EP1103382B1 - 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

Description

The invention relates to a method for determining the number of executable with an ink residue normal prints that can be generated by a device with at least one inkjet printhead, according to claim 1 and an arrangement for carrying out the method according to claim 9. The below solution is for the determination the ink supply in ink tank cartridges for postage meters that print with an inkjet printhead and allows the maximum use of the ink until the ink tank cartridge is replaced.

Postage meter machines have been known since the twenties and are still being perfected to this day. The printing principle has changed from original purely mechanical solutions with printing drum to electronic solutions with thermal transfer or inkjet printhead. The franking imprint must be visually and machine readable by the postal authorities to verify the postage payment.

An ink not tested by the manufacturer or not released by him represents a risk to the legibility of the franking imprint. At intervals, the used ink must be replaced with new or the ink cartridge replaced, it being in the interest of the manufacturer's and postal service's customers. if high-quality own material is consumed.

It is already known to indicate an imminent change of consumables via the display. The applicant has already been proposed in German published patent application DE 195 49 376 A1 to use sensors for determining the residual amount of ribbon on ribbon cassettes for a thermal transfer printer or to count the number of impressions by means of the control of the thermal transfer printer. However, this solution is only suitable for a thermal transfer postage meter, for example of the type T1000, and not easily acceptable for franking machines with inkjet printers, because of the non-linear relationship between remaining ink quantity and the number of impressions.

Under the title: Arrangement for ink supply and ink disposal for an inkjet print head, DE 196 13 944 C1 has already proposed an ink tank cassette with two approximately identically constructed ink containers suitable for the type JetMail® postage meter machine. The one ink tank is for disposal, the ink collected during priming. The other ink tank is for ink supply and has two end electrode end detection but does not provide level information either before or after the end signal. A further proposed hole coding does not provide sufficient protection against the use of an ink tank cassette not authorized by the franking machine manufacturer.

An ink end detection with electrodes is previously known from DE 27 28 283 C2. In the bottom of the ink container, two electrodes for a comparative measurement and a separate electrode for a conductivity measurement for ink end signaling are introduced. By means of an electronic Circuit, the contact resistance between these electrodes is measured and evaluated. The electrodes are arranged in troughs, which are formed in the container bottom. The prerequisite for the use of such ink end detection is the use of an electrically conductive ink.
Such sensors for ink end detection provide the franking machine of the applicant of the type JetMail® for safety's sake, a final signal when a maximum of 200 frankings are possible to avoid an incomplete printed due to lack of ink but billed franking print image. Cleaning with ejection (priming) and / or suction of ink is then no longer possible. For a re-order of an ink tank, the end signal is usually given too late on the one hand, when processing large amounts of mail and on the other hand delivered too early when small amounts of mail are processed.

There are already known cassette-shaped container with ink liquid, ink ribbon or toner from US 5,365,312, which have a chip-shaped integrated circuit with an electronic memory for a reservoir identifying code for an expiration date and other data and a counter to the consumption at Print by counting the individual pressure pulses to determine which printed ink drops correspond. The integrated circuit stores the current filling status, which can be read out and displayed by the printer controller. However, 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 of a drop counting is justified but only for printing, where must be expected with very large differences in consumption for various printed images. However, due to the diversity of the print images, no statement can be made about the number of prints still possible with an ink remaining.

EP 875 862 A2 has already proposed an ink jet print head for franking machines which carries an integrated ink tank and a connector with many contacts and a chip for storing a head identification number and a number. The number corresponds to the number of maximum possible franking prints, it being possible to frank with the franking machine only if the head identification number is authorized and the maximum number of franking prints has not yet been reached. This solution can only be used for ink-jet franking machines, because in franking, in particular of stacks of mail, a substantially constant ink consumption is attributed. However, only the consumption of ink is indicated here. However, the user of a postage meter wants to be sure that a billed franking imprint can always be completely printed, i. even if the end of the ink is near. For the JetMail® Applicant's inkjet printing postage meter machines, the above solution is unsuitable. The counting of the (normal) impressions can here therefore provide no information about the number of possible impressions with the ink residue in the ink tank, because with a small to medium number of frankings per day, the consumption of ink by cleaning outweighs what the number reduced at possible impressions per ink tank filling. Piezo inkjet printheads lose a lot of ink when priming and vacuuming, and can not be returned to the head.

In US 5,856,834 an apparatus and method for maintaining ink consumption in an ink cartridge of a postage meter machine has been proposed. The latter has a microprocessor in the meter (vault), in the base and on the printhead. The base microprocessor activates a pump station for cleaning the inkjet printhead and the printhead microprocessor and ASIC for head flushing. The cleaning and rinsing can be done in different intensities. A rinse causes a two to four orders of magnitude reduced ink consumption as opposed to a cleaning, which takes into account purely software by the base microprocessor becomes. A strong rinse "Power Flush" causes a comparable ink consumption, such as a franking imprint with advertising clichés. However, initializing the printhead consumes ten times the amount of ink compared to a high power purge cleaning. Logically, a strong ink consumption would be disadvantageous if there is only a residue of ink in the cartridge. Therefore, the consumption by cleaning and rinsing has been reduced when the ink consumption exceeds a predetermined threshold. Since also a safety factor was taken into account, it is achieved that the remaining amount of ink for a larger number of prints is certainly sufficient. The correspondence between the calculated and the actual consumption deviates more strongly from the predicted end of the ink than at the beginning of the calculation, because not all influencing factors could enter into it. If information on remaining amount of ink was to be determined from the consumption, then the inaccuracy near the end of the ink would be greatest. It can not be predicted for how many normal prints the amount of ink left will suffice. So that the ink does not exhaust earlier than calculated, a safety factor must be chosen sufficiently large. Although refilling the cartridge with ink is possible in principle, the calculation must fail if the refill is carried out inaccurately or incompletely. In this respect, it is disadvantageous if the consumption is calculated only in order to draw conclusions on the remaining ink quantity.

The use of superimposed old inks for refilling and those of poor quality, which are supplied by other manufacturers, in particular so-called pirated products can not be prevented, except when only the single use of the ink tank cartridge is enforced by measures proposed in DE 196 13 945 C2 measures. An ink connection line is docked from the ink jet print head to the container by means of a hollow needle through a rubber elastic closure. A capping device, which serves as a reusability barrier, is irreversibly released upon withdrawal of the container by the hollow needle. A refilled ink reservoir can no longer be docked. Unfortunately, this solution also prevents the reuse of original ink filled recycled containers. The used ink tanks can only be returned to the dealer or service of the manufacturer for proper disposal. The use of precisely copied piracy ink reservoirs can unfortunately not be prevented.

From EP 443 832 A1, it is already known for an ink printer that from a point in time at which a sensor signals a small amount of ink, the number of pages still printable is determined.

The object of the invention is to provide a method for determining the number of normal prints that can be printed with an ink remaining in the ink tank cassette. Four-stroke should be suitable for an ink jet printhead device which must be cleaned at intervals, consuming a quantity of ink that is tolerant. The calculated residual amount of ink should nevertheless deviate so little from the practically available amount at the end of the ink that a final normal print will certainly be completely printed out and that less than that quantity remains in the ink tank cassette needed for a normal print. While use of a refilled ink tank is to be tolerated, the use of overlaid old inks to refill an ink tank or inferior inks of such poor quality is said to be hampered and, as a result, substantially minimized, especially when so-called pirated products.

The object is achieved with the features of the method according to claim 1 or with the features of the arrangement according to claim 9.

The invention is based on the recognition that it is of no interest whether the indication of the available quantity of ink at the beginning of the consumption is accurate. Rather, the exact indication of the remaining quantity with the approach to the end of the consumption interests. This can be done after a rough determination of the remaining amount of ink a message about the number of still possible normal imprints. The prerequisite for such a message is the validity of an entered authorization code for an ink tank cassette. The fine mathematical determination the remaining number of Normalabdrucken takes place only after a predetermined amount of ink remaining sensory detected and signaled. It is envisaged that in the arithmetic determination from a predetermined time, the numbers of rinses and taken at different normal imprints are taken into account and that the remaining number is displayed as an integer number of normal imprints. The sensory detected predetermined residual amount of ink is a certain amount of consumption reserve, which allows a predetermined number of Normalabdrucken from the aforementioned time. A cleaning procedure is prevented when the ink consumption is greater than the ink consumption for a normal print.
The executable with an ink tank filling the replaced ink tank cartridge normal prints are determined in rough approximation and user-specific by the largest consumers detected and the consumption is converted mathematically or empirically obtained data in the appropriate number of franking imprints.
Experience has shown that after each power-up, the amount of postage stamped by a user by means of a franking machine until it is switched off is usually not far from an average number of normal impressions. The latter can vary greatly from user to user. For this reason alone, and since a cleaning cycle with considerable ink consumption is triggered each time it is switched on, there is thus a user-specific average value for the consumption per duty cycle, ie after a switch-on during operation until the franking machine is switched off. Ultimately, empirically results in a user-specific maximum value of achievable normal imprints per ink tank filling. Based on the average user-specific consumption, it is now possible to derive a number of average normal impressions that are still possible. According to the invention, it is provided that a normalized consumption converted in numbers to pseudo-prints or normal imprints is subtracted from a starting number. The rough determination of the number of executable prints is made user-specifically by multiplying the result of the abovementioned subtraction by a yield factor u.

• 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.

The postage meter machine according to the invention is equipped with means for detecting a need to change the consumable (ink, ink tank cassette), wherein upon a change, the validity of an entered authorization code is checked. Only when the use of the ink tank cartridge is authorized, a residual amount of possible impressions is determined and displayed from the beginning. The coarse calculation starts even before a dispensing of an ink end signal, so long before the reserve amount is tapped for consumption.
A pirate protection for consumables has been developed based on its authentication and authorization, which allows the device itself to be checked or externally checked. The device has an input means for the authorization code. The manufacturer supplies a code aggregated with the consumable. If the device franking machine has a chip card read / write unit, the input of code and possibly further data can advantageously be effected by means of the chip card which was supplied with the consumable ink tank cassette. The microprocessor of the device is programmed:

• for the rough arithmetical determination of the number of normal prints which can be executed with an ink residue quantity and for their signaling before a time at which the predetermined remaining ink quantity detected by the sensor is signaled as a reserve,
• to generate a message and display and wait for an input of a code by means of the input means after detecting the change of the ink tank cartridge
• to carry out a check of the entered code for the authorization of the changed ink tank cassette and to change the operation of the device if the verification of the code has resulted in an invalidation and
• for fine arithmetic determination of the number from a time at which the sensor detected predetermined amount of ink remaining is signaled.

For large consumers, signaling in advance is particularly advantageous. Via a user interface, a threshold of signaling be freely programmed as reference value by the user. The use of piracy products or refilled ink tank cartridges eliminates this advantage. The change in the operation of the apparatus may be that the need to change the ink tank cassette is no longer signaled before the reserve quantity is tapped for consumption.

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 presented in more detail below together with the description of the preferred embodiment of the invention with reference to FIGS. Show it:

FIG. 1,

Representation of the user-profile-dependent ink tank yield,

FIG. 2,

Illustration of the back of an ink tank cassette,

FIG. 3,

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

FIG. 4,

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

FIG. 5,

Illustration of the change of the ink tank cassette with the JetMail® type franking machine,

FIG. 6,

Block diagram of the JetMail® franking machine,

FIG. 7,

Flow chart for the JetMail® franking machine,

FIG. 8,

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

FIG. 9,

Flow chart for detecting the change of the ink tank cassette in the JetMail® type franking machine,

FIG. 10,

Subflow plan for determining a yield factor.

FIG. 1 shows an illustration of the user-profile-dependent ink tank yield for the ink tank cassette which is used in the JetMail® type franking machine. After turning on the franking machine, a cleaning (priming) of the ink jet print head is automatically performed. If the postage meter machine is often turned on, with little postage stamped, relatively much ink is consumed by cleaning. However, if the number of normal prints per power-on cycle is increased, that is, in the operation period after a power-on, ink consumption by printing increases relative to ink consumption by cleaning. In addition, the franking machine automatically triggers the cleaning at regular intervals of about 1000 frankings and after prolonged printing pauses, for example after x = 12 hours. This ensures perfect print quality in normal operation. This results in a non-linear curve, as shown in FIG. With all too frequent cleaning, the ink consumption unnecessarily increases, therefore, cleaning automatically proceeds, consuming a predetermined amount of Q _i [in ml] of ink each time. In general, it is clear that a single cleaning for a good print quality before franking is sufficient, if not very much postage is franked. The sum of all amounts Q _{i of} ink used for cleaning consumed reaches a maximum value Q _max for i = n switch-on _cycles . For i <n switch-on cycles, the sum = Q, which can be subtracted from the ink tank filling quantity, so that according to formula (1) the difference D is approximately an ink residue usable in further normal prints and cleanings [in ml]: $$\mathrm{D}=\mathrm{B}-\mathrm{Q}=\mathrm{B}-{\displaystyle \underset{\mathrm{i}=0}{\overset{\mathrm{n}}{\Sigma }}{\mathrm{Q}}_{\mathrm{i}}}\mathrm{}\left[\mathrm{in\; ml}\right]$$

For example, an ink tank container holds an amount B = 360 ml of ink. In extreme cases, a user who franked very little post will be up consumed to 90% of the ink for cleaning operations. The quantity Q _max coincides with the quantity B in a rough approximation. Such small frankers frank less than 50 letters in the shop each time the postage meter machine is turned on. Due to the large number of cleaning processes, a filled ink tank is sufficient for only about 20,000 normal prints. Few frankers are defined as users who make fewer than 200 letters per duty cycle, ie franking in operation after each turn on the postage meter and still consuming 60% to 80% of the ink for cleaning operations. A filled ink tank then suffices for up to approx. 30,000 normal prints.
As a mid-banker users are referred to create less than 1000 letters per duty cycle, ie franking in operation after each turn on the franking machine. If they consume 30% to 60% of the ink for cleaning, a filled ink tank will suffice for more than 50,000 normal prints.
The term "multi-franking" refers to users who create more than 1000 letters per duty cycle, ie frank in operation after each time the franking machine is switched on. Since only 20% to 30% of the ink is consumed for cleaning operations, a filled ink tank will suffice for well over 60,000 normal prints.

The curve in FIG. 1 results from the empirical values of a statistical examination. The latter also provides initial values for the approximate calculation of the residual ink quantity and the resulting number of possible frankings. The amount of ink consumed for a total of franking simply corresponds to the sum of all normal prints A multiplied by the average amount of ink q consumed per single franking [in ml]. Thus, for an ink tank filling amount B: $$\mathrm{B}={\mathrm{Q}}_{\mathrm{Max}}+\mathrm{\Sigma }\mathrm{A}*\mathrm{q}\mathrm{}\left[\mathrm{in\; ml}\right]$$

The quantity of ink Q _max can be converted into a number of dummy prints A 'which are produced by the cleaning operations for franking get lost. Also, the difference D, which results from the equation (1), can then be converted into a number of normal prints, being rounded off to whole normal prints. The difference D is divided into a sum of dummy prints A 'and sum of normal prints A according to the user-specific behavior and a negligible ink residue here: $$\left(\mathrm{\Sigma }{\mathrm{A}}^{\text{'}}+\mathrm{\Sigma }\mathrm{A}\right)\mathrm{q}<\mathrm{B}-\mathrm{Q}\mathrm{}\left[\mathrm{in\; ml}\right]$$

wobei q = 6 F [in ml] und F der Verbrauch an Tinte für eine Spülung ist.Only if the quality of the franking stamp impression is no longer sufficient, for example due to defects in the printed pixels (pixels), cleaning must be exceptionally manually triggered. Thus, the curve shown in FIG. 1 varies very greatly for each user. A pre-calculation of the residual amount of possible normal prints is obviously more problematic than calculating a consumption. A user might be surprised by the premature end of the ink in the ink tank. It must be avoided that an already billed franking imprint can not be printed to the end. An end-of-ink signal is therefore already dispensed when the remaining amount has shrunk to 200 normal prints, the normal prints being, in particular, normal franking prints with an average ink consumption.
The invention now allows the better utilization of this residual amount by a more accurate determination of a residual amount of possible normal prints due to a residual amount of ink in an ink tank, which incorporates both the previous end sensor and based on a more accurate calculation of the ink consumption. Heretofore, in the calculation, the consumption WF of ink for a number W of rinses of the ink jet head has been neglected since it is smaller than the consumption q for an average print A (normal print). From equation (2) it follows: $$\mathrm{B}={\mathrm{Q}}_{\mathrm{Max}}+\mathrm{\Sigma }\mathrm{A}*\mathrm{q}+\mathrm{W}*\mathrm{F}\mathrm{}\left[\mathrm{in\; ml}\right]$$

where q = 6 F [in ml] and F is the consumption of ink for a rinse.

Heavy ink usage is detrimental if there is only a trace of ink left in the ink tank cartridge. Therefore, a generated message appears on the display when the ink supply is no longer sufficient for postage with a printhead cleaning. The latter is the case when the residual amount of ink has shrunk to a value c1 * q, which, for example, allows c1 = 200 normal prints A ₃ when an ink end is detected. There is a consumption q = 6F for normal imprints A = A ₃ . A minimum mark A ₁ causes a lower consumption 4F and a maximum mark A ₅ causes a higher consumption 8F of ink than a normal mark A ₃ . Consumption in between can also have other impressions A2 or A4. Thus, the equation (5) can be established, in which no term for printhead cleaning exists and which is only valid after an end signal has been delivered: $$\begin{array}{l}\mathrm{<figure-callout\; id="1"\; label="c"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">c</figure-callout>}1*\mathrm{q}=\mathrm{<figure-callout\; id="1"\; label="\Sigma \; A"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">\Sigma \; </figure-callout>}{\mathrm{A}}_{}{\mathrm{}}_1*4\mathrm{F}+\mathrm{<figure-callout\; id="2"\; label="\Sigma \; A"\; filenames="imgf0001.png"\; state="\{\{state\}\}">\Sigma \; </figure-callout>}{\mathrm{A}}_{}{\mathrm{}}_2*5\mathrm{F}+\mathrm{<figure-callout\; id="3"\; label="\Sigma \; A"\; filenames="imgf0002.png,imgf0006.png"\; state="\{\{state\}\}">\Sigma \; </figure-callout>}{\mathrm{A}}_{}{\mathrm{}}_3*6\mathrm{F}+\mathrm{\Sigma }{\mathrm{A}}_4*7\mathrm{F}+\mathrm{<figure-callout\; id="5"\; label="\Sigma \; A"\; filenames="imgf0002.png"\; state="\{\{state\}\}">\Sigma \; </figure-callout>}{\mathrm{A}}_{}{\mathrm{}}_5*\mathrm{8th}\mathrm{F}+\mathrm{W}*\mathrm{<figure-callout\; id="1"\; label="F\; c"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">F\; </figure-callout>}& \\ \mathrm{c}\mathrm{}1*\mathrm{q}=200*\mathrm{q}=200*6\mathrm{F}\mathrm{}\left[\mathrm{in\; ml}\right]\end{array}$$

If the remaining number c1 is completely consumed, the equation (6) applies. $$\mathrm{c}1=\left(\mathrm{<figure-callout\; id="1"\; label="\Sigma \; A"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">\Sigma \; </figure-callout>}{\mathrm{A}}_{}{\mathrm{}}_1*2/3+\mathrm{<figure-callout\; id="2"\; label="\Sigma \; A"\; filenames="imgf0001.png"\; state="\{\{state\}\}">\Sigma \; </figure-callout>}{\mathrm{A}}_{}{\mathrm{}}_2*5/6+\mathrm{<figure-callout\; id="3"\; label="\Sigma \; A"\; filenames="imgf0002.png,imgf0006.png"\; state="\{\{state\}\}">\Sigma \; </figure-callout>}{\mathrm{A}}_{}{\mathrm{}}_3+\mathrm{\Sigma }{\mathrm{A}}_4*7/6+\mathrm{<figure-callout\; id="5"\; label="\Sigma \; A"\; filenames="imgf0002.png"\; state="\{\{state\}\}">\Sigma \; </figure-callout>}{\mathrm{A}}_{}{\mathrm{}}_5*\mathrm{8th}/6+\mathrm{W}*1/6\right)$$

Consequently, a number of frankings results when the normalized consumption is subtracted from the remaining number c1 and then rounded off. Flushing reduces ink consumption less than average franking imprint. Since this was taken into account as a normalized figure 1/6, it is achieved that the remaining amount of ink for a larger number of prints with sufficient security and it is alternatively possible to frank smaller amounts in stacks, with the franking of the next batch also a May precede the printing pause. A numerical value Z indicates the differences in consumption between the individual impressions. A normal impression receives the Numerical value Z = 1 and a minimum imprint the numerical value Z = 2/3. Thus, after an end signal has been given, the equation (7) results after each print for the number of remaining impressions: $$\mathrm{K}=\mathrm{c}1-\mathrm{Z}.\mathrm{}\mathrm{in\; which}\mathrm{}2/3\le \mathrm{Z}\le 4/3\mathrm{}\mathrm{is},$$

However, only the full numerical values for K (without decimal places) are displayed to the user. Thus, according to the invention, a precise calculation only starts when an ink end is detected. Without the ink exhausted earlier than calculated, now a possible safety factor can be chosen sufficiently small. The latter can account for an amount of ink consumed for only a single maximum mark A ₅ . A simplification results if Z = 1 is selected and the purging is disregarded, but instead a larger safety factor is selected.

FIG. 2 shows a representation of the rear side of an ink tank cassette of the Jetmaif® type franking machine. An ink tank container 955 of the ink tank cartridge 95 holds approximately 360 ml of ink and serves to supply ink. It is equipped with a pair of electrodes 93,94. An attached sensor 92 provides an ink end signal when the ink tank is empty except for a remaining amount. If now signalisert that the level to be detected falls below, then authorized by the manufacturer ink in the ink tank for ink supply who refilled the. This can be done for example via a hollow needle or syringe through a rubber seal 957 in the rear wall of the ink tank cartridge. Through a second rubber seal 956 in the rear wall of the ink tank cassette 95, the ink sucked in the priming passes into a second ink tank 954 for ink disposal. Hole coding has holes 951 and holes capped with lid 952. Alternatively to the lids, a perforation of the intact back wall can take place. The hole coding protects against confusion with ink tank cassettes that are filled with an ink of a different color. Lateral grooves 958, 959 provide guidance during insertion of 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 commercial lithium battery BAT, which supplies a memory with a memory retention voltage of about 3V. A first switch S1, is operated when removing or changing the consumable. For example, a mechanical contact is opened, which interrupts the power supply of the memory by the lithium battery BAT. This voltage supply is detected and causes the closing of a second switch S2, which is preferably realized as a CMOS circuit. The RESET input of the memory is thereby connected to ground (L level), resulting in the non-volatile storage of the information on an interruption of the presence of the ink tank cartridge by a secure erasure of the memory contents of the memory. Otherwise, when the device is switched on, a positive voltage U _s = +4.5 to + 5V (H level) at the reset input via a resistor R and the diode D1 or a positive voltage U _BAT = +2 via the diode D2 when the device is switched off. 5 to + 3V (H level) on. The memory may be formed as SRAM, which can be equipped by the microcomputer 19 via the interface 18 by means of a - not shown - shift register with a code and can be queried for the presence of the code. The data request for a removal or replacement of the ink tank cassette symbolized by d1, d2 can be supplemented by a data query regarding a mating of the ink tank cassette symbolized by d3. A mechanical contact or first switch S1, which produces the power supply of the memory by the lithium battery BAT, is closed when the cassette is inserted. In addition, the voltage level of the lithium battery BAT can be queried via d3 and window comparators (not shown).

The type of aggregation of the consumable with the codeword preferably depends on the type of consumable. It is intended a sensor, directly or indirectly, permits the presence of consumables to be determined by a physical action principle, the consumable being a solid body. Here, the consumable is the ink in an ink tank cartridge for a postage meter of Fig. 4.

In the perspective view of a franking machine of the JetMail® type illustrated in FIG. 4 from the right, there is an internal data connection to the integrated balance 20. Upstream of the franking machine 1, an automatic feed 3 with an integrated separating device is arranged. A pressure strap 35 can be folded up and then presses on a mail stack, from which 32 letters are separated by means of take-off rollers. Under a hood 34 are more parts of the separating device. A letter abuts on a guide plate 31 and is moved downstream to the guide plate 11 of the postage meter 1, where the printing operation called "franking" takes place. A further moved franked letter is applied to a guide plate 81 of a closing module 8. A closing roller pair 82 ensures the closing of not yet completely closed envelope and for ejection via an insert 5 in the storage box 6. The construction of the franking machine of the type JetMail® has been described, for example, in the non-prepublished German patent application DE 199 00 686.5-27 , under the title: Arrangement for closing envelopes.

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

A microprocessor of the franking machine 1 (not shown) monitors the fill level of an ink tank 95 shown in FIG. 5 by means of an ink end sensor 92. The latter can be in contact with two electrodes according to German Patent 196 13 944 C1. As a precautionary measure, such sensors already provide a final signal in the JetMail if a maximum of 200 frankings are still possible in order to avoid a franking imprint printed incompletely because of lack of ink. If necessary, the microprocessor generates a display text for display in the display 43: THE INK PRESET IS ALMOST USED. PLEASE REPLACE THE TINTANT TANK AS SOON! RESERVE IN PRINT: 200.

The franking machine 1 can now continue to be operated with the reserve ink quantity. The microprocessor realizes in its memory space a backward counter, which is preset by the ink end signal to the number 200 and decremented by one with each additional franking. The number 200 results empirically from empirical values for a balance of possible normal imprints and a safety factor. The number indicating the remainder can be displayed before the next franking. Alternatively, a remainder of possible impressions can be more accurately determined when starting from the aforementioned equation (5). The more accurate calculation will be explained in more detail with reference to FIG.

After each further franking, the microprocessor generates a status line which indicates the number of remaining prints and issues the message at the end: THE INK ADVANTAGE IS REPLIED. PLEASE CHANGE THE TINTANCE TANK.
After opening the flap 99 of the ink compartment 98, the used ink tank 95 can be removed and inserted into a plastic bag, which catches any leaking ink residues. A new ink tank can be removed from the packaging to verify that the color of the ink is correct. For this purpose, a hole coding on the back of the ink tank can be used. At the same time the new codeword will be read. The ink tank is inserted into lateral guide rails (not shown) of the ink tank compartment and pushed in until it noticeably engages. If the ink tank is not inserted correctly, the microprocessor generates the message: PLEASE CHANGE THE TINT TANK!
When docking the new consumables, a contact is automatically closed. The postage meter 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, red florescent, post blue, etc.) can be detected by means of suitably designed contacts. The microprocessor will now generate a message prompting the customer via the display to enter the new code: PLEASE ENTER THE TINT TANK CODE. For example, the customer can take this code from an imprint on the packaging and enter it in the franking machine 1 by means of the keyboard 45.

Now that the franking machine 1 has the new code, a connection with the data center of the manufacturer is made. Today, modern franking machines are all equipped with a modem in order to be able to communicate with the data center of the manufacturer. This is normally used to load a credit amount from the data center if the corresponding storage has been franked. The transmission of the code may be done separately as soon as the new consumable has been identified or may be an additional component of the communication to periodically load the postage meter at a later time. Known measures of data protection are used to prevent the code on the transmission link can be borrowed. The data center receives the code of the new consumable 95 along with an identifier of the postage meter 1. The code comparison performed in the remote data center 100 (not shown) also checks to see if the code has already been used once. Has he been reported by another postage meter has obviously their users are passing the code and the new customer is trying to use unauthorized supplies in combination with that code. If the customer has already given the code before, this is an indication that he has now taken possession of unauthorized after using authorized consumables.
Alternatively, the authorization can be checked in the device itself, which will be explained below with reference to FIG.

FIG. 6 shows a block diagram of a JetMail® type franking machine with a control unit 40 to 58 having a processor 46 and with a base including an integrated balance 20, a rate PROM 22, a modem 53 and such a detector 96. The rate PROM 22 may alternatively be implemented in the dashed memory module 51, 52 within the meter.
The detector 96 recognizes the change or use of a new ink tank cassette 95 according to a direct measuring method. It is also provided that by means of existing sensors 92, 97 in cooperation with an evaluation of measured and stored data carried out by the microprocessor 46 the presence of an exchanged ink tank cassette is determined according to a physically active principle. After a consumption of the ink, a predetermined remainder of ink is detected by means of the electrodes 93, 94 and the sensor 92 and communicated via the modules SAS 59, sensor / actuator control interface ASIC 58 to the microprocessor 46, which then generates a display. There remains a predetermined remainder of ink which is sufficient for about 200 impressions when the conductivity between the contacts 93, 94 falls below a predetermined threshold. Switching the franking machine 1 off / on via the switch 71 can be detected via the sensor 97, which is likewise 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 interchangeable ink tank cassette 95 is indirectly determined. It is envisaged that a save the Number of normal impressions = frankings during operation of the franking machine that the microprocessor of the franking machine recognizes an unauthorized change on the disproportion of the number of admissible frankings and the actual franking performance determined from the entry of the authorization code. Turning off at the time while the postage meter has only the remainder of the ink may indicate an impending change. If the franking machine can then continue to be operated without a change detected via the contacts 93, 94 and the sensor 92 to the restored conductivity between the contacts 93, 94 over a number of 200 normal imprints, then this is an indication that either replaced or in the meantime ink was refilled unauthorized. In response, at least one display is generated and, if appropriate, a message is sent to the data center TDC 100 when a balance needs to be reloaded.

A security module 60 developed by the applicant serves as the first charging module and has a hardware accounting unit 63 and a battery-powered nonvolatile memory 61 in which a credit can be loaded by modem 53. An OTP (One Time Programmable) processor 66 executes security routines both during the credit debit, as well as to secure the register data with a MAC (Message Authentication Code). The advantage of the security module is that the verification of the reliability and approval of the franking and franking machine according to the invention, which is carried out by the mail carrier, then only for the relevant processor system 60 and the connected printer module 55-57 is required. A second processing module forms the smart card 10 in conjunction with the smart card write / read unit 70. The microprocessor 46 and the first memory devices 41, 42 then form a third processing module and the microprocessor 46 and the second memory devices 51, 52 (dashed) then form a fourth processing module, and so on. As a rule, one abandon module is sufficient and the other processing modules can perform other tasks.

The microprocessor 46 with associated memory is used as a postage computer and for printing control and the abort module 60 for accounting and calculation of encryption codes at least for communication with the data center for the purpose of credit recharge. Due to this division of tasks, the bill module 60 has been further developed into the security module. All of the processing modules 41, 42, 51, 52, the security module 60, the microprocessor 46, the interface assemblies 44, 54 and 55, a main memory pixel RAM 47, clock / date module 48, cliché EEPROM 49, program memory ROM 50 and ASIC with the sensor / actuator control interface 58 are connected to a meter-internal BUS 40 of the controller. By means of the keyboard 45 an input is made to the ports of the microprocessor 46 for the corresponding control of the franking machine 1. Via the interface module 44, a generated screen image can reach the display 43. The display has an integrated controller for support. About the sensor / actuator control interface 58 are further - not explained here - sensors and actuators of the base, an encoder 90 for the letter movement and at least one letter sensor 91 and the interface 54 at least the modem 53 electrically to the meter 12 of Franking machine 1 connected. Both interface circuits 54 and 58 can also be implemented in a user circuit ASIC. Further details can be found in EP 716 398 A2, which bears the title: franking machine-internal interface circuit and method for tamper-proof print data control. To control the other components in the base and in the periphery, further embodiments can be taken from EP 875 864 A2, which bears the title: Arrangement for communication between stations of a mail processing machine.
In addition to the letter transporting motor M1, the stripper type motor M2, and the letter closing motor motor M6, there are a motor M3 for the swing mechanism, a motor M4 for a wiper blade, and a motor M5 for an ink pump. Connected to the SAS 59 are a beeper 15 and RDS position sensors which monitor the movement of the Motor M3 for the swing mechanism and thus the movement of a RDS 17 notice. The beeper 15 briefly signals a malfunction, such as pulling the power plug when the print head is not sealed. It uses very little energy for signaling.
The print head is sealed when a sealing cap of the RDS 17 Cleaning and Sealing Station is raised to a sealing position. The latter is not the case in the franking mode, since the print head has been pivoted into a franking position. Cleaning of the printhead is done in conjunction with the control of the three motors M3, M4, M5 mentioned above. Cleaning involves passing through the phases of suction, wiping and free spraying, wherein the passage through the operation of the motor M3 is realized by means of a special mechanism. After a negative pressure has been generated by turning on the ink pump motor M5, a valve 18 is opened by the swing mechanism and sucked a predetermined amount of ink by a priming time period. After priming, the sealing cap is lowered into a wiping position and by driving the motor M4 for the wiper lip, the printhead is wiped. After switching off the ink pump motor M5 is still a free spraying by 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 operation of the RDS 17 has been described in more detail in the German patent DE 197 26 642 C1 entitled: Apparatus for positioning an ink jet printhead and a cleaning and sealing device.

FIG. 7 shows a flow chart for the above franking machine. 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 is called up. Then, branching is made to step 209, possibly via further steps (not shown). In the context of an input and display routine, whereby the input possibilities of the User interface are specified via the screens, more data and commands are entered. Now, a point e before a retrieval step 301 is reached. An input may 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 the query step 301, then the next query step 210 is denied. If it is recognized in the latter that data has been transmitted to the franking machine during the preceding communication, then a return is made to the system routine 200 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 timer is updated for the duration of operation of the postage meter after power up, which is initially set to T: = 0 but is started after power up. The timer can also be updated independently every second.
The command to enter a test mode 213 is detected in a query step 212. The command to enter a display mode 215 is recognized in a query step 214. If the command "switch off" is detected in a query step 216, the print head heating is switched off, the RDS 17 is docked and the valve 18 is closed in a step 217. In addition, the time counter is reset to T: = 0 and the current data is stored Data includes a number H of pseudo-prints corresponding to a normalized consumption and a yielding factor u Immediately after a power-on and after a cleaning procedure has elapsed, in the display mode 215, an actual remaining number M _akt of normal values printed from the values H and u is displayed 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 interrogation step 218 and branched to the display step 219, in the latter case the remaining amount of ink remaining in the form of K prints are displayed. Then, branching is made to the inquiry step 221. If the remaining amount of ink for printing an impression is no longer sufficient, then a branch is made to a step 227. In step 227, the printhead heater is turned off, the RDS 17 is docked, and the valve 18 is closed. Subsequently, a branch back to the system routine via a display step 228. Otherwise, branching is made to a point a for the next interrogation step. Only if the ink end signal is not present can then query steps 220, 222, 224 are passed, which trigger a cleaning of the ink print head.
In query step 220, a counter for the number of impressions started in the start and initialization routine 191 is queried as to whether N = 0 or a predetermined number, for example 1000 impressions, have been printed in order to trigger a slight cleaning.
In the interrogation step 222, the time counter started in the start and initialization routine 191 is queried as to whether a predetermined time duration x, for example x = 12 hours operating time, has been reached in order to initiate a cleaning.
Query step 224 queries if 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. In the latter, it is queried whether the above-mentioned command has been entered again so often in succession that a number Pmax is exceeded. In such a case, in which a multiple cleaning was unsuccessful, the heater is turned off in step 227, the RDS 17 docked and the valve 18 is closed. A step 228 for generating a display "CALL SERVICE" branches back to the system routine 200. Otherwise, an intensive cleaning is triggered, which differs in duration from the others. From the interrogation steps 220, 222, 224, a branch is made to a step 223, in which the heating is switched on, the RDS 17 is docked and the valve 18 is closed. The cleaning of the print head takes place in step 229 and has already been explained in connection with FIG. In a step 230, first, the remaining amount of remaining ink is considered, taking into account at least the cleaning time or intensity Current residual number M _{act converted} to normal imprints 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 it is queried whether another input has been entered, which still has to be processed. Then a loop counter L: = 0 is set, in order then to branch back to the system routine 200.

Otherwise, the loop counter is queried in query step 234 as to whether a predetermined number of loops have been counted. At a certain clock frequency which determines the lap time for a loop, a loop count gives a time, say 10 minutes. If no further entries have been made or processed during this time, the system switches to a standby mode. In a step 237, a standby flag is set, the heater is turned off, the RDS 17 is docked, and the valve 18 is closed and then branched back to the system routine 200. Otherwise, a query step 236 is reached, where it is checked for the presence of a print request. If there is no print request, then, via a step 238 in which the loop counter L: = L + 1 is incremented, branch back to the point s of the system routine 200. Otherwise, a branch to the franking mode 400 is made.

As already stated, on the one hand, the remaining number K of impressions must be calculated more accurately only after the presence of an ink end signal, ie at a low ink level. On the other hand, it is quite sufficient for the provisional information of the user of a franking machine about a current residual number M _akt if the residual quantity calculated in advance at a higher ink level only very roughly matches the actual residual quantity. A residual amount is calculated according to equation (8) as follows: $$\left(\mathrm{c}2-\mathrm{H}\right)*\mathrm{q}=\mathrm{B}-\left(\mathrm{\Sigma }{\mathrm{N}}_{\mathrm{j}}+{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">r</figure-callout>}}_1*\mathrm{\Sigma }{\mathrm{A}}^{\text{'}}+{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="imgf0001.png"\; state="\{\{state\}\}">r</figure-callout>}}_2*\mathrm{\Sigma }{\mathrm{A}}^{"}+{\mathrm{<figure-callout\; id="3"\; label="r"\; filenames="imgf0002.png,imgf0006.png"\; state="\{\{state\}\}">r</figure-callout>}}_3*\mathrm{\Sigma }{\mathrm{A}}^{"}\right)*\mathrm{q}\mathrm{}\mathrm{With}\mathrm{}\mathrm{H}=\left(\mathrm{\Sigma }{\mathrm{N}}_{\mathrm{j}}+{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">r</figure-callout>}}_1*\mathrm{\Sigma }{\mathrm{A}}^{\text{'}}+{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="imgf0001.png"\; state="\{\{state\}\}">r</figure-callout>}}_2*\mathrm{\Sigma }{\mathrm{A}}^{"}+{\mathrm{<figure-callout\; id="3"\; label="r"\; filenames="imgf0002.png,imgf0006.png"\; state="\{\{state\}\}">r</figure-callout>}}_3*\mathrm{\Sigma }{\mathrm{A}}^{"}\right)$$

This results in a current remaining number: $${\mathrm{M}}_{\mathrm{act}}=\mathrm{u}*\left(\mathrm{c}2-\mathrm{H}\right)$$

In step 230, a value H is subtracted from a starting number c2. The value H is normalized consumption converted into units of pseudo-printing or normal imprints, which is stored before the calculation of the remaining number of residues. In the value H, both the number N _{1 is} counted, which resulted from the first cleaning after the start and the number N _j (with j = 2, 3, 4, ...,) between the purifications, as well as in a Number of pseudo-prints A ', A "self-assessed, once identified, factor r ₁ = 1 for easy cleaning factor r ₂ takes into account the cleaning time or intensity of normal cleaning, as opposed to light cleaning Cleaning For example, normal cleaning results in twice as much ink consumption as compared to easy cleaning, while r ₃ factor takes into account the cleaning time or intensity of intensive cleaning, which leads, for example, to doubled ink consumption compared to normal cleaning Factor r ₃ = 4. Without consideration of an initial cleaning, the factor r will then take on numerical values between 1 and 4.

An initial cleaning, which leads to an initial filling of a printhead with ink, may possibly be taken into account in the postage meter machine by means of a changed start number c2. The yield factor u takes into account that only a fraction of the number (c2 - H) is used directly to produce impressions. The user-dependent yield factor u must be stored during initial initialization of the franking machine and lies in the range between 0.1 and 0.8. A high factor u = 0.8 applies here to a user who has been referred to in the explanation of the curve according to FIG. 1 as a multi-receiver.

FIG. 8 shows a flow chart for the franking mode 400 with a billing and printing routine for the JetMail® type franking machine. The determination of a number of normal prints corresponding to a remaining ink remaining is done by the microprocessor 46. If the RDS 17 is not docked (step 401) and the printhead heater is turned on (step 406), the microprocessor 46 starts a calculation of the print image (step 408). Otherwise, if it has been determined in the interrogation step 401 that the RDS 17 is docked, a step 402 is shown. In the latter, the printhead heater is turned on, the RDS is moved to a wiping position and the valve 18 is opened. Then there is a free spraying. If an ink end signal is present, which is queried in step 403, the microprocessor 46 calculates a number K of normal prints in step 404, which can still be executed after the free-spraying. Thereafter, and if there is no end of ink signal, microprocessor 46 drives motor M3 to step 405 to lower the RDS 17 to the depth of the base and pivot the printhead to the print position. The reached position is detected in step 405 via RDS position sensors 16. Subsequently, branching is made to step 408 to calculate the printed image. During the calculation of the print image by the microprocessor 46, the security module 60 is activated. If a piece count credit S> 0 is present after a register check 412 (query step 411) and the check yields proper unmanipulated register data (query step 413), a signature is calculated for the impression (step 416), the printed postage value (step 417) and incrementing the lottery credit (step 418). Otherwise, the OTP processor of the security module 60 switches to statistics and error evaluation (step 414) and generates an indication (step 415) to then branch back to the system routine s.

When the print image has been finally calculated, which is queried in step 409, the microprocessor 46 may insert the signature provided by the security module 60 into the print image (step 420). Subsequently At step 421, the value of Z is determined depending on the selected adware. In the case of a normal imprint, Z = 1. Step 421 is further required to count the imprints printed since the last cleaning operation.

The steps 403, 404, 421, 422, 423 required to determine a number of prints corresponding to a remaining amount of ink still available are part of the aforementioned accounting and printing routine. To roughly determine a number of normal prints, only one increment of the number N is required in step 421. Prior to finely determining a number K of prints, the ink end signal must have been delivered, which is queried in steps 403 and 422. The starting value for K is the remaining number c1. The value K is used to subtract the consumption which can be exactly determined according to equation (6) as a numerical value. The consumption is entered into a pseudo-print number W / 6 for a free-spraying in step 404 and a number Z for an impression in step 423.

Starting from step 423 and if no ink end signal has been issued, which is queried in step 422, then, when the print head is in print position, which is queried via a query step 424, the print engine 426 is reached. The print data passes via the interface 55 and the print controller 56 to the print head 57. An error message is generated in step 425, if it was determined in the latter query that when the print head is not in the print position. Finally, it branches back to the system routine. Between the points a and b of the flow chart according to FIG. 7, further interrogation steps may be present. A not shown polling step results in a step of generating a signaling or warning before the ink tank cartridge needs to be changed. A numerical threshold I on residual normal imprints for a warning / signaling may be preprogrammed by the user by means of the input and print routine 109. The current residual number M _akt at still possible frankings with normal pressures can be found in Display mode 215 are displayed when a corresponding input has been made in the input and print routine 109. If the value M _akt <I, however, a signaling or warning occurs independently of this. Among the other query steps are those that are important in the context of the ink tank cartridge authorization.

Figure 9 shows a flow chart for detecting the change of the ink tank cartridge in a postage meter machine. At point a is a query step 241, which refuses to another query step 242 if the user has just reentered an invalid authorization code. In this case, the further query step 242 asks if an old code has been entered. If no old code has been entered, then a branch is made to a step 244 to store the information, whereby the postage meter recognizes that it is suspicious to work with other than original inks. However, if an old code has been entered, then a query step 243 is branched to store the information in step 244 if the condition M _akt <1 is met. Otherwise, the query step 243 and the query step 241 branches to a query step 245, from which another query step 246 is denied if the user has just reentered a valid authorization code. In this case, in the other inquiry step 246, it is asked whether the ink tank cassette 95 is inserted. If this is not the case or if no authorization code has been entered and the ink tank cassette 95 is not plugged in, then a branch is made to step 250 in order to generate a display text "REPLACE PLEASE TINT TANK". If it is determined in the inquiry step 246 that the ink tank cassette 95 is inserted, then a query step 248 is branched and asked whether an alternating signal is emitted from the detector 96. If this is not the case, then the process branches back to step 250 in order to generate a display text "PLEASE CHANGE TINT TANK". Otherwise, if an alternating signal is emitted from the detector 96, then sets the Microprocessor 46 in step 247, the remaining number M _akt to the initial value c2 and sets the detector 96 in a state in which no change signal is delivered. The entered authorization code is stored as old code.
If it is determined by the inquiry step 249 that the ink tank cassette 95 is not inserted, the step 250 is refrained. Otherwise, a query branch 251 is made if yes. When an AC signal is output from the detector 96, a branch is made to a query step 252 and a request is made as to whether an ink end signal is being output from the sensor 92. If this is the case, then the system branches back to step 250 in order to generate a display text "PLEASE CHANGE TINT TANK". Otherwise, a branch is made to step 253 to generate a display text "ENTER PLEASE TINTENTANK CODE".
Of course, when branching to the step 247, the initial state c2 for the postage meter having a maximum count of the remaining number M is again present because the ink tank cassette has just been replaced with an ink tank cassette 95 filled with original ink of an authorized manufacturer.
When branching to the step 253, the ink tank cassette 95 has been put back after being taken out of the ink tank compartment and is to be reused, for example, because it is not yet empty. If the old authorization code is then input upon request, the above-mentioned reuse is suspect if the current roughly calculated residual number M _akt <1. In fact, in such a case, ie if the ink tank cartridge had not been tampered with by an unauthorized refill, an ink end signal would have been required. From steps 244, 247, 250 and 253, the system routine 200 branches back.

As part of the input and display routine 109, the microprocessor 46 may distinguish the input of an authorization code from other data inputs. It can also compare a stored old code with the entered one. The franking machine leads into In one variant, the authorization check itself or in another variant uses a communication with the data center for authorization check. The codeword is printed on the ink tank cassette or on a label attached to the latter. In addition or as an alternative, the authenticity of a cassette filled with original ink can be checked. For this purpose, further interrogation steps not shown are required. After passing through the interrogation steps 241, 245, 249 and 251 of the subflow plan shown in FIG. 9, the point b is reached again.

FIG. 10 shows a partial flow chart for determining a yield factor u. An interrogation step 261 which interrogates the number of turn-on cycles E = 3 branches to a step 262 to order the number V of tails corresponding to the three turn-on cycles, to size them, and to store the middle value V _m . The calculation step 230 explained in FIG. 7 may include steps to count the number of frankings per duty cycle. If N = 0, an up counter for the number V is started. In step 216, if a power down command is detected, in step 217, the power counter count E of the power up counter may be incremented to E: = E + 1 and stored along with the counter value V of the up counter. After three switch-on cycles, according to the curve of FIG. 1, the user-dependent yield factor u can be determined. Each determined mean value V _m can be assigned a u-factor in a list. The list can be stored in the ROM 50. It suffices to count the respective current number V of frankings per duty cycle. The measured values which have been stored more than three switch-on cycles and which were stored in step 262 are deleted or overwritten in step 263 beforehand.

If an ink tank cartridge with valid authorization code is used, then the need to change the ink tank cartridge again is signaled in advance before the reserve amount is tapped for consumption. 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 is freely programmable by the user and stored in the memory means 41, 42 via microprocessor 46. The storage means 41, 42 are equipped to store at least one threshold value in a memory area. The microprocessor 46 is programmed by a program in the memory 50 to compare the determined number of normal-prints executable with an ink residue with the reference value, and when the reference value is reached or undershot, generate a signal for the need to change the ink tank cassette again. The microprocessor 46 is further programmed to alter the operation of the device if the verification of the authorization code has been invalidated, the change in operation of the device being that the need to change the ink tank cartridge is not signaled in advance.

The codeword can be considered a manufacturer's certificate that guarantees the quality of the ink it contains. For very important components or consumables, the certificate is issued in the form of an electronically readable signature from the manufacturer, away from the data center, which 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 encrypted with the signing key by the manufacturer for signature and printed as codeword. A message containing the identity number of the ink, the amount, possibly the date and the signing key can be transmitted to the data center, which upon receipt of the information transmits a verification key with which the postage meter machine can verify a multiplicity of filled or refilled ink tank cassettes.

It is provided in another variant that the verification or authorization check is performed only in the data center. It is also possible that such checks are performed in both the data center and the postage meter.

The rough computational determination and display of the number of executable normal imprints prior to a time at which the predetermined amount of ink remaining detected by the sensor 92 is signaled is particularly advantageous for users belonging to the group of middle and multiple frankers. The order of a new ink tank cassette must be timely, since a remainder of 200 normal imprints is quickly consumed.

Claims (18)

1. A method for determining the number of normal prints to be produced by an appliance having at least one ink-jet print head (57) that can be made with a residual amount of ink, wherein, from a point of time when a sensor (92) signals a low amount of ink (218), the still printable number of pages is determined (423) in the appliance, characterized in that the numbers of cleaning processes executed and different prints made since the above-mentioned point of time are taken into account in the arithmetical determination and that the remaining number is shown as an integral number of normal prints (219).
2. A method according to claim 1, characterized in that the pre-defined residual amount of ink determined by a sensor is a reserve amount intended for consumption that allows to make a pre-defined number c1 of normal prints; that, from the above-mentioned point of time on, a cleaning procedure with an ink consumption that is higher than the ink consumption for a normal print is prevented; and that an exact arithmetical determination of the number of normal prints that can be made with the residual amount of ink is made from the above-mentioned point of time on.
3. A method according to claim 1, characterized in that, after storing an entered valid authorization code for an ink cartridge, a rough arithmetical determination of the number is made before and a fine arithmetical determination of the number is made as from the point of time when the pre-defined residual amount of ink determined by a sensor is signalled as reserve for printing a pre-defined number.
4. A method according to claim 3, characterized in that a standardized consumption converted into piece numbers H of pseudo prints or normal prints is subtracted from a start number c2 and that the rough determination of the number of executable normal prints is made in a user-specific manner by multiplying the result of the above subtraction by a yield factor u.
5. A method according to claim 4, characterized in that the yield factor u is pre-programmed for the user-specific rough determination of the number.
6. A method according to claim 4, characterized in that the yield factor u for the user-specific rough determination of the number is determined during the operation of the franking machine from a stored list on the basis of a mean number V_m of franking prints per on-state cycle E, wherein the number V of franking prints is registered for a number of on-state cycles E and is used for determining the mean number V_m.
7. A method according to claims 3 to 6, characterized in that a rough determination of the number is made in a user-specific manner and that the necessity to replace the ink cartridge is signalled' upon reaching a pre-defined number of executable normal prints before tapping the reserve quantity for consumption.
8. A method according to claims 3 to 7, characterized by detection of a replacement of the ink cartridge (95) for which an authorization code or a respective chip card (10) with an authorization code is made available and by verification of the validity of the authorization code after entering it by means of the chip card (10) or with the help of the user interface (4).
9. An arrangement for executing the method according to claim 3, comprising a control unit of an appliance, input means (10, 45), an in-jet print head (57) and a cleaning and sealing station (17) as well as a sensor (92) for signalling when a pre-defined residual amount of ink has been reached, wherein the sensor (92) signals the pre-defined residual amount of ink that is tapped as reserve quantity for consumption; wherein the sensor (92) and further means (96, 97) for detecting the presence of a replaced ink cartridge and input means (10, 45) for entering a code are operationally connected to the control unit of the appliance; and wherein the control unit of an appliance contains a microprocessor (46) that is connected with memory means (41, 42 and 50) and is programmed

   - for a rough arithmetical determination of the number of normal prints that can be made with a residual amount of ink and for signalling it before a point of time at which the pre-defined residual amount of ink detected by the sensor (92) is signalled as reserve;

   - for generating a message upon detecting a replacement of the ink cartridge, showing it on the display (43) and waiting for entry of a code by means of the input means (10, 45);

   - for verifying the code entered for authorizing the replaced ink cartridge and for altering the operation of the appliance if the verification of the code has shown its invalidity.
10. An arrangement according to claim 9, characterized in that the display (43) and the input means (45) form a user interface (4) through which a threshold value of signalling is freely programmable as reference value by the user and is stored in the memory means (41, 42) via microprocessor (46).
11. An arrangement according to claims 9 and 10, characterized in that the memory means (41, 42) are designed for storing at least a threshold value in a memory area and that the microprocessor (46) is programmed by a program in the memory (50) for comparing the determined number of normal prints that can be made with a residual amount of ink with the reference value and generating a signal for the necessity to replace the ink cartridge again when said number reaches said reference value or falls below it.
12. An arrangement according to claims 9 to 11, characterized in that the microprocessor (46) is programmed for signalling the necessity to replace the ink cartridge again in advance before the reserve quantity is tapped for consumption if the authorization code is valid and for altering the operation of the appliance if the verification of the authorization code has shown its invalidity, wherein said alteration of the operation of the appliance means that the necessity to replace the ink cartridge is not signalled in advance.
13. An arrangement according to claim 9, characterized in that the means for detecting the presence of a replaced ink cartridge is a detector (96) that detects an interruption of the presence and stores it in a non-volatile manner.
14. An arrangement according to claim 9, characterized in that existing sensors (92, 97) form the means for detecting the presence of a replaced ink cartridge, wherein the presence of a replaced ink cartridge is determined indirectly in interaction with an analysis of measured and stored data by the microprocessor (46).
15. An arrangement according to claim 9, characterized in that, for detecting the replacement of the ink cartridge (95), there are provided a sensor (92) operationally connected to the microprocessor (46) as well as contacts (93, 94) in the tank of the ink cartridge (95), wherein the electric conductivity of the ink is measured between the contacts (93, 94) and the presence of a replaced ink cartridge (95) is determined indirectly in interaction with an analysis of measured and stored data by the microprocessor (46).
16. An arrangement according to claim 9, characterized in that the appliance is a franking machine (1); that the number of normal prints or franking prints is stored during the operation; that the microprocessor of the franking machine identifies the disproportion between the number of admissible franking prints determined since the entry of the authorization code and the actual number of franking prints as an unauthorized replacement and transmits data to the Teleporto Data Center (TDC).
17. An arrangement according to claim 16, characterized in that the data center (100) is provided with a database (110) and with means in the server for verifying the authorization code as well as with means for checking whether the number of normal prints or franking prints is plausible for a cartridge replacement since the last reloading.
18. An arrangement according to claim 9, characterized in that the microprocessor (46) is programmed for a fine arithmetical determination of the number of normal prints that can be made as from a point of time when the pre-defined residual amount of ink detected by the sensor (92) is signalled.

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