The present invention relates to a method, according to the preamble to Claim 1, for determining the mutual compatibility (i.e. affinity) of components to be connected to each other.

According to such a method, at least one of the components is equipped with a security marking. In Europe, ever year counterfeit products cause losses to the owners of the intangible rights in original products. Fake technical products are also potentially dangerous to users.

Connected to a functioning device, for example, as a component or an accessory of the device, they can lead to operating disturbances and accidents. A counterfeit component in, or an accessory to an electronic device can abnormally overheat the device; a counterfeit electronic-device component can also cause short-circuits. These can lead, in turn, to explosions or fires. A counterfeit technical device or its fake component or accessory can cause serious injury to the user, such as burns, or even blindness.

To distinguish genuine products from counterfeit products, the sales packages and cases of products are typically equipped with security markings. These are based on, for example, optical detection (such as using holograms) or on magnetic/electrical detection (RFID elements, conductive areas). Forging such security markings is difficult and expensive, which significantly increases the price of a fake. Security markings are attached not only to sales packages, but also to the actual product, for example, to the CD-ROM disc of a computer program.

Although traditional security markings assist wholesale traders in removing fakes from the distribution chain and correspondingly the consumer in distinguishing a counterfeit product from a genuine one when purchasing it, they do not, however, entirely remove the danger that, for example, a counterfeited spare part or accessory for a technical device will be used despite detection. The present invention is intended to create a new type of solution to ensure the

functionality of a device totality, which consists of two or more components, at least one of which components of the device is typically replaceable, and the full compatibility of which with the other components of the device totality is essential for the safe use of the device totality.

The invention is based on the idea that, in order to determine the mutual compatibility of at least two components connected to each other, at least the first component is equipped with a three-dimensional piece, which is able to change its shape due to the effect of heat, voltage, an electric or magnetic field, electromagnetic radiation, or an external force (e.g., a mechanical force) - or a combination of these. Such a three-dimensional piece comprises most suitably a metallic alloy, which is able to change shape, for example, in a lattice structure, through changes taking place due to external forces. For its part, at least one other component, preferably to be connected to the above component, is equipped with an energy source, such as a control element, which is able to produce a voltage, an electric or magnetic field, heat, an electromagnetic effect, or a combination of these, or of some other force, such as a mechanical force. When the first and second components are brought into the immediate vicinity of each other, and when the control element of the second component is used to direct to the metal- alloy piece of the first component a voltage, an electric or magnetic field, heat, an electromagnetic effect/radiation, some other force, such as a mechanical force, or some combination of these, the three-dimensional shape or magnetic properties of the security- marking piece change, when, if the change exceeds a predefined limit value, the compatibility of the components can be determined.

The invention also achieves the use of a memory metal as a security marking. More specifically, the method according to the invention is principally characterized by what is stated in the characterizing portion of Claim 1.

The use according to the invention is, in turn, characterized by what is stated in Claims 19 and 21. Considerable advantages are gained by means of the present invention. Thus, by using as a security-marking piece manufactured from a memory metal, the genuineness of a product being examined can be determined both optically and mechanically; which is not possible in the case of conventional optical security markings. The change in the mechanical shape of the security marking or the change in its magnetic properties can be further exploited to create an operation or function. It can be used, for example, to open a lock or connect a power circuit. The operation or function can be a precondition for the use of the product, which prevents the use of a counterfeit product in a selected application. Being an active security marking, it also differs from conventional security markings, which are typically passive.

In a particularly preferred embodiment, the movement of a memory metal can be exploited in a way that triggers the functional connection of the component equipped with the security marking to another component. An example is a case, in which the actual operation or function demands the replacement of a worn-out part with another (e.g., an ink cartridge in a printer), in which case the receiving station in the device is equipped with a lock or an openable circuit and the replacement component is equipped with a security marking consisting of a memory metal, which is able through its deformation to act as a key, which opens the lock of the reception station and/or switches on power in the circuit.

In the following, the invention is examined more closely with the aid of a detailed description. As stated above, with the aid of the invention a method is created, by means of which is it possible to determine whether two components that can be connected to each other really do belong together. This determining of the 'mutual compatibility' of the components includes an examination of the e.g., mechanical, electrical, and/or functional compatibility of the components. Alternatively - or preferably in addition to these properties - the compatibility of the origin of the components is examined, i.e. are they from the same manufacturer or supplier, or have the suppliers a mutual authorization relationship? This latter examination represents the determining of the genuineness of, for example, a spare part or accessory. According to the invention, the first component is equipped with a three-dimensional security-marking piece, which is able to change its shape due to the effect of a magnetic field, heat, electromagnetic radiation, or a combination of these. The size of the piece is typically: length 0.01...100 mm, thickness 0.01 - 100 mm, and height 0.01 - 100 mm.

The second component, which can be connected to the first component, is equipped with an operating element, which is able to produce an energy effect in the form of voltage, an electric field, a magnetic field, heat, or electromagnetic radiation, or other external force, or a combination of these. The first and second components are brought into the immediate vicinity of each other, and, by means of the operating element of the second component, an energy effect is directed to the security-marking piece of the first component in order to change its three-dimensional shape.

In an alternative embodiment, a change is created in the magnetic properties of the security-marking piece, particularly a metallic- alloy piece (see details below), with the aid of an external force. Such an external force can be produced, for example, by means of screw threads, or even by pushing by hand.

The deformation described above is defined, and the components are determined to be compatible, if the change in the shape of the security-marking piece exceeds a predefined limit value. Particularly with memory metals (MSM materials), this deformation also causes a change in the magnitude and/or direction of the magnetic field, which can thus be exploited in determining and/or creating operations or functions, for example, with the aid of 'triggering'.

In the following, the security-marking piece is also referred to by the term 'metal-alloy piece', which is used especially to refer to a preferred embodiment, in which the security- marking piece is a memory-metal or similar metal-alloy piece. However, the explanation should not be understood a way that would restrict the features described below to precisely this embodiment, even though it represents a very good solution.

It should also be stated about the above that the concept 'able to be connected to a first component' includes in general all cases, in which a first and a second component are connected to each other. The first component can also be able to be connected to a second component. This is the case, for example, in the solution referred to above, in which a replaceable ink cartridge of a print is equipped with a security marking that permits the ink cartridge to operate in the printer. Particularly preferably the security-marking piece, such as a metal-alloy piece, is permanently attached to the first component. The term 'permanently attached' refers to, among other things, the fact that the security-marking piece cannot be separated from the first component, without a permanent trace of the security-marking piece remaining in the component.

According to a preferred embodiment, the second component is equipped with an energy source or an operating element, which produces a voltage, magnetic or electric field, or electromagnetic radiation, or heat, or a combination of these. In one embodiment, the operating element is a permanent magnet or electromagnet, for example, a suitable coil, which is able to produce magnetically a deformation in a metal- alloy piece (memory metal). In a second embodiment, the operating element is a thermal resistance, a Peltier element, a thermal radiator, or similar heating element, which is able to warm or heat a metal-alloy piece. In order for the energy source of the second component to be able to create the desired effect, it must generally be brought sufficiently close to the metal-alloy piece. In one embodiment, it is brought into contact with the metal-alloy piece. In a second embodiment, the distance between the energy source and the metal-alloy piece is about 0.01 - 100 mm, most suitably 0.1 - 50 mm.

As a result of the energy produced in the metal-alloy piece, the shape of the piece changes, as a result of the changes taking place in its lattice structure. The magnitude of the change in a single dimension is generally in the order of a few percent; the change is, for example, about 0.01 - 20 %, most suitably 0.1 - 15 , calculated from one dimension, for example the length, of the piece.

In the case of metal alloys, such as memory metals, it is preferable to direct a magnetic field, which has a strength of about 0.0001 - 1 T, to the metal-alloy piece. The temperature effect will generally be sufficient, if the temperature of the piece can be raised from the ambient temperature to the austenite temperature, or slightly above it.

In one embodiment, the change in the shape of the metal-alloy piece is determined mechanically, electrically, magnetically (e.g., using a Hall sensor), or by combining these techniques, for example, mechanically and electrically.

In order to determine the change in shape, the metal-alloy piece connected to the first component is arranged in such a way that, in the state in which its shape has been changed by the effect of a voltage, an electric or magnetic field, heat, electromagnetic radiation, an external (mechanical) force, or a combination of these, the metal-alloy piece creates an operation or function.

The second component can be, for example, a machine or device, which is equipped with a receiving station, into which the first component can be placed, in which case only a component that has been determined to be genuine will permit the basic operation of the machine or device.

In one embodiment, the components together form a device structure, which has a preselected operation or function, in which case the three-dimensional metal-alloy piece is arranged in such a way that, in the state in which its shape has been changed by the effect of a voltage, an electric or magnetic field, heat, electromagnetic radiation, an external force, or a combination of these, the metal-alloy piece permits the said operation or function.

In another embodiment relating to this embodiment, the metal-alloy piece triggers the operation or function, when it moves to a deformation state.

The change in the shape of the metal-alloy piece can also be detected by using a separate sensor. This can be, for example, mechanically, electrically, or magnetically operated.

In one particularly preferred embodiment, the connection of the first and second component is possible only if the metal-alloy piece is in a deformation state. The metal-alloy piece and the operating element form together the parts of a lock, so that the metal-alloy piece is able to open the lock. After the opening of the lock, the device is able to create the selected operation or operations. In one embodiment, one component is a machine and the other is a replaceable part, such as a spare part or an accessory. In a preferred embodiment, the replaceable part of the machine is the aforementioned first component, which is equipped with a metal-alloy piece, or a corresponding security-marking piece. The metal- alloy piece comprises most suitable a so-called memory metal. A memory metal (Shape Memory Alloy, SMA) is a metal alloy, which is able to change its crystalline structure when subject to the effect of an external force. In the case of an SMA, a temperature change generally takes martensite->austenite and back again. The change is reversible.

Most memory metals change their lattice structure between an austenitic and a martensitic state under the influence of changes in temperature. There is also a particular type of memory metal, which changes its shape due to the effect of a magnetic field. These memory metals are typically ferromagnetic (Ferromagnetic Shape Memory Alloy, FSMA). The particular advantage of these metals is that the deformations take place more rapidly and effectively from the effect of a magnetic field than through temperature changes.

According to one embodiment, the metal-alloy piece is manufactured from a magnetic memory metal, a magnetostrictive material, an SMA material, or an electroactive

(artificial-muscle) polymer.

According to a second embodiment, the security- marking piece consists of single-crystal material, a multi-crystal material, a composite material, in which case, for example, the substance comprises granules (particles, single crystals, or groups of them) and a binder, or of a thin-film material.

In a first preferred embodiment, the metal alloy consists of an NiMnGa alloy, which possibly contains one or more additional metals, which are, for example, Co, Fe, Cu, In, or Sn. Such a material will change its shape and crystalline structure due to the effect of a magnetic field.

In a second preferred embodiment, the metal alloy piece consists of Terfenol (TbDyFe), Galefenol (FeGa), or Nitinol (NiTi). Terfenol ja Galfenol are other examples of metal alloys that change shape due to the effect of a magnetic field - they are so-called magnetostrictive products, which same group also includes an iron-palladium alloy (FePd). For its part, Nitinol is an example of a material that changes due to the effect of heat. The above description is mainly of ways, by means of which the dimensions of a security- marking piece can be affected magnetically or electrically, or by electromagnetic radiation, or by a combination of these. In a second solution of the invention, a phenomenon is exploited, in which a change in the shape of a piece, created by an external force, also leads to a change in the magnetic, or generally the 'electromagnetic' properties of the piece. Thus, by means of an external force, it is possible to create a change of, for example, as much as 20 %, particularly about 0.01 - 15 % in at least one dimension of a piece, in which case the magnetic field of the piece will be made to rotate by as much as 90 degrees.

For example, the piece can be compressed or stretched. Such a force effect can be achieved by pushing or rotating the second component against the security-marking piece of the first component. If desired, a mechanical force can be directed to the piece, which alters it in a different way and to a different extent in different dimensions.

The change in electromagnetic field, for example a change in magnetic field, that then takes place in the piece, can be detected using a sensor, or as a rotational moment in the magnetic field running through the piece. If an external effect, electricity, heat, a magnetic field, radiation, or other external mechanical force, is directed to the piece, the change in magnetic properties will cause rotation in the magnetic elements along with the lattice axes.

In the second piece, a change in the direction of the magnetic field can be changed into a movement, which can be used to drive an operating device relating to the device totality, for example, it can be used to open and close a locking mechanism in the device. Thus, based on the above, a metal-alloy piece manufactured from a memory metal can generally be used as a security marking suitable for determining a product's genuineness.

The present solution is suitable for use in, among others, the following applications:

electronic products, such as mobile telephones and their parts and accessories, audio and video devices and their parts and accessories, computers and their parts and accessories, printers and their parts and accessories, domestic appliances and their parts and accessories, vehicles and their spare parts and accessories, lighting fittings and their parts and accessories, air-conditioning devices, ventilators, and fans and their parts and accessories, devices and means intended for health and sickness care as well as their parts and accessories, security devices, such as locks and keys, weapons and ammunition, as well as filtering devices and their parts and accessories.

In one embodiment, the key to a lock is equipped with a piece consisting of a memory metal (MSM), which activates the lock. If the lock does not detect the MSM piece, it refuses to open, no matter whether the key is otherwise correctly cut. This solution can be used to prevent the trivial copying of a key.

Particularly advantageously, a security marking, particularly a metal-alloy piece manufactured from a magnetic memory metal, can be used in an ink-jet cartridge, a colour cartridge, a gas bottle, a lock or key, a computer or mobile-telephone battery, computer or mobile-telephone charges, incandescent lamps, fluorescent lamps and other mercury- vapour lamps, LED lamps, neon and other discharge lamps, high-pressure sodium lamps, sulphur-plasma lamps, pharmaceutical-dosing devices, as well as in air filters.