GB2387142A

GB2387142A - Register control for printing onto a ribbon

Info

Publication number: GB2387142A
Application number: GB0207984A
Authority: GB
Inventors: Nicholas David Michaelson
Original assignee: Silver Fox Ltd
Current assignee: Silver Fox Ltd
Priority date: 2002-04-06
Filing date: 2002-04-06
Publication date: 2003-10-08
Anticipated expiration: 2022-04-06
Also published as: WO2003086772A1; GB2387142B; GB0207984D0; AU2003217052A1

Abstract

An assembly for printing (10), comprising at least one supply (26, 28) of printable medium (11) and a supply (30) of control medium (24) arranged on a common support such that both media may be passed together, in use, along adjacent paths at the same speed through printing apparatus, the supply of control medium having register control marks (41 Fig 4) along its length, the register control marks being detectable by the printing apparatus for controlling the register of printing operations on the said supply or supplies of printable medium performed by the printing apparatus as the printable and control media are passed through the printing apparatus.

Description

2387 1 42

Register Control for Printina onto a Ribbon The present invention relates to an assembly for printing onto printable media, to printing apparatus for printing, and to a method of printing. It is 5 particularly applicable, but by no means limited, to printing heat-shrinkable plastics to serve as labels.

Heat shrinkable plastics tubing is used for labelling electric cables and the like, with each separately labelled section of tubing being cut or perforated to 10 allow subsequent tearing, and then threaded over the corresponding cable before being heat shrunk to secure it in place on the cable. Because of the difficulty of printing direct onto the flattened plastics tubing, labels are generally mounted independently onto a carrier which is then fed through a printer. This of course is costly, involving many separate operations including pre-cutting the 15 plastics tubing into lengths and fixing them to a roll of carrier material, and is difficult to automate. Alternatively pre-marking of the printable media is necessary. The purpose of the present invention is to enable flattened plastic tubing to be printed direct with a sequence of labels along its length.

; .. 20 Accordingly, the invention provides an assembly for printing, cor'np,rising at least one supply of printable medium and a supply of control medium- arranged on a common support such that both media may be passed together, ins use, along adjacent paths at the same speed through printing apparatus, the' supply of control medium having register control marks along its length, the register control 25 marks being detectable by the printing apparatus for controlling the register of printing operations on the said supply or supplies of printable medium performed by the printing apparatus as the printable and control media are passed through the printing apparatus. The term 'printable medium' should be interpreted broadly, to include conventional paper as well as heat shrinkable plastics tubing 30 and other labelling media. Different sizes of printable media may be accommodated by this assembly.

The invention allows conventional printing apparatus, for example thermal printers, to be used with minimal modification for printing direct onto a printable 35 ribbon with satisfactory register control for the printing. Thus printing apparatus according to the invention comprises printing apparatus comprising means for

feeding at least one printable medium over a printer head, a detector responsive to register control marks to control the sequence of printing operations on the medium, and a register control medium arranged to be fed by the same feeding means in parallel with the printable medium at the same speed past the detector, 5 the register control medium having longitudinally spaced register control marks.

The invention also provides a method of printing on a printable medium, comprising feeding the printable medium over a printer head and simultaneously 10 feeding a register control medium over a detector responsive to register control marks on the register control medium, to control the sequence of printing operations on the printable medium.

In order that the invention may be better understood, a preferred 15 embodiment will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a schematic top view of a thermal printer embodying the invention; Figure 2 is an axial section through an assembly embodying the invention; Figure 3 is a side view of a guide comb for use in the printing apparatus 25 of Figure 1; Figure 4 illustrates part of a print register control ribbon; Figure 5 illustrates part of a printable heat-shrinkable ribbon printed with 30 labels under the register control of the corresponding portion of print register control ribbon shown in Figure 4; and Figure 6 is a side view of a spooled heat-shrinkable printable ribbon capable of use with the invention.

Printing apparatus, in the form of a modified conventional thermal printer 10, is shown in Figure 1. The printer may have a foot print of approximately 30cm x 20cm and be approximately 15cm high, although it could measure any size. The top view of Figure 1 is very schematic and is visible once a lid (not 5 shown) is hinged open. One compartment 14 is intended to accommodate a sacrificial printing component such as a drum of waxed paper for thermal printing, and a take-up drum 102 and in this example a supply drum and a take up drum are journalled on axes 12 and 13, with the thermal ribbon 11 being guided past a print head beneath the thermal ribbon and between the drums.

At the other end of the printer, a compartment 15 is arranged to accommodate an assembly for the printable medium, which in this example is an assembly of heat-shrinkable printable plastics tubing on spools, the assembly being shown in Figure 2. The assembly is mounted on an axis 16 common to all 15 the spools containing the ribbon (although this need not be the case), and is journalled at 17 and 18 for rotation on the axis 16.

An optical detector 20 or reflector is arranged in the printer to detect print register control marks on a print register control ribbon 24 as it passes beneath 20 the detector, and the printer has a control system (not shown) responsive to signals from the detector 20 to control the sequence of printing operations carried out by the print head 10 on the adjacent printable ribbons 22, 23 which are printed in parallel.

25 As shown in greater detail as an end view in Figure 3, the printer has a guide comb 21 for guiding the three respective ribbons 22, 23 and 24 transversely as they move from the print head through the printer and out of the printer through a slot 19 at the end of the printer. Alternatively, there are replaceable combs of different shapes to accommodate respective printable 30 media. The ends of the slot can be adjustable (not shown) to accommodate printable media of different widths. The end or ends may be defined by a movable end stop, or by a pin placed through a hole in the guide.

There may be a guide comb close to the place that the medium exits the 35 printer, or somewhere along the path of the medium within the printer, or both.

In this example, a metal cylindrical spindle 31 is mounted on the axis 16 in the journals 17, 18, and the replaceable ribbon assembly is slid over the spindle 31. The ribbon assembly has a cylindrical cardboard tube 25 on which are mounted two spools 26, 28 of printable heat-shrink plastic flattened tubing 5 22, 23, of which a side view is shown in Figure 6. In this example, the ribbons 22, 23 have different widths. For the sake of consistent alignment of printing operations in the print head 10, however, the left hand edge of each ribbon 22, 23 is arranged to lie at the same transverse position in the printer, regardless of the width of ribbon, and this is achieved by using hollow cylindrical spacers 27, 10 29 of equal length along the axis 16, to form the spools. Instead of hollow, coaxial spacers, there may be some form of alternative spacer such as a bar, or transverse projection from the spools or spindle. The ribbons may be wound directly on these spacers, abutting the inner surfaces of cardboard discs 26, 28, or alternatively they may be wound on cardboard cylinders which themselves are 15 mounted over the spacers 27, 29. It will be appreciated that many possible variations of the example given in Figure 2 are possible.

A paper or plastics ribbon 24 intended for print register control is wound on a similar spool 30, although in this example no spacer is required. The spools 20 26, 28 and 30 are all mounted coaxially and the ribbons are all wound in the same rotational sense. The print register control ribbon 24 is pre-printed with register control marks as for example the marks 41 shown on a section of the ribbon 24 in Figure 4. These marks are intended to signal the beginning or end - of each separate page of labels or label 39 which is to be printed on the ribbon 25 22 or 23, as shown in Figure 5, each separate label 40 being, in this example, of the same longitudinal length. It will be appreciated, however, that any type of printing along the length of the ribbon is possible under any register control scheme. The marks 41 could be of any type, and could be apertures or magnetic marks or the like, provided they may be detected by the printer. The 30 print register control ribbon 24 is intended to pass always across the same part of the printer, so that the detector 20 reliably detects the register marks.

It may be required to print between labels. There may therefore be operating processing means to subdivide the regions between the register 35 control marks and thereby effect printing on printable regions on the printable

medium in positions between the corresponding register control marks. A line may be printed at a position corresponding to each of these subdivisions.

The transverse alignment of the ribbons 22 to 24 is controlled by one or 5 several guides, which in this example are in the form of metal or plastics combs 21 shown in Figure 3. The combs are arranged to accommodate a variety of different widths of ribbon 22, 23: the left most ribbon in Figures 2 and 3 would rest on shoulders 32 if it were the widest ribbon; or on shoulders 33 if it were less wide; and the ribbon 22 shown, being the narrowest, would fit into the recess 34.

10 Correspondingly for ribbon 23, there are pairs of shoulders 35 and 36 for relatively wide ribbons, and a recess 37 for the narrowest. The shapes and configurations of these guides may be varied to suit different types of printing operation and different materials of ribbon. In this example, just one guides recess 38 is shown for the register control ribbon 24.

An arrangement may be provided for locating each ribbon 22 to 24 vertically within the guides in the comb 21 to ensure that the ribbons remain in their correct paths of travel during printing operations, when the lid of the printer is closed. For example, leaf springs may be provided over the comb 21, biasing 20 the ribbons downwardly.

The spools of Figure 2 may each have two discs such as disc 26 for retaining the ribbon, and adjacent spools may be adhered to each other for example with the use of double sided adhesive tape. Thus the spools may be in 25 the form of bobbins or reels.

In this example, the ribbons are driven by rotation of the spindle 31 and advanced under the control of the printer which responds to the register marks.

Alternative drive arrangements would be possible.

In use, an assembly as shown in Figure 2 is mounted over the spindle 31 and inserted into the compartment 15, threading each ribbon over the guides 21 and through the slot 19 as shown in Figure 1. The printer is operated in a conventional fashion to print a sequence of labels or other printed matter onto 35 each printable ribbon, under the control of signals derived from the register control marks 41 on the register control ribbon which passes at the same speed

as the printable ribbons through the printer. In this example, the register control ribbon is sacrificed once the printable ribbon has been used up, and the entire assembly of Figure 2 is replaced for the next sequence of printing.

5 In some alternative embodiments of the invention, the spooled register control ribbon could be replaced with a reusable loop of marked ribbon. This could be removable from the assembly containing the printable ribbon, but in use it would be driven together with the printable ribbon and at the same longitudinal speed through the printer.

The printable medium is preferably in the form of ribbon, i.e. elongate, flat and of uniform thinness, but this is not essential. The printable medium and/or the register control medium are conveniently stored by winding them around spools, such as bobbins or reels, but other carriers such as cartridges are 15 possible, and the media could be fan-folded for fan-feeding. The common support is shown in the example as a cylindrical support mountable over a spindle, but other supports, rotary or otherwise, are possible, and indeed the supplies of the media need not be coaxial.

Claims

1. An assembly for printing, comprising at least one supply of printable medium and a supply of control medium arranged on a common support such 5 that both media may be passed together, in use, along adjacent paths at the same speed through printing apparatus, the supply of control medium having register control marks along its length, the register control marks being detectable by the printing apparatus for controlling the register of printing operations on the said supply or supplies of printable medium performed by the 10 printing apparatus as the printable and control media are passed through the printing apparatus.

2. An assembly according to Claim 1, in which at least one of the printable

media comprises a ribbon.

3. An assembly according to Claim 2, in which the or each printable ribbon is wound on a corresponding spool.

4. An assembly according to Claim 1, in which at least one of the printable 20 medium supplies comprises the medium folded and arranged to be fan-fed.

5. An assembly according to Claims 1, 2, 3 or 4, in which at least one of the printable medium supplies comprises a cartridge.

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6. An assembly according to any preceding claim, in which the control medium comprises a ribbon.

7. An assembly according to Claim 6, in which the control ribbon is wound on a spool.

8. An assembly according to any preceding claim, in which the control medium is arranged to be fan-fed.

9. An assembly according to any of Claims 1 to 7, in which the control 35 medium is in the form of a continuous loop.

10. An assembly according to Claim 3 or Claim 9, wherein the spool is in the form of a bobbin or reel.

11. An assembly according to any preceding claim, wherein the supply of 5 control medium is fan-fed.

12. An assembly according to any of Claims 1 to 10, wherein the supply of control medium is in the form of a continuous loop.

10

13. An assembly according to any of Claims 1 to 10, wherein the supply of control medium is in the form of a spool or cartridge.

14. An assembly according to Claim 13, wherein the spool is in the form of a bobbin or reel.

15. An assembly according to any preceding claim, wherein the supplies of printable medium are adjacent and mutually abutting on the common support.

16. An assembly according to any of Claims 1 to 14, further comprising a 20 hollow spacer or separator mounted coaxially between two adjacent supplies of printable medium, and means for ensuring the mutual abutment of the medium supplies and the spacer along the common axis of the supplies.

17. An assembly as claimed in Claim 16, wherein the spacers or separators 25 are of a predetermined unique length.

18. An assembly as claimed in Claim 16, wherein the spacers or separators are of a variety of lengths such that, in use, a length of spacer can be selected to compensate for the width of the printable medium so as to ensure that the 30 printable media are spaced at predetermined positions along the common support.

19. An assembly according to Claim 3, wherein the or each spool has a disc normal to the common axis of the spools, against which disc lies the ribbon's 35 edge.

20. An assemblyaccording to Claim 19, further comprising a spacer mounted between two adjacent spools and abutting the discs of the two adjacent spools.

21. Printing apparatus comprising means for feeding at least one printable 5 medium over a printer head, a detector responsive to register control marks to control the sequence of printing operations on the medium, and a register control medium arranged to be fed by the same feeding means in parallel with the printable medium at the same speed past the detector, the register control medium having longitudinally spaced register control marks.

22. Printing apparatus according to Claim 21, arranged to accommodate an assembly according to any of Claims 1 to 20 such that the feeding means feeds, in use, the printable medium to the printer head as it feeds the register control medium past the detector.

23. Printing apparatus according to Claim 22, comprising an assembly according to any of Claims 1 to 20 arranged to print onto the printable medium under the register control of the register control medium.

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24. A method of printing on a printable medium, comprising feeding the printable medium over a printer head and simultaneously feeding a register control medium over a detector responsive to register control marks on the register control medium, to control the sequence of printing operations on the printable medium.

25. A method as claimed in Claim 24, wherein the printable medium comprises a sequence of printable regions, and wherein the register control marks on the register control medium are positioned so as to cause the printer head to print on the said printable regions.

26. A method as claimed in Claim 25 wherein the printable regions are labels.

27. A method as claimed in Claim 25 or Claim 26 further comprising operating processing means to subdivide the regions between the register control marks 35 and thereby effect printing on printable regions located on the printable medium in positions between the corresponding register control marks.

28. A method as claimed in Claim 27, further comprising printing a line on the printable medium at a position corresponding to each of the said subdivisions.

5

29. Printing apparatus according to any of Claims 21, 22 and 23, further comprising a guide for guiding the printable medium to the printer head.

30. Printing apparatus as claimed in Claim 29, wherein the guide comprises an elongate slot through which printable medium may be fed.

31. Printing apparatus as claimed in Claim 30, wherein the ends of the elongate slot are adjustable to accommodate printable media of various widths.

32. Printing apparatus as claimed in Claim 31, wherein an end of the elongate 15 slot is defined by a moveable end-stop.

33. Printing apparatus as claimed in Claim 31, wherein an end of the elongate slot is defined by a pin placed through a hole in the guide.

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34. Printing apparatus as claimed in Claim 29, wherein the guide comprises a recess, the depth of the said recess varying across its width, and the varying depth of the recess being arranged so as to enable different widths of printable media to be received.

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35. Printing apparatus as claimed in Claim 29 or Claim 34, wherein the guide comprises a transverse guide comb for guiding the printable medium to the printer head.

36. An assembly according to any of Claims 1 to 20, or printing apparatus 30 according to any of Claims 21 to 23 or 29 to 35, wherein the printable medium is heat-shrinkable plastics tubing flattened to a ribbon.

37. Printable medium with register control medium, substantially as described herein with reference to Figures 2 and 4 to 6 of the accompanying drawings.

38. Printing apparatus substantially as described herein with reference to the accompanying drawings.

30. An assembly for printing, substantially as described herein with reference 5 to the accompanying drawings.

40. A method of printing onto printable media, substantially as described herein with reference to the accompanying drawings.