DE3511386C2 - - Google Patents

Description

The invention relates to a printer in the preamble of Claim 1 described type.

Interchangeable printheads and related components The printing system enables the use of a printer for different printing processes, for example fast Dot-matrix printing, quiet ink-jet printing, thermo printing process or similar

It is already known from DE-OS 31 07 554, which differ to replace those components of a printer, for example wise to be able to print on different types of paper. Here however, when converting the printer are of a paper type on the other always a variety of components, for example as the counter rollers 15'f, additional drive rollers 29 with Counter rollers 30, powder container 26f with brush roller 27, etc. to dismantle or assemble individually, whereby the Workload is very high and there is a risk of error components that do not belong together.

DE-OS 29 31 326 is already an office machine knows where certain parts in the area of type wheel, types wheel feed as well as ribbon feed and correction device are grouped together. A quick and easy Exchange of assemblies or an exchange of the counter pressure camp is not provided at all.

DE-AS 25 44 429 already knows an exchange of the Ge pressure bearing to adapt to different paper pulps A quick exchange of other components of the print systems is not provided.  

Through the IBM Technical Disclosure Bulletin, Vol. 26, No. 10A March 1984, pages 5060, 5061 it is known, the platen by special locking medium to be exchanged quickly. Even in this print However, writing is not a quick exchange of the entire print systems for the purpose of converting the printing process seen.

It is the object of the invention to provide a printer of the generic type appropriate way to create, in which with different Printheads interacting functional elements of the print systems can be replaced with little effort.

According to the invention, this object is characterized by the of the features mentioned solved.

If a certain one, for a desired printing process he required printhead is inserted into the printer, then can use the functional elements corresponding to this printhead te, namely platen and transport and guidance means for the printing medium passing through the printer, as an assembly in functional mutual arrangement and functional arrangement with respect to the printhead are easy to use, the means of transport with the fixedly arranged in the printer housing, not interchangeable Drive means in drive connection or bring are.

In this way, each time a pressure changes head to be exchanged for functional elements. The Summary of the functional elements on a carrier also facilitates the assembly of the printer in production as well as for repairs.  

The components of the printer, all of the printers to be used core system are common, exist only once and z. B. permanently installed in the printer housing. For example the mechanical drives for the feed movement of the Printhead or the print carrier or for the setting the carrier to the printhead can be used for all systems. If the printer is limited to systems where the printed characters from individual drawing elements put together sets, for example needle mosaic, ink mosaic, Thermal mosaic printheads, can also be a fixed one electrical control device for controlling all pressure systems are used.

The invention provides that when inserting the carrier in the transport and guide means automatically get into a functional position in which they drives permanently arranged in the printer housing the.

The invention can be particularly advantageous for printers can be used with multiple printing stations, for example wise for POS printers with a printing station for receipts, Journal and voucher. The printer can do so in its basic equipment are produced in large numbers, whereby the equipment of the various printing stations Customer's request at any time until immediately before delivery can be set individually. In addition, too the user himself single print stations from a print switch procedure to another without completely having to buy a new printer.  

The arrangement according to the invention results above all for printers with multiple printing stations, for example Possibility to use the pressure pressure mainly used with the low-noise thermal printing system, the rarer used printing stations with the cheaper needle printing system, which also includes the production of through beating allowed.

In a practical embodiment of the invention is pre see a printing system with one on one in the printer housing can be placed in the direction of the row movable carrier serial printhead and one on the interchangeable assembly pe trained writing, fixed during operation area is provided as a pressure counter bearing. The interchangeable right assembly also contains other functional elements, namely at least parts of the management and transportation means for the print carrier, as stated above. Instead of the serial printhead can however fiction according to a stationary in the printer housing, as Thermal print bar trained printhead is provided, where then on the replaceable assembly as a pressure counter camp a rotatable platen is provided. The writing roller rotates when transporting the print medium, so that generally does not remove the writing bar from the print medium needs to be lifted.

In a further embodiment of the invention it is provided that the interchangeable assembly between an operating position, where the platen is adjacent to the print head beard standby position and an Ab lifting order, in which the platen from the print head is lifted, is adjustably arranged on the printer housing.  

On the one hand, this will make it easier to thread the print carrier tert, on the other hand access to the printhead, for example for inspection purposes.

Further advantages and features of the invention result from the claims, the drawing and the Drawing description.

Several embodiments of the invention are in this Drawing shown and described below.  It shows

Fig. 1 shows schematically a printer with three writing stations, wherein an interchangeable assembly pe is provided with means for guiding and transporting ribbon-shaped print carriers of two parallel printing stations;

Fig. 2 schematically shows a longitudinal section through a printer according to Figure 1, wherein the upper printing stations are equipped with needle printheads.

FIG. 3 shows a schematic representation according to FIG. 2, the upper printing stations being equipped with a thermal writing strip as a printing head;

Fig. 4 is a perspective partial view of a printing system of Fig. 2;

Fig. 5 is a perspective partial view of a printing system of FIG. 3;

Fig. 6 is a perspective partial illustration of another embodiment of a printing system shown in FIG. 5;

Fig. 7 is a partial perspective view of an embodiment of the printing station shown in Figure 1 below;

FIG. 8 shows a representation according to FIG. 7, this printing station being equipped with a thermal writing strip;

Fig. 9 to 11 schematically illustrate various Betriebsstellun the printing station gen of FIG. 8.

The printer 2 shown in Fig. 1 comprises a printer housing 4 , in which a large part of all of the functional elements of the printer is accommodated, and an attachable to the printer housing 4 attachment 6 , in which further, to an interchangeable assembly summarized functional elements are included , as will be explained in more detail below. The device shown is a POS printer with three printing stations 8, 10 and 12 . In the printing station 8 a receipt is issued, which can be printed on tape-shaped paper and torn off by means of a tear-off device 14 . A continuous journal strip is printed out in the printing station 10 . This is also printed on tape-shaped paper and wound onto a take-up spool 16 . The printing stations 8 and 10 are arranged parallel to one another and are printed by a common print head 18 which can be moved in the direction of the arrow 20 . If the print head 17 is a needle print head or a thermal transfer print head, the printing ink is transferred from an ink ribbon 22 to the print carrier 24 or 26 for receipt or journal. The ink ribbon 22 runs out of an ink ribbon cassette 28 , is guided over the various printing stations and then runs again into the ink ribbon cassette 28 . The printing station 12 is used to print an approximately sheet-shaped printing medium 30 , which serves as a payment receipt. A print head 32 is used for printing on the print carrier 30 , which is also movable in the direction of the arrow 20 and is preferably arranged with the print head 18 on a common carrier. As he lets Fig. 1 know, the ink ribbon 22 is guided so that it can also serve as a carrier for the color printing station 12. Should the upper printing stations or the lower printing station work according to a method in which an ink ribbon is not required, the ink ribbon or the printing head is displaced perpendicular to the line direction in this station so that the printing head lies next to the web of the ink ribbon.

The essay 6 contains guide and transport means for the print carriers 24 and 26 and the print counter, against which the print carriers are present during the printing process. These functional elements are different because depending on whether it is in the printing systems used in stations 8 and 10 z. B. is dot matrix or thermal printing systems, as will be explained in more detail below. The entire essay with the contained therein, summarized into an assembly functional elements is interchangeable, so that the printer 2 can be converted from one printing process to another in a few steps. In addition, on the set 6 is pivotally arranged about the axis 34 , so that the threading of the supply rolls running out in the printer housing 4 th supply rolls 24, 26 it facilitates and access to the in the printer housing 4 of ordered functional elements, in particular the print heads 18, 32 and the ribbon cassette 28 is made possible. In addition, when the attachment 6 is pivoted into the operating position shown, each functional element arranged in this attachment is coupled with functional elements arranged in the pressure housing 4 , as will be explained further below.

The transport rollers 36 and the thrust bearing 38 are arranged on a common frame 40 , which is mounted in the printer housing 4 so as to be adjustable in the direction of the arrow 42 . In the example shown in Fig. 1, the platen 38 is designed as a simple pressure bar with a flat writing surface, such as those used in cooperation with needle printheads, for example. The frame 40 with the transport rollers 36 and the platen 38 are in turn designed as an exchangeable assembly. When changing the printing process of the printing station 12 , the frame 40 and the print head 32 are exchanged.

Fig. 2 shows a very simplified, schematic representation of a section through the printer 2 according to FIG. 1. All printing stations 8, 10 and 12 are designed as needle printing stations. The upper printhead 18 interacts with a platen 44 arranged on the underside of the attachment 6 , which is designed as a flat writing surface. The attachment 6 also contains guide channels 46, 48 (see also FIG. 1) for the print carriers 24, 26 and counter-rollers 50 , which interact with driven transport rollers 52 arranged in the printer housing and further convey the printing paper running off from the supply rollers 54 . As shown in Fig. 2, the attachment 6 can be pivoted into a broken-off te te position, in which the thrust bearing 44 formed on the underside of the attachment 6 from the printhead 18 and the counter rollers 50 are lifted off the trans rollers 52 . This position enables the band-shaped print carriers 24, 26 to be threaded into the guide channels 46 and 48, as well as access to the functional elements arranged in the printer housing.

The lower print head 32 , also designed as a needle print head, for printing on the print carrier 30 interacts with the pressure counter bearing 38 arranged on the frame 40 and designed as a pressure bar. In addition, on the frame 40 driven transport rollers 36 are arranged, which cooperate with counter rollers 56 arranged in the printer housing. The frame 40 is adjustable in the direction of the arrow 42 . In a lower lifting position, the platen 38 from the printhead 32 , the transport rollers 36 are lifted off from the counter rollers 56 , so that the printing medium 30 can be inserted into abutment against the stop 58 . The adjustment speed in the direction of arrow 42 also serves to lift the platen from the printhead 32 for the line transport, as will be described in more detail below.

Fig. 3 shows an arrangement according to FIG. 2, but in which the printing stations 8, 10 are converted to a method for thermal printing. The printing station 12 is still equipped with a dot matrix printing system, so that it does not have to be described again here.

Instead of a wire print head, a thermal print head 60 designed as a thermal writing strip is provided in FIG. 3, which is pivotally mounted in the printer housing about an axis 62 . A compression spring 64 holds the print head 60 in constant contact against the assigned platen.

The essay 66 corresponds in its shape and dimensions essentially to the essay 6 of FIG. 2. It also contains guide channels 68, 69 for the print carrier 24, 26 and in this figure, not shown, counter-rollers, which are arranged in the printer housing with, driven transport rollers work together. This arrangement corresponds to the arrangement shown in FIG. 2 and therefore does not need to be described here again.

A platen roller 70 serves as the pressure counter bearing for the print head 60 and is drive-connected via a drive belt 72 to a pulley 76 arranged on the axis 74 of the counter rollers. In addition, intermeshing gears 80, 82 are arranged on the axis 74 of the counter rollers and on the axis 78 of the transport rollers, which transmit the drive movement of the transport rollers in a suitable ratio to the platen roller 70 . The attachment 66 is in turn arranged as shown in Fig. 2 about the pivot axis 34 pivot bar, so that the gears 80 and 82 come into engagement with each other when pivoting the attachment 66 in the operating position shown.

The thermal print head 60 is constantly against the platen roller 70 or against this print carrier 24, 26 , provided that it is a pure thermal print without using an ink ribbon or the like. The arrangement is such that the thermal print head 60 lies above the ink ribbon 22 , which is still used for the lower printing station 12 .

Fig. 4 again shows a perspective view of details of an arrangement according to FIG. 2. The at the print carrier 24 for the receipt and 26 for the journal each run from assigned supply rolls 54 , are guided over the transport rollers 52 , ge against the counter roles 50 concerns. The print head 18 can move over a line width covering two print carriers 24, 26 in the direction of the arrow 20 who the. On the axis 78 of the transport rollers 52 toothed wheels 82 are arranged, which serve to convert a printing station NEN to drive a rotatable platen, as described with reference to FIG. 3.

Fig. 5 shows a perspective view of a zelheiten an arrangement according to Fig. 3. The print carrier 24, 26 run from the supply rolls 54 between the transport rollers 52 and 50 through to storing the associated counter-rollers to the constructed as a platen roller 70 pressure, and from there through the guide channels of the attachment 66, not shown, to the outside. At the drive of the platen rollers 70 takes place with these ver connected pulleys 71 , drive belts 72 , on the axis 74 of the counter-rollers 50 arranged pulleys 76 as well as the gears 80 arranged on the same axis, each with gears 82 on the axis 78 of the transport rollers 52 are engaged. In the embodiment shown in Figure 5, the axis 74 is formed from two coaxial, interlocking axes, each of which is connected to one of the gears 80 ; one of these axes is used to drive the platen for the receipt, the other to drive the platen for the journal.

The thermal writing strip 60 is likewise divided into two, one part being intended for printing on the print carrier 24 and the other part intended for printing on the print carrier 26 , as can be seen in FIG. 5.

FIG. 6 shows a modification of the arrangement according to FIG. 5. The printing station 84 takes up the entire width of the printer. The pressure carrier 86 consists of two layers 88, 90 . It in turn runs outwards from a supply roll 92 via a transport roll 94 and a platen 96 designed as a platen roller. A ziger, over the entire width of the print carrier 86 rich, designed as a thermal writing head print head 98 describes, for example, directly the layer 88 made of active paper and indirectly in a thermal transfer process by means of dyes arranged on the back of the layer 88 , the layer 90 , wherein layer 88 serves as a tear-off receipt, layer 90 serves as a continuously wound journal. The drive of the platen roller 96 he in turn follows via a belt drive 100 and a gear connection 102 from the driven transport roller 94 , as need not be described.

Fig. 7 shows a perspective view of a printing station 12 according to FIGS . 1 to 3. Corresponding components le are provided with corresponding reference numerals. The platen 38 and the transport rollers 36 are arranged on a common frame 40 which is arranged in Rich direction of the arrows 42 in the printer housing. The frame 40 can take two or three different positions depending on the type of printing system used. In a needle printing system of Fig. 2 or 3 as well as in an ink mosaic printing system there are two positions.

In an inoperative position, both the thrust bearing 38 from the printhead 32 and the transport rollers 36 are lifted off the counter rollers 56 , so that a print carrier can be inserted up to the stops 58 . In an operating position of the framework mens 40, the transport rollers 36 bear against the counter-roll 56 or the interposed pressure support, while the platen 38 by the print head 32 nen ei for the line conveying the pressure wearer suffi sponding gap has, in which the printing carrier be printed are can. The print head 32 can be a dot-matrix print head, in which case an ink ribbon must then be arranged between this print head 32 and the print carrier, as shown in FIGS. 1 to 3. The printhead can also be designed as an ink mosaic printhead, an ink ribbon being omitted.

If the printing station 12 is to be converted to a thermal printing process, the frame 40 with all the functional elements arranged thereon and combined into an exchangeable assembly is exchanged for a frame 104 which has the functional elements required for the thermal printing process, as shown in FIG. 8 shows. The platen 106 is designed as a rotatable platen roller, the gear via a gear 108 is coupled to the axis of the transport rollers 110 ge. In turn, a thermal writing strip serves as the print head 112 , against which the platen 106 can be placed from below. In this case, the frame 104 can take three positions, namely an inoperative position, a transport position and an operating position.

FIGS. 9 to 11 schematically show the possible positions of the frame 104. In Fig. 9, this frame 104 is in its lower inoperative position, in which the transport rollers 110 from the counter rollers 56 , the platen 106 are lifted from the writing bar 112 . In Fig. 11, the frame 104 is moved upwards so far that the transport rollers 110 bear against the counter rollers 56 , so that a transport of a pressure medium located between these two Rollensy is possible. As can be seen in FIG. 11, the platen roller 106 does not yet bear against the platen 112 in this position. To 104 in Fig. 10 is the frame in its upper operating position, in which the platen roller abuts 106 against the print bar 112, so that a printing medium located between them can be printed. As is apparent from Fig. 10, the Ge gene rollers 56 are resiliently mounted in the feed direction of the frame 104 so that they can participate in the movement of the transport rollers 110 from the position shown in Fig. 11 in the position shown in Fig. 10. In contrast, there is also the possibility of rotating the frame 104 from the position it holds in FIG. 11 about the axis 114 of the transport rollers 110 in a clockwise direction until the platen roller 106 bears against the platen 112 . The possibility of lifting the platen from the platen during the port of the print carrier is especially necessary when using a thermal transfer method in which a sensitive color pigment carrier is arranged between the platen 106 and the print carrier.

Claims (12)

1. Printer with at least one printing system in which the print characters are composed of individual elements and which has an exchangeable print head, an exchangeable platen and replaceable, in a functional position in the printer by means of drives arranged in the printer housing, drives and transport means for a the printing system continuous printing medium, characterized in that the platen ( 38, 44, 70, 96, 106 ) and the trans port and guide means ( 36, 46, 48, 50, 68, 69, 80, 110 ) in functional mutual assignment a Trä ger ( 6; 40, 66, 104 ) are arranged, which can be used as a separate assembly in the printer housing ( 4 ), where the thrust bearing ( 38, 44, 70, 96, 106 ) and the trans port and guide means ( 36, 46, 48, 50, 68, 69, 80, 110 ) come into a functional position in which the trans port and guide means ( 36, 46, 48, 50, 68, 69, 80, 110 ) with the in Printer case ( 4 ) arranged drives (z. B. 82 ) are coupled or can be coupled. 2. Printer according to claim 1, characterized in that the interchangeable assembly between a first functional position in which the platen ( 38, 44, 70, 106 ) in the ready position Druckbe to the respective print head ( 18, 32, 60, 98, 112 ) lies, and a second functional position, in which the platen ( 38, 44, 70, 106 ) from the respective pressure head ( 18, 32, 60, 98, 112 ) is lifted, is arranged adjustably on the printer housing ( 4 ). 3. Printer according to one of claims 1 and 2, characterized in that the print head ( 18, 60, 98 ) in the upper region of the printer housing ( 4 ) is arranged with upwardly pointing writing elements and that the interchangeable assembly as se on the printer housing ( 4 ) attachable attachment ( 6, 66 ) with guiding and transport devices ( 46, 48, 50, 68, 69, ), which are formed essentially on the underside and cooperate with drive elements ( 82, 102 ) arranged on the upper side of the printer housing ( 4 ) . 80 ) and a pressure counter bearing ( 44, 70, 96 ) for the print carrier is formed. 4. Printer according to claim 3, characterized in that the attachment ( 6, 66 ) about a parallel axis in the line direction ( 34 ) pivot bar on the printer housing ( 4 ) and that when pivoting the attachment ( 6, 66 ) in the the Druckerge housing ( 4 ) lying on the first functional position of this on ordered counter-rollers ( 50 ) with in the printer housing ( 4 ) on orderly transport rollers ( 52, 94 ) to the system. 5. Printer according to claim 4, characterized in that the platen ( 70 ) is designed as a rotatable with the transport rollers ( 52 ), rotatable platen, wherein in the first functional position of the attachment ( 66 ) with the Transportrol len ( 52 ) rotatably connected drive elements ( 82 ) with on top ( 66 ) arranged drive elements ( 80 ) reach in rotary grip, which in turn are coupled via further drive gear means ( 72, 71 ) to the platen. 6. Printer according to claim 1 and 2, characterized in that the print head ( 32, 112 ) in the lower region of the printer housing ( 4 ) is arranged with downward-pointing writing elements and that the replaceable assembly is a head below the print ( 32, 112 ) in the printer housing ( 4 ) includes vertically adjustably mounted frame ( 40, 104 ), which on the one hand cooperates with counter-rollers ( 56 ) arranged in the printer housing ( 4 ) and has transport rollers ( 36, 110 ) driven by the drive, and on the other hand the counter-pressure bearing ( 38, 106 ). 7. Printer according to claim 6, characterized in that the frame ( 40 ) between a first functional position in which the trans port rollers ( 36 ) or the platen ( 38 ) from the counter rollers ( 56 ) and the print head ( 32 ) are lifted , in a second functional position, in which the transport rollers ( 36 ) are in contact with the counter rollers ( 56 ) and the platen ( 38 ) has a certain writing distance from the printhead ( 32 ). 8. Printer according to claim 6, characterized in that the frame ( 104 ) between a first functional position, in which the transport rollers ( 110 ) or the platen ( 106 ) from the counter-rollers ( 56 ) or the print head ( 112 ) ben are, via a second functional position, in which the platen ( 106 ) is lifted, the transport rollers ( 110 ) are in contact with the counter-rollers ( 56 ), in a third functional position, in which the platen ( 106 ) rests on the print head ( 112 ) and the transport rollers ( 110 ) bear against the counter rollers ( 56 ). 9. Printer according to claim 8, characterized in that the frame ( 104 ) is linearly shifted from the first functional position into the second functional position and that it is pivoted to achieve the third functional position about the axis ( 114 ) of the trans port rollers ( 110 ) . 10. Printer according to claim 8, characterized in that the counter rollers ( 56 ) are resiliently mounted in the pressing direction. 11. Printer according to one of claims 6 and 8 to 10, characterized in that the pressure counter bearing ( 106 ) as a with the transport rollers ( 110 ) coupled, rotatable platen and the print head ( 112 ) is designed as a thermal head lying on the print carrier. 12. Printer according to one of claims 6 and 7, characterized in that the pressure counter bearing ( 38 ) as in the frame ( 40 ) fixedly arranged writing bar and the print head ( 32 ) as a non-on the print carrier lying needle or ink mosaic print head is trained.