EP1176016A2 - Device and automated adjustment method for warming cycles of inkjet heads - Google Patents

Abstract

Re-writable memory (200, 210) has an area storing heating data for the ink jet head (2101) and a further area storing predetermined conditions relating to temperature, history and/or user selections. The control unit (14) is programmable. Surrounding temperature is measured with a sensor (2119). All data are combined, to control the ink-jet head temperature for a rapid start. An Independent claim is included for the corresponding method of operation.

Description

The invention relates to an arrangement for data tracking for Warm-up cycles of inkjet printheads according to the preamble of Claim 1 and a method according to the preamble of Claim 10. The invention comes in ink jet printing devices for use, for example in franking machines with inkjet print heads, printing stations of a mail processing machine or other printing devices.

DE 196 05 015 C1 (US 5,949,444) has already explained the printing device of the franking machine JetMail®, which performs franking printing in the case of a non-horizontal, approximately vertical letter transport by means of an ink jet print head arranged in a recess behind a guide plate. A trigger sensor for the printing process is located just before the ink jet printhead recess. It is used to identify the start of a letter and interacts with an incremental encoder for path control. The printing process is triggered by a light barrier of the franking machine JetMail® (EP 901 108 A2). The front edge of even particularly thick mail items is thus clearly recognized. The JetMail® also uses other optical sensors for mail item jam detection and route control. In addition to the aforementioned sensors, at least one sensor of a printing block is used, which, like a heating resistor, is also connected to the franking machine control via an internal franking machine interface circuit. An interface circuit internal to the franking machine has already been presented in EP 716 398 A2 (US 5,710,721). The printing block contains, for example, three ink printing modules. The ink printing modules are arranged according to a solution communicated in EP 713 776 B1 (US 5,757,402) between the identically constructed circuit modules, the latter each carrying a heating resistor and a sensor. In order to guarantee a high print quality of the franking machine JetMail® even at low ambient temperatures, the printing block and thus also the ink are preheated to a predetermined temperature. Printing is only permitted within a certain temperature range, because the temperature of the ink has a significant influence on the drop formation when the ink is ejected. If the ambient temperature is at a temperature T _error = 0 ° C below the minimum operating temperature T _min = 32 ° C of the JetMail®, damage to the print head can occur due to excessive temperature differences during heating. Above the maximum operating temperature T _max = 50 ° C of the JetMail®, the print quality deteriorates. In both cases, at least one error message is issued. There is thus a contradiction between high print quality and immediate operational readiness of the printing device

Other ink-jet printers or franking machines with ink-jet printing technology, for example with bubble-jet technology, must first reach a predetermined operating temperature before the printing block or printer is released for printing. A sensor constantly measures the temperature in the ink printhead. The specific warm-up data are determined for each ink cartridge each time the device is switched on. A repeated free spraying is carried out cyclically, thereby spraying a large volume of ink. For the purpose of ink splashing, it is necessary to electrically heat a heating resistor near a nozzle so that part of the water in the water-based ink evaporates suddenly (bubble jet principle). The ink jet print head is controlled with pressure voltage pulses of approx. 12 V and a duration of approx. 1.9 - 2.3 µs. This accelerates an ink drop to the surface of a print carrier or, in the absence of the latter, to the opening of an ink sump container. Local heating also leads to a gradual rise in temperature in the wider area around the heating resistor. A pause in pressure, however, leads to a gradual drop in temperature. In particular, an ink-jet printer that is connected to a personal computer that is restarted daily requires an excessively long preparation time for the printing task. With ½ inch ink jet cartridges, for example, 22 temperature values of the printhead are measured after switching on, each of which corresponds to a pressure pulse voltage value. Each nozzle is triggered a thousand times per measurement with the respectively set pressure pulse voltage value. In the next measurement, the nozzle is actuated a thousand times with a pressure pulse voltage value that is set lower in each case. The course of the temperature curve measured in this way is evaluated. The resulting print pulse voltage value is used for subsequent printing. The ambient temperature also has an influence on the measurement (Fig. 5). The preparation time thus required then has a predetermined duration of approx. 1 min.
Otherwise, if it could be started from a standby mode for the inkjet printer, this could allow the printing task to be carried out immediately. The correct operating temperature of 15-40 ° C is maintained if the ink jet print head is operated in standby mode without printing on a print carrier. During printing during a shorter pause or in standby mode, the operating temperature can be maintained by electrically heating the heating resistor near each nozzle so that little or no water of the water-based ink evaporates. An energy pulse of approx. 0.75 µs is then only sufficient for warming up (pulse warming-up), but not yet for printing. In the interest of a longer cartridge life, the PWU method (pulse warming-up) is also used after switching on. Even at an ambient temperature range of 10-40 ° C, a warm-up time must be waited for if an operating temperature of approx. 45 ° C is to be reached again. A longer period of time must be maintained below the specified range of the ambient temperature. A predetermined operating temperature can also be maintained with a stronger energy pulse, which is additionally supplied at intervals in which no printing takes place, which on the one hand allows immediate printing. On the other hand, a stronger energy pulse> 2 µs leads to ink splashing. The ink supply of a cartridge is limited to approx. 42 ml and is therefore used up in standby mode. Since the ink cartridges hold a much smaller volume of ink than, for example, the ink tank of the JetMail® franking machine, the ink cartridge life would be significantly reduced by any additional ink consumption during warm-up.

From US 5,625,384 is an inkjet printer with interchangeable Ink printheads are known, being used during the production of the cartridges determines the characteristic data of each particular head and stored in the ROM on the head, i.e. before a first time Place in the inkjet printer. The head operating conditions can to be called automatically. The exchange of heads will automatically recognized based on identification information. One again However, a replaced ink printhead cannot work with the optimal one Head conditions are operated when too long a period of time for replacement has passed. When the replacement Ink printhead could only have a remaining ink supply however, refrain from restoring conditions that a guarantee long life of the ink printhead. However there is no possibility of the period after the replacement until Shorten the head again and the latter will always operated with the same data stored during production.

The invention has for its object an arrangement and a Data tracking method for inkjet printhead warm-up cycles to develop the one with less ink consumption faster operational readiness and satisfactory print quality principally enables.

The task is performed with the features of the arrangement according to the claim 1 and solved with the features of the method according to claim 10.

• eine temperaturbezogene Datennachführung durch eine im Speicher hinterlegte Anhängigkeit oder durch eine Berechnung nach einem im Speicher hinterlegten Algorithmus,
• eine vergangenheitsbezogene Datennachführung durch eine im Speicher hinterlegte Anhängigkeit oder durch eine Berechnung nach einem im Speicher hinterlegten Algorithmus und/oder
• eine userbezogene Datennachführung entsprechend einer Benutzereingabe von Daten in den Speicher und Aufrufen von Betriebsparametern in Abängigkeit von der vom Benutzer getroffenen Auswahl.

It is envisaged that the printhead characteristics are determined in the machine itself and stored in a writable memory in order to program the machine appropriately for the head that is inserted into the machine for the first time. The print head characteristics do not have to be determined again in the machine for an exchanged and reinserted ink jet print head. Ink cartridges are preferably used which have an ink reservoir, an ink jet print head and a non-volatile memory. For different ink cartridges, optimal warm-up data WUD (warming up data) are determined and saved by a machine control system. Not only the ambient temperature but also other conditions may have changed when an ink cartridge is reused later and are taken into account according to the invention. For example, a read-out ink cartridge serial number can be stored in the memory of a franking machine together with associated warm-up data WUD when an ink cartridge is started up for the first time, which can subsequently be adapted to the changed conditions. Additionally or alternatively, this warm-up data WUD can be stored on a memory chip of an ink cartridge.
If optimal warm-up data WUD have already been determined, the warm-up cycles can be reduced the next time you switch on, by:

• temperature-related data tracking by means of a dependency stored in the memory or by a calculation based on an algorithm stored in the memory,
• a past-related data update by means of a dependency stored in the memory or by a calculation based on an algorithm stored in the memory and / or
• a user-related data update according to a user input of data into the memory and calling up operating parameters depending on the selection made by the user.

• temperatur- und vergangenheitsbezogene Nachführung,
• temperatur- und user-bezogene Nachführung sowie die
• temperatur- und vergangenheits- und user-bezogene Nachführung.

Eine Frankiermaschine oder ein Ink-Jet-Drucker gestatten via Userinterface eine Benutzereingabe, um eine stufenweise wählbare Einstellung zwischen einer höheren Lebensdauer der Kartusche oder einer schnelleren Betriebbereitschaft im Falle eines Schnellstartes einzugeben. Der Zeitabschnitt nach dem Wiedereinwechseln bis zum Wiederbetrieb jeder Kartusche hat damit eine vom Benutzerwunsch abhängige wählbare Länge, wobei eine kleiner gewählte Länge die Lebensdauer der Kartusche reduziert. Die user-bezogene Nachführung ist auf den aktuellen Eingabewunsch bezogen. Bei den user-bezogenen Daten wird die Veränderung des Temperaturverhaltens des Kopfes der Tintenkartusche durch die Umgebungstemperatur entsprechend mit berücksichtigt.If the warm-up data for a specific ink cartridge were stored under the first conditions when it was commissioned, the associated warm-up data can be determined in the second condition the next time it is switched on, without having to measure a physical state several times. A current second condition includes at least the ambient temperature and the head temperature when switching on. If the measurement temperature is between two temperature points in the table, the microprocessor can interpolate the warm-up data. Data tracking is possible in three combinations:

• temperature and past related tracking,
• temperature and user-related tracking as well as the
• temperature and past and user-related tracking.

A franking machine or an ink jet printer allow user input via the user interface in order to enter a step-by-step setting between a longer service life of the cartridge or faster operational readiness in the event of a quick start. The period of time after replacing each cartridge until it is in operation again has a selectable length that is dependent on the user request, a shorter length reducing the life of the cartridge. The user-related tracking is based on the current input request. In the case of the user-related data, the change in the temperature behavior of the head of the ink cartridge due to the ambient temperature is taken into account accordingly.

The ink consumption / use of each ink cartridge and the aging are past conditions that are automatically taken into account by the franking machine. Aging does not only occur due to the length of time the head is operated, but also becomes full when not in use. An expiry date for the ink cartridge is stored non-volatilely in each of the ink cartridges by the manufacturer of the franking machine. For example, an internal calendar clock of the franking machine can be used to determine the aging. Before the expiration date, use of the ink cartridge will decrease its value. As a result, it seems justified to start faster at the expense of the cartridge life.
You can also determine whether the ink cartridge has expired. In such a case, the controller is programmed to automatically carry out a quick start at the expense of the cartridge life, which allows the time period until the cartridge to operate again to be reduced to a minimum length.
As an alternative to the expiry date for the ink cartridge, a number of n days can be stored in a non-volatile manner as a limit value in each of the ink cartridges. The latter is decremented daily until a number of zero days is reached. If the specified limit values on days are not reached, it is possible to carry out a correspondingly faster start at the expense of the service life of the cartridge.
Conversely, another variant works as follows: A number of n days is stored as a non-volatile limit and a counter is incremented daily until a number of days is reached which corresponds to the aforementioned limit. If predetermined limit values are exceeded on days or again, it is possible to carry out a correspondingly faster start at the expense of the service life of the cartridge.
The data relating to the past take into account the change in temperature behavior due to use and aging of the ink cartridge.
This temperature-related, past-related and / or user-related data tracking requires warm-up data which are assigned to the current condition data in a table. They are supplied by sensors and memory, possibly by a clock / date module. The microprocessor of the control of the printing device carries out a determination of the ambient temperature, the head temperature, the fill level, the length of time the head is operated up to the current date and the user request and selects or calculates warm-up data.

Figur 1,

perspektivische Ansicht einer Frankiermaschine mit einer Tintenkartusche,

Figur 2,

Tintenkartusche,

Figur 3,

Blockschaltbild des elektronischen Halbleiterchips für den Kopf,

Figur 4,

Blockschaltbild mit einer Kontaktiereinheit und der elektronischen Steuereinheit der Druckvorrichtung,

Figur 5,

Temperatur/Spannnungs-Diagramm,

Figur 6,

Flussdiagramm zur Datennachführung für Aufwärmzyklen von Tintenstrahldruckköpfen.

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

Figure 1,

perspective view of a franking machine with an ink cartridge,

Figure 2,

Ink cartridge,

Figure 3,

Block diagram of the electronic semiconductor chip for the head,

Figure 4,

Block diagram with a contact unit and the electronic control unit of the printing device,

Figure 5,

Temperature / Span-drying diagram

Figure 6,

Flow chart for data tracking for warm-up cycles of inkjet printheads.

FIG. 1 shows a perspective view of an open one at the top Franking machine 1. The franking machine 1 has a slot-shaped Opening 3 in its housing 4. The direction of transport for a supplied - Mail item not shown is marked by an arrow and runs from top left to bottom right. The mail piece arrives at further transport to rest against a guide plate 2 of the franking machine 1. The open housing 4 shows two in the printing position positioned ½ inch inkjet printheads. The latter each have one own data and ink storage and are therefore also called Ink cartridges called. An ink storage container holds approx. 40 ml Ink. The connection side of the ½ inch ink cartridges 21, 22 is in trained in a predetermined manner. Corresponding tax and Contacting units 211 and 221 are for electronic signal conversion and electro-mechanical connection to the connection side of the ½ inch Ink cartridges 21, 22 adapted.

FIG. 2 shows an ink cartridge 21, which is an electronic semiconductor chip 2100 in a head that hangs on a neck 2103. The head has a nozzle plate 2104 in the ejection direction and orthogonal a parallel interface with an electrical contact unit 2105 to control the inkjet print head. The ink cartridge 21 has a bulbous ink reservoir 2106 as an ink storage and opposite an electronic memory chip 210 for storage warm-up data of the ink jet print head 21 with electrical Contacts 2107 for querying the warm-up data, the fill level data and more data. The latter include a manufacturer identification number which is checked by the control unit of the printing device whether a valid ink cartridge 21 has been installed. On mechanical prevention means 2108 already prevents insertion of ink cartridges not approved by the manufacturer of the printing device are. The electronic and mechanical means of prevention 210, 2107 and 2108 are preferably combined in one structural unit and on the ink cartridge housing wall (on the neck or Back) attached non-releasably (for example by gluing). The Electronic memory chip 210 for storing warm-up data has one serial interface with electrical contacts 2107 for querying data. According to these electronic and mechanical preventive devices 210, 2107 and 2108 is a control and contacting unit 211 for electronic signal conversion and mechanical connection with the ½ Inch ink cartridge provided.

A second electronic memory chip 220 (not shown) is corresponding provided for the second ink cartridge 22, which is basically constructed in the same way as the first ink cartridge 21.

FIG. 3 shows a block diagram of the electronic semiconductor chip 2100, which identifies at least one data memory 2102 of the ink cartridge 21, a sensor 2109 for the head temperature and ink ejection means E1 ... En ... E300 of a head 2101. With the bubble jet principle, the ink ejection means contain heating resistors R1 ... Rn ... R300, whereby one heating resistor is assigned to an ink chamber and is controlled by a negator N1, ..., Nn, ..., N300. Each negator N1, ..., Nn, ..., N300 is on pins for an address input A1, ..., An, ... for a power input P1, ..., Pn, ... and for ground potential G1 , ..., Gn, ... connected and can be selected. The pins for ground potential G1, ..., Gn, ... and those of the power inputs P1, ..., Pn, ... are combined for a preselection to 14 groups each. For example, 20 ink ejection agents E262, E264, ..., En, ..., E298, E300 of a head 2101 are common via the pins P14 and G14 of the fourteenth group and 22 ink ejection agents E86, E88 are connected via the pins P6 and G6 of the sixth group , ..., Em, ..., E126, E128 of head 2101 can be preselected together. The pins for an address input A1 to A7, A9 to A14 and A16, ..., An, ..., A22 are combined to form 20 address inputs A1, ..., An, ..., A22 which contain the 20 ink ejection means E262 , E264, ..., En, ..., E298, E300 of the fourteenth group of the head 2101 individual. The pins for an address input A1, ..., An, ... for the other groups are combined up to a maximum of 22 address inputs A1, ..., An, ..., A22, around the 22 ink ejection means, for example the sixth Group to be able to select individual. This means that with 50 contacts of the 2105 contacting unit, over 300 dots can already be addressed. The memory cells of a read-only memory 2102 (ROM) can also be individually addressed via the 22 address inputs A1, ..., An ..., A22. The word width of the ROM 2102 is 1 bit, which can be queried via the pins R10x, G6, for example to query the type (1 bit), the ink cartridge serial number (8 bit) and possibly other data (13 bit). Each memory cell is constructed similarly to the circuit for an ink ejection agent. It has a negator with FET and a drain resistor. The latter is mask programmed and can be connected in parallel to a reference resistor if pins G14 and G6 are connected. A resistance reference value is queried via contact pin R10x if G14 is selected. Another contact pin S is provided for querying the head temperature sensor. The contacting unit 2105 connected to the head 2101 has a total of 52 contacts (FIG. 2).
FIG. 4 shows a block diagram with a control and contacting unit (pen driver unit) and the electronic control unit of the printing device. The control unit 14 of the printing device has at least one microprocessor 140, a user interface 142, 143, a memory 200, a serial interface 144 and a clock / date module 145. The control unit 14 is, for example, one meter of a franking machine and also contains a secure accounting unit 141 (Secure Accounting Device) for booking frankings. The control unit 14 is connected to the memory 200. The control unit 14 is connected to the contacting unit 2107 of the memory 210 via a serial interface 144 via a contacting unit 2117 of the control and contacting unit 211. The latter is, for example, an E ² PROM or similar non-volatile read / write memory. The control and contacting unit 211 contains a user-specific circuit (ASIC) 2111 and a temperature sensor 2119 for determining the ambient temperature. The inkjet print head temperature from sensor 2109 and an 8-bit ink cartridge serial number can be queried from read-only memory 2102 (ROM) via contacting unit 2115 of a parallel interface of ASIC's 2111 of control and contacting unit 211. The latter supplies the 8-bit ink cartridge serial number to the contact unit 2105 of the parallel interface of the semiconductor chip 2100, which is connected to the contact unit 2115 of the parallel interface of the user-specific circuit ASIC 2111. The data stored in the memories 200, 210, 220 are called up by the microprocessor and the head temperature determined by the sensor 2109 is queried. The user-specific circuit (ASIC) 2111 of the control and contacting unit 211 receives serial signals, which are now supplied by the control unit 14 of the printing device 1 so that they are converted into parallel control signals for the electronic semiconductor chip 2100. A voltage converter (DC / DC) 2112 - controlled by the ASIC 2111 - generates the compressive voltage at the required level.
A second control and contacting unit 221 (not shown) for the second ink cartridge 22 is basically constructed in the same way as the control and contacting unit 211 for the first ink cartridge 21.
Alternatively, a common pressure control unit 20 (not shown) is also possible, which contains a user-specific circuit (ASIC) 2011 and a voltage converter (DC / DC) 2012 and to which two contacting units 211 and 221 can be plugged. The common pressure control unit 20 is controlled by the control unit 14. A possible difference between the two ink cartridges 21 and 22 with respect to the drive pulse energy is then compensated for with the same pulse height by means of a modified pulse duration.

The method provides for warm-up data to be stored under first conditions, for second conditions to be determined and for the associated warm-up data to be determined under current second conditions. The E ² PROM or a comparable non-volatile memory 210, 220 arranged on the ink cartridge 21, 22 is provided for storing warm-up data in a first memory area and the ink cartridge serial number in the second memory area, the latter with the ink cartridge serial number stored in the memory ROM 2102 is identical. For example, the microprocessor 140 uses the ink cartridge serial number from the ROM 2102 to access the first memory area of the memory 200 or 210, 220 with the warm-up data. A manufacturer identification number of the manufacturer supplying the printing device 1 and ink cartridges 21, 22 can be stored in the memories 200 or 210, 220. The manufacturer identification numbers of all ink cartridges 21, 22 are identical. The authorization to use the ink cartridges 21, 22 can be checked by the microprocessor 140 on the basis of the manufacturer identification number, which is stored in a memory area of the memory 200. The shape of the contacts 2107, the type of interface (serial) and mechanical prevention means 2108 additionally limit the possibilities of the user to use the ink cartridges from another manufacturer without authorization. The correctness of all codes or numbers can be checked, for example, by a remote data center. In the unpublished German patent application number 199 58 941, a method for protecting a device from being operated with impermissible consumables and an arrangement for carrying out the method have already been proposed, wherein a code is assigned to the ink cartridge and the authenticity of the ink cartridge is checked on the basis of a stored one Reference code word takes place in a remote data center.
Warm-up data is stored under the first conditions in a manner known per se when the ink cartridge is installed for the first time, while at the same time the authenticity of the consumables (ink cartridge) can be checked in a remote data center using the manufacturer identification number and the 8 bits - Ink cartridge serial number or alternatively based on a code word read from the memory 210, 220 by comparison with a reference code word stored in a remote data center. The code word can also be formed by encrypting serial and identification numbers or is only assigned to the serial number. Communication with the remote data center can then be intercepted but not evaluated in order to generate counterfeit ink cartridges with a real ink cartridge serial number and manufacturer identification number.

With reference to FIG. 5, which shows a temperature / voltage diagram, the determination of warm-up data under the first conditions when the ink cartridge is installed for the first time is now explained. The prerequisite is that the ambient temperature ϑ _U measured by the control and contacting unit 211, 221 (pen driver unit) is in the optimal range and that, after calibration, the head temperature ϑ _K can be measured by a temperature sensor of the printhead. In the case of ½ inch ink jet cartridges, for example 22 temperature values of the printhead are measured after being switched on, each of which corresponds to a predetermined pressure pulse voltage value. Each nozzle is actuated a thousand times with a pulse voltage of ≥ 12 V with a pulse width of approx. 2 µs. The pressure pulse voltage value is gradually reduced before each further measurement. The measured temperature curve is evaluated by looking for the local minimum of the temperature curve. The associated pressure pulse _voltage U _P (ϑ _Kmin ) is multiplied by a factor of 1.3. The resulting optimal pressure pulse voltage value is used for printing and warming up. When warming up, however, the pulse width is reduced to approx. 0.75 µs. The optimal pressure pulse voltage value and the measured voltage temperature curve are stored non-volatile. In the above example, when a new ink cartridge was installed, a temperature / voltage curve for one parameter (ambient temperature gespeichert _U = 20 ° C) was stored in a first memory area using 22 measured values. With a further parameter n _O , the ink cartridge is automatically evaluated as new if no past-related data are known yet. For the optimal pressure pulse _voltage U _Popt are equations: U Popt = 1.3 U P (θ Kmin ) U Popt = F {ϑ U , ϑ Kmin , n O } can be set up, the function F determining the course of the curve. If other conditions prevail the next time the _{device is} switched on (for example ϑ _U = 25 ° C), a new measurement of a temperature / voltage curve can be dispensed with according to the invention, since instead a U _Popt determination based on the temperature / voltage curve by a Data tracking is made.

a) empirisch ermittelte Daten für die optimale Druckimpulsspannung U_Popt bei unterschiedlichen Umgebungstemperaturen ϑ_U bezogen auf erste Bedingungen n_O sind in einer Tabelle 1 gespeichert.

b) Algorithmus zur Berechnung der optimale Druckimpulsspannung U_Popt bei unterschiedlichen Umgebungstemperaturen ϑ_U bezogen auf erste Bedingungen n_o (siehe Gleichung (1)).

There are two basic options for data tracking:

a) empirically determined data for the optimal pressure pulse _voltage U _Popt at different ambient temperatures ϑ _U based on the first conditions n _O are stored in a table 1.

b) Algorithm for calculating the optimal pressure pulse _voltage U _Popt at different ambient temperatures ϑ _U based on the first conditions n _o (see equation (1)).

Table 1 was recorded for a new print head with serial number 256 and corresponds to the diagram shown in Fig. 5. Starting from a maximum value of 12 V, the voltage is gradually reduced. The step size is 0.2 V. The minima ϑ _Kmin have been highlighted in bold.

In the case of empirically determined data and one in between Ambient temperature can not be saved intermediate values for the associated pressure pulse voltage using a normal interpolation calculation determine. The pressure pulse voltage associated with the ambient temperature is multiplied by a factor of 1.3 and results in the optimal one Pressure pulse voltage (highlighted in bold).

For a printhead that is not as good as new, additional conditions must be determined as a combination of parameters that enable past and user-related adaption by generating further tables depending on the parameter n _P , O _user . The second conditions (printhead age, level) are expressed by the past parameter n _P. In the simplest case, there is a second table, since a distinction is only made between new (parameter n _O ) and old (parameter n _P ). The user-related parameter O _user creates a further adaptation for an even quick operational readiness. In the simplest case, there is only a third and fourth table, since only two cases are differentiated normally and more quickly. parameter n _o n _{P no o user} n _P , O _user table 1 2 3 4

FIG. 6 now shows the flow chart for data tracking for warm-up cycles of ink jet print heads. After the start step 100, the identification number ID of the cartridge manufacturer is preferably read by the control unit 14 (step 101) and checked (step 102). If the cartridge manufacturer is permitted, the program branches to step 104. Otherwise, a branch is made back to step 101 via step 103 for submitting an error message. This ensures quality because only cartridges from a certain manufacturer are accepted. In step 104 it is checked whether a new installation of an ink cartridge should take place. Ink cartridges that have already been used and replaced in the meantime can also be used again. For such an ink cartridge that is not as good as new, warm-up data, with parameter n _o, the first condition and possibly a code word are already stored in the memory. The control unit 14 has a security module 141 which is able to form a code (word) by encrypting the serial number and the manufacturer identification number. The code word is stored in the memory 210, 220 of the ink cartridges. If a code word or the parameter n _{O is} stored, no new installation is carried out and the process branches to step 111 in order to carry out a data update for a quick start in subsequent steps. Up to 256 different serial numbers with associated warm-up data and parameters can be stored in a memory 200 of the franking machine. The storage space requirement can be reduced, the more data (code, serial number and associated warm-up data and parameters) are stored in the memory 210, 220 of the ink cartridges themselves.

If a new installation is to be carried out, the serial number is first read in step 105 and, if necessary, a code is generated which is at least assigned to the serial number. After reading the serial number in step 105, a branch is made to step 106 in order to trigger the automatic transmission of the code or the serial number to the teleportodata center TDC. The transmission can also take place later, for example in the case of communication for the purpose of recharging the credit. The consumables used are recorded in the TDC and the serial number code is checked. The ink cartridge of the particular manufacturer with the read serial number must actually have been delivered to the user. Otherwise, measures can be taken to protect against piracy products. In the case of a new installation, the ambient temperature ϑ _{U is} measured in step 107 and a curve is determined for the head temperature ϑ _K = f {U _P }, the latter being a function of the pressure pulse voltage U _P applied to the heating elements. In the range 12 V ≥ U ... _P ≥ U _Pmin a minimum the head temperature θ is _Kmin. In step 108, the pressure pulse _voltage U _P (ϑ _Kmin ) is determined, which is assigned to the minimum. The optimum pressure pulse voltage is then determined according to equation (1) above and stored in the first memory area of a memory 200 or 210, 220. In step 109, the serial number or code and first conditions n _{o are} stored in the second memory area of the memory 200 or 210, 220. In the subsequent step 110, a first table for the optimal pressure pulse voltage is selected as a function of the parameters or according to the equation ( 2) generated.
From step 110, a branch is made via step 104 to step 111, where a query is started as to whether second conditions have been newly entered. In the case of a new installation, this is not the case and the process branches to step 113, where a query is started as to whether second conditions have been saved. If a parameter O _{user has been} entered and stored in a _user- related manner at a previous point in time and is to be made ready for operation quickly, a branch is made to step 114. In the case of a new installation, this is usually not the case and the process branches to step 116, where warm-up data associated with the serial number of the ink cartridge are stored. In step 117, preheating with pulses of duration t = 0.75 μs and height U _{Popt can thus be} carried out. The head temperature measured repeatedly in step 118 is monitored (steps 119, 120). If it is determined in step 119 that a minimum of the optimum head temperature range is not undershot, a check is made in step 120 as to whether a maximum of the optimal head temperature range is not exceeded. If the head temperature is within the optimal head temperature range, then the end (step 122) is reached. If, however, the head temperature is below the optimal head temperature range, then ϑ _K > ϑ _Koptmin does not _apply and the _{process branches} back to step 117 for preheating. The warming-up impulses lead to a stepped head temperature. Otherwise an error message is issued (in step 121) if the check in step 120 shows that a maximum of the optimal head temperature range is exceeded (then _{dann K} <ϑ _Koptmax does not _apply ). The reduction in warm-up cycles is noticeable with a used ink cartridge. The invention has the advantage that in the case of ink cartridges which are not as good as new, the warm-up cycles with ink splashes of a new installation can be avoided. If a method for data tracking is used for the warm-up _{cycles, the} warm-up data U _Popt and t = 0.75 μs stored in step 116 guarantee a warm-up of the print head of an ink cartridge which is not as good as new in less than half the time, ie within a time of < 30 s.
In the case of a used ink cartridge, the query in step 111 can show that a second condition should be re-entered. For example, a user-related parameter O _user can be entered by the user himself using the keyboard. Alternatively, the Teleporto data center enters a parameter O _user in connection with a credit recharge and after checking the serial number of the ink cartridge, which influences the warm-up time.

a) die optimalen Aufwärmdaten U_Popt (ϑ_U) werden aus einer gespeicherten Tabelle mit gemessenen und teilweise empirisch ermittelten Daten entnommen. Dann werden letztere und die 2.Bedingungen in eine Gleichung eingegeben : UPopt3 = F3{ UPopt (ϑU), ϑK, nP, Ouser} und die Impulsdauer beträgt t = 0,75 µs
oder die Gleichung lautet: UPopt4 = F4{UPopt (ϑU), ϑK, nP} und die Impulsdauer liegt im Bereich 1,9 µs > t(O_user) > 0,75 µs und wird entsprechend dem Kundenwunsch ausgewählt.

b) die optimalen Aufwärmdaten werden rechnerisch nach einem Algorithmus für mindestens zwei Tabellen generiert: U_Popt1 = F₁{(ϑ_U), ϑ_K}, U_Popt2 = F₂{(ϑ_U), ϑ_K}. Für mindestens einen Parameter np oder O_user steht nun eine der Tabellen zur Verfügung, zum Beispiel Tabelle 2, aus der U_Popt2 für ein Schnellaufwärmen entnommen werden kann.

If the ink cartridge is a piracy product, then the warm-up time can be extended at least. After all, only a quality product, the characteristics of which are known, should allow a quick warm-up.
In another case, a parameter for a quick warm-up is entered by the teleporto data center TDC based on a customer request. The parameter O _user stands for a user-related reduction in the warm-up time of the printhead. The warm-up data stored in step 116 deviate in terms of the pulse height from the value of the optimal pressure pulse _voltage U _Popt . At a lower pulse height, the life of the printhead of the ink cartridge and also the warm-up time of the printhead are extended. With a higher pulse height, the service life of the print head of the ink cartridge and also the warm-up time of the print head are reduced. This also applies to the pulse duration. In addition to the pulse height, the pulse duration can also be changed. It is provided in a variant that the parameter O _user allows a quick start by changing the pulse duration according to the customer's request.
The parameters np for warm-up data of the used ink cartridge are known, that is to say they can be queried or stored, and the process branches from step 112 to step 113 to step 114. Now at least one measurement of the ambient temperature ϑ _U and possibly the current head temperature ϑ _{K is carried out} . If all required parameters are known, step 115 is reached. A corresponding table can either be selected here or the optimal warm-up data are generated mathematically using an algorithm. It is possible to use a mixed procedure with select and generate:

a) the optimal warm-up data U _Popt (ϑ _U ) are taken from a stored table with measured and partly empirically determined data. Then the latter and the 2nd conditions are entered into an equation: U Popt3 = F 3 {U Popt (θ U ), ϑ K , n P , O user } and the pulse duration is t = 0.75 µs
or the equation is: U Popt4 = F 4 {U Popt (θ U ), ϑ K , n P } and the pulse duration is in the range of 1.9 µs> t (O _user )> 0.75 µs and is selected according to customer requirements.

b) the optimal warm-up data are generated mathematically according to an algorithm for at least two tables: U _Popt1 = F ₁ {(ϑ _U ), ϑ _K }, U _Popt2 = F ₂ {(ϑ _U ), ϑ _K }. One of the tables is now available for at least one parameter np or O _user , for example Table 2, from which U _Popt2 can be taken for a quick _warm-up .

The parameter n _P relates to data related to the past, such as the amount of ink remaining, because the fill level, the number of frankings or the operating age since the first installation or the usage date up to which the ink should be used. This means that a number of tables have to be generated or set up with empirically determined data. A table can then be selected from the number. The current second conditions are described by the ambient temperature ϑ _U , the ink print head temperature ϑ _K and parameter n _P , O _user , the parameter n _P depending on the use of the ink cartridge and the parameter O _user depending on the selection made by the user for one shortened warm-up cycle can be called by the control unit 14. When two ink cartridges are used, these are controlled as a result of different temperature or past data tracking with different warm-up data.
The invention is not limited to the present embodiments. Rather, a number of possibilities for generating or selecting a table - within the scope of the claims - are conceivable before step 116 is then reached again in order to store the optimal warm-up data determined, assigned to a code or to the serial number of the ink cartridge.

Obviously, other other embodiments of the invention can be developed or used, which have the same basic idea of Invention are to be embraced on the basis of the appended claims.

Claims (20)

Arrangement for data tracking for warm-up cycles of inkjet printheads, comprising a unit (211, 221) for warming up, measuring temperature and controlling an inkjet printhead (2101, 2201) and a control unit (14) for controlling the unit (211, 221) and a memory for storing of warm-up data of the ink jet print head (2101, 2201), characterized in that the memory (200, 210, 220) is rewritable and in addition to a first memory area for storing warm-up data of the ink jet print head (2101, 2201), a second memory area for storing predetermined conditions The temperature-related and past and / or user-related, and that the aforementioned control unit (14) is programmed, perform at least one measurement of the ambient temperature with a sensor (2119, 2219), as a function of this and as a function of the predetermined conditions, to determine warm-up data for a warm-up cycle in accordance with the temperature-related and the past and / or user-related conditions when driving the ink jet print head (2101, 2201) for a quick start. Arrangement according to claim 1, characterized in that a memory (210, 220) is formed for storing identification data and the further predetermined conditions and is arranged on an ink cartridge (21, 22) that a memory (14) arranged in the control unit (14) 200) is configured to store warm-up data associated with the identification data, and that the control unit (14) is programmed to access the memory (200) of the control unit (14) in order to carry out the data tracking. Arrangement according to claim 1, characterized in that a memory (210, 220) is provided, the first memory area for storing warm-up data and the second memory area for storing identification data of an ink cartridge and other predetermined conditions, that the memory on a Ink cartridge (21, 22) arranged and the control unit (14) is programmed to query the ink cartridge serial number from the ink jet print head (2101, 2201) and to generate identification data, as well as depending on further predetermined conditions associated with the identification data in the second Memory area can be stored, to access the first memory area of the memory (210, 220) in order to carry out the data tracking. Arrangement according to claims 1 to 3, characterized in that a sensor (2109, 2209) is provided for measuring the temperature of the ink jet print head (2101, 2201) and is designed to be queried by the control unit (14) via unit (211, 221). Arrangement according to claims 2 and 3, characterized in that the identification data include at least one ink cartridge serial number or a code word which is assigned to an ink cartridge serial number. Arrangement according to claims 2 and 3, characterized in that the identification data include at least one manufacturer identification number which is stored in the memory (210, 220). Arrangement according to claim 5, characterized in that a security module (141) is provided in the control unit (14) to form and store the code word by encrypting the serial number and manufacturer identification number. Arrangement according to claim 1, characterized in that a user interface (142, 143) is provided in order to enter a user request for a quick start or a parameter for a quick start, the user request being transmitted to a teleportodata center which can enter the parameter for a quick start that one of the memories (200, 210, 220) is designed to store the parameter, so that one of the conditions for data tracking includes user-related data. Arrangement according to claims 1 and 2, characterized in that a memory area of the memory (200, 210, 220) and that a date / clock module (145) are provided in the control unit (14) that in the memory (200) of the control unit (14) or in the memory (210, 220) of the ink cartridge (21, 22) historical data about the operation of the ink cartridge (21, 22) are stored, so that one of the conditions for data tracking includes historical data. Method for data tracking for warm-up cycles of inkjet printheads, by means of a control unit (14), which carries out the warm-up cycles before the operation of inkjet printheads to determine the optimum print pulse voltage, characterized in that storage of warm-up data and data of a first condition before a new installation of an ink cartridge occurs After the first use, parameter data for second conditions are determined for a quick start with repeated use and that the associated warm-up data is determined in a mathematical or tabular manner under current second temperature-related and past and / or user-related conditions and used for at least one warm-up cycle. Method according to claim 10, characterized in that the warm-up data under current second conditions is determined according to an algorithm by means of the control unit (14) and stored in the memory (200, 210, 220). Method according to claim 10, characterized in that the warm-up data under current second conditions are determined by means of the control unit (14) from a dependency stored in a memory (200, 210, 220). Method according to claim 10, characterized in that a parameter n _{P is} called up depending on the use of the ink cartridge and that the current second conditions include temperature-related and past-related data tracking by means of the control unit (14) in accordance with that in the memory (200, 210, 220) Allow stored warm-up data to be performed. Method according to Claim 10, characterized in that a parameter O _{user is called up} as a function of the selection made by the user and that the current second conditions are temperature-related and user-related data tracking by means of the control unit (14) corresponding to that in the memory (200, 210, 220) allow stored warm-up data to be performed. Method according to claims 10 to 14, characterized in that the pulse height U _{Popt is modified} during data _tracking and the pulse duration t (O _user ) of the warm-up data is constant and less than the pulse duration during printing. Method according to claims 10 to 13, characterized in that the pulse height U _{Popt is modified} for the temperature- _related and past-related data tracking and that the pulse duration t (O _user ) of the warm-up data is modified with the parameter O _user for a _user- related data tracking. A method according to claim 10, characterized in that before each use of an ink cartridge, the control unit (14) determines the existence of the manufacturer identification number of an allowed cartridge manufacturer and that with warm-up data already stored, with the first condition stored with parameter _no or with A stored code word is followed by data update for a quick start without reinstallation. Method according to claim 17, characterized in that the current second conditions are described by the ambient temperature ϑ _U , the ink print head temperature ϑ _K and parameters n _P , O _user , the parameter n _P depending on the use of the ink cartridge and the parameters O _user depending on the selection made by the user for a shortened warm-up cycle can be called up by the control unit (14). Method according to claim 18, characterized in that two ink cartridges are activated as a result of different temperature or past-related data tracking with different warm-up data U _P1opt , t ₁ (O _user ) and U _P2opt , t ₂ (O _user ). Method according to claim 19, characterized in that with the same pulse height U _P1opt = U _P2opt a difference between the ink cartridges (21, 22) with regard to the control pulse energy is compensated for by a modified pulse duration t ₁ (O _user ), t ₂ (O _user ) ,

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