阅读说明：本技术 用于存储回转或位置信息的传感器元件 (Sensor element for storing rotation or position information ) 是由 J·施奈德 W·霍扎普费尔 M·霍伊曼 于 2020-11-27 设计创作，主要内容包括：本发明涉及一种用于存储回转或位置信息的传感器元件,所述传感器元件包括畴壁导体(1)和衬底(2)。所述畴壁导体(1)的走向被构成为封闭环绕的、无交叉的并且连续的。此外,所述畴壁导体(1)包括具有正曲率的第一区域(A)和具有负曲率的第二区域(B)。(The invention relates to a sensor element for storing rotation or position information, comprising a domain wall conductor (1) and a substrate (2). The domain wall conductor (1) is formed to be closed-loop, non-crossing and continuous. Further, the domain wall conductor (1) includes a first region (a) having a positive curvature and a second region (B) having a negative curvature.)

1. A sensor element for storing rotation or position information, comprising a domain wall conductor (1; 1 ') which is arranged on a substrate (2), wherein the course of the domain wall conductor (1; 1 ') is designed to be closed-loop, non-crossing and continuous, and wherein the domain wall conductor (1; 1 ') furthermore comprises a first region (A) having a positive curvature and a second region (B) having a negative curvature.

2. The sensor element according to claim 1, wherein the domain wall conductor (1; 1') is formed as a conductor track on the substrate (2).

3. The sensor element according to any of the preceding claims, wherein the domain wall conductor (1; 1') has a width (D) of less than 1000 nm.

4. The sensor element according to any one of the preceding claims, wherein the substrate (2) has a glass layer and/or a silicon layer.

5. The sensor element according to any of the preceding claims, wherein the sensor element furthermore has a readout element (7) by means of which the local magnetization state of the domain wall conductor (1; 1') can be determined.

6. The sensor element according to claim 5, wherein the domain wall conductor (1; 1') is arranged in a layer between at least one read-out element (7) and the substrate (2).

7. The sensor element according to claim 5 or 6, wherein at least one readout element (7) is arranged in a layer between the substrate (2) and the domain wall conductor (1).

8. The sensor element according to any of claims 5 to 7, wherein the read-out element (7) is constituted as a GMR or TMR sensor.

9. The sensor element according to any of the preceding claims, wherein the sensor element has a plurality of domain wall conductors (1; 1') having a different number of first regions (A) or a different number of second regions (B).

10. The sensor element according to claim 9, wherein the different numbers of first areas (a) are coprime.

11. A storage system comprising a sensor element according to any of claims 5 to 10 and a magnetic device (3; 3 ') movable in a first direction (x; x ') relative to the domain wall conductor (1; 1 ').

12. Storage system according to claim 11, characterized in that the magnetic means (3) are constituted as a magnet array having magnets (3.1 to 3.6) whose poles are arranged offset from each other in the first direction (x).

13. Storage system according to any of claims 11 or 12, wherein the magnet array has magnets (3.1 to 3.6) whose poles are arranged offset from each other in a second direction (y), wherein the second direction (y) is oriented orthogonally to the first direction (x).

14. The memory system of any of claims 11 to 13, wherein in the first direction (X), the domain wall conductor (1) has an extension (X1) and the two poles of the magnetic device (3) have a center-to-center distance (X2), wherein the extension (X1) is smaller than the center-to-center distance (X2).

15. Storage system according to any of claims 11-14, wherein an auxiliary magnet (6.11) is arranged beside the magnetic device (3) with respect to the first direction (x).

Technical Field

The invention relates to a sensor element according to claim 1 for storing swivel or position information, for example for an angle or length measuring device.

Angle measuring devices are used, for example, as rotary encoders (Drehgeber) for determining the angular position of two machine parts that can be rotated relative to one another. For this purpose, so-called Multi-Turn angle measuring devices are often used, by means of which absolute position determination is possible over (uber … hinweg) a plurality of revolutions (Umdrehungen).

Furthermore, length measuring devices are known in which the linear displacement (Verschiebung) of two machine parts which can be displaced relative to one another is measured. In particular in the case of length measuring devices with comparatively large measuring lengths, it is customary to arrange a plurality of linear scales or identical scales in a row. In the case of such a length measuring device, it should be possible to determine the absolute position over the entire measuring length as far as possible.

Such measuring devices or measuring apparatuses for electric drives are often used to determine the relative movement or relative positioning (relatvage) of the respective machine part. In this case, the generated position value is supplied via a corresponding interface device to the servo electronics (Folgeelektronik) for actuating the drive.

Background

A sensor element for a revolution counter is described in EP 1740909B 1, in which domain walls occur, wherein the sensor element has a special spiral-shaped form.

Disclosure of Invention

The object on which the invention is based is to provide a sensor element or a storage system which comprises domain wall conductors and which enables robust operating characteristics with respect to external influences and can be produced relatively economically.

According to the invention, this object is achieved by the features of claim 1.

Sensor elements for the active storage of, in particular, rotational or positional information, comprise a domain wall conductor and a substrate, wherein the propagation of the domain wall conductor on the substrate is designed to be closed-loop, non-crossing and continuous. In addition, the domain wall conductor includes at least one first region having a positive curvature and at least one second region having a negative curvature.

The term active speaker (active speaker) is to be understood as meaning that the sensor element concerned does not require auxiliary energy storage.

In connection with the invention, the domain wall conductors are, in particular, conductor tracks (Leiterspuren) or conductor tracks or nanowires consisting of magnetizable material. Information may be stored in domain wall conductors in the form of oppositely magnetized domains. The domains are separated by so-called domain walls, which can be displaced by a magnetic field, wherein the position of the domains changes. To determine its position, a read-out element is arranged, through which domains or domain walls are moved. The domain wall conductor can therefore also be considered functionally as a type of shift register.

The propagation of the domain wall conductor constitutes a continuous curve and has neither abrupt nor sharp peaks, bends or any other points of disruption. The term "continuous course" is therefore to be understood as meaning the course of the domain wall conductor, which is formed uniformly without abrupt changes in direction. Mathematically, therefore, the course of the domain wall conductor is continuous over its entire length and is in particular differentiable, so that a unique tangent can therefore be generated at each point of the course of the domain wall conductor.

The non-crossing course of the domain wall conductor is to be understood in particular to mean that the domain wall conductor does not cross in its course, but is also not guided crossing one over the other in different layers (Lagen).

Curvature is to be understood as a change in direction along the course of the domain wall conductor on a, in particular, flat substrate. In the case of a straight course, the curvature is equal to zero, since the course direction does not change. The curvature with the symbol (Vorzeichen) can be defined for the orientation of the normal beam (Normalenb und) of the course of the domain wall conductor with respect to the course curve, as long as the curvature is not equal to zero. The curvature is positive if it is curved in the direction of the unit normal vector field, and negative if it is curved in the opposite direction. For example, a first region having a positive curvature may be referred to as a convex region, and then a second region having a negative curvature may be referred to as a concave region. Mathematically, the domain wall conductor therefore has in particular at least one point of inflection.

The sensor element advantageously comprises a particularly flat substrate, and the domain wall conductors are formed as conductor tracks on the substrate.

In a further embodiment of the invention, the domain wall conductor has a width of less than 1000 nm, in particular less than 500 nm, advantageously less than 300 nm.

The thickness or layer thickness of the domain wall conductor is advantageously less than 200 nm, in particular less than 150 nm, in particular less than 60 nm.

The substrate advantageously has a glass layer and/or a silicon layer. The sensor element can be built as part of a CMOS chip, especially when the substrate has a silicon layer.

According to an advantageous variant, the sensor element furthermore has a readout element by means of which the local magnetization state of the domain wall conductor can be determined (at the respective position of the readout element). Thus, the magnetization states of the domain wall conductors can be determined separately by the readout elements. The readout element is fixedly arranged with respect to the domain wall conductor.

In a further embodiment of the invention, the domain wall conductor is arranged in a layer between at least one of the readout elements and the substrate. Alternatively or additionally, at least one of the readout elements is arranged in a layer between the substrate and the domain wall conductor.

The read-out element is advantageously constructed as a GMR or TMR sensor.

The sensor element may have a plurality of domain wall conductors. In this case, the plurality of domain wall conductors have a different number of first regions or a different number of second regions. Thus, for example, a sensor element can have a first wall conductor and a second wall conductor, where the first wall conductor has a first number of first regions and the second wall conductor has a second number of first regions.

The different numbers, i.e. the number of first regions of the first wall conductor and the number of first regions of the second wall conductor, are advantageously coprime. As is known, the term "coprime" is to be understood as meaning that for the number concerned (natural number), there is no natural number other than 1 divided into two numbers (teilen).

According to another aspect, the invention also includes a storage system having a sensor element and having a read-out element and a magnetic device. The magnetic device is movable in a first direction relative to the domain wall conductor. Thereby causing displacement of the magnetic domains or domain walls.

The magnetic field generated by the magnetic means is advantageously configured asymmetrically with respect to an axis running parallel to the first direction. This consideration applies to any conceivable axis running parallel to the first direction.

In a further embodiment of the invention, the magnetic field generated by the magnetic device is advantageously embodied symmetrically with respect to an axis running parallel to the second direction. The second direction is oriented orthogonally to the first direction.

The axis running parallel to the first direction and the axis running parallel to the second direction lie in particular in a plane oriented parallel to the substrate.

In a further embodiment of the storage system, the magnetic device is designed as a magnet array having magnets, the poles of which are arranged offset to one another in the first direction.

Advantageously, two magnets offset from each other in the first direction have a polar orientation rotated by 180 °. The magnets concerned are therefore arranged such that the line of connection between the north and south poles of one magnet is parallel to the line of connection between the north and south poles of the other magnet, with the poles of the magnets being oriented oppositely. Thus, the staggered magnets may be referred to as being arranged anti-parallel to each other in view of the pole orientation.

In a further embodiment of the storage system, the magnet array has magnets, the poles of which are arranged offset to one another in a second direction, the second direction being oriented orthogonally to the first direction.

Advantageously, two magnets offset from each other in the second direction and adjacent to each other in particular have a pole orientation rotated by 180 °.

The course of the domain wall conductor is advantageously formed to be axially symmetrical. In particular, the axis of symmetry concerned can run parallel to the second direction or in the second direction.

The domain wall conductor has an expansion in a first direction and the two poles have a center-to-center distance, wherein the expansion is smaller than the center-to-center distance. The maximum expansion of the domain wall conductor in the first direction is to be understood here in particular. The center-to-center distance may in particular be the distance between the effective centers of the magnets. For example, in the case of a cylindrical bar magnet, the center-to-center distance can be considered as the distance between the longitudinal axes of the cylindrical bar magnets.

The memory system is designed such that it has at least two domain walls, wherein configurations with four or more domain walls can also be used.

Advantageous embodiments of the invention emerge from the dependent claims.

Further details and advantages of the sensor according to the invention emerge from the following description of an embodiment according to the accompanying drawings.

Drawings

Figure 1 shows a top view of a sensor element,

figure 2 shows a detailed view of a domain wall conductor,

figure 3 shows the magnets of the magnetic device,

figure 4 shows a top view of the magnetic means on the carrier plate,

figure 5 shows a top view of a magnetic device with a schematic of the magnetic field,

figure 6 shows a side view of a scale element according to a first embodiment,

figure 7 shows a top view of a scale element and a sensor element according to a first embodiment,

figure 8 shows a schematic view of the sensor element and the magnetic means in a first relative position to each other,

FIG. 9 shows a partial view of a domain wall conductor with a domain wall drawn in a first relative position;

figure 10 shows a schematic view of the sensor element and the magnetic means in a second relative position to each other,

figure 11 shows a partial view of a domain wall conductor with a drawn domain wall in a second relative position,

figure 12 shows a schematic view of the sensor element and the magnetic means in a third relative position to each other,

figure 13 shows a partial view of a domain wall conductor with a drawn domain wall in a third relative position,

figure 14 shows a schematic view of the sensor element and the magnetic means in a fourth relative position to each other,

figure 15 shows a partial view of a domain wall conductor with a drawn domain wall in a fourth relative position,

figure 16 shows a schematic view of the sensor element and the magnetic means in a fifth relative position to each other,

figure 17 shows a partial view of a domain wall conductor with a drawn domain wall in a fifth relative position,

figure 18 shows a schematic view of the sensor element and the magnetic means in a sixth relative position to each other,

figure 19 shows a partial view of a domain wall conductor with a drawn domain wall in a sixth relative position,

figure 20 shows a view of a domain wall conductor with domain walls drawn in at another relative position during a second revolution,

figure 21 shows a view of a domain wall conductor with a wall drawn in another relative position after the second revolution is completed,

figure 22 shows a view of a domain wall conductor with a wall drawn in another relative position after the third revolution is completed,

figure 23 shows a view of a domain wall conductor with a wall drawn in another relative position after the fourth revolution is completed,

figure 24 shows a view of a sensor element with another domain wall conductor,

figure 25 shows a top view of a scale element according to a second embodiment,

figure 26 shows a top view of a scale element according to a third embodiment,

figure 27 shows a top view of a sensor element according to a fourth embodiment,

figure 28 shows a top view of a magnetic device according to a fourth embodiment,

fig. 29 shows a side view of a magnetic device with a sensor element according to a fourth embodiment.

Detailed Description

Fig. 1 shows a sensor element comprising a domain wall conductor 1 and a substrate 2, wherein the domain wall conductor 1 is applied to the substrate 2 in the form of a conductor track. In the exemplary embodiment presented, the substrate 2 has a mechanically supporting glass layer, the substrate 2 being formed flat. Alternatively, the substrate 2 can have a silicon layer, wherein the sensor element can then be formed as part of a CMOS chip.

The domain wall conductor 1 comprises a soft magnetic material, such as a Ni-Fe alloy. The domain wall conductor 1 comprises a first segment 1.1 in which the domain wall conductor 1 extends in a relatively narrow loop and a second segment 1.2 in which the domain wall conductor 1 extends in an arc having a relatively large radius 1.1. The first section 1.1 and the second section 1.2 directly adjoin one another, so that the wall conductor 1 is designed to be closed-loop.

The domain wall conductor 1 has a width X1 in the first direction X and is constructed symmetrically with respect to an axis C which is oriented perpendicularly to the first direction X and parallel to the second direction y. In the proposed embodiment, the width X1 is 70 μm, with the domain wall conductor 1 extending in the second direction y over 5 mm.

Fig. 2 shows a segment of a domain wall conductor 1. It is clearly seen therein that the domain wall conductor 1 comprises in its course a first region a with a positive curvature and a second region B with a negative curvature. In other words: if one were to follow the course of the domain wall conductor 1, one would encounter not only segments with right curvature (Rechtskkrummung) but also segments with left curvature (Linkskrummung). In the course of the first segment 1.1, the first region a with positive curvature is followed by the second region B with negative curvature and then again by the first region a, and so on, wherein in the proposed embodiment the region with the linear course of the domain wall conductor 1 is located between the first region a and the second region B. In the second segment 1.2, the sign of the curvature is not transformed. In the exemplary embodiment presented, the curvature or the radius of curvature is designed to be constant there.

According to fig. 1, a readout element 7, which may be, for example, a GMR sensor or a TMR sensor, is located in a layer above the domain wall conductor 1, by means of which the magnetization state of the domain wall conductor 1 located below can be determined. Alternatively, the readout element 7 can also be arranged between the domain wall conductor 1 and the substrate 2.

The domain walls W1, W2 are displaced within the domain wall conductor 1 or along the domain wall conductor 1 if a magnetic field moving relative to the domain wall conductor 1 acts appropriately on the domain wall conductor 1. In order to form a suitable magnetic field, a magnetic device 3 is used, which in the embodiment presented is designed as a magnet array, which consists of a plurality of magnets 3.1 to 3.6. The magnet 3.1 is shown in fig. 3 for all magnets 3.1 to 3.6 by way of example. In the exemplary embodiment presented, all the magnets 3.1 to 3.6 are of identical design. The magnets 3.1 to 3.6 are thus designed as cylinders, the magnetic poles being arranged along the longitudinal (l ä ngsten) axis of symmetry in the sense of bar magnets.

The corresponding magnetic means 3 are shown in fig. 4. The magnetic device 3 is shown on a different scale than the domain wall conductor 1 in figure 1. The magnets 3.1 to 3.6 are arranged on the carrier 4 according to a predetermined pattern in different north-south orientations (Nord-Sud-Orientiertering). The magnets 3.1 to 3.6 may also be embedded in the carrier 4.

In particular, the magnets 3.1 to 3.3 may be arranged in a row along the first direction X with a distance X2, wherein adjacent magnets 3.1 and 3.2 or 3.2 and 3.3 have opposite polar orientations. The other magnets 3.4 to 3.6 are arranged offset in the second direction y in rows along the first direction X, likewise at a distance X2. In the proposed embodiment, the distance X2 is 0.33 mm. The magnet 3.6 is offset in the second direction y relative to the remaining magnets 3.1 to 3.5.

An auxiliary magnetic field (Stutz magnetfeld) is arranged in the x-direction on both sides alongside the magnetic means 3. The magnetic field can therefore be illustrated in a simplified manner according to fig. 5, wherein the arrows with large stripe widths on the left and right next to the magnets 3.1 to 3.6 should indicate the auxiliary magnetic field. In fig. 5, it can be seen that the direction of the magnetic field lines changes, so that rotating or rotating magnetic field lines are formed, wherein there is a rotation of the magnetic field lines about axes oriented in a third direction z (see fig. 3), respectively.

The magnetic field generated by the magnetic means 3 is formed asymmetrically with respect to an axis Ax extending parallel to the first direction x. In particular, there is no axis extending parallel to the first direction x, which may represent an axis of symmetry. Conversely, the magnetic field generated by the magnetic device 3 is formed symmetrically with respect to an axis Ay running parallel to the second direction y, so that an axially symmetrical magnetic field is present with respect to the axis Ay.

As an alternative to the embodiment shown here, the bar magnets can also lie in a plane oriented parallel to the first direction x and parallel to the second direction y, so that the north pole and the south pole shown in fig. 5 belong at least partially to the same magnet, in particular to a magnet lying in the xy plane.

The magnetic device 3 is usually fixed on a scale element 6 or on a measuring scale (Ma β verk) or on a baby ribbon. According to the first embodiment according to fig. 6 and 7, the scale element 6 has as a main body a substantially annular pillar (Trommel) 6.1. At its outer circumference, a magnetic device 3 consisting of magnets 3.1 to 3.6 and a carrier 4 is mounted. Furthermore, the column 6.1 has an auxiliary magnet 6.11 in the region of the outer circumference. The auxiliary magnet may for example consist of a layer made of magnetizable material. The magnetization is carried out such that the north pole and the south pole are arranged axially offset to one another. In the proposed exemplary embodiment, the fine scale 6.12 is applied circumferentially on the column 6.1 in the second direction y, i.e. offset in the axial direction with respect to the auxiliary magnet. The fine scale can be decoded, for example, by an optical scanning device, which is likewise accommodated in the housing 5. Alternatively, the magnetic means 3 may also be arranged in the inner circumference of the column or hollow shaft.

The sensor element, i.e. the domain wall conductor 1, together with the substrate 2, is located opposite a radial gap within the housing 5. In the proposed embodiment, the housing is fixed and the column 6.1 is rotatably mounted together with the magnetic means 3 such that the magnetic means 3 moves when the column 6.1 is rotated in the first direction x (or vice versa) relative to the magnetic means 3.

In fig. 8, the magnetic device 3 and the domain wall conductor 1 are shown in a first attitude (Stellung) to each other as a schematic diagram. In this pose, the domain walls W1, W2 are in positions according to fig. 9, where (as indicated by the symbols) the first wall W1 is a so-called head-to-head domain wall and the second wall W2 is a so-called tail-to-tail domain wall. If the domain wall conductor 1 is now moved together with the substrate 2 in the first direction x according to the arrow in fig. 8 relative to the magnetic device 3, the domain wall conductor 1 is guided through the rotating magnetic field to some extent (quasi) (as shown in fig. 5). Thus, the positions of the domain walls W1, W2 are shifted.

In fig. 10, the domain wall conductor 1 is shown in another attitude, where the magnetic field is rotated relative to the first attitude. Accordingly, the domain walls W1, W2 have changed their position (fig. 11).

Similarly, due to further displacement of the domain wall conductor 1 along the first direction x (fig. 12, 14, 16, 18), the positions of the domain walls W1, W2 are further displaced (fig. 13, 15, 17, 19). The positions of the domain walls W1, W2 according to fig. 19 contain, for example, information: the column 6.1 has ended the first revolution.

When further moved or rotated in the same direction, the domain wall conductor 1 remains under the influence of the auxiliary magnetic field, so that the positions of the domain walls W1, W2 then no longer change.

In the proposed embodiment, the pillar 6.1 should be rotated further in the same direction x, so that the domain wall conductor 1 comes again into the magnetically influenced region of the magnetic means 3 at the end of the second revolution. The position of the domain wall W1, W2 during the second revolution is shown in fig. 20, with the domain wall conductor 1 together with the substrate 2 in the attitude according to fig. 14 (the pillars 6.1 are then rotated further 360 °). In particular, the displacement of the domain walls W1, W2 over the length of the second segment 1.2 is achieved by the magnetic or auxiliary field of the magnets 3.6 arranged offset in the second direction y, in which second segment 1.2 the domain wall conductor 1 extends in an arc with a relatively large radius. At the end of the second revolution, if the domain wall conductor 1 is in the attitude according to fig. 18 (with respect to the situation in fig. 18, the pillar 6.1 has rotated further 360 °), the domain walls W1, W2 assume the positions according to fig. 21.

The position of the wall W1, W2 after the third revolution of the pillar 6.1 is shown in fig. 22. In this state, the domain wall conductor 1 is in the attitude according to fig. 18 (the pillar 6.1 is then rotated further 720 °).

Thus, the positions of the wall W1, W2 according to figure 23 show that the pillar 6.1 has completed the fourth revolution (however, as in the case of figure 18, the attitude of the pillar 6.1 has rotated further 1080 °). The positions of the domain walls W1, W2 correspond to the positions of the initial states.

After each pass of the magnetic means 3 or after each revolution of the column 6.1, the domain wall W1 has thus moved further into the adjacent first region a of the domain wall conductor 1. Accordingly, after each revolution the domain wall W2 has moved further to the adjacent second region B of the domain wall conductor 1 or the domain wall is located in a second segment 1.2 in which the domain wall conductor 1 extends in an arc with a relatively large radius, respectively.

The magnetization direction within the segment of the domain wall conductor 1 and thus the coarse position of the domain walls W1, W2 can be detected by the read-out element 7. In this way, it is possible to count the revolutions or store the revolution information even if assistance cannot be available. This is important when the shaft is moved in the case of a power failure (stromiaufall), for example due to a gravity load (gewichtbalting). Furthermore, the domain walls W1, W2 are displaced in relation to the direction of rotation, so that the sensor element can be used reliably in applications which allow two directions of rotation.

To increase the number of countable revolutions, a plurality of domain wall conductors 1 can be provided, as is shown in a simplified manner in fig. 24. In this case, it is advantageous if the plurality of domain wall conductors 1 have a different number of first segments 1.1, in particular a different number of first regions a or a different number of second regions B. When a plurality of domain wall conductors 1 are used, it is advantageous if the number of first regions a is, in particular, coprime (teilerfront). The domain wall conductors 1 may be arranged offset from one another or staggered from one another in the first direction x (inelnder versachtel). In fig. 24, the domain wall conductor is constructed such that it has four and five first regions a, wherein for the sake of clarity, a domain wall conductor with a smaller number of first regions is shown in fig. 24. In practice, it is suitable to use domain wall conductors having more than just four first regions. For example, four domain wall conductors with 7, 9, 11, 13 first regions may be used, so that 9009 (7 x 9 x11 x 13) revolutions would then be countable.

For the function of the storage system, it is important that a magnetic field, the direction of which varies as a function of the x position, acts on the domain wall conductor 1 when running through the magnetic device 3 in the first direction x. In particular, there are rotating or rotating magnetic lines or field directions during the passage of the vehicle. When passing (no change in direction), the magnetic lines of force on one side of the axis Ax (fig. 5) have an opposite rotational direction than the magnetic lines of force on the other side of the one axis Ax.

A second embodiment is shown in fig. 25. Here, the magnetic means 3 are fastened at the end face of the column 6.2. The sensor elements not shown in the drawing are arranged axially offset, i.e. with a gap having an axial extent (ausdehnnung). The pivot information is updated each time the magnetic device 3 drives past (vorbeifahrt) the sensor element, wherein the domain walls W1, W2 are displaced in relation to the direction of rotation.

A third embodiment is described with reference to fig. 26. In the case of this embodiment, the sensor element is used in conjunction with a linear scale 6.3. In the proposed embodiment, the scale 6.3 comprises a first scale portion 6.31 and a second scale portion 6.32. The first scale portion 6.31 and the second scale portion 6.32 are arranged in a row along the first direction x, such that a comparatively large measuring length can be achieved. In practice, more than just two scale portions may absolutely also be arranged in a row. The first scale part 6.31 comprises an auxiliary magnet 6.311 and the second scale part 6.32 comprises an auxiliary magnet 6.321. The magnetic means 3 are laterally arranged in the first direction x offset with respect to the auxiliary magnets 6.311, 6.321. The scanning head, which is not shown in fig. 26, has a sensor element with a domain wall conductor 1 and a scanning device with incremental tracks (inkremenalspur) 6.313, 6.323 and absolute tracks 6.312, 6.322 (the incremental tracks 6.313, 6.323 and the absolute tracks 6.312, 6.322 extend over two scale segments 6.31, 6.32). By means of the sensor elements it is possible to store position information such that it can be determined exactly which of the scale portions 6.31, 6.32 is scanned.

A fourth embodiment may be explained with reference to fig. 27 to 29. In fig. 27, a sensor element is shown, which has a domain wall conductor 1 'modified in relation to the preceding embodiments, the domain wall conductor 1' extending around a central rotation point (illustration of the readout element is omitted in this figure). For the displacement of the domain wall, a magnetic device 3 'is used as an example, which magnetic device 3' comprises two disk-shaped magnets 3.1', 3.2', in particular with different diameters, according to fig. 28. The magnets 3.1', 3.2' have diametrically opposite magnetizations, so that the poles are arranged radially offset from one another. The magnets 3.1', 3.2' are arranged offset to one another along the axis G (i.e. axially), with their polar orientation being twisted by 180 ° about the axis G. The magnets 3.1', 3.2' are themselves inserted into the respective storage system in a fixed manner relative to one another and therefore cannot be twisted or displaced relative to one another in any manner. As shown in fig. 29, the distance g1 between the domain wall conductor 1 'or substrate 2 and the magnet 3.1' with the larger diameter is greater than the distance g2 between the domain wall conductor 1 'or substrate 2 and the magnet 3.2' with the smaller diameter (g 1> g 2). In this way, a magnetic field can be generated by which a suitable displacement of the domain wall is achieved when the domain wall conductor 1 'or the substrate 2 is rotated about the axis G relative to the magnetic device 3' or moved along the first direction x 'relative to the magnetic device 3'. Thereby, the number of revolutions of the substrate 2 relative to the magnetic means 3' can be counted.