Capacitive displacement sensor

Abstract

The invention provides a capacitive displacement sensor. The offset of each reflecting electrode strip relative to the corresponding first reference is unequal, and the pitch limited by the manufacturing process is dispersed into a plurality of offsets, so that the physical limitation of the traditional pitch is broken through, and the displacement measurement with higher precision can be realized by the capacitive grating displacement sensor under the same manufacturing process condition. Meanwhile, due to the adjustable design of the emission electrode array and / or the reflection electrode strip, the offset of the emission electrode array and the reflection electrode strip can be adjusted according to the required measurement precision, so that the measurement precision of the capacitive grating displacement sensor is adjustable, and collaborative optimization of performance and efficiency is realized.

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: The first grid plate includes a first stage and a plurality of emission electrode arrays, each of the emission electrode arrays including a plurality of emission electrodes arranged in a predetermined direction at a first pitch period. The second grid plate includes a second stage and a reflective electrode; the reflective electrode includes a reflective electrode strip. The emitting electrode array is adjustablely disposed on the first stage, and / or the reflecting electrode strip is adjustablely disposed on the second stage; In the preset direction, taking the emitting electrodes at the same position in each of the emitting electrode arrays as a first reference, the offsets of each of the reflective electrode strips relative to the corresponding first reference are not equal, and the offsets are adjustable.

[0005] In some embodiments, the first grid plate further includes a plurality of first substrates, each of which is equipped with an emission electrode array, and the offset is adjusted by adjusting the relative displacement between the first substrate and the first stage along the preset direction; In the preset direction, the width of the emitting electrode is equal to the width of the corresponding reflective electrode strip.

[0006] In some embodiments, the first substrate is slidably connected to the first stage; or, the first substrate is detachably disposed on the first stage to enable replacement of the first substrate.

[0007] In some embodiments, the first stage has a first assembly scale extending along the preset direction, and the mounting position of the first substrate is determined based on the first assembly scale; the line width and line spacing of the first assembly scale are both equal to the width of the emitting electrode.

[0008] In some embodiments, each of the emitting electrode arrays corresponds to at least one of the reflective electrode strips; the reflective electrode strips corresponding to each emitting electrode array constitute a reflective electrode group; The second grid plate also includes a second substrate, and each second substrate is equipped with a set of the reflective electrodes. The offset is adjusted by adjusting the relative displacement between the second substrate and the second stage along the preset direction. When there are multiple reflective electrode strips in the reflective electrode group, the reflective electrode strips are arranged in a second pitch period, and the second pitch is an integer multiple of the first pitch.

[0009] In some embodiments, the second stage has a second assembly scale extending along the preset direction, and the mounting position of the second substrate is determined based on the second assembly scale; the line width and line spacing of the second assembly scale are both equal to the width of the reflective electrode strip.

[0010] In some embodiments, the reflective electrode strips corresponding to each of the emitting electrode arrays constitute a reflective electrode group; the emitting electrode arrays are arranged in a third pitch period; the third pitch is n times the first pitch, where n is an integer; in the preset direction, the center distance between any adjacent reflective electrode groups is greater than n times the first pitch and less than n+1 times the first pitch.

[0011] In some embodiments, the reflective electrode strips corresponding to each of the emitting electrode arrays constitute a reflective electrode group; the reflective electrode group is arranged periodically along the preset direction with a fourth pitch; the fourth pitch is m times the first pitch, where m is an integer; in the preset direction, the center-to-center distance between any adjacent emitting electrode arrays is greater than m-1 times the first pitch and less than m times the first pitch.

[0012] In some embodiments, the reflective electrode strips corresponding to each of the emitting electrode arrays constitute a reflective electrode group; the reflective electrode strips at the same position in each of the reflective electrode groups are defined as a second reference; In the preset direction, the offsets of each second reference relative to the corresponding first reference form an arithmetic sequence, and the tolerance of the arithmetic sequence is determined by the ratio of the first pitch to the total number of the transmitting electrode array.

[0013] In some embodiments, the phase of the excitation signal of each of the transmitting electrode arrays is uniformly distributed within a preset period.

[0014] The beneficial effects of this application are as follows: Unlike existing technologies, this application provides a capacitive grating displacement sensor, comprising a first grating plate and a second grating plate. The first grating plate includes a first stage and multiple transmitting electrode arrays, each transmitting electrode array including multiple transmitting electrodes arranged periodically at a first pitch along a preset direction. The second grating plate includes a second stage and a reflecting electrode; the reflecting electrode includes a reflecting electrode strip. The transmitting electrode arrays are adjustablely disposed on the first stage, and / or the reflecting electrode strips are adjustablely disposed on the second stage. In the preset direction, using the transmitting electrodes at the same position in each transmitting electrode array as a first reference, the offsets of each reflecting electrode strip relative to the corresponding first reference are unequal, and the offsets are adjustable. By making the offsets of each reflecting electrode strip relative to the corresponding first 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 to achieve higher precision displacement measurement under the same manufacturing process conditions. Meanwhile, the adjustable design of the emitting electrode array and / or reflective electrode strip allows for adjustment of the offset between the emitting electrode array and the reflective electrode strip according to the required measurement accuracy, making the measurement accuracy of the capacitive displacement sensor adjustable and achieving synergistic optimization of performance and efficiency. Attached Figure Description

[0015] 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.

[0016] 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 emitting electrode array and the reflecting electrode strips; Figure 3 This is a schematic diagram of the structure of a second embodiment of the capacitive displacement sensor provided in this application. Figure 4 This is a schematic diagram of the third embodiment of the capacitive displacement sensor provided in this application. Figure 5 This is a schematic diagram of the structure of the fourth embodiment of the capacitive grating displacement sensor provided in this application. Figure 6 This is a schematic diagram of the structure of the fifth embodiment of the capacitive displacement sensor provided in this application. Figure 7 A schematic diagram of the structure of a first embodiment of a measurement group provided in this application; Figure 8A schematic diagram of the structure of a second embodiment of a measurement group provided in this application; Figure 9 A schematic diagram of the structure of a third embodiment of a measurement group provided in this application; Figure 10 This is a schematic diagram of the equivalent circuit between the first gate plate and the second gate plate provided in an embodiment of this application; Figure 11 for Figure 10 A schematic diagram showing the coupling capacitance-displacement relationship between each emitting electrode array and the reflecting electrode. Figure 12 This is a schematic diagram of the sixth embodiment of the capacitive displacement sensor provided in this application. Figure 13 This is a schematic diagram of the structure of an embodiment of the second grid plate provided in this application. Figure 14 This is a schematic diagram of the structure of the seventh embodiment of the capacitive displacement sensor provided in this application. Figure 15 A schematic diagram of the structure of the emitting electrode array, the reflecting electrode strip, and the first assembly scale provided in the embodiments of this application; Figure 16 A schematic diagram of the structure of the transmitting electrode array, the reflecting electrode strip, and the first assembly scale provided in the second embodiment of this application; Figure 17 A schematic diagram of the structure of the emitting electrode array, the reflecting electrode strip, and the first assembly scale provided in the third embodiment of this application; Figure 18 A schematic diagram of the structure of the emitting electrode array, the reflecting electrode strip, and the first assembly scale provided in the fourth embodiment of this application; Figure 19 This is a schematic diagram of an embodiment of the capacitive displacement sensor provided in this application.

[0017] Explanation of icon numbers: 1. Capacitive grating displacement sensor; 100. First grating plate; 110. First stage; 10. Transmitting electrode array; 101. Transmitting electrode group; 11. Transmitting electrode; 12. Receiving electrode; 13. Connecting bridge; 14. First substrate; 15. First assembly scale; 200. Second grating plate; 210. Second stage; 20. Reflecting electrode; 201. Second substrate; 21. Reflecting electrode strip; 22. Reflecting electrode group; 23. Reflecting electrode block; 24. Second assembly scale; 300. Flexible circuit board; 400. Printed circuit board; L1. First pitch; L2. Second pitch; L3. Third pitch; L4. Fourth pitch; C1 / C2 / C3 / C4 / C0. Coupling capacitors. Detailed Implementation

[0018] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] Please see Figure 1 and Figure 2 , 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 emitting electrode array and the reflecting electrode strip.

[0027] To address the aforementioned technical problems, this application provides a capacitive grating displacement sensor 1, comprising a first grating plate 100 and a second grating plate 200. The first grating plate 100 includes an emitting electrode group 101, which includes a plurality of emitting electrode arrays 10 arranged along a first direction; each emitting electrode array 10 includes a plurality of emitting electrodes 11 periodically arranged along the first direction. The second grating plate 200 includes a reflective electrode 20; the reflective electrode 20 includes a plurality of reflective electrode strips 21. A emitting electrode group 101 and a reflective electrode 20 constitute a measurement group. In the measurement group, in the first direction, the emitting electrodes 11 at the same position in each emitting electrode array 10 are used as a first reference, and the offsets of each reflective electrode strip 21 relative to the corresponding first reference are not equal.

[0028] By making the offset of each reflective electrode strip 21 in the measurement group unequal relative to the corresponding first 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.

[0029] The first direction is the direction of the linear vector. The first direction is parallel to the measurement direction.

[0030] During the measurement process, the first grid plate 100 and the second grid plate 200 have relative displacement along the measurement direction.

[0031] One of the first grid plate 100 and the second grid plate 200 is a fixed grid, and the other is a moving grid.

[0032] For example, the first grid plate 100 is a fixed grid, and the second grid plate 200 is a moving grid.

[0033] 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.

[0034] The number of emitting electrode arrays 10 in each reflective electrode group 22 can be equal or unequal, depending on the actual needs.

[0035] For example, all the emitter electrode arrays 10 in the emitter electrode group 101 are arranged along a first direction and aligned at both ends perpendicular to the first direction.

[0036] In other embodiments, the emission electrode arrays 10 in the emission electrode group 101 are arranged sequentially at intervals along a first direction, and at least some adjacent emission electrode arrays 10 are staggered along a direction perpendicular to the first direction.

[0037] In the measurement group, each reflective electrode strip 21 spans the corresponding emitting electrode array 10.

[0038] 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.

[0039] 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 corresponding reflective electrode 20.

[0040] There is at least one emitting electrode assembly 101.

[0041] For example, such as Figure 1 As shown, there is one emitting electrode group 101.

[0042] In some embodiments, there are multiple emitting electrode groups 101 and / or multiple reflecting electrodes 20, such that all emitting electrode groups 101 and all reflecting electrodes 20 constitute multiple measurement groups with different measurement accuracies; the first grid plate 100 also includes at least one receiving electrode 12 extending along a first direction; in a direction perpendicular to the plate surface of the first grid plate 100, the reflecting electrode 20 and the corresponding receiving electrode 12 are partially overlapped; the emitting electrode group 101 is located on the side of the receiving electrode 12 along a second direction, and the first direction is perpendicular to the second direction.

[0043] The design of multiple measurement groups with different measurement accuracies allows the measurement accuracy of the capacitive displacement sensor 1 to be selected, thus enabling flexible selection of measurement accuracy according to application requirements and achieving synergistic optimization of performance and efficiency.

[0044] An excitation signal is applied to the transmitting electrode 11. An electric field is generated around the transmitting electrode 11 and projected onto the corresponding 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.

[0045] The receiving electrode 12 and the reflecting electrode 20 are partially overlapped to enhance capacitive coupling.

[0046] 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.

[0047] In the measurement group, the reflective electrode strips 21 extend along the second direction and are arranged at intervals along the first direction.

[0048] One measurement group corresponds to one receiving electrode 12. Measurement groups can share the same receiving electrode 12 or correspond to different receiving electrodes 12.

[0049] When there are multiple transmitting electrode groups 101, the multiple transmitting electrode groups 101 operate in a time-sharing manner to reduce signal interference.

[0050] Please participate Figures 3 to 6 , Figure 3 This is a schematic diagram of the structure of the second embodiment of the capacitive displacement sensor provided in this application. Figure 4 This is a schematic diagram of the third embodiment of the capacitive displacement sensor provided in this application. Figure 5 This is a schematic diagram of the fourth embodiment of the capacitive displacement sensor provided in this application. Figure 6 This is a schematic diagram of the fifth embodiment of the capacitive displacement sensor provided in this application.

[0051] like Figure 3As shown, in the first specific embodiment, there are two transmitting electrode groups 101, which are located on the same side of the receiving electrode 12; and one reflecting electrode 20.

[0052] Two emitting electrode groups 101 and one reflecting electrode 20 can each form two measurement groups.

[0053] The two measurement groups share the same receiving electrode 12 and the same reflecting electrode 20 to reduce the number of receiving electrodes 12 and reflecting electrodes 20, thereby saving costs.

[0054] For example, in the first measurement group, each emitting electrode array 10 corresponds to two reflective electrode strips 21, and the two corresponding reflective electrode strips 21 have the same overlap area with their respective emitting electrodes 11, so as to increase the coupling effect between the emitting electrode 11 and the reflective electrode 20. In the second measurement group, each emitting electrode array 10 corresponds to one reflective electrode strip 21, and the offset of each reflective electrode strip 21 relative to the corresponding first reference is not equal.

[0055] The two measurement groups have different measurement accuracies for users to choose from.

[0056] like Figure 4 and Figure 5 As shown, in the second specific embodiment, there are two transmitting electrode groups 101, which are located on opposite sides of the receiving electrode 12 respectively; there are two reflecting electrodes 20, which are spaced apart and correspond to the same receiving electrode 12; or, there is one reflecting electrode 20, which spans one transmitting electrode group 101, the receiving electrode 12 and another transmitting electrode group 101 in sequence.

[0057] There are two emission electrode groups 101, which can form two measurement groups.

[0058] Two transmitting electrode groups 101 are located on opposite sides of the receiving electrode 12 along the second direction, so as to reduce the distance between each transmitting electrode group 101 and the receiving electrode 12, thereby reducing the extension length of the reflecting electrode strip 21 along the second direction, thereby reducing the impedance and enhancing the coupling effect.

[0059] like Figure 4 As shown, in some embodiments, there are two reflective electrodes 20, which are spaced apart and correspond to the same receiving electrode 12, in order to reduce the number of receiving electrodes 12 and save costs; and each transmitting electrode group 101 corresponds to a different reflective electrode 20 to reduce interference.

[0060] like Figure 5As shown, in some other embodiments, there is one reflective electrode 20, which spans one emitter electrode group 101, the receiver electrode 12 and another emitter electrode group 101 in sequence, so that the two measurement groups share the same receiver electrode 12, which facilitates the preparation of the receiver electrode 12.

[0061] like Figure 6 As shown, in the third specific embodiment, there is one transmitting electrode group 101; there are two receiving electrodes 12, which are located on opposite sides of the transmitting electrode group 101; there are two reflecting electrodes 20, which are arranged opposite to each other along the first direction and are arranged in a one-to-one correspondence with the receiving electrodes 12.

[0062] A transmitting electrode group 101 and two receiving electrodes 12 can respectively form two measurement groups.

[0063] In the first direction, there is an overlapping area between the two reflective electrodes 20.

[0064] For example, in each measurement group, each emitting electrode array 10 corresponds to one reflective electrode strip 21. Each emitting electrode array 10 corresponds to two reflective electrode strips 21 located in different measurement groups, so that the reflective electrode strips 21 in the two reflective electrodes 20 are alternately arranged in the first direction. This design can not only reduce the number of emitting electrode arrays 10, but also reduce the extension length of the reflective electrode strips 21 along the second direction, thereby enhancing the coupling effect.

[0065] In other embodiments, in each measurement group, one reflective electrode strip 21 may correspond to one or more reflective electrode strips 21.

[0066] In other embodiments, the capacitive displacement sensor 1 may also include two or more measurement groups, selected according to actual needs. For example, there is one receiving electrode 12 and four transmitting electrode groups 101. Two transmitting electrode groups 101 are located on one side of the receiving electrode 12 and are arranged side by side along a first direction or a second direction, while the other two transmitting electrode groups 101 are located on the other side of the receiving electrode 12 and are arranged side by side along a first direction or a second direction.

[0067] In some embodiments, in the same measurement group, in the first direction, the width of the emitting electrode 11 is equal to the width of the reflective electrode strip 21, and the plurality of emitting electrodes 11 in the emitting electrode array 10 are arranged periodically with a first pitch L1; each emitting electrode array 10 corresponds to at least one reflective electrode strip 21; the reflective electrode strip 21 corresponding to each emitting electrode array 10 constitutes a reflective electrode group 22; when the reflective electrode group 22 of the same measurement group includes a plurality of reflective electrode strips 21, the reflective electrode strips 21 are arranged periodically with a second pitch L2, and the second pitch L2 is an integer multiple of the corresponding first pitch L1.

[0068] The first pitch L1 is the center-to-center distance between two adjacent emitter electrodes 11 in the same emitter electrode array 10 in the measurement direction. The first pitch L1 can also be called the grid pitch.

[0069] For example, in each emitter electrode group 101, the emitter electrodes 11 are all of the same size and shape, and the emitter electrodes 11 in the same emitter electrode array 10 are arranged at equal intervals. 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 L1 is twice the spacing between adjacent emitter electrodes 11.

[0070] 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.

[0071] By periodically arranging and oriented the reflective electrode strips 21, the capacitive coupling efficiency can be effectively improved, enabling a more precise correspondence between displacement changes and capacitance changes.

[0072] The equal width design of the reflective electrode strip 21 and the emitting electrode 11 helps to maintain the stability of capacitive coupling.

[0073] When the reflective electrode group 22 includes multiple reflective electrode strips 21, the multiple relationship between the second pitch L2 and the first pitch L1 can achieve 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 transmitting electrode array 10 and the reflective electrode strips 21.

[0074] For example, the second pitch L2 is greater than the first pitch L1, which can reduce the difficulty of fabricating the reflective electrode strip 21.

[0075] In some embodiments, there are multiple emitting electrode groups 101, and the capacitive grating displacement sensor 1 further includes a control circuit (not shown). The control circuit is configured to control each emitting electrode group 101 to work independently. In each measurement group, the reflective electrode strips 21 at the same position in each reflective electrode group 22 are defined as second references. In the first direction, the offset of each second reference relative to the corresponding first reference forms a sequence, and the non-zero term with the smallest absolute value in each sequence is defined as a reference term. The reference terms of each measurement group are different from each other.

[0076] When a measurement group is selected for measurement, the control circuit controls the corresponding transmitting electrode group 101 to operate in order to reduce interference between signals.

[0077] The reference parameters determine the measurement accuracy of the measurement set.

[0078] For example, such as Figure 3As shown, the following example illustrates a different measurement group: one emission electrode group 101 includes four emission electrode arrays 10, and another emission electrode group 101 includes two emission electrode groups 101. In the first measurement group, each emission electrode array 10 corresponds to two reflective electrode strips 21, and the overlap area between the two reflective electrode strips 21 and their respective corresponding emission electrode 11 is the same. That is, the reflective electrode group 22 of the first measurement group includes two reflective electrode strips 21. In the second measurement group, each emission electrode array 10 corresponds to one reflective electrode strip 21. That is, the reflective electrode group 22 of the second measurement group includes one reflective electrode strip 21. In the first measurement group, the reflective electrode strips 21 in one reflective electrode group 22 are completely overlapped with the corresponding emitting electrode 11. The reflective electrode strips 21 in another reflective electrode group 22 are located between the emitting electrodes 11. Taking the first emitting electrode 11 in each emitting electrode array 10 as the first reference and the first reflective electrode strip 21 in the reflective electrode group 22 as the second reference, the sequence includes 0 and L1 / 2. Taking the second reflective electrode strip 21 in the reflective electrode group 22 as the second reference, the sequence includes L2 and L2+L1 / 2. The reference term in the first measurement group is L1 / 2, meaning the measurement accuracy of the first measurement group is L1 / 2. In the second measurement group, the offsets of each reflective electrode 20 from the first emitting electrode 11 in the corresponding emitting electrode array 10 are 0, L1 / 4, L1 / 2, and 3L1 / 4, respectively. The reference term is L1 / 4, meaning the measurement accuracy of the second measurement group is L1 / 4.

[0079] Please see Figures 7 to 9 , Figure 7 This is a schematic diagram of the structure of a first embodiment of a measurement group provided in this application. Figure 8 This is a schematic diagram of the structure of a second embodiment of a measurement group provided in this application. Figure 9 This is a schematic diagram of the structure of a third embodiment of a measurement group provided in this application.

[0080] like Figure 7 As shown, in some embodiments, in the measurement group, the transmitting electrode array 10 is arranged periodically with a third pitch L3, the third pitch L3 being n times the corresponding first pitch L1, and n being an integer. In the first direction, the center distance between any two adjacent reflecting electrode groups 22 is greater than n times the first pitch L1 and less than n+1 times the first pitch L1.

[0081] Each emission electrode array 10 in a single measurement group has the same structure.

[0082] For example, in the first direction, the center-to-center distance between any two adjacent reflective electrode groups 22 is equal and is nL+L1 / 4.

[0083] In other embodiments, such as Figure 8As shown, in the first direction, the center distance between any two adjacent reflective electrode groups 22 may not be equal.

[0084] By limiting the center distance between any two adjacent reflective electrode groups 22 to be greater than n times the first pitch L1 and less than n+1 times the first pitch L1, the absolute value of the offset of the second reference relative to the corresponding first reference can be controlled within the length of the first pitch L1, thereby maximizing the range and minimizing the number of emitting electrodes 11 in the emitting electrode array 10.

[0085] like Figure 9 As shown, in some other embodiments, in the measurement group, the reflective electrode group 22 is arranged periodically along the first direction at a fourth pitch L4, where the fourth pitch L4 is m times the corresponding first pitch L1, and m is an integer. In the first direction, the center distance between any adjacent emitting electrode array 10 is greater than m-1 times the first pitch L1 and less than m times the first pitch L1.

[0086] Each emission electrode array 10 in a single measurement group has the same structure.

[0087] For example, in the first direction, the center-to-center spacing between any adjacent emitting electrode arrays 10 is equal and is mL-L1 / 4.

[0088] By limiting the center spacing between any two adjacent emitter electrode arrays 10 to be greater than m-1 times the first pitch L1 and less than m times the first pitch L1, the absolute value of the offset of the second reference relative to the corresponding first reference can be controlled within the length of the first pitch L1, thereby maximizing the range and minimizing the number of emitter electrodes 11 in the emitter electrode array 10.

[0089] In other embodiments, the center-to-center spacing between any adjacent emitter electrode arrays 10 may be unequal.

[0090] In other embodiments, the center-to-center spacing between any adjacent emitting electrode arrays 10 may be unequal, and the center-to-center spacing between any adjacent reflective electrode groups 22 may be unequal.

[0091] In some embodiments, in at least one measurement group, in a first direction, the offset of each second reference relative to the corresponding first reference forms an arithmetic sequence, and the tolerance of the arithmetic sequence is determined by the ratio of the corresponding first pitch L1 to the total number of the emission electrode arrays 10 of the corresponding emission electrode group 101.

[0092] The offset can be positive or negative.

[0093] In a single measurement group, the absolute value of the tolerance of the arithmetic sequence is the ratio of the value of the first pitch L1 to the total number of the corresponding transmitting electrode array 10.

[0094] For example, such as Figure 3 and Figure 7 As shown, taking the second measurement group as an example, the first emission electrode 11 in each emission electrode array 10 is taken as the first reference, and the arithmetic sequence formed by the offset of each second reference relative to the corresponding first reference includes 0, L1 / 4, L1 / 2, and 3L1 / 4 in sequence.

[0095] Please see Figure 1 , Figure 10 and Figure 11 , Figure 10 This is a schematic diagram of the equivalent circuit between the first gate plate and the second gate plate provided in an embodiment of this application. Figure 11 for Figure 10 A schematic diagram showing the coupling capacitance-displacement relationship between each emitting electrode array and the reflecting electrode.

[0096] In some embodiments, in each measurement group, the phase of the excitation signal of each transmitting electrode array 10 is uniformly distributed within a preset period.

[0097] For example, a preset period is π.

[0098] 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... Figure 1 The phase difference between the excitation signals of the four transmitting electrode arrays 10 in the measurement group is π / 4. This distribution method, by uniformly dividing the phase difference into a preset period, makes the excitation signals of each transmitting electrode array 10 form an equal angular interval on the time axis.

[0099] In other embodiments, a preset period may be other values.

[0100] For example, multiple signal sources are used to generate sine or cosine waves with a fixed phase difference. For instance, the signal sources are voltage sources.

[0101] For example, the number of signal sources is the same as the number of transmitting electrode arrays 10.

[0102] In other embodiments, excitation signals with specific phase relationships can also be generated through digital signal processing.

[0103] Each transmitting electrode array 10 forms a coupling capacitor with its corresponding 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 L1 / 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.

[0104] When the displacement is a non-zero integer multiple of L1, 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.

[0105] 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.

[0106] Please see Figure 12 , Figure 12 This is a schematic diagram of the sixth embodiment of the capacitive displacement sensor provided in this application.

[0107] This application also provides a capacitive grating displacement sensor 1. 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 110 and a plurality of emitting electrode arrays 10, each emitting electrode array 10 including a plurality of emitting electrodes 11 arranged periodically along a preset direction at a first pitch L1; the second grating plate 200 includes a second stage 210 and a reflective electrode 20; the reflective electrode 20 includes a reflective electrode strip 21; wherein the emitting electrode arrays 10 are adjustablely disposed on the first stage 110, and / or the reflective electrode strips 21 are adjustablely disposed on the second stage 210; in the preset direction, taking the emitting electrode 11 at the same position in each emitting electrode array 10 as a first reference, the offset of each reflective electrode strip 21 relative to the corresponding first reference is not equal, and the offset is adjustable.

[0108] By making the offsets of each reflective electrode strip 21 relative to the corresponding first reference unequal, the pitch limited by the manufacturing process is dispersed into multiple offsets, thereby overcoming the physical limitations of the 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 reflective electrode strips 21 allows for adjustment of the offsets between the emitting electrode array 10 and the 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.

[0109] The number of emitter electrodes 11 in each emitter electrode array 10 can be the same or different. There are no strict restrictions here, and the selection can be made according to actual needs.

[0110] The preset direction is the direction of a linear vector. The preset direction is parallel to the measurement direction. The preset direction is the first direction.

[0111] During the measurement process, the first grid plate 100 and the second grid plate 200 have relative displacement along the measurement direction.

[0112] One of the first grid plate 100 and the second grid plate 200 is a fixed grid, and the other is a moving grid.

[0113] In some embodiments, the first grid plate 100 further includes a plurality of first substrates 14, each first substrate 14 being equipped with an emitting electrode array 10. The offset is adjusted by adjusting the relative displacement between the first substrate 14 and the first stage 110 along a preset direction. In the preset direction, the width of the emitting electrode 11 is equal to the width of the corresponding reflective electrode strip 21.

[0114] 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.

[0115] 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 corresponding reflective electrode 20.

[0116] This application does not limit the materials of the connecting bridge 13 and the emitting electrode 11; they can be selected according to actual needs. For example, the materials of the connecting bridge 13 and the emitting electrode 11 can be the same or different.

[0117] In some embodiments, the first grid plate 100 further includes a receiving electrode 12 extending along a preset direction and disposed on the first stage 110. In a direction perpendicular to the plate surface of the first grid plate 100, the reflecting electrode 20 partially overlaps with the corresponding receiving electrode 12.

[0118] The transmitting electrode array 10 is located on the side of the receiving electrode 12 along the second direction, and the preset direction is perpendicular to the second direction.

[0119] The emitting electrode array 10 is disposed on the first substrate 14, which facilitates the adjustment of the relative position of the emitting electrode array 10 on the first stage 110; and the first substrate 14 supports the emitting electrode array 10, which can also prevent deformation of the emitting electrode array 10 from causing inaccurate measurements. In addition, compared with fabricating the emitting electrode array 10 as a whole on the first stage 110, this embodiment adjusts the offset by adjusting the relative displacement of the first substrate 14 and the first stage 110 along a preset direction, so that the positioning of each emitting electrode array 10 is more precise and the measurement is more accurate.

[0120] The equal width design of the emitting electrode 11 and the reflecting electrode strip 21 facilitates the adjustment of measurement accuracy.

[0121] For example, the first base 14 is rectangular to facilitate positioning.

[0122] For example, a positioning mark may be provided on the first base 14 to facilitate the positioning of the first base 14.

[0123] In other embodiments, the first base 14 can be of other shapes, which are not limited here and can be selected according to actual needs.

[0124] In some embodiments, the first base 14 is slidably connected to the first stage 110; or, the first base 14 is detachably disposed on the first stage 110 to enable replacement of the first base 14.

[0125] In one specific embodiment, the first base 14 is slidably connected to the first stage 110, and the first base 14 can slide relative to the first stage 110 at least along a preset direction. For example, the first base 14 can slide along the preset direction, and can also slide along a second direction (…). Figure 12 (Not shown) Sliding allows the first stage 110 to accommodate more of the first substrate 14, thereby enabling greater adjustment of measurement accuracy. The second direction is perpendicular to the first direction.

[0126] For example, a groove or slide can be provided on the first platform 110, and the first base 14 is assembled in the groove or slide to limit the position of the first base 14.

[0127] In another specific embodiment, the first base 14 is detachably disposed on the first platform 110 to enable replacement of the first base 14. The first base 14 can be connected to the first platform 110 by means of snap-fit, plug-in, magnetic attraction or threaded connection.

[0128] For example, multiple emission electrode groups (not shown) can be designed, each including multiple emission electrode arrays 10. Each emission electrode group corresponds to a measurement accuracy, and the corresponding emission electrode group can be directly replaced according to the required accuracy. That is, the assembly position of each emission electrode group on the first stage 110 is a preset position, thereby simplifying the assembly.

[0129] For example, multiple emission electrode arrays 10 can be designed, and the emission electrode arrays 10 can be combined and assembled according to the required measurement accuracy. That is, the structures of the emission electrode arrays 10 assembled on the first stage 110 can be the same or different.

[0130] In some embodiments, the first stage 110 has a first assembly scale 15 extending along a preset direction, and the mounting position of the first substrate 14 is determined based on the first assembly scale 15; the line width and line spacing of the first assembly scale 15 are both equal to the width of the emitting electrode 11.

[0131] There are no restrictions on the pattern of the first assembly scale 15 here; it can be selected according to actual needs.

[0132] The first substrate 14 can be positioned using precision instruments such as microscopes based on the first assembly scale 15, which can improve positioning accuracy and measurement accuracy.

[0133] Please see Figures 12 to 14 , Figure 13 This is a schematic diagram of the structure of one embodiment of the second grid plate provided in this application. Figure 14 This is a schematic diagram of the seventh embodiment of the capacitive displacement sensor provided in this application.

[0134] In other embodiments, each emitting electrode array 10 corresponds to at least one reflective electrode strip 21; the reflective electrode strip 21 corresponding to each emitting electrode array 10 constitutes a reflective electrode group 22; the second grid plate 200 also includes a second substrate 201, and a reflective electrode group 22 is mounted on each second substrate 201. The offset is adjusted by adjusting the relative displacement between the second substrate 201 and the second stage 210 along a preset direction; when there are multiple reflective electrode strips 21 in the reflective electrode group 22, the reflective electrode strips 21 are arranged periodically with a second pitch L2, and the second pitch L2 is an integer multiple of the first pitch L1.

[0135] When each reflective electrode group 22 includes a reflective electrode strip 21, in a preset direction, with the emitting electrode 11 at the same position in each emitting electrode array 10 as the first reference, the offset of each reflective electrode strip 21 relative to the corresponding first reference is not equal.

[0136] like Figure 14As shown, when each reflective electrode group 22 includes multiple reflective electrode strips 21, the reflective electrode strips 21 are arranged periodically at a second pitch L2, and the second pitch L2 is an integer multiple of the first pitch L1, so that the overlap area between each reflective electrode strip 21 and the corresponding emitting electrode 11 in the reflective electrode group 22 is the same, which enhances the coupling effect while reducing signal interference between reflective electrode strips 21. In addition, compared with fabricating the reflective electrode 20 on the second stage 210 as a whole, this embodiment adjusts the offset by adjusting the relative displacement of the second substrate 201 and the second stage 210 along a preset direction, so that the positioning of each reflective electrode strip 21 is more precise and the measurement is more accurate.

[0137] The reflective electrode strips 21 of the second substrate 201 are interconnected.

[0138] For example, such as Figure 13 As shown, the reflective electrode 20 also includes a reflective electrode block 23 disposed on the second stage 210, and the reflective electrode group 22 on the second substrate 201 mounted on the second stage 210 is electrically connected to the reflective electrode block 23.

[0139] The reflective electrode block 23 extends along a preset direction to facilitate electrical connection between each reflective electrode group 22 and the reflective electrode block 23.

[0140] For example, the reflective electrode 20 is partially overlapped with the receiving electrode 12 via the reflective electrode block 23. That is, in the direction perpendicular to the plate surface of the first grid plate 100, the reflective electrode block 23 and the receiving electrode 12 are at least partially overlapped.

[0141] The second base 201 and the second stage 210 can be slidably connected or detachably connected. This will not be elaborated on here. Please refer to the connection between the first base 14 and the first stage 110.

[0142] The reflective electrode groups 22 can be arranged periodically or non-periodically, depending on the actual needs.

[0143] In other embodiments, the capacitive displacement sensor 1 includes the first substrate 14 and the second substrate 201 described above, such that both the emitting electrode array 10 and the reflecting electrode strip 21 are adjustable.

[0144] In some embodiments, the second stage 210 has a second assembly scale 24 extending along a preset direction, and the mounting position of the second substrate 201 is determined based on the second assembly scale 24; the line width and line spacing of the second assembly scale 24 are both equal to the width of the reflective electrode strip 21.

[0145] The second substrate 201 can be positioned using precision instruments such as microscopes based on the second assembly scale 24, which can improve positioning accuracy and measurement accuracy.

[0146] There are no restrictions on the pattern of the second assembly scale 24 here; it can be selected according to actual needs.

[0147] Please see Figures 15 to 18 , Figure 15 This is a schematic diagram of the structure of the emitting electrode array, the reflecting electrode strip, and the first assembly scale provided in the first embodiment of this application. Figure 16 This is a schematic diagram of the structure of the transmitting electrode array, the reflecting electrode strip, and the first assembly scale provided in the second embodiment of this application. Figure 17 This is a schematic diagram of the structure of the transmitting electrode array, the reflecting electrode strip, and the first assembly scale provided in the third embodiment of this application. Figure 18 This is a schematic diagram of the structure of the transmitting electrode array, the reflecting electrode strip, and the first assembly scale provided in the fourth embodiment of this application.

[0148] In some embodiments, each reflective electrode strip 21 corresponding to each emitting electrode array 10 constitutes a reflective electrode group 22; the emitting electrode array 10 is arranged periodically with a third pitch L3; the third pitch L3 is n times the first pitch L1, where n is an integer; in a preset direction, the center distance between any adjacent reflective electrode groups 22 is greater than n times the first pitch L1 and less than n+1 times the first pitch L1.

[0149] Each emitter electrode array 10 has the same structure, and each emitter electrode group 101 has the same structure.

[0150] For example, such as Figure 15 As shown, each emitting electrode group 101 includes one emitting electrode 11 strips, and the center-to-center distance between any two adjacent reflective electrode strips 21 is equal and is nL1+L1 / 4. Specifically, taking the first emitting electrode 11 in each emitting electrode array 10 as the first reference, the offset of each reflective electrode strip 21 relative to the first reference in a preset direction is 0, L1 / 4, L1 / 2, and 3L1 / 4, respectively.

[0151] In other embodiments, the center-to-center spacing between the reflective electrode groups 22 may be unequal, and no particular restrictions are imposed here. For example, as Figure 16 As shown, taking the first emission electrode 11 in each emission electrode array 10 as the first reference, in a preset direction, the offset of each reflection electrode strip 21 relative to the first reference is 0, L1 / 8, L1 / 2, 3L1 / 4 respectively, and the center distance between two adjacent emission electrode strips 11 is nL1+L1 / 8, nL1+3L1 / 8, nL1+L1 / 4 respectively.

[0152] By limiting the center distance between any two adjacent reflective electrode groups 22 to be greater than n times the first pitch L1 and less than n+1 times the first pitch L1, the absolute value of the offset of the second reference relative to the corresponding first reference can be controlled within the length of the first pitch L1, thereby maximizing the range and minimizing the number of emitting electrodes 11 in the emitting electrode array 10.

[0153] In other embodiments, each reflective electrode strip 21 corresponding to each emitting electrode array 10 constitutes a reflective electrode group 22; the reflective electrode group 22 is arranged periodically along a preset direction at a fourth pitch L4; the fourth pitch L4 is m times the first pitch L1, where m is an integer; in the preset direction, the center distance between any adjacent emitting electrode arrays 10 is greater than m-1 times the first pitch L1 and less than m times the first pitch L1.

[0154] Each emitter electrode array 10 has the same structure, and each emitter electrode group 101 has the same structure.

[0155] For example, such as Figure 17 As shown, each emitting electrode array 101 includes one emitting electrode 11 strips. The center-to-center distance between any two adjacent emitting electrode arrays 10 is equal and is mL1-L1 / 4. Specifically, taking the first emitting electrode 11 in the emitting electrode array 10 as the first reference, the offset of each reflective electrode strip 21 relative to the first reference in a preset direction is 0, L1 / 4, L1 / 2, and 3L1 / 4, respectively.

[0156] In other embodiments, the center-to-center spacing between the various emitting electrode arrays 10 may be unequal, and no further restrictions are imposed here.

[0157] By limiting the center spacing between any two adjacent emitter electrode arrays 10 to be greater than m-1 times the first pitch L1 and less than m times the first pitch L1, the absolute value of the offset of the second reference relative to the corresponding first reference can be controlled within the length of the first pitch L1, thereby maximizing the range and minimizing the number of emitter electrodes 11 in the emitter electrode array 10.

[0158] In other embodiments, the emitting electrode arrays 10 may be spaced at unequal intervals, and the reflecting electrode groups 22 may be spaced at unequal intervals.

[0159] In some embodiments, such as Figure 16 As shown, each reflective electrode strip 21 corresponding to each emitting electrode array 10 constitutes a reflective electrode group 22; the reflective electrode strips 21 at the same position in each reflective electrode group 22 are defined as the second reference; in a preset direction, the offset of each second reference relative to the corresponding first reference constitutes an arithmetic sequence, and the tolerance of the arithmetic sequence is determined by the ratio of the first pitch L1 to the total number of emitting electrode arrays 10.

[0160] For example, taking the first emitting electrode 11 in the emitting electrode array 10 as the first reference, the offsets of each reflective electrode strip 21 relative to the first reference in a preset direction are 0, L1 / 4, L1 / 2, and 3L1 / 4, respectively.

[0161] In other embodiments, such as Figure 18 As shown, in the preset direction, the sequence formed by the offsets of each second reference relative to the corresponding first reference can be a non-arithmetic sequence.

[0162] In other embodiments, in the plurality of sequentially arranged reflective electrode arrays, the offset of each second reference relative to the first reference can be a monotonic sequence or a non-monotonic sequence. For example, as Figure 18 As shown, with the first emitter 11 in the emitter electrode array 10 as the first reference, the offsets of each second reference arranged in sequence relative to the first reference are 0, 3L1 / 2, 3L1 / 4, and L1 / 4, respectively. This sequence is a non-monotonic sequence.

[0163] In some embodiments, such as Figures 10 to 12 As shown, the phase of the excitation signal of each transmitting electrode array 10 is uniformly distributed within a preset period.

[0164] For example, a preset period is π.

[0165] 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. This distribution method achieves this by uniformly dividing the preset period by phase differences, so that the excitation signals of each transmitting electrode array 10 form equiangular intervals on the time axis.

[0166] In other embodiments, a preset period may be other values.

[0167] For example, multiple signal sources are used to generate sine waves or cosine waves with a fixed phase difference.

[0168] For example, the number of signal sources is the same as the number of transmitting electrode arrays 10.

[0169] In other embodiments, excitation signals with specific phase relationships can also be generated through digital signal processing.

[0170] For example, each transmitting electrode array 10 forms a coupling capacitor with its corresponding 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 at displacement 0, to C1=c / 2, C2=c, C3=c / 2, C4=0 at displacement L1 / 4). Simultaneously, the excitation signals of each transmitting electrode array 10 have a specific phase difference, causing the signals transmitted to the receiving electrode 12 through each coupling capacitor to have different phases, not only modulated by the capacitance value but also modulated by the amplitude. 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, thus achieving accurate displacement detection.

[0171] In some embodiments, the capacitive grating displacement sensor 1 further includes a phase identification circuit (not shown) and a counting circuit (not shown).

[0172] 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.

[0173] 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.

[0174] 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 L1, and the induced signal completes one cycle. The cycles (or pulses) of the induced signal are continuously counted to accumulate the total relative displacement.

[0175] 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.

[0176] Please see Figure 19 , Figure 19 This is a schematic diagram of an embodiment of the capacitive displacement sensor provided in this application.

[0177] 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.

[0178] For example, the phase identification circuit and the counting circuit can be integrated into the printed circuit board 400.

[0179] 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.

[0180] 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 first stage and a plurality of emission electrode arrays, each of the emission electrode arrays including a plurality of emission electrodes arranged in a predetermined direction at a first pitch period. The second grid plate includes a second stage and a reflective electrode; the reflective electrode includes a reflective electrode strip. The emitting electrode array is adjustablely disposed on the first stage, and / or the reflecting electrode strip is adjustablely disposed on the second stage; In the preset direction, taking the emitting electrodes at the same position in each of the emitting electrode arrays as a first reference, the offsets of each of the reflective electrode strips relative to the corresponding first reference are not equal, and the offsets are adjustable.

2. The capacitive displacement sensor according to claim 1, characterized in that, The first grid plate also includes a plurality of first substrates, each of which is equipped with an emission electrode array. The offset is adjusted by adjusting the relative displacement between the first substrate and the first stage along the preset direction. In the preset direction, the width of the emitting electrode is equal to the width of the corresponding reflective electrode strip.

3. The capacitive displacement sensor according to claim 2, characterized in that, The first substrate is slidably connected to the first platform; or, the first substrate is detachably disposed on the first platform to enable replacement of the first substrate.

4. The capacitive displacement sensor according to claim 2, characterized in that, The first stage has a first assembly scale extending along the preset direction, and the mounting position of the first substrate is determined based on the first assembly scale; the line width and line spacing of the first assembly scale are both equal to the width of the emitting electrode.

5. The capacitive displacement sensor according to claim 1, characterized in that, Each of the emitting electrode arrays corresponds to at least one of the reflecting electrode strips; the reflecting electrode strips corresponding to each emitting electrode array constitute a reflecting electrode group; The second grid plate also includes a second substrate, and each second substrate is equipped with a set of the reflective electrodes. The offset is adjusted by adjusting the relative displacement between the second substrate and the second stage along the preset direction. When there are multiple reflective electrode strips in the reflective electrode group, the reflective electrode strips are arranged in a second pitch period, and the second pitch is an integer multiple of the first pitch.

6. The capacitive displacement sensor according to claim 5, characterized in that, The second stage has a second assembly scale extending along the preset direction, and the installation position of the second substrate is determined based on the second assembly scale; the line width and line spacing of the second assembly scale are both equal to the width of the reflective electrode strip.

7. The capacitive displacement sensor according to claim 1, characterized in that, Each of the emitting electrode arrays corresponds to a reflective electrode strip that constitutes a reflective electrode group; the emitting electrode arrays are arranged in a third pitch period; the third pitch is n times the first pitch, where n is an integer; in the preset direction, the center distance between any adjacent reflective electrode groups is greater than n times the first pitch and less than n+1 times the first pitch.

8. The capacitive displacement sensor according to claim 1, characterized in that, Each of the emitting electrode arrays corresponds to a reflective electrode strip that constitutes a reflective electrode group; the reflective electrode group is arranged periodically along the preset direction with a fourth pitch; the fourth pitch is m times the first pitch, where m is an integer; in the preset direction, the center-to-center distance between any two adjacent emitting electrode arrays is greater than m-1 times the first pitch and less than m times the first pitch.

9. The capacitive displacement sensor according to claim 1, characterized in that, The reflective electrode strips corresponding to each of the aforementioned emission electrode arrays constitute a reflective electrode group; the reflective electrode strips at the same position in each of the aforementioned reflective electrode groups are defined as a second reference; In the preset direction, the offsets of each second reference relative to the corresponding first reference form an arithmetic sequence, and the tolerance of the arithmetic sequence is determined by the ratio of the first pitch to the total number of the transmitting electrode array.

10. 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.

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