Scanning element and inductive position measuring device equipped with this scanning element

Abstract

To provide a scanning element and an inductive position measuring device having the scanning element.SOLUTION: A scanning element includes a multi-layer printed-circuit board and an electronic component, and the printed-circuit board includes a first detector unit having a first receiver track. Moreover, the printed-circuit board includes a second detector unit having a second receiver track. The printed-circuit board has a geometrical center plane located between the detector units. Each receiver track includes first and second reception conductor traces, each having a periodic route. The first receiver track includes a first gap defined by the first reception conductor path along the extension. The second receiver track includes a second gap defined by the second reception conductor path. The printed-circuit board further includes a through-hole. This through-hole is also arranged in the first and second gaps.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The invention relates to a scanning element for an inductive position measuring device according to claim 1 for determining the position of the scanning element relative to two scale elements which can rotate at different speeds, and to a position measuring device equipped with such a scanning element.

[0002] Inductive position measuring devices are used, for example, as angle measuring instruments for determining the angular position of machine parts that can rotate relative to one another. In inductive position measuring devices, excitation and receiving lines are often mounted, for example in the form of conductor tracks, on a common, usually multilayer, printed circuit board, which is fixedly connected, for example, to the stator of the angle measuring device. Opposite this printed circuit board is a scale element that has a pitch structure and is non-rotatably connected to the rotor of the angle measuring device. When a time-varying excitation current is applied to the excitation lines, a signal dependent on the angular position is generated in the receiving coil while the rotor and stator are rotating relative to one another. These signals are then further processed by evaluation electronics.

[0003] In particular, in robot drives, inductive position measuring devices are frequently used as measuring instruments for determining the angular position of a drive shaft and simultaneously accurately determining the angular position of a driven shaft, where the movement of the drive shaft is introduced into the driven shaft by a reducer. In this case, the angular position is measured using a scanning element including a printed circuit board with corresponding detector units on both sides, so that the angular positions of the respective scale elements rotatably arranged on both sides of the printed circuit board can be determined. [Background technology]

[0004] JP 2006208239 discloses a position measuring device with two rotors with a stator arranged between them, in particular according to Figure 6 of this document. The position measuring device described there is used, for example, with a micrometer screw. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2006208239 Summary of the Invention [Problem to be solved by the invention]

[0006] The invention is based on the problem of creating a scanning element for an inductive position measuring device which allows the determination of the position or angular position of two scale elements, operates relatively accurately, is compact and can be manufactured cheaply. [Means for solving the problem]

[0007] This problem is solved according to the invention by the features of claim 1. A scanning element suitable for and designed for an inductive position measuring device includes a multilayer printed circuit board with a first detector unit and a second detector unit, and electronic components. The first detector unit has a first excitation line and a first receiving line and is arranged on a first and second layer of the printed circuit board. The second detector unit has a second excitation line and a second receiving line and is arranged on a third and fourth layer of the printed circuit board. The printed circuit board has a geometric center plane located between the detector units, and the first receiving line and the second receiving line are arranged circumferentially around the axis. The first receiving line includes a first receiving conductor, and the second receiving line includes a second receiving conductor. Each of these receiving conductors has a periodic path. The first receiving line has a first gap along its circumferential extension, the first gap being defined in the circumferential direction by the first receiving conductor. The second receiving wire has a second gap along its extension in the circumferential direction, the second gap being defined in the circumferential direction by the second receiving conductor. The printed circuit board has a through hole that is arranged in both the first gap and the second gap. Thus, in particular, the through hole is arranged in the circumferential direction between the first receiving conductor and the second receiving conductor.

[0008] In defining the spatial arrangement of the subject matter of the invention, a first direction x can first be defined. The first direction x represents the direction (measuring direction) along which the determined position is measured. The first direction x is a circumferential or tangential direction since the position measuring device is to measure a first relative angular position of the first scale element and scanning element simultaneously with a second relative angular position of the second scale element and scanning element for a rotational or pivoting movement about an axis, respectively.

[0009] Additionally, a second direction y can be defined that is orthogonal to the first direction x. A third direction z is oriented perpendicular to the first direction x and perpendicular to the second direction y. The third direction z is parallel to an axis about which the scale element can rotate relative to the scanning element. Furthermore, the third direction z is perpendicular to the central plane. The layers of the printed circuit board are offset relative to one another in the third direction z.

[0010] In particular, one end of the through hole, i.e., one contact portion, can be located in the first gap and the other end, i.e., the other contact portion, can be located in the second gap. The through hole can in particular extend in a third direction z.

[0011] Typically, both largest faces of a printed circuit board are oriented parallel to one another, and the central plane is in particular arranged parallel to and centered between these faces, so that the distance between one face of the printed circuit board and the central plane is exactly the same as the distance between the other face of the printed circuit board and the central plane, in particular in the third direction z.

[0012] In a further aspect of the invention, the first excitation line and the second excitation line extend along the circumferential direction or the first direction x. Advantageously, both the first and second receiving lines and the first and second excitation lines extend in the circumferential direction or along the first direction x.

[0013] Advantageously, the scanning element is configured such that the first excitation line and the second excitation line are electrically connected in series. Advantageously, the first and second excitation lines can be energized with an excitation current (alternating current or mixed current), which usually has a current intensity that varies over time. The excitation current can be generated by electronic components, i.e., its path can be formed by electronic components. Since there is a physical relationship between current intensity and voltage intensity, the same can naturally be considered for the excitation voltage.

[0014] In a further embodiment of the invention, the signals that can be generated by the first and second receiving lines can be further processed, in particular by electronic components that form an evaluation circuit. That is, the electronic components may be elements of different electronic circuits or may be assigned to different circuits, for example, one electronic component may be a circuit element for generating an excitation current and a further electronic component may be a further circuit element for evaluating or further processing the signal.

[0015] Advantageously, the printed circuit board is configured such that the through holes electrically connect the first detector unit with the third or fourth layer. Alternatively, the through holes can electrically connect the second detector unit with the first or second layer. In particular, the through holes can connect conductor tracks that are present on the first, second, third, or fourth layer, respectively.

[0016] In a further embodiment of the invention, the through hole is in electrical contact with one of the electronic components, so that a signal generated by the first detector unit or the second detector unit, i.e. by its receiving conductor path, can be supplied to the electronic component via the through hole.

[0017] In an advantageous embodiment of the present invention, a through-hole is used as a through-hole via. A through-hole is in particular created by a continuous hole that passes through a printed circuit board. The hole is preferably provided with a metal layer, in particular a copper layer, on its inner wall. Contacts above and below the through-hole form an electrical contact with the printed circuit board, a conductor layer, or an electronic component. In the following, the term through-hole can also be interpreted as an arrangement in which multiple holes or hollow spaces filled or coated with a conductive material are offset from one another (in particular radially or circumferentially). Such through-holes are often also called staggered (or staggered) vias.

[0018] In a further aspect of the invention, the first gap extends a first length in the circumferential direction, and the first receiving conductor has a periodic path with a first periodic length λ1, where the first length is equal to or greater than 1 / 8 of the first periodic length λ1, i.e., L1(first periodic length)≧1 / 8·λ1.

[0019] Advantageously, the scanning element is configured such that the second gap extends a second length in the circumferential direction and the second receiving conductor has a periodic path with a second period length λ2, where the second length is greater than or equal to 1 / 8 of the second period length λ2, i.e., L2 (second period length) ≥ 1 / 8 λ2.

[0020] In a further embodiment of the invention, the first receiving conductor has a periodic path with a first period length λ1, and the second receiving conductor has a periodic path with a second period length λ2, the second period length λ2 being equal to or greater than the first period length λ1 (λ2≧λ1).

[0021] In an advantageous embodiment of the invention, the second detector unit and at least one of the electronic components are arranged on the same side of the printed circuit board, i.e., in this construction, the second detector unit and the electronic component are offset in the same direction relative to the central plane, so that the central plane is not located between the second detector unit and the electronic component.

[0022] Advantageously, the first detector unit has a third receiving line, and the second detector unit has a fourth receiving line. In particular, the third receiving line can include a third receiving conductor having a periodic path, the periodic length of which is smaller than the first periodic length λ1 of the first receiving conductor. Furthermore, the fourth receiving line can include a fourth receiving conductor having a periodic path, the periodic length of which is larger than the second periodic length λ2 of the second receiving conductor.

[0023] In a further aspect of the invention, the first detector unit has a third excitation line and the second detector unit has a fourth excitation line. In an advantageous embodiment, the first shield layer is disposed on the fifth layer of the printed circuit board, the second shield layer is disposed on the sixth layer of the printed circuit board, and the through holes penetrate the first and second shield layers without electrically contacting the shield layers. The central plane is located between the first and second shield layers, so that the shield layers are disposed on both sides of the central plane.

[0024] The central plane is located between the first detector unit and the first shield layer in the third direction z. Accordingly, it is equally true that the central plane is located between the second detector unit and the second shield layer in the third direction z, and that the second detector unit and the second shield layer are disposed on either side of the central plane.

[0025] According to a further aspect, the invention also includes an inductive position measuring device comprising a scanning element and first and second scale elements spaced apart on opposite sides of the printed circuit board in a third direction z (a direction perpendicular to the central plane).

[0026] Advantageously, the first scale element has a first diameter D1 and the second scale element has a second diameter d2, the first diameter D1 being greater than the second diameter d2 (D1>d2). Additionally, the scale element may be arranged to be rotatable about a common axis relative to the scanning element.

[0027] Furthermore, at least one of the electronic components can be positioned further away from the axis than the outer contour of the second scale element, i.e., the at least one electronic component is positioned radially outward from the second scale element.

[0028] Advantageous configurations of the invention emerge from the dependent claims. Further details and advantages of the scanning element according to the invention will become apparent from the following description of one embodiment with reference to the accompanying drawings. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a perspective view of a position measuring device including a scanning element, a first scale element, and a second scale element. [Figure 2] FIG. 2 is a plan view of a first side of a scanning element. [Figure 3] FIG. 2 is a detailed plan view of a first side of the scanning element. [Figure 4] FIG. 4 is a plan view of a second side of the scanning element. [Figure 5] FIG. 4 is a detailed plan view of a second side of the scanning element. [Figure 6] Detailed cross-sectional view of the scanning element at PP. [Figure 7] Detail cross section of the scanning element in the region of the through-hole. [Figure 8] FIG. 2 is a plan view of a first scale element. [Figure 9] FIG. 10 is a plan view of a second scale element. DETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention will be described with reference to FIG. 1 with reference to a position measuring device having a scanning element 1 that can be used to determine both the angular position of a first scale element 2 and the angular position of a second scale element 3. The two scale elements 2, 3 are arranged rotatably about axis R relative to the scanning element 1. Such a position measuring device can be used, for example, in a robot drive. The second scale element 3 is then non-rotatably connected, for example, to a drive shaft of a motor, which in turn is connected to a reducer with a driven shaft. The first scale element 2 rotates together with this driven shaft. In this way, for example, the angular position for motor commutation can be determined using the second scale element 3, and the angular position for robot positioning with relatively high precision can be determined using the first scale element 2.

[0031] The scanning element 1 includes a printed circuit board 1.1 having several layers and electronic components 1.2 mounted on the printed circuit board 1.1. The scanning element 1 is used to scan a first scale element 2 and a second scale element 3 simultaneously. In this embodiment, the electronic components 1.2 are mounted only on the second surface. However, it is also possible, alternatively or additionally, to mount the electronic components on the first surface of the printed circuit board 1.1.

[0032] To determine the angle information, a first detector unit 1.11 is arranged on a first side of the printed circuit board 1.1 and a second detector unit 1.12 is arranged on a second side of the printed circuit board 1.1. Only the structure of the second detector unit 1.12 that is on the outer fourth layer F (see Figures 6 and 7) is visible in Figure 1.

[0033] 2 and 3 (FIG. 3 is an enlarged detailed view of the first detector unit 1.11 according to FIG. 2) show, inter alia, the structure of the first detector unit 1.11 on the first outer layer A of the printed circuit board 1.1 and on the second layer B of the printed circuit board 1.1. The first detector unit 1.11 includes a first excitation line 1.111, a first receiving line 1.112, a third excitation line 1.113, a third receiving line 1.114, and a fifth excitation line 1.115. The first receiving line 1.112 includes a first receiving conductor path 1.1121.

[0034] In Figures 4 and 5, the other side of the printed circuit board 1.1 is shown, thereby revealing the second detector unit 1.12. Figure 5 shows an enlarged view of the second detector unit 1.12 in detail. Figures 4 and 5 show, inter alia, the structure of the second detector unit 1.12 on the outer fourth layer F of the printed circuit board 1.1 and on the third layer E of the printed circuit board 1.1. The second detector unit 1.12 includes a second excitation line 1.121, a second receiving line 1.122, a fourth excitation line 1.123, a fourth receiving line 1.124, and a sixth excitation line 1.125. The second receiving line 1.122 includes a second receiving conductor 1.1221.

[0035] FIG. 6 shows a schematic partial cross-section of the scanning element 1 or printed circuit board 1.1 along the section line PP. For clarity, the hatching of the electrically insulating material of the printed circuit board 1.1 has been omitted. Furthermore, the partial cross-section of FIG. 6 is not drawn to scale in order to better illustrate the scanning element 1 according to the present invention. As already mentioned above, the printed circuit board 1.1 has a multi-layer structure. Geometrically, a so-called central plane M can be defined for the printed circuit board 1.1, which is disposed parallel to the first side of the printed circuit board 1.1 and parallel to the second side, respectively, at the center between the first and second side surfaces. Furthermore, the geometric relationship of the individual elements to one another can be defined using a coordinate system, where the first direction x is the direction in which the position or angle measurement is intended to be performed. In this embodiment, the first direction x corresponds to the circumferential direction. The axis R about which the scale elements 2, 3 can rotate extends parallel to the third direction z, which may also be defined here as the axial direction. A second direction y is oriented perpendicular to the third direction z and the first direction x, and can also be called the radial direction. Thus, the plane formed by the x- and y-axes is oriented parallel to the central plane M, and the third direction z and the axis R extend perpendicular to the central plane M.

[0036] A first detector unit 1.11 is arranged on the first layer A of the printed circuit board 1.1 and on the second layer B of the printed circuit board 1.1, while a second detector unit 1.12 is arranged on the third layer E and the fourth layer F. The first layer A is closest to the first side of the printed circuit board 1.1, and the second layer B is second closest to the first side of the printed circuit board 1.1. The same is true for the fourth layer F and the third layer E on the second side of the printed circuit board 1.1.

[0037] The excitation lines 1.111, 1.113, 1.115 of the first detector unit 1.11 include excitation conductor paths 1.1111, 1.1131, 1.1151 that extend to the first layer A. Similarly, the excitation lines 1.121, 1.123, 1.125 of the second detector unit 1.12 include excitation conductor paths 1.1211, 1.1231, 1.1251 that extend to the fourth layer F.

[0038] Furthermore, the printed circuit board 1.1 also includes a fifth layer D and a sixth layer C. The fifth layer D includes a first shield layer 1.13, and the sixth layer C includes a second shield layer 1.14. Here, the shield layers 1.13 and 1.14 are copper layers with relatively large areas.

[0039] The excitation wires 1.111, 1.113, 1.115 of the first detector unit 1.11 surround the first receiving wire 1.112 or the third receiving wire 1.114. The excitation wires 1.121, 1.123, 1.125 of the second detector unit 1.12 surround the second receiving wire 1.122 or the fourth receiving wire 1.124. Both the excitation wires 1.111, 1.113, 1.115, 1.121, 1.123, 1.125 and the receiving wires 1.112, 1.114, 1.122, 1.124 extend in the circumferential or first direction x.

[0040] In this embodiment, the receiving lines 1.112, 1.114, 1.122, and 1.124 respectively include receiving conductors 1.1121, 1.1141, 1.1221, and 1.1241, which are circumferentially offset, thereby providing four signals with corresponding phase shifts. In the figure, the receiving conductors 1.1121, 1.1141, 1.1221, and 1.1241 belonging to the same receiving line 1.112, 1.114, 1.122, and 1.124 are each labeled with a single reference number. Thus, for example, all receiving conductors 1.1121 of the first receiving line 1.112 are each labeled with a single reference number. Furthermore, the first receiving conductor 1.1121 of the first detector unit 1.11 is connected to vias and runs on different layers of the printed circuit board 1.1, thereby avoiding undesired short circuits at crossing points. The same is true for the receiving conductors 1.1221, 1.1241 of the second detector unit 1.12. Strictly speaking, each of the first and second receiving conductors 1.1121, 1.1221 consists of a number of conductor pieces arranged side by side and distributed over two planes or layers, respectively, but in the following such structures will be referred to collectively as a single receiving conductor 1.1221, 1.1241.

[0041] The receiving conductors 1.1121, 1.1141, 1.1221, 1.1241 have a spatially periodic path that is approximately sinusoidal or sinusoidal. The receiving conductors 1.1121 of the first receiving line 1.112 have a periodic length λ1 (FIG. 3), while the receiving conductors 1.1221 of the second receiving line 1.122 have a periodic length λ2 (FIG. 5). In this example, adjacent receiving conductors 1.1121, 1.1141, 1.1221, 1.1241 within one receiving line 1.112, 1.114, 1.122, 1.124 are offset from each other by 1 / 8 of a complete sinusoidal period (π / 4 or 45° along the circumferential or first direction x). The receiving conductors 1.1121, 1.1141, 1.1221, 1.1241 are electrically connected to provide 0° and 90° signals on one side and 45° and 135° signals on the other side. A first position signal can be determined from the 0° and 90° signals, and a second position signal, redundant to the first position signal, can be determined from the 45° and 135° signals.

[0042] In this embodiment, the second period length λ2 is greater than the first period length λ1. As shown in FIGS. 2 and 3, the first receiving line 1.112 has a first gap U1 along its extension in the circumferential direction (x-direction). The region of the first gap U1 is defined by the first receiving conductors 1.1121, so that no detection structures are present between the defining receiving conductors 1.1121. In other words, to a first approximation, the first gap U1 is also a region that is, geometrically, a ring segment. In the region of the first gap U1, the minimum circumferential distance L1 between two first receiving conductors 1.1121 is 5 / 8 λ1 (U1 = 5 / 8 λ1) in this embodiment. In other words, no periodically extending first receiving conductors 1.1121 are arranged in the region of the first gap U1.

[0043] 4 and 5, the second receiving line 1.122 has a second gap U2 along its circumferential extension. This second gap U2 is defined by the second receiving conductors 1.1221. The minimum circumferential distance L2 between two second receiving conductors 1.1221 in the region of the second gap U2 is 13 / 8 (U2 = 13 / 8 λ2) in this example. That is, no periodically extending second receiving conductors 1.1221 are arranged in the second gap U2.

[0044] The printed circuit board 1.1 further includes through holes 1.15, 1.16. FIG. 7 shows a schematic partial cross-section of the scanning element 1 or printed circuit board 1.1 in the region of the through holes 1.15, 1.16. The through holes 1.15, 1.16 are implemented here as through-hole vias and thus penetrate the printed circuit board 1.1 over its entire thickness. The through holes 1.15, 1.16 thus extend parallel to the third direction z. Accordingly, the printed circuit board 1.1 is configured such that the through holes 1.15, 1.16 are located both in the first gap U1 and in the second gap U2.

[0045] The through hole 1.15 electrically connects the first receiving conductor 1.1121 of the first receiving line 1.112 to the electronic component 1.2 located beyond the central plane M. For this purpose, a conductor running on the second layer B electrically connects the first receiving conductor 1.1121, not visible in FIG. 7, to the through hole 1.15. The through hole 1.15 passes through the first shield layer 1.13 and the second shield layer 1.14, which are structured so that they are not electrically connected to the through hole 1.15. On the third layer E, the conductor runs into a conductor running on this layer E. This conductor is electrically connected to a further via, here a blind or microvia, which ultimately connects to the electronic component 1.2.

[0046] A further through hole 1.16 connects the first receiving conductor 1.1121, which runs on the first layer A, with the fourth layer F. Electrical contact is made to the electronic component 1.2 via conductors which are not visible in the drawing.

[0047] The first receiving line 1.112 is arranged to overlap the second receiving line 1.122 in the second direction y. Figure 8 shows a plan view of the first scale element 2. Figure 9 also shows a plan view of the second scale element 3. The scale elements 2 and 3 have a disk-like shape, with the first scale element 2 having a first diameter D1 and the second scale element 3 having a second diameter d2. The first diameter D1 is larger than the second diameter d2 (D1>d2).

[0048] In the illustrated embodiment, the scale elements 2 and 3 each comprise an epoxy resin substrate on which two pitch lines 2.1, 2.2; 3.1, 3.2 are disposed. The pitch lines 2.1, 2.2; 3.1, 3.2 are ring-shaped and arranged concentrically on the substrate with different diameters relative to the axis R. The pitch lines 2.1, 2.2; 3.1, 3.2 each comprise a pitch structure consisting of a periodic sequence of alternating conductive pitch regions 2.11, 2.21; 3.11, 3.21; and non-conductive pitch regions 2.12, 2.22; 3.12, 3.22. In the illustrated embodiment, copper is applied to the substrate as the material for the conductive pitch regions 2.11, 2.21; 3.11, 3.21. On the other hand, the substrate for the non-conductive pitch regions 2.12, 2.22; 3.12, 3.22 is uncoated. The arrangement with two pitch lines 2.1, 2.2; 3.1, 3.2 allows absolute determination of the angular position of each of the scale elements 2, 3. The outermost pitch line 2.2 of the first scale element 2 has the greatest number of pitch regions 2.21, 2.22 along its circumference, thereby providing the greatest resolution for measuring the angular position.

[0049] 1, the scanning element 1 and the scale elements 2, 3 are opposed to each other with an axial gap or air gap therebetween, so that in the event of a relative rotation between the scale elements 2, 3 and the scanning element 1, an inductive effect generates a signal in the receiving conductors 1.1121, 1.1141, 1.1221, 1.1241 that depends on the respective angular position. The prerequisite for generating a corresponding signal is that the excitation conductors 1.1111, 1.1131, 1.1151, 1.1211, 1.1231, 1.1251 each generate a time-varying electromagnetic excitation field in the region of the scanned pitch structure. In the illustrated embodiment, the excitation conductors 1.1111, 1.1131, 1.1151, 1.1211, 1.1231, 1.1251 are configured as a number of parallel, planar, current-carrying individual conductors. The scanning element 1 has an electronic circuit with electronic components 1.2 electrically connected to each other via layers E and F. The electronic circuit may include, for example, an ASIC module. The electronic circuit of the scanning element 1 functions not only as an evaluation element but also as an excitation control element, under whose control an excitation current is generated through the excitation conductors 1.1111, 1.1131, 1.1151, 1.1211, 1.1231, and 1.1251. Thus, the excitation conductors 1.1111, 1.1131, 1.1151, 1.1211, 1.1231, and 1.1251 are energized by a single excitation control element. Here, the first excitation line 1.111 and the second excitation line 1.121 are electrically connected in series.

[0050] When the excitation lines 1.111, 1.113, 1.115, 1.121, 1.123, and 1.125 are energized, a cylindrically or tubularly oriented electromagnetic field is generated around the excitation lines 1.1111, 1.1131, 1.1151, 1.1211, 1.1231, and 1.1251. The magnetic field lines of the resulting electromagnetic field extend around the excitation lines 1.111, 1.113, 1.115, 1.121, 1.123, and 1.125, and the direction of the magnetic field lines depends in a known manner on the direction of the current in the excitation lines 1.1111, 1.1131, 1.1151, 1.1211, 1.1231, and 1.1251. Eddy currents are induced in the conductive pitch regions 2.11, 2.21; 3.11, 3.21, respectively, resulting in a field modulation dependent on the angular position. Thus, the relative angular position can be measured by the receiving lines 1.112, 1.114, 1.122, 1.124, respectively. Pairs of receiving conductors 1.1121, 1.1141, 1.1221, 1.1241 are arranged within the receiving lines 1.112, 1.114, 1.122, 1.124, respectively, so that they provide signals 90° out of phase with each other, thereby enabling the direction of rotation to be determined. The signals generated by the receiving lines 1.112, 1.114, 1.122, 1.124 are further processed by part of the electronics 1.2, which forms the evaluation circuit.

[0051] The first and second shielding layers 1.13, 1.14 substantially prevent the two detector units 1.11, 1.12 from adversely affecting the measurement accuracy. In particular, they prevent unacceptably high levels of crosstalk signals and avoid excessive attenuation of the excitation field. Furthermore, they also prevent electromagnetic interference of the detector units 1.11, 1.12 from the electronics 1.2 or from external sources. [Explanation of symbols]

[0052] 1 scanning element 1.1 Printed circuit board 1.11 First detector unit 1.111 First excitation line 1.112 First receiving line 1.1121 first receiving conductor 1.113 Third excitation line 1.114 Third receiving line 1.1141 Third receiving conductor 1.12 Second detector unit 1.121 Second excitation line 1.122 Second receiving line 1.1221 Second receiving conductor 1.123 Fourth excitation wire 1.124 Fourth receiving line 1.1241 Fourth receiving conductor 1.13 First shield layer 1.14 Second shield layer 1.15 through hole 1.2 Electronic Components 2 First scale element 3 Second Scale Element A. First layer B. Second layer C. Sixth Layer D. Fifth Layer E. Third layer F. Fourth Layer D1 First diameter d2 Second diameter L1 First length L2 Second length M center plane R-axis U1 First gap U2 Second gap z Third direction λ1 First period length λ2 Second period length

Claims

1. A scanning element (1) for an inductive position measuring device, comprising a multilayer printed circuit board (1.1) and an electronic component (1.2), said printed circuit board (1.1) comprising: a first detector unit (1.11) having a first excitation line (1.111) and a first receiving line (1.112), said first detector unit (1.11) being arranged on a first layer (A) and a second layer (B) of said printed circuit board (1.1); a second detector unit (1.12) having a second excitation line (1.121) and a second receiving line (1.122), said second detector unit (1.12) being arranged on a third layer (E) and a fourth layer (F) of said printed circuit board (1.1); the printed circuit board (1.1) has a geometrical central plane (M) located between the first detector unit (1.11) and the second detector unit (1.12); the first receiving wire (1.112) and the second receiving wire (1.122) are arranged in a circumferential direction around an axis (R) perpendicular to the central plane (M); the first receiving line (1.112) includes a first receiving conductor (1.1121), the second receiving line (1.122) includes a second receiving conductor (1.1221), and the first receiving conductor (1.1121) and the second receiving conductor (1.1221) each have a periodic path; the first receiving line (1.112) has a first gap (U1) along its extension in the circumferential direction, the first gap (U1) being defined by the first receiving conductor (1.1121); the second receiving line (1.122) has a second gap (U2) along its extension in the circumferential direction, the second gap (U2) being defined by the second receiving conductor (1.1221); A scanning element, wherein the printed circuit board (1.1) has through holes (1.15), the through holes (1.15) being arranged both in the first gap (U1) and in the second gap (U2).

2. A scanning element (1) according to claim 1, The through-hole (1.15) electrically connecting the first detector unit (1.11) to the third layer (E) or the fourth layer (F), or A scanning element electrically connecting the second detector unit (1.12) with the first layer (A) or the second layer (B).

3. A scanning element (1) according to claim 1 or 2, The through-hole (1.15) is in electrical contact with one of the electronic components (1.2).

4. A scanning element (1) according to any one of claims 1 to 3, The through holes (1.15) are used as through hole vias, scanning element.

5. A scanning element (1) according to any one of claims 1 to 4, A scanning element, wherein the first gap (U1) extends in the circumferential direction by a first length (L1), and the first receiving conductor path (1.1121) has a periodic path with a first periodic length (λ1), where L1≧1 / 8·λ1.

6. A scanning element (1) according to claim 5, A scanning element, wherein the second gap (U2) extends in the circumferential direction by a second length (L2), and the second receiving conductor path (1.1221) has a periodic path with a second periodic length (λ2), where L2≧1 / 8·λ2.

7. A scanning element (1) according to any one of claims 1 to 6, A scanning element, wherein the first receiving conductor path (1.1121) has a periodic path with a first periodic length (λ1), and the second receiving conductor path (1.1221) has a periodic path with a second periodic length (λ2), the second periodic length (λ2) being equal to or greater than the first periodic length (λ1).

8. A scanning element (1) according to any one of claims 1 to 7, A scanning element, wherein the second detector unit (1.12) and at least one of the electronic components (1.2) are arranged on the same side of the printed circuit board (1.1).

9. A scanning element (1) according to claim 6 or 7, A scanning element, wherein the first detector unit (1.11) has a third receiving line (1.114) and the second detector unit (1.12) has a fourth receiving line (1.124).

10. A scanning element (1) according to claim 9, A scanning element, wherein the third receiving line (1.114) includes a third receiving conductor path (1.1141), the third receiving conductor path (1.1141) having a periodic path, the periodic length of the third receiving conductor path (1.1141) being smaller than the first periodic length (λ1) of the first receiving conductor path (1.1121).

11. A scanning element (1) according to claim 9 or 10, A scanning element, wherein the fourth receiving line (1.124) includes a fourth receiving conductor (1.1241), the fourth receiving conductor (1.1241) having a periodic path, the periodic length of the fourth receiving conductor (1.1241) being greater than the second periodic length (λ2) of the second receiving conductor (1.1221).

12. A scanning element (1) according to any one of claims 1 to 11, A scanning element, wherein the first detector unit (1.11) has a third excitation line (1.113) and the second detector unit (1.12) has a fourth excitation line (1.123).

13. A scanning element (1) according to any one of claims 1 to 12, The printed circuit board (1.1) includes a fifth layer (D) and a sixth layer (C), A scanning element, wherein a first shield layer (1.13) is disposed on the fifth layer (D), a second shield layer (1.14) is disposed on the sixth layer (C), and the through hole (1.15) penetrates the first shield layer (1.13) and the second shield layer (1.14).

14. 14. An inductive position measuring device comprising a scanning element (1) according to any one of claims 1 to 13, and a first scale element (2) and a second scale element (3), wherein the first scale element (2) and the second scale element (3) are arranged spaced apart on either side of the printed circuit board (1.1) in a third direction (z) oriented perpendicular to the central plane.

15. 15. An inductive position measuring device according to claim 14, An inductive position measuring device, wherein the first scale element (2) has a first diameter (D1), and the second scale element (3) has a second diameter (d2), and the first diameter (D1) is larger than the second diameter (d2).

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