Scanning probe, method, and system

Abstract

To provide a scanning probe, a method, and a system that reduce cross talk.SOLUTION: An inductive position detection configuration for stylus position measurement in a scanning probe 300 comprises a stylus position detection unit arranged along a central axis in the scanning probe 300. The stylus position detection unit includes a field generating coil configuration 360, an upper part axial direction detection coil configuration, an upper part rotation detection coil configuration, a lower part axial direction detection coil configuration, and a lower part rotation detection coil configuration. The field generating coil configuration 360 generates a changing magnetic flux, and a coil signal indicates a conductive disruptor element and / or the position of a stylus. A field generating coil coupling and crosstalk removing configuration is configured to couple signal processing and a control circuit to the field generating coil configuration 360 to provide a coil drive signal and reduce cross talk.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of U.S. patent application Ser. No. 17 / 135,672, filed December 28, 2020, entitled "INDUCTIVE POSITION DETECTION CONFIGURATION FOR INDICATING A MEASUREMENT DEVICE STYLUS POSITION AND INCLUDING COIL MISALIGNMENT COMPENSATION," which is incorporated herein by reference in its entirety. U.S. patent application Ser. No. 17 / 135,672 is a continuation-in-part of U.S. patent application Ser. No. 16 / 557,719, filed August 30, 2019, entitled "INDUCTIVE POSITION DETECTION CONFIGURATION FOR INDICATING A MEASUREMENT DEVICE STYLUS POSITION." U.S. Patent Application No. 16 / 557719 is a continuation-in-part of U.S. Patent Application No. 16 / 178295, filed November 1, 2018, entitled "INDUCTIVE POSITION DETECTION CONFIGURATION FOR INDICATING A MEASUREMENT DEVICE STYLUS POSITION."

[0002] The present disclosure relates to precision measurement, and more particularly to an inductive sensing arrangement for use in a probe used in a coordinate measuring machine. [Background technology]

[0003] A coordinate measuring machine (CMM) can obtain measurements of an inspected workpiece. One exemplary prior art CMM is described in U.S. Pat. No. 8,438,746, which is incorporated herein by reference in its entirety, and includes a probe for measuring the workpiece, a translation mechanism for moving the probe, and a controller for controlling its movement. A CMM with a surface scanning probe is described in U.S. Pat. No. 7,652,275, which is incorporated herein by reference in its entirety. As disclosed therein, a mechanical contact probe or an optical probe can scan the surface of a workpiece.

[0004] A CMM using a mechanical contact probe is also described in U.S. Pat. No. 6,971,183, which is incorporated herein by reference in its entirety. The probe disclosed therein includes a stylus having a surface contact portion, an axial translation mechanism, and a rotational translation mechanism. The axial translation mechanism includes a translation member that allows the contact portion to move in a central axis direction of the scanning probe (also referred to as the Z direction or axial direction). The rotational translation mechanism includes a rotational member that allows the contact portion to move perpendicular to the Z direction. The axial translation mechanism is nested within the rotational translation mechanism. The position of the contact portion and / or the surface coordinates of the workpiece are determined based on the displacement of the rotational member and the axial displacement of the translation member.

[0005] Inductive sensing technology is known to be environmentally robust and has various desirable sensing characteristics. It is known to use precision LVDTs and the like to measure the displacement or position of various internal components in mechanical contact probes similar to those described above. However, LVDTs and other known inductive sensors that are accurate enough for use in CMM probes can be rather large and cumbersome to implement, and the associated movement mechanisms and / or displacement detector arrangements can be relatively expensive and / or susceptible to various “cross-coupling” errors (e.g., due to imperfections in the general configuration and / or mechanism and / or detector). U.S. Pat. No. 4,810,966 (the '966 patent), incorporated herein by reference in its entirety, discloses a relatively planar and relatively economical inductive sensor arrangement capable of detecting the three-dimensional position of a nearby conductive target. However, the arrangement disclosed in the '966 patent has several design deficiencies with respect to providing the necessary accuracy and / or form factor to make it well suited for use in CMM scanning probes. That is, the configuration of the '966 patent lacks the advanced functionality and features necessary to provide a reasonable level of accuracy in modern measurement equipment such as CMM probes. Other problems associated with the use of known inductive sensing systems such as those outlined above in CMM probes include signal / response nonlinearities inherent in the system's displacement response, position errors due to imperfect assembly and alignment, and signal drift due to environmental effects on the mechanical and electrical components (e.g., due to temperature changes), crosstalk between various components, etc. Improved inductive sensing configurations for use in CMM probes are needed (e.g., displacement detector configurations that are less susceptible to such errors and / or are relatively inexpensive). Summary of the Invention [Means for solving the problem]

[0006] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0007] A scanning probe responsive in three axes is provided for use in a measuring machine (such as a CMM) The scanning probe comprises a stylus suspension, a stylus position detection section, signal processing and control circuitry, and a field generating coil coupling and crosstalk cancellation arrangement.

[0008] The stylus suspension comprises a stylus coupling portion coupled to a frame of the scanning probe and configured to be rigidly coupled to the stylus, and a stylus movement mechanism configured to enable axial movement of the stylus coupling portion along an axial direction and rotational movement of the stylus coupling portion about a center of rotation.

[0009] The stylus position detector is arranged along a central axis parallel to the axial direction and nominally aligned with the center of rotation and is based on an inductive detection principle. The stylus position detector includes a field generating coil arrangement having at least one field generating coil, an upper axial detector coil arrangement (TASCC) having at least one upper axial detector coil, a lower axial detector coil arrangement (BASCC) having at least one lower axial detector coil, N upper rotation detector coils (TRSC), and N lower rotation detector coils (BRSC), where N is an integer greater than 3. Note that "nominal" is a Japanese translation of "nominally" and may mean "nominal, nominal, formal, design," etc.

[0010] The disruptor arrangement provides a disruptor region and includes a conductive disruptor element disposed along a central axis within the disruptor movement volume. The disruptor element is coupled to the stylus suspension by a coupling arrangement and moves within the disruptor movement volume relative to an undeflected position in response to deflection of the stylus suspension. The disruptor element can be described as moving through an axial range of motion + / -Rz in response to axial movement and moving through respective ranges of motion + / -Rx and + / -Ry along orthogonal X and Y directions generally perpendicular to the axial direction in response to rotational movement. The field-generating coil arrangement generates a varying magnetic flux generally along the axial direction within the disruptor movement volume in response to a coil drive signal.

[0011] The signal processing and control circuitry is operatively connected to the coils of the stylus position detection section to provide the coil drive signals, and is configured to receive signals from the receive coil section comprising respective signal components provided by the respective rotational and axial detection coils (i.e., the upper axial detection coil, the lower axial detection coil, the upper rotational detection coil, and the lower rotational detection coil), and is further configured to output signals indicative of the axial and rotational positions of at least one of the disruptor element or the stylus relative to the frame of the scanning probe.

[0012] The field-generating coil coupling and crosstalk cancellation arrangement is configured to couple the signal processing and control circuitry to the at least one field-generating coil for providing a coil drive signal and to reduce crosstalk that would otherwise occur if the at least one field-generating coil were directly connected to the signal processing and control circuitry without the field-generating coil coupling and crosstalk cancellation arrangement.

[0013] In some embodiments, the field-generating coil coupling and crosstalk cancellation arrangement has a first upper branch and a first lower branch.

[0014] In some such embodiments, the at least one field-generating coil comprises a first field-generating coil defining a first field-generating coil plane that is orthogonal to the central axis and passes through the first field-generating coil, such that the first upper branch and the first lower branch of the field-generating coil coupling and crosstalk cancellation structure are positioned above and below the first field-generating coil plane, respectively.

[0015] In some such embodiments, 2 The Upper Branch and the 2 The subordinate branch of 2 symmetrical with respect to the plane of the field-generating coil; a plurality of parallel-connected capacitors configured to pass similar currents above and below the plane of the first field-generating coil; At least one of being part of a mirrored current distribution arrangement, being configured to pass similar currents above and below the plane of the first field-generating coil at approximately equal distances and similar relative X and Y coordinate locations, respectively, or being connected in parallel.

[0016] In some such embodiments, the first upper branch comprises a first upper capacitor and the first lower branch comprises a first lower capacitor, the first upper capacitor and the first lower capacitor being connected in parallel.

[0017] In some such embodiments, the at least one field-generating coil comprises a second field-generating coil defining a second field-generating coil plane orthogonal to the central axis and passing through the second field-generating coil, such that the first and second field-generating coils correspond to upper and lower field-generating coils, respectively, and the field-generating coil coupling and crosstalk cancellation arrangement comprises a second upper branch and a second lower branch disposed above and below the second field-generating coil plane, respectively. In some such embodiments, the first upper branch comprises a first upper capacitor and the first lower branch comprises a first lower capacitor, the first upper capacitor and the first lower capacitor being connected in parallel. Also, the second upper branch comprises a second upper capacitor and the second lower branch comprises a second lower capacitor, the second upper capacitor and the second lower capacitor being connected in parallel.

[0018] In some embodiments, the field generating coil coupling and crosstalk cancellation arrangement comprises: a plurality of parallel-connected capacitors configured to pass similar currents above and below the plane of the first field-generating coil; In some such embodiments, the mirrored current distribution configuration comprises a pair of capacitors connected in parallel. In some such configurations, the mirrored current distribution configuration comprises a middle current branch having current flow in a first direction; Each capacitor is composed of a plurality of capacitors, A three-current branch structure is provided, including an upper current branch and a lower current branch each coupled to the middle current branch and having current flow in a second direction generally opposite the first direction.

[0019] In some embodiments, the at least one field-generating coil comprises a first field-generating coil. In some such embodiments, the field-generating coil coupling and crosstalk cancellation arrangement comprises a first conductive coupling comprising a first conductor coupling the first field-generating coil to the signal processing and control circuitry, thereby providing a first twist arrangement that cancels the contribution of the first conductor.

[0020] In some such embodiments, the field-generating coil coupling and crosstalk cancellation arrangement comprises a first conductive coupling portion coupling the first field-generating coil to the signal processing and control circuitry, and a first conductive shield disposed proximate the first field-generating coil and the first conductive coupling portion to shield the first conductive coupling portion. In some such embodiments, the field-generating coil coupling and crosstalk cancellation arrangement further comprises a second conductive shield at a second position relative to the central axis, the first conductive shield at a first position relative to the central axis, and the first and second positions being symmetrical about the central axis.

[0021] In some embodiments, the method includes moving a scanning probe along a surface of the workpiece as disclosed herein and generating three-dimensional position information based on inductive detection signals generated by the scanning probe as the scanning probe moves along the surface of the workpiece.

[0022] In some embodiments, a system comprises a scanning probe as disclosed herein, a drive mechanism, and a mount configured to couple the scanning probe to the drive mechanism.

[0023] Known inductive sensors that use nominally planar sensing elements are too inaccurate for precision scanning probe applications. In contrast, inductive sensors utilizing nominally planar sensing elements configured according to various principles disclosed herein provide robust signal sets that can be used to provide sufficient accuracy for precision scanning probe applications. In particular, embodiments and / or configurations such as those outlined above can provide particularly advantageous signal components with respect to removing or correcting certain signal errors and / or crosstalk (e.g., signal cross-coupling) errors that previously limited the accuracy of position determination in known, economical three-dimensional position indicators based on inductive sensing. [Brief explanation of the drawings]

[0024] [Figure 1] 1 illustrates various exemplary components of a measurement system including a CMM utilizing a scanning probe as disclosed herein; [Figure 2] FIG. 1 is a block diagram showing various components of a scanning probe coupled to a CMM to provide rotational and axial position signals. [Figure 3] 1A and 1B are diagrams illustrating a portion of a first exemplary embodiment of a stylus suspension coupled to a stylus and a first exemplary embodiment of a stylus position detector for detecting the position of the stylus suspension. [Figure 4] FIG. 4 shows a cross section of one embodiment of the stylus suspension of FIG. 3 contained within the body frame of a scanning probe; [Figure 5] 5 is a partial schematic isometric view of an alternative embodiment of the stylus position detector shown in FIGS. 3 and 4, highlighting particular features in accordance with principles disclosed herein; FIG. [Figure 6]FIG. 6 is a partial schematic isometric view of certain components of the stylus position detector shown in FIG. 5, illustrating their connection to a block diagram of one exemplary embodiment of processing and control circuitry according to the principles disclosed herein. [Figure 7A] 5A-5C depict embodiments of "four complementary pairs" of receive coil section and disruptor element configuration patterns according to principles disclosed herein that can be used in the various embodiments of stylus position detection sections shown in FIGS. 3 and / or 4. [Figure 7B] 5A-5C depict embodiments of "four complementary pairs" of receive coil section and disruptor element configuration patterns according to principles disclosed herein that can be used in the various embodiments of stylus position detection sections shown in FIGS. 3 and / or 4. [Figure 7C] 5A-5C depict embodiments of "four complementary pairs" of receive coil section and disruptor element configuration patterns according to principles disclosed herein that can be used in the various embodiments of stylus position detection sections shown in FIGS. 3 and / or 4. [Figure 7D] 5A-5C depict embodiments of "four complementary pairs" of receive coil section and disruptor element configuration patterns according to principles disclosed herein that can be used in the various embodiments of stylus position detection sections shown in FIGS. 3 and / or 4. [Figure 7E] 5A-5C depict embodiments of "four complementary pairs" of receive coil section and disruptor element configuration patterns according to principles disclosed herein that can be used in the various embodiments of stylus position detection sections shown in FIGS. 3 and / or 4. [Figure 8A] 5A-5C are diagrams illustrating embodiments of "three (or six) complementary pairs" of receive coil section and disruptor element configuration patterns according to principles disclosed herein that can be used in the various embodiments of stylus position detection sections shown in FIGS. 3 and / or 4. [Figure 8B]5A-5C are diagrams illustrating embodiments of "three (or six) complementary pairs" of receive coil section and disruptor element configuration patterns according to principles disclosed herein that can be used in the various embodiments of stylus position detection sections shown in FIGS. 3 and / or 4. [Figure 8C] 5A-5C are diagrams illustrating embodiments of "three (or six) complementary pairs" of receive coil section and disruptor element configuration patterns according to principles disclosed herein that can be used in the various embodiments of stylus position detection sections shown in FIGS. 3 and / or 4. [Figure 8D] 5A-5C are diagrams illustrating embodiments of "three (or six) complementary pairs" of receive coil section and disruptor element configuration patterns according to principles disclosed herein that can be used in the various embodiments of stylus position detection sections shown in FIGS. 3 and / or 4. [Figure 8E] 5A-5C are diagrams illustrating embodiments of "three (or six) complementary pairs" of receive coil section and disruptor element configuration patterns according to principles disclosed herein that can be used in the various embodiments of stylus position detection sections shown in FIGS. 3 and / or 4. [Figure 8F] 5A-5C are diagrams illustrating embodiments of "three (or six) complementary pairs" of receive coil section and disruptor element configuration patterns according to principles disclosed herein that can be used in the various embodiments of stylus position detection sections shown in FIGS. 3 and / or 4. [Figure 9A] 10A and 10B illustrate a portion of an exemplary embodiment of a stylus position detector for detecting the position of a stylus suspension. [Figure 9B] 10A and 10B illustrate a portion of an exemplary embodiment of a stylus position detector for detecting the position of a stylus suspension. [Figure 10] 9C is a partial schematic isometric view of an alternative embodiment of the stylus position detector shown in FIGS. 9A and 9B, highlighting certain features in accordance with principles disclosed herein; FIG. [Figure 11]11 is a partial schematic isometric view of an alternative embodiment of the stylus position detector shown in FIG. 10, highlighting certain features in accordance with principles disclosed herein. [Figure 12A] 10A and 10B illustrate a portion of an exemplary embodiment of a stylus position detector for detecting the position of a stylus suspension. [Figure 12B] 10A and 10B illustrate a portion of an exemplary embodiment of a stylus position detector for detecting the position of a stylus suspension. [Figure 13A] 1 is a partial schematic isometric view of an exemplary embodiment of a stylus position detector highlighting particular features in accordance with principles disclosed herein; [Figure 13B] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 13C] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 13D] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 13E] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 13F] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 14A] 10 illustrates exemplary frequency shift and off-axis crosstalk characteristics associated with various embodiments of a stylus position detector. [Figure 14B] 10 illustrates exemplary frequency shift and off-axis crosstalk characteristics associated with various embodiments of a stylus position detector. [Figure 14C] 10 illustrates exemplary frequency shift and off-axis crosstalk characteristics associated with various embodiments of a stylus position detector. [Figure 14D]10 illustrates exemplary frequency shift and off-axis crosstalk characteristics associated with various embodiments of a stylus position detector. [Figure 15A] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 15B] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 15C] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 16] 1 is a partial schematic isometric view of an exemplary embodiment of a stylus position detector highlighting particular features in accordance with principles disclosed herein; [Figure 17A] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 17B] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 18A] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 18B] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 18C] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 19] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 20] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 21] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 22] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 23] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; [Figure 24] 1 is a schematic diagram illustrating a portion of an exemplary embodiment of a stylus position detector, highlighting particular features in accordance with principles disclosed herein; DETAILED DESCRIPTION OF THE INVENTION

[0025] 1 is a diagram illustrating various exemplary components of a measurement system 100 including a CMM 200 utilizing a scanning probe 300 as disclosed herein. The measurement system 100 includes an operation unit 110, a motion controller 115 for controlling the movement of the CMM 200, a host computer 120, and the CMM 200. The operation unit 110 is coupled to the motion controller 115 and may include a joystick 111 for manually operating the CMM 200. The host computer 120 is coupled to the motion controller 115 and operates the CMM 200 and processes measurement data of the workpiece W. The host computer 120 includes input means 125 (e.g., a keyboard, etc.) for inputting, for example, measurement conditions, and output means 130 (e.g., a display, printer, etc.) for outputting, for example, measurement results.

[0026] CMM 200 includes a drive mechanism 220 disposed on base plate 210 and a mount 224 for mounting scanning probe 300 to drive mechanism 220. Drive mechanism 220 includes X-axis, Y-axis, and Z-axis slide mechanisms 222, 221, and 223, respectively, for moving scanning probe 300 in three dimensions. A stylus 306 attached to the end of scanning probe 300 includes a contact portion 348. As described in more detail below, stylus 306 is attached to a stylus suspension of scanning probe 300, which allows contact portion 348 to freely change its position in three directions as contact portion 348 moves along a measurement path on the surface of workpiece W.

[0027] Figure 2 is a block diagram showing various components of a scanning probe 300 coupled to a CMM 200 and providing rotational (e.g., X, Y) and axial (e.g., Z) position signals. The scanning probe 300 comprises a probe body 302 (e.g., comprising a frame) incorporating a stylus suspension 307 and a stylus position detection portion 311 (i.e., the stylus suspension 307 is coupled to the frame of the scanning probe 300). The stylus suspension 307 comprises a stylus coupling portion 342 and a stylus movement mechanism 309. The stylus coupling portion 342 is rigidly coupled to a stylus 306. The stylus movement mechanism 309 is configured to allow axial movement of the stylus coupling portion 342 and attached stylus 306 along an axial direction, and rotational movement of the stylus coupling portion 342 and attached stylus 306 about a center of rotation, as described in more detail below with respect to Figures 3 and 4. The scanning probe 300 includes signal processing and control circuitry 380 which is connected to the stylus position detector 311 to control its operation and to perform associated signal processing, as will be explained in more detail below.

[0028] As shown in FIG. 2 , the stylus position detection section 311 uses an inductive detection principle and includes a receive coil section 370, a field-generating coil arrangement 360, and a disruptor element 351 (which is part of a disruptor arrangement 350 and may comprise multiple sections in some embodiments). The receive coil section 370 may include a rotational detection coil section (also called a rotational detection coil) RSC and an axial detection coil arrangement ASCC. Briefly, the moving disruptor element 351 (or, more generally, the disruptor arrangement 350) causes position-dependent changes in the varying magnetic field (variable magnetic flux) generated by the field-generating coil arrangement 360. The receive coil section 370 responds to the varying magnetic field and changes therein caused by the disruptor element 351. In particular, the rotational detection coil section RSC outputs at least first and second rotational signal components RSigs indicative of the rotational position (e.g., X and Y position signals) of the stylus coupling section 342 on corresponding signal lines, as described in more detail below with reference to, for example, Figures 3, 5, and 6. And, the axial detection coil arrangement ASCC outputs one or more axial signal components ASigs indicative of the axial position (e.g., Z position signal) of the stylus coupling section 342 on corresponding signal lines. In various embodiments, the signal processing and control circuitry 380 can receive the rotational signal components RSigs and the axial signal components ASigs and perform various levels of associated signal processing in various embodiments. For example, in one embodiment, the signal processing and control circuitry 380 can combine and / or process the signal components from the various receiving coils in various relationships and provide the results in a desired output format as rotational and axial position signal outputs RPSOut and APSOut via the mounting section 224. One or more receivers (e.g., CMM 200, motion controller 115, host computer 120, etc.) may receive the rotational and axial position signal outputs RPSOut and APSOut, and one or more associated signal processing and control units may be utilized to determine the three-dimensional position of the contact portion of the stylus coupling portion 342 and / or attached stylus 306 as the contact portion 348 moves along the surface of the workpiece W being measured.

[0029] FIG. 3 is a partial schematic diagram illustrating a portion of a first exemplary embodiment of a stylus suspension 407 coupled to a stylus 406, along with a partial schematic cross-sectional view of the first exemplary embodiment of the stylus suspension 407 and / or stylus position detection portion 411 for detecting the position of the stylus 406. (Note that the stylus position detection portion 411 is disposed along a central axis CA that is parallel to the axial direction (Z direction) and nominally aligned with a center of rotation RC, as shown in FIG. 3.) It will be understood that certain numbered components 4XX in FIG. 3 correspond to and / or have similar operation to similarly numbered corresponding components 3XX in FIG. 2 and can be understood by analogy thereto and otherwise described below. This numbering scheme, indicating components of similar design and / or function, also applies to FIGS. 4-8F below. As shown in FIG. 3, the stylus suspension 407 includes a stylus-moving mechanism 409 and a stylus coupling portion 442. The stylus coupling portion 442 is configured to be rigidly coupled to a stylus 406 having a contact portion 448 for contacting a surface S of a workpiece W (not shown).

[0030] As will be described in more detail below with respect to Figure 4, the stylus movement mechanism 409 is mounted to the frame of the scanning probe and is configured to allow axial and rotational movement of the stylus coupling portion 442 and attached stylus 406 so that the contact portion 448 can vary its position in three directions along the shape of the surface S. For purposes of illustration, the vertical and horizontal directions in the plane of the paper in Figure 3 are defined as the Z and Y directions, respectively, and the direction normal to the plane of the paper is defined as the X direction. The direction of the central axis CA of the scanning probe 300, also referred to as the axial direction, coincides with the Z direction in this figure.

[0031] 3 shows the rotational movement portion of the stylus movement mechanism 409, which includes a rotating member 436, a bending element 440, and a moving member 412 disposed within the rotating member 436. As described in more detail below in FIG. 4, the bending element 440 enables rotational movement of the rotating member 436 about a center of rotation RC. As described in more detail below, in various embodiments, rotational detection coils TRSCi and BRSCi (where i is an index integer that identifies a particular coil) and the stylus position detection portion 411 can detect the rotational position of the disruptor element 451, thereby detecting the rotational position (e.g., in the X and Y directions) of the moving member 412, and axial detection coil arrangements (also referred to as axial detection coils) TASCC and BASCC can detect the axial position of the disruptor element 451, thereby detecting the axial position (e.g., in the Z direction) of the moving member 412.

[0032] As shown in Figure 3, a first exemplary embodiment of the stylus position detection unit 411 comprises a disruptor element 451 (or, more generally, a disruptor arrangement 450) coupled to a moving member 412 and moving relative to a frame of the scanning probe (e.g., a frame included as part of the scanning probe body) within a disruptor movement volume MV located between the upper and lower coil substrates 471T and 471B, respectively. As shown in Figure 3, the moving member 412 extends through and moves within a hole 472 located along a central axis CA of the lower coil substrate (471B) (i.e., the moving member 412 passes through a hole 472 located in the lower coil substrate 471B along the central axis CA and extends approximately along the central axis CA). The attached disruptor element 451 moves within the disruptor movement volume MV relative to an undeflected position UNDF in response to deflections of the stylus suspension 407 and the moving member 412.

[0033] Various other components of the stylus position detection section 411, such as the receive coil section 470 and the field generating coil arrangement 460, may be fixed relative to the frame unless otherwise noted. In the embodiment shown in FIG. 3, the field generating coil arrangement 460 comprises a single planar field generating coil (also referred to as a field generating coil section) 461 disposed approximately in the midplane of the disruptor movement volume MV and nominally planar and perpendicular to the central axis CA. As outlined above with reference to FIG. 2, the receive coil section 470 may generally comprise a rotational detection coil section (also referred to as a rotational detection coil) RSC and an axial detection coil arrangement ASCC. The rotational position detection arrangement (rotational detection coil section) RSC generally comprises upper and lower rotational detection coils TRSCi and BRSCi. Only two upper rotational detection coils TRSC1 and TRSC2 and two lower rotational detection coils BRSC1 and BRSC2 are shown in the cross section shown in FIG. 3. These rotational detection coils may provide signal components indicative of the position of the disruptor element 451 along the Y direction. In particular, those signal components vary with, and are therefore indicative of, the amount of displacement ΔY of the disruptor element 451 along the Y-direction. The displacement ΔY determines the amount of relative “overlap” between the disruptor element 451 and the various rotational detection coils TRSCi and BRSCi, thereby determining the amount of coupling to the varying magnetic field generated by the field generating coils 461 (which determines the resulting signal components). Other rotational detection coils (not shown) can provide signal components indicative of the position of the disruptor element 451 along the X-axis direction. The signal components of the various rotational detection coils may also be undesirably sensitive to their local “operating gap” OG relative to the disruptor element 451, as shown in FIG. 3 for the upper rotational detection coil TRSC2. However, such undesirable gap sensitivity can be substantially eliminated or compensated for in accordance with various principles disclosed herein, as further described below.

[0034] The axial detector coil arrangement ASCC generally comprises an upper axial detector coil arrangement TASCC and a lower axial detector coil arrangement BASCC. In the embodiment shown in FIG. 3, the upper axial detector coil arrangement TASCC comprises a single upper axial detector coil at least partially surrounding the central axis CA, and the at least one lower axial detector coil comprises a single lower axial detector coil at least partially surrounding the central axis, as shown. These axial detector coils are always fully "overlapped" by the disruptor element 451. Thus, their signal components are nominally responsive only to, and indicative of, the position of the disruptor element 451 along the axial or Z direction. The generation of the various signal components is described in more detail below with reference to FIGS. 5 and 6.

[0035] Similar to the operation outlined above with reference to FIG. 2, during operation, the moving disruptor element 451 induces position-dependent local variations in the axially varying magnetic field generated by the field generating coils 461. The receive coil section 470, as described above with reference to FIG. 2 and in further detail below, responds to the varying magnetic field induced by the disruptor element 451 and variations therein and outputs rotational signal components RSigs and axial signal components ASigs that may be processed to determine the rotational position (e.g., Y and X positions, and corresponding signals) and axial position (e.g., Z position) of the disruptor element 451. It will be appreciated that the position of the disruptor element 451 is related by known geometry to the position of the stylus coupling portion 442 and / or its contact portion 448. For example, for small rotation angles, for an illustrated movement or displacement ΔY of the disruptor element 451 along the Y direction away from null (e.g., from the undeflected position UNDF), ΔY=Hθ Y (Formula 1)

[0036] where H is the distance from the center of rotation RC to the nominal plane of the disruptor element 451, and θ Yis the slope of the rotational movement of the rotating member 436 (and moving member 412) in a plane parallel to the Y direction (i.e., rotation about an axis parallel to the X axis at the center of rotation RC). In various embodiments, when larger rotation angles are used, accurate similar expressions for larger rotation angles may be used as known in the art. The slope component θ of the rotational movement Y Y is the Y-direction movement or displacement Y of the contact portion 448 of the stylus 406 away from the null (e.g., corresponding to the undeflected position UNDF) in relation to STYLUS can be approximated as follows: ΔY STYLUS =θ Y *(h S +l S ) (Formula 2)

[0037] where h S is the distance from the end of the stylus coupling portion 442 to the center of rotation RC, and l S is the length of the stylus 406. Combining Equations 1 and 2, the ratio of the displacement ΔY of the disruptor element 451 to the displacement of the contact portion 448 in the Y direction can be approximated as: ΔY / ΔY STYLUS = H / (h S +l S ) (Formula 3)

[0038] It will be understood that the translation component of the X coordinate is similar to the above equation and will not be described in further detail herein. S can utilize equations (e.g., for system trigonometry) to determine the XY position of the contact 448 based on the XY detection spot position. In terms of Z coordinate displacement or position component, the Z displacement ΔZ of the stylus contact (e.g., contact 448) STYLUS The displacement ΔZ (not shown) of the disruptor element 451 along the axial or Z direction away from the null (e.g., corresponding to the undeflected position UNDF) relative to can be approximated as: ΔZ / ΔZ STYLUS ≒ 1 (Equation 4)

[0039] FIG. 4 is a partial schematic diagram illustrating an embodiment of a stylus position detection portion 511 similar to the stylus position detection portion 411 shown in FIG. 3 , as well as a cross section of an embodiment of a stylus suspension 407′ that can be used as the stylus suspension 407 shown in FIG. 3 , and a signal processing and control circuit 480. The above components are shown contained within a frame 408 of the probe body 402 of the scanning probe 400. The upper and lower coil boards 571T, 571B and the field-generating coils 561 of the stylus position detection portion 511 or their substrates (e.g., printed circuit boards) are positioned for proper operation in the scanning probe 400 using an alignment and mounting portion 417 or other known techniques. Various signal connections associated with the stylus position detection portion 511 may be provided by connectors (e.g., flex prints and / or wire connections) 419, etc., in accordance with known techniques. In some embodiments, some or all of the signal processing and control circuitry 480 may be provided as a separate circuit assembly, as shown in FIG. 4 . In other embodiments, some or all of the signal processing and control circuitry 480 may be combined on board the stylus position detection portion 511, if desired.

[0040] As shown in Figure 4, the stylus suspension 407' comprises a stylus movement mechanism 409 and a stylus coupling portion 442 coupled to the stylus 406. The stylus movement mechanism 409 comprises a moving member 412, a rotating member 436, a flexure element 440 coupled to the frame 408 to support and allow rotational movement of the rotating member 436, and flexure elements 414 and 415 (i.e. referred to as first flexure elements) that support and couple the moving member 412 to the rotating member 436 to allow axial movement of the moving member 412. The scanning probe 400 comprises a stylus position detection portion 511, the components and operation of which are described in more detail below with reference to Figure 5, for determining the position and / or movement of the stylus movement mechanism 409 and / or a contact portion 448 of the stylus 406.

[0041] The flexure element 440 (i.e., referred to as the second flexure element) can be disposed between the respective planes of the pair of flexure elements 414 and 415 (i.e., referred to as the first flexure elements) in the axial direction O. Appropriate flexure designs for the flexure elements 414, 415, and 440 can be determined according to principles known in the art. For example, one possible embodiment is shown in co-pending, commonly assigned U.S. patent application Ser. No. 14 / 973,376, entitled "Measurement Device With Multiplexed Position Signals," filed December 17, 2015, and incorporated herein by reference in its entirety. The rotating member 436 can have a shape symmetrical with respect to the second flexure element 440 and can integrally comprise two ring portions 436A, two connecting portions 436B, and one cylindrical portion 436C. The peripheries of the first flexure elements 414 and 415 are fixed to the ring portion 436A. Connecting portion 436B extends inside ring portion 436A to connect to hollow cylindrical portion 436C. First bending elements 414 and 415 may be positioned at symmetrical distances relative to second bending element 440, although such an embodiment is exemplary only and not limiting.

[0042] An axial movement mechanism 410 comprising a movement member 412 is supported inside the rotating member 436, and the rotating member 436 and the axial movement mechanism 410 together form a movement module that is part of the stylus movement mechanism 409. The axial movement mechanism 410 enables the contact portion 448 to move in the axial direction O. The rotational movement mechanism 434 comprising the rotating member 436 enables the contact portion 448 of the stylus 406 to move transversely (e.g., approximately perpendicularly) to the axial direction O by rotational movement about a rotation center RC.

[0043] The moving member 412 integrally comprises a lower portion 412A, a rod portion 412B, and an upper portion 412C. As generally described above with reference to FIG. 3 and described in more detail below with respect to the stylus position detection portion 511 shown in FIG. 5, a disruptor element 551 attached to the upper portion 412C of the moving member 412 functions as both a rotational and axial position indicating element. The rod portion 412B is disposed between a pair of first bending elements 414 and 415. The rod portion 412B is housed in the rotating member 436. The lower portion 412A is formed below the rod portion 412B, and a stylus coupling portion 442 (e.g., a flange member) is attached to the lower portion 412A. A flange portion 444 is provided for mounting the stylus 406. The flange portion 444 and the stylus coupling portion 442 together may provide a removable coupling mechanism (e.g. a kinematic joint or coupling of a known type) that allows for repeatable positioning and disconnection between various styli 406 and the stylus coupling portion 442 (e.g. in the event of a collision that dislodges the stylus, or when intentionally changing styli).

[0044] Figure 5 is a partial schematic isometric view of an alternative embodiment of a stylus position detector 511' similar to the stylus position detector 511 shown in Figure 4, highlighting certain features in accordance with the principles disclosed herein. Stylus position detectors 511' and 511 are similar except for differences in field-generating coil arrangement 560, as described further below. It will be understood that in general, stylus position detector 511' includes certain components similar to those of stylus position detectors 311, 411 and 511 of Figures 2, 3 and 4, and operate similarly except as otherwise described below.

[0045] In the embodiment shown in FIG. 5, the stylus position detection section 511 ′ comprises a receive coil section 570 , a disruptor arrangement 550 comprising disruptor elements 551 , and a field generating coil arrangement 560 .

[0046] In various embodiments, the disruptor element 551 (or, more generally, the disruptor structure 550) may comprise a conductive plate or loop, or parallel conductive plates or loops (e.g., provided on two sides of a printed circuit board and patterned using printed circuit board fabrication techniques), or any other desired operating structure that provides a disruptor area (e.g., an interior area thereof). The disruptor element 551 is disposed along a central axis CA of the disruptor movement volume MV between the upper coil substrate 571T and the lower coil substrate 571B, and is coupled to the stylus suspension 507 by a coupling structure (e.g., comprising the moving member 512). For purposes of explanation, the disruptor element 551 may be described as moving relative to an undeflected position shown in FIG. 5 (see undeflected position UNDF in FIG. 3 ) in response to deflection of the stylus suspension 507 and / or the stylus 506 and / or the moving member 512. The disruptor element may be described as moving in response to axial motion through an axial range of motion of + / -Rz with displacement increments ΔZ, and in response to rotational motion through an axial range of motion of + / -Rx and + / -Ry with displacement increments ΔX and ΔY along orthogonal X and Y directions, respectively, orthogonal to the axial (Z) direction. Specified or expected ranges of motion are described in more detail below.

[0047] The receive coil section 570 may comprise a planar upper coil substrate 571T comprising N upper rotating detector coils TRSC (e.g., N=4, TRSC1-TRSC4) and an upper axial detector coil arrangement TASCC (e.g., comprising a single illustrated individual coil in this embodiment), and a planar lower coil substrate 571B comprising N lower rotating detector coils BRSC (e.g., N=4, BRSC1-BRSC4) and a lower axial detector coil arrangement BASCC (e.g., comprising a single illustrated individual coil in this embodiment). The upper and lower coil substrates 571T and 571B are mounted in fixed relationship to the frame of the scanning probe, with the lower coil substrate closer to the stylus 506 and / or stylus suspension 507. The upper and lower coil substrates 571T and 571B are nominally parallel to each other and nominally perpendicular to and spaced apart along the central axis CA, and a disruptor moving volume MV may be disposed between them. While the various detection coils shown in FIG. 5 are represented by "closed loops" for ease of explanation, it will be understood that all coils comprise windings or conductors having first and second connected ends configured to act as one or more inductively coupled "turns" (e.g., as represented in FIG. 6).

[0048] The field-generating coil arrangement (e.g., field-generating coil arrangement 560) generally comprises at least one first field-generating coil positioned proximate to the disruptor movement volume MV and nominally planar and orthogonal to the central axis CA. In contrast to the single planar field-generating coil 461 in the embodiment shown in Figure 3 (which is located approximately in the mid-plane of the disruptor movement volume MV), in the embodiment shown in Figure 5, the field-generating coil arrangement 560 comprises a pair of planar field-generating coils 561T and 561B (located on upper and lower coil substrates 571T and 571B, respectively) positioned approximately equidistant from the mid-plane of the disruptor movement volume MV along the central axis CA and nominally planar and orthogonal to the central axis CA. Generally speaking, either field-generating coil configuration 460 or 560 can be used in receive coil section 570 (or other receive coil sections disclosed herein) if the field-generating coil configuration comprises at least a first field-generating coil configured such that the projection of its (i.e., of the first field-generating coil) coil area along the axial direction (Z direction) encompasses conductive plates or loops that provide the disruptor area of ​​disruptor configuration 550 (e.g., of disruptor element 551) and the coil areas of all rotational and axial detection coils RSCi and ASCC disposed on upper and lower coil substrates 571T and 571B (i.e., the projection of the coil area of ​​the first field-generating coil along the axial direction encompasses conductive plates or loops that provide the disruptor area and the coil areas of all rotational and axial detection coils RSCi and ASCC disposed on the coil substrate configuration). In such a case, the field generating coil arrangement is configured to generate a varying magnetic flux generally along an axial direction within the disruptor movement volume MV in response to the coil drive signals, as desired for operation of the stylus position detection portion 511'.The various field-generating coils shown in FIG. 5 are represented for ease of explanation as one single "closed loop" comprising a wide, flat conductive trace (with edges shown), but it will be understood that in an actual device (e.g., as represented in FIG. 6 ) all coils will comprise windings or conductors having first and second connection ends and will be configured to operate as one or more field-generating "turns."

[0049] As shown in FIG. 5, the projection of the disruptor element 551 along the axial direction through the internal coil region of the upper axial detector coil arrangement TASCC (e.g., as shown by the thin dashed line PRJ in FIG. 5) defines an upper axial detector overlap region TASOA (indicated by the dot pattern filling that internal coil region). Similarly, the projection of the disruptor element 551 along the axial direction through the internal coil region of the lower axial detector coil arrangement BASCC defines a lower axial detector overlap region BASOA (indicated by the dot pattern filling that internal coil region). Similarly, the projection of the disruptor element 551 along the axial direction through the internal coil region of each upper rotating detector coil TRSCi (e.g., TRSC1-TRSC4), where i is an individual coil identification index ranging from 1 to N, defines a respective upper rotating coil detector overlap region TRSCOAi (e.g., TRSCOA1-TRSCOA4). As shown by the dot patterns filling the various respective overlap regions in FIG. 5, the projection of the disruptor element 551 along the axial direction through the internal coil region of each lower rotating detection coil BRSCi (e.g., BRSC1-BRSC4) defines a respective lower rotating coil detection overlap region BRSCOAi (e.g., TRSCOA1-TRSCOA4).

[0050] Regarding the axial position detection in the stylus position detection unit (e.g., 511′), In accordance with the principles described and claimed herein, the receive coil sections (e.g., 570) and disruptor elements (e.g., 551) are generally configured to provide upper and lower axial detection overlap areas, TASOA and BASOA, respectively, where the respective amounts of overlap, TASOA and BASOA, do not vary with or depend on the position of the disruptor element 551 within its operating ranges of motion, + / -Rz, + / -Rx, and + / -Ry. (It will be understood that for a particular scanning probe, the operating range of motion will be defined or specified, if necessary, in combination with the configuration of the probe's particular stylus position detection sections to meet this requirement.) In this manner, the signal components generated by the upper and lower axial detection coil arrangements, TASCC and BASCC, are nominally independent of rotational motion (i.e., the position of the disruptor element 551 along the X and Y directions) and are nominally sensitive only to changes in "proximity" or gap with the disruptor element 551. Note that the change in "proximity" or gap varies with the axial (Z) position or displacement ΔZ of the disruptor element 551. During operation, current induced in the disruptor element 551 by the changing magnetic field of the field generating coil arrangement 560 causes an opposing magnetic field. Generally, as the disruptor element 551 moves upward along the axial (Z) direction of FIG. 5, the opposing magnetic field couples more strongly to the upper axial detection coil arrangement TASCC, reducing its signal component resulting from the changing magnetic field. Conversely, the opposing magnetic field couples more weakly to the lower axial detection coil arrangement BASCC, increasing its signal component resulting from the changing magnetic field. By convention used in this disclosure, a signal component SIGTA SCC may be referred to as the signal component resulting from a particular upper axial detection coil arrangement (or coil), such as TASCC.

[0051] It can be seen that in the undeflected position UNDF, the net signal components SIGTASCC and SIGBASCC are approximately balanced. For small displacements ΔZ, such as those expected during operation, the net signal components SIGTASCC and SIGBASCC can vary approximately linearly and inversely relative to one another. Specific considerations related to the degree of such signal nonlinearity are discussed further below. In one embodiment, the axial displacement or position ΔZ can be indicated by or correspond to a signal relationship. ΔZ = function [(SIGBASCC-SIGTASCC) / (SIGBASCC+SIGTASCC)] (Equation 5)

[0052] This signal relationship is merely exemplary and not limiting. In various embodiments, this signal relationship may be adjusted or compensated for by additional calibration or signal processing operations, as needed, including operations to reduce the effects of geometric and / or signal cross-coupling between various displacement directions or signal components. In various embodiments, the upper axial detection coil configuration may include at least one upper axial detection coil that is not one of the N upper rotation detection coils and is positioned closer to the central axis than the upper rotation detection coil. The at least one upper axial detection coil and the disruptor element are characterized such that the at least one upper axial detection coil has an internal coil area smaller than the disruptor element, and the projection of the disruptor element along the axial direction completely fills the internal coil area of ​​the at least one upper axial detection coil for any position of the disruptor element within the operational range of motion + / -Rz, + / -Rx, and + / -Ry. This ensures that the upper axial detection overlap area (TASOA) does not change with the position of the disruptor element. Similarly, in various such embodiments, the lower axial detector coil arrangement may not be one of the N lower rotation detector coils, but may comprise at least one lower axial detector coil located closer to the central axis than the lower rotation detector coil. The at least one lower axial detector coil and the disruptor element are characterized such that the at least one lower axial detector coil has an internal coil area smaller than the disruptor element, and the projection of the disruptor element along the axial direction completely fills the internal coil area of ​​the at least one lower axial detector coil for any position of the disruptor element within the operational ranges of travel + / -Rz, + / -Rx, and + / -Ry. This ensures that the lower axial detector overlap area BASOA does not change with the position of the disruptor element. It will be appreciated that the particular embodiment of the stylus position detector 511′ shown in FIG. 5 , in which the upper axial detector coil arrangement TASCC and the lower axial detector coil arrangement BASCC each comprise a single detector coil, fits this description.It will be understood that various configurations of the upper and lower axial detection coil arrangements TASCC and BASCC can be used, and the particular configuration shown in Figure 5 is exemplary only and not limiting. Various alternative configurations are described with reference to other figures below.

[0053] In accordance with the principles described and claimed herein, for rotational position detection in a stylus position detection section (e.g., 511′), a receive coil section (e.g., 570) and a disruptor element (e.g., 551) are generally configured to provide N complementary pairs of rotational detection coils CPi (e.g., CP1-CP4, N=4) comprising an upper rotational detection coil TRSCi and a lower rotational detection coil BRSCi, respectively, where for any complementary pair CPi for any disruptor element displacement increment within the operational travel ranges + / -Rz, + / -Rx, and + / -Ry, the magnitude of the change in overlap area TRSCOAi and BRSCOAi associated with that disruptor element displacement increment is nominally the same for that complementary pair. (It will be appreciated that for a particular scanning probe, its operational travel range will be determined or specified, if necessary to meet this requirement, in combination with its particular stylus position detection unit configuration.) The table CPTable in Figure 5 shows each rotation detection coil TRSCi and BRSCi for each complementary pair CPi in the embodiment shown in Figure 5.

[0054] By adhering to the foregoing principles, the complementary pair CPi shown in FIG. 5 can be used to compensate for or eliminate certain cross-coupling errors and / or simplify the signal processing required to provide accurate rotational position or displacement measurements (e.g., along the X and / or Y directions). In particular, pairs of signal components generated in the complementary pair CPi of rotational detection coils in the embodiment shown in FIG. 5 may be combined or processed in a relationship that provides a resultant signal that is nominally insensitive to changes in "proximity" or gaps between the individual coils of the complementary pair and the disruptor element 551. That is, the resultant signal may be insensitive to the axial (Z) position or displacement ΔZ of the disruptor element 551, and nominally sensitive only to rotational position or displacement (e.g., along the X and / or Y directions), as described in more detail below. 5, it will be appreciated that a displacement of disruptor element 551 with a displacement component ΔY along the Y-axis direction increases (or decreases) the overlap area TRSCOA2 and BRSCOA2 in complementary pair CP2 and decreases (or increases) the overlap area TRSCOA1 and BRSCOA1 in complementary pair CP1. Similarly, a displacement of disruptor element 551 with a displacement component ΔX along the X-axis direction increases (or decreases) the overlap area TRSCOA3 and BRSCOA3 in complementary pair CP3 and decreases (or increases) the overlap area TRSCOA4 and BRSCOA4 in complementary pair CP4.

[0055] As outlined above, during operation, currents induced in the disruptor elements 551 by the varying magnetic fields of the field generating coil arrangements 560 cause opposing magnetic fields. In general, the signal component SIGTRSCi (or SIGBRSCi) generated in any rotational detection coil TRSCi (or BRSCi) decreases as the proximal portion of the disruptor element 551 approaches that rotational detection coil along the axial direction or increases its overlap area TRSCOAi (or BRSCOAi) with the rotational detection coil.

[0056] For complementary pairs CP1-CP4 shown in FIG. 5 (the coils of complementary pair CPi are identical and axially aligned), it can be seen that in the illustrated undeflected position UNDF, the signal components of each complementary pair (e.g., SIGTRSC1 and SIGBRSC1) are approximately balanced. In accordance with the principles outlined above, for small displacements ΔZ of the portion of disruptor element 551 proximate to a complementary pair (e.g., CP1), such as would be expected during operation, the net signal components (e.g., SIGTRSC1 and SIGBRSC1) can vary approximately linearly and inversely relative to one another. Thus, the sum of such signals of complementary pair CPi may be nominally insensitive to ΔZ associated with the proximate portion of disruptor element 551. 5, the edges of the disruptor elements 551 can be parallel to the X and Y directions such that within the operational travel ranges + / -Rx and + / -Ry, displacement components in the Y direction do not alter the rotating coil detection overlap areas TRSCOA3, BRSCOA3, and / or TRSCOA4 and BRSCOA4, and displacement components in the X direction do not alter the rotating coil detection overlap areas TRSCOA2, BRSCOA2, and / or TRSCOA1 and BRSCOA1. Thus, in one embodiment, the rotational displacement or position component ΔX along the X direction, ideally regardless of ΔZ and / or ΔY, can be indicated by or correspond to the following signal relationship: ΔX = function [(SIGTRSC3+SIGBRSC3)-(SIGTRSC4+SIGBRSC4)]÷ [(SIGTRSC3+SIGBRSC3)+(SIGTRSC4+SIGBRSC4)] (Formula 6)

[0057] Similarly, in one embodiment, the rotational displacement or position component ΔY along the Y direction, ideally regardless of ΔZ and / or ΔX, can be represented by or correspond to the following signal relationship: ΔY = function [(SIGTRSC2+SIGBRSC2)-(SIGTRSC1+SIGBRSC1)]÷ [(SIGTRSC2+SIGBRSC2)+(SIGTRSC1+SIGBRSC1)] (Formula 7)

[0058] These signal relationships are by way of example only and are not limiting, and in various embodiments, these signal relationships are adjusted or compensated for, as needed, by additional calibration or signal processing operations that include operations to reduce the effects of geometric and / or signal cross-coupling between various displacement directions or signal components.

[0059] In some particularly advantageous embodiments, the receive coil section (e.g., 570) and disruptor element (e.g., 551) are configured such that, for a displacement increment of any complementary pair CPi and any disruptor element within the operational ranges of travel + / -Rz, + / -Rx, and + / -Ry, both the magnitude and sign of the change in overlap region TRSCOAi and BRSCOAi associated with that disruptor element displacement increment are the same for that complementary pair. In some such embodiments, the receive coil section is configured such that each complementary pair CPi includes an upper rotation detection coil TRSCi and a lower rotation detection coil BRSCi that are characterized by nominally matching shapes of their internal regions when projected along the axial direction. It will be understood that the particular embodiment of the stylus position detection section 511′ shown in FIG. 5 fits this description. However, it will be understood that the particular configuration shown in FIG. 5 is illustrative only and not limiting, and that various configurations of complementary pairs may be used. Various alternative configurations are described below with reference to the other figures.

[0060] In some particularly advantageous embodiments, the receive coil section (e.g., 570) and disruptor element (e.g., 551) are configured such that the disruptor element has at least N straight sides, and for any respective complementary pair CPi, each of the disruptor element's straight sides intersects both the upper rotation detection coil TRSCi and the lower rotation detection coil BRSCi of that respective complementary pair. In some such embodiments, N=4, and the at least N straight sides comprise four sides arranged parallel to the sides of a rectangle or square. It will be appreciated that the particular embodiment of the stylus position detection section 511′ shown in FIG. 5 fits this description. However, it will be understood that various combinations of complementary pair configurations and disruptor element edge configurations can be used, and the particular configuration combination shown in FIG. 5 is merely exemplary and not limiting. Various alternative configuration combinations are described with reference to other figures below.

[0061] FIG. 6 is a partial, schematic isometric view of certain components of the stylus position detection unit 511′ shown in FIG. 5 , including connections CONN shown generally in a block diagram of one exemplary embodiment of a signal processing and control circuit 680 according to the principles disclosed herein. As shown in FIG. 6 , the signal processing and control circuit 680 is operatively connected to the various coils of the stylus position detection unit 511′. In the embodiment shown in FIG. 6 , the signal processing and control circuit 680 comprises a digital controller / processor 681 that can manage or exchange operations for various timing and signal connections between its various interconnected components. The digital controller / processor 681 comprises a drive signal generator 682, an amplifier / switching unit 683, a sample and hold unit 684, a multiplexing unit 685, and an A / D conversion unit 686. The digital controller / processor 681 can also perform various digital signal processing operations to determine the output signals APSOut and RPSOut, as outlined above with reference to FIG. 2 and further described below. The design and operation of signal processing and control circuitry 680 can generally be appreciated and understood by those skilled in the art according to known principles. For example, in one embodiment, the various components of signal processing and control circuitry 680 can be designed and operated similarly to corresponding components disclosed in U.S. Patent No. 5,841,274, the entire contents of which are incorporated herein by reference. Accordingly, the operation of the illustrated signal processing and control circuitry 680 will only be briefly described herein.

[0062] During operation, the drive signal generator 682 operates to provide a varying coil drive signal Dsig (e.g., pulses) to the field-generating coil arrangement 560. In response to the coil drive signal, the field-generating coil arrangement 560 generates a varying magnetic flux generally along the axial direction of the disruptor movement volume MV. In the illustrated configuration, the upper field-generating coil 561T and the lower field-generating coil 561B are configured to provide a mutually constructive varying magnetic flux. The amplifier / switching section 683 is configured to input signal components RSIGs and ASIGs from the receive coil section 570. The receive coil section 570 comprises respective signal components (e.g., the previously outlined signal components SIGTASCC, SIGBASCC, SIGTRSC1-SIGTRSC4, and SIGBRSC1-SIGBRSC4) provided by respective rotational and axial detection coils disposed on the upper and lower coil substrates. In some embodiments, amplifier / switching unit 683 may comprise switching circuitry that combines various analog signals to provide various desired sum or difference signals (e.g., via appropriate serial or parallel connections, etc.), e.g., as defined by the relationships shown in Equations 5-7, etc. However, in other embodiments, amplifier / switching unit 683 may perform only amplification and signal conditioning operations (and possibly signal inversion operations), with all signal combining operations being performed by other circuit portions.

[0063] The sample and hold unit 684 receives the various analog signals from the amplifier / switching unit 683 and performs sample and hold operations according to known principles, e.g., to simultaneously sample and hold all respective signal components arising from the various respective detection coils of the receive coil unit 570. In one embodiment, the multiplexing unit 685 can couple the various signals to the A / D converter unit 686 serially and / or in combinations related to various desired signal relationships (e.g., as defined by the relationships shown in Equations 5-7, etc.). The A / D converter unit 686 outputs corresponding digital signal values ​​to the digital controller / processor 681. The digital controller / processor 681 then processes and / or combines the digital signal values ​​to determine and output output signals APSOut and RPSOut according to various desired relationships (e.g., as defined by the relationships shown in Equations 5-7, etc.). The output signals APSOut and RPSOut indicate at least one axial and rotational position of the disruptor element 551 or the stylus 506 relative to the frame or housing of the scanning probe. In some embodiments, the digital controller / processor 681 may be configured so that the output signals APSOut and RPSOut directly indicate the three-dimensional position of the stylus 506 or its contact portion 548 relative to the frame of the scanning probe. In other embodiments, the digital controller / processor 681 may be configured to output signals that indirectly indicate the three-dimensional position of the stylus 506 or its contact portion 548 relative to the frame of the scanning probe. The host system (e.g., a CMM) then inputs such signals and performs additional processing to further combine or refine such signals and determine the three-dimensional position of the stylus 506 or its contact portion 548 relative to all coordinate systems used in the scanning probe and / or CMM measurements.

[0064] In embodiments of a stylus position detection section (e.g., 511′) according to the various principles disclosed and claimed herein, it will be appreciated that the signal components provided by the various receive coils of the receive coil section (e.g., 570) are particularly advantageous with respect to removing or correcting certain signal errors and / or signal cross-coupling errors, while using relatively fast and simple signal processing to provide a robust and highly accurate three-dimensional position indication.

[0065] With regard to the use of relatively fast and simple signal processing to provide a robust and highly accurate three-dimensional position indication, one consideration is the linearity of the position or displacement signal components (or the linearity of certain combined signals, such as the Z signal relationship shown in Equation 5). It should be understood that signals or signal relationships that vary with displacement due to significant third- and / or fifth-order signal variation contributions will generally require more complex signal processing and / or correction and / or calibration to provide an accurate displacement or position indication. The inventors have discovered that certain desirable configurations tend to suppress the contributions of higher-order signal variations in the axial signal components A and / or combinations thereof. As one way of describing these desirable configurations, the detector coils of the upper and lower axial detector coil arrangements TASCC and BASCC may be considered to define an "axial detector coil inscribed cylinder," defined to be concentric with the central axis CA and have the minimum necessary radius such that the upper and lower axial detector coils (e.g., the detector coils of the upper and lower axial detector coil arrangements TASCC and BASCC shown in FIG. 5) can fit inside them (i.e., the axial detector coil inscribed cylinder may be defined to be concentric with the central axis CA and have a radius that is the largest radius that can be inscribed within the edges of the upper and lower axial detector coils). A "disruptor inscribed cylinder" may be defined to be concentric with the central axis CA and have a radius that is the largest radius that can be inscribed within the edges of a disruptor element (e.g., disruptor element 551). In various embodiments, it is desirable (but not required) that the radius of the disruptor inscribed cylinder be at least 1.1 times the radius of the axial detector coil area inscribed cylinder. In some embodiments, it is desirable (but not essential) for the radius of the disruptor inscribed cylinder to be at least 1.2 or at least 1.5 times the radius of the axial detection coil region inscribed cylinder.

[0066] 7A-7E illustrate "planar" views (viewed along the axial or Z direction) depicting embodiments of "four complementary pairs" of stylus position detection unit components, respectively, including receive coil sections 770A-770E and disruptor elements 751A-751E, in accordance with the principles disclosed herein. The illustrated components are usable in various embodiments of stylus position detection units according to the principles disclosed herein. While field-generating coils are not shown in FIGS. 7A-7E, it will be understood that they are provided in accordance with the principles previously disclosed. The various components illustrated in FIGS. 7A-7E are the same or similar to like-numbered components in the previously described stylus position detection units 311, 411, 511, and / or 511′ and can generally be understood by analogy thereto. Accordingly, only certain unique or significant characteristics of the "four complementary pairs" embodiments included in FIGS. 7A-7E are described below.

[0067] Figure 7A illustrates, and can be understood by analogy with, an embodiment of a receive coil section 770A and a disruptor element 751A similar to those described above with reference to stylus position detection section 511'. In addition to illustrating circular upper and lower axial detection coil arrangements TASCC and BASCC similar to those described above with reference to stylus position detection section 511', Figure 7A also illustrates alternative square upper and lower axial detection coil arrangements TASCC' and BASCC', shown in dashed lines. More generally, it will be understood that any desired shape can be used for the upper and lower axial detection coil arrangements, so long as they are configured to provide the desired operation in accordance with the various principles disclosed and / or claimed herein.

[0068] Note that the shape of disruptor element 751A includes "trimmed corners" for compactness. To realize the principles previously disclosed herein, the magnitude of change in overlap areas TRSCOAi and BRSCOAi associated with a disruptor displacement increment is nominally the same for any of the illustrated complementary pairs, and therefore, the ranges of operational travel + / -Rx and + / -Ry along the orthogonal X and Y directions can be defined or specified to not exceed the straight edge portions that traverse each complementary pair to satisfy this principle.

[0069] 7B illustrates an embodiment of a receive coil section 770B and disruptor element 751B similar to that described above with reference to FIG. 7A, except that the complementary pair CP1-CP4 of receive coil section 770B includes a larger rotational detection coil that overlaps the detection coils of the upper and lower axial detection coil arrangements TASCC and BASCC. Note that including such a large rotational detection coil in the complementary pair CP1-CP4 is not prohibited in accordance with various principles disclosed herein. To fabricate such a configuration, the rotational and axial detection coils can be fabricated, for example, on respective layers of a multilayer printed circuit board.

[0070] 7C illustrates an embodiment of a receive coil section 770C and disruptor element 751C similar to that described above with reference to FIG. 7B, except that the upper and lower axial detector coil arrangements TASCC and BASCC are not provided by axial detector coils separate from the various rotating detector coils TRSCi and BRSCi. Instead, it will be appreciated that the upper axial detector coil arrangement TASCC comprises a combination of N (N=4) upper rotating detector coils TRSC1-TRSC4, and the upper axial detector overlap area TASOA comprises the sum of the individual overlap areas TRSCOAi associated with the N upper rotating detector coils. It will be observed that, due to the similar shapes of the N upper rotating detector coils TRSC1-TRSC4 and the two parallel pairs of disruptor elements overlapping them, all overlap area lost in overlap area TRSCOA1 due to a displacement increment of the disruptor element 751C is gained in overlap area TRSCOA2, and vice versa. Similarly, all overlap area lost in overlap area TRSCOA3 is gained in overlap area TRSCOA4, and vice versa. Thus, the sum of overlap areas TRSCOAi does not change with or depend on the position of the disruptor element 751C within the operational ranges of travel + / -Rz, + / -Rx, and + / -Ry, even though its constituent individual overlap areas TRSCOAi change depending on the position of the disruptor element 751C. Similarly, the lower axial detection coil configuration BASCC comprises a combination of N (N=4) lower rotation detection coils BRSC1-BRSC4, and the lower axial detection overlap area BASOA comprises the sum of the individual overlap areas BRSCOAi associated with the N lower rotation detection coils. The sum of the overlap areas BRSCOAi also does not vary with or depend on the position of the disruptor element 751C within the operating ranges of travel + / -Rz, + / -Rx, and + / -Ry, even though the constituent individual overlap areas BRSCOAi may vary depending on the position of the disruptor element 751C.7C provides a configuration in accordance with the general principles disclosed herein, in which receive coil section 770C and disruptor element 751C are configured to provide upper and lower axial-sensing overlap areas TASOA and BASOA, respectively, the amounts of overlap TASOA and BASOA not varying with or dependent on the position of the disruptor element within its operational ranges of motion + / -Rz, + / -Rx, and + / -Ry.

[0071] 7D shows an embodiment of a receive coil section 770D and disruptor element 751D that functions in a manner similar to that described above with reference to FIG. 7C, except that the axial detection coil arrangements TASCC and BASCC are not provided by axial detection coils that are separate from the various rotational detection coils TRSCi and BRSCi. Instead, the upper and lower axial detection coil arrangements TASCC and BASCC comprise respective combinations of N (N=4) upper and lower rotational detection coils TRSC1-TRSC4 and BRSC1-BRSC4. The upper axial detection overlap area TASOA comprises the sum of the individual overlap areas TRSCOAi associated with the N upper rotational detection coils, and the lower axial detection overlap area BASOA comprises the sum of the individual overlap areas BRSCOAi associated with the N lower rotational detection coils. Similar to the configuration shown in FIG. 7C , the sum of overlap areas TRSCOAi does not vary with or is independent of the position of the disruptor element 751D within the operational range of motion + / −Rz, + / −Rx, and + / −Ry, even though successive individual overlap areas TRSCOAi vary depending on the position of the disruptor element 751D. And the sum of overlap areas BRSCOAi does not vary with or is independent of the position of the disruptor element 751D within the operational range of motion + / −Rz, + / −Rx, and + / −Ry, even though successive individual overlap areas BRSCOAi vary depending on the position of the disruptor element 751D. Thus, despite its differences from the previously described configurations, the embodiment shown in FIG. 7D provides a configuration according to the general principles disclosed herein. The receive coil section 770D and disruptor elements 751D are configured to provide an upper axial-sensing overlap area TASOA and a lower axial-sensing overlap area BASOA. The respective amounts of overlap areas TASOA and BASOA do not vary with or depend on the position of the disruptor element within the operating travel ranges + / -Rz, + / -Rx, and + / -Ry.It will be understood that due to the illustrated shape of disruptor element 751D, to satisfy the principles disclosed earlier herein, the magnitude of change in overlap areas TRSCOAi and BRSCOAi associated with a disruptor displacement increment is nominally the same for any of the illustrated complementary pairs, and the ranges of operational movement + / -Rx and + / -Ry along the orthogonal X and Y directions are defined or specified such that none of the corners of disruptor element 751D move to their illustrated positions to such an extent that they cross the boundaries of the detection coils of any of the complementary pairs CP1-CP4.

[0072] FIG. 7E illustrates an embodiment of a receive coil section 770E and a disruptor element 751E similar to that described above with reference to FIG. 7A (or the stylus position detection section 511′), except that the upper and lower rotational detection coils of each complementary pair CPi are rotated relative to each other about the central axis by an angle 2*NAA. Note that NAA is the “non-alignment angle.” However, this embodiment becomes increasingly disadvantageous compared to the previously described configuration (in which the upper and lower rotational detection coils of each complementary pair CPi are aligned along the axial direction) as the non-alignment angle NAA increases. The reason for this disadvantage is that, because their overlapping regions with the disruptor element 751E are not “co-located,” the sum of the operating gaps between the disruptor element 751E and the upper and lower rotational detection coils of each complementary pair CPi (e.g., operating gap OG shown in FIG. 3) is not necessarily constant for all displacements of the disruptor element 751E. Therefore, their sum may not ideally be independent of the axial displacement ΔZ, as described above with reference to Equation 6. The configuration outlined above and shown in FIG. 7 is not prohibited in accordance with the various principles disclosed herein. It will be appreciated that such a configuration can still satisfy the most basic principles disclosed and claimed herein and provide signal components that at least partially retain the various advantages outlined above compared to known inductive sensor configurations. One way to describe the configuration shown in FIG. 7E is that the receive coil section 770E is configured so that each complementary pair CPi includes an upper rotating detector coil TRSCi and a lower rotating detector coil BRSCi whose internal region shapes are nominally identical when rotated about a central axis (e.g., by an angle 2*NAA) so that the shape of one of the complementary pair matches the angular position of the other about the central axis and projected along the axial direction (i.e., the shapes of the internal regions of the upper rotating detector coil TRSCi and the lower rotating detector coil BRSCi nominally match when rotated about the central axis so that the shape of one of the complementary pair matches at the angular position of the other about the central axis).In various embodiments, the receive coil section 770E and the disruptor element 751E may be configured such that the disruptor element 751E has at least N straight sides (e.g., N=4), and for any respective complementary pair CPi (e.g., CP1-CP4), each of the straight sides of the disruptor element 751E traverses both the upper rotation detection coil TRSCi and the lower rotation detection coil BRSCi of that respective complementary pair CPi. In such an embodiment where N=4, the at least N straight sides of the disruptor element 751E comprise four sides arranged parallel to the sides of a rectangle or square.

[0073] 8A-8F show "plan view" views (along the axial or Z direction) illustrating respective "three (or six) complementary pairs" of stylus position detection unit components comprising receive coil sections 870A-870F and disruptor elements 851A-851F, respectively, in accordance with the principles disclosed herein. The illustrated components are usable in various embodiments of stylus position detection units in accordance with the principles disclosed herein. While field-generating coils are not shown in FIGS. 8A-8F, it will be understood that they are provided in accordance with the principles previously disclosed. The various components shown in the "three (or six) complementary pairs" configurations illustrated in some of FIGS. 8A-8F are similar to, and can generally be understood by analogy with, corresponding components shown in the corresponding "four complementary pairs" configurations described above with reference to FIGS. 7A-7E. Accordingly, only certain unique or significant characteristics of the "three complementary pairs" embodiments included in FIGS. 8A-8F will be described below.

[0074] Figures 8A-8C are "three complementary pair" analogs of the "four complementary pair" constructs shown in corresponding Figures 7A-7C, and can generally be understood by analogy with their corresponding construct descriptions (e.g., Figure 8A to its corresponding Figure 7A, etc.), based on the additional description below.

[0075] In contrast to the four previously described complementary pairs oriented 90 degrees from each other (e.g., as shown in FIG. 7A), the use of three complementary pairs oriented 120 degrees from each other can be understood by considering that any displacement increment or position of a disruptor element (e.g., 851A) is readily characterized by the displacement or position vector components or coordinates oriented along each of the vector component directions VC1, VC2, and VC3 shown in FIGS. 8A-8F, as opposed to the displacement or position vector components or coordinates oriented along the X-axis and Y-axis directions shown in the various figures herein. Methods for converting vector components from one coordinate system to another are well known and need not be described in detail here. Based on this, it will be appreciated that the complementary pairs CPi shown in FIGS. 8A-8C are constructed according to the same principles outlined in the preceding description of complementary pairs, with their respective overlapping regions indicating the displacement or position of the disruptor element along their corresponding vector component directions VC1, VC2, and VC3. For example, the representative overlap regions TRSCOA1 and BRSCOA1 shown in Figure 8A result in associated signal components SIGTRSC1 and SIGBRSC1 according to the principles previously described that indicate the displacement or position of the disruptor elements along the corresponding vector component direction VC1, etc. In the embodiments shown in Figures 8A, 8C, and 8E, in one embodiment, the rotational displacement or position component ΔVC1 along the VC1 direction can be indicated by or correspond to the following signal relationship, which is nominally independent of ΔZ according to the principles previously outlined for comparable complementary pairs: ΔVC1 = function [(SIGTRSC1+SIGBRSC1)-(SIGTRSC1 UNDF +SIGBRSC1 UNDF ] (Formula 8)

[0076] where SIGTRSC1 UNDF and SIGBRSC1 UNDF is the reference signal value resulting from the overlap region TRSCOA1 and BRSCOA1 corresponding to the undeflected position UNDF of the disruptor element (such as 851A).

[0077] Similarly, the rotational displacement or position component ΔVC2 along the VC2 direction and the rotational displacement or position component ΔVC3 along the ΔVC3 direction may be represented by or correspond to the following signal relationships: ΔVC2 = function [(SIGTRSC2 + SIGBRSC2) - (SIGTRSC2 UNDF +SIGBRSC2 UNDF ] (Formula 9) ΔVC3 = function [(SIGTRSC3 + SIGBRSC3) - (SIGTRSC3 UNDF +SIGBRSC3 UNDF ] (Formula 10)

[0078] It will be understood that the axial detection coil configurations TASCC and BASCC shown in Figures 8A-8C are substantially the same as those previously described herein with reference to corresponding configurations and can be determined according to the same types of signal components and signal relationships. The signal relationships outlined above are exemplary only and are not limiting. In various embodiments, these signal relationships may be adjusted or compensated for by additional calibration or signal processing operations, as needed, including operations to reduce the effects of geometric and / or signal cross-coupling between various displacement directions or signal components.

[0079] FIG. 8D illustrates an embodiment of a receive coil section 870D and disruptor element 851D similar to that described above with reference to FIG. 8A, except that additional complementary pairs CP4-CP6 are provided, configured symmetrically across the central axis from complementary pairs CP1-CP3, for a total of six complementary pairs. In particular, CP1 and CP4 face opposite each other along the VC1 direction, CP2 and CP5 face opposite each other along the VC2 direction, and CP3 and CP6 face opposite each other along the VC3 direction. These opposing pairs are similar to the opposing complementary pairs shown along the X and Y axes in FIGS. 7A-7D. Such a configuration is useful for determining the reference signal values ​​(e.g., SIGTRSC1) used in Equations 8-10. UNDF8D , in one embodiment, the rotational displacement or position component ΔVC1 along the VC1 direction may be represented by or correspond to the following signal relationship: ΔVC1 = ΔV / √{square root over (V)} ... ΔVC1 = function [(SIGTRSC1+SIGBRSC1)-(SIGTRSC4+SIGBRSC4)]÷ [(SIGTRSC1+SIGBRSC1)+(SIGTRSC4+SI GBRSC4)] (Equation 11) ΔVC2 = function [(SIGTRSC2+SIGBRSC2)-(SIGTRSC5+SIGBRSC5)]÷ [(SIGTRSC2+SIGBRSC2)+(SIGTRSC5+SI GBRSC5)] (Equation 12) ΔVC3 = function [(SIGTRSC3+SIGBRSC3)-(SIGTRSC6+SIGBRSC6)]÷ [(SIGTRSC3+SIGBRSC3)+(SIGTRSC6+SI GBRSC6)] (Equation 13)

[0080] It will be appreciated that the "three complementary pairs" embodiment shown in Figures 8B and 8C can be similarly adapted to have six complementary pairs and use similar signal processing with similar advantages.

[0081] FIG. 8E illustrates an embodiment of a receive coil section 870E and disruptor element 851E similar to that described above with reference to FIG. 7E and will generally be understood by analogy with that description in conjunction with the preceding description of FIGS. 8A-8C. A simplified restatement of that description is that in FIG. 8E, the upper and lower rotating detector coils of each complementary pair CPi are rotated relative to one another about the central axis by an angle 2*NAA, where NAA is the "misalignment angle." This embodiment becomes increasingly disadvantageous compared to the configuration outlined above (in which the upper and lower rotating detector coils of each complementary pair CPi are axially aligned) as the misalignment angle NAA increases, as described above with reference to FIG. 7E. It is noted here that the sum of the signals from the complementary pairs may not ideally be independent of axial displacement ΔZ, as described above with reference to Equation 6. Nevertheless, such a configuration is not prohibited in accordance with the various principles disclosed herein. It will be appreciated that such an arrangement can provide signal components that still meet the most basic principles disclosed and claimed herein and retain, at least in part, the various advantages outlined above compared to known inductive sensor arrangements.

[0082] 8F illustrates an embodiment of a receive coil section 870F and a disruptor element 851F in which a complementary pair of detector coils CPi has detector coils configured differently from those of the previously described complementary pairs (e.g., shown in FIG. 8A) and is arranged symmetrically about a central axis. Thus, the receive coil section and disruptor element are characterized similarly to the previously described complementary pairs in that the receive coil section and disruptor element are further configured such that for a displacement increment of any complementary pair CPi and any disruptor element within the operational travel ranges + / -Rz, + / -Rx, and + / -Ry, the magnitude of the change in overlap areas TRSCOAi and BRSCOAi associated with the disruptor displacement increment is the same for that complementary pair. Furthermore, in the embodiment shown in FIG. 8F, the receive coil section is configured similarly to several complementary pairs previously described herein, with each complementary pair CPi comprising an upper rotating detection coil TRSCi and a lower rotating detection coil BRSCi that are rotated at an offset angle (e.g., 180 degrees) about the central axis so that the shape of one of them (i.e., the upper rotating detection coil TRSCi and the lower rotating detection coil BRSCi) matches the angular position of the other about the central axis, and characterized so that the shapes of their internal regions nominally match when projected along the axial direction.

[0083] However, in contrast to the previously described complementary pairs, the sign of the change in overlap area TRSCOAi and BRSCOAi relative to a disruptor displacement increment is opposite in the complementary pair shown in FIG. 8F. Such an embodiment may have certain disadvantages compared to embodiments in which the sign of the change in overlap area TRSCOAi and BRSCOAi relative to a disruptor displacement increment is the same for each complementary pair. However, the configuration shown in FIG. 8F is nevertheless not prohibited in accordance with various principles disclosed herein. With appropriate signal processing, such an embodiment can offer certain advantages for use in a scanning probe compared to known inductive sensing configurations. The signal processing may need to be more complex than required in previously disclosed embodiments herein (e.g., using more complex signal component relationships to represent various displacement or position vector components) to correct for or compensate for various cross-coupling effects, etc. However, for receive coil section 870F, such effects can generally be compensated for based on known geometric and / or signal relationship constraints and the fact that the magnitude of the change in overlap area for a given displacement of disruptor element 851F is the same for each complementary pair of sensing coils. 8F, disruptor element 851F has three pairs of parallel straight sides (e.g., arranged parallel to the sides of a regular hexagon), such that for any respective complementary pair CPi, the first of the pair of parallel straight sides intersects the upper rotating detection coil TRSCi and the second of that pair of parallel straight sides intersects the lower rotating detection coil BRSCi of its respective complementary pair. Based on the known rigid-body translation and rotation characteristics of disruptor element 851F, the respective overlap regions and local operating gaps of each detection coil are provided in receive coil section 870F such that they are constrained by known relationships to one another, and these known relationships can be used in signal processing of the signal components provided by receive coil section 870F to determine accurate displacement vectors.

[0084] It will be appreciated that the variations shown in Figures 7A-7E and 8A-8F retain many or all of the advantages previously discussed in connection with the various principles disclosed and claimed herein, while illustrating the possibility of further rearranging and / or adjusting the configuration and combination of the various components within the stylus position detection unit in accordance with these principles. In general, it should be understood that the various embodiments disclosed herein are for illustrative purposes only and not limiting.

[0085] Figures 9A and 9B show an alternative configuration of a stylus position detector 911. This stylus position detector may be used, for example, as stylus position detector 311 in scanning probe 300 of Figure 2, in place of stylus position detector 411 in the embodiment of Figure 3, in place of stylus position detector 511 in the embodiment of Figure 4, etc. Inductive components are shown in Figure 9B. The stylus position detector 911 uses inductive detection principles and comprises a coil substrate arrangement 990 having a receive coil section 970, a field generating coil arrangement 960 comprising a transmit coil (first field generating coil) 961 as shown, and a disruptor arrangement 950 comprising first and second disruptor elements 951 as shown. The receive coil section 970 may comprise a rotational detector coil section (also referred to as a rotational detector coil) RSC and an axial detector coil arrangement ASCC. Simply put, the moving disruptor element 951 (or, more generally, the disruptor arrangement 950) causes position-dependent variations in the varying magnetic field produced by the field-generating coil arrangement 960. The receive coil section 970 responds to the varying magnetic field caused by the disruptor element 951 and the variations therebetween.

[0086] The coil substrate assembly 990 includes a first substrate portion 992 including N upper rotary detector coil sections (upper rotary detector coils, TRSC1 to TRSC4 as shown, where N=4 in this example) and an upper axial detector coil assembly (TASCC as shown), and a second substrate portion 994 including N lower rotary detector coil sections (lower rotary detector coils, BRSC1 to BRSC4 as shown, where N=4 in this example) and a lower axial detector coil assembly (BASCC as shown). The coil substrate assembly 990 also includes a central substrate portion 996 disposed between the first substrate portion 992 and the second substrate portion 994. The central substrate portion 996 includes at least a first field-generating coil assembly 960 (including a transmit coil 961 as shown). The coil substrate arrangement 990 is mounted in fixed relationship to the frame of the scanning probe (see scanning probe 300 in FIG. 2 and frame 408 in FIG. 4), with a second substrate portion 994 of the coil substrate arrangement 990 closer to the stylus suspension 307 / 407 (see FIGS. 2 and 3). The first substrate portion 992, second substrate portion 994 and central substrate portion 996 of the coil substrate arrangement 990 are nominally parallel to one another and nominally perpendicular to the central axis CA (see FIG. 3) of the scanning probe 300 (see FIG. 2). The coil substrate arrangement 990 may comprise, for example, a double-sided board or printed circuit board having a coil fabricated as a printed conductor on a layer of the board or printed circuit board, a free-standing coil fixed to a board or printed circuit board, etc., and / or various combinations thereof.

[0087] In various embodiments, the disruptor elements 951 of the disruptor arrangement 950 each comprise at least one of a conductive plate or a conductive loop that provides a disruptor area, and the disruptor elements 951 are arranged along a central axis CA (see FIG. 3) in a disruptor movement volume that extends on opposite sides of the coil substrate arrangement 990. The disruptor element 951 comprises an upper portion of the moving member 912 (e.g., similar to the moving member 412 of FIG. 3) and is coupled to the stylus suspension 307 / 407 (see FIGS. 2 and 3) in a fixed relationship relative to each other by a coupling arrangement 953. The disruptor element 951 moves within the disruptor movement volume relative to an undeflected position in response to deflection of the stylus suspension 307 / 407 (see Figures 2 and 3), with the disruptor element moving through an axial range of motion + / -Rz in response to axial motion and respective orthogonal X and Y directions orthogonal to the axial direction, + / -Rx and + / -Ry. The projection of the coil area of ​​the first field-generating coil 961 along the axial direction encompasses conductive plates or loops that provide the disruptor and coil areas of all rotational and axial detection coils disposed on the coil substrate arrangement 990. The field-generating coil arrangement 960 generates a varying magnetic flux generally along the axial direction within the disruptor movement volume in response to a coil drive signal.

[0088] Figure 10 is a partial schematic isometric view of an embodiment of a stylus position detector 1011 similar to the stylus position detector 911 shown in Figures 9A and 9B, highlighting certain features in accordance with principles disclosed herein. It will be understood that, in general, the stylus position detector 1011 includes certain components similar to those of the stylus position detectors 311, 411, 511, and 911 of Figures 2, 3, 4, 9A, and 9B, and operates similarly except as noted below. The stylus position detector 1011 configuration may be used, for example, as the stylus position detector 311 in the scanning probe 300 of Figure 2, in place of the stylus position detector 411 in the embodiment of Figure 3, in place of the stylus position detector 511 in the embodiment of Figure 4, in place of the stylus position detector 911 in the embodiment of Figures 9A and 9B, etc.

[0089] 10, the stylus position detection portion 1011 includes a coil substrate assembly 1090 and a disruptor assembly 1050. The coil substrate assembly 1090 includes a field-generating coil substrate portion 1060 disposed between an upper receive coil substrate portion 1070T and a lower receive coil substrate portion 1070B, comprising upper and lower receive coil substrate portions 1070T, 1070B. In various embodiments, the upper and lower receive coil substrate portions 1070T, 1070B are also referred to as first and second substrate portions 1070T, 1070B, and the field-generating coil substrate portion 1060 is also referred to as a central substrate portion 1060. The disruptor assembly 1050 includes disruptor elements 1051T, 1051B or a scale. In various embodiments, the disruptor elements 1051T, 1051B are also referred to as first and second disruptor elements 1051T, 1051B.

[0090] In various embodiments, the disruptor elements 1051T, 1051B (or more generally the disruptor structure 1050) may each comprise at least one of a conductive plate or loop that provides a disruptor area (e.g., an interior area thereof), or parallel conductive plates or loops (e.g., as provided on two sides of a printed circuit board patterned by printed circuit board manufacturing techniques), or any other desired operating structure. As shown in FIG. 10 , the disruptor elements 1051T and 1051B each comprise a conductive plate. The disruptor elements 1051T and 1051B are positioned along a central axis CA of the disruptor moving volume MV that extends on opposite sides of the coil substrate structure 1090 and are coupled to the stylus suspension 1007 by a coupling structure (e.g., comprising at least an upper portion of the moving member 1012 similar to the moving member 412 of FIG. 3 ). For purposes of explanation, the disruptor elements 1051T, 1051B move relative to an undeflected position shown in Figure 10 (e.g., similar to the undeflected position UNDF of Figure 3) in response to deflection of the stylus suspension 1007 and / or stylus 1006 and / or moving member 1012 (which may, for example, be similar to or identical to the stylus suspension 407, stylus 406 and moving member 412 of Figure 3). The disruptor elements 1051T, 1051B can be described as moving along the axial direction in displacement increments ΔZ over an operational range of travel + / -Rz in response to axial movement, and along orthogonal X and Y directions orthogonal to the axial direction (Z direction) in displacement increments ΔX and ΔY, respectively, over respective operational ranges of travel + / -Rx and + / -Ry in response to rotational movement.

[0091] The upper receiver coil substrate section 1070T includes N upper rotating detector coils TRSC (e.g., TRSC1 to TRSC4 as shown, N=4) and an upper axial detector coil arrangement TASCC (e.g., comprising a single illustrated individual coil in this embodiment), and the lower receiver coil substrate section 1070B includes N lower rotating detector coils BRSC (e.g., BRSC1 to BRSC4 as shown, N=4) and a lower axial detector coil arrangement BASCC (e.g., comprising a single illustrated individual coil in this embodiment).

[0092] The coil substrate arrangement 1090 is mounted in fixed relation to the frame of the scanning probe (e.g., frame 408 of FIG. 4 ) at the lower receive coil substrate portion 1070B, which is closer to the stylus 1006 and / or stylus suspension 1007. With respect to the various detector coils shown in FIG. 10 , it will be understood that all coils comprise at least one winding or conductor having first and second connection ends (e.g., as shown in FIG. 6 ) configured to operate with one or more turns inductively coupled. As shown, the upper and lower axial detector coil arrangements TASCC and BASCC, and the upper and lower rotational detector coil arrangements TRSC and BRSC, are spaced nominally symmetrically with respect to the location of the disruptor arrangement 1050 and corresponding disruptor elements 1051T, 1051B. Other configurations are possible (e.g., in some embodiments, the rotational detector coil arrangements TRSC and BRSC may not be nominally centered with respect to the disruptor arrangement 1050).

[0093] The field-generating coil substrate section 1060 generally comprises at least a first field-generating coil 1061 and is disposed between the upper receive coil substrate section 1070T and the lower receive coil substrate section 1070B. As shown in Figure 10, the at least first field-generating coil comprises a single field-generating coil 1061 having an area larger than the areas of the disruptor elements 1051T, 1051B. The upper receive coil substrate section 1070T, the field-generating coil substrate section 1060, and the lower receive coil substrate section 1070B are nominally planar, nominally parallel to one another, and nominally perpendicular to the central axis CA.

[0094] In the embodiments illustrated in FIGS. 3, 4, and 5, the disruptor elements are positioned inside the field-generating coil elements (e.g., disruptor element 551 in FIG. 4 fits inside field-generating coil 561), and the area of ​​the disruptor elements is smaller than the area of ​​the field-generating coil elements. In the illustrated embodiments of FIGS. 9A, 9B, and 10, the disruptor elements are positioned parallel to the field-generating coil elements (e.g., disruptor elements 1051T, 1051B are positioned above and below field-generating coil 1061). The configurations of FIGS. 9A, 9B, and 10 provide increased flexibility regarding the relative sizes of the disruptor elements and field-generating coil elements. Additionally, utilizing a single printed circuit board (e.g., where the first substrate portion, second substrate portion, and center substrate portion may comprise portions of a single multilayer printed circuit board) can reduce cost and complexity relative to configurations utilizing multiple printed circuit boards.

[0095] Figure 11 is a partial schematic isometric view of an alternative embodiment of a stylus position detector 1111 similar to the stylus position detector 1011 shown in Figure 10, highlighting certain features in accordance with principles disclosed herein. It will be understood that, in general, the stylus position detector 1111 comprises certain components similar to those of the stylus position detector 1011 of Figure 10 and operates similarly, except as otherwise described below. The stylus position detector 1111 configuration may be used, for example, as stylus position detector 311 in scanning probe 300 of Figure 2, in place of stylus position detector 411 in the embodiment of Figure 3, in place of stylus position detector 511 in the embodiment of Figure 4, in place of stylus position detector 911 in the embodiment of Figures 9A and 9B, in place of stylus position detector 1011 in the embodiment of Figure 10, etc.

[0096] 11 , the stylus position detection portion 1111 includes a coil substrate assembly 1190 and a disruptor assembly 1150. The coil substrate assembly 1190 includes a field-generating coil substrate section 1160 disposed between an upper receive coil substrate section 1170T and a lower receive coil substrate section 1170B, comprising upper and lower receive coil substrate sections 1170T, 1170B. In various embodiments, the upper and lower receive coil substrate sections 1170T, 1170B are also referred to as first and second substrate sections 1170T, 1170B, and the field-generating coil substrate section 1160 is also referred to as a central substrate section 1160. The disruptor assembly 1150 includes disruptor elements 1151T, 1151B or scales. In various embodiments, the disruptor elements 1151T, 1151B are referred to as first and second disruptor elements 1151T, 1151B. The illustrated upper and lower receive coil substrate sections 1170T, 1170B are generally similar to the corresponding upper and lower receive coil substrate sections 1070T, 1070B of Figure 10 (details of the conductive vias and pads are shown in Figure 11).

[0097] In various embodiments, the disruptor elements 1151T, 1151B (or, more generally, the disruptor structures 1150) can each comprise at least one of a conductive plate or a conductive loop, or parallel conductive plates or loops (e.g., as provided on two sides of a printed circuit board patterned by printed circuit board manufacturing techniques), or any other desired operating structure that provides a disruptor area (e.g., an interior area thereof). In various embodiments, the structures comprising conductive loops can comprise at least one of concentric loops, spiral patterns, etc. As shown in FIG. 11, the disruptor elements 1151T and 1151B each comprise a plurality of concentric conductive loops 1153 instead of the conductive plates used in the embodiment illustrated in FIG. 10. The disruptor elements 1151T and 1151B extend on opposite sides of the coil substrate arrangement 1190 and are positioned along a central axis CA of the disruptor movement volume MV which is coupled to the stylus suspension in a manner similar to that described above with reference to Figure 10 (see stylus suspension 1007 in Figure 10).

[0098] The field-generating coil substrate section 1160 typically includes at least a first field-generating coil. As shown, the field-generating coil substrate section 1160 includes an upper field-generating coil section 1161T and a lower field-generating coil section 1161B, and is disposed between an upper receive coil substrate section 1170T and a lower receive coil substrate section 1170B. The upper receive coil substrate section 1170T, the field-generating coil substrate section 1160, and the lower receive coil substrate section 1170B are nominally planar, nominally parallel to one another, and nominally perpendicular to the central axis CA. In the embodiment of FIG. 11, the field-generating coil substrate section 1160 includes a two-turn multi-turn field-generating coil. and two corresponding field generating coil sections 1161T and 1161B connected by a via and positioned approximately equidistant from the mid-plane of the disruptor movement volume MV along the central axis and nominally perpendicular to the central axis in the plane (i.e., the field generating coil arrangement comprises a multi-turn field generating coil with at least two turns and two corresponding field generating coil sections 1161T and 1161B positioned approximately equidistant from the mid-plane of the disruptor movement volume MV along the central axis CA and nominally perpendicular to the central axis CA in the plane).

[0099] As shown in FIG. 11 , the upper and lower field generating coil sections 1161T and 1161B have areas smaller than the areas of the disruptor elements 1151T, 1151B. Using field generating coils having areas smaller than the areas of the disruptor elements facilitates reducing the sensitivity of the stylus position detection section 1111 to the size of the disruptor elements or scale. The use of conductive loops (e.g., concentric loops, spiral patterns, etc.) in the disruptor elements, instead of conductive plates or single conductive loops, also facilitates reducing the sensitivity of the stylus position detection section 1111 to the size of the disruptor elements or scale while maintaining good X and Y position signal strength. Reducing the sensitivity of the stylus section to the size of the disruptor elements or scale can improve measurement accuracy and reduce processing costs associated with producing results in a desired output format.

[0100] In some embodiments, due to the proximity of the receive coils (e.g., rotational detection coils BRSC1-BRSC4, TRSC1-TRSC4) to the transmitters (e.g., field generating coil sections 1161T, 1161B), unconnected vias / pads may be added to balance offsets otherwise produced by connecting traces (such as transmitter and receiver leads) or other components. As an illustrative example, in the embodiment of FIG. 11, certain connecting vias / pads / leads (e.g., as connected to electronic circuits or configurations and / or portions thereof) are shown in the rotational detection coil BRSC3 / TRSC3 (e.g., for connecting traces) that do not have symmetrically connected counterparts (e.g., symmetric about a central axis) in the symmetric rotational detection coil BRSC4 / TRSC4 (e.g., five such vias, as well as top and bottom transmit leads, are shown in the rotational detection coil BRSC3 / TRSC3 of the example configuration of FIG. 11, including three vias for connections for axial detection coil configurations TASCC, BASCC, and normalization coil R N (These include vias for connecting the field-generating coil sections 1161T, 1161B, vias for connecting the field-generating coil sections 1161T, 1161B, and upper and lower transmit leads for the field-generating coil sections 1161T, 1161B. In some embodiments, such traces / vias / pads / leads can reduce magnetic fields into the receive coils that, if uncompensated, result in signal offsets. In some embodiments, such offsets can be addressed by mirroring such features (e.g., on opposite sides of the central axis) in a symmetric receive coil with unconnected vias / pads / leads. For example, in one embodiment, unconnected vias / pads / leads can be added in the rotational detection coils BRSC4 / TRSC4, each of which can mirror / symmetrically represent the corresponding connecting vias / pads / leads in the rotational detection coils BRSC3 / TRSC3 (e.g., five unconnected vias and top and bottom pads can be added in the rotational detection coils BRSC4 / TRSC4, each of which can mirror / symmetrically represent the corresponding connecting vias / pads / leads shown in the rotational detection coils BRSC3 / TRSC3).

[0101] As a specific illustrative example of such a concept, in FIG. 11, a normalized coil R N The connection of the part A connecting component (e.g., a via) is shown electrically connected through VIA1C and is shown in the rotational detection coil BRSC3 / TRSC3. In accordance with the principles described above, an unconnected via VIA1D can be included in the rotational detection coil BRSC4 / TRSC4 that mirrors / symmetrically (e.g., mirrors and symmetrically about the central axis of the structure) the corresponding connecting via VIA1C shown in the rotational detection coil BRSC3 / TRSC3. More specifically, the via VIA1D is at a position in the rotational detection coil BRSC4 / TRSC4 that is symmetrically / mirroring the position of the via VIA1C in the rotational detection coil BRSC3 / TRSC3 (e.g., such that a line between the position of the via VIA1C and the position of the via VIA1D passes through the central axis of the structure, and each position is equidistant from the central axis). The via VIA1D thereby balances the offset created by the via VIA1C as described above. More specifically, the unconnected component VIA1D is disposed within the rotation detection coil BRSC4 / TRSC4 (first rotation detection coil) and is symmetrically opposite (i.e., axially opposite) the similar electronically connected component VIA1C disposed within the rotation detection coil BRSC3 / TRSC3 (second rotation detection coil), and the unconnected component VIA1D thereby reduces a signal offset that occurs in the signal components provided by the rotation detection coils BRSC3 / TRSC3 and BRSC4 / TRSC4 due to the presence of the connected component VIA1C within the rotation detection coil BRSC3 / TRSC3.

[0102] In the embodiment of FIG. 11, the normalization coil R N The via for connecting the part VIA1C is axial Shown in close proximity to the connection vias for the detection coil structures TASCC and BASCC. Normalization coil R Nhas an upper portion and a lower portion, the upper portion extending radially in a straight line and connected by a via VIA1C to the lower portion, which also extends radially in a straight line. (The lower portion is not shown in FIG. 11 because it is obscured by other components for simplicity, but is located directly below the upper portion.) In various embodiments, the normalization coil R N is used to provide a measure of the transmit field (i.e., normalized coil R) (e.g., corresponding to the varying magnetic flux generated by the field generating coil arrangement (also called field generating coil substrate) 1160). N is utilized to provide a measurement of the varying magnetic flux generated by the field-generating coil arrangement 1160), where the measured signal is relatively independent of the position of the disruptor elements 1151T, 1151B (e.g., may be only nominally affected by the position of the disruptor elements 1151T, 1151B). In various embodiments, the position measurement may be made relatively insensitive to variations in transmit amplitude (from the field-generating coil arrangement 1160) in this measured signal. In various embodiments, such processing may be performed by signal processing and control circuitry (e.g., signal processing and control circuitry 380 of FIG. 2).

[0103] 9A, 9B, 10 and 11, in a manner similar to that described above with reference to Figures 2-8F, the rotational detection coil sections RSC (as shown in TRSC1-TRSC4 and BRSC1-BRSC4) output at least first and second rotational signal components RSigs indicative of the rotational position (such as X and Y position signals) of the stylus coupling section 342 (see Figure 2) on corresponding signal lines, and the axial detection coil arrangement ASCC (as shown in TASCC and BASCC) outputs one or more axial signal components ASigs indicative of the axial position (e.g., Z position signal) of the stylus coupling on corresponding signal lines. In various embodiments, the signal processing and control circuitry 380 (see Figure 2) receives the rotational signal components RSigs and the axial signal components ASigs and can perform various levels of associated signal processing in various embodiments. For example, in one embodiment, signal processing and control circuits combine and / or process signal components from the various receive coils in various relationships and provide the resulting rotational and axial position signal outputs RPSOut and APSOut in the desired output format via mount 224 (see FIG. 2). Referring to FIG. 2, one or more receive units (e.g., in CMM 200, motion controller 115, host computer 120, etc.) can receive the rotational and axial position signal outputs RPSOut and APSOut, and one or more associated processing and control units can be utilized to determine the three-dimensional position of the stylus coupling unit 342 and / or the contact portion of the attached stylus 306 as its contact portion 348 moves along the surface of the workpiece W being measured. The number, size, and shape of the receive coils, field-generating coils, and conductive plates or loops of the disruptor element used in various embodiments can be selected based on desired operating characteristics, such as improved position detection and reduced higher-order nonlinearities. Note that lower-order nonlinearities can be calibrated out by the CMM.

[0104] 9A, 9B, 10, and 11 facilitate the use of fewer mechanical parts because in some embodiments only one board is required for mounting (e.g., no flexible cables between separate boards are required). Such embodiments also facilitate improved repeatability and reduced assembly costs due to fewer degrees of freedom for alignment of the receive coil, and may be less sensitive to tilt and rotation issues that can occur in multi-board embodiments, e.g., with respect to XY positioning signals.

[0105] Figures 12A and 12B show an alternative arrangement of a stylus position detector 1211 which may be employed in the scanning probe 300 of Figure 2 as, for example, stylus position detector 311, such as in place of stylus position detector 511 in the embodiment of Figure 4 or in place of stylus position detector 411 in the embodiment of Figure 3. The stylus position detector 1211 uses an inductive detection principle and comprises a disruptor arrangement 1250 and a coil substrate arrangement 1290. The disruptor arrangement 1250 as shown comprises a generally cylindrical disruptor (cylindrical disruptor element) 1251. The illustrated coil substrate arrangement 1290 has a generally disc-shaped arrangement and is shown in more detail in Figure 12B.

[0106] As shown, the disruptor (cylindrical disruptor element) 1251 is positioned within a central opening (hole) 1291 of the coil substrate structure 1290 and extends in the Z direction of the disk-shaped coil substrate structure 1290. While the example of FIGS. 12A and 12B shows the disruptor 1251 extending in the Z direction above and below the coil substrate structure 1290, it will be understood that this is not necessarily the case in other embodiments (e.g., in various alternative embodiments, the disruptor 1251 may be the same length as or shorter than the coil substrate structure 1290 in the Z direction). In various embodiments, it is the cylindrical shape of the disruptor 1251, rather than its height along the Z direction, that is the more significant factor (which results in various desirable operating characteristics, as described in more detail below, e.g., with respect to FIGS. 14A-14D ).

[0107] As shown, coil substrate structure 1290 includes a field-generating coil structure 1260 having two transmit coils (field-generating coils) 1261T and 1261B and a receive coil section 1270. Receive coil section 1270 may include a rotational detector coil section (also referred to as a rotational detector coil) RSC (for a detection operation transverse to the axial direction, e.g., as described above with reference to Figures 3-6, etc.) and an axial detector coil structure ASCC (for a detection operation along the axial direction, e.g., as described above with reference to Figures 3-6, etc.).

[0108] Briefly, the moving disruptor element 1251 (or more generally, the disruptor arrangement 1250) causes position-dependent variations in the changing magnetic field produced by the field-generating coil arrangement 1260. The receive coil section 1270 responds to the changing magnetic field and the variations therein caused by the disruptor element 1251.

[0109] As shown, coil substrate assembly 1290 includes a first substrate portion 1292 having upper axial detection coil TASCC and field generating coil 1261T, a second substrate portion 1294 having lower axial detection coil BASCC and field generating coil 1261B, and a central substrate portion 1296 disposed between first substrate portion 1292 and second substrate portion 1294. Central substrate portion 1296 includes upper rotational detection coils TRSC1-TRSC4 and upper normalization coil TR N and the lower normalization coil BR N and lower rotation detection coils BRSC1 to BRSC4.

[0110] The coil substrate structure 1290 is mounted in fixed relationship to the frame of the scanning probe (see scanning probe 300 in FIG. 2 and frame 408 in FIG. 4), with a second substrate portion 1294 of the coil substrate structure 1290 closer to the stylus suspension portion 307 / 407 (see FIGS. 2 and 3). The first substrate portion 1292, second substrate portion 1294 and central substrate portion 1296 of the coil substrate structure 1290 are nominally parallel to one another and nominally orthogonal to the central axis CA (see FIG. 3) of the scanning probe 300 (see FIG. 2). The coil substrate structure 1290 may comprise, for example, a double-sided board or printed circuit board with a coil fabricated by printing conductors into the layers of the board or printed circuit board, a free-standing coil connected to a board or printed circuit board, and / or various combinations thereof.

[0111] In various embodiments, the disruptor element 1251 of the disruptor arrangement 1250 may comprise a conductive cylinder providing a disruptor region, with the disruptor element 1251 disposed along a central axis CA (see FIG. 3) within a disruptor movement volume extending on either side of the coil substrate arrangement 1290. The disruptor element 1251 is coupled to the stylus suspension 307 / 407 (see FIGS. 2 and 3) in a fixed relationship to each other by a coupling arrangement 1253 that includes an upper portion of the moving member 1212 (e.g., similar to moving member 412 of FIG. 3). The disruptor element 1251 moves within the disruptor movement volume relative to an undeflected position in response to deflection of the stylus suspension 307 / 407 (see Figures 2 and 3), and the disruptor element 1251 moves along the axial direction through an operational range of movement + / -Rz in response to axial movement, and along orthogonal X and Y directions orthogonal to the axial direction through respective operational ranges of movement + / -Rx and + / -Ry in response to rotational movement. The field generating coil arrangement 1260 generates a varying magnetic flux generally along the axial direction within the disruptor movement volume in response to coil drive signals.

[0112] As discussed above with respect to FIG. 11, in various embodiments, the upper normalization coil TR N and the lower normalization coil BRN may be utilized to provide a measurement of the transmit field (e.g., corresponding to the varying magnetic flux generated by the field-generating coil arrangement 1260), such that the measured signal may be relatively independent of (e.g., only nominally affected by) the position of the disruptor element 1251. In various embodiments, the position measurement may be scaled to this measured signal to make it relatively insensitive to variations in transmit amplitude (from the field-generating coil arrangement 1260). In various embodiments, such processing may be performed by signal processing and control circuitry (e.g., signal processing and control circuitry 380 of FIG. 2).

[0113] 13A-13F show an embodiment of a stylus position detector 1311 similar to the stylus position detector 1211 shown in FIGS. 12A and 12B, highlighting particular features in accordance with the principles disclosed herein.

[0114] Figure 13A is a partial schematic isometric view of an embodiment of a stylus position detector 1311 similar to the stylus position detector 1211 shown in Figures 12A and 12B. It will be understood that, in general, the stylus position detector 1311 comprises certain components that are similar to the components of the stylus position detectors 311, 411, 511, and 911 of Figures 2, 3, 4, 9A, and 9B, and operate similarly except as otherwise described below. The stylus position detector 1311 configuration may be used, for example, as the stylus position detector 311 in the scanning probe 300 of Figure 2, in place of the stylus position detector 411 in the embodiment of Figure 3, in place of the stylus position detector 511 in the embodiment of Figure 4, in place of the stylus position detector 911 in the embodiment of Figures 9A and 9B, in place of the stylus position detector 1211 in the embodiment of Figures 12A and 12B, etc.

[0115] In the embodiment shown in Figure 13A, the stylus position detection portion 1311 comprises a coil substrate arrangement 1390 and a disruptor arrangement 1350. In various embodiments, the disruptor element 1351 (or more generally the disruptor arrangement 1350) comprises a conductive cylinder or other desired operating arrangement that provides a disruptor region (e.g., an interior region thereof). As illustrated in Figure 13A, the disruptor element 1351 comprises a conductive cylinder. The disruptor element 1351 is disposed along a central axis CA of a disruptor moving volume MV that extends opposite the coil substrate arrangement 1390 and is coupled to the stylus suspension by a coupling arrangement (e.g., including at least an upper portion of a moving member 1312 similar to moving member 412 of Figure 3). For purposes of explanation, the disruptor element 1351 moves relative to an undeflected position shown in Figure 13A (e.g., similar to the undeflected position UNDF of Figure 3) in response to deflection of the stylus suspension 1307 and / or stylus 1306 and / or moving member 1312 (which may, for example, be similar to or identical to the stylus suspension 407, stylus 406 and moving member 412 of Figure 3). The disruptor element 1351 may be described as moving in displacement increments ΔZ along the axial direction over an operational range of travel + / -Rz in response to axial movement, and moving in respective displacement increments ΔX and ΔY over an operational range of travel + / -Rx and + / -Ry along orthogonal X and Y directions orthogonal to the axial direction (Z direction) in response to rotational movement.

[0116] The coil substrate arrangement 1390 comprises an upper coil substrate section 1390T and a lower coil substrate section 1390B. The upper coil substrate section 1390T includes an upper axial detection coil arrangement TASCC (e.g., consisting of a single illustrated individual coil in this embodiment), at least a first upper field-generating coil arrangement 1361T, N upper rotational detection coils TRSC (e.g., TRSC1-TRSC4 as illustrated, where N=4), and an upper normalization coil arrangement (upper normalization coil) TR N The lower coil substrate part 1390B includes a lower normalizing coil structure (lower normalizing coil) BR N, N lower rotating detection coils BRSC (e.g., BRSC1 to BRSC4 as shown, where N=4), at least a first lower field generating coil arrangement 1361B, and a lower axial detection coil arrangement BASCC (e.g., consisting of a single illustrated individual coil in this embodiment).

[0117] The coil substrate arrangement 1390 is mounted in fixed relation to the frame of the scanning probe (e.g., frame 408 of FIG. 4 ) at a lower coil substrate portion 1390B that is closer to the stylus 1306 and / or stylus suspension 1307. With respect to the various detector coils shown in FIG. 13A , it will be understood that all coils comprise at least one winding or conductor having first and second connection ends (e.g., as depicted in FIG. 6 ) configured to operate as one or more inductively coupled “turns.” As shown, the upper and lower axial detector coil arrangements TASCC and BASCC, as well as the upper and lower rotational detector coil arrangements TRSC and BRSC, are nominally symmetrically spaced relative to corresponding positions of the disruptor arrangement 1350 and disruptor element 1351. Other configurations are possible (eg, in some embodiments, the rotating detection coil arrangements TRSC and BRSC may not be nominally centered with respect to the disruptor arrangement 1350).

[0118] 13A, at least a first upper field-generating coil arrangement comprises a single upper field-generating coil (upper field-generating coil arrangement) 1361T having an area larger than the area of ​​the disruptor element 1351, and at least a first lower field-generating coil arrangement comprises a single lower field-generating coil (lower field-generating coil arrangement) 1361B having an area larger than the area of ​​the disruptor element 1351. The upper coil substrate portion 1390T and the lower coil substrate portion 1390B are nominally planar, nominally parallel to each other, and nominally perpendicular to the central axis CA.

[0119] Figures 13B-13E show an exemplary embodiment of the coil of the coil substrate construction 1390 of Figure 13A. Figure 13F shows an exemplary stackup of the coil of the coil substrate construction 1390 of Figure 13A. Figures 13A-13E show connection pads or vias (see Figure 13B) that may be similar to the connection pads or vias as described above in the description of Figure 11.

[0120] 13B, an exemplary embodiment of an upper axial detector coil arrangement TASCC or a lower axial detector coil arrangement BASCC is shown. As shown, a single coil is employed as the upper axial detector coil arrangement TASCC and a single coil is employed as the lower axial detector coil arrangement BASCC.

[0121] 13C, an exemplary embodiment of an upper field-generating coil arrangement 1361T or a lower field-generating coil arrangement 1361B is shown. As shown, a single coil is employed as the upper field-generating coil arrangement 1361T and a single coil is employed as the lower field-generating coil arrangement 1361B.

[0122] 13D shows an exemplary embodiment of the upper rotary detector coil arrangement TRSC or the lower rotary detector coil arrangement BRSC. As shown, four coils TRSC1 to TRSC4 are employed as the upper rotary detector coil arrangement TRSC, and four coils BRSC1 to BRSC4 are employed as the lower rotary detector coil arrangement BRSC.

[0123] In FIG. 13E, the upper normalized coil structure TR N or the lower normalization coil structure BR N As shown, a single coil is positioned in the upper normalized coil configuration TR N A single coil is employed as the lower normalized coil configuration BR N It is adopted as.

[0124] 13F shows an exemplary embodiment of layers of a coil substrate construction 1390. As described above with reference to FIG. 13A, the coil substrate construction 1390 comprises an upper coil substrate section 1390T and a lower coil substrate section 1390B. The upper coil substrate section 1390T, in turn, comprises a first layer having an upper axial detection coil construction TASCC, a second layer having at least a first upper field-generating coil construction 1361T, a third layer having N upper rotational detection coils TRSC, and an upper normalization coil construction TR N The lower coil substrate section 1390B is generally a mirror image of the upper coil substrate section 1390T and includes a lower normalized coil configuration BR N a second layer having N lower rotary detection coils BRSC, a third layer having at least a first lower field generating coil arrangement 1361B, and a fourth layer having a lower axial detection coil arrangement BASCC. The disruptor element 1351 as shown is a conductive cylinder extending above and below the coil substrate arrangement 1390.

[0125] As noted above, in the embodiments shown in Figures 3, 4, and 5, the disruptor elements are positioned inside the field-generating coil elements (e.g., disruptor element 551 of Figure 4 fits inside field-generating coil 561), with the area of ​​the disruptor elements being smaller than the area of ​​the field-generating coil elements. In the embodiments shown in Figures 9A, 9B, and 10, the disruptor elements are positioned parallel to the field-generating coil elements (e.g., disruptor elements 1051T, 1051B are positioned above and below field-generating coil 1061). In the embodiments shown in Figures 12A, 12B, and 13A-13F, a single tall, cylindrical disruptor element 1251 / 1351 fits within a hole 1291 surrounded by the coil elements, thereby providing increased flexibility in the configuration of the coil-substrate structure elements relative to their size and position. On the other hand, utilizing a single printed circuit board (e.g., the top and bottom substrate portions may comprise portions of a single multilayer printed circuit board) may reduce cost and complexity relative to configurations utilizing multilayer printed circuit boards. Furthermore, as discussed in more detail below with respect to Figures 14A-14D, the embodiments of Figures 12A, 12B, and 13A-13F may provide a significant reduction in resonant frequency change (RFC) resulting from displacement along the Z-axis, as well as reduced off-axis crosstalk, resulting in improved overall performance of the CMM.

[0126] Because some embodiments require only one substrate to be attached (e.g., separate inter-substrate flexible cables may not be necessary) and can use a single-height disruptor element that does not need to be disassembled to attach or remove the substrate, the embodiments of FIGS. 12A, 12B, and 13A-13F can facilitate the use of fewer mechanical components. Such embodiments also facilitate improved repeatability and lower assembly costs because the receive coils may have fewer degrees of freedom for alignment. Therefore, such embodiments may be less sensitive to tilt and rotation issues that can arise in multi-substrate embodiments, for example, with respect to XY positioning signals. Such embodiments can also improve off-axis crosstalk, frequency stability, and linearity.

[0127] 14A-14C show exemplary frequency shifts and off-axis crosstalk errors for the embodiments shown in FIGS. 3, 4, and 5, the embodiments shown in FIGS. 9A, 9B, and 10, and the embodiments shown in FIGS. 12A, 12B, and 13A-13F. FIG. 14A shows exemplary off-axis crosstalk errors for the embodiments shown in FIGS. 3, 4, and 5 when the displacement of a disruptor (e.g., disruptor element 551 in FIG. 4) along the Z axis is swept from −1 mm to +1 mm and U, V=1.1 degrees. FIG. 14B shows exemplary off-axis crosstalk errors for the embodiments shown in FIGS. 9A, 9B, and 10 when the displacement of a disruptor (e.g., disruptor element 951 in FIG. 9A) along the Z axis is swept from −1 mm to +1 mm and U, V=1.1 degrees. FIG. 14C shows exemplary off-axis crosstalk errors for the embodiments shown in FIGS. 12A, 12B, and 13A-13F when the displacement of a disruptor (e.g., disruptor structure 1250 of FIG. 12A) along the Z axis is swept from -1 mm to +1 mm and U, V = 1.1 degrees. In each of FIGS. 14A-14C, the V-shaped Z signal is the primary (linear) positioning signal, and the X and Y signals indicate the magnitude of crosstalk in the U, V directions. As can be seen, the off-axis crosstalk errors are highest for the embodiments of FIGS. 9A, 9B, and 10, ranging from 32 to 45 mV / V for the X and Y axes, where 40% of the nominal signal range is thus crosstalk (i.e., (45 to 32) / 32 = 40%). The embodiments of Figures 3, 4, and 5 have off-axis crosstalk errors in the range of 16-20 mV / V for the X and Y axes, where 25% of the nominal signal range is thus crosstalk (i.e., (20-16) / 16 = 25%), a moderate improvement. The off-axis crosstalk errors are lowest for the embodiments of Figures 12A, 12B, and 13A-13F, where 7% of the nominal signal range is thus crosstalk (i.e., (16-15) / 15 = 7%).

[0128] FIG. 14D shows an example of the change in resonant transmitter frequency as the stylus position detector (SPDP) displacement varies between 0 mm and 2 mm for the embodiments shown in FIGS. 3, 4, and 5, the embodiments shown in FIGS. 9A, 9B, and 10, and the embodiments shown in FIGS. 12A, 12B, and 13A-13F. At 0 mm displacement, the resonant frequency is the same for the various embodiments. The resonant frequency change (RFC) at 2 mm SPDP displacement is greatest for the embodiments of FIGS. 9A, 9B, and 10 (labeled SPDP1011 in FIG. 14D) and least for the embodiments of FIGS. 12A, 12B, and 13A-13F (labeled SPDP1311 in FIG. 14D). The embodiment of Figures 3, 4, and 5 (labeled SPDP411 in Figure 14D) has an RFC that is slightly larger than that of the embodiments of Figures 12A, 12B, and 13A-13F, but significantly smaller than that of the embodiments of Figures 9A, 9B, and 10. As can be seen, the embodiments of Figures 12A, 12B, and 13A-13F have less change in inductance with changing displacement along the Z axis, resulting in a smaller RFC at the disruptor location in addition to minimal off-axis crosstalk.

[0129] In various embodiments, particularly in single-substrate embodiments, at least some signal offset errors may occur due to printed circuit board (PCB) manufacturing tolerances, such as inter-layer coil registration errors. For example, misalignment between a field-generating coil arrangement and a rotational detection coil arrangement (RSC) may occur due to substrate manufacturing tolerances. In accordance with principles disclosed herein, one or more misalignment compensation elements may be added to a coil substrate arrangement to compensate for misalignment of the coils (e.g., coils of the first, second, and / or center substrate portion coil arrangements, etc.) relative to one another. More specifically, as described in more detail below, various embodiments may configure / utilize one or more misalignment compensation elements to reduce signal offsets resulting from misalignment of at least one coil of a coil substrate arrangement (e.g., a coil substrate arrangement may comprise a printed circuit board having multiple layers on which coils are disposed, and misalignment of at least one coil may result from registration errors, such as within manufacturing tolerances, in inter-layer registration as part of the manufacturing process).

[0130] 15A-15C show embodiments in which the misalignment compensation element takes the form of shielding added to reduce the effects of registration errors between a field-generating coil arrangement (e.g., field-generating coils 1261T and 1261B of FIG. 12B) and a rotating detection coil (rotating detection coil arrangement) (e.g., TRSC1-TRSC4 and BRSC1-BRSC4 of FIG. 12B). FIG. 15A illustrates an inner shield, in which copper pads are added to the field-generating coil (e.g., field-generating coils 1261T and 1261B of FIG. 12B), and an outer shield 1263, in which copper pads are located on the exterior of the shielded field-generating coil 1261′. 15B is a top view illustrating the alignment of the shielded field-generating coil 1261′ with the rotational detection coil (rotational detection coil configuration) RSC (e.g., TRSC1-TRSC4 or BRSC1-BRSC4) and the outer shielding 1263 with respect to the central axis of the stylus position detection portion (e.g., central axis CA in FIG. 13A ). As shown, copper pads are added to the field-generating coil 1261 to extend the area of ​​the shielded field-generating coil 1261′ to generally match the area of ​​the inner loop of the rotational detection coil RSC. And, the copper pads of the outer shielding 1263 are shaped and positioned to generally match the area of ​​the outer loop of the rotational detection coil RSC.

[0131] 15C illustrates an exemplary embodiment of layers of a coil substrate construction 1590. As shown, the coil substrate construction 1590 comprises an upper coil substrate section 1590T and a lower coil substrate section 1590B. The upper coil substrate section 1590T, in order, comprises a first layer having an upper axial detection coil construction TASCC, a second layer having at least a first shielded upper field generating coil construction 1261T′ and an outer shield 1263T, a third layer having N upper rotational detection coils TRSC, and an upper normalization coil construction TR N The lower coil substrate section 1590B is generally a mirror image of the upper coil substrate section 1590T and includes a lower normalized coil configuration BR Na second layer having N lower rotating detection coils BRSC; a third layer having at least a first shielded lower field generating coil arrangement 1261B′ and an outer shield 1263B; and a fourth layer having a lower axial detection coil arrangement BASCC.

[0132] Some embodiments may employ inner shielding (e.g., shielded field-generating coil 1261′) without outer shielding (e.g., outer shielding 1263), some embodiments may employ outer shielding (e.g., outer shielding 1263) without inner shielding (e.g., shielded field-generating coil 1261′), and some embodiments may employ both inner shielding (e.g., shielded field-generating coil 1261′) and outer shielding (e.g., outer shielding 1263). Shielding 1261′, 1263 makes the generated field smaller and more uniform at the ends of the rotating detection coil, reducing the effects of registration errors between the field-generating coil and the rotating detection coil. As shown in the table below, inner and outer shielding facilitates a 77% reduction in offset with only a 5% reduction in gain.

[0133] [Table 1]

[0134] Referring to FIG. 12B , FIG. 16 illustrates an exemplary embodiment of a stylus position detection unit 1211′ in which a misalignment compensation element in the form of a pin 1298 (which may, for example, in various embodiments, comprise a pin, pad, or the like) is added to the coil substrate structure to compensate for signal offset errors by introducing a compensating offset signal. In various embodiments, the pin can extend through the entire coil substrate structure, or only a portion thereof, or may be disposed on one layer of the coil substrate structure. As shown, the one or more pins may include multiple pins disposed on one side of the coil substrate structure 1290′ relative to a plane containing the central axis (see, for example, FIG. 13A ). The pins are then generally parallel to the central axis to compensate for misalignment of one or more rotational detection coils with respect to the field-generating coil structure. More specifically, in various embodiments, the pin arrangement may be utilized to increase or decrease the magnetic field through individual coils to compensate for coil misalignment.

[0135] With reference to FIG. 12B, FIG. 17A shows an exemplary embodiment of a stylus position detector 1211″ in which a mechanical adjustment mechanism 1297 is used to adjust the relative position of the coil substrate assembly 1290″ and / or the disruptor assembly 1250 (e.g., the relative X, Y and / or Z position of the coil substrate assembly 1290″ or the disruptor assembly 1250 relative to each other and / or relative to the housing / enclosure of the coil substrate assembly 1290″). In various embodiments, the coil substrate assembly 1290″ can include additional spacing (e.g., at the ends and / or center) to provide an adjustable positioning range. It will be appreciated that the mechanical adjustment mechanism 1297 may be utilized to reduce misalignment conditions. In an exemplary embodiment, overall correction for misalignment may be provided using one or more other misalignment compensation elements (e.g., pads or pins 1298 of FIG. 16, shielding 1261′ (shielded field generating coil 1261′) of FIGS. 15A-15C, 1263, adjustable coil TASCC′ (described below) of FIGS. 18A-18C, etc., and / or various combinations thereof), with fine position adjustment provided by mechanical adjustment mechanism 1297 to reduce any residual misalignment error or improve the effectiveness of other misalignment compensation elements.

[0136] As shown, the mechanical position adjustment mechanism 1297 includes set screws 1297A, 1297B. A first set screw 1297A (or multiple first set screws 1297A) facilitates adjustment of the relative XY position of the coil substrate assembly 1290″, and a second set screw 1297B facilitates adjustment of the Z position of the disruptor assembly 1250 with respect to the coil substrate assembly 1290″. In various embodiments, the set screws 1297A pass through and adjust the position of the alignment and mounting portion 1217 to which the coil substrate assembly 1290″ is attached or otherwise coupled. An enclosure 1208′ (e.g., part of or coupled to a body frame such as frame 408 in FIG. 4) surrounds the coil substrate assembly 1290″ and includes spacers SP that operate in conjunction with the relative movement. As described above (e.g., with respect to FIG. 12A ), the disruptor element 1251 travels within the hole 1291 in the coil substrate structure 1290″ and is coupled to the stylus suspension (see, e.g., suspension 307 / 407 / 407′ in FIGS. 2-4 ) by a coupling structure 1253 that comprises an upper portion of the moving member 1212 (e.g., similar to moving member 412 in FIGS. 3 and 4 ). In various embodiments, the second set screw 1297B may be included as part of the coupling structure 1253 or may operate in conjunction with the coupling structure 1253, such that the coupling structure 1253 may be at least partially adjustable. To that end, as described above, the second set screw 1297B facilitates adjustment of the Z position of the disruptor element 1251 relative to the coil substrate structure 1290″.

[0137] 4, FIG. 17B illustrates an exemplary embodiment of a stylus position detector 511″ in which a mechanical adjustment mechanism 597 is used to adjust the relative position of the coil substrate arrangement 590″ and / or the disruptor arrangement 550 (e.g., the relative X, Y, and / or Z position of the coil substrate arrangement 590″ or the disruptor arrangement 550 relative to each other and / or the housing / enclosure of the coil substrate arrangement 590″, etc.). In various embodiments, the coil substrate arrangement 590″ (e.g., comprising the substrates 571T, 571B, and the field-generating coil 561 and / or its substrate) can include additional spacing (e.g., at the ends and / or center) to provide an adjustable positioning range. It will be appreciated that the mechanical adjustment mechanism 597 may be utilized to reduce misalignment conditions, similar to the operations described above with respect to FIG. 17A.

[0138] As shown, the mechanical position adjustment mechanism 597 includes set screws 597A, 597B. A first set screw 597A (or multiple first set screws 597A) facilitates adjustment of the relative XY position of the coil substrate assembly 590'', and a second set screw 597B facilitates adjustment of the Z position of the disruptor assembly 550 with respect to the coil substrate assembly 590''. In various embodiments, the set screws 597A extend through and adjust the position of the alignment and mounting portion 517 to which the coil substrate assembly 590'' is attached or otherwise coupled. An enclosure 508' (which may be coupled to or part of a body frame, such as frame 408 in FIG. 4, for example) surrounds the coil substrate assembly 590'' and includes spacers SP that operate in conjunction with the relative movement. In various embodiments, the disruptor element 551 travels within a hole 591 in the coil substrate arrangement 590'' (e.g., within the field-generating coil 561 and its substrate) and is coupled to the stylus suspension (see, e.g., stylus suspension 307 / 407 / 407' in Figures 2-4) by a coupling arrangement 553 that includes an upper portion of the moving member 412. In various embodiments, the second set screw 597B may be included as part of the coupling arrangement 553 or may operate in conjunction with it. The coupling arrangement 553 may thus be at least partially adjustable such that, as described above, the second set screw 597B facilitates adjustment of the Z position of the disruptor element 551 relative to the coil substrate arrangement 590''. In various embodiments, a portion of the second set screw 597B, the moving member 412, and / or other portions of the coupling construct 553 can move within the hole 591B in the substrate 571B (e.g., in some embodiments, the substrate 571T can include a similar hole 591T that can provide access to the second set screw 597B for adjustment). With respect to Figures 17A and 17B, it will be understood that certain components shown with or without hash lines may include holes or openings (e.g., to allow certain relative motion, etc.).An example of such relative movement of the disruptor elements 551, 1251 within the respective stylus position detection units 511'', 1211'' may be understood based at least in part on the illustration of Figure 3 regarding the relative movement of the disruptor elements 451 within the stylus position detection unit 411.

[0139] With reference to FIG. 12B , FIGS. 18A-18C illustrate exemplary embodiments in which a misalignment compensation element in the form of a conductive short 1299 (e.g., a zero-ohm resistor) can be added to the coil substrate construction 1290′″ to compensate for misalignment errors. More specifically, in various embodiments, the conductive short 1299 can be added (e.g., at a location such as shown in FIGS. 18B and 18C ) to adjust the current path, essentially adjusting the coil dimensions of one or more adjustable coils of the coil substrate construction 1290′″, thereby effectively nulling or otherwise compensating for a certain determined offset. In various embodiments, the adjustable coils are in outer layers at the top and / or bottom of the coil substrate construction 1290′″ (e.g., adjacent to or as part of the axial detection coil constructions TASCC′ or BASCC′ in FIG. 18A ). As such, the conductive short 1299 can be easily added or removed without requiring access to the inner layers of the coil substrate construction 1290′″.

[0140] In various embodiments, when the coil substrate construction is initially manufactured / produced, certain misalignment compensation elements (e.g., shields 1261′, 1263 in FIGS. 15A-15C ) may be included as part of the manufacturing / production (e.g., as a general technique to reduce any misalignment errors that may occur due to any misalignment of the coils). In various embodiments, after the coil substrate construction is manufactured / produced, measurements and / or testing may be performed to determine what offsets are present (e.g., due to coil misalignments that may have occurred during manufacturing / production). Based on such testing / measurements, a specific decision can be made regarding the application of one or more offset compensation techniques (e.g., such as those described above with respect to FIGS. 16 , 17A , 17B , and 18A-18C ). For example, with respect to the approaches of Figures 16, 18B, and 18C, a decision can be made based on such testing / measurements as to where a misalignment compensation element (e.g., a pin, a conductive short, etc.) should be placed / located / added to compensate for the offset and achieve a desired offset-compensated configuration. As another example, with respect to the approaches of Figures 17A and 17B, a decision can be made based on such testing / measurements (which may be performed first and / or after approaches such as Figures 16, 18B, and 18C have been performed to make larger adjustments and then the approaches of Figures 17A and 17B have been performed to make finer adjustments) as to what and / or how much of one or more adjustments should be made to compensate for the offset (e.g., the remaining offset) and achieve a desired offset-compensated configuration. In various embodiments, multiple iterations of one or more correction techniques (e.g., including iterative testing and / or active monitoring of any commanded offsets) can be performed, including continuing adjustments until a desired offset-compensated configuration (e.g., a configuration in which the respective offset errors are reduced to an acceptable level) is achieved.

[0141] Although Figures 15A-15C, 16, 17A, and 18A-18C have been generally described with reference to Figures 12B and 13A, the techniques described herein for compensating for and reducing / resolving offset errors can be used in other embodiments, such as those described above with respect to Figures 3, 4, and 5, and Figures 9A, 9B, and 10.

[0142] In various embodiments, at least some signal errors may occur due to crosstalk between components of the stylus position detection unit. In some embodiments, crosstalk may refer to when a signal or field generated by or in one circuit, channel, or component of a system produces an undesired effect in another circuit, channel, or component of the system. Such crosstalk may be induced by undesired coupling (e.g., capacitive, inductive, conductive, etc.) from one circuit, channel, or component to another circuit, channel, or component. For example, with respect to a particular configuration of a scanning probe as described herein, crosstalk may occur between any of the field-generating coil arrangements (including coupling thereto), the detection coil arrangements, and / or the disruptor arrangements. In accordance with the principles disclosed herein, as discussed in more detail below, one or more field-generating coil coupling and crosstalk cancellation arrangements CCRC couple signal processing and control circuitry (e.g., signal processing and control circuitry 480 of FIG. 4 , signal processing and control circuitry 680 of FIG. 6 ) to the field-generating coil arrangements to provide coil drive signals, while facilitating the reduction of crosstalk between various components of the stylus position detection portion. The field-generating coil coupling and crosstalk cancellation arrangements CCRC are configured to reduce crosstalk that would occur if the field-generating coil arrangements were directly connected to the signal processing and control circuitry without the use of the field-generating coil coupling and crosstalk cancellation arrangements.

[0143] As described in more detail below, Figures 19-24 illustrate various example embodiments in accordance with the principles disclosed herein. It will be appreciated that such principles may be utilized with various configurations and types of stylus position detectors and associated electronics, such as stylus position detectors 411, 511, 511', 911, 1011, 1111, 1211, 1211', 1211" and 1311 described above with respect to Figures 3-18. Furthermore, such principles may also be utilized with other configurations and / or combinations of the various components of such stylus position detectors.

[0144] In particular, Figures 19-24 show various embodiments of a stylus position detection unit 1911 using an inductive detection principle and comprising a coil substrate assembly 1990 and a disruptor assembly 1950. The field-generating coil substrate assembly 1990M of the coil substrate assembly 1990 as shown (e.g., in Figures 22-24) comprises a field-generating coil assembly 1960 having a multi-turn field-generating coil 1961 with two turns, and two corresponding field-generating coil sections 1961B and 1961T positioned approximately equidistant from the midplane of the disruptor movement volume along a central axis and nominally planar and orthogonal to the central axis. The field-generating coil sections may be coupled together by one or more vias. The coil substrate assembly 1990 may comprise one or more PCBs, each having one or more layers on which coils are disposed. For example, the coil substrate configuration 1990 may have a configuration similar to the multi-board coil substrate configuration of Figure 4, including a field-generating coil configuration 560 having a field-generating coil 561, as well as a receive coil section 570 having a planar upper coil substrate 571T and a planar lower coil substrate 571B. In another example, the coil substrate configuration 1990 may have a configuration similar to the coil substrate configuration 990 of Figure 9.

[0145] The disruptor element 1951 of the disruptor structure 1950 as shown is a single round, planar disruptor element. The disruptor structure 1950 may have other configurations, such as a configuration similar to the disruptor structure 550 of FIG. 5, the disruptor structure 950 of FIG. 9, or the disruptor structure 1250 of FIG. 12A and 12B. The stylus position detection section 1911 typically includes other components that are omitted from FIGS. 19-24 to simplify the illustrations, such as a receive coil section (see, e.g., receive coil section 570 of FIG. 5; receive coil section 970 of FIG. 9, receive coil section 1270 of FIG. 12B, etc.).

[0146] 19-24, field generating coil coupling and crosstalk cancellation arrangements CCRC-1 through CCRC-6 couple signal processing and control circuitry (e.g., signal processing and control circuitry 480 of FIG. 4; signal processing and control circuitry 680 of FIG. 6, etc.) to a field generating coil arrangement 1960 that, as described above, facilitates reducing crosstalk between various components of the stylus position detection unit 1911. The crosstalk reduced by field generating coil coupling and crosstalk cancellation structures CCRC-1 through CCRC-6 may be due to, for example, field generating coil structure 1960 and the various connections thereto, disruptor element 1951 of disruptor structure 1950, axial detection coils (not shown in FIGS. 19-24, see TASCC and BASCC in FIGS. 5, 6, and 12B), rotational detection coils (not shown in FIGS. 19-24, see TRSC1-4 and BRSC1-4 in FIGS. 5, 6, and 12B), and normalization coils (not shown in FIGS. 19-24, see TRSC1-4 and BRSC1-4 in FIG. 12B). N and B.R. N This may include crosstalk between various other components of the stylus position detection unit 1911, such as the

[0147] FIG. 19 illustrates an embodiment in which the field-generating coil coupling and crosstalk cancellation arrangement CCRC-1 comprises a conductive coupling portion CCP-1 and a conductive shield CSD-1. The conductive coupling portion CCP-1 comprises conductors CON-1961B and CON-1961T, which couple back to a signal processing and control circuit (such as signal processing and control circuit 480 in FIG. 4) via the conductive coupling portion CCP-1's flexible cable 1964. The conductive shield CSD-1 is shown adjacent to (e.g., covering) at least a portion of the conductors CON-1961B and CON-1961T (the conductive shield CSD-1 is shown as transparent to show the portion of the conductor CON-1961B that is shielded, but typically need not be transparent). While the flexible cable 1964 is shown in FIG. 19, other types of wires, cables, fibers, etc., or various combinations thereof, may be used as part of the conductive coupling portion CCP-1. Capacitor C2 is shown as being coupled between conductors CON-1961B and CON-1961T (e.g., as described in more detail below with respect to Figures 21-24, capacitor C2 may be coupled between the two vias where conductors CON-1961B and CON-1961T join, and in some embodiments may be part of a parallel capacitor arrangement PCC and / or part of a three-current branch arrangement TCB as part of a field-generating coil coupling and crosstalk cancellation arrangement).

[0148] The following describes current paths (e.g., AC current may flow in both directions, but for simplicity of the following examples will be described in relation to a single direction) for current flowing between signal processing and control circuitry (e.g., such as signal processing and control circuitry 480 of FIG. 4 ) and field generating coil 1961 (i.e., including field generating coil sections 1961B and 1961T). Note that such current paths for the following examples are illustrated in more detail in FIGS. 21-24 . Arrows are provided in FIGS. 19-24 to illustrate the direction of current flow associated with the described examples. It will be understood that with respect to AC current, the example current flow direction (i.e., one example direction) can be reversed in any of the embodiments and descriptions (e.g., FIGS. 19 and 20 are shown with a first direction of current flow, while FIG. 21 is shown with a second direction of current flow, but it will be understood that the direction is reversed in any of the examples).

[0149] As shown in portions of FIG. 19 (and also FIG. 20), for current flowing in the exemplary direction from the signal processing and control circuitry to the field-generating coil 1961, conductor CON-1961T is coupled to one side of capacitor C2 (e.g., via a via that may be coupled to field-generating coil portion 1961T of field-generating coil 1961, as described in more detail below with respect to FIGS. 21-24) and thus corresponds to the current path through those components. For current flowing along the return path in the exemplary direction from the field-generating coil 1961 to the signal processing and control circuitry, the other side of capacitor C2 is coupled to conductor CON-1961B (e.g., via a via that may be coupled to field-generating coil portion 1961B of field-generating coil 1961, as described in more detail below with respect to FIGS. 21-24).

[0150] Conductive shielding CSD-1 is shown as being adjacent to (e.g., covering) at least a portion of conductors CON-1961B and CON-1961T adjacent to field-generating coil 1961 (e.g., including field-generating coil portions 1961B and 1961T, as described in more detail below with respect to FIGS. 21-24). Conductive shielding CSD-1 may comprise a conductive shielding portion (e.g., comprising a narrow copper pad, sleeve, or mirrored conductive pad, etc.) adjacent to (e.g., covering the top and / or bottom, etc.) at least a portion of conductors CON-1961B and CON-1961T (e.g., including at least a portion adjacent to field-generating coil 1961 and disruptor element 1951).

[0151] It will be appreciated that if conductive shield CSD-1 were not included in the configuration of FIG. 19, certain types of crosstalk could occur (e.g., introduce errors into the rotation detection coil signal). For example, one type of crosstalk could be coupling between conductors CON-1961B, CON-1961T, and disruptor element 1951 (which may be referred to as a scale element) to generate a cable-coupled disruptor (scale) current CCScS. Such crosstalk may primarily affect a nominal disruptor current NScC on one side of disruptor element 1951, and because the coupling effect is different on different sides of disruptor element 1951, disruptor element 1951 may introduce errors into the rotation detection coil signal (see TRSC1-4 and BRSC1-4 in FIGS. 5, 6, and 12, not shown in FIG. 19). More specifically, in various embodiments, the effect may be greatest on the side of the disruptor element 1951 closest to (e.g., in close proximity to) the conductors CON-1961B, CON-1961T. The conductive shield CSD-1 reduces such coupling between the conductors CON-1961B, CON-1961T, and the disruptor element 1951 of the disruptor structure 1950, and therefore reduces the crosstalk resulting therefrom (e.g., the disruptor element 1951 may otherwise introduce crosstalk errors in the signals from the rotation detection coils). In various implementations, the conductive shield CSD-1 may itself introduce a relatively small offset in the XY direction, which in some configurations may be reduced / cancelled by a mirrored shielding structure, as described in more detail below with respect to FIG. 20 .

[0152] 20 illustrates an embodiment in which field-generating coil coupling and crosstalk cancellation structure CCRC-2 comprises conductive coupling portion CCP-2, conductive shield CSD-2, mirror stub conductive coupling portion CCP-2M, and mirror stub conductive shield CSD-2M. Conductive coupling portion CCP-2 comprises conductors CON-1961B and CON-1961T, which couple back to signal processing and control circuitry (such as signal processing and control circuitry 480 of FIG. 4) via conductive coupling portion CCP-2's flexible cable 1964. Conductive shield CSD-2 is shown as being proximate to (e.g., covering) at least a portion of conductors CON-1961B and CON-1961T that are proximate field-generating coil 1961 (e.g., comprising field-generating coil portions 1961B and 1961T, as described in more detail below with respect to FIGS. 21-24). Conductive shield CSD-2 may comprise a conductive shielding portion (e.g., comprising a narrow copper pad, a sleeve, or a mirrored conductive pad, etc.) adjacent to (e.g., covering, above and / or below, etc.) at least a portion of conductors CON-1961B and CON-1961T (e.g., comprising at least a portion adjacent to field-generating coil 1961 and disruptor element 1951). For ease of illustration, conductive shield CSD-2 is shown as transparent with respect to conductors CON-1961B and CON-1961T.

[0153] The larger size of conductive shield CSD-2 of Fig. 20 compared to conductive shield CSD-1 illustrated in Fig. 19 can add shielding between the disruptor arrangement 1950 and the coupling associated with the field generating coil arrangement 1960 and reduce corresponding coupling, and therefore crosstalk (e.g., that may undesirably affect signals in the rotation detection coil arrangement). In various embodiments, the increased reduction in coupling provided by the larger conductive shield CSD-2 of Fig. 20 compared to the configuration of Fig. 19 can potentially come at the cost of introducing a larger offset (e.g., in the X and Y directions), although such factors can be considered and balanced when selecting a shield size for a given application.

[0154] Any offset that may be introduced by conductive shield CSD-2 will be primarily associated with one side of stylus position detection portion 1911. To reduce this offset, mirror stub conductive shield CSD-2M is configured to mirror conductive shield CSD-2 (e.g., on the opposite side of stylus position detection portion 1911 from conductive shield CSD-2). Additionally, to further reduce the offset, mirror stub conductive coupling portion CCP-2M is configured to mirror conductive coupling portion CCP-2 (e.g., on the opposite side of stylus position detection portion 1911).

[0155] The mirror stub conductive shield CSD-2M is at a second position relative to the central axis, and the first conductive shield CSD-2 is at a first position relative to the central axis, such that the first position and the second position are symmetrical about the central axis (e.g., on opposite sides of the stylus position detection portion 1911 in a plane perpendicular to the Z direction). Similarly, the mirror stub conductive coupling portion CCP-2M is at a second position relative to the central axis, and the first conductive coupling portion CCP-2 is at a first position relative to the central axis, such that the first position and the second position are symmetrical about the central axis (e.g., on opposite sides of the stylus position detection portion 1911 in a plane perpendicular to the Z direction). The mirror stub conductive coupling portion CCP-2M and mirror stub conductive shield CSD-2M and their symmetrical arrangement at least partially compensate for the offset introduced by the conductive coupling portion CCP-2 and the conductive shield CSD-2.

[0156] 20 also includes a first capacitor C1 proximate mirror stub conductive coupling portion CCP-2M and coupled in series with field-generating coil portions 1961B and 1961T of field-generating coil 1961, and a second capacitor C2 proximate field-generating coil arrangement 1960 and coupled between conductors CON-1961B and CON-1961T (e.g., coupled between two vias to which conductors CON-1961B and CON-1961T are coupled, as described in more detail below with respect to FIGS. 21-24). Thus, second capacitor C2 is in parallel with signal processing and control circuitry (e.g., signal processing and control circuitry 480 of FIG. 4; signal processing and control circuitry 680 of FIG. 6, etc.). The first capacitor C1 and the second capacitor C2 may be disposed symmetrically with respect to one another about the central axis and on or within a portion of the field-generating coil substrate portion 1990M, such as on or within the upper portion or on or within the lower portion of the field-generating coil substrate portion 1990M. For example, with reference to the field-generating coil plane FGCP defined by the field-generating coil 1961 (see, e.g., FIGS. 21-24), in various embodiments, the first capacitor C1 and the second capacitor C2 may be disposed above or below the field-generating coil plane.

[0157] In various embodiments, capacitors C1 and C2 match the characteristics of signal processing and control circuitry (e.g., signal processing and control circuitry 480 of FIG. 4 ; signal processing and control circuitry 680 of FIG. 6 ), and determine at least a portion of the impedance of the field-generating coil 1961 in a configuration that sets the LC resonant frequency (e.g., of the resonant loop RL comprising the field-generating coil 1961 and conductive coupling part CCP-2). In various embodiments, one of the primary purposes of the resonant loop RL is to increase the signal amplitude (e.g., so that it may function similarly to an electrical transformer for voltages, such as having a driver voltage of + / −2.5 V for the coil drive signal and achieving >+ / −5 V on the field-generating coil 1961). The resonant loop RL may also perform certain filtering functions, such as reducing noise coupling into the detection coil.

[0158] In various embodiments, placing the first capacitor C1 and the second capacitor C2 on one side of the field-generating coil plane FGCP defined by the field-generating coil 1961 may introduce some imbalance (e.g., electromagnetic fields, etc.) in the axial direction, which may introduce crosstalk and therefore errors in the generated signals (see, e.g., the TASCC and BASCC in FIGS. 5, 6, and 12B, due to axial detection coils not shown in FIGS. 19-24). In certain embodiments, the signal error introduced by placing the capacitor C2 on one side of the field-generating coil plane FGCP may be larger than the signal error introduced by placing the capacitor C1 on one side of the field-generating coil plane FGCP. To reduce such potential signal errors, in various embodiments (e.g., as described in more detail below with respect to Figures 21-24), one or both of capacitors C1 and C2 (e.g., preferably comprising at least capacitor C2 in certain embodiments) may be made to be part of a parallel capacitor arrangement PCC and / or part of a three-current branch arrangement TCB (e.g., with a corresponding additional capacitor on the opposite side of the field-generating coil plane FGCP).

[0159] In Figure 21, the field-generating coil coupling and crosstalk cancellation arrangement CCRC-3 includes a conductive coupling portion CCP-3 comprising conductors CON-1961B and CON-1961T, which couple back to a signal processing and control circuit (such as signal processing and control circuit 480 of Figure 4) via conductive coupling portion CCP-3's flexible cable 1964. Instead of a single capacitor C2 coupled across the connections to field-generating coil portions 1961B and 1961T as shown in Figure 20, the field-generating coil coupling and crosstalk cancellation arrangement CCRC-3 of Figure 21 includes a parallel capacitor arrangement PCC having a pair of capacitors C2U, C2L. Capacitor C2U is located above and capacitor C2L is located below the field-generating coil plane FGCP.

[0160] 21 (e.g., including capacitor C2L mirroring capacitor C2U) serves to improve axial and / or other symmetry of circuits / components / signals. More specifically, if a single capacitor C2 is just to one side (e.g., of the field-generating coil plane FGCP), the arrangement (e.g., along the axial direction) may otherwise be somewhat unbalanced / asymmetric (e.g., with respect to the field-generating coil plane FGCP), which may correspond to higher crosstalk and / or other imbalances in the signals (e.g., in the direction of the single capacitor). Such problems can be reduced by having symmetrical capacitors on either side of the mirrored configuration (e.g., of the field-generating coil plane FGCP), where the corresponding effects at least partially self-cancel and / or can otherwise be made more balanced (e.g., for upper and lower detection coils, such as the TASCC and BASCC of FIGS. 5, 6, and 12B). Otherwise, unbalanced signals can result in inaccurate position determination for the disruptor element / stylus suspension / stylus, etc. It will be appreciated that if such balanced / symmetrical coil signals are processed in a differential configuration, some portions of such balanced / symmetrical coil signals can effectively self-cancel. While FIG. 21 illustrates the use of a parallel capacitor configuration PCC in place of the single capacitor C2 shown in FIG. 20, a similar parallel capacitor configuration can also be used in place of the single capacitor C1 in some embodiments of FIG. 20.

[0161] The following describes the current paths (e.g., AC current may flow in both directions, but for simplicity of the following examples, will be described in relation to a single direction) for current flowing between signal processing and control circuitry (e.g., signal processing and control circuitry 480 of FIG. 4 ) and field-generating coil 1961 (i.e., including field-generating coil portions 1961B and 1961T). Arrows are provided in FIG. 21 to indicate the direction of current flow in accordance with the following description. Note that the couplings described below are shown in more detail in FIGS. 22-24 . As partially shown in FIG. 21 , for current flowing in the illustrated direction from the signal processing and control circuitry to field-generating coil 1961, conductor CON-1961B is coupled to via VIA-A, and thus corresponds to the current path through those components. For current flowing along the return path in the illustrated direction from field-generating coil 1961 to signal processing and control circuitry, via VIA-B is coupled to conductor CON-1961T, and thus corresponds to the current path through those components.

[0162] 21, for current flowing in the illustrated direction through parallel capacitor structure PCC (i.e., comprising capacitors C2U and C2L), capacitor C2U is coupled between the tops of vias VIA-A and VIA-B, and capacitor C2L is coupled between the bottoms of vias VIA-A and VIA-B. These correspond to the current paths through these series of components. More specifically, a portion of the current from conductor CON-1961B flows upward through the top of via VIA-A, downward through capacitor C2U, downward through the top of via VIA-B, and out through conductor CON-1961T. A portion of the current from conductor CON-1961B flows downward through the bottom of via VIA-A, downward through capacitor C2L, upward through the bottom of via VIA-B, and out through conductor CON-1961T. In various embodiments, capacitor C2U may be part of upper branch UB, and capacitor C2L may be part of lower branch LB of field-generating coil coupling and crosstalk cancellation configuration CCRC-3. In various embodiments, the current flow through each of upper branch UB and lower branch LB, and correspondingly through each of capacitors C2U and C2L, may be approximately equal (e.g., thus resulting in a balanced effect on the magnetic / electromagnetic fields, such as for upper and lower detection coils, such as the TASCC and BASCC of FIGS. 5, 6, and 12B, so that balanced / symmetrical coil signals may effectively self-cancel when processed in a differential configuration).

[0163] If capacitor C2L were omitted from FIG. 21, current would flow through capacitor C2U above the field-generating coil plane FGCP, but no corresponding current would flow below the field-generating coil plane FGCP. Such a configuration would result in relatively unbalanced effects (e.g., in the magnetic field) relative to the field-generating coil plane FGCP and, therefore, potentially crosstalk errors (e.g., from crosstalk corresponding to the effect of current through capacitor C2U) in the signals generated by the axial detection coils. Including capacitor C2L as part of a parallel capacitor arrangement PCC with capacitor C2U ensures that similar currents occur at approximately equal distances and in similar relative positions (e.g., with similar or identical X, Y coordinates) above and below the field-generating coil plane FGCP. Such a balanced arrangement (e.g., with respect to the field-generating coil plane FGCP) helps reduce possible errors (e.g., crosstalk errors) in determined position signals (e.g., resulting from signals generated in the axial detection coils).

[0164] 22, field-generating coil coupling and crosstalk cancellation arrangement CCRC-4 couples signal processing and control circuitry (such as, for example, signal processing and control circuitry 480 of FIG. 4) to field-generating coil 1961 (i.e., comprising field-generating coil portions 1961B and 1961T) of field-generating coil arrangement 1960. In the example of FIG. 22, field-generating coil coupling and crosstalk cancellation arrangement CCRC-4 comprises vias VIA-A, VIA-B, and VIA-C, capacitors C2U and C2L (e.g., as part of parallel capacitor arrangement PCC), conductive shielding CSD, and conductors CON-1961B and CON-1961T.

[0165] 22, as part of field-generating coil coupling and crosstalk cancellation arrangement CCRC-4 (e.g., as part of conductive coupling portion CCP-4), conductors CON-1961B and CON-1961T couple back to signal processing and control circuitry (e.g., such as signal processing and control circuitry 480 of FIG. 4), and therefore conductive shielding CSD is shown in close proximity to (e.g., covering) at least a portion of conductors CON-1961B and CON-1961T. In particular, conductive shielding CSD is shown in close proximity to (e.g., covering) at least a portion of conductors CON-1961B and CON-1961T that are in close proximity to field-generating coil 1961 (i.e., comprising field-generating coil portions 1961B and 1961T). As discussed above in the description of FIG. 19, in various embodiments, conductive shield CSD-1 may comprise a conductive shielding portion (e.g., comprising a narrow copper pad, a sleeve, or a mirrored conductive pad, etc.) adjacent to (e.g., covering, above and / or below, etc.) at least a portion of conductors CON-1961B and CON-1961T (e.g., comprising at least a portion adjacent to field-generating coil 1961 and disruptor element 1951).

[0166] As further discussed above in the description of Figure 19, if conductive shielding CSD were not included in the configuration of Figure 22, conductors CON-1961B and CON-1961T mounted proximate to just one side of the configuration would produce effects (e.g., electromagnetic field effects) that would be present primarily on one side of the configuration, leading to imbalances in the electromagnetic fields and corresponding signals detected by the detection coils (see, e.g., TRSC1-4 and BRSC1-4 in Figures 5, 6, and 12, etc.). Having conductive shielding CSD proximate to conductors CON-1961B and CON-1961T helps to reduce such effects on one side, thus improving the overall symmetry of the signal (i.e., reducing crosstalk effects on one side). For example, with respect to disruptor element 1951 (see, e.g., FIG. 19 ), in various embodiments, the effect may be greatest on the side of disruptor element 1951 that is closest to (e.g., in close proximity to) and therefore has the greatest amount of coupling to conductors CON-1961B, CON-1961T. The conductive shield CSD reduces such coupling (e.g., magnetic field coupling) between conductors CON-1961B, CON-1961T and disruptor element 1951 of disruptor structure 1950, and therefore reduces crosstalk resulting therefrom (e.g., that could otherwise result in crosstalk errors in signals from rotation detection coils, etc.).

[0167] The following describes current paths (e.g., AC currents may flow in both directions, but for simplicity of the following examples, will be described in relation to a single direction) for currents flowing between signal processing and control circuitry (e.g., signal processing and control circuitry 480 of FIG. 4 ) and field-generating coil 1961 (i.e., including field-generating coil portions 1961B and 1961T). Arrows are provided in FIG. 22 to indicate the direction of current flow, along with the following descriptions. For currents flowing in the illustrated direction from the signal processing and control circuitry toward field-generating coil 1961, conductor CON-1961B is coupled to via VIA-A, and thus corresponds to the current path through these components. For currents flowing along the return path in the illustrated direction from field-generating coil 1961 to the signal processing and control circuitry, via VIA-B is coupled to conductor CON-1961T, and thus corresponds to the current path through these components.

[0168] For current flowing in the illustrated direction through field-generating coil 1961, via VIA-A is coupled to one end of field-generating coil section 1961B, which in turn couples the other end of field-generating coil section 1961B to via VIA-C. Via VIA-C is coupled to one end of field-generating coil section 1961T, which in turn couples the other end of field-generating coil section 1961T to via VIA-B. Thus, via VIA-B corresponds to the current path for field-generating coil 1961 through its series of components. More specifically, in the direction shown in FIG. 22 , a portion of the current from conductor CON-1961B flows downward through the bottom of via VIA-A, clockwise through field-generating coil section 1961B, upward through via VIA-C so as to flow clockwise through field-generating coil section 1961T, then downward through the bottom of via VIA-B and out through conductor CON-1961T.

[0169] Additionally, as discussed above with respect to FIG. 21 , for current flowing in the illustrated direction through parallel capacitor structure PCC (i.e., comprising capacitors C2U and C2L), capacitor C2U is coupled between the tops of vias VIA-A and VIA-B, and capacitor C2L is coupled between the bottoms of vias VIA-A and VIA-B. Vias VIA-A and VIA-B correspond to a current path through these series of components. More specifically, a portion of the current from conductor CON-1961B flows upward through the top of via VIA-A, through capacitor C2U, downward through the top of via VIA-B, and out through conductor CON-1961T. And, a portion of the current from conductor CON-1961B flows downward through the bottom of via VIA-A, through capacitor C2L, upward through the bottom of via VIA-B, and out through conductor CON-1961T. In various embodiments, capacitor C2U may be part of upper branch UB and capacitor C2L may be part of lower branch LB of field generating coil coupling and crosstalk cancellation structure CCRC-4.

[0170] As mentioned above, in various embodiments, the field-generating coil 1961 defines a field-generating coil plane FGCP (e.g., located midway between field-generating coil sections 1961B and 1961T, such that conductors CON-1961B and CON-1961T may be in the same or similar locations where they contact vias VIA-A and VIA-B, respectively, and in various embodiments, such that at least a portion of conductors CON-1961B and CON-1961T may reside within the field-generating coil plane FGCP and may approximately bisect vias VIA-A and VIA-B). In various embodiments, the field-generating coil plane FGCP is orthogonal to the central axis and passes through the field-generating coil 1961, such that the upper branch UB (e.g., comprising capacitor C2U) and lower branch LB (e.g., comprising capacitor C2L) of the field-generating coil coupling and crosstalk cancellation structure CCRC-4 are located above and below the field-generating coil plane FGCP, respectively. In the example of FIG. 22, the upper branch UB and the lower branch LB are symmetrical with respect to the field-generating coil plane FGCP, are part of a mirrored current distribution configuration (e.g., the current through the lower branch LB is approximately the same as and mirrors the current through the upper branch UB), and are connected in parallel (e.g., connected in parallel across the top and bottom of vias VIA-A and VIA-B, respectively).

[0171] As discussed above with reference to FIG. 21 , if capacitor C2L were omitted from the configuration of FIG. 22 , current would flow through capacitor C2U above the field-generating coil plane FGCP, but no corresponding current would flow below the field-generating coil plane FGCP. Such a configuration could result in a relatively unbalanced effect (e.g., in the magnetic field) relative to the field-generating coil plane FGCP and, therefore, crosstalk errors (e.g., from crosstalk corresponding to the effect of current through capacitor C2U) in the signals generated by the axial detection coils. By including capacitor C2L as part of a parallel capacitor configuration PCC with capacitor C2U, similar currents are ensured to occur at approximately equal distances and at similar relative positions (e.g., with similar or identical X and Y coordinates) above and below the field-generating coil plane FGCP. Such a balanced configuration (e.g., with respect to the field-generating coil plane FGCP) helps reduce any corresponding errors (e.g., crosstalk errors) that might otherwise result in determined position signals (e.g., resulting from signals generated by the axial detection coils).

[0172] It will be appreciated that in embodiments in which multiple field-generating coils are utilized (see, e.g., field-generating coils 561T and 561B in FIGS. 5 and 6), a parallel capacitor arrangement PCC may be provided for coupling to each field-generating coil (e.g., such as signal processing and control circuit 680 in FIG. 6) for coupling to signal processing and control circuitry. In such embodiments, each field-generating coil may define a respective field-generating coil plane that is orthogonal to the central axis and passes through the respective field-generating coil, and thus each parallel capacitor arrangement PCC may include upper and lower legs (e.g., comprising respective capacitors) corresponding to positions above and below the respective field-generating coil plane.

[0173] In FIG. 23 , field-generating coil coupling and crosstalk cancellation arrangement CCRC-5 couples signal processing and control circuitry (e.g., signal processing and control circuitry 480, such as in FIG. 4 ) to field-generating coil 1961 (i.e., comprising field-generating coil sections 1961T and 1961B). In the example of FIG. 23 , field-generating coil coupling and crosstalk cancellation arrangement CCRC-5 comprises vias VIA-A through VIA-E, capacitors C2U and C2L (e.g., as part of parallel capacitor arrangement PCC), conductive shield CSD, and conductors CON-1961T′, CON-1961T″, CON-1961B′, and CON-DE. As explained in more detail below, the main difference from FIG. 22 is that in FIG. 23 , vias VIA-D and VIA-E and conductor CON-DE are provided as part of twist arrangement TWC.

[0174] 23, as part of field-generating coil coupling and crosstalk cancellation arrangement CCRC-5 (e.g., as part of conductive coupling portion CCP-5), conductors CON-1961T' and CON-1961B' couple back to signal processing and control circuitry (e.g., such as signal processing and control circuitry 480 of FIG. 4), and therefore conductive shielding CSD is shown in close proximity to (e.g., covering) at least a portion of conductors CON-1961T' and CON-1961B'. In particular, conductive shielding CSD is shown in close proximity to (e.g., covering) at least a portion of conductors CON-1961T' and CON-1961B' that are in close proximity to field-generating coil 1961 (i.e., comprising field-generating coil portions 1961B and 1961T).

[0175] The following describes current paths (e.g., AC currents may flow in both directions, but are described in relation to a single direction for simplicity of the following examples) corresponding to current flowing between signal processing and control circuitry (e.g., such as signal processing and control circuitry 380 of FIG. 2) and field-generating coil 1961 (i.e., including field-generating coil portions 1961T and 1961B). FIG. 23 provides arrows indicating the direction of current flow, along with the following description: For current flowing from the signal processing and control circuitry to field-generating coil 1961 in the illustrated direction, conductor CON-1961T′ is coupled to via VIA-D, which is coupled by conductor CON-DE to via VIA-E. Via VIA-E is coupled to via VIA-B by conductor CON-1961T″. Thus, the coupling between components from conductor CON-1961T′ to via VIA-B corresponds to a current path through that series of components. Via VIA-D, via VIA-E, and conductor CON-DE are part of twisted configuration TWC, as described in more detail below. For current flowing along the return path in the illustrated direction from field-generating coil 1961 to the signal processing and control circuitry, via VIA-A is coupled to conductor CON-1961B', and thus corresponds to the current path through those components.

[0176] Because the twisted structure TWC is in close proximity to just one side of the structure (e.g., as also described herein for the conductive shield CSD), it reduces effects that might otherwise be produced by conductors CON-1961B' and CON-1961T'. More specifically, conductors CON-1961B' and CON-1961T' produce effects / contributions (e.g., electromagnetic field effects / contributions) that are primarily on one side of the structure, which, if not introduced, might at least partially unbalance the electromagnetic fields and corresponding signals detected by the detection coils (e.g., see TRSC1-4 and BRSC1-4 in Figures 5, 6, and 12, etc.). The inclusion of the twisted structure TWC (i.e., including conductors CON-1961T'' and CON-DE) effectively reverses the relative positions of the portions of the conductors carrying current in each direction, thus helping to average out corresponding effects and couplings, etc. (e.g., resulting in at least partial self-cancellation of the effects / contributions, etc.).

[0177] For current flowing in the illustrated direction through field generating coil 1961, via VIA-B is coupled to one end of field generating coil section 1961T, which in turn couples the other end of field generating coil section 1961T to via VIA-C. Via VIA-C is coupled to one end of field generating coil section 1961B, which in turn couples the other end of field generating coil section 1961B to via VIA-A. Via VIA-A corresponds to the current path through that series of components. More specifically, in the orientation shown in FIG. 23 , a portion of the current from conductor CON-1961T″ flows upward through the top of via VIA-B, counterclockwise through field generating coil section 1961T, downward through via VIA-C to flow counterclockwise through field generating coil section 1961B, then upward through the bottom of via VIA-A and out through conductor CON-1961B′.

[0178] Additionally, as discussed above with respect to FIGS. 21 and 22, for current flowing in the illustrated direction through parallel capacitor structure PCC (i.e., comprising capacitors C2U and C2L), capacitor C2U is coupled between the tops of vias VIA-A and VIA-B, and capacitor C2L is coupled between the bottoms of vias VIA-A and VIA-B, which correspond to the current path through these series of components. More specifically, a portion of the current from conductor CON-1961T″ flows upward through the top of via VIA-B, through capacitor C2U, downward through the top of via VIA-A, and out through conductor CON-1961B′. And, a portion of the current from conductor CON-1961T″ flows downward through the bottom of via VIA-B, through capacitor C2L, upward through the bottom of via VIA-A, and upward through conductor CON-1961B′. As mentioned above, capacitor C2U may be part of upper branch UB and capacitor C2L may be part of lower branch LB of field generating coil coupling and crosstalk cancellation structure CCRC-5.

[0179] In FIG. 24 , field-generating coil coupling and crosstalk cancellation structure CCRC-6 couples signal processing and control circuitry (e.g., signal processing and control circuitry 480, such as in FIG. 4 ) to field-generating coil 1961 (i.e., comprising field-generating coil sections 1961B and 1961T). In the example of FIG. 24 , field-generating coil coupling and crosstalk cancellation structure CCRC-6 comprises vias VIA-A1, VIA-A2, VIA-B1, VIA-B2, and VIA-C, capacitor C2, conductive shield CSD, and conductors CON-1961T, CON-1961B, CON-A2B1, and CON-A2B2. As explained in more detail below, the primary difference from FIG. 22 is that a different current flow structure is utilized in FIG. 24 (e.g., comprising conductor CON-A2B2 as lower current branch LCB, so that certain similar balancing current effects can be achieved, but a lower capacitor such as capacitor C2L is not utilized).

[0180] In Figure 24, similar to the configurations of Figures 22 and 23, conductors CON-1961T and CON-1961B couple back to signal processing and control circuitry (e.g., as part of conductive coupling portion CCP-6) as part of field-generating coil coupling and crosstalk cancellation arrangement CCRC-6, such that conductive shielding CSD is shown in close proximity to (e.g., covering) at least a portion of conductors CON-1961B and CON-1961T. In particular, conductive shielding CSD is shown in close proximity to (e.g., covering) at least a portion of conductors CON-1961B and CON-1961T that are in close proximity to field-generating coil 1961 (i.e., including field-generating coil portions 1961B and 1961T).

[0181] The following describes current paths (e.g., AC currents may flow in both directions, but are described in terms of a single direction for simplicity of the following examples) for currents flowing between signal processing and control circuitry (e.g., signal processing and control circuitry 480 of FIG. 4 ) and field-generating coil 1961 (i.e., including field-generating coil portions 1961B and 1961T). Arrows are provided in FIG. 24 to indicate the direction of current flow, along with the following descriptions. For currents flowing in the illustrated direction from the signal processing and control circuitry to field-generating coil 1961, conductor CON-1961B is coupled to via VIA-A1, and thus corresponds to the current path through these components. For currents flowing along the return path in the illustrated direction from field-generating coil 1961 to the signal processing and control circuitry, via VIA-B2 is coupled to conductor CON-1961T, and thus corresponds to the current path through these components.

[0182] 24, the field-generating coil coupling and crosstalk cancellation structure CCRC-6 includes a three-current branch structure TCB. In various embodiments, the three-current branch structure TCB can have a lemniscate shape or a shape that can be considered to correspond to the English "figure eight" shape. The three-current branch structure TCB includes a middle current branch MCB (e.g., including conductor CON-A2B1) having a current flow in a first direction, and upper and lower current branches UCB and LCB (e.g., including capacitor C2 and conductor CON-A2B2, respectively) coupled to the middle current branch MCB and having a current flow in a second direction generally opposite the first direction. In various embodiments, the upper and lower current branches UCB and LCB may be disposed approximately equally spaced above and below the middle current branch MCB and / or the field-generating coil plane FGCP, respectively.

[0183] For current flowing in the illustrated direction through the three-current branch component TCB, capacitor C2 (e.g., as the upper current branch UCB) is coupled between the top of vias VIA-A1 and VIA-B1, conductor CON-A2B1 (e.g., as the middle current branch MCB) is coupled between the middle of vias VIA-B1 and VIA-A2, and conductor CON-A2B2 (e.g., as the lower current branch LCB) is coupled between the bottom of vias VIA-A2 and VIA-B2, thus corresponding to a current path through that series of components. In various embodiments, with reference to current flowing in the illustrated direction, the current flow through conductor CON-A2B1 (e.g., as the middle current branch MCB) may be referred to as being in a first direction, and the current flow through capacitor C2 (e.g., as the upper current branch UCB) and conductor CON-A2B2 (e.g., as the lower current branch LCB) may be referred to as being in a second direction (e.g., the second direction may be substantially opposite to the first direction). More specifically, in the direction shown in FIG. 24, a portion of the current from conductor CON-1961B flows upward through the top of via VIA-A1, flows through capacitor C2 (e.g., in the second direction), flows downward through the top of via VIA-B1, flows through conductor CON-A2B1 (e.g., in the first direction), flows downward through the bottom of via VIA-A2, flows through conductor CON-A2B2 (e.g., in the second direction), flows upward through the bottom of via VIA-B2, and exits through conductor CON-1961T.

[0184] Similar to the discussion of the parallel capacitor configuration PCC, if conductor CON-A2B2 (e.g., as the lower current branch LCB) were omitted from the three-current branch configuration TCB of FIG. 24, current would flow through capacitor C2 above the field-generating coil plane FGCP without a corresponding current flowing below the field-generating coil plane FGCP. Such a configuration could result in a relatively unbalanced effect (e.g., in the magnetic field) relative to the field-generating coil plane FGCP and thus crosstalk errors (e.g., from crosstalk corresponding to the effect of current through capacitor C2) in the signal generated by the axial detection coil. By including conductor CON-A2B2 (e.g., as the lower current branch LCB) as part of the three-current branch configuration TCB, similar currents can be caused to occur at approximately equal distances and in similar relative positions (e.g., having similar or identical X and Y coordinates) above and below the field-generating coil plane FGCP. Such a balanced configuration (e.g., relative to the field generating coil plane FGCP) helps to reduce any corresponding errors (e.g., crosstalk errors) that might otherwise occur in the determined position signal (e.g., resulting from signals generated by axial detection coils).

[0185] In various embodiments, the lower current branch LCB and the upper current branch UCB may be referred to, or alternatively referred to, as the upper branch UB and the lower branch LB, respectively, of the field-generating coil coupling and crosstalk cancellation configuration CCRC-6. In various embodiments, the aforementioned lower branch LB and upper branch UB (e.g., the field-generating coil coupling and crosstalk cancellation configurations of FIGS. 21-23 ) may be referred to, or alternatively referred to, as the upper current branch UCB and the lower current branch LCB, respectively, of the respective field-generating coil coupling and crosstalk cancellation configurations. In all of the described field-generating coil coupling and crosstalk cancellation configurations of FIGS. 21-24 , similar currents may be made to occur at approximately equal distances above and below the FGCP in the field-generating coil plane and at similar relative X and Y coordinate locations (e.g., having similar or identical X, Y coordinates) (so that, for example, such a balanced configuration may help to reduce potential crosstalk errors, etc.).

[0186] For current flowing in the illustrated direction through field-generating coil 1961, via VIA-A1 is coupled to one end of field-generating coil section 1961B, which in turn couples the other end of field-generating coil section 1961B to via VIA-C. Via VIA-C is coupled to one end of field-generating coil section 1961T, which in turn couples the other end of field-generating coil section 1961T to via VIA-B1. Via VIA-B1 is coupled by the lower portion of three-current branch structure TCB (e.g., including conductors CON-A2B1 and CON-A2B2) to via VIA-B2, which corresponds to the current path through that series of components. More specifically, in the orientation shown in FIG. 24, a portion of the current from conductor CON-1961B flows downward through the bottom of via VIA-A1, flows clockwise through field generating coil section 1961B, flows upward through via VIA-C so as to flow clockwise through field generating coil section 1961T, then flows downward through the top of via VIA-B1, flows through conductor CON-A2B1, flows downward through the bottom of via VIA-A2, flows through conductor CON-A2B2, flows upward through the bottom of via VIA-B2, and exits through conductor CON-1961T.

[0187] Although Figures 19-24 have generally been described with respect to particular configurations shown in particular figures (e.g., Figures 3 and 4), the techniques described herein for compensating for and reducing / addressing crosstalk errors can be used in other embodiments, such as the embodiments described above with respect to Figures 5 and 6, with respect to Figures 9A, 9B and 10, and with respect to Figures 12B and 13A.

[0188] In some embodiments, a scanning probe comprises a stylus suspension, a stylus position detection arrangement, signal processing and control circuitry, and a field generating coil coupling and crosstalk cancellation arrangement, the stylus suspension comprising a stylus coupling portion attached to a frame of the scanning probe and configured to be rigidly coupled to a stylus, and a stylus movement mechanism configured to enable axial movement of the stylus coupling portion along an axial direction and rotational movement of the stylus coupling portion about a center of rotation.

[0189] The stylus position detector is arranged along a central axis parallel to the axial direction and nominally aligned with the center of rotation and is based on an inductive detection principle, and comprises a field generating coil arrangement comprising at least one field generating coil, an upper axial detector coil arrangement (TASCC) comprising at least one upper axial detector coil, a lower axial detector coil arrangement (BASCC) comprising at least one lower axial detector coil, N upper rotation detector coils (TRSC), and N lower rotation detector coils (BRSC), where N is an integer greater than 3.

[0190] The disruptor arrangement provides a disruptor region and includes a conductive disruptor element disposed along a central axis within the disruptor movement volume. The disruptor element is coupled to the stylus suspension by a coupling arrangement and moves within the disruptor movement volume relative to an undeflected position in response to deflection of the stylus suspension. The disruptor element can be described as moving through an operational range of movement + / -Rz along the axial direction in response to axial movement and moving through respective operational ranges of movement + / -Rx and + / -Ry along orthogonal X and Y directions generally perpendicular to the axial direction in response to rotational movement. The field-generating coil arrangement generates a varying magnetic field generally along the axial direction within the disruptor movement volume in response to a coil drive signal.

[0191] The signal processing and control circuitry is operatively connected to the coils of the stylus position detection section to provide coil drive signals, and is configured to input signals from the receive coil section comprising respective signal components provided by the respective rotational and axial detection coils (i.e., the upper axial detection coil, the lower axial detection coil, the upper rotational detection coil, and the lower rotational detection coil), and is further configured to output signals indicative of the axial and rotational positions of at least one of the disruptor element or the stylus relative to the frame of the scanning probe.

[0192] The field-generating coil coupling and crosstalk cancellation arrangement is configured to couple the signal processing and control circuitry to the at least one field-generating coil for providing a coil drive signal and to reduce crosstalk that would otherwise occur if the at least one field-generating coil were directly connected to the signal processing and control circuitry without the field-generating coil coupling and crosstalk cancellation arrangement.

[0193] In some embodiments, the field-generating coil coupling and crosstalk cancellation structure has a first upper branch and a first lower branch. In some such embodiments, at least one field-generating coil comprises a first field-generating coil defining a first field-generating coil plane orthogonal to the central axis and passing through the first field-generating coil, such that the first upper branch and the first lower branch of the field-generating coil coupling and crosstalk cancellation structure are disposed above and below the first field-generating coil plane, respectively. In some such embodiments, the first upper branch and the first lower branch are at least one of symmetrical with respect to the first field-generating coil plane, part of a mirror current distribution structure, configured to carry similar currents at approximately equal distances and similar relative X and Y coordinate positions above and below the first field-generating coil plane, respectively, or connected in parallel. In some such embodiments, the first upper branch comprises a first upper capacitor and the first lower branch comprises a first lower capacitor, and the first upper capacitor and the first lower capacitor are connected in parallel.

[0194] In some such embodiments, the at least one field-generating coil comprises a second field-generating coil defining a second field-generating coil plane orthogonal to the central axis and passing through the second field-generating coil, such that the first and second field-generating coils correspond to upper and lower field-generating coils, respectively, and the field-generating coil coupling and crosstalk cancellation arrangement comprises a second upper branch and a second lower branch disposed above and below the second field-generating coil plane, respectively. In some such embodiments, the first upper branch comprises a first upper capacitor and the first lower branch comprises a first lower capacitor, the first upper capacitor and the first lower capacitor being connected in parallel. Also, the second upper branch comprises a second upper capacitor and the second lower branch comprises a second lower capacitor, the second upper capacitor and the second lower capacitor being connected in parallel.

[0195] In some embodiments, the field-generating coil coupling and crosstalk cancellation configuration includes a mirrored current distribution configuration. In some such embodiments, the mirrored current distribution configuration includes a pair of capacitors connected in parallel. In some such configurations, the mirrored current distribution configuration includes a three-current branch configuration including a middle current branch having current flow in a first direction, and upper and lower current branches each coupled to the middle current branch and having current flow in a second direction generally opposite the first direction.

[0196] In some embodiments, the at least one field-generating coil comprises a first field-generating coil. In some such embodiments, the field-generating coil coupling and crosstalk cancellation arrangement comprises a first conductive coupling comprising a first conductor coupling the first field-generating coil to the signal processing and control circuitry, thereby providing a first twist arrangement that cancels the contribution of the first conductor.

[0197] In some such embodiments, the field-generating coil coupling and crosstalk cancellation arrangement comprises a first conductive coupling portion for coupling the first field-generating coil to the signal processing and control circuitry, whereby at least a portion of the first conductive coupling portion is proximate to the first field-generating coil, and a first conductive shield disposed proximate to the first field-generating coil and the first conductive coupling portion for shielding the first conductive coupling portion. In some such embodiments, the field-generating coil coupling and crosstalk cancellation arrangement further comprises a second conductive shield at a second position relative to the central axis, where the first conductive shield is at a first position relative to the central axis, and the first and second positions are symmetrical about the central axis.

[0198] In some embodiments, the method includes moving a scanning probe as disclosed herein along a surface of the workpiece, and generating three-dimensional position information based on an inductive detection signal generated by the scanning probe as the scanning probe moves along the surface of the workpiece.

[0199] In some embodiments, a system comprises a scanning probe as disclosed herein, a drive mechanism, and a mount configured to couple the scanning probe to the drive mechanism.

[0200] While preferred embodiments of the present disclosure have been illustrated and described, numerous variations on the illustrated and described arrangements of features and sequences of operations will be apparent to those skilled in the art based on this disclosure. Various alternatives can be used to implement the principles disclosed herein. Furthermore, the various embodiments described above can be combined to provide further embodiments. All U.S. patents and U.S. patent applications mentioned herein are incorporated herein by reference in their entirety. Aspects of the embodiments can be modified, employing concepts from the various patents and applications to provide further embodiments as needed.

[0201] These and other changes can be made to the embodiments in light of the above detailed description. Generally, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full range of equivalents to which such claims are entitled.

Claims

1. In a scanning probe for a coordinate measuring machine, a stylus coupling portion configured to be rigidly coupled to a stylus; a stylus movement mechanism configured to allow axial movement of the stylus coupling portion along an axial direction and rotational movement of the stylus coupling portion about a center of rotation; a stylus suspension coupled to a frame of the scanning probe comprising: a field generating coil arrangement comprising at least one field generating coil; an upper axial detection coil arrangement comprising at least one upper axial detection coil; a lower axial detection coil arrangement comprising at least one lower axial detection coil; N upper rotation detection coils and N lower rotation detection coils (N is an integer of at least 3); a disruptor arrangement providing a disruptor region and comprising a conductive disruptor element disposed along a central axis of a disruptor movement volume and coupled to said stylus suspension by a coupling arrangement; the disruptor element moves through an operational range of motion along the axial direction of + / -Rz in response to the axial translation and through respective operational ranges of motion along orthogonal X and Y directions orthogonal to the axial direction of + / -Rx and + / -Ry in response to the rotational translation, the disruptor element moves within the disruptor movement volume to an undeflected position in response to deflection of the stylus suspension, and the field generating coil arrangement generates a varying magnetic flux within the disruptor movement volume generally along the axial direction in response to coil drive signals, a stylus position detection portion disposed along the central axis that is parallel to the axial direction and nominally aligned with the center of rotation; a signal processing and control circuit operatively connected to the coils of the stylus position detector to provide the coil drive signal, the signal processing and control circuit being configured to input a signal comprising respective signal components provided by the upper axial detector coil, the lower axial detector coil, the upper rotational detector coil and the lower rotational detector coil, and to output a signal indicative of the axial and rotational position of at least one of the disruptor element or the stylus relative to the frame of the scanning probe; a field-generating coil coupling and crosstalk cancellation arrangement configured to couple the signal processing and control circuitry to the at least one field-generating coil and to reduce crosstalk that would otherwise occur if the at least one field-generating coil were connected directly to the signal processing and control circuitry without the field-generating coil coupling and crosstalk cancellation arrangement; the field generating coil coupling and crosstalk cancellation arrangement comprises a first upper leg and a first lower leg; the at least one field-generating coil comprises a first field-generating coil orthogonal to the central axis and defining a first field-generating coil plane, such that the first upper branch and the first lower branch of the field-generating coil coupling and crosstalk cancellation arrangement are disposed above and below, respectively, the first field-generating coil plane; The first upper branch and the first lower branch are symmetrical with respect to the plane of the first field-generating coil; is part of a mirrored current distribution arrangement comprising a plurality of parallel connected capacitors configured to pass similar currents above and below the plane of the first field generating coil; configured to pass similar currents above and below the plane of the first field-generating coil at approximately equal distances and similar relative X and Y coordinate locations, respectively; or are connected in parallel, A scanning probe characterized by being at least one of the above.

2. 2. The scanning probe of claim 1, A scanning probe, characterized in that the first upper branch includes a first upper capacitor, the first lower branch includes a first lower capacitor, and the first upper capacitor and the first lower capacitor are connected in parallel.

3. 2. The scanning probe of claim 1, the at least one field-generating coil comprises a second field-generating coil orthogonal to the central axis and defining a second field-generating coil plane, such that the first field-generating coil and the second field-generating coil correspond to an upper field-generating coil and a lower field-generating coil, respectively; and the field-generating coil coupling and crosstalk cancellation arrangement comprises second upper and second lower branches disposed above and below the second field-generating coil plane, respectively; The second upper branch and the second lower branch are symmetrical with respect to the plane of the second field-generating coil; is part of a mirrored current distribution arrangement comprising a plurality of parallel-connected capacitors configured to pass similar currents above and below the plane of the second field-generating coil; configured to pass similar currents above and below the plane of the second field-generating coil at approximately equal distances and similar relative X and Y coordinate locations, respectively; or are connected in parallel, A scanning probe characterized by being at least one of the above.

4. 4. The scanning probe of claim 3, the first upper branch includes a first upper capacitor, the first lower branch includes a first lower capacitor, and the first upper capacitor and the first lower capacitor are connected in parallel; A scanning probe, characterized in that the second upper branch includes a second upper capacitor, the second lower branch includes a second lower capacitor, and the second upper capacitor and the second lower capacitor are connected in parallel.

5. 2. The scanning probe of claim 1, 10. A scanning probe comprising: a field generating coil coupling and crosstalk cancellation arrangement; a mirror current distribution arrangement having a plurality of capacitors connected in parallel configured to pass similar currents above and below the plane of the first field generating coil;

6. 6. The scanning probe of claim 5, a scanning probe, characterized in that the mirror current distribution structure comprises a three-current branch structure including a middle current branch having a current flow in a first direction, and upper and lower current branches each having a capacitor composed of a plurality of capacitors, each coupled to the middle current branch, and having a current flow in a second direction generally opposite to the first direction.

7. 2. The scanning probe of claim 1, The at least one field generating coil comprises: a first field generating coil; and a field generating coil coupling and crosstalk cancellation arrangement; 10. The scanning probe of claim 9, wherein the field-generating coil coupling and crosstalk cancellation arrangement comprises a first conductive coupling comprising a first conductor coupling the first field-generating coil to the signal processing and control circuitry, and wherein a first twist arrangement is provided to cancel the contribution of the first conductor.

8. 2. The scanning probe of claim 1, The at least one field generating coil comprises: a first field generating coil; and the field generating coil coupling and crosstalk cancellation arrangement; The field generating coil coupling and crosstalk cancellation arrangement comprises: a first conductive coupling coupling the first field-generating coil to the signal processing and control circuitry; a first conductive shield disposed proximate the first field-generating coil and the first conductive coupling for shielding the first conductive coupling; A scanning probe comprising:

9. 9. The scanning probe of claim 8, the field-generating coil coupling and crosstalk cancellation arrangement further comprising a second conductive shield at a second position relative to the central axis, the first conductive shield at a first position relative to the central axis, and the first and second positions being symmetrical about the central axis.

10. moving a scanning probe along a surface of a workpiece; generating three-dimensional position information based on inductive detection signals generated by the scanning probe as it moves along the surface of the workpiece; A method comprising: The scanning probe a stylus coupling portion configured to be rigidly coupled to a stylus; a stylus movement mechanism configured to allow axial movement of the stylus coupling portion along an axial direction and rotational movement of the stylus coupling portion about a center of rotation; a stylus suspension coupled to a frame of the scanning probe comprising: a field generating coil arrangement comprising at least one field generating coil; an upper axial detection coil arrangement comprising at least one upper axial detection coil; a lower axial detection coil arrangement comprising at least one lower axial detection coil; N upper rotation detection coils and N lower rotation detection coils (N is an integer of at least 3); a disruptor arrangement providing a disruptor region and comprising a conductive disruptor element disposed along a central axis of a disruptor movement volume and coupled to said stylus suspension by a coupling arrangement; the disruptor element moves through an operational range of motion along the axial direction of + / -Rz in response to the axial translation and through respective operational ranges of motion along orthogonal X and Y directions orthogonal to the axial direction of + / -Rx and + / -Ry in response to the rotational translation, the disruptor element moves within the disruptor movement volume to an undeflected position in response to deflection of the stylus suspension, and the field generating coil arrangement generates a varying magnetic flux within the disruptor movement volume generally along the axial direction in response to coil drive signals, a stylus position detection portion disposed along the central axis that is parallel to the axial direction and nominally aligned with the center of rotation; a signal processing and control circuit operatively connected to the coils of the stylus position detector to provide the coil drive signal, the signal processing and control circuit being configured to input a signal comprising respective signal components provided by the upper axial detector coil, the lower axial detector coil, the upper rotational detector coil and the lower rotational detector coil, and to output a signal indicative of the axial and rotational position of at least one of the disruptor element or the stylus relative to the frame of the scanning probe; a field-generating coil coupling and crosstalk cancellation arrangement configured to couple the signal processing and control circuitry to the at least one field-generating coil to reduce crosstalk that would otherwise occur if the at least one field-generating coil were connected directly to the signal processing and control circuitry without the field-generating coil coupling and crosstalk cancellation arrangement; The field generating coil coupling and crosstalk cancellation arrangement comprises: a first upper branch and a first lower branch; the at least one field generating coil is a first field generating coil orthogonal to the central axis and defining a first field generating coil plane, the first upper branch and first lower branch of the field generating coil coupling and crosstalk cancellation arrangement being located above and below the first field generating coil plane, respectively; The first upper branch and the first lower branch are symmetrical with respect to the plane of the first field-generating coil; is part of a mirrored current distribution arrangement comprising a plurality of parallel connected capacitors configured to pass similar currents above and below the plane of the first field generating coil; configured to pass similar currents above and below the plane of the first field-generating coil at approximately equal distances and similar relative X and Y coordinate locations, respectively; or are connected in parallel, The method is characterized by being at least one of the following.

11. a scanning probe; A drive mechanism; a mount coupling the scanning probe to the drive mechanism, The scanning probe a stylus coupling portion configured to be rigidly coupled to a stylus; a stylus movement mechanism configured to allow axial movement of the stylus coupling portion along an axial direction and rotational movement of the stylus coupling portion about a center of rotation; a stylus suspension coupled to a frame of the scanning probe comprising: a field generating coil arrangement comprising at least one field generating coil; an upper axial detection coil arrangement comprising at least one upper axial detection coil; a lower axial detection coil arrangement comprising at least one lower axial detection coil; N upper rotation detection coils and N lower rotation detection coils (N is an integer of at least 3); a disruptor arrangement providing a disruptor region and comprising a conductive disruptor element disposed along a central axis of a disruptor movement volume and coupled to said stylus suspension by a coupling arrangement; the disruptor element moves through an operational range of motion along the axial direction of + / -Rz in response to the axial translation and through respective operational ranges of motion along orthogonal X and Y directions orthogonal to the axial direction of + / -Rx and + / -Ry in response to the rotational translation, the disruptor element moves within the disruptor movement volume to an undeflected position in response to deflection of the stylus suspension, and the field generating coil arrangement generates a varying magnetic flux within the disruptor movement volume generally along the axial direction in response to coil drive signals, a stylus position detection portion disposed along the central axis that is parallel to the axial direction and nominally aligned with the center of rotation; a signal processing and control circuit operatively connected to the coils of the stylus position detector to provide the coil drive signal, the signal processing and control circuit being configured to input a signal comprising respective signal components provided by the upper axial detector coil, the lower axial detector coil, the upper rotational detector coil and the lower rotational detector coil, and to output a signal indicative of the axial and rotational position of at least one of the disruptor element or the stylus relative to the frame of the scanning probe; a field-generating coil coupling and crosstalk cancellation arrangement that couples the signal processing and control circuitry to the at least one field-generating coil and that is configured to reduce crosstalk that would otherwise occur if the at least one field-generating coil were connected directly to the signal processing and control circuitry without the field-generating coil coupling and crosstalk cancellation arrangement; Equipped with The field generating coil coupling and crosstalk cancellation arrangement comprises: a first upper branch and a first lower branch; the at least one field generating coil is a first field generating coil orthogonal to the central axis and defining a first field generating coil plane, the first upper branch and first lower branch of the field generating coil coupling and crosstalk cancellation arrangement being located above and below the first field generating coil plane, respectively; The first upper branch and the first lower branch are symmetrical with respect to the plane of the first field-generating coil; is part of a mirrored current distribution arrangement comprising a plurality of parallel connected capacitors configured to pass similar currents above and below the plane of the first field generating coil; configured to pass similar currents above and below the plane of the first field-generating coil at approximately equal distances and similar relative X and Y coordinate locations, respectively; or are connected in parallel, A system characterized by being at least one of:

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