EP1328849B1 - Electrophotographic printing device of modular construction - Google Patents

Abstract

The device has a bearer (15) with a transport device (16) for a substrate and one or more electrophotographic units (12a) between a starting and target position with a developer unit, a photoconductor and an illumination unit associated with the photoconductor. The bearer has two or more holding positions in series with standard mechanical interfaces, whereby the electrophotographic units have fixing parts matching the interfaces. Independent claims are also included for the following: a use of the printer for printing onto flat, flexurally stiff substrates.

Description

The invention relates to a modular electrophotographic printing device with a support device, which has a transport device on which a substrate to be printed between a start and end position is transportable, wherein between the start and end position on the support device a plurality of electrophotographic units are attached.

A printing device of this kind is from the EP 0932851 B1 known. In this known printing device, the units required for the printing operation are arranged one behind the other from the start to the target position in a specific sequence. The units are designed for a specific printing program with certain individual operations such as charging, drawing generation, development, exposure, transhipment and the like, and in the target position, the transfer of the printed image in the form of a toner image on a moving print carrier, which may also be a substrate is moved on another transport device. The transport device with the electrophotographic units is used only for receiving the toner image and transporting it into the transfer zone.

It can be clearly seen that the known printing device requires a considerable amount of transport devices. In addition, the printing device can not be switched to different printing processes and easily provided with other units in a different order between start and end position.

There are other printing devices are known that are designed for specific printing processes or in which the electrophotographic units themselves can be interconnected, such as US A5,208,612 shows. The structure of the printing device can also be done without connection to the transport device with juxtaposed units, such as US-A-4,569,582 and the PATENT ABSTRACTS OF JAPAN VOL.2000, no 06,22.September 2000 (2000-09-22 ) - & JP 2000 081 827 A (CANON INC) 21.March 2000 (2000-03-21) can be seen. A flexible and universal adaptation of the printing device to various printing processes is not possible.

It is an object of the invention to provide a modular electrophotographic printing device that is easily adaptable to different printing processes.

This is achieved according to the printing device according to claim 1, characterized in that the support device in the transport direction of the transport device lying behind several receiving positions with uniform mechanical and electrical interfaces for attaching electrophotographic units, said units having fastening parts which are formed adapted to the interfaces.

The electrophotographic units form independently functional assemblies that can be positioned on the support frame according to the user's choice. Depending on the print job to be done, one or more electrophotographic units may be used. As a result, it is then possible successively different toner with different technical properties or different color for the decoration and / or modification of aberfiächeneigenschaf printing of plate-shaped materials. Since the supporting device forms uniform interfaces, the electrophotographic units can be easily mounted and assigned.

According to a possible variant of the invention, provision may be made for the carrying device to be composed of at least two sub-frames placed one behind the other, and for the sub-frames to be identical and each to have at least one receiving position for an electrophotographic unit. In this way, the support device can be constructed in the desired manner, adapted to the individual requirements. In this case, primarily the number of electrophotographic unit to be used will determine the number of subframes.

In addition, it can then also be provided that the transport device is guided over the subframes as a unitary assembly or that each subframe has its own sub-transport device, and that the individual sub-transport devices to form a unitary transport device together mechanically and / or via an electrical Drive control are coupled. The connection of the sub-transport devices ensures a synchronous feed, so that the substrate can be transported at a constant speed.

In order to ensure an ordered supply of the substrates, it can be provided that in the region of the start position a centering module is attached to the carrier device. The centering module thus again represents a unitary assembly, which can be attached to the printing device like a kit.

It may also be provided that the pre-centering module is assigned to the centering module upstream in the transport direction, and that the pre-centering module is mounted on the support device or on the centering module. In conjunction with the centering module, the pre-centering module ensures precise alignment of the substrates and their orderly feeding.

According to a preferred embodiment of the invention, it is provided that a fixing module is arranged on the support device or on the electrophotographic unit, which serves for prefixing or for fixing the toner applied to the substrate. After the toner has been applied through the one or more electrophotographic units, the toner can be connected to the surface of the substrate via the fixing module by means of a suitable introduction of energy. The pre-fixing of the toner after the toner application has proven to be particularly useful when, for example, ceramic colors are printed. These ceramic colors are usually applied to substrates on glass or glass ceramic. After leaving the printing device, the substrate with the prefixed toner for final fixation of a unit is supplied, in which the toner is fixed at high temperature, in particular fired at ceramic toners or cured in thermosetting toners.

The fixing module may have fastening parts by means of which it can be coupled to the interfaces of the support device. The interfaces thus do not serve solely for the attachment and exact alignment of the electrophotographic units, but also the one or more fixing modules.

As already mentioned above, a single fixing module can be provided for a printing device. This would then usually in the transport direction be arranged according to the individual electro-photographic units. However, it is also conceivable that each electrophotographic unit is associated with a fixing module, with which intermediate fixations are possible. This may be particularly important, for example, when toner to be printed one above the other.

In the region of the target position of the printing device, an outlet module can be provided. By means of this, an orderly discharge of the printed substrates can be achieved. The outlet module can be, for example, a stacking device that is attached to the carrying device.

So that in particular flat substrates with large wall thickness, for example glass plates, glass ceramic plates, wooden plates or plastic plates can be reliably printed, provides a conceivable embodiment of the invention that each electrophotographic unit has a transfer system for transferring the toner to the substrate, and that upstream of the transfer system in the transport direction Primary charging means and in the transport direction downstream of a secondary charging means is assigned. By means of the primary and the secondary charging means, the surface of the substrate can be electrostatically charged. Conceivable charging means are charging brushes, charging rollers or charging corones, which preferably act on the surface of the substrate to be printed. When passing through the electrophotographic unit, the substrate is first charged with the primary charging means. Subsequently, the substrate enters the area of the transfer system, where a toner transfer takes place.

The substrate is then advanced to the secondary loading means where it is reloaded. Depending on the size of the substrate or of its Positioning on the transport device, the substrate is now connected either to both the primary charging means and the secondary charging means or alone to the secondary charging means. It should be ensured that the substrate is always connected to and charged by at least one charging means during the coating process.

To form a full-color printing system, for example, four electrophotographic units can be mounted on the support device, wherein colored toner, namely cyan, magenta, yellow or black colored toner, is stored in the individual electrophotographic units. The individual colors can be printed on top of each other, if necessary with intermediate fixation or side-by-side printing and thus mixed with each other. This can be produced in a known color more colors.

Fig. 1

in schematischer Darstellung eine Druckvorrichtung mit einer elektrofotografischen Einheit und

Fig. 2

in schematischer Darstellung ein Vollfarb-Drucksystem.

The invention will be explained in more detail below with reference to exemplary embodiments illustrated in the drawings. Show it:

Fig. 1

a schematic representation of a printing device with an electrophotographic unit and

Fig. 2

a schematic representation of a full-color printing system.

In the Fig. 1 is a printing device for printing plate-shaped materials shown. With this printing device, a single-color printing can be done.

The Druckvorrrichtung has a support device 15, which is associated with a transport system 16. Along the transport system various components are arranged. By means of the transport system, a substrate can be transported between a start and a destination position. The substrate may be, for example, a glass ceramic plate, a glass plate, a ceramic plate or a plastic plate. Further provided is the printing of flexible substrates, such as plastic films, leather, fabrics, etc., which are then fixed during the printing process on a rigid base, which is located on the transport device or part thereof. In the area of the start position, a pre-centering module 10 is arranged. By means of this, the substrate is roughly positioned. Subsequently, the substrate is fed by means of the transport device 16 to a centering module 11, in which it is aligned exactly. After the positional alignment of the substrate, this is supplied to an electrophotographic unit 12a.

The electrophotographic unit 12a has a developer, a photoconductor and a transfer system 12.2. Furthermore, the electrophotographic unit 12a has an exposure arrangement, by means of which a latent charge image can be generated in a known manner on the photoconductor. Due to this charge image, a toner material stored in a separate toner cartridge of the developer is transferred to the photoconductor by the developer. The photoconductor then transfers the toner onto the substrate directly or with the aid of the transfer system 12.2. In order to ensure toner transfer to the substrate with good quality, the transfer system 12.2 is preceded by a primary charging means 12.1 and a secondary charging means 12.3 connected downstream. The primary and secondary charging means introduce a charge into the surface of the substrate to be printed. This is through the Andordnung maintained from the primary charging means and secondary charging means during the entire coating process.

After the toner has been applied to the substrate, it passes through a fixing module 13. In the fixing module 13, the toner is bonded to the substrate under the action of temperature. Subsequently, the substrate enters an outlet module 14, in which it is removed from the printing device, runs into a stacking device, for example into a buffer, or passes through a corresponding chaining to further processing manufacturing stations.

The support device 15 is designed to have uniform mechanical interfaces for both the electrophotographic unit 12 a and the fixing module 13. Electro-photographic unit 12a and the fixing module 13 accordingly have fastening parts which are adapted to the mechanical and electrical interfaces of the support device. For a quick and easy assignment of these units to the support device 15 is possible.

In the Fig. 2 is a full-color printing system shown. Similar to the embodiment according to the Fig. 1 a carrying device 15 with a transport system 16 is used. The support device 15 has, lying one behind the other, five mechanical interfaces to which an electrophotographic unit 12a, 12b, 12c, 12d or a fixing module 13 can be fastened. Since the mechanical and electrical interfaces are uniform, the electrophotographic units 12a to 12d can be arranged in any order. In each of the electrophotographic units 12a to 12d, a toner is stored.

However, the toners are differently colored, for example, in the first electrophotographic unit 1 2a, a magenta-colored, in the electrophotographic unit 12b a yellow, in the electrophotographic unit 12c a cyan and in the electrophotographic unit 12d a black toner be stored.

As the Fig. 2 can be seen on the support device 15 are similar to the Fig. 1 again a pre-centering module 10, a centering module 11, a fixing module 13 and a discharge module 14 are mounted. Furthermore, a transport system 16 is used, which links together the individual units of the printing device.

Claims (13)

1. Modularly constructed electrophotographic printing device having a support device (15), which has a transport device (16) on which a substrate to be printed can be transported between a start position and a target position, a plurality of electrophotographic units (12a to 12d), which have a photoconductor, a developer unit and an exposure unit assigned to the photoconductor, being attached to the support device (15) between the start and target positions characterized in that the support device (15) has, one after another in the transport direction of the transport device (16), a plurality of holding positions having standardized mechanical and electrical interfaces for the attachment of electrophotographic units (12a to 12d), these units (12a to 12d) having fixing parts which are designed to match the interfaces.
2. Printing device according to Claim 1, characterized in that the support device (15) is assembled from at least two part frames placed one after another, and in that the part frames are structurally identical and in each case have at least one holding position for an electrophotographic unit.
3. Printing device according to Claim 2, characterized in that the transport device (16) is guided over the part frames (15) as a standardized subassembly or in that each part frame has a separate part transport device, and in that the individual part transport devices are coupled to one another mechanically and/or via an electric drive control means in order to form a standardized transport device (16).
4. Printing device according to one of Claims 1 to 3, characterized in that, in the region of the start position, a centring module (11) is fitted to the support device (15).
5. Printing device according to Claim 4, characterized in that the centring module (11) is assigned a pre-centring module (10), connected upstream in the transport direction (16), and in that the pre-centring module (10) is fitted to the support device (15) or to the centring module (11).
6. Printing device according to one of Claims 1 to 5, characterized in that a fixer module (13) is arranged on the support device (15) or on the electrophotographic unit (12a - 12d) and is used for the pre-fixing or for the final fixing, for example baking or curing, of the toner applied to the substrate.
7. Printing device according to Claim 6, characterized in that the fixer module (13) has fixing parts by means of which it can be fitted to the interfaces of the support device (15).
8. Printing device according to either of Claims 4 and 5, characterized in that a fixer module (13) is arranged after each electrophotographic unit (12a - 12d).
9. Printing device according to one of Claims 1 to 8, characterized in that, in the region of the target position, an output module (14), for example a stacking device, is fitted to the support device (15).
10. Printing device according to one of Claims 1 to 9, characterized in that, in the region of the target position, there is arranged an output module (14) for linking to further-processing finishing devices.
11. Printing device according to one of Claims 1 to 10, characterized in that each electrophotographic unit has a transfer system (12.2) for transferring the toner to the substrate, and in that the transfer system is assigned a primary charging means (12.1), connected upstream in the transport direction, and a secondary charging means (12.3), connected downstream in the transport direction.
12. Printing device according to one of Claims 1 to 11, characterized in that, in order to form a full-colour printing system, four electrophotographic units (12a - 12d) are fitted to the support device (15), coloured toner, specifically cyan, magenta, yellow and black toner, being stored in the individual electrophotographic units.
13. Use of the printing device according to one of Claims 1 to 11 for printing flat, rigid substrates.

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