GB2370249A

GB2370249A - Method of printing an image onto a low contrast substrate

Info

Publication number: GB2370249A
Application number: GB0026975A
Authority: GB
Inventors: Graham Podmore
Original assignee: Zipher Ltd
Current assignee: Videojet Technologies Nottingham Ltd
Priority date: 2000-11-04
Filing date: 2000-11-04
Publication date: 2002-06-26
Also published as: GB0026975D0

Abstract

A method of printing a first print medium onto a low contrast substrate, e.g. cardboard box 10, comprises the steps of printing a region 14 of the substrate with a second print medium, and then printing an image 16, e.g. a bar code 18, over the printed region 14 using a first print medium, wherein the second print medium contrasts the first print medium. Also disclosed is a pack for packaging, wherein the pack has at least one low contrast panel which comprises an image printed according to the method above. Preferably the second print medium comprises a reflective ink, or one of red and white ink. The first print medium may comprise low reflectivity ink, or black ink. The time delay between applications of the print mediums is preferably less than five minutes, and more preferably less than one minute. The use of contrasting inks results in higher bar code scan grades.

Description

Method of Printing

This invention relates to a method of printing onto distribution units such as cardboard boxes, and in particular to a method that utilizes a two-stage printing process especially in order to deliver high contrast images on corrugate substrates, such high contrast being a key factor in the

reliable scanning/reading of barcodes.

The use of barcodes within the distribution and supply chain is now commonplace. In particular, retailers and distribution organisations derive value from the printing of barcodes onto outer cases or transit packs (often known as"traded units"). Typically, these are cardboard boxes or cardboard trays covered in a shrink-wrap film. These barcodes typically describe the identity and manufacturer of the goods inside the traded units, as well as other information.

Historically, such barcodes have been pre-printed onto the cardboard boxes or trays (often known as"packs") by the packaging materials supplier (often known as"the converter") at the time that they are die cut, before they are delivered to the goods manufacturer. Because of the typically large variety of barcodes used by any one manufacturing factory, this often results in high costs of storage of large volumes of these pre-printed boxes. The use of pre-printed packaging can also give rise to inflexibility in the manufacturer's production operation.

A number of existing technologies have been employed to offer a"print on-demand"or"print on-line"capability. The intention is to substantially reduce the number of packs that a factory needs to store and to print the barcodes and other data as part of a production batch run, rather than such information being pre-printed. This also offers improvements in production flexibility.

One successful technology is"Print and Apply Labelling", in which plain white labels are printed then applied to plain packs as part of the production process. Unfortunately, the running costs, including labels and ink, as well as machinery upkeep and maintenance, of such a print and apply system are quite high.

Another known art is the use of a photo-sensitive ink which can be used to print a"receptor patch"onto a plain pack, either during the production process or beforehand. In this art, a laser is typically employed during the production process to energise the photo-sensitive ink in such a

way as to form an image of barcodes and text. Whilst this art promises a lower running cost than print and apply labelling, it has not yet been commercially successful. fA t.

Another known art is ink jet printing, in which images are printed directly onto the essentially plain pack, during the production process. This art too promises a substantially lower running cost than Print and Apply Labelling, however it has, to-date, suffered from poor contrast images, which give rise to poor bar code read rates. The poor contrast is due to the nature of the cardboard packs themselves, rather than the density or quality of the ink jet printed image.

Furthermore, this problem also applies to another known art in which ink is directly printed onto the pack by a Thermal Transfer process, in which the ink is melted away from a carrier and onto the cardboard substrate of the pack. The resultant image itself is a dense black print, but again the image is of a low contrast with respect to the cardboard substrate of the pack.

For environmental and cost reasons, such trays and cases are usually constructed from brown coloured materials such as test liner or Kraft. However, the poor reflectance characteristics of such materials, with respect to the light source of typical bar code readers (scanners), has a direct impact on the quality ofabarcode that is printed on these materials.

Bar code quality is measured using the CEN or ANSI standards, which are a weighted average of a number of quality measurements, one of which is related to symbol contrast ie the reflectance of the printed bars versus the reflectance of the background material.

The best quality barcode image would produce an ANSI Grade A, however, barcodes printed directly onto brown cardboard boxes typically only achieve an ANSI grade D, which is on the border of acceptability for many scanning systems. When the ANSI analysis is investigated in depth, it can be seen that the poor reflectance of the brown cardboard, with respect to the light source of the bar code scanner, is the limiting quality factor, which cannot be improved upon by the barcode printing process itself.

It is an object of this invention to provide a means of substantially improving the contrast quality of images, especially barcodes, which are printed by any of the above-mentioned or other techniques, directly onto packs, cardboard or other surfaces exhibiting similar poor reflectivity.

It is a further object of this invention to provide a means which is low cost and which does not require the use of photo-sensitive inks or the like, so that the running costs remain very

favourable compared to existing arts, as well as removing the costs associated with the storage of large varieties of pre-printed packs.

According to a first aspect of the invention, there is provided a method of printing a first print medium onto a relatively low contrast substrate comprising the steps of printing a region using a second print medium which medium contrasts with the first print medium, and then printing an image using the first print medium over the printed region.

(Note to client: further statements of invention to be including upon agreement of the format of the claims at the end).

An example of the invention will now be described, with referenced to the accompanying drawings, wherein; Figure 1 is a schematic view of a pack which is produced during a first stage of printing according to the invention; and Figure 2 is a schematic view of a pack produced according to the invention.

The first stage of the method according to the invention is the printing of a white panel or similarly reflective panel or region (with respect to the light source of a barcode scanner, for example a laser scanner, for example a red panel or other reflective colour or ink) onto the pack.

The size of the printed panel is preferably kept to a minimum. The panel is preferably printed slightly larger than the size of the intended image such as a barcode. The location of the printed panel is preferably defined as follows with referenced to Figure 1.

Figure 1 shows a pack 10 such as a cardboard box comprising a side panel 12 and having printed

thereon a printed panel or printed region 14. The location of region 14 is dimension DIA above the bottom edge of panel 12 and dimension DIC from the side edges of panel. Region 14 itself has dimensions of a width DID and height DIE. Preferably dimension DIA is greater than 20mm and more preferably in the order of 30mm. Preferably dimension D1C is greater than 15mm and more preferably greater than 19mm. Typically region 14 has a height D1B greater than 20mm and preferably in the order of 30mm, and a width DID greater than 100mm and typically in the region of 170mm.

It may be that more than one barcode is required on a side or on mulitlpe sides of a pack or trade unit, in which case the relevant number of printed regions or reflective panels are printed. These panels are printed using inks and printing processes typically employed in corrugate packaging printing.

The second stage is the printing of the barcode and text image. In this stage, the position of the second printed image, or if multiple images are required, a second set of printed images, is arranged to coincide, within normally acceptable production tolerances, with the position of the first stage printed panel, so that the second stage image is printed essentially on top of the first stage image or printed region as shown in Figure 2.

The result is a printed image of higher contrast than known in the art, due to the contrast between the first and second stage prints. This results in higher barcode scan grades being attained, to a level which is commercially viable for use in barcode printing and subsequent scanning and identification of packs of goods throughout the supply chain.

The first stage printing of the panel can be done at any time prior to the second stage printing operation. For example, it could be printed by the packaging converter at the time the packs are manufactured, or it could be printed"on-line"immediately prior to the second stage printing operation (such as within 5 minutes or 1 minute of printing the barcode), or at any stage in between.

The panel and subsequent image is typically printed on one, several or all of the sides of the pack, and normally is located near the bottom edge of the box, but its bottom edge will typically be around 30mm from the bottom edge. Its vertical edges is not normally closer than 19mm to any vertical edge of the box or tray, and a panel's width is normally a maximum of 170mm and its height around 30mm.

In particular, with reference to Figures 1 and 2 the following criteria preferably apply. As can be seen from Figure 2, an image region 16 is shown in dotted outline which, is printed on top of first region 14. Second printed region 16 preferably comprises a barcode 18 wherein the second printed region 16 is preferably entirely overlapping with the first region 14. Accordingly, image 16 has a height D2B, wherein D2B is preferably less than DIB and a length D2D which is preferably less than DID. Preferably either one or both of dimensions D2B and D2D of image 16 is 10% and more preferably 5% less than the equivalent dimension of region 14. Alternatively, printed region 14 can be defined by an area Al and image 16 can be defined by an area A2 (as shown in figures 1 and 2) wherein the area A2 is less than the area Al preferably by approximately 10% and more preferably by approximately 5%.

Claims

1. A method of printing a first print medium onto a low contrast substrate comprising the steps of printing a region using a second print medium which medium contrasts with the first print medium, and then printing an image using the first print medium over the printed region.

2. A method of printing according to Claim 1 wherein the second print medium comprises a reflective ink.

3. A method of printing according to Claim 2 wherein the second print medium comprises one of white and red ink.

4. A method of printing according to any preceding claim wherein the second print medium does not comprise a photo sensitive ink.

5. A method of printing according to any preceding claim wherein the first print medium comprises a low reflectively ink.

6. A method of printing according to Claim 5 wherein the first print medium comprises black ink.

7. A method of printing according to any preceding claim wherein the printed

region is larger than the image.

,

8. A method according to Claim 7 wherein the image has a width which is less than the width of the printed region.

9. A method according to Claim 8 wherein the width of the image is about 10% less, and more preferably about 5% less, than the width of the printed region.

10. A method of printing according to any of Claims 7, 8 or 9, wherein the image has a length which is less than the length of the printed region.

11. A method of printing according to Claim 10 wherein the length of the image is less than about 10%, and more preferably less than about 5%, of the length of the printed region.

12. A method of printing according to any of Claims 7 to 11 wherein the area defined by the printed region is preferably about 10% and more preferably about 5%, greater than the area defined by the image.

13. A method of printing according to any preceding claim wherein the image is printed entirely within the area of the printed region.

14. A method of printing according to any preceding claim wherein the printed region is more than about 20mm, and preferably more than about 30mm from a bottom of the edge of the substrate.

15. A method of printing according to any preceding claim wherein the printed region is printed a distance of more than about 10mm, and preferably more than about 19mm, from any side edge of the substrate.

16. A method of printing according to any preceding claim wherein the substrate comprises a corrugated material such a cardboard.

17. A method of printing according to any preceding claim wherein the time delay between printing the printed region and printing the image is less than 5 minutes.

18. A method of printing according to Claim 17 wherein the time delay is less than 1 minute.

19. A pack for packaging items, comprising at least one panel of low contrast material having-an image comprising a first print medium printed over a printed region comprising a second print medium, wherein the first print medium contrasts with the second print medium thereby facilitating easy recognition of the image on the printed region.

20. A pack according to Claim 19 wherein the second print medium does not comprise a photo sensitive ink.

21. A pack according to Claim 19 or 20 wherein the second print medium comprises one of a white and a red ink.

22. A pack according to any of Claims 19 to 21 wherein the first print medium comprises black ink.

23. A method of printing substantially as described herein with reference to the example.

24. A pack substantially as described herein with reference to the drawings.