Such a coin or token is generally known in the state of the art. An image is formed with the aid of a relief. Such a relief can be provided with grey tints by producing the composition of the image using dots applied more or less densely.

In the case of currencies the aim is to apply as many security features as possible in a currency such as a coin. After all, it has been found that in the longer term the majority of security features can be counterfeited but that as a result of a combination of a large number of features it is not very attractive to a potential counterfeiter to proceed with reproduction.

A coin that, for example, is provided with a hologram or kinegram is described in the document"Munze mit einem optischen Sicherheitselement (Coins with an optical security element) ", 1 June 1995 (1995-06-01), Research Disclose, Kenneth Mason Publications, Hampshire, GB, p. 415 XP000519446 ISSN: 0374-435.

In the state of the art it is generally known to print bank notes with a wide variety of types of patterns.

Therefore, the aim of the present invention is to provide a coin/token with a further security feature.

According to the present invention this aim is achieved in that said image is composed of a number of essentially identical characteristics which extend beyond said image and wherein said characteristics at the location of said image have a different intensity to those next to said image.

In contrast to the state of the art described above, where an image is composed by changing the intensity of dots, according to the present invention it is proposed to compose the various features using characteristics.

According to an advantageous embodiment of the invention, the depth of the engraving, that is to say the difference between"high"and"low", is at least 0.03 mm. This value is higher than the differences in height found with coins that are provided with grey tints.

Characteristics are understood to be lines, letters, numbers, symbols, repetitive figures, characters and the like. According to the present invention these characteristics are applied with a greater or lesser degree of accentuation depending on the location on the

coin. The desired image is produced by applying a large number of characteristics that are accentuated (have a different intensity) to a greater or lesser extent. This accentuation can be obtained in any manner known in the state of the art. For instance, it is possible with the technique described above where dots are used to use a greater or lesser intensity of dots to obtain a more accentuated or less accentuated characteristic. It is also possible to vary the "line thickness". Moreover, the height thereof can be varied. When using characters it is also possible to vary the size of the characters. A lighter pattern is obtained with a smaller size. In this case the number of characters per unit surface area does not change. It is, of course, also possible to allow the number of characters to change and to produce a lighter or darker tint in this way.

If a number of lines arranged alongside one another is used, it is possible to position these lines closer to one another (more intensively) in some locations than in other positions.

According to a further advantageous embodiment, the so-called latent image technique is used for the coin/token concerned. That is to say the various features are composed of lines, characters or the like that extend in two directions which preferably cross perpendicularly. All sorts of light effects can be obtained by this means.

The repetitive characteristics applied in a regular manner can either be present in the master die or applied exclusively in a later working step in the working die. The latter will be the case in particular if the characteristics are produced with the aid of laser techniques.

In such a case the master die will not contain the characteristics.

The characteristics are applied in accordance with a regularly repeating pattern. In the case of lines, the lines can be applied as undulating lines and the distance between the lines can vary depending on the position.

In contrast to the publications known in the state of the art for applying specific patterns to bank notes, the present invention relates to the application of reliefs to coins.

Such a relief has a difference in height compared with the base material of 5-20 p and more particularly approximately 10 Il. These reliefs are so chosen that a visible image is produced on the coin.

The invention also relates to the production of an image on the edge of a coin/token.

In the state of the art after the blank has been punched this is provided with an edge image, after which the final image is then applied to the front and back of the coin/token.

It is now proposed to produce the coin in full and only then to produce the edge

image. This applies more particularly for images that are composed of line patterns or characters. In such a case a die is provided along which the coin rolls. Such an edge impression with grey tints constitutes a further security feature. It must be understood that in principle the step for the production of an edge image with grey tints is independent of the composition of an image by means of characteristics which has been described above, that is to say can be used with any other method for the production of images on coins.

The invention will be explained in more detail below with reference to an illustrative embodiment shown in the drawing. In the drawing: Fig. 1 shows a coin according to the invention provided with an image; Fig. 2 shows a detail of Fig. 1; Fig. 3 shows an alternative for characteristics; Fig. 4 shows the composition of a latent image; and Fig. 5 shows, diagrammatically, a method for the production of an edge image on a coin.

In Fig. 1 a coin is indicated in its entirety by 1. An image thereon is indicated diagrammatically by 2. The composition of this image with respect to the adjacent part of the coin can be seen from the detail in Fig. 2. From this it can be seen that the various features are composed of undulating lines 3 of varying thickness and varying spacing. An image can be obtained by applying these lines in a suitable manner. According to the invention the image is preferably built up exclusively by variations in the characteristics such as the lines 3. An alternative for the characteristics is shown in Fig. 3 and consists of letters 4. It will be understood that other symbols can be used to obtain such characteristics.

According to a particular embodiment the characters can be combined or partially consist of lines that cross one another. This is shown in Fig. 4. Here the characters according to the present invention consist of horizontal lines 5. There is also an undulating pattern. A specific structure can be built up by applying vertical lines 6.

A method for the production of an edge image on a coin 1 is shown diagrammatically in Fig. 5. After the coin has been fully produced (with the exception of the edge image) it is rolled over a die 7 and an edge image is obtained there. The die is designed to transfer line patterns or characters to the edge of the coin so that it is not a simple stamping that is produced but an image of complex composition.

Although the invention has been described above with reference to preferred embodiments, it will be understood that numerous modifications can be made thereto without going beyond the scope of the present application. Numerous other characteristics are possible in order to differentiate an image with respect to the surroundings. These and further variants fall within the scope of the appended claims.