JP2019113542A - Winding of electromagnetic induction encoder, and scale configuration - Google Patents

Abstract

To provide a configuration of an encoder which provides an improved combination.SOLUTION: A detection unit includes first and second track magnetic field generating coil parts surrounding first and second internal regions respectively aligned with respect to first and second pattern tracks. The first and second track magnetic field generating coil parts have first and second expansion parts respectively extending in a measurement axis direction and connected to terminal ends extending in a Y-axis direction crossing the measurement axis. A detection unit 167 includes a detection element over the first and second internal regions in the Y-axis direction. A nominal Y-axis trace width dimension of the expansion part is at least 0.1 times the Y-axis width of the first and/or second internal regions. In various embodiments, a shielded terminal section is used for connecting the expansion part.SELECTED DRAWING: Figure 2

Description

This application is a continuation-in-part of US patent application Ser. No. 15 / 245,560, filed on Aug. 24, 2016, entitled "WINDING CONFIGURATION FOR INDUCTIVE POSITION ENCODER", the disclosure of which is incorporated herein by reference. Is incorporated herein by reference in its entirety.

  TECHNICAL FIELD The present disclosure relates to a measuring instrument, and more specifically to an electromagnetic induction encoder that can be used in a precision measuring instrument.

  Various encoder configurations may include various types of optical, capacitive, magnetic, inductive, movement and / or position transducers. These transducers use various geometric configurations of transmitters and receivers in the readhead to measure movement between the readhead and the scale. Magnetic and inductive transducers, although relatively robust to contamination, are not perfect.

  U.S. Pat. No. 5,958,015 describes an inductive transducer that can be used for high precision applications. U.S. Pat. Nos. 5,958,015 and 5,086,059 describe an electromagnetic induction incremental caliper and a linear scale that includes signal generation and processing circuitry. U.S. Pat. Nos. 5,677,898, 6,075,015 and 6,087,059 describe electromagnetic induction absolute calipers and electronic tape measures that use inductive transducers. U.S. Pat. No. 6,097,015 describes an inductive transducer that can be used for high precision applications, where a scale with two parallel halves and multiple sets of transmit and receive coils has a specific signal offset component. To reduce Such components, if not mitigated, can cause errors in the inductive transducer. As described in these patents, inductive transducers may be manufactured using printed circuit board technology and are less susceptible to contamination.

U.S. Pat. No. 6,011,389 U.S. Patent No. 5,973,494 U.S. Patent No. 6002250 U.S. Pat. No. 5,886,519. U.S. Pat. No. 5,841,274 U.S. Pat. No. 5,894,678 U.S. Pat. No. 7,906,958

  However, these systems may be limited in their ability to provide specific combinations of features desired by the user, such as, for example, a combination of small size, signal strength, high resolution, cost, misalignment and robustness against dirt etc. . It would be desirable to have an encoder configuration that provides an improved combination.

  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.

  An electronic encoder is provided that can be used to measure the relative position of the two elements along a measurement axis direction that coincides with the X axis direction. In various embodiments, the electronic encoder includes a scale, a detector, and a signal processor. The scale includes a signal modulation scale pattern that includes a first pattern track and a second pattern track that extend along the measurement axis and are arranged parallel to one another. Each pattern track has a track width dimension along the Y-axis direction perpendicular to the X-axis direction between its inner boundary closest to the other pattern track and its outer boundary farthest from the other pattern track . Each pattern track includes signal modulation elements arranged to provide spatially varying features that vary as a periodic function of position along the X-axis direction.

  The detector is mounted close to the pattern track and configured to move relative to the pattern track along the measurement axis direction. In various embodiments, the detection unit includes a magnetic field generating coil unit and a plurality of sensing elements.

  The magnetic field generating coil is fixed on the substrate and includes a first track magnetic field generating coil part and a second track magnetic field generating coil part. The first track magnetic field generating coil portion surrounds a first inner region aligned with the first pattern track, and a nominal first inner region length dimension along the X axis direction and a nominal first along the Y axis direction. An internal region width dimension, and responsive to the coil drive signal, generates a first flux change in the first internal region. The second track magnetic field generating coil portion surrounds a second inner region aligned with the second pattern track, and a nominal second inner region length dimension along the X axis direction and a nominal second along the Y axis direction. A second flux change is generated in the second interior region in response to the coil drive signal.

  The plurality of sensing elements are disposed along the X-axis direction and fixed on the substrate. Each of the sensing elements has a nominal sensing element width dimension along the Y-axis direction across the first interior area and the second interior area, and a plurality of sensing elements are provided by adjacent signal modulation elements of the scale pattern To provide a detection signal responsive to the local effects on flux changes.

  The signal processor may be operatively connected to the detector to provide a coil drive signal, and determines the relative position of the detector and the scale pattern based on the detection signal input from the detector. .

  In various embodiments, the magnetic field generating coil portion includes an input portion and an extension portion. The extensions include a first track inner extension and a first track outer extension, a second track inner extension and a second track outer extension, and an associated end. The input unit includes at least two connection units for connecting the coil drive signal from the signal processing unit to the magnetic field generating coil unit. Each of the first track inner extension and the first track outer extension extends along the X-axis direction adjacent to the first inner region. The first track inner extension is positioned adjacent to the first track inner boundary, and the first track outer extension is positioned adjacent to the first track outer boundary. Each of the first track inner extension and the first track outer extension has a nominal first track field generating trace width dimension (which may be the same or different) along the Y-axis direction. Each of the second track inner extension and the second track outer extension extends along the X-axis direction adjacent to the second inner region. A second track inner extension is positioned adjacent to the second track inner boundary, and a second track outer extension is positioned adjacent to the second track outer boundary. Each of the second track inward extension and the second track outward extension has a nominal second track magnetic field generating trace width dimension (which may be the same or different) along the Y-axis direction. In various embodiments, at least half or more of the nominal sensing element width dimension is included between the first track outer extension and the second track outer extension, and the magnetic field generating coil portion generates each nominal first track magnetic field generation Each nominal second track field generation trace width dimension is at least 0.1 times the nominal second inner region width dimension such that the trace width dimension is at least 0.1 times the nominal first inner region width dimension Configured as.

  In some embodiments, each nominal first track field generation trace width dimension is at least 0.15, at least 0.25 times, or at least 0.5 times a nominal first inner region width dimension, The nominal second track field generation trace width dimension is at least 0.15 times, at least 0.25 times, or at least 0.5 times the nominal second inner region width dimension. In some embodiments, the magnetic field generating coil sections are defined with respective nominal first track magnetic field generation trace width dimensions and respective nominal second track magnetic field generation trace width dimensions corresponding to detection signals generated in response to flux changes. It may be configured to be at least twenty-five times the skin depth of the extension at the nominal operating frequency.

  In various embodiments, the first pattern track and the second pattern track are respectively arranged in the first pattern track and the second pattern track according to the same spatial period or wavelength W along the X-axis direction It contains the same type of signal modulation element. The signal modulation elements in the second pattern track are offset along the measurement axis direction by a nominal scale track offset of about W / 2 relative to the signal modulation elements in the first pattern track. In some of such embodiments, the magnetic field generating coil portion generates a first track flux change having a first polarity in the first inner region, and generates a first polarity and a second polarity in the second inner region. Is configured to generate a second track flux change having an opposite second polarity, the plurality of sensing elements including flux sensing loops formed by conductive traces formed on the printed circuit board, each At least half or more of the magnetic flux detection loops provide the same detection loop polarity in the first inner region and the second inner region along the Y-axis direction over the first inner region and the second inner region. In another embodiment of such an embodiment, the magnetic field generating coil portion generates a first track magnetic flux change having a first polarity in the first inner region, and the first magnetic field generating coil portion in the second inner region. The plurality of sensing elements are configured to generate a second track flux change having the same second polarity as the polarity, the plurality of sensing elements including flux sensing loops formed by conductive traces formed on the printed circuit board, each being At least half or more of the magnetic flux detection loops provide opposite detection loop polarities in the first inner region and the second inner region along the Y-axis direction and across the first inner region and the second inner region. As including crossing or twisting of conductive traces. In some such embodiments, for at least half or more of the magnetic flux sensing loops, crossing or twisting of the conductive traces may cause the first and second inner regions to avoid unwanted signal disturbances. And a second track inner extension between the first track and the second track.

FIG. 1 is an exploded isometric view of a hand tool type caliper using an electronic encoder that includes a detector and a scale. FIG. 2 is a plan view of a first exemplary embodiment of a detector usable in an electronic encoder. FIG. 3 is a plan view of a second exemplary embodiment of a detector usable in an electronic encoder. FIG. 4 is an isometric view of a first exemplary embodiment of the end of the magnetic field generating coil portion of the sensing portion. FIG. 5 is an isometric view showing a second exemplary embodiment of the end of the magnetic field generating coil portion of the sensing portion. FIG. 6 is a block diagram illustrating one exemplary implementation of the components of a measurement system that includes an electronic encoder. FIG. 7 is a plan view of a third exemplary implementation of a detector and compatible scale pattern that can be used in an electronic encoder. FIG. 8 is a plan view showing a fourth exemplary embodiment of a detector and compatible scale pattern that can be used in an electronic encoder.

  FIG. 1 is an exploded isometric view of a hand tool type caliper 100 including a scale member 102 having a substantially rectangular cross-section main scale including a scale 170 and a slider assembly 120. In various embodiments, scale 170 may extend along measurement axis direction MA (eg, corresponding to the X-axis direction), and may include signal modulation scale pattern 180. A cover layer 172 of known type (eg, 100 μm thick) may cover the scale 170. The jaws 108 and 110 near the first end of the scale member 102 and the movable jaws 116 and 118 on the slider assembly 120 are used to measure the dimensions of the object in a known manner. Slider assembly 120 may include a depth bar 126 that is received by end stop 154 into depth bar groove 152 below scale member 102. The depth bar measuring surface 128 can be extended into the hole to measure its depth. The cover 139 of the slider assembly 120 may include an on / off switch 134, a zero set switch 136, and a measurement results display 138. The base 140 of the slider assembly 120 includes a guide edge 142 in contact with the side edge 146 of the scale member 102, and the elastic pressure bar 148 is urged against the opposite edge of the scale member 102 by means of a screw 147 for measurement and Proper alignment for movement of the read head 164 relative to the scale 170 is ensured.

  A pickoff assembly 160 is provided on the base 140. The pickoff assembly 160 holds the read head portion 164. In the present embodiment, the read head unit 164 includes a detection unit 167 that includes a magnetic field generation coil unit and a detection element group (for example, a magnetic field generation and detection winding unit collectively) disposed along the measurement axis direction MA; It includes a substrate 162 on which a processing unit (for example, control circuit) 166 is mounted. A resilient seal 163 may be compressed between the cover 139 and the substrate 162 to prevent contamination of the circuitry and connections. The sensing portion 167 may be covered by an insulating coating.

  In one specific illustrative example, the detection unit 167 is disposed in parallel to the scale 170 and opposite to the scale 170, and the front surface of the detection unit 167 opposite to the scale 170 is in the depth (Z) direction , And may be spaced from the scale 170 (and / or the signal modulation scale pattern 180) by a gap of about 0.5 mm. The read head portion 164 and the scale 170 may be combined to form a transducer as part of an electronic encoder. In one embodiment, the transducer may be an eddy current transducer operating by generating a changing magnetic field. As described in more detail below, the changing magnetic field induces eddy currents known as eddy currents in some of the signal modulating elements of the signal modulation scale pattern 180 placed within the changing magnetic field. Of course, the caliper 100 shown in FIG. 1 is relatively optimized, such as small size, low power operation (eg for long battery life), high resolution and high precision measurement, low cost, robustness to dirt etc. It is one of a variety of applications that typically implement electronic encoders that have evolved over the years to provide a combination. Small improvements in any of these factors are highly desirable, but difficult to achieve, especially given the design constraints imposed to achieve commercial success in various applications. It is. The principles disclosed in the following description provide an improvement to some of these elements, particularly cost-effectively and compactly.

  FIG. 2 is a plan view of a first exemplary embodiment showing detector 167 and signal modulation scale pattern 180 usable in the electronic encoder shown in FIG. FIG. 2 may be considered partially representative and partially general. In the lower part of FIG. 2, the detection part 167 and the enlarged part of the signal modulation scale pattern 180 are shown. In FIG. 2, the various elements described below are represented by their shapes or outlines and are shown superimposed on one another to emphasize particular geometrical relationships. Of course, as will be apparent to the person skilled in the art based on the following description and / or as will be explained in more detail below with reference to FIG. The Z-axis position may be on different layers arranged in different planes so as to provide a gap and / or an insulating layer. It should be understood that, throughout the drawings of the present disclosure, the x-axis, y-axis and / or z-axis dimensions of one or more elements have been expanded for clarity.

  The illustrated portion of the signal modulation scale pattern 180 includes a signal modulation element SME shown in dashed outline, the signal modulation element being disposed on the scale 170 (shown in FIG. 1). In the embodiment shown in FIG. 2, the majority of the Y-direction end of the signal modulation element SME is hidden below the first extension EP1 and the second extension EP2. As seen in FIG. 1, of course, the signal modulation scale pattern 180 moves relative to the detector 167 during operation.

  In the example of FIG. 2, the signal modulation scale pattern 180 has a nominal scale pattern width dimension NSPWD along the Y-axis, which is perpendicular to the X-axis, and also (for example, corresponding to the X-axis direction) measurement axis direction MA The signal modulation elements SME are periodically arranged along the However, more generally, the signal modulation scale pattern 180 has spatial features whose pattern changes as a function of the position along the X-axis direction, whereby, according to a known method, the sensing element SEN of the sensing unit 167 If providing position-dependent detection signals (for example also called detection signal components in some embodiments) occurring at (for example SEN 14), various alternative spatial modulation patterns including individual elements or one or more continuous pattern elements May be included.

  In various embodiments, detector 167 is mounted proximate to signal modulation scale pattern 180 and configured to move relative to signal modulation scale pattern 180 along measurement axis direction MA. The sensing portion includes a magnetic field generating coil portion FGC and a plurality of sensing elements, which are used in various embodiments in combination with a wide variety of corresponding signal processing schemes, as will be appreciated by those skilled in the art. Various alternative configurations. FIG. 2 shows a single representative set of sensing elements SEN1 to SEN24. The sensing elements SEN1 to SEN24 comprise, in this particular embodiment, sensing loop elements (also referred to as sensing coil elements or sensing winding elements) connected in series. In this embodiment, the adjacent loop elements are conductors on the various layers of the PCB connected by feedthroughs according to known methods (eg as shown in FIG. 4) so as to have opposite winding polarity. Connected by the configuration of That is, if the first loop responds to a changing magnetic field with a positive polarity detection signal contribution, the adjacent loops react with a negative polarity detection signal contribution. In this particular embodiment, the sensing elements are summed their detection signals or signal contributions and the "total" detection signal is output to the signal processing unit (not shown) at the detection signal output connections SDS1 and SDS2. As connected in series. FIG. 2 shows a single set of sensing elements to avoid visual confusion, but of course, as will be appreciated by one skilled in the art, in some embodiments (eg providing orthogonal signals It is advantageous to configure the detection to provide one or more additional sets of sensing elements at different spatial phase positions. However, it should be understood that the configuration of the sensing element described herein is merely exemplary and not limiting. By way of example, individual sensing element loops are, in some embodiments, co-pending US patent application Ser. No. 15/199723, filed on Jun. 30, 2016 and assigned to the assignee of the present invention. Individual signals may be output to corresponding signal processing units as disclosed in U.S. Pat. More generally, in various embodiments, various known sensing element configurations are disclosed and claimed herein for use in combination with various known signal modulation scale patterns and signal processing schemes. It may be used in combination with the principle which concerns.

  Various sensing elements and magnetic field generating coil portions FGC may be fixed on a substrate (eg, substrate 162 in FIG. 1). Magnetic field generating coil portion FGC may be described as surrounding internal region INTA having a nominal coil region length dimension NCALD along the X-axis direction and a nominal coil region width dimension of about YSEP along the Y-axis direction . In various embodiments, the magnetic field generating coil unit FGC may include a single turn surrounding the inner area INTA. In operation, the magnetic field generating coil unit FGC generates a change in magnetic flux in the internal area INTA in response to the coil drive signal.

  In various embodiments, the magnetic field generating coil portion FGC comprises an input portion INP (implemented as disclosed for example with reference to FIG. 4 and / or FIG. 5), a first extension EP1 and a second extension EP1. An extension EP2 and an end EDP may be included. The input unit INP is connected to provide a coil driving signal from a signal processing unit (for example, the signal processing unit 166 in FIG. 1 or the signal processing unit 766 in FIG. 6) to the magnetic field generating coil unit FGC. It includes a part CP1 and a second connection part CP2. The first connection CP1 and the second connection CP2 may be connected to the signal processor via a printed circuit board feedthrough or the like, which in some embodiments refers to the termination EDP And may be shielded using principles similar to those disclosed below. Each of the first extension EP1 and the second extension EP2 extends along the X-axis direction adjacent to the side surface of the inner region INTA, and has a nominal magnetic field generation trace width dimension NGTWD along the Y-axis direction . In the illustrated embodiment, the nominal field generation trace width dimension NGTWD is the same for the first extension EP1 and the second extension EP2, but this is not essential in all embodiments. The termination EDP (for example realized as disclosed with reference to FIG. 4 and / or FIG. 5) corresponds to the nominal coil area width dimension YSEP between the first extension EP1 and the second extension EP2 A connection between the first extension EP1 and the second extension EP2 is provided near the end of the inner area INTA over the Y-axis distance interval. In various embodiments according to the principles disclosed herein, the magnetic field generating coil portion FGC uses a design ratio where each nominal magnetic field generating trace width dimension NGTWD is at least 0.1 times the nominal coil area width dimension YSEP. It is advantageous to be configured. In some embodiments, the magnetic field generating coil portion FGC is configured such that each nominal magnetic field generating trace width dimension NGTWD is at least 0.15 times, or at least 0.25 times, or at least 0. 5 times the nominal coil area width dimension YSEP. It may be configured to be fifty times. In some embodiments, the magnetic field generating coil portion FGC includes skins of the extensions EP1 and EP2 at defined nominal operating frequencies where each nominal magnetic field generating trace width dimension NGTWD corresponds to a detection signal generated in response to a change in magnetic flux. It may be configured to be at least 25 times the depth.

  The sensing elements SEN1 to SEN24 are disposed along the X-axis direction (for example, corresponding to the measurement axis direction MA), and fixed on a substrate (for example, the substrate 162 in FIG. 1). In the example of FIG. 2, each sensing element SEN has a nominal sensing element width dimension NSEWD along the Y-axis direction. In the example of FIG. 2, each sensing element SEN has a nominal sensing element width dimension NSEWD along the Y-axis direction. At least half or more of the nominal sensing element width dimension NSEWD is included in the nominal coil area width dimension YSEP along the Y-axis direction. The sensing element SEN provides a detection signal in response to local effects on the flux changes provided by the adjacent signal modulators of the signal modulation scale pattern 180 (for example one or more signal modulation elements SME) of the scale 170 Configured to Note that “a signal modulation unit adjacent to the signal modulation scale pattern 180” means a portion facing each sensing element SEN in the signal modulation scale pattern 180 of the scale 170, for example, the signal modulation element SME and signal modulation. A gap between elements SME (a portion where signal modulation element SME is not provided) corresponds to this. The signal processing unit (for example, the signal processing unit 166 in FIG. 1 or the signal processing unit 766 in FIG. 6) detects the positions of the plurality of detection elements SEN1 to SEN24 with respect to the scale 170 based on the detection signal input from the detection unit 167. It may be configured to make a decision. In general, the magnetic field generating coil section FGC and the sensing elements SEN1 to SEN24 etc may operate according to known principles (for example of an inductive encoder) as described in the respective patent documents described in the prior art documents.

  In various embodiments, the magnetic field generating coil portion FGC and the sensing element SEN are isolated from one another (eg, by being disposed in different layers of a printed circuit board, etc.). In one such embodiment, the nominal sensing element width dimension NSEWD of the at least one sensing element SEN is greater than the nominal coil area width dimension YSEP and the inner edge IE of the at least one extension EP1 or EP2 of the extension. Is advantageously extended by an amount defined as the overlap dimension OD. Furthermore, in various embodiments, the magnetic field generating coil portion FGC may be advantageously configured such that each nominal magnetic field generating trace width dimension NGTWD is greater than the corresponding overlap dimension OD. In various embodiments, the extensions EP1 and EP2 may be made on the first layer of the printed circuit board and the sensing element SEN differs from said first layer at least in the vicinity of the overlap dimension OD. The conductive loop may be included in one or more layers of the printed circuit board including the layers.

  In various embodiments, the substrate may include a printed circuit board, and the magnetic field generating coil portion FGC may include conductive traces (e.g., including extensions E1 and E2) fabricated on the printed circuit board. . In various embodiments, the sensing element SEN may include a magnetic flux sensing loop formed by conductive traces created on a printed circuit board. As described above with respect to FIG. 1, in various embodiments, the sensing portion 167 may be included in various types of measuring instruments (eg, calipers, micrometers, gauges, linear scales, etc.). For example, the detection unit 167 may be fixed to the slide member, and the signal modulation scale pattern 180 may be fixed to a beam member having a measurement axis coincident with the X-axis direction. In such a configuration, the slide member is movably attached to the beam member and is measured in a plane (Z-axis direction is orthogonal to the plane) extending along the X-axis direction and the Y-axis direction. It is movable along the axial direction MA.

  FIG. 3 is a plan view showing a second exemplary embodiment of the detection unit 367 that can be used as the detection unit 167 in the electronic encoder shown in FIG. 1 and the like. Detector 367 has features and components similar to detector 167 of FIG. 2, the design and operation of which are configured to meet the various design principles disclosed and claimed herein. ing. Specifically, the elements designated by the "primed (')" reference in FIG. 3 are similar to the elements with the corresponding similar "primed" reference in FIG. It may be understood that it operates similarly, unless explicitly stated below.

  The main difference between the embodiments of FIGS. 3 and 2 is that the detector 367 is such that the nominal scale pattern width dimension NSPWD is significantly larger than the nominal sensing element width dimension NSEWD 'and the other Y axis dimensions of the detector 367. Is a point narrower than the detection unit 167 along the Y-axis direction. For example, in one particular embodiment, the nominal sensing element width dimension NSEWD 'may be less than or equal to about 2/3 of the nominal scale pattern width dimension NSPWD. In various embodiments, such an arrangement may provide greater lateral offset tolerance for lateral movement of the detector 367 relative to the signal modulation scale pattern 180.

  Notwithstanding this difference, the other features of the detection unit 367 are similar to the other features of the detection unit 167. For example, each sensing element SEN 'may have a nominal sensing element width dimension NSEWD' along the Y-axis direction, and at least half or more of the nominal sensing element width dimension NSEWD 'may be a nominal coil area width along the Y-axis direction It is included in the dimension YSEP '. In various embodiments, the magnetic field generating coil portion FGC ′ comprises (for example realized as disclosed with reference to FIG. 4 and / or FIG. 5) the first extension EP1 ′ and the second extension EP2 And a termination EDP ', all of which may have a similar configuration to the corresponding elements of the detector 167. In some embodiments, the magnetic field generating coil portion FGC ′ has a nominal magnetic field generation trace width dimension NGTWD ′ of at least 0.10 times, or at least 0.15 times, or at least a nominal coil area width dimension YSEP ′. It may be configured to be 0.25 times or at least 0.50 times. Other features and / or design relationships may also be made similar to the features and / or design relationships described with reference to FIG. 2, as appropriate.

  With regard to the exemplary configuration of the detection units 167 and 367, it should be appreciated that some prior systems have a relatively narrow trace width and / or a relatively large internal area (eg, larger internal area INTA) in the magnetic field generating coil section. And / or nominal coil area width dimension YSEP). More specifically, in some prior systems, the associated detector elements generally have a relatively high inductance, such that the system has a Q value high enough to resonate for a relatively long period of time It was considered desirable to have This is because it was considered advantageous with respect to the signal processing and measurement methods used. In contrast, according to the principles disclosed herein, a wider trace width is used (e.g., for INTA and / or YSEP sacrifice for Y-axis dimension limitations across the detector imposed by the particular application). ). This results in a relatively small inductance and also a smaller overall impedance, whereas a larger amount of current can flow in a relatively short period of time (e.g. can generate a stronger signal) . Also, resonance can still be achieved for the desired length of time of measurement. As described above with respect to detectors 167 and 367, in various embodiments, each nominal magnetic field generation trace width dimension NGTWD is at least 0.10 times, or at least 0.15 times the nominal coil area width dimension YSEP, or , At least 0.25 times, or at least 0.50 times. In some embodiments, as some specific exemplary values, the nominal coil area width dimension YSEP may be about 2.0 mm, or 8.0 mm, or 10 mm, and each nominal magnetic field The generated trace width dimension NGTWD may be at least about 0.25 mm, or 0.50 mm, or 1.00 mm or more. These can be compared to the trace widths in some previous systems, which were about 0.10 mm. In some cases, such as the configuration disclosed in this specification, when the same drive signal is input to the magnetic field generating coil unit, the signal level of the same prior art configuration is 1.5 times or more, Also, in some cases, it has been found to achieve detection signal levels that are more than tripled.

  With regard to exemplary configurations such as detectors 167 and 367, in various embodiments, a sensing element SEN (eg, a loop or coil element surrounding an area as shown in FIGS. 2 and 3) is disclosed herein When configured in accordance with the maximum signal gain design principle, it may provide several advantages (eg, increased gain, etc.) over more conventional sensing elements. While the amount of the magnetic field reception area of the sensing element coincident with the magnetic field generating coil FGC or placed in the magnetic field generating coil portion FGC (for example, in the INTA) should be relatively maximized (for example, in the Y axis direction) The amount of magnetic field reception area of the sensing element that is outside the conductor forming the field generating coil portion FGC) should be relatively minimized. Of course, the sensing element SEN shown in FIGS. 2 and 3 exhibits an overlap dimension OD having the above design relationship consistent with this principle. For example, each nominal magnetic field generation trace width dimension NGTWD is made larger than the corresponding overlap dimension OD.

  FIG. 4 is an isometric view showing a first exemplary embodiment of a termination EDP of the field generation coil portion FGC, as disclosed herein and included within the detection portion 467 according to the principles of the claims; It is a "wire frame" figure. Of course, the elements of detection unit 467 may be designed and function in the same manner as the similarly referenced elements of detection unit 167 of FIG. 2 and may generally be understood by their similarity to them. Do. The detection unit 467 includes a magnetic field generation coil unit FGC and a plurality of detection elements SEN1 to SEN24 (representative detection elements SEN17 to SEN24 are shown in FIG. 4). The magnetic field generating coil unit FGC includes the first extension unit EP1 and the second extension unit EP2, and the end unit EDP, is fixed on a substrate (for example, the substrate 162 in FIG. 1), and surrounds the inner area INTA.

  In various embodiments, the magnetic field generating coil portion FGC and the sensing element SEN are arranged, for example, in various layers of the printed circuit board (the layer structure is not explicitly shown in FIG. 4). , Isolated from each other. In FIG. 4, it should be understood that the various labeled Z-coordinates are coincident with or identify the respective surfaces of the various printed circuit board (PCB) layers. However, other creation methods may be used. The signal modulation elements SME of the signal modulation scale pattern 180 are on the surface of the scale 170 (shown in FIG. 1) at the Z coordinate Zsme. Of course, the scale 170 is spaced apart from the printed circuit board (PCB) which carries the elements of the detector 467. In the embodiment shown in FIG. 4, the PCB has a front surface (eg, a front surface of the insulating coating) at Z coordinate Zfs. A motion gap exists between the Z coordinate Zsme of the scale element and the Z coordinate Zfs of the front surface. The extensions EP1 and EP2 may be made on the PCB layer surface with Z coordinate Zep and may be covered by an insulating coating. The sensing element SEN may include interconnected conductive loop portions on each PCB layer surface having Z coordinates ZseL1 and ZseL2. The conductive loop sections, as described above, use feedthroughs to connect the signal contributions of the sensing elements in series while the conductors cross each other, and provide each signal contribution polarity. It may be connected by

  Each of the first extension EP1 and the second extension EP2 extends along the X-axis direction, and extends in the signal modulation scale pattern 180 along the Z-axis direction which is perpendicular to the X-axis direction and the Y-axis direction. From the front surface of the PCB of the opposing detection unit 467, it is nominally located at the z-distance EPZD of the extension unit = (Zep-Zfs). As described above, the end portion EDP covers the distance between the first extension EP1 and the second extension EP2 in the Y-axis direction corresponding to the nominal coil area width dimension YSEP, and Near the ends, it comprises conductive paths which provide a connection between them. In the embodiment shown in FIG. 4, the termination EDP has a Z-coordinate Zses nominally located at the z-distance SESZD = (Zses-Zfs) of the shielded termination section from the front face of the PCB of the detector 467 And a shielded termination section SES on the surface of the corresponding PCB layer. The z-distance SESZD of the shielded end section is greater than the z-distance EPZD of the extension. The first connection CNP1 (eg PCB feedthrough) connects the first extension EP1 to the first end of the shielded termination section SES, and the second connection CNP2 (eg PCB feedthrough) , The second extension EP2 is connected to the second end of the shielded end section SES.

  In the embodiment shown in FIG. 4, the detection unit 467 further extends along the X-axis direction and the Y-axis direction, is nominally located on the surface of the corresponding PCB layer having the Z coordinate Zcsr, and also detects From the front of the PCB of part 467, the conductive shield area CSR (for example in FIG. 4 by a somewhat arbitrarily placed dashed "edge" line) located nominally at the z-distance SRZD = (Zcsr-Zfs) of the shield area Conductive planar area). In various embodiments, the z-distance SRZD of the shield region is less than the z-distance SESZD of the shielded termination section, and the conductive shielding region CSR comprises at least a portion of the shielded termination section SES and the sensing portion 467. Located between the front of the PCB. The conductive shield area CSR may include a portion of a large ground plane layer in the PCB of the detector 467 or, in some embodiments, an individual area. The conductive shield area CSR may include a clearance hole CH such that the first connection CNP1 and the second connection CNP2 (eg, PCB feedthrough) are separated or insulated from the conductive shield area CSR.

  Generally, the magnetic field component generated by the previously known configuration of the end of the magnetic field generating coil (for example, the end extending along the Y-axis direction) is the detection signal of the sensing element closest to the end An error component (so-called "end effect") is generated. Attempts have been made to mitigate this termination effect by using a "tapered termination configuration" in the detection section and / or by moving the termination far from the termination sensing element. However, these approaches undesirably reduce the signal strength, increase the x-axis dimension of the detector, or both. In contrast, the shield configuration tends to reduce the magnetic field components generated by the termination and / or to prevent it from reaching the signal modulation element SEM. Thus, the magnetic field component coupled to the closest sensing element is smaller and / or substantially constant regardless of the scale position, thus substantially reducing any termination effects.

  As mentioned above, in various embodiments the extensions EP1 and EP2 may be made on the first layer of the printed circuit board and the shielded termination section SES is the second layer of the printed circuit board It may be made on top, and the conductive shielding area CSR is made on the layer of the circuit board closer to the front face of the detection part (e.g. the front face of the PCB of the detection part) than the second layer of the printed circuit board. In one such embodiment, the conductive shield area CSR may be created on a layer of the printed circuit board disposed between the first layer and the second layer. In such a configuration, the conductive shield region CSR may include at least a portion of a ground plane layer of the printed circuit board, the ground plane layer being disposed between the first layer and the second layer . In one embodiment, the connection between the extension EP1 or EP2 and the shielded end section SES (for example as part of the first connection CNP1 or the second connection CNP2) is in the Z-axis direction. May include printed circuit board feedthroughs extending along the In one such configuration, the conductive shield area CSR may be created on a layer of the printed circuit board disposed between the first layer and the second layer, and the printed circuit board feedthrough is , Through the opening created in the conductive shield region CSR.

  FIG. 5 shows a second exemplary embodiment of the end EDP ′ ′ of the magnetic field generating coil part FGC ′ ′ included in the detection part 567 according to the principles disclosed and claimed herein. Fig. 2 is a "wire frame" view of the corner view. Of course, the elements of detection unit 567 may be designed and operated in the same manner as elements with the same reference numerals of detection unit 167 of FIG. 2 and / or detection unit 467 of FIG. It should be understood by the similarity of

  In FIG. 5, as in FIG. 4, various labeled Z-coordinates are to be understood as coinciding with or identifying each surface of various printed circuit board (PCB) layers. However, other creation methods may be used. Element SME of signal modulation scale pattern 180 is on the surface of scale 170 (shown in FIG. 1) at Z coordinate Zsme. The detection unit 567 has a front surface at the Z coordinate Zfs (for example, the front surface of the insulating coating on the PCB of the detection unit 567). A motion gap exists between the Z coordinate Zsme of the scale element and the Z coordinate Zfs of the front surface. The extensions EP1 and EP2 may be made on the surface of the PCB layer having the Z coordinate Zep and may be covered by an insulating coating. The sensing element SEN may include interconnected conductive loop portions on each surface of the PCB layer having Z coordinates ZseL1 and ZseL2, which are connected as described above with reference to the sensing portion 467. Be done.

  The first extension part EP1 and the second extension part EP2 are nominally located at the z-distance EPZD = (Zep−Zfs) of the extension part from the front surface facing the signal modulation scale pattern 180 of the detection part 567. . As in the detection unit 467, the end EDP ′ ′ extends over the distance between the first extension EP1 and the second extension EP2 in the Y-axis direction corresponding to the nominal coil area width dimension YSEP. Near the end of the inner area INTA, it comprises a conductive path providing a connection between them. In the embodiment shown in FIG. 5, the termination EDP " comprises a shielded termination section SES " lying on the surface of the corresponding PCB layer having the Z coordinate Zses ". The end section SES ′ ′ is nominally located from the front face of the detection unit 567 at the z-distance SESZD ′ ′ = (Zses ′ ′ − Zfs) of the shielded end section. The z-distance SESZD '' of the shielded end section is greater than the z-distance EPZD of the extension. A first connection CNP1 (for example comprising PCB feedthrough CNP1A and conductive trace CNP1B) connects the first extension EP1 to the first end of the shielded termination section SES (for example PCB feedthrough A second connection CNP2 (comprising CNP2A and conductive trace CNP2B) connects the second extension EP2 to the second end of the shielded termination section SES.

  In the embodiment shown in FIG. 5, the detection portion 567 further includes a conductive shield area CSR '' (e.g., a conductive planar area represented by a dashed border in FIG. 5). The conductive shield region CSR ′ ′ extends along the X-axis and Y-axis directions and is nominally located on the surface of the corresponding PCB layer having the Z coordinate Zcsr ′ ′ From the front, it is nominally located at the z-distance SRZD '' = (Zcsr ''-Zfs) of the shield area. In various embodiments, the z-distance SRZD ′ ′ of the shielding region is smaller than the z-distance SESZD ′ ′ of the shielded termination section, and the conductive shielding region CSR ′ ′ is at least at least partially shielded. It is disposed between a portion and the front surface of the PCB of the detection unit 567. For the embodiment shown in FIG. 5, it should be appreciated that in some implementations, the shield region CSR ′ ′ may be disposed on the same surface as the extensions EP1 and EP2 as required (ie, necessary Depending on: Zcsr '' = Zep and EPZD = SRZD ''). Furthermore, in one such embodiment, optionally the shielded termination section SES '' and the conductive traces CNP1B and CNP2B may be arranged on the same surface as used for the sensing element SEN (That is, if necessary, Zses ′ ′ = ZseL1 or Zses ′ ′ = ZseL2, etc.). In such an embodiment, the PCB of detector 567 may include fewer layers and / or may be thinner along the Z-axis direction than detector 467. In any case, the shielded configuration of the termination EDP '' in the detection unit 567 mitigates termination effects in a manner similar to that described above with reference to the termination EDP in the detection unit 467.

  With regard to the above exemplary detectors 467 and 567, it is understood that the conductive shield region CSR (CSR ′ ′) is different from the position of the layer of the extension portions EP1 and EP2 of the magnetic field generating coil portion FGC (eg different PCB layers Effect (e.g. associated with a flux change) of the shielded termination section SES on the sensing element SEN based at least in part on the relative layer position of the shielded termination section SES disposed on Can be reduced. Such a configuration allows the utilization of the conductive shielding region CSR (CSR '') and allows the magnetic field generating coil portion FGC to have a shorter overall X-axis dimension (for example, the end portion EDP , And need not be placed far away from the sensing element SEN to avoid affecting the detection signal generated in response to magnetic flux changes etc.).

  FIG. 6 is a block diagram illustrating one exemplary implementation of the components of measurement system 700 including electronic encoder 710. Of course, some numbered components 7XX in FIG. 6 correspond to and / or similar operations to similarly numbered components 1XX in FIG. 1 unless otherwise specified. Have. Electronic encoder 710 includes signal processing portion 766, scale 770 and detector portion 767 which when combined form a transducer. In various embodiments, detector 767 may include any of the configurations described with respect to FIGS. 2-6 or other configurations. The measurement system 700 further includes a user interface such as a display 738 and switches 734, 736 operable by the user, and may additionally include a power supply 765. In various implementations, an external data interface 732 may be included. All of these elements are coupled to signal processing unit 766 (or signal processing and control circuitry) which may be embodied as a signal processor. The signal processing unit 766 determines the position of the detection element of the detection unit 767 with respect to the scale 770 based on the detection signal input from the detection unit 767.

  In various embodiments, the signal processor 766 of FIG. 6 (and / or the signal processor 166 of FIG. 1) performs one or more processors executing software to perform the functions described herein. It may contain or consist of them. The processor includes a programmable general purpose or special purpose microprocessor, a programmable controller, an application specific integrated circuit (ASIC), a programmable logic device (PLD), etc. or a combination of such devices. The software may be stored in memory, such as random access memory (RAM), read only memory (ROM), flash memory, etc., or a combination of such components. The software may further be stored on one or more storage devices, such as an optical based disk, a flash memory device or any other type of non-volatile storage medium for storing data. The software may include one or more program modules including routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In a distributed computing environment, the functionality of the program modules may be combined, distributed across multiple computer systems or devices, and accessed via wired or wirelessly configured service calls.

  FIG. 7 is a plan view showing a third exemplary embodiment of the detection unit 767 and the compatible scale pattern 780 which can be used as the detection unit 167 and the scale pattern 180 in the electronic encoder shown in FIG. 1 etc. is there. The detector 767 has similar features and components as the detector 167 of FIG. 2 and its design and operation are configured to meet the various design principles disclosed herein and claimed. ing. Specifically, reference symbols or labels in FIG. 7 that are the same as or the same as reference symbols or labels in FIG. 2 or other drawings in the present specification (for example, suffixes with the same “XX” as in 7XX and 2XX) Elements designated by may designate similar elements and may be understood to operate similarly, unless indicated otherwise below. Therefore, only important differences between the detection unit 767 and the scale pattern 780 will be described below. Detector 767 and compatible scale pattern 780 provide an additional advantage in that they provide more robust signal accuracy and / or signal strength as compared to the above embodiments, as described in more detail below.

  The main difference between the embodiments of FIGS. 7 and 2 is that the scale pattern 780 includes a first pattern track FPT and a second pattern track SPT arranged parallel to one another. The first pattern track FPT is a nominal first along the Y-axis direction between the first track inner boundary FTIB closest to the other pattern track and the first track outer boundary FTEB farthest from the other pattern track It has one pattern track width dimension FPTWD. The second pattern track SPT is a nominally first along the Y-axis between the second track inner boundary STIB closest to the other pattern track and the second track outer boundary STEB farthest from the other pattern track It has a two-pattern track width dimension SPTWD. Each of the first pattern track FPT and the second pattern track SPT includes a signal modulation element SME arranged to provide a spatially varying feature that varies as a periodic function of position along the X-axis direction.

  Another major difference is that the detection unit 767 is configured for compatible operation with the scale pattern 780. The detection unit 767 includes a magnetic field generation coil unit FGC, and the magnetic field generation coil unit FGC may be fixed on the substrate, and the first track magnetic field generation coil unit FTFGCP and the second track magnetic field generation coil unit STFGCP including. The magnetic field generating coil unit FGC may include an input unit INP that includes at least two connections (eg, CP1 and CP2) that connect the coil drive signal from the signal processing unit to provide the magnetic field generating coil unit FGC. In the magnetic field generating coil part FGC, the first track magnetic field generating coil part FTFGCP surrounds the first inner area FINTA aligned with the first pattern track FPT, and the nominal first inner area length along the X-axis direction It has a dimension FIALD and a nominal first inner region width dimension YSEP1 along the Y-axis direction to generate a first flux change in the first inner region FINTA in response to the coil drive signal. Similarly, the second track magnetic field generation coil unit STFGCP surrounds the second inner area SINTA aligned with the second pattern track SPT, and has a nominal second inner area length dimension SIALD along the X-axis direction, A nominal second inner region width dimension YSEP2 is provided along the Y-axis direction, and a second magnetic flux change is generated in the second inner region SINTA in response to the coil drive signal.

  The detection unit 767 further includes a plurality of detection elements SEN (for example, SEN1, SEN14) disposed along the X-axis direction and fixed on the substrate. Each sensing element SEN has a nominal sensing element width dimension NSEWD along the Y-axis direction across the first inner area FINTA and the second inner area SINTA. The plurality of sensing elements are configured to provide a detector signal responsive to local effects on the flux changes provided by the adjacent signal modulation elements SME of the scale pattern 780. In various embodiments, the plurality of sensing elements SEN include magnetic flux sensing loops formed by conductive traces and feedthroughs made on a printed circuit board. In various embodiments (eg, as shown in FIG. 7), to provide a first sensing loop polarity (eg, responsive to a flux change of a first polarity to generate a current in a first direction) The magnetic flux sensing loop being configured has a first sensing loop polarity along the X-axis direction (e.g. responsive to a flux change of opposite polarity to the first polarity to produce current in the second direction) Interleaved with a flux sensing loop configured to provide an opposite second sensing loop polarity. A signal processor may be operatively connected to the detector to provide a coil drive signal, and from the illustrated sensing element SEN of the detector 767 (and according to known principles according to known methods) The relative position of the detector and the scale pattern is determined on the basis of the detection signal input from another sensing element SEN (not shown) provided to the phase position.

  As shown in FIG. 7, the magnetic field generating coil unit FGC and the sensing element SEN are advantageously configured in accordance with the principles already disclosed herein. The magnetic field generating coil portion FGC may include one or more of the illustrated feedthroughs to provide a shield configuration for one or more of the terminations EDP. Of course, the illustrated feedthroughs which may or may not be necessary in certain embodiments may be omitted.

  In the embodiment shown in FIG. 7, each of the first track inner extension FTIEP and the first track outer extension FTOEP extends along the X-axis direction adjacent to the first inner area FINTA. The first track inner extension FTIEP is positioned adjacent to the first track inner boundary FTIB, and the first track outer extension FTOEP is positioned adjacent to the first track outer boundary FTEB. The first track inner extension FTIEP has a nominal first track inner magnetic field generating trace width dimension NFTIGTWD along the Y-axis direction. The first track outer extension FTOEP has a nominal first track outer magnetic field generating trace width dimension NFTOGTWD along the Y-axis direction. In accordance with the principles disclosed herein, each of the nominal first track field generation trace width dimensions NFTIGTWD and NFTOGTWD (which may be the same or different from each other) is at least the nominal first inner region width dimension YSEP1. It is 0.1 times. In some embodiments, the first track field generation trace width dimensions NFTIGTWD and NFTOGTWD are at least 0.15, at least 0.25, or at least 0.50 times the nominal first inner region width dimension YSEP1. May be advantageous.

  Each of the second track inner extension STIEP and the second track outer extension STOEP extends along the X-axis direction adjacent to the second inner region SINTA. The second track inner extension STIEP is positioned adjacent to the second track inner boundary STIB, and the second track outer extension STOEP is positioned adjacent to the second track outer boundary STEB. The second track inner extension STIEP has a nominal second track inner magnetic field generating trace width dimension NSTIGTWD along the Y-axis direction. The second track outer extension STOEP has a nominal second track outer field generating trace width dimension NSTOGTWD along the Y-axis direction. In accordance with the principles disclosed herein, each of the nominal second track field generation trace width dimensions NSTIGTWD and NSTOGTWD (which may be the same or different from each other) is at least the nominal second inner region width dimension YSEP2. It is 0.1 times. In some embodiments, the second track field generation trace width dimensions NSTIGTWD and NSTOGTWD are at least 0.15, at least 0.25, or at least 0.50 times the nominal second inner region width dimension YSEP2. May be advantageous. Other features and / or design relationships may also be made similar to the features and / or design relationships described with reference to FIG. 2, as appropriate.

  In various embodiments, in combination with the above features, at least a majority of the nominal sensing element width dimension NSEWD is included between the first track outer extension FTOEP and the second track outer extension STOEP. In some embodiments, most of the nominal sensing element width dimension NSEWD is included in the first inner area FINTA and the second inner area SINTA. In various embodiments, the magnetic field generating coil portion FGC and the sensing element SEN are isolated from one another. As shown in FIG. 7, the nominal sensing element width dimension NSEWD of the at least one sensing element SEN is greater than the total internal area width dimension OIAWD between the first track outer extension FTOEP and the second track outer extension STOEP. In addition, the inner edge IE of at least one of the first track outer extension FTOEP and the second track outer extension STOEP has an overlap dimension (eg, a first track overlap dimension FTOD and / or a second track overlap dimension STOD). Extends beyond the defined amount. In various embodiments, the field generating coil portion FGC is configured such that each nominal outer field generating trace width dimension (NFTOGTWD and NSTOGTWD) is greater than its associated overlap dimension. In various embodiments, all the extensions (FTIEP, FTOEP, STIEP and STOEP) are made in the first layer of the printed circuit board and the sensing element SEN is at least in the vicinity of the overlap dimension. It includes conductive loops created in one or more layers of the printed circuit board that include layers different from the layers.

  In the specific embodiment shown in FIG. 7, each of the first pattern track FPT and the second pattern track SPT has the same space along the X-axis direction in the first pattern track FPT and the second pattern track SPT. It may include the same type of signal modulation element SME arranged according to the target period or wavelength W. The signal modulation element SME in the second pattern track SPT is offset along the measurement axis direction (X-axis direction) by a nominal scale track offset STO of about W / 2 relative to the signal modulation element in the first pattern track ing. As indicated by the current flow arrow in FIG. 7, the magnetic field generating coil unit FGC generates the first track magnetic flux change having the first polarity in the first inner area FINTA, and the second inner In the region SINTA, a second track flux change having a second polarity opposite to the first polarity is generated. As mentioned above, the plurality of sensing elements SEN include a flux sensing loop (alternate sensing loop polarity along the X-axis direction) formed by the conductive traces created on the printed circuit board, At least a majority of each of the magnetic flux sensing loops extends along the Y-axis direction across the first inner area FINTA and the second inner area SINTA, and in each sensing element SEN, the first inner area FINTA and the second inner area. Provide the same detection loop polarity in the inner area SINTA. Since the polarity of the generated magnetic flux in the first inner area FINTA is opposite to the polarity of the generated magnetic flux in the second inner area SINTA, this is approximately W in the first pattern track FPT and the second pattern track SPT. Interacting with the signal modulation element SME with a scale track offset STO of / 2, an enhanced signal contribution is generated at each sensing element SEN.

  FIG. 8 is a plan view showing a fourth exemplary embodiment of the detection unit 867 and the compatible scale pattern 780 which can be used as the detection unit 167 and the scale pattern 180 in the electronic encoder shown in FIG. 1 and the like. is there. Scale pattern 780 shown in FIG. 8 may be similar or identical to scale pattern 780 shown in FIG. 7 and will not be described in detail below, except as it relates to its operation with detector 867. The detector 867 has features and components similar to the features and components of the detector 767 of FIG. 7, whose design and operation satisfy the same design principles as disclosed and claimed herein. As configured, it also provides similar advantages. Elements designated by reference numerals or labels in FIG. 8 that are the same as or identical to reference numerals or labels in FIG. 7 or other drawings in this specification (for example, suffixes with similar “XX” as in 8XX and 7XX) May be understood to designate similar elements and operate in the same manner unless indicated otherwise below. Accordingly, only important differences between the detection unit 867 and the detection unit 767 will be described in detail below.

  Similar to the detection unit 767, the detection unit 867 is configured for compatible operation with the scale pattern 780. The first track magnetic field generation coil unit FTFGCP surrounds the first inner area FINTA aligned with the first pattern track FPT, and along the X axis direction, the nominal first inner area length dimension FIALD, and the Y axis direction Along a nominal first inner region width dimension YSEP1 and responsive to the coil drive signal to generate a first flux change in the first inner region FINTA. Similarly, the second track magnetic field generation coil unit STFGCP surrounds the second inner area SINTA aligned with the second pattern track SPT, and has a nominal second inner area length dimension SIALD along the X-axis direction, A nominal second inner region width dimension YSEP2 is provided along the Y-axis direction, and a second magnetic flux change is generated in the second inner region SINTA in response to the coil drive signal.

  One important difference between the detection unit 867 and the detection unit 767 is that the magnetic field generating coil unit FGC has a first polarity in the first inner area FINTA, as indicated by the current flow arrow in FIG. And a second track flux change having a second polarity, which is the same as the first polarity, in the second inner area SINTA. In this regard, as described below, there is a second important difference in the plurality of sensing elements SEN (eg, SEN1, SEN14).

  Similar to the detection unit 767, in the detection unit 867, the plurality of detection elements SEN have a nominal detection element width dimension NSEWD along the Y-axis direction across the first inner area FINTA and the second inner area SINTA, The plurality of sensing elements SEN are configured to provide detector signals in response to local effects on the flux changes provided by the adjacent signal modulation elements SME of the scale pattern 780. The plurality of sensing elements SEN include magnetic flux sensing loops formed by conductive traces formed on the printed circuit board, at least a majority of each of the flux sensing loops forming a first inner region FINTA along the Y-axis direction. And the second inner area SINTA. However, in contrast to the sensing portion 767, each of the flux sensing loops shown in the sensing portion 867 provides opposite sensing loop polarities in the first inner region FINTA and the second inner region SINTA, Includes crossing or twisting of those conductive traces. In various embodiments, for at least a majority of the flux sensing loops, crossing or twisting of those conductive traces does not create unwanted signal disturbances, such that the first inner area FINTA and the second inner area SINTA And an “inactive” central region that includes a first track inner extension FTIEP and a second track inner extension STIEP therebetween.

  As shown in FIG. 8, the magnetic flux sensing loop of the sensing element SEN is also (generally, for example, illustrated by an exemplary sensing loop conductor diagram and the associated current flow arrows shown in the enlarged view at the bottom of FIG. The opposite detection loop polarity is configured to be alternated along the X-axis direction).

  According to the above description, since the polarity of the generated magnetic flux in the first inner area FINTA is the same as the polarity of the generated magnetic flux in the second inner area SINTA, this corresponds to the first pattern track FPT and the second pattern Interacting with the signal modulation element SME having a scale track offset STO of about W / 2 at track SPT, an enhanced signal contribution is generated at each of the "twisted" sensing elements SEN. A signal processor may be operatively connected to the detector to provide a coil drive signal, and from the illustrated sensing element SEN of the detector 867 (and according to known principles according to known methods) The relative position of the detector and the scale pattern is determined on the basis of the detection signal input from another sensing element SEN (not shown) provided to the phase position.

  As shown in FIG. 8, the magnetic field generating coil portion FGC and the sensing element SEN are advantageously configured in accordance with the principles already disclosed herein. The magnetic field generating coil portion FGC may include one or more of the illustrated feedthroughs to provide a shield configuration for one or more of the terminations EDP. Of course, the illustrated feedthroughs which may or may not be necessary in certain embodiments may be omitted. In accordance with the principles disclosed herein, each of the nominal first track field generation trace width dimensions NFTIGTWD and NFTOGTWD is at least 0.1 times the nominal first inner region width dimension YSEP1. In some embodiments, the first track field generation trace width dimensions NFTIGTWD and NFTOGTWD are at least 0.15, at least 0.25, or at least 0.50 times the nominal first inner region width dimension YSEP1. May be advantageous. According to the principles disclosed herein, each of the nominal second track field generation trace width dimensions NSTIGTWD and NSTOGTWD is at least 0.1 times the nominal second inner region width dimension YSEP2. In some embodiments, the second track field generation trace width dimensions NSTIGTWD and NSTOGTWD are at least 0.15, at least 0.25, or at least 0.50 times the nominal second inner region width dimension YSEP2. May be advantageous.

  Other features and / or design relationships used in detection unit 867 may also be made similar to compatible features and / or design relationships described with reference to detection unit 767, as appropriate. .

  Two-track scale patterns used in combination with magnetic field generation and sensing element polarities similar to those described above with reference to FIGS. 7 and 8 are detailed creation or layout considerations in the '958 patent. As disclosed without mentioning, it may help to reduce or eliminate certain signal offset components that may occur in single track scale pattern configurations. As already mentioned herein, conventional systems (e.g. the systems mentioned in the '958 patent) have relatively thin traces and / or relatively large internal areas (e.g. large internals) in the field generating coil section. The area FINTA and / or SINTA and / or the nominal coil area width dimension (first inner area width dimension YSEP1 and / or YSEP2) are used. In some prior systems, it was generally considered desirable that the sensing element of the sensing section be coupled with a relatively large area to receive flux changes within the field generating coil interior area. This is because it was considered to be advantageous with respect to current flow and signal strength. In contrast, according to the principles disclosed herein (e.g. for the overall detector Y-axis size restrictions imposed by a particular application, the inner area FINTA and / or SINTA and / or YSEP1 and / or YSEP2 At the expense of) a wider trace width is used, which results in a relatively small overall impedance to the field generating coil portion FGC, whereby a larger amount of current flows during a relatively short time (e.g. It is possible to generate a stronger signal) and also resonances can still be achieved for the desired length of time for the measurement. This is limited to relatively small first track pattern widths and second track pattern widths by practical considerations (eg, to stay in the same space as single track encoders used so far). This is particularly useful for the two track scale pattern that can be obtained. The two-track configuration, constructed in accordance with the principles disclosed herein, sometimes provides signal levels of equivalent prior art configurations that are more than 1.5 times greater when equivalent drive signals are input to the magnetic field generating coil portion. Furthermore, it has been found to achieve detection signal levels that are more than three times higher.

  While the preferred embodiments of the present disclosure have been illustrated and described, numerous variations in the arrangement and operation sequences of the illustrated and described features will be apparent to those skilled in the art based on the present disclosure. Various alternatives may be used to implement the principles disclosed herein.

  By way of example, the embodiments shown in FIGS. 2, 3, 7 and 8 and described with reference to FIGS. 2, 3, 7 and 8 have non-zero overlap dimensions OD, FTOD. , STOD, but this is not a requirement in all embodiments. As another example, the specific configuration of the sensing element SEN and the scale track offset STO shown in FIGS. 7 and 8 are merely illustrative and not limiting. Based on the above description and the disclosed principle, as can be understood by those skilled in the art, appropriate adaptation of the shape of the sensing element SEN to correspond to other scale track offsets STO corresponding to a specific scale track offset amount It may be used in combination with As another example, it should be appreciated that the signal modulation element SME may, in various embodiments, include loop elements or plate elements, or material property changes, and / or in various embodiments, the desired periodic signal. In order to generate a profile, it may have a dimension along the X-axis direction larger or smaller than W / 2 or W / 2. As another example, of course, the various features and principles disclosed herein may be applied to a rotary encoder, in which case the circular measurement axial direction and radial direction are mentioned in the above description The same applies to the X axis direction and the Y axis direction.

  The various embodiments and features described above may be combined to provide further embodiments. All U.S. patents and U.S. patent applications referenced herein are hereby incorporated by reference in their entirety. As appropriate, aspects of the embodiments may be modified to adopt the concepts of the various patents and applications to provide further embodiments.

These and other changes can be made to the embodiments in light of the above detailed description. In general, the terms used in the following claims should not be construed as limiting the claims to the specific embodiments disclosed in the specification and the claims, but rather on the equivalents of the claims. It should be construed to include all possible embodiments within the full scope.

Claims (20)

An electronic encoder that can be used to measure the relative position of two elements along a measurement axis direction that coincides with the X-axis direction,
A scale including a signal modulation scale pattern including a first pattern track and a second pattern track extending along the measurement axis direction and arranged parallel to each other, wherein each pattern track is the other pattern A track width dimension along a Y-axis direction perpendicular to the X-axis direction between the inner boundary of each pattern track closest to the track and the outer boundary of each pattern track farthest from the other pattern track Each scale comprises a signal modulation element arranged to provide spatially varying features that vary as a periodic function of position along the X-axis direction,
A detection unit mounted close to the pattern track and configured to move along the measurement axis direction with respect to the pattern track, the magnetic field generating coil unit fixed on a substrate; The detection unit including a plurality of detection elements arranged along an axial direction and fixed on the substrate;
A signal operatively connected to the detector to provide a coil drive signal and determining the relative position of the detector and the signal modulation scale pattern based on the detection signal input from the detector. A processing unit,
Including
The magnetic field generating coil unit
A first inner region aligned with the first pattern track is surrounded, and a nominal first inner region length dimension along the X axis direction and a nominal first inner region width dimension along the Y axis direction A first track magnetic field generating coil unit that generates a first magnetic flux change in the first inner region in response to the coil drive signal;
Surrounding a second inner region aligned with the second pattern track, the nominal second inner region length dimension along the X axis direction and the nominal second inner region width dimension along the Y axis direction A second track magnetic field generating coil unit which generates a second magnetic flux change in the second inner region in response to the coil drive signal;
Including
Each of the plurality of sensing elements has a nominal sensing element width dimension along the Y-axis direction across the first interior region and the second interior region, the plurality of sensing elements being the signal modulation scale Configured to provide a detection signal in response to local effects on the flux change provided by adjacent signal modulation elements of the pattern;
The magnetic field generating coil unit
An input unit including at least two connecting units for connecting the coil drive signal from the signal processing unit to the magnetic field generating coil unit;
Including stretchers and
The extension unit is
A first track inner extension and a first track outer extension that extend along the X axis direction adjacent to the first inner region;
A second track inner extension and a second track outer extension extending along the X-axis direction adjacent to the second inner region;
Including
The first track inner extension is positioned adjacent to the inner boundary of the first pattern track, and the first track outer extension is positioned adjacent to the outer boundary of the first pattern track, Each of the first track inner extension and the first track outer extension has a nominal first track magnetic field generating trace width dimension along the Y-axis direction,
The second track inner extension is positioned adjacent to the inner boundary of the second pattern track, and the second track outer extension is positioned adjacent to the outer boundary of the second pattern track, Each of the second track inner extension and the second track outer extension has a nominal second track magnetic field generation trace width dimension along the Y-axis direction,
At least half or more of the nominal sensing element width dimension is included between the first track outer extension and the second track outer extension;
In the magnetic field generating coil portion, each nominal second track magnetic field generation trace width dimension is such that each nominal first track magnetic field generation trace width dimension is at least 0.1 times the nominal first inner region width dimension, Electronic encoder, configured to be at least 0.1 times the nominal second inner region width dimension.   Each nominal first track field generation trace width dimension is at least 0.15 times the nominal first inner region width dimension, and each nominal second track field generation trace width dimension is the nominal second inner region width dimension The electronic encoder according to claim 1, which is at least 0.15 times.   Each nominal first track field generation trace width dimension is at least 0.25 times the nominal first inner region width dimension, and each nominal second track field generation trace width dimension is the nominal second inner region width dimension The electronic encoder according to claim 2, which is at least 0.25 times.   Each nominal first track field generation trace width dimension is at least 0.5 times the nominal first inner region width dimension, and each nominal second track field generation trace width dimension is the nominal second inner region width dimension The electronic encoder according to claim 2, which is at least 0.5 times.   Each nominal first track magnetic field generation trace width dimension and each nominal second track magnetic field generation trace width dimension is a skin depth of the extension at a nominal operating frequency defined corresponding to the detection signal generated in response to the magnetic flux change. The electronic encoder according to any one of claims 1 to 4, wherein the electronic encoder is at least 25 times as large. The magnetic field generating coil unit and the plurality of sensing elements are insulated from each other,
The nominal sensing element width dimension of the at least one sensing element is greater than the dimension spanning between the first track outer extension and the second track outer extension, the first track outer extension and the second Extends at least one inner edge of the track outer extension by an amount defined as an overlap dimension,
The electronic encoder according to any one of claims 1 to 5, wherein the magnetic field generating coil portion is configured such that each nominal magnetic field generating trace width dimension is larger than the overlap dimension.   The extension is made in a first layer of a printed circuit board, and the plurality of sensing elements comprise a layer different from the first layer, at least near the overlap dimension. The electronic encoder according to claim 6, comprising conductive loops made in one or more layers.   The electronic encoder according to any one of claims 1 to 7, wherein at least half or more of the nominal sensing element width dimension is included in the first inner region and the second inner region.   The electronic encoder according to any one of claims 1 to 5, wherein the substrate includes a printed circuit board, and at least the magnetic field generating coil unit includes a conductive trace formed on the printed circuit board.   The electronic encoder according to any one of claims 1 to 9, wherein an inner boundary of the first pattern track and an inner boundary of the second pattern track are positioned close to each other. The first pattern track and the second pattern track are the same in the first pattern track and the second pattern track, arranged according to the same spatial period or wavelength W along the X-axis direction The signal modulation elements of the second pattern track are of the type indicated by the nominal scale track offset of about W / 2 relative to the signal modulation elements in the first pattern track. Offset along the
The magnetic field generating coil unit generates a first track magnetic flux change having a first polarity in the first inner region, and a second of the second inner region opposite to the first polarity in the second inner region. Configured to generate a second track flux change having a polarity,
The plurality of sensing elements include flux sensing loops formed by conductive traces formed on a printed circuit board, at least half or more of each of the flux sensing loops being along the Y axis direction. The electronic encoder according to claim 1, wherein the same detection loop polarity is provided in the first inner region and the second inner region over the inner region and the second inner region. The first pattern track and the second pattern track are the same in the first pattern track and the second pattern track, arranged according to the same spatial period or wavelength W along the X-axis direction The signal modulation elements of the second pattern track are of the type indicated by the nominal scale track offset of about W / 2 relative to the signal modulation elements in the first pattern track. Offset along the
The magnetic field generating coil unit generates a first track magnetic flux change having a first polarity in the first inner region, and has a second polarity the same as the first polarity in the second inner region. Configured to generate a second track magnetic flux change,
The plurality of sensing elements include flux sensing loops formed by conductive traces formed on a printed circuit board, at least half or more of each of the flux sensing loops being along the Y axis direction. 2. The method of claim 1 including crossing or twisting of the conductive traces to provide opposing sense loop polarities in the first interior region and the second interior region across the interior region and the second interior region. Electronic encoder as described in.   For at least half or more of the flux sensing loop, the crossing or twisting of the conductive trace is the first track inner extension and the second track between the first inner region and the second inner region The electronic encoder according to claim 12, positioned in an area including an inner extension.   The electronic encoder according to any one of claims 1 to 13, wherein each of the first track magnetic field generating coil unit and the second track magnetic field generating coil unit includes a single turn surrounding each inner region. . The magnetic field generating coil unit extends substantially along the Y-axis direction, and faces the signal modulation scale pattern of the detection unit along a Z-axis direction which is perpendicular to the X-axis direction and the Y-axis direction. The at least one shielded end connected to the at least one extension nominally located at the z distance of the extension from the front surface,
The at least one shielded termination includes a shielded termination section that is nominally located at a z-distance of the shielded termination section from the front surface of the detector, wherein the z-distance of the shielded termination section is , Greater than the z-distance of the extension,
The detection unit further includes a conductive shield area that extends along the X-axis direction and the Y-axis direction and is nominally located at the z-distance of the shield area from the front surface, and the z-distance of the shield area is 15. A z-distance of the shielded termination section, wherein the shield area is disposed between at least a portion of the shielded termination section and the front surface of the sensing portion. The electronic encoder according to any one of the above.   The at least one shielded end portion may be a first track shield end portion connecting the first track inner extension and the first track outer extension, the second track inner extension and the second track. The electronic encoder according to claim 15, further comprising: a second track shield end connecting with the outer extension.   The extension is created in a first layer of a printed circuit board, the shielded termination section is created in a second layer of the printed circuit board, and the shield area is of the printed circuit board The electronic encoder according to claim 15 or 16, wherein the electronic encoder is made in a layer of the printed circuit board closer to the front surface than the second layer.   The electronic encoder according to claim 17, wherein the shield area is created in a layer of the printed circuit board disposed between the first layer and the second layer.   The electronic encoder according to claim 15, wherein the connection between the extension and the shielded end section includes a printed circuit board feedthrough extending along the Z-axis direction. The extension is created in a first layer of a printed circuit board, the shielded termination section is created in a second layer of the printed circuit board, and the shield area is the first layer. 20. The method according to claim 19, wherein the printed circuit board feedthrough is formed in a layer of the printed circuit board disposed between the first layer and the second layer, and the printed circuit board feedthrough penetrates an opening made in the shield area. Electronic encoder.

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