IE48093B1

IE48093B1 - Printed documents

Info

Publication number: IE48093B1
Application number: IE642/79A
Authority: IE
Original assignee: Bradbury Wilkinson & Co
Priority date: 1978-04-11
Filing date: 1979-08-08
Publication date: 1984-09-19
Also published as: MTP844B; DE2914831A1; IE790642L; NL7902472A; GB2018197A; GB2018197B

Abstract

A method of printing bank notes, cheques &c., involves incorporating a word and/or design into the printed matter, both the word and/or design and the surrounding area comprising a plurality of continuous lines. The lines forming the word and/or design are at an angle to the lines forming the surrounding area. Also the width and spacing of the lines are selected so that the word and/or design is not readily visible in the document but is readily visible in a copy of the document made on a copier employing a light source for scanning the document.

Description

This invention relates to printed documents. More 5 particularly the invention relates to a method of printing a document in a manner which produces an authenticated document, for example a security document, of which copies are visually distinguishable from the' original document.

The problem of copying security documents has been accentuated by the advent of the colour copier which involves a light source scanning the original document which are sufficiently similar to the original document to be usable for fraudulent purposes.

To counter this copying technique it has been proposed to introduce some word or sign such as the in the original document but is readily visible word VOID which is not readily visible/ in any copy produced on a light scanning copier, thereby clearly evidencing that the copy is not genuine. This proposal involved printing the original document by the known printing method of half tone screen dot formations. However, it has not been possible to achieve the desired effect in this manner for several reasons. One reason was the problem of registration between printing impressions. Other reasons were that fluctuations in ink density and/or the occurrence of dot gain during a printing run prevented the word VOID being sufficiently invisible on the original document.

According to the inventicn there is provided a method of printing a document caiprising incorporating into the printed matter a word and/or sign which is of such a character that it signifies that the document wiien copied may not be genuine both the word and/or sign and tiie surrounding area caiprising a plurality of continuous lines, the lines forming the word and/or sign being at an angle to the lines forming the surrounding area and the width and spacing of the lines being selected so that the word and/or sign is lj not readily visible in the document but is readily visible in a copy of the document made on a copier employing a light source for scanning the document.

Preferably the word and/or sign and the surrounding area are printed in a single impression.

It is also preferred that the colour and density 4809 3 of the print forming the word and/or sign and the surrounding area are selected to increase both the invisibility characteristic of the word and/or design on the printed document and its visibility when the document is copied. The colour of said printed matter may be any contrasting colour relative to the base material of the document.

Preferably the word and/or sign and the surrounding area are printed by offset printing or letterpress.

The lines forming the word and/or sign and the surrounding area may be straight, parallel lines or may be of curved or of irregular form.

In one embodiment of the invention the method involves a second step of overprinting or underlaying the word and/or sign and at least part of the surrounding area with further printed matter, the density and form of said further printed matter being selected to increase the invisibility characteristic of the word and/or sign but not to reduce its visibility when the document is copied, by an unacceptable degree.' Preferably said further printed matter is applied by offset printing or letterpress. · It is also preferred that said further printed matter is of a different colour to that of the word and/or » sign and the surrounding area.

If desired, said further printed matter may contain two or more different colours.

The invention also provides a document printed by a method as defined above. Preferably the document is a security document, such as a banknote, cheque, credit transfer or any other document requiring authentication of validity It is preferred that the word and/or sign incorporated into the printed document is made up generally of curved shapes and any straight portions are reduced to a minimum.

By way of example, specific embodiments in accordance with the invention will be described with reference to the accompanying diagrammatic drawings in which:Figure 1 illustrates part of a printed document Figures 2 and 3 illustrate two alternative copies of the document of Figure 1 when copied on a copier employing a light source for scanning the document; and Figure 4 illustrates part of a modified form of printed document.

It is explained that the drawings are intended only to illustrate the principles of the invention Referring to Figure 1, a document 10, for example a security document such as a banknote, cheque or other document capable of being exchanged for cash or credit, is represented, in this embodiment, by a rectangle having printed matter 11 containing a cross sign and the word VOID of whioh only the first letter V is shown. Both the cross sign and the word VOID are formed by a first series of continuous lines and the surrounding area 12 is formed by a second series of continuous lines which lie at an angle to the first series of lines.

In this embodiment each series of lines comprises lines which are straight and parallel to each other, and the first series of lines forming the cross sign and the word VOID are parallel to the short 15 sides of the document and at right angles to the second series of lines forming the surrounding area 12.

It has been found that when the document 10 is copied by a copier employing a light source for scanning the document each series of lines is reproduced to a different extent. Thus if each series of lines in the original document has the same initial strength, whereby the cross sign and the word VOID are not readily visible, when the document is copied, one series of lines of the copy will be darker than the other series of lines, thereby highlighting the presence of a cross sign and the word VOID and thus making them readily visible. This effect is illustrated in Figures 2 and 3 which show two alternative copies. The form of copy shown in Figure 2 is produced by positioning the document on the copier so that the series of lines forming the cross sign and the word VOID extend in the direction of movement of the light source during its scanning cycle thereby reproducing these lines to a greater extent than the lines forming the surrounding area 12. In contrast, in the case of the copy shown in Figure 3, the document is positioned on the copier so that the series of lines forming the surrounding area 12 extend in the direction of movement of the light source during its scanning cycle , whereby the surrounding area is copied to a greater extent than the cross sign and the word VOID.

The extent to which the cross sign and the word VOID are not readily visible in the original document has been found to depend on four principal factors, which are the choice and strength of the colour of the printed matter relative to the colour of the base materi al of the document, and the width and spacing of the lines.

On the other hand, these same factors will determine the degree to which the cross sign and the word VOID is visible when the document is copied. Thus, in practice, a combination of these factors is selected to give an acceptable invisibility characteristic of the cross design and the word VOID in the original document whilst rendering the cross sign and the word VOID readily visible when the document is copied. For example, it has been found that if the lines are too closely spaced for a given density of colour and line width, the cross sign and the word VOID will not be readily visible when the document is copied, and yet if the lines are too widely spaced, the cross sign and the word VOID are not sufficiently invisible in the original document.

By way of example, the document may have a white base material and blue printed matter, and the width of line forming both the cross sign and the word VOID and the surrounding area 12 may be within the range 0.02mm to 0.06mm, with line spacings from 0.06mm to 0.3mm, or such other combination of line widths and spacing as to achieve the effect required.

Further features may be incorporated to render the cross sign and the word VOID more invisible in the original document. For example, the lines of the cross sign and the word VOID may be disposed at an angle other than 90° to the lines of the surrounding area 12. Also, the lines may be curved or have another non-straight form. In this respect, it is found that rounded configurations are more readily rendered acceptably invisible in the original document such as in the formation of the letter 0 in the word VOID compared with the more positive corners of the cross sign and other letters of the word VOID. Furthermore, if desired, the printed matter 11 may be provided with overprinting 13 of a different colour, as shown in Figure 4. Once again, the overprinting must not be so effective in hiding the cross sign and the word VOID in the original document 10 that the cross sign and the word VOID are not readily visible when the document is copied.

The invention is not restricted to the specific details of the embodiments described above. For example, any desired word and/or sign may be incorporated into the printed matter 11 in the document instead of the cross design and the word VOID.

The main advantage achieved by this invention is' that it enables the printed matter 11 on the document incorporating the normally hidden word ana/or sign to be printed by offset printing or letterpress in a single impression. Other impressions can then be superimposed, or underlayed, to create further security and to disguise the presence of the normally hidden word and/or sign whilst not precluding the word and/or sign becoming 4809 3 readily visible when the document is copied on the form of copier described above.

Claims

CLAIMS:

1. A method of printing a document comprising incorporating into the printed matter a word and/or sign which is of such a character that it signifies that the document when 5 copied may not be genuine, both the word and/or sign and the surrounding area comprising a plurality of continuous lines, the lines forming the word and/or sign being at an angle to the lines forming the surrounding area and the width and spacing of the lines being selected so that the 10 word and/or sign is not readily visible in the document but is readily visible in a copy of the document made on a copier employing a light source for scanning the document.

2. A method as claimed in Claim 1, wherein the word and/or sign and the surrounding area are printed 15 in a single impression.

3. A method as claimed in Claim 1 or Claim 2, wherein the colour and density of the print forming the word and/or sign and the surrounding area are selected to increase both the invisibility characteristic of 20 the word and/or sign on the printed document and its visibility when the document is copied.

4. A method as claimed in any one of the preceding claims, wherein the word and/or sign and the surrounding area are printed by offset printing or letterpress.

5. A method as claimed in any one of the preceding claims, wherein the lines forming the word and/or sign and the surrounding area are straight, parallel lines.

6. A method as claimed in any one of the preceding claims, including a second step of overprinting or underlaying the word and/or sign and at least part of the surrounding area with further printed matter, 1_-, being selected to increase the invisibility characteristic of the word and/or sign hut not to reduce its visibility wuen the document is copied, by an unacceptable degree.

7. A method as claimed in Claim 6, wherein said further printed matter is applied by offset printing or 20 letterpress.

8. A method as claimed in Claim 6 or Claim 7 wherein said further printed matter is of at least one different colour to that of the word and/or sign and the surrounding area. 5

9. A document printed by a method as claimed in any one of the preceding claims.

10. A document as claimed in Claim 9, wherein the document is a security document, such as a banknote, 10 cheque, credit transfer or any other document requiring authentication of validity.

11. A document as claimed in Claim 9 or Claim 10 wherein the word and/or sign incorporated into the 15 printed document is made up generally oi curved shapes and any straight portions are reduced r.o a minimum.

12. A method of printing a document substantially as hereinbefore described with reference to the 20 accompanying drawings. A printed document substantially as hereinbefore

13. described with reference to drawings. Dated byWju 27 Hy AGENTS