 to 8, characterized by detecting a change of the ink tank cartridge (95) for which an authorization code or an associated chip card (10) with an authorization code is already being provided, and by checking the validity of the authorization code after it has been read using the Chip card (10) or using the user interface (4) was entered. Arrangement for carrying out the method according to claim 4, with a control unit of a device, with input means (10, 45), an inkjet print head (57) and a cleaning and sealing station (17) and with a sensor (92) for signaling when a predetermined Ink remaining quantity is reached, characterized in that the sensor (92) signals the predetermined ink remaining quantity, which is tapped as a reserve quantity for consumption, that with the control unit of the device the sensor (92) and other means (96, 97) for determining the presence of an exchanged ink tank cartridge and input means (10, 45) for inputting a code are operationally connected so that a microprocessor (46) with memory means (41, 42 and 50) is connected and programmed in the control unit of the device, for coarse calculation of the number of normal prints that can be carried out with a residual ink quantity and for signaling them before a time at which the predetermined residual ink quantity detected by the sensor (92) is signaled as a reserve, after recognizing the change of the ink tank cartridge, generating a message and displaying it on the display (43) and waiting for an input of a code by means of the input means (10, 45), carry out a check of the entered code for authorization of the changed ink tank cartridge and to change the operation of the device if the check of the code has revealed an invalid. Arrangement according to claim 10, characterized in that the display (43) and the input means (45) form a user interface (4) via which a threshold value of the signaling as a reference value can be freely programmed by the user and in the storage means (41, 42) via Microprocessor (46) is stored. Arrangement according to claims 10 and 11, characterized in that the memory means (41, 42) are equipped to store at least one threshold value in a memory area and that the microprocessor (46) is programmed by a program in the memory (50) which compare the determined number of normal impressions which can be carried out with a residual ink quantity to the reference value and, if the reference value is reached or undershot, generate a signal for the need to replace the ink tank cartridge again. Arrangement according to claims 10 to 12, characterized in that the microprocessor (46) is programmed to signal in advance, if the authorization code is valid, the need to change the ink tank cartridge again before the reserve quantity is tapped for consumption and to stop the operation of the device change if the verification of the authorization code has shown its invalid, the change in the operation of the device is that the need to change the ink tank cartridge is not signaled in advance. Arrangement according to claim 10, characterized in that the means for determining the presence of a replaced ink tank cartridge is a detector (96) which detects an interruption of the presence and stores it in a non-volatile manner. Arrangement according to Claim 10, characterized in that existing sensors (92, 97) are the means for determining the presence of an exchanged ink tank cartridge, the presence of an exchanged one being indirectly influenced in cooperation with an evaluation of measured and stored data carried out by the microprocessor (46) Ink tank cartridge is detected. Arrangement according to claim 10, characterized in that a sensor (92) and contacts (93, 94) operatively connected to the microprocessor (46) and contacts (93, 94) are provided in the tank of the ink tank cartridge (95) for detecting the change of the ink tank cartridge (95), wherein the electrical conductivity of the ink between the contacts (93, 94) is measured and, in cooperation with an evaluation of measured and stored data carried out by the microprocessor (46), the presence of an exchanged ink tank cartridge (95) is determined indirectly. Arrangement according to claim 10, characterized in that the device is a franking machine (1), that the number of normal prints or frankings is stored during operation, that the microprocessor of the franking machine detects the disproportion of the number of permissible values determined after the authorization code has been entered Franking and the actual franking service recognizes an unauthorized change and provides data for data transmission to the Teleporto data center (TDC). Arrangement according to claim 17, characterized in that the data center (100) is equipped with a database (110) and means in the server for checking the authorization code and has means for checking whether the number of normal prints or frankings has been plausible for a cassette change since then last reload is. Arrangement according to claim 10, characterized in that the microprocessor (46) is programmed for the fine computational determination of the number of executable normal prints from a point in time at which the predetermined amount of ink detected by the sensor (92) is signaled.

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