EP0593813B1 - Electrographic printing or copying device with a thermal fixing station and with an arrangement for programme-controlled setting of operating parameters - Google Patents

Description

The invention relates to an electrographic printing or copying device with a heat-setting station and an arrangement for program-controlled setting of operating parameters of the fixing station.

Such a device is known for example from the abstract of JP-A-2062574.

For thermal printing fixing of toner images on a recording medium mostly made of paper, heat-fixing devices are used in electrographic printing or copying machines which work according to the electrophotographic, ionographic or magnetographic principle, which have a preheating saddle with a downstream fixing zone comprising a heated fixing roller and a pressure roller.

Such heat fixing devices are e.g. known from US-A-4 147 922 or JP Abstract Vol. 13, No. 120, March 24, 1989 (JP-A-63-292177).

It has now been found that the print quality of such devices depends crucially on the fixing quality that can be achieved with the fixing station. The fusing quality, in turn, depends on the various operating parameters of the fusing station. These are e.g. the fixing energy supplied to the recording medium and the negative pressure with which the recording medium is braked and pressed against the preheating caliper.

The fixing energy supplied is of particular importance. It must not be too big and not too fast are fed to the record carrier, because otherwise the record carrier is stressed too much and permanent deformations interfere with the paper postprocessing. On the other hand, the fixing energy must be so high that the loose toner images are securely connected to the recording medium. It is therefore beneficial to regulate the fixing energy to be supplied.

It has now been found that the fixing quality depends crucially on the characteristics of the recording medium. These characteristics are in particular the paper basis weight and other data describing the structure and properties of the paper or other recording media, e.g. Variety labeling data.

The fusing quality depends particularly on the paper basis weight if a very large paper basis weight spectrum has to be processed, e.g. in a range from 60 gr / qm to 160 gr / qm. In general, the larger the paper basis weight, the worse the fixing quality becomes with otherwise the same paper parameters.

In order to achieve a good connection of the toner image to the paper fiber structure, the paper must be heated to a temperature in the range of the melting temperature of the toner images, which is in a range of approximately 90 to 110 °, before it passes through the fixing gap of the fixing station. The preheating of the paper is achieved when using paper webs by pulling the paper web over a heated preheating saddle. The so reaching paper temperature at the outlet of the saddle is thus dependent on the temperature of the heated saddle and the time during which the paper is exposed to the saddle temperature.

If paper is printed which has a larger paper basis weight and thus also a larger volume and thus more water, the melting temperature can essentially only be achieved by increasing the saddle temperature with otherwise the same geometrical dimensions of the saddle.

In a fixing gap downstream of the saddle in the paper running direction between a fixing roller and a pressure roller, the toner image on the preheated paper web is firmly connected to the paper surface structure of the paper web under pressure and heat. In the fixing nip, the heat flows from the hotter fixing roller at a temperature of about 180 to 220 ° to the toner image, which melts in the border area to the paper surface and from there to the preheated paper web. Preheating the paper web is necessary because otherwise too much heat would be removed from the fixing gap by the paper web.

If the paper has a larger paper basis weight and thus a larger mass, more heat must flow in order to achieve a constant contact temperature between the toner image and the paper. This in turn requires an increase in the fuser roll temperature.

This means that, in order to achieve a constant fixing quality, it is favorable to adjust the temperature of the preheating saddle, e.g. can consist of a preheating saddle and an actual heating saddle and adjust the fixing roller depending on the paper basis weight.

If a paper web is heated, components of substances necessary for the production of the paper, such as water, glue, resins etc., escape from the paper. The result is that the volume of the paper changes and the paper fiber shrinks more or less, what a Reduction in width and length of the paper web results.

If the heat of the paper web is not applied evenly from both sides, there is a different shrinkage between the front and back of the paper web, which deforms the paper web and possibly results in a curvature.

Such deformations of the record carrier are extremely disruptive in the subsequent post-processing of the record carrier. This applies in particular to continuous paper printers in which forms are cut from the continuous web in cutting machines and read, sorted and enveloped in further processing machines. Depending on the quality of the post-processing machine used, the paper must be correspondingly flat, since otherwise paper run problems will occur.

Continuous paper printers in particular must be able to process an extremely wide range of papers with a wide variety of paper properties, e.g. with a paper basis weight of 50 gr / sqm to 160 gr / sqm, coated and uncoated papers, recycled papers, plastic-coated papers, long-fiber and short-fiber papers, etc. In addition, paper types with new properties come onto the market every year that are processed by the printers without hardware changes Need to become.

In the case of data printers which work at very high printing speeds, in order to achieve an acceptable fixing quality, the paper must be preheated before the fixing gap is reached. The paper web is usually preheated via the back of the paper web by running it over a heated, temperature-controlled preheating saddle with good thermal contact. Then the actual one takes place Fixing the toner images on the paper web in the fixing nip by means of pressure and heat, the heat starting from the fixing roller being fed directly to the toner image.

Is the heat input, i.e. the supply of the fixing energy from the back and from the front of the paper web is not the same size, so there is the aforementioned deformation.

Because of the wide variety of paper properties, there is no uniform setting of the saddle and fixing roller temperatures for all types of paper in order to produce a uniform heat flow between the front and back of the paper web. In addition, since these paper properties, which determine the deformation and curvature of the paper web under the influence of temperature, cannot be detected by means of sensors, it is expedient to make the amount of heat input and thus the fixing energy to the front and rear of the paper web adjustable. This setting must be able to be made without a deterioration in the fixing quality.

The aim of the invention is therefore to provide an electrographic printing or copying device with a heat-setting station and an arrangement for program-controlled setting of operating parameters of the fixing station, which enables the user to easily set the operating parameters.

Another object of the invention is to design the setting so that the fixing qualities do not deteriorate as a result of the setting process.

These goals are achieved in accordance with the features of the first claim.

Advantageous embodiments of the invention are characterized in the dependent claims.

A constant fixing quality is guaranteed by a program-controlled setting of the operating parameters depending on the characteristics of the recording medium.

This setting is simplified for the user in that he can enter the characteristic data and select fixing levels via a control panel.

The coupling of the setting parameters of the fixing station, such as the temperature of the preheating and heating saddle and fixing rollers via fixing steps, enables easy selection and setting without the fixing quality deteriorating by entering an unfavorable setting parameter combination.

The input of recording medium-specific characteristic data and the selection of the corresponding fixing levels is made considerably easier by a menu control. The operator is presented on the control panel with a menu of the various adjustable fixing levels and the paper data to be entered, in particular the weight per unit area.

In an advantageous embodiment of the invention, it is possible to call up program sequence menus, a combination of individual menus being assigned to a program sequence menu. This makes it possible to assign a special menu combination to each printer job for a large number of printer jobs to be processed in succession. For each printer job, the corresponding characteristics of the paper to be processed and the fixing levels to be set are automatically taken into account.

In addition to the paper basis weight, it is also possible to take into account the vacuum operating parameter at the fuser. With a corresponding change in the paper basis weight, it can be expedient to adapt the vacuum on the preheating caliper and in the paper brake analogously. This adaptation is advantageously carried out in accordance with the setting of the operating parameter "fixing energy". This setting can be coupled with the setting of the fixing energy or can also take place independently of this only as a function of the entered characteristic data of the paper.

An electrophotographic printing device for printing on continuous paper contains a heat fixing device shown schematically in FIG. 1. The heat fixing device is designed as a thermal pressure fixing device. It contains a heating roller 11 which is heated by radiators 10 and a pressure roller 12 which can be pivoted to and from the heating roller 11 by an electric motor. The heating roller consists of an aluminum cylinder with a heat-resistant coating arranged thereon, the pressure roller likewise consists of an aluminum cylinder with a silicone coating. The heating roller 11 is driven by an electric motor. The heating roller 11 is assigned an oiling device 13 for applying separating oil to the heating roller. A heated preheating saddle 15 with associated vacuum brake 16 is arranged upstream of the rollers in the direction of recording medium transport, which serves to preheat a recording medium 17 designed as continuous paper and to supply it to the actual fixing gap between the rollers 11 and 12 in the preheated state. Braked by the vacuum brake 16 and driven by the rollers, the recording medium 17 is guided tightly over the preheating caliper 15. A loose toner image on the recording medium is preheated on the preheating saddle 15 and fixed between the rollers 11 and 12 by heat and pressure.

A cooling device 18 arranged downstream of the rollers 11 and 12 in the paper running direction ensures cooling of the heated paper. For this purpose, the cooling device 18 contains a cooling surface 19 provided with openings, which is swept by the recording medium 17, with cold air supplied via an air supply channel 20 flowing out of the openings and a cooling air cushion being created under the recording medium 17. At the same time, air is blown onto the concrete side of the recording medium via an opposite profile.

In the heat-fixing device described, the continuous paper 17 is preheated via a preheating saddle 15 which consists of two heated saddles connected in series, namely a stationary preheating saddle 21 and a heating saddle 23 which can be pivoted about a pivot point 22. The preheating saddle 21 and heating saddle 23 form two separate heating zones when viewed in the direction of paper travel . The entire preheating section has a length of approximately 500 to 700 mm. The paper 17 slides during preheating with its toner-free side on sliding surfaces 24 of the preheating saddle 21 or heating saddle 23.

In order to make good contact between the saddles and the paper and thus to keep the temperature difference small, the sliding surfaces or the saddles are curved with a curvature radius which in the example shown is 700 mm. Due to the curvature of the sliding surfaces in connection with the train through the rollers 11 and 12 and the braking by the vacuum brake 16, a force component acts over the entire length of the saddle, which presses the paper 17 against the sliding surfaces 24; thereby promoted. As can also be seen from FIG. 2, the saddles 21 and 23 have elongated depressions 25 which extend transversely to the paper running direction and extend over the entire width of the saddles. They are connected to a vacuum channel 27 (FIG. 1) by lateral bores 26. The vacuum channel runs below the saddles and is equipped with a vacuum generating device, e.g. a pump. Due to the negative pressure, the recording medium (paper) is sucked onto the sliding surfaces 24 of the saddles and the water vapor released by the preheating is sucked out.

The saddles 21 and 23 are heated by electrical resistance elements in the form of interchangeably arranged ones Heating cartridges 28. To accommodate the heating cartridges 28, the saddles 21 and 23 have through bores 29. These holes enable the replacement of each individual heating cartridge 28 in the event of a defect. In addition, the saddles 21 and 23 can thus be produced inexpensively from an extruded aluminum profile.

By arranging the cartridges in the saddles, each saddle 21 or 23 is divided into three heating zones 30/1, 30/2 and 30/3 transversely to the direction of paper travel (FIG. 2). These transverse heating zones 30/1 to 30/3 are used to adapt the saddles to different recording medium widths. The first heating zone 30/1 is delimited on one side by the fixed paper running edge 31. This heating zone 30/1 is as wide as the minimum width of the recording medium. The remaining area of the saddles up to the maximum recording medium width is divided into the equally wide heating zones 30/2 and 30/3. Each of the transverse heating zones 30/1 to 30/3 has a temperature sensor 32/1 to 32/3 for regulating the heating zones. It is located approximately in the middle of the respective heating zones across the paper running direction. When viewed in the paper travel direction, the sensor position is selected so that the same temperature can be controlled both in the standby state of the printing device (standby) and in the printing mode itself. This simplifies the temperature control. The control temperature and the position of the sensors 32/1 to 32/3 are selected so that the paper temperature at the end of the saddle is just as high during the starting phase as during a longer printing phase. The area from the middle to the last third of the saddles has proven to be a favorable sensor position.

The heating zones 30/1 to 30/3 are generated by the arrangement of the heating cartridges 28 in the bores 29.

This is as follows:

A cartridge for the two outer heating zones 30/1 and 30/3 is inserted into the first hole of a saddle in the direction of paper travel. A heating cartridge 29 for the middle zone 30/2 is inserted into the second hole. The third hole is equipped like the first, etc. There are therefore six heating cartridges 28 in each heating zone 30/1 to 30/3.

The surface temperature of the saddles and thus the temperature of the recording medium are controlled with the aid of a control arrangement as shown in FIG. 3.

The control arrangement contains an actuator 33, for example in the form of individual relays for coupling the heating cartridges 28 to a power supply unit 34. The control element 35 is connected downstream of the control element 35 with the heating cartridges 28. The actual temperature is detected by the temperature sensors 32/1 to 32/3 and converted into an electrical control signal by the sensors and amplified in a subsequent amplifier 37. A microprocessor-controlled control device 39 coupled to the amplifier 37 compares the actual temperature with a predefinable target temperature TS and regulates the target temperature as a function of the control deviation. For this purpose, the control device contains an analog-digital converter 40 with the associated program-controlled two-point controller 41. The microprocessor-controlled control arrangement 39 is also coupled to the controller 42 of the printing device, which has an arrangement described below for program-controlled setting of operating parameters of the fuser station. The control arrangement shown in FIG. 3 can be part of the program-controlled setting arrangement for the operating parameters of the fixing station. It is used specifically to regulate the Temperature at the preheating saddle. It is regulated to a target temperature TS, which is referred to below as a control target value. The setpoint temperature at the preheating saddle is the temperature at which the paper leaves the preheating saddle or the entry temperature of the paper into the fixing nip between fixing roller 11 and pressure roller 12. An additional low-voltage power supply unit 44, which is coupled to the actual power supply unit 34, provides the power supply the device control and thus the microprocessor-controlled control device 39.

To regulate to the predetermined setpoint, in this case the outlet temperature at the preheating saddle, the microprocessor-controlled control arrangement 39 switches the heating cartridges on to the phases of the three-phase network of the power supply unit 34 via the actuator 33. After reaching the target temperature, they are separated from the mains again via the actuator 33. After starting the printing operation, depending on the paper temperature, the paper basis weight, the printing speed and the surface quality of the paper and the width of the paper, heat is removed from the preheating saddle 15 via the paper. This influence of disturbance is symbolically represented in the control circuit of FIG. 3 as disturbance SG. The actual temperature resulting depending on the deduction of the disturbance variable is detected by the temperature sensors 32/1 to 32/3 and supplied to the microprocessor-controlled control arrangement 39 in the form of electrical signals. This activates the actuator 33 in a corresponding manner until the predetermined target temperature is reached again.

As already explained, the control arrangement of FIG. 3 for regulating the temperature on the preheating saddle and on the heating saddle of the fixing station is part of an arrangement for program-controlled setting of operating parameters of the fixing station, as shown in FIG.

In the exemplary embodiment shown, the operating parameters of the fusing station are the fusing energy which is fed to the recording medium during the fusing process via the preheating caliper 15 and the fusing roller 11, and the negative pressure in the area of the paper brake 16 and the preheating caliper 15. This negative pressure in the paper brake 16 and in the negative pressure duct 27 can be adjusted via a vacuum generating device in the form of a blower with associated control valve. The negative pressure is detected by means of corresponding commercially available negative pressure sensors.

For reasons of clarity, in the arrangement shown in FIG. 4 for the program-controlled setting of the operating parameters “fixing energy” and “negative pressure” of the fixing station, several functional units, some of which are explained later, are combined to form functional blocks. These are the control panel 43, the controller 42, an additional input arrangement 45 in the form of a personal computer PC for variable input of setting parameters assigned to the units of the fixing station, the converter block 46, the vacuum in the vacuum brake 16 and in the vacuum channel 27 and the corresponding sensors The temperature at the fixing roller 11, preheating saddle 21 and heating saddle 23 is detected and converted into corresponding electrical signals for the controller 42, as well as a power block 47 which actuates the heating elements in the fixing roller, preheating saddle and heating saddle, or the underpressure in the paper brake and the underpressure channel via the underpressure generator Institution.

The structure and function of this arrangement will now be described in more detail below.

The arrangements shown schematically in FIGS. 4, 6 and 7 are used for program-controlled setting of the operating parameters of the fixing station. These are, for example the fixing energy transferred to the recording medium and the negative pressure in the paper brake 16 and on the preheating caliper 15, but also operating parameters such as printing speed, printing operation in general, standby mode etc. The setting of the operating parameter "fixing energy" takes place in fixing stages, with each fixing stage having a specific combination of setting parameters on units of the fixing station, namely temperature on the preheating saddle 21, temperature on the heating saddle 23 and temperature on the fixing roller 11 are assigned. Further setting parameters are, for example, the electrical control values for determining the negative pressure via the negative pressure generating device. These setting parameters are assigned control setpoints as a function of characteristic data specific to the recording medium, such as paper basis weight, paper type or other data characterizing the structure of the recording medium. These control setpoints are, for example, calculated setpoints for temperature and vacuum, via which a control arrangement (for example FIG. 6 in the case of temperature control of the preheating saddle 15) then regulates the operating parameters “fixing energy” and “vacuum”.

In order to be able to determine these control setpoints, on the one hand the characteristic data specific to the recording medium must be recorded and supplied to the arrangement in the form of electrical signals, and on the other hand a separate selection of the fixing stages itself is provided.

• a) Manuelle Eingabe des Papierflächengewichtes: Am Bedienfeld 43 kann eine Bedienfeldtastatur 55 (Fig. 6) vorgesehen sein, über die das Papierflächengewicht alphanumerisch eingegeben wird. Das Papierflächengewicht ist in der Regel auf der Aufzeichnungsträgerverpackung aufgedruckt.
• b) Halbautomatische Eingabe des Papierflächengewichtes: Das Bedienfeld 43 kann mit einem Codelesestift 56 (Fig. 6) gekoppelt sein, über den die Bedienperson einen auf der Verpackung des Aufzeichnungsträgers aufgedruckten Barcode erfaßt und auf diese Weise die erforderliche Information eingibt.
• c) Automatische Eingabe des Papierflächengewichtes:
  • c1) Ist beispielsweise am Boden der Verpackung des Aufzeichnungsträgers ein Barcode aufgedruckt, so kann im Bereich einer Aufnahmeplattform für den Aufzeichnungsträger im Drucker eine automatische Barcode oder OCR-Leseeinrichtung 56 (Fig. 6) angeordnet sein, die die auf der Verpackung des Aufzeichnungsträgers aufgedruckten Daten automatisch erfaßt.
  • c2) Die Papierdicke ist proportional zum Papierflächengewicht. Deshalb ist es möglich, durch Erfassung der Papierdicke das Papierflächengewicht zu bestimmen. Das Bedienfeld 43 bzw. die Anordnung kann deswegen mit einer Einrichtung 57 (Fig. 6) verbunden sein, mit der es möglich ist, die Papierdicke zu erfassen. Diese Einrichtung kann z.B. aus einer Meßeinrichtung bestehen, die optisch mechanisch oder kapazitiv die Papierdicke erfaßt. Derartige Meßeinrichtungen zur Erfassung der Materialstärke sind in der Meßtechnik bekannt. Sie kann z.B. aus zwei Fühlelementen bestehen, zwischen denen das Papier angeordnet wird, wobei eine dickenabhängige Wegänderung der Meßstrecke induktiv, kapazitiv oder über Dehnungsmeßstreifen erfaßt wird. Eine derartige, die Papierdicke erfassende Einrichtung kann im Papiereinlaufbereich der Druckeinrichtung vorgesehen sein. Sie ist mit dem Bedienfeld 43 oder mit der Anordnung unmittelbar gekoppelt.

A key data carrier-specific characteristic date is in particular the paper basis weight. This can be entered and entered in the following way:

• a) Manual input of the paper basis weight: A control panel keyboard 55 (FIG. 6) can be provided on the control panel 43, via which the paper basis weight is entered alphanumerically. The paper basis weight is in usually printed on the recording medium packaging.
• b) Semi-automatic input of the paper basis weight: The control panel 43 can be coupled to a code reading pen 56 (FIG. 6), via which the operator detects a bar code printed on the packaging of the recording medium and in this way enters the required information.
• c) Automatic entry of the paper basis weight:
  • c1) If, for example, a barcode is printed on the bottom of the packaging of the recording medium, an automatic barcode or OCR reading device 56 (FIG. 6) can be arranged in the area of a recording platform for the recording medium, which reads the data printed on the packaging of the recording medium automatically recorded.
  • c2) The paper thickness is proportional to the paper basis weight. It is therefore possible to determine the paper basis weight by recording the paper thickness. The control panel 43 or the arrangement can therefore be connected to a device 57 (FIG. 6) with which it is possible to detect the paper thickness. This device can consist, for example, of a measuring device which detects the paper thickness optically mechanically or capacitively. Such measuring devices for detecting the material thickness are known in measuring technology. It can consist, for example, of two sensing elements between which the paper is arranged, a change in the path of the measuring path depending on the thickness being detected inductively, capacitively or via strain gauges. Such a device that detects the paper thickness can be provided in the paper inlet area of the printing device. It is directly coupled to the control panel 43 or to the arrangement.

The fixing energy to be supplied to the recording medium depends on the one hand on the characteristic data specific to the recording medium, in particular the paper basis weight, which can be automatically recorded or entered. On the other hand, the amount of heat input, i.e. the fixing energy to the front and back of the paper web can be easily selected for the user without the fixing quality suffering because paper properties which determine the curvature of the paper web under the influence of temperature cannot be detected by sensors.

Is e.g. As a result of the paper properties, in order to avoid such deformations, a greater heat flow from the back of the paper web is required, the saddle temperatures are increased and at the same time the fixing roller temperature is reduced. If a greater heat flow from the front of the paper web is required, the saddle temperatures are reduced and at the same time the fixing roller temperature is increased.

The operator is offered a control panel menu with several preprogrammed temperature combinations, the fixing levels, from the control panel 43, from which he can select specific fixing levels in order to achieve a minimum of paper curvature. The setting parameter combination and thus the setting temperature on the preheating saddle, heating saddle and fixing roller is chosen so that the fixing quality as such is not influenced, but rather that there is essentially an influence on the type of supply of the fixing energy to the recording medium. This prevents a choice of the setting parameters, in this case the temperatures on the preheating saddle and the fixing roller, from having a warp-compensating effect, but from worsening the fixing quality overall.

Should it be necessary due to extreme types of paper, in addition to the existing and illustrated fusing levels, further fusing levels, i.e. To provide temperature combination levels, it is possible to additionally enter these in the user menu via the additional input arrangement 45 using a PC or also via the control panel keyboard in a corresponding MENU level.

The fixing levels are entered in the control panel 43 by calling up a "fixing levels" menu. For this purpose, the control panel 43 contains a known microprocessor-controlled arrangement for operator guidance in the form of menus. The input is then made by selecting from fixing levels, which are identified by "min", "low", "normal", "high" and "max". As can be seen from FIG. 5, the setting parameters “temperature” on preheating saddle 21, heating saddle 23 and fixing roller 11 are thereby determined and determined with their temperature values. For example, the setting level "normal" is assigned a setting parameter combination with associated temperature combinations of 220 ° for the fixing roller, 100 ° for the heating saddle and 60 ° for the preheating saddle. The other assignments can be found in the table in FIG. 5.

The arrangement shown in FIG. 6 is provided in order to determine the control setpoints for the units of the fixing station on the basis of the characteristic data specific to the recording medium and the fixing levels, and thus to control the operating parameters such as fixing energy and vacuum. It contains an evaluation arrangement 48 assigned to the controller 42 with a memory field 49, a computing unit 50 and working memory 51/1, 51/2. The memory field 49 has memory cell combinations which can be called up via the control panel 43 and are designated by "min", "low", "normal", "high", "max" and "variable" in accordance with the number of fixation levels which can be selected. In which In the exemplary embodiment shown, three fixing cells 49/1, 49/2 and 49/3 are assigned to each fixing stage, in accordance with the number of setting parameters, in this case the temperature on the preheating saddle, heating saddle and fixing roller. This assignment is not fixed, it can vary depending on the menu called or the desired combination of setting parameters, the assignment being program-controlled via the control panel 43 in connection with the evaluation arrangement 48. In the exemplary embodiment shown, the storage cell combination "normal" in the storage cell 49/1 contains a value characterizing the fixing roller temperature 220 °, the storage cell 49/2 a value characterizing the heating saddle temperature of 100 ° and the storage cell 49/3 a characterizing the preheating saddle temperature of 60 ° Value. The memory cells of the other memory cell combinations "min", "low", max "," variable "are assigned corresponding data that can be seen in Figure 5. The memory cell combination" variable "is used for the assignment of additional setting parameter data via the additional input arrangement 45 coupled to the evaluation arrangement 48 with a PC or via the control panel keyboard via appropriate MENU levels.

Furthermore, the memory field 49 contains memory cell combinations marked P1 to P3, which are assigned the setting parameters assigned to the recording medium-specific characteristic data. In the exemplary embodiment shown, these are the paper weight and the negative pressure. Each of the memory cell combinations P1 to P3 is assigned two memory cells 49/4 and 49/5, which are used to hold data characterizing the setting parameters "paper basis weight" and "negative pressure". For example, the memory cell combination P1 in the memory cell 49/4 contains the value 0.8 corresponding to, for example, the paper basis weight 80 gr / m2 and in the memory cell 49/5 contains a value correspondingly the negative pressure to be set. However, the stored values do not need to be values representing absolute values, rather it is sufficient to store relative values in relation to a normal setting. In this case, the value 0.8 denotes a relative value of the paper basis weight of 0.8 based on a normal basis weight of 1. The same applies to the stored setting parameter values of the negative pressure.

The memory field 49 is coupled to an arithmetic unit 50, which in this case is designed as a multiplier and which serves to set control setpoints for the control arrangement from the values stored in the memory cells min, low, normal, max, variable or P1 to P3 Calculation of the operating parameters. The values calculated in this way are then stored in working memories 51/1 and 51/2. The working memory 51/1 is assigned to the operating parameter fixing energy and the working memory 51/2 to the operating parameter negative pressure. In the exemplary embodiment shown, the operating parameter "fixing energy" is controlled separately from the operating parameter "negative pressure". In the exemplary embodiment shown, the working memory 51/1 contains three memory cells FIX, VOR, HEIZ for receiving the control setpoints for the fixing energy to be set. The control setpoint assigned to the fixing roller 11 for the fixing roller temperature is stored in the memory cell FIX, the control setpoint assigned to the preheating saddle 21 for the preheating saddle temperature and the control setpoint assigned to the heating saddle 23 for the heating saddle temperature are stored in the memory cell VOR.

The working memory 51/2 contains a memory area for receiving a value corresponding to the negative pressure control setpoint to be set. The memory cells of the working memory 51/1 stand with the one in FIG. 3 Control arrangement shown for controlling the fixing energy in conjunction, the working memory 51/2 for receiving the control setpoints for the vacuum with a vacuum control arrangement regulating the vacuum, which can be designed in accordance with a control arrangement as shown in FIG. 3.

The function of the program-controlled arrangement described is as follows: After the automatic insertion of the paper web into the printing device, the operator is offered menus for entering the paper basis weight (menu G) and menus for selecting the fixing levels (menu F). By automatically or manually entering the paper basis weight, a corresponding call of an assigned memory cell combination P1 to P3 takes place and a corresponding value characterizing the paper basis weight is fed to the computing unit 50, at the same time the working memory 51/1 is assigned the corresponding value for the vacuum control setpoint. The operator then selects the desired fixing level. It normally begins with the fixing level "normal", whereupon the memory content of the memory cell combination "normal" is also applied to the computing unit 50. This calculates the control setpoints for the temperature on the fixing roller, preheating saddle and heating saddle and thus occupies the memory cells of the working memory 51/1. The control arrangement in FIG. 3 now controls the temperature in the fixing station in the manner described. If the operator already knows the recommended fusing level for a certain type of paper, he can choose a fusing level that deviates from normal in advance. However, it is also possible to select the fixing levels empirically depending on the fixing result. If, for example, warping occurs on the paper after it has passed through the fusing station, he selects a different fusing level, for example "low", depending on the type of warping. This corrects the control setpoints Fixing roller, preheating saddle and heating saddle in a corresponding manner.

The program-controlled arrangement now also opens up the possibility of calling program flow menus, e.g. depending on the print jobs to be processed.

In electrographic printing devices that work, for example, with a central processing unit, the called up print jobs are processed as a result of print jobs. Different operating parameters of the fuser can now be assigned to each of these print jobs. For example, the first print job involves printing on thin paper, e.g. Data paper, the following second print job is printing data paper with forms of a predetermined size, the forms being called up electronically, the third printing job is printing data paper in landscape format, etc.

The operator now has the option of compiling or calling up a program sequence menu in which each program step, for example each individual job, is assigned a special menu combination of submenus. In addition to the submenus "paper basis weight" (menu G) and "fuser level selection" (menu F) that have already been written, the menu combination can also contain other submenus (menu X, menu Y). These menus can be called up in the following table, whereby the menus paper basis weight (menu G) and fuser level selection (menu F) can be part of the submenu class "Parameters".

In order to be able to call up or compile this program sequence menu, the arrangement contains, for example assigned to the control unit 43, the arrangement for generating a program sequence menu that is evident from FIG. 7 and is functionally superimposed on the arrangement of FIG. 6.

It contains a menu memory 52 for recording and displaying the callable submenus or for compiling the callable sequence menus, whereby the program sequence menu (menu J) can itself be a callable submenu. A menu combination memory 53 is functionally coupled to the menu memory 52. The menu combination memory 53 is assigned, depending on the program sequence menu called, memory areas in which submenu combinations assigned to the individual program steps are stored. In the case of the program sequence menu "Job" (menu J), the individual memory areas of the menu combination memory 53, job 1 to job 4, are assigned corresponding job-oriented menu combinations. Coupled with the menu combination memory 53 is a menu working memory 54, into which the menu sub-combination is read for processing when a job-oriented menu sub-combination is called up. The submenus located in the menu working memory 54 are then called up and processed one after the other in a manner as has already been described in connection with the menus G and menus F.

For example, if the print job consists of a sequence of four jobs, the operator calls the Job submenu (menu J). As part of the menu J submenu, he is now asked via the control panel to compile the submenu combinations for the individual program steps in this case job 1 to job 4 and to enter the corresponding fixing levels or the paper basis weight for the menus F and G contained therein. After that individual job-oriented submenu combinations are defined, these subcombinations are processed one after the other in print mode after calling up menu J, namely by entering a command via operating unit 43 for processing menu J. Job-oriented, the submenu combinations are retrieved from menu combination memory 53 and read into menu working memory 54 and processed from there.

Claims (11)

1. Electrographic printing or copying machine with a thermofixing station and an arrangement for program-controlled setting of operating parameters of the thermofixing station, the arrangement having:

   - an input arrangement (43) having input means (55, 56, 57) for the input of recording-substrate-specific characteristic data,

   - a fixing stage selection arrangement (52), assigned to the input arrangement (43) and having selection means (menu F), in order to select a fixing stage from fixing stages (MIN, LOW, NORMAL, HIGH, MAX),

   - an evaluation arrangement (42, 48), coupled to the input arrangement, having a memory (49) for the storage of operating parameter settings assigned to the fixing stages (MIN, LOW, NORMAL, HIGH, MAX) and to the characteristic data, of units (11, 15, 16) of the fixing station, and having assignment means (50), in order to allocate control setpoints (TS) to the assigned operating parameter settings as a function of the input characteristic data and the selected fixing stage (MIN, LOW, NORMAL, HIGH, MAX), and

   - a control arrangement (39), coupled to the evaluation arrangement (42, 48) and the units (11, 15, 16) of the fixing station, in order to control the operating parameters of the fixing station (15, 16, 11) as a function of the control setpoints (TS).
2. Electrographic printing or copying machine according to Claim 1, having menu-controlled input and selection means (43, menu F, menu G) in such a way that the input of the characteristic data and the selection of the fixing stages (MIN, LOW, NORMAL, HIGH, MAX) is carried out via input menus (menu F, menu G) which can be called up on an operating panel (43) of the machine.
3. Electrographic printing or copying machine according to Claim 2, having means for generating a program sequence menu (menu J) with a sequence of program steps, each program step being assigned a specific combination of input menus (menu F, G, X, Y), and the selection arrangement (53, 48) allocates control setpoints (TS) to the associated program step as a function of the specific input menu combination.
4. Electrographic printing or copying machine according to one of Claims 1 to 3, having an operating panel keyboard (55) as input means (43).
5. Electrographic printing or copying machine according to one of Claims 1 to 3, having a reading device (56), which scans the characteristic data, as input means.
6. Electrographic printing or copying machine according to one of Claims 1 to 3, having a device for registering the paper grammage (57) as input means.
7. Electrographic printing or copying machine according to one of Claims 1 to 6, having a separate additional input arrangement (45), coupled to the evaluation arrangement (48), for the variable input of operating parameter settings into the evaluation arrangement (48).
8. Electrographic printing or copying machine according to one of Claims 1 to 7, having an evaluation arrangement (48) with memory areas (49/1, 49/2, 49/3) for the storage of control parameters assigned to fixing stages (MIN, LOW, NORMAL, HIGH, MAX), and with memory areas (P1, P2, P3) for the storage of control parameters assigned to characteristic data, desired values being stored as control parameters of the fixing stages (MIN, LOW, HIGH, NORMAL, MAX), and data characterizing the recording substrate grammage being stored as control parameters of the characteristic data, and having a computing arrangement (50) as assignment means which calculates the control setpoints from the desired values and the characterizing data.
9. Electrographic printing or copying machine according to one of Claims 1 to 8, the thermofixing station having:

   - a heatable preheating saddle (15) equipped as a low-temperature saddle,

   - a vacuum brake (16) located upstream of the preheating saddle in the recording substrate running direction and

   - a fixing gap with associated heated fixing roller (11) and at least one nip roller (12).
10. Electrographic printing or copying machine according to Claim 9, with the fixing energy and/or the vacuum as operating parameters.
11. Method for program-controlled setting of the fixing energy of a thermofixing station (11, 21, 23) in an electrographic printing or copying machine, having the following steps:

    - input of recording-substrate-specific characteristic data into an input arrangement (43),

    - selection of a fixing stage (MIN, LOW, NORMAL, HIGH, MAX) from a menu (menu F) of fixing stages via the input arrangement (43), a predetermined setting parameter combination with corresponding setting values from temperature setting parameters, determining the fixing energy, of the fixing station (11, 21, 23) being stored for each fixing stage (MIN, LOW, NORMAL, HIGH, MAX) in a memory (49) which is coupled to the input arrangement (43),

    - calculation of control setpoints (TS) from the setting values and the characteristic data,

    - setting the fixing energy by controlling the temperature setting parameters to the control setpoints (TS) via a control arrangement (42).

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