GB2340980A

GB2340980A - A coded token

Info

Publication number: GB2340980A
Application number: GB9818371A
Authority: GB
Inventors: Ezio Panzeri
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-08-21
Filing date: 1998-08-21
Publication date: 2000-03-01
Also published as: GB9818371D0

Abstract

A token comprises a coding region bearing coded data to be optically machine-read, the coded data being represented as a relief pattern within the coded region. The token is preferably a coin with coding formed on the rim by parallel ridges. The coded data may be at least partially represented by spacings between the ridges or by the depth between the ridges. The ridges may be rectangular, triangular or curved-edge in cross-section and have notches in them. The coded data may be represented by two or more dimensional characteristics. The relief pattern can be in the form of bores passing through the token and the coded data may be partially represented by the spacing between the bores, the size of the bores or the shape of the bores. The token may be part of a packaging product. Preferably the coded relief pattern has error correction codes. The token may be scanned in a plurality of directions. Preferably there is a token reading apparatus which comprises a laser, a detector to detect reflected laser light, and a signal processor to read the coded data.

Description

1 2340980 TOKEN BEARING CODED DATA

This invention relates to the field of tokens. More particularly, this invention relates to the field of tokens bearing coded data.

Tokens can take many forms and have many different shape (e.g. discs, strips, bars etc). One example is that of a coin. A token can be thought of as comprising or being part of an object whose authenticity is indicated by the token. A constant problem with tokens is that of counterfeiting. As technology advances it becomes generally easier for counterfeiters to produce accurate copies of existing tokens. Accordingly, it is important that token producers constantly strive to make their tokens more difficult to copy.

An important consideration is that those features of a token that are difficult to copy should also be made readily discernible, and preferably machine-readable. As an example, the highly complex engraving used as part of printed bank notes may be extremely difficult to copy, but it is also relatively difficult to discern and in many cases an expert is needed to tell an original from a copy.

Viewed from one aspect the present invention provides a token comprising a 0 coding region bearing coded data to be optically machine-read, characterised in that c 0 said coded data is represented as a relief pattern within said coding region.

An optically machine-readable relief pattern encoding data is in practice difficult to manufacture. Accordingly, copied tokens that do not have the required relief pattern may be readily detected. The relief pattern can be considered to be analogous to a type of "bar-code", but in this case is formed with a 3-dimensional shape rather than being printed in black and white. Conventional printed bar-codes can be very easily copied whereas the relief pattern of the present invention bearing the coded data is very difficult to copy.

The ability to be able to optically machine-read the relief patter for the token greatly enhances it utility. The relief pattern may in this case be used for systems such as a coin validation or point of sale authentication.

As previously mentioned, the token could take many forms. However, the invention is particularly useful for use in systems in which the token is a coin.

2 The optically machine-readable relief pattern could be disposed at various positions on the token. However, manufacture and reading are facilitated when the coding region is on the rim of the token.

One particularly preferred form of relief pattern that may be accurately mass produced is one having the form of substantially parallel ridges. The coded data may be represented by one or more of the spacing between the ridges, the depth of the ridges or notches in the ridges. The ridges may be milled on to the token. If two or three of the representations of the coded data are used in combination to provide a 31) coding then this is harder to copy.

The ridges could have various different shapes. However, regular shapes such as a rectangular cross-section, a triangular cross-section or a curve- edge cross-section are preferred.

The relief pattern may also be in the form of bores passing through the token. Accurately drilling bores through a token is a difficult engineering task and accordingly is difficult to copy. The data may be encoded as one or more of the spacing between the bores, the size of the bores or the shape of the bores.

As previously mentioned, the token for testing authenticity may in fact represent the article itself as in the case of a coin. Alternatively, the token may be attached to or be a small portion of an article. An example of this might be the packaging of a product where a portion of the packaging could bear the relief pattern and act as an indication of the authenticity of the product. High value products that are often subject to counterfeiting, such as cosmetics, could strongly benefit from this technique.

In order to improve the robustness of the system, it is preferred that the coded data incorporates error correction codes such that damage to the relief pattern does not render the coded data unreadable. It is also preferred that the coded data be arranged in a manner in which it can be read by scanning in a number of different directions if necessary.

Viewed from another aspect the present invention provides a token reading apparatus comprising:

a laser source for directing laser light onto a coded region of a token; 3 a laser detector for'receiving laser light from said coded region of said token; and a signal processor for processing an output of said laser detector in a manner responsive to a relief pattern of said coded region such that coded data is read from said relief pattern.

Depending upon the particular type of relief pattern used the detection may be arranged to work on a line-of-site blockage principle or upon a selective reflection principle.

Viewed from a further aspect the invention provides a method of storing coded data upon a token, said method comprising the step of.. forming an optically machine- is readable a relief pattern representing said coded data within a coding region of said token.

Viewed from another further aspect the invention provides a method of reading coded data from a token, said method comprising the steps of.

4n -M directing laser light from a laser source onto a coded region of a token; receiving laser light with a laser detector from said coded region of said token; C and processing an output of said laser detector with a signal processor in a manner responsive to a relief pattern of said coded region such that coded data is read from said relief pattern.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 illustrates a token havina a relief pattern; 1 C1 Figure 2 illustrates a token in which the spacing between ridges encodes the data; Figure -3) illustrates a token having bores throu h the token encoding the data; 9 and Figure 4 illustrates a rim having ridges encoding the data using a combination of techniques.

Fiaure 1 shows a token 2 in the form of a coin. Part of the rim of the coin bears a series of substantially parallel ridges. The ridges could, if desired, extend around the complete periphery of the token 2.

4 The distance between ridges is signified by the parameter X. The depth of the groove between ridges is signified by the parameter Y. The length of the ridges is signified by the parameter Z.

An apparatus such as that described in PCT Patent Application Number PCT/IB97/00569 may be used to read the dimensions of the token 2 with great accuracy. The above mentioned coin reader can measure the distance between ridges X, the depth of ridges Y and the thickness of the coin Z. A series of these measurements can be derived for the coin as it passes the sensor within the above mentioned coined reader. These dimensions can then be subject to decoding in a manner similar to that used in existing bar-coding techniques such as the USS System, C> 1= Code 39 and the like.

Figure 2 illustrates a token 2 in which the distance between three successive ridges is indicated respectively as a, b and c. These distances when measured C represent digital coded data. The data can be an authentication code (or identification code) for a coin or may include other data such as the date and place of manufacture if desired.

Figure 3 illustrates an alternative type of relief pattern that may be used. In this case, the relief pattern is in the form of bores through the thickness of the token.

Such micro-bores are difficult to fabricate and so difficult to copy. The size, shape and distance between the bores may be used to encode data. The sensor system described above may be used to read the bores of the token of Figure 31.

The coded data borne by the tokens can include start codes at either end to enable the token rim to be scanned in either direction. In this way, the orientation of the token when placed into the reader mechanism has no effect upon the ability to read the code.

In addition, error correcting codes may be included within the coded data such that if the relief pattern is partially damaged, then the code can still be read.

Figure 4 illustrates a portion of a rim of a coin in more detail. Figure 4 could :P 1 also be a representation of a token in the form of a strip or bar that was attached to the packaging of a larger product. In this example, the distances between ridges Xa, Xb 1= Z 0 and Xc can be used to encode one part of the data. The height of different ridges Ya and Yb can be used to encode further data, and finally notches cut within the ridges Za, Zb, Zc and Zd can also be used to encode data.

Whilst the distance between and height of the ridges may be directly read using the coin sensing mechanism as described in the above mentioned PCT patent application, the reading of the notches on the ridges can require an additional laser light source and sensor. This laser light source can be made to illuminate the edge of tz the coin at an oblique angle and the additional sensor be arranged to detect characteristic reflected patterns of laser light from different sizes and types of notch.

It will be appreciated that whilst the depths of the grooves could be varied, one factor that must be borne in mind is that the coin should be able to smoothly roll along 0 a coin guiding track without undue irre ularities on its rim causing it to jump. Such Z5 9 smooth rolling facilitates the reading of the fine detail in the ridges on the rim of the coin. In order to achieve this, it has been found desirable that at least half of the ridges have the same depth (distance from the centre of the coin to their outer tip) in n order that the coin should smoothly roll along a coin guiding track.

It will be appreciated that the ridges can have other forms than the rectangular 0 C (including possibly square) form as illustrated in the drawings. In particular, the C> ridges could have a triangular cross-section or a curved (e.g. sinusoid or scalloped) cross-section. Providing the dimensions of the coin can be sufficiently accurately measured, many different possible relief patterns may be employed to encode the data for authentication and other purposes.

Whilst the above examples relate to tokens in the form of coins, it will be appreciated that tokens may be provided that are not coins. As an example, a high r-> value product, such as a cosmetic, may be provided with packaging having a portion t5 t> bearing a relief pattern giving an authentication code for the product. Such a 1 relatively complex form of packaging is difficult to counterfeit and so may provide a reliable machine-readable authentication technique for the products concerned.

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Claims

1 A token comprising a coding region bearing coded data to be optically machine-read, characterised in that said coded data is represented as a relief pattern 10 within said coding region.

2. A token as claimed in claim 1, wherein said token is a coin.

3. A token as claimed in any one of claims 1 and 2, wherein said token has a rim 15 and said coding region is said rim.

4. A token as claimed in any one of claims 1, 2 and wherein said relief pattern is at least partially in the form of substantially parallel ridges.

5. A token as claimed in claim 4, wherein said coded data is at least partially represented by spacing between said ridges.

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6. A token as claimed in any one of claims 4 and 5, wherein said coded data is at least partially represented by depth between said ridges.

7. A token as claimed in any one of claims 4, 5 and 6, wherein said coded data is at least partially represented by notches in said ridges.

8. A token as claimed in any one of claims 4 to 7, wherein said ridges are milled 30 on to said token.

9. A token as claimed in any one of the preceding claims, wherein said coded data is represented by two or more different dimensional characteristics of features within said relief pattern.

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10. A token as claimed in claim 9, wherein said coded data is represented by three different dimensional characteristics of features within said relief pattern.

11. A token as claimed in any one of claims 4 to 8, wherein said ridges have a rectangular cross-section.

12. A token as claimed in any one of claims 4 to 8, wherein said ridges have a triangular cross-section.

13. A token as claimed in any one of claims 4 to 8, wherein said ridges have a curved-edged cross-section.

C1

14. A token as claimed in any one of the preceding claims, wherein said relief pattern is at least partially in the form of bores passing through said token.

15. A token as claimed in claim 14, wherein said coded data is at least partially represented by spacing between said bores.

16. A token as claimed in any one of claims 14 and 15, wherein said coded data is at least partially represented by size of said bores.

17. A token as claimed in any one of claims 14, 15 and 16, wherein said coded data is at least partially represented by shape of said bores.

18. A token as claimed in any one of the preceding claims, wherein said token is part of product packaging.

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19. A token as claimed in any one of the preceding claims, wherein said relief pattern represents said coded data in a form having error correction codes such that said coded data may still be recovered even if said relief pattern is partially unreadable.

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20. A token as claimed in any one of the preceding claims, wherein said relief pattern represents said coded data in a form that may be optically read by scanning through said relief pattern in a plurality of directions.

21. A token reading apparatus comprising: 10 a laser source for directing laser light onto a coded region of a token; a laser detector for receiving laser light from said coded region of said token; and a signal processor for processing an output of said laser detector in a manner responsive to a relief pattern of said coded region such that coded data is read from said relief pattern.

22. A token reading apparatus as claimed in claim 19, wherein said token has a form as claimed in any one of claims 1 to 18.

23. A token reading apparatus as claimed in any one of claims 19 and 20, wherein C> at least a portion of said laser detector is arranged to detect whether a line-of-sight between said laser source and said laser detector is blocked by a part of said relief pattern.

24. A token reading apparatus as claimed in any one of claims 19, 20 and 2 1, wherein at least a portion of said laser detector is arranged to detect laser light that is reflected by a part of said relief pattern.

25. A method of storing coded data upon a token, said method comprising the step 0 of.. forming an optically machine-readable a relief pattern representing said coded data tn within a coding region of said token.

:1 1=

26. A method of reading. coded data from a token, said method comprising the steps of:

directing laser light from a laser source onto a coded region of a token; c CI 9 receiving laser light with a laser detector from said coded region of said token; and processing an output of said laser detector with a signal processor in a manner responsive to a relief pattern of said coded region such that coded data is read from said relief pattern.

27. A token substantially as hereinbefore described with reference to the accompanying drawings.

28. A token reading apparatus substantially as hereinbefore described with reference to the accompanying drawings.

29. A method of storing coded data upon a token substantially as hereinbefore described with reference to the accompanying drawings.

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30. A method of reading coded data from a token substantially as hereinbefore C described with reference to the accompanying drawings.