Capacitive grating displacement sensor

Abstract

This application provides a capacitive grating displacement sensor. A first grating includes multiple arrays of transmitting electrodes arranged in parallel and staggered configurations; each transmitting electrode array includes multiple transmitting electrodes periodically arranged along the staggered direction at a first pitch; the staggered spacing between any two transmitting electrode arrays is less than the first pitch; a second grating includes reflective electrodes arranged in a mesh pattern, the reflective electrodes spanning the multiple transmitting electrode arrays. By staggering the transmitting electrode arrays, the pitch, limited by process technology, is dispersed into staggered spacing between multiple transmitting electrode arrays, thereby overcoming the physical limitations of traditional pitch and enabling the capacitive grating displacement sensor to achieve higher precision displacement measurement under the same process conditions. The second grating employs a mesh reflective electrode structure, which reduces signal transmission resistance and enhances capacitive coupling.

Description

Technical Field

[0001] This application relates to the field of capacitive displacement measurement technology, and in particular to a capacitive grating displacement sensor. Background Technology

[0002] Capacitive grating sensors are widely used in various displacement measurement tools. However, due to limitations in manufacturing and assembly technologies, the space for reducing the grating pitch of capacitive grating sensors is very limited. This makes it difficult for phase-detection capacitive grating sensor displacement measurement systems to achieve higher resolution displacement measurement. Summary of the Invention

[0003] The main technical problem addressed by this application is to provide a capacitive grating displacement sensor, which solves the problem that existing phase-detection capacitive grating sensor displacement measurement systems cannot achieve higher resolution displacement measurement.

[0004] To address the aforementioned technical problems, the first technical solution provided in this application is: to provide a capacitive displacement sensor, comprising:

[0005] The first grid plate includes a plurality of emission electrode arrays arranged in parallel and staggered from each other; each emission electrode array includes a plurality of emission electrodes arranged periodically at a first pitch along the staggered direction; the staggered spacing between any two emission electrode arrays is less than the first pitch.

[0006] The second grid includes reflective electrodes arranged in a mesh pattern, the reflective electrodes spanning the plurality of emitting electrode arrays.

[0007] In some embodiments, the reflective electrode includes a plurality of first reflective electrode strips arranged periodically at a second pitch along the misalignment direction; the first reflective electrode strips extend along the arrangement direction, which is perpendicular to the misalignment direction; in the misalignment direction, the width of the emitting electrode is equal to the width of the first reflective electrode strips; and the second pitch is a non-zero integer multiple of the first pitch.

[0008] In some embodiments, the second pitch is greater than the first pitch.

[0009] In some embodiments, the phase of the excitation signal of each of the transmitting electrode arrays is uniformly distributed within a preset period.

[0010] In some embodiments, among the plurality of emitter electrode arrays, taking any one of the emitter electrode arrays as a reference, the offsets of each emitter electrode array relative to the reference form an arithmetic sequence, and the common difference of the arithmetic sequence is determined by the ratio of the first pitch to the total number of emitter electrode arrays.

[0011] In some embodiments, the reflective electrode further includes a plurality of second reflective electrode strips extending along the misalignment direction; each of the reflective electrode strips is connected to each of the first reflective electrode strips to form a mesh structure;

[0012] In the orthographic projection direction of the first grid plate, the projection of the second reflective electrode strip is misaligned with that of the emitting electrode array;

[0013] The first grid plate further includes at least one receiving electrode extending along the misalignment direction; in a direction perpendicular to the surface of the first grid plate, the reflecting electrode partially overlaps with the corresponding receiving electrode.

[0014] In some embodiments, there is one receiving electrode, which is disposed on one side of the plurality of transmitting electrode arrays along the arrangement direction, and the end of the reflecting electrode along the arrangement direction overlaps with the receiving electrode.

[0015] In some embodiments, there is one receiving electrode, which is located between any two adjacent transmitting electrode arrays, and the reflecting electrode spans the receiving electrode.

[0016] In some embodiments, there are two receiving electrodes, and the two receiving electrodes are disposed on opposite sides of the plurality of transmitting electrode arrays along the arrangement direction; the two ends of the reflecting electrode along the arrangement direction are respectively overlapped with the corresponding receiving electrodes.

[0017] In some embodiments, there are two receiving electrodes and two reflecting electrodes; the relative positions of the two transmitting electrodes are constant and their structures are identical; the two receiving electrodes each have an independent signal output path; and the transmitting electrodes and receiving electrodes are arranged in a one-to-one correspondence.

[0018] The end of the reflective electrode along the arrangement direction overlaps with the corresponding receiving electrode.

[0019] The beneficial effects of this application are as follows: Unlike existing technologies, this application provides a capacitive grating displacement sensor. The capacitive grating displacement sensor includes a first grating plate and a second grating plate. The first grating plate includes multiple arrays of transmitting electrodes arranged in parallel and staggered configurations; each transmitting electrode array includes multiple transmitting electrodes arranged periodically at a first pitch along the staggered direction; the staggered spacing between any two transmitting electrode arrays is less than the first pitch; the second grating plate includes reflective electrodes arranged in a mesh pattern, the reflective electrodes spanning the multiple transmitting electrode arrays. By staggering the transmitting electrode arrays, the pitch limited by the manufacturing process is dispersed into staggered spacings between multiple transmitting electrode arrays, thereby overcoming the physical limitations of traditional pitch and enabling the capacitive grating displacement sensor to achieve higher precision displacement measurement under the same manufacturing process conditions. The second grating plate adopts a mesh reflective electrode structure, which reduces signal transmission resistance and enhances capacitive coupling. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the first embodiment of the capacitive displacement sensor provided in this application.

[0022] Figure 2 for Figure 1 A schematic diagram showing the relative positions of the transmitting electrode, reflecting electrode, and receiving electrode in each transmitting electrode array;

[0023] Figure 3 This is an equivalent circuit diagram between the first gate plate and the second gate plate provided in the embodiments of this application;

[0024] Figure 4 yes Figure 1 A schematic diagram showing the coupling capacitance-displacement relationship between each emitting electrode array and the reflecting electrode.

[0025] Figure 5 This is a schematic diagram of the structure of the second embodiment of the capacitive grating displacement sensor provided in this application;

[0026] Figure 6 This is a schematic diagram of the third embodiment of the capacitive grating displacement sensor provided in this application.

[0027] Figure 7 This is a schematic diagram of the fourth embodiment of the capacitive grating displacement sensor provided in this application.

[0028] Figure 8 yes Figure 7 A schematic diagram showing the relative positions of the transmitting electrode, a reflecting electrode, and the receiving electrode in each transmitting electrode array;

[0029] Figure 9 This is a schematic diagram of the structure of an embodiment of the capacitive grating displacement sensor provided in this application;

[0030] Figure 10 This is a schematic diagram of the fifth embodiment of the capacitive grating displacement sensor provided in this application.

[0031] Figure 11 This is a schematic diagram of the fifth embodiment of the capacitive grating displacement sensor provided in this application.

[0032] Explanation of icon numbers:

[0033] 1. Capacitive grating displacement sensor; 100. First grating plate; 10. Transmitting electrode array; 101. Transmitting electrode group; 11. Transmitting electrode; 12. Receiving electrode; 13. Connecting bridge; 200. Second grating plate; 20. Reflecting electrode; 21. First reflective electrode strip; 22. Second reflective electrode strip; 300. Flexible circuit board; 400. Printed circuit board; L. First pitch; d. Second pitch; C1 / C2 / C3 / C4 / C0. Coupling capacitors. Detailed Implementation

[0034] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0035] In the following description, specific details such as particular system architectures, interfaces, and technologies are presented for illustrative purposes rather than for limiting purposes, in order to provide a thorough understanding of this application.

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] The terms "first," "second," and "third" in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indications also change accordingly. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0038] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0039] In existing technologies, capacitive grating sensors include a secondary grating and a primary grating that are parallel to each other but do not contact each other. The secondary grating has an emitter and a receiver, while the primary grating has a reflector and a shield. The relative displacement of the secondary and primary gratings changes the coupling capacitance between the emitter and reflector, resulting in a phase shift in the signals from the receiver and emitter. This phase-shifted electrical signal is then sent out through a data processing circuit, allowing the calculation of the relative displacement.

[0040] According to the measurement mechanism of active phase-detection capacitive grating technology, the phase difference obtained after phase detection is not linearly proportional to the displacement change of the capacitive grating sensor's gate, but rather has a deviation of about 0.1%. Therefore, a lower resolution is required to ensure a certain level of output accuracy. Furthermore, the frequency of the driving signal has a strong electrical correlation with the area of ​​the gate in the capacitive grating sensor. To meet the impedance matching requirements of the capacitive grating sensor and the chip, and to balance low power consumption and a certain resolution, the driving frequency of the capacitive grating sensor is typically set between 200Hz and 500Hz, while the operating frequency of the chip is set between 100kHz and 300kHz. This also results in a relatively low resolution for the measurement system. To improve the resolution, the grating pitch of the capacitive grating sensor needs to be reduced.

[0041] However, due to limitations in manufacturing and assembly technologies, the space for reducing the grating pitch of capacitive grating sensors is very limited, making it difficult for phase-detection capacitive grating sensor displacement measurement systems to achieve higher resolution displacement measurement.

[0042] Please see Figures 1 to 4 , Figure 1 This is a schematic diagram of the structure of the first embodiment of the capacitive displacement sensor provided in this application. Figure 2 for Figure 1 A schematic diagram showing the relative positions of the transmitting electrode, reflecting electrode, and receiving electrode in each transmitting electrode array. Figure 3 This is an equivalent circuit diagram between the first gate plate and the second gate plate provided in an embodiment of this application. Figure 4 yes Figure 1 A schematic diagram showing the coupling capacitance-displacement relationship between each emitting electrode array and the reflecting electrode.

[0043] To address the aforementioned technical problems, this application provides a capacitive grating displacement sensor 1, which includes a first grating plate 100 and a second grating plate 200. The first grating plate 100 includes a plurality of emitting electrode arrays 10 arranged in parallel and staggered relative to each other; each emitting electrode array 10 includes a plurality of emitting electrodes 11 periodically arranged along the staggered direction at a first pitch L; the staggered distance between any two emitting electrode arrays 10 is less than the first pitch L; the second grating plate 200 includes reflective electrodes 20 arranged in a mesh pattern, the reflective electrodes 20 spanning the plurality of emitting electrode arrays 10.

[0044] By staggering the arrangement of the emitting electrode array 10, the pitch limited by the manufacturing process is dispersed into staggered spacing between multiple emitting electrode arrays 10, thereby overcoming the physical limitations of traditional pitch and enabling the capacitive grating displacement sensor 1 to achieve higher precision displacement measurement under the same manufacturing process conditions. The second grating plate 200 adopts a mesh reflective electrode 20 structure, which reduces signal transmission resistance and enhances capacitive coupling effect.

[0045] The misalignment direction is the measurement direction.

[0046] During the measurement process, the first grid plate 100 and the second grid plate 200 have relative displacement along the measurement direction.

[0047] One of the first grid plate 100 and the second grid plate 200 is a fixed grid, and the other is a moving grid.

[0048] For example, the first grid plate 100 is a fixed grid, and the second grid plate 200 is a moving grid.

[0049] The first grid plate 100 and the second grid plate 200 are spaced apart in a direction perpendicular to the surface of the first grid plate 100.

[0050] Multiple emission electrode arrays 10 are arranged at intervals along an arrangement direction perpendicular to the misalignment direction.

[0051] Each of the emitting electrode arrays 10 is staggered with each other in pairs.

[0052] The misalignment direction includes unidirectional misalignment or bidirectional misalignment. A unidirectional misalignment direction is a vector direction extending along the misalignment direction, used to define the relative offset orientation between adjacent emitter electrode arrays 10.

[0053] The first pitch L is the center-to-center distance between two adjacent emitting electrodes 11 in the measurement direction. The first pitch L can also be called the grid pitch.

[0054] For example, in each emitter electrode array 10, the emitter electrodes 11 are of equal size and shape, and are equally spaced. In the emitter electrode array 10, the spacing between adjacent emitter electrodes 11 is equal to the width of the emitter electrode 11. That is, the first pitch L is twice the spacing between adjacent emitter electrodes 11.

[0055] In other embodiments, the spacing between adjacent emitter electrodes 11 in the emitter electrode array 10 may not be equal to the width of the emitter electrode 11.

[0056] The misalignment spacing between any two emitting electrode arrays 10 is less than the first pitch L, which facilitates the finer subdivision of physical measurement accuracy.

[0057] The transmitting electrode array 10 also includes a connecting bridge 13. The connecting bridge 13 is used to connect adjacent transmitting electrodes 11 so that each transmitting electrode 11 in the transmitting electrode array 10 is electrically connected to receive excitation signals.

[0058] The connecting bridge 13 and the emitting electrode 11 are located on different layers to avoid the connecting bridge 13 affecting the coupling effect between the emitting electrode 11 and the reflecting electrode 20.

[0059] The following description mainly uses a case where the number of emission electrode arrays 10 is 4. In other embodiments, the number of emission electrode arrays 10 may include, but is not limited to, 4.

[0060] In some embodiments, the reflective electrode 20 includes a plurality of first reflective electrode strips 21 arranged periodically along the misalignment direction at a second pitch d; the first reflective electrode strips 21 extend along the arrangement direction, which is perpendicular to the misalignment direction; in the misalignment direction, the width of the emitting electrode 11 is equal to the width of the first reflective electrode strips 21; the second pitch d is a non-zero integer multiple of the first pitch L.

[0061] By periodically arranging and oriented the reflective electrode strips, the capacitive coupling efficiency can be effectively improved, enabling a more precise correspondence between displacement changes and capacitance changes.

[0062] The equal width design of the first reflective electrode strip 21 and the emitting electrode 11 helps maintain the stability of capacitive coupling, while the multiple relationship between the second pitch d and the first pitch L enables periodic signal enhancement, providing a more reliable electrical basis for high-precision displacement detection. Simultaneously, the signal acquisition effect can be optimized by adjusting the pitch ratio between the emitting electrode 11 and the reflective electrode 20.

[0063] The mesh reflective electrode 20 can be made of metal mesh or woven conductive material, and its distribution density and shape can be adjusted according to the capacitive coupling requirements.

[0064] In some embodiments, the second pitch d is greater than the first pitch L.

[0065] For example, the second pitch d is twice the first pitch L.

[0066] The design that the second pitch d is greater than the first pitch L can reduce the difficulty of fabricating the mesh reflective electrode 20. For example, the mesh electrode may increase the difficulty of exposure.

[0067] The spacing between each emitting electrode array 10 along the arrangement direction is not limited here, and can be selected according to actual needs.

[0068] In some embodiments, the phase of the excitation signal of each emitter electrode array 10 is uniformly distributed within a preset period.

[0069] For example, a preset period is π.

[0070] The phase of the excitation signal of the transmitting electrode array 10 is uniformly distributed within a preset period, meaning that the phases of multiple excitation signals are distributed at equal intervals. For example, the phase difference of the excitation signals of the four transmitting electrode arrays 10 is π / 4. This distribution method, by uniformly dividing the phase difference into preset periods, makes the excitation signals of each transmitting electrode array 10 form equal angular intervals on the time axis.

[0071] In other embodiments, a preset period may be other values.

[0072] For example, multiple signal sources are used to generate sine waves or cosine waves with a fixed phase difference.

[0073] For example, the number of signal sources is the same as the number of transmitting electrode arrays 10.

[0074] In other embodiments, excitation signals with specific phase relationships can also be generated through digital signal processing.

[0075] like Figure 3 and Figure 4As shown, each transmitting electrode array 10 forms a coupling capacitor with the receiving electrode 12, denoted as C1, C2, C3, and C4 respectively. When the first grid plate 100 and the second grid plate 200 undergo relative displacement, the values ​​of each capacitor change accordingly (e.g., from C1=c, C2=c / 2, C3=0, C4=c / 2 when displacement is 0, to C1=c / 2, C2=c, C3=c / 2, C4=0 when displacement is L / 4). Simultaneously, the excitation signal of each transmitting electrode array 10 has a specific phase difference, causing the signal transmitted to the receiving electrode 12 through each coupling capacitor to have not only amplitude modulated by the capacitor value but also different phases. These four signals are vector-superimposed on the receiving electrode 12 through the receiving coupling capacitor C0, forming a composite signal whose amplitude and phase comprehensively reflect the relative displacement information, achieving accurate displacement detection.

[0076] When the displacement is a non-zero integer multiple of L, each coupling capacitor is the same as the coupling capacitor when the displacement is 0, thus forming a cycle. The cycle can be counted to determine the integer period of the displacement. Then, based on the coupling capacitor corresponding to each emitter electrode array 10 and by looking up the coupling capacitor-displacement pair table, the fine displacement value within the cycle can be obtained.

[0077] By uniformly distributing the phase of the excitation signal within the period, the capacitive grating displacement sensor 1 can achieve more uniform capacitive coupling characteristics during displacement changes, reducing errors caused by uneven phase distribution. This phase distribution method improves the stability of signal acquisition, enabling the phase detection circuit to more accurately capture phase difference changes, thereby improving the resolution and accuracy of displacement measurement. Simultaneously, the uniform phase distribution helps reduce mutual interference between multiple excitation signals, enhancing noise immunity and ultimately achieving more reliable displacement detection.

[0078] In some embodiments, among the plurality of emitter electrode arrays 10, with any one emitter electrode array 10 as a reference, the offsets of each emitter electrode array 10 relative to the reference form an arithmetic sequence, and the tolerance of the arithmetic sequence is determined by the ratio of the first pitch L to the total number of emitter electrode arrays 10.

[0079] The offset can be positive or negative.

[0080] The absolute value of the common difference of the arithmetic sequence is the ratio of the value of the first pitch L to the total number of the transmitting electrode array 10.

[0081] In some specific embodiments, such as Figure 1As shown, the misalignment distance between any two adjacent emitter electrode arrays 10 is equal. The misalignment direction is unidirectional. Specifically, the misalignment distance between two adjacent emitter electrodes 11 is L / 4. The four emitter electrode arrays 10 are sequentially offset at equal intervals along a single misalignment direction, forming a stepped arrangement. Taking the first emitter electrode array 10 as the reference, the arithmetic sequence includes L / 4, L / 2, and 3L / 4 in sequence.

[0082] In other specific embodiments, such as Figure 5 As shown, the misalignment direction is bidirectional. The misalignment direction includes opposite positive and negative offset directions. The four sequentially arranged emission electrode arrays 10 are defined as the first to the fourth emission electrode arrays 10. The second emission electrode array 10 is offset by L / 4 relative to the first emission electrode array 10 in the positive offset direction; the third emission electrode array 10 is offset by 3L / 4 relative to the second emission electrode array 10 in the negative offset direction; and the fourth emission electrode array 10 is offset by L / 4 relative to the third emission electrode array 10 in the positive offset direction. Based on the first emission electrode array 10, the arithmetic sequence includes -L / 2, -L / 4, 0, and L / 4.

[0083] In other embodiments, among the plurality of emitter electrode arrays 10, taking any one emitter electrode array 10 as a reference, the offsets of each emitter electrode array 10 relative to the reference form a non-arithmetic sequence. For example, the misalignment direction is unidirectional. The misalignment distance between the first emitter electrode array 10 and the second emitter electrode array 10 is L / 8, the misalignment distance between the second emitter electrode array 10 and the third emitter electrode array 10 is 3L / 8, and the misalignment distance between the third emitter electrode array 10 and the fourth emitter electrode array 10 is L / 4.

[0084] It should be understood that the staggered arrangement of each emitting electrode array 10 includes, but is not limited to, this.

[0085] In some embodiments, the reflective electrode 20 further includes a plurality of second reflective electrode strips 22 extending along the misalignment direction; each reflective electrode strip 20 is connected to each first reflective electrode strip 21 to form a mesh structure; in the orthogonal projection direction of the first grid plate 100, the projection of the second reflective electrode strip 22 is misaligned with the emitting electrode array 10; the first grid plate 100 further includes at least one receiving electrode 12 extending along the misalignment direction; in the direction perpendicular to the plate surface of the first grid plate, the reflective electrode 20 and the corresponding receiving electrode 12 are partially overlapped.

[0086] The first reflective electrode strip 21 and the second reflective electrode strip 22 are interwoven to form a mesh structure, which can reduce the signal transmission resistance and enhance the capacitive coupling effect.

[0087] The second reflective electrode strip 22 is misaligned with the emitting electrode array 10 in the orthogonal projection direction of the first grid plate 100. This misalignment design can optimize the electric field distribution and reduce signal interference.

[0088] An excitation signal is applied to the transmitting electrode 11. An electric field is generated around the transmitting electrode 11 and projected onto the reflecting electrode 20. The reflecting electrode 20 is suspended, meaning it is not energized. Although not energized, the reflecting electrode 20 is a conductor. According to electromagnetic principles, the electric field induces a charge on these suspended reflecting electrodes 20, generating an electric potential. The reflecting electrode 20, carrying the induced potential, also becomes a field source, emitting an electric field. At this time, the receiving electrode 12 induces a current / voltage signal within itself based on the electric field reflected from the reflecting electrode 20. The signal strength induced by the receiving electrode 12 depends on the overlap area between the transmitting electrode 11, the reflecting electrode 20, and the receiving electrode 12. A larger overlap area results in stronger electric field coupling and a stronger received signal.

[0089] The receiving electrode 12 and the reflecting electrode 20 are partially overlapped to enhance capacitive coupling.

[0090] For example, the overlapping area of ​​the reflective electrode 20 and the corresponding receiving electrode 12 is a block structure, which further enhances the capacitive coupling effect between the receiving electrode 12 and the reflective electrode 20 and the sensitivity to capacitance changes.

[0091] In the first specific embodiment, such as Figure 1 As shown, there is one receiving electrode 12, which is disposed on one side of the multiple transmitting electrode arrays 10 along the arrangement direction. The end of the reflecting electrode 20 along the arrangement direction overlaps with the receiving electrode 12.

[0092] For example, the receiving electrode 12 has a strip-shaped structure.

[0093] In other embodiments, the receiving electrode 12 may also be a mesh-like conductive layer. The shape of the receiving electrode 12 is not limited here and can be selected according to actual needs.

[0094] Please see Figure 1 , Figures 5 to 8 , Figure 5 This is a schematic diagram of the structure of the second embodiment of the capacitive displacement sensor provided in this application. Figure 6 This is a schematic diagram of the third embodiment of the capacitive displacement sensor provided in this application. Figure 7 This is a schematic diagram of the fourth embodiment of the capacitive displacement sensor provided in this application. Figure 8 yes Figure 7 A schematic diagram showing the relative positions of the transmitting electrode, a reflecting electrode, and the receiving electrode in each transmitting electrode array.

[0095] In the second specific embodiment, such as Figure 5 As shown, there is one receiving electrode 12, which is located between any two adjacent transmitting electrode arrays 10, and the reflecting electrode 20 spans the receiving electrode 12.

[0096] For example, the receiving electrode 12 is located between the second and third transmitting electrode arrays 10.

[0097] The receiving electrode 12 is located between any two adjacent transmitting electrode arrays 10, such that the reflecting electrode 20 is partially disposed on opposite sides of the receiving electrode 12, which can reduce the load on the reflecting electrode 20.

[0098] In the third specific embodiment, such as Figure 6 As shown, there are two receiving electrodes 12, and the two receiving electrodes 12 are disposed on opposite sides of the multiple transmitting electrode arrays 10 along the arrangement direction; the two ends of the reflecting electrode 20 along the arrangement direction are respectively overlapped with the corresponding receiving electrode 12.

[0099] The receiving electrodes 12 are arranged in two, respectively on both sides of the transmitting electrode array 10, and the reflecting electrodes 20 overlap with the corresponding receiving electrodes 12 at both ends of the arrangement direction. This structure can enhance the capacitive coupling efficiency by synchronously acquiring signals through the receiving electrodes 12 on both sides, while the overlapping design of the reflecting electrodes 20 and the receiving electrodes 12 can optimize the electric field distribution.

[0100] The receiving electrode 12 is arranged in two positions, located on both sides of the transmitting electrode array 10. This effectively improves the sensitivity of the capacitance signal acquisition, making the capacitance change corresponding to a small displacement more significant, thereby improving the measurement resolution. The overlapping design of the two ends of the reflecting electrode 20 with the corresponding receiving electrode 12 enhances the electric field concentration effect and reduces signal attenuation.

[0101] In the fourth specific embodiment, such as Figure 7 As shown, there are two receiving electrodes 12 and two reflecting electrodes 20; the relative positions of the two transmitting electrodes 11 are constant and their structures are the same; the two receiving electrodes each have an independent signal output path; the transmitting electrodes 11 and the receiving electrodes 12 are arranged in a one-to-one correspondence; the end of the reflecting electrode 20 along the arrangement direction overlaps with the corresponding receiving electrode 12.

[0102] The two reflective electrodes 20 maintain a preset distance to reduce signal interference.

[0103] During the measurement process, the reflective electrode 20 is offset from another receiving electrode 12 (i.e., non-corresponding receiving electrode 12) to maintain a certain distance, so as to avoid the electric field emitted by the reflective electrode 20 from affecting the sensing signal of the other receiving electrode 12.

[0104] The transmitting electrode 11 and the receiving electrode 12 form a corresponding pairing relationship, which can form two sets of measurement structures. By measuring simultaneously through the two sets of measurement structures, the accuracy of the measurement can be identified. When the difference between the two sets of measurement values ​​is too large, the measurement equipment can be promptly alerted to abnormality.

[0105] For example, the two receiving electrodes 12 are located on opposite sides of the plurality of transmitting electrode arrays 10 and are arranged diagonally.

[0106] In some embodiments, the extension length of the receiving electrode 12 along the misalignment direction is less than the extension length of the transmitting electrode array 10 along the misalignment direction, so as to reduce signal interference between the two sets of measurement structures during the measurement process.

[0107] Furthermore, in some specific embodiments, the extension length of the receiving electrode 12 along the misalignment direction is less than or equal to half the extension length of the transmitting electrode array 10 along the misalignment direction, which reduces signal interference while maximizing the measurement range.

[0108] Each reflective electrode 20 has the same overlapping area with its corresponding receiving electrode 12 to reduce error interference caused by different overlapping areas.

[0109] The overlap area between the two reflective electrodes 20 and the corresponding emitter electrodes 11 in the same emitter electrode array 10 can be the same or different.

[0110] For example, each reflective electrode 20 has the same shape and size, and the overlap area between the reflective electrode 20 and the corresponding emitting electrode 11 in the emitting electrode array 10 is determined by their overlap width. For example, if the overlap width is the same, then the overlap area is the same.

[0111] For example, the overlap widths of a reflective electrode 20 and the corresponding emitter electrodes 11 in the four emitter electrode arrays 10 are L / 4, 0, L / 4, and L / 2, respectively (see...). Figure 2 and Figure 7 The overlap widths of the other reflective electrode 20 with the corresponding emitter electrodes 11 in the four emitter electrode arrays 10 are 0, L / 4, L / 2, and L / 4 respectively (see...). Figure 7 and Figure 8 ).

[0112] By setting two independent receiving electrodes 12 and corresponding reflecting electrodes 20, the stability of capacitive coupling and the reliability of signal acquisition can be enhanced. The overlapping design of the end of the reflecting electrode 20 with the receiving electrode 12 can effectively improve the electric field coupling efficiency, thereby enhancing the signal strength acquired by the receiving electrode 12. The two transmitting electrodes 11 maintain a fixed position and identical structure, reducing measurement errors caused by structural deviations.

[0113] In some embodiments, the capacitive grating displacement sensor 1 further includes a phase identification circuit (not shown) and a counting circuit (not shown).

[0114] The phase direction detection circuit is configured to receive the induced signal output by the receiving electrode 12 when the first gate plate 100 and the second gate plate 200 are relatively displaced, and output a direction signal representing the logic level of the displacement direction by identifying whether the phase leads or lags.

[0115] The counting circuit is connected to the output of the phase direction detection circuit. It is configured as a reversible counter, using the direction signal as the control input for the addition and subtraction counting mode, to count the subdivided displacement pulses. In this way, the phase direction detection circuit and the counting circuit work together to convert the vector information of the relative displacement into a precise digital output, thereby realizing displacement direction discrimination and displacement accumulation.

[0116] The induced signal output by the receiving electrode 12 is periodic. The relative displacement between the first grid plate 100 and the second grid plate 200 is one first pitch L, and the induced signal completes one cycle. The cycles (or pulses) of the induced signal are continuously counted to accumulate the total relative displacement.

[0117] The counting circuit counts the periods of the sensed signal to determine the integer periodic portion of the displacement. Then, by detecting the phase difference of the signal and consulting a pre-stored phase-displacement correspondence table or other methods, it obtains the fine displacement value within the period. Finally, it fuses the two values ​​to output a precise and unique position value. Thus, by using the number of cycle cycles and the phase difference, the precise value of the relative displacement between the first grid plate 100 and the second grid plate 200 can be obtained.

[0118] Please see Figure 9 , Figure 9 This is a schematic diagram of the structure of an embodiment of the capacitive displacement sensor provided in this application.

[0119] In some embodiments, the capacitive grid displacement sensor 1 further includes a flexible circuit board 300 and a printed circuit board 400. The printed circuit board 400 is connected to the first grid plate 100 via the flexible circuit board 300.

[0120] For example, the phase identification circuit and the counting circuit can be integrated into the printed circuit board 400.

[0121] Please see Figure 10 and Figure 11 , Figure 10 This is a schematic diagram of the fifth embodiment of the capacitive displacement sensor provided in this application. Figure 11 This is a schematic diagram of the fifth embodiment of the capacitive grating displacement sensor provided in this application.

[0122] This application also provides a capacitive grating displacement sensor 1, which includes a first grating plate 100 and a second grating plate 200. The first grating plate 100 includes a transmitting electrode group 101, which includes a plurality of transmitting electrode arrays 10 arranged periodically at a first pitch L along a preset direction and spaced apart; each transmitting electrode array 10 includes a plurality of transmitting electrodes 11 arranged periodically along the preset direction; the second grating plate 200 includes a reflecting electrode 20; the reflecting electrode 20 includes a plurality of first reflecting electrode strips 21; wherein, a transmitting electrode group 101 and a reflecting electrode 20 constitute a measurement group; in the measurement group, in the preset direction, with the transmitting electrode 11 at the same position in each transmitting electrode array 10 as a reference, the offset of each first reflecting electrode strip 21 relative to the corresponding reference is not equal.

[0123] By making the offset of each first reflective electrode strip 21 in the measurement group unequal relative to the corresponding reference, the pitch limited by the process is dispersed into multiple offsets in the measurement group, thereby breaking through the physical limitations of the traditional pitch and enabling the capacitive grating displacement sensor 1 to achieve higher precision displacement measurement under the same process conditions.

[0124] In some embodiments, there are multiple emitting electrode groups 101 and / or multiple reflecting electrodes 20, such that all emitting electrode groups and all reflecting electrodes 20 constitute multiple measurement groups with different measurement accuracies.

[0125] The design of multiple measurement groups with different measurement accuracies allows the capacitive displacement sensor 1 to be selected in terms of measurement accuracy, thereby enabling flexible selection of measurement accuracy and range according to application requirements and achieving synergistic optimization of performance and efficiency.

[0126] In other embodiments, the capacitive grating displacement sensor 1 includes a first grating plate 100 and a second grating plate 200. The first grating plate 100 includes a first stage (not shown) and a plurality of emitting electrode arrays 10, each emitting electrode array 10 including a plurality of emitting electrodes 11 arranged periodically at a first pitch L along a preset direction; the second grating plate 200 includes a second stage (not shown) and a reflective electrode 20; the reflective electrode 20 includes a first reflective electrode strip 21; wherein the emitting electrode arrays 10 are adjustablely disposed on the first stage, and / or the first reflective electrode strips are adjustablely disposed on the second stage; in the preset direction, with the emitting electrode 11 at the same position in each emitting electrode array 10 as a reference, the offset of each first reflective electrode strip 21 relative to the corresponding reference is not equal, and the offset is adjustable.

[0127] By making the offsets of each first reflective electrode strip 21 relative to its corresponding reference unequal, the pitch, limited by the manufacturing process, is dispersed into multiple offsets, thereby overcoming the physical limitations of traditional pitch and enabling the capacitive grating displacement sensor 1 to achieve higher precision displacement measurement under the same manufacturing process conditions. Simultaneously, the adjustable design of the emitting electrode array 10 and / or the first reflective electrode strips 21 allows for adjustment of the offset between the emitting electrode array 10 and the first reflective electrode strips 21 according to the required measurement accuracy, making the measurement accuracy of the capacitive grating displacement sensor 1 adjustable and achieving synergistic optimization of performance and efficiency.

[0128] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0129] The above are merely embodiments of this application and do not limit the scope of patent protection of this application. Any equivalent structural or procedural changes made using the content of this application’s specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A capacitive displacement sensor, characterized in that, include: The first grid plate includes a plurality of emission electrode arrays arranged in parallel and staggered from each other; each emission electrode array includes a plurality of emission electrodes arranged periodically at a first pitch along the staggered direction; the staggered spacing between any two emission electrode arrays is less than the first pitch; The second grid includes reflective electrodes arranged in a mesh pattern, the reflective electrodes spanning the plurality of emitting electrode arrays; The reflective electrode includes a plurality of first reflective electrode strips arranged periodically at a second pitch along the misalignment direction; the first reflective electrode strips extend along the arrangement direction, which is perpendicular to the misalignment direction; the second pitch is a non-zero integer multiple of the first pitch. The reflective electrode further includes a plurality of second reflective electrode strips extending along the misalignment direction; each second reflective electrode strip is connected to each of the first reflective electrode strips to form a mesh structure; In the orthogonal projection direction of the first grid plate, the projection of the second reflective electrode strip is misaligned with that of the emitting electrode array.

2. The capacitive displacement sensor according to claim 1, characterized in that, In the misalignment direction, the width of the emitting electrode is equal to the width of the first reflective electrode strip.

3. The capacitive displacement sensor according to claim 2, characterized in that, The second pitch is greater than the first pitch.

4. The capacitive displacement sensor according to claim 1, characterized in that, The phase of the excitation signal of each of the transmitting electrode arrays is uniformly distributed within a preset period.

5. The capacitive displacement sensor according to claim 4, characterized in that, In the plurality of emission electrode arrays, taking any one of the emission electrode arrays as a reference, the offsets of each emission electrode array relative to the reference form an arithmetic sequence, and the common difference of the arithmetic sequence is determined by the ratio of the first pitch to the total number of emission electrode arrays.

6. The capacitive displacement sensor according to claim 2, characterized in that, The first grid plate further includes at least one receiving electrode extending along the misalignment direction; in a direction perpendicular to the surface of the first grid plate, the reflecting electrode partially overlaps with the corresponding receiving electrode.

7. The capacitive displacement sensor according to claim 6, characterized in that, The receiving electrode is a single electrode, which is disposed on one side of the plurality of transmitting electrode arrays along the arrangement direction, and the end of the reflecting electrode along the arrangement direction overlaps with the receiving electrode.

8. The capacitive displacement sensor according to claim 6, characterized in that, There is one receiving electrode, which is located between any two adjacent transmitting electrode arrays, and the reflecting electrode spans across the receiving electrode.

9. The capacitive displacement sensor according to claim 6, characterized in that, There are two receiving electrodes, and the two receiving electrodes are disposed on opposite sides of the plurality of transmitting electrode arrays along the arrangement direction; the two ends of the reflecting electrode along the arrangement direction are respectively overlapped with the corresponding receiving electrodes.

10. The capacitive displacement sensor according to claim 6, characterized in that, There are two receiving electrodes and two reflecting electrodes; the relative positions of the two transmitting electrodes are constant and their structures are identical; each of the two receiving electrodes has an independent signal output path; the transmitting electrode and the receiving electrode are arranged in a one-to-one correspondence. The end of the reflective electrode along the arrangement direction overlaps with the corresponding receiving electrode.

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