Capacitive grating displacement sensor of electrode structure

Abstract

The utility model relates to the technical field of displacement sensors, in particular to a capacitive displacement sensor with an electrode structure, which comprises a transmitting electrode, a receiving electrode and a capacitive measuring circuit. According to the utility model, the emission electrode is connected with the capacitive gate measuring circuit in a double-side lead mode, so that the manufacturing difficulty and cost of the high-precision capacitive gate sensor are reduced, the space utilization rate of the sensor is improved, and the miniaturization of the high-precision capacitive gate sensor is facilitated; the arrangement positions of the transmitting electrode and the receiving electrode can be suitable for a mechanical structure of an existing sensor, high compatibility is achieved, especially in the application of a small-range sensor, the transmitting electrode and the receiving electrode are oppositely arranged, secondary coupling is not needed, displacement signals are enhanced, and the measurement precision of the sensor is improved.

Description

Technical Field

[0001] This utility model relates to the field of displacement sensor technology, and in particular to a capacitive grating displacement sensor with an electrode structure. Background Technology

[0002] Capacitive grating displacement sensors are capacitive sensors based on the variable area working principle. Due to their simple structure and low cost, they are widely used in various displacement detection devices. Existing capacitive grating displacement sensors are all reflective clustered electrode structures, including parallel but non-contact moving and fixed electrode plates. The moving electrode plate has a transmitting electrode and a receiving electrode, and the fixed electrode plate has a reflecting electrode. The capacitive grating signal is coupled to the reflecting electrode through the transmitting electrode, and then coupled to the receiving electrode again by the reflecting electrode. Finally, the displacement signal is processed by the capacitive grating measurement circuit and then sent out to display the displacement data. The transmitting and receiving electrodes are a single unit, placed side by side perpendicular to the displacement direction. The receiving electrode is placed above the transmitting electrode. The transmitting electrode consists of multiple transmitting gratings arranged periodically along the displacement direction. The transmitting gratings are led out from one side below and connected to the capacitive grating measurement circuit through metallized via pads.

[0003] High-precision capacitive grating displacement sensors primarily aim to improve sensor resolution. The periodic pitch of the emitting electrodes determines this resolution; therefore, reducing the emission electrode pitch is necessary to increase resolution. However, in the aforementioned sensor electrode structure, reducing the emission electrode pitch results in a denser emission grid within the emission electrodes. This makes it difficult, due to circuit board manufacturing limitations, to fabricate metallized via pads that match the lead spacing. Furthermore, because the emission grid can only be electrically connected to the capacitive grating measurement circuit from one side, existing high-precision capacitive grating displacement sensors often use a single-sided divergent lead configuration to increase the distance between the emission grid leads, such as... Figure 7 As shown, this sensor is difficult and costly to manufacture, and the area of ​​the lead wire portion is much larger than the area of ​​the emitting electrode, resulting in low space utilization and hindering the miniaturization of high-precision sensors. Furthermore, existing technology (200720080734.0) "Grid Bar Plate of Capacitive Grating Sensor" proposes a scheme of spaced-out emitting grid bars. Although this eliminates the need for divergent leads, it inserts shielding electrodes into the originally continuously arranged emitting electrodes, halving the effective electrode area of ​​the emitting electrodes. This weakens the displacement signal under the same sensor structure, reducing the sensor's measurement accuracy. Utility Model Content

[0004] The purpose of this invention is to provide a capacitive grating displacement sensor with an electrode structure, which aims to solve the problems of high manufacturing difficulty, high cost, low space utilization and low measurement accuracy of existing high-precision capacitive grating displacement sensors.

[0005] To achieve the above objectives, this utility model provides a capacitive grating displacement sensor with an electrode structure, including a transmitting electrode 1, a receiving electrode 2, and a capacitive grating measurement circuit 3. The transmitting electrode 1 and the receiving electrode 2 are placed separately, which can form a through-beam electrode structure and a reflective electrode structure. The transmitting electrode 1 is composed of a plurality of periodically arranged transmitting gratings 101 along the displacement direction, and is electrically connected to the capacitive grating measurement circuit 3 by means of double-sided leads. Specifically, the transmitting gratings 101 alternately lead wires 102 to both sides, and the wires 102 are connected to via pads 103. The via pads 103 are electrically connected to the capacitive grating measurement circuit 3.

[0006] Specifically, the through-beam electrode structure consists of a receiving electrode 2 composed of a plurality of periodically arranged receiving grids 201 arranged along the displacement direction. The plurality of receiving grids 201 are electrically connected to each other and electrically connected to the capacitive grid measurement circuit 3. The arrangement period of the receiving grids 201 and the transmitting grids 101 is consistent. The transmitting electrode 1 is placed parallel to the receiving electrode 2 and moves relative to each other along the displacement direction.

[0007] In addition, the reflective electrode structure specifically includes a reflective electrode 4, which is composed of a plurality of periodically arranged reflective gratings 401 arranged along the displacement direction. The plurality of reflective gratings 401 are electrically connected to each other, and the arrangement period of the reflective gratings 401 and the transmitting grating 101 is consistent. The receiving electrode 2 is electrically connected to the capacitive grating measurement circuit 3. The transmitting electrode 1 and the receiving electrode 2 are arranged sequentially along the displacement direction, and the reflective electrode 4 is placed parallel to and opposite to the transmitting electrode 1 and the receiving electrode 2, and moves along the displacement direction.

[0008] • The beneficial effects of this utility model:

[0009] 1. The emitter electrode is electrically connected to the capacitive grating measurement circuit by means of double-sided leads, so that its gate density can be adapted to the circuit board process, which reduces the manufacturing difficulty and cost of high-precision capacitive grating sensors, improves the space utilization of the sensor, and is conducive to the miniaturization of high-precision capacitive grating sensors.

[0010] 2. The separate placement of the transmitting and receiving electrodes allows its reflective electrode structure to be adapted to existing sensor mechanical structures, resulting in high compatibility. Furthermore, its through-beam electrode structure, in applications of high-precision capacitive grating sensors with small ranges, such as dial indicators, micrometers, and quick-measuring micrometers, allows the receiving electrode to directly couple the signal with the transmitting electrode, eliminating the need for secondary coupling via a reflective electrode. This enhances the displacement signal and improves the sensor's measurement accuracy. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0012] Figure 1 This is a schematic diagram of the transmitting electrode structure of a capacitive displacement sensor according to the present invention.

[0013] Figure 2 This is a schematic diagram of the absolute type emission electrode structure of this utility model.

[0014] Figure 3 This is a schematic diagram of the electrode structure of Embodiment 1 of this utility model.

[0015] Figure 4 This is a schematic diagram of the electrode structure in Embodiment 2 of this utility model.

[0016] Figure 5 This is a schematic diagram of the electrode structure in Embodiment 3 of this utility model.

[0017] Figure 6 This is a schematic diagram of the electrode structure in Embodiment 4 of this utility model.

[0018] Figure 7 This is a schematic diagram of the electrode structure of an existing high-precision capacitive displacement sensor.

[0019] In the diagram: 1. Emitter electrode, 2. Receiver electrode, 3. Capacitive grid measurement circuit, 4. Reflector electrode, 5. Moving electrode plate, 6. Fixed electrode plate, 101. Emitter grid, 102. Wire, 103. Via pad, 201. Receiver grid, 401. Reflector grid, A1. Absolute emitter electrode, A2. Absolute receiver electrode, A4. Absolute reflector electrode, D1-1. First emitter electrode, D2-1. Second emitter electrode, D1-2. First receiver electrode, D2-2. Second receiver electrode, D1-4. First reflector electrode, D2-4. Second reflector electrode, D1-101. First emitter grid, D2-101. Second emitter grid, D1-201. First receiver grid, D2-201. Second receiver grid, D1-401. First reflector grid, D2-401. Second reflector grid. Detailed Implementation

[0020] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0021] This invention provides a capacitive grating displacement sensor with an electrode structure, including a transmitting electrode 1, a receiving electrode 2, and a capacitive grating measurement circuit 3. The transmitting electrode 1 has the following structure: Figure 1 As shown, the emitting electrode 1 consists of a series of periodically arranged emitting grids 101 along the displacement direction, and is electrically connected to the capacitive grid measurement circuit 3 using a double-sided lead-in method. Specifically, the emitting grids 101 alternately extend wires 102 to both sides, and the wires 102 are connected to via pads 103. The via pads 103 are electrically connected to the capacitive grid measurement circuit 3. In the figure, the wires 102 and via pads 103 are placed on both sides of the emitting electrode 1, which reduces the arrangement density of the wires 102 and via pads 103 by half. This allows for the placement of larger via pads 103 to meet the requirements of the circuit board manufacturing process, thereby adapting the gate density to the circuit board manufacturing process. This reduces the manufacturing difficulty and cost of high-precision capacitive grid sensors, improves the space utilization of the sensor, and is beneficial for the miniaturization of high-precision capacitive grid sensors.

[0022] Furthermore, retaining the remaining components of the above structure, the only difference is that the aforementioned column of emission grids is centered along the displacement direction and divided into two columns. One column of emission grids D1-101 forms the first emission electrode D1-1, and the other column of emission grids D2-101 forms the second emission electrode D2-1. The periodic pitch of one column of emission grids is then finely adjusted, and the two columns of emission grids are connected by wire 102 to form the absolute emission electrode A1 of this utility model, the structure of which is as follows: Figure 2 As shown.

[0023] Please see Figures 3-6 This utility model provides a capacitive grating displacement sensor with an electrode structure, including a transmitting electrode 1, a receiving electrode 2 and a capacitive grating measurement circuit 3. The transmitting electrode 1 and the receiving electrode 2 are placed separately, which can form a through-beam electrode structure and a reflective electrode structure.

[0024] Example 1:

[0025] The sensor with a through-beam electrode structure provided by this utility model has the following electrode structure: Figure 3 As shown, the transmitting electrode 1 consists of a plurality of periodically arranged transmitting grids 101 along the displacement direction, and is electrically connected to the capacitive grid measurement circuit 3 using double-sided leads; the receiving electrode 2 consists of a plurality of periodically arranged receiving grids 201 along the displacement direction, the plurality of receiving grids 201 are electrically connected to each other, and are also electrically connected to the capacitive grid measurement circuit 3, the arrangement period of the receiving grids 201 and the transmitting grids 101 is consistent. The transmitting electrode 1 and the receiving electrode 2 are placed parallel to each other, respectively on the moving electrode plate 5 and the fixed electrode plate 6, and move relative to each other along the displacement direction.

[0026] In this embodiment, incremental linear displacement sensors with small ranges, such as dial indicators, micrometers, and quick-measuring micrometers, are suitable. Their transmitting electrode 1 and receiving electrode 2 form a coupling capacitor. The displacement signal is directly coupled to the receiving electrode 2 and sent to the capacitive grating measurement circuit 3 for processing. This displacement signal does not require secondary coupling by the reflecting electrode 4, which enhances the displacement signal and improves the measurement accuracy of the sensor.

[0027] Example 2:

[0028] The absolute sensor with a through-beam electrode structure provided by this utility model consists of two sets of incremental sensors from Embodiment 1 placed side by side, and its electrode structure is as follows: Figure 4 As shown, the absolute transmitting electrode A1 and the absolute receiving electrode A2 are respectively placed on the moving electrode plate 5 and the fixed electrode plate 6. The absolute transmitting electrode A1 includes a first transmitting electrode D1-1 and a second transmitting electrode D2-1, and the absolute receiving electrode A2 includes a first receiving electrode D1-2 and a second receiving electrode D2-2. The first transmitting electrode D1-1 and the first receiving electrode D1-2 form one group; the second transmitting electrode D2-1 and the second receiving electrode D2-2 form another group. The arrangement rules of each electrode are the same as those of the sensor in Embodiment 1.

[0029] Example 3:

[0030] The sensor with a reflective electrode structure provided by this utility model also includes a reflective electrode 4, the electrode structure of which is as follows: Figure 5 As shown, the transmitting electrode 1 consists of a plurality of periodically arranged transmitting grids 101 along the displacement direction, and is electrically connected to the capacitive grid measurement circuit 3 by means of double-sided leads; the receiving electrode 2 is electrically connected to the capacitive grid measurement circuit 3; the reflecting electrode 4 consists of a plurality of periodically arranged reflecting grids 401 along the displacement direction, and the plurality of reflecting grids 401 are electrically connected to each other, and the arrangement period of the reflecting grids 401 and the transmitting grids 101 is consistent. The transmitting electrode 1 and the receiving electrode 2 are arranged sequentially along the displacement direction and placed on the fixed electrode plate 6; the reflecting electrode 4 is parallel to and opposite to the transmitting electrode 1 and the receiving electrode 2, placed on the moving electrode plate 5, and moves along the displacement direction.

[0031] In this embodiment, an incremental linear displacement sensor suitable for large ranges is used. Based on the double-sided lead connection of the transmitting electrode 1, its electrode layout has been optimized. The reflecting electrode 4 completely covers the transmitting electrode 1 and the receiving electrode 2. The displacement signal is coupled from the transmitting electrode 1 to a portion of the reflecting grating, then electrically transmitted to another portion of the reflecting grating, then coupled a second time to the receiving electrode 2, and finally sent to the capacitive grating measurement circuit 3 for processing. Figure 7 In contrast, the reflective electrode structure of this embodiment can also be applied to the mechanical structure of existing sensors, exhibiting high compatibility.

[0032] Example 4:

[0033] The absolute sensor with a reflective electrode structure provided by this utility model consists of two sets of incremental sensors from Embodiment 3 placed side by side, and their electrode structures are as follows: Figure 6 As shown, the absolute emitting electrode A1 and the absolute receiving electrode A2 are placed on the moving electrode plate 5; the absolute reflecting electrode A4 is placed on the fixed electrode plate 6; the absolute emitting electrode A1 includes a first emitting electrode D1-1 and a second emitting electrode D2-1, the absolute receiving electrode A2 includes a first receiving electrode D1-2 and a second receiving electrode D2-2, and the absolute reflecting electrode A4 includes a first reflecting electrode D1-4 and a second reflecting electrode D2-4; wherein, the first emitting electrode D1-1, the first receiving electrode D1-2, and the first reflecting electrode D1-4 form a group; the second emitting electrode D2-1, the second receiving electrode D2-2, and the second reflecting electrode D2-4 form a group; the arrangement rule of each electrode is the same as that of the sensor in Embodiment 3.

[0034] The absolute sensor and incremental sensor of this invention can have the same electrode area, and can be installed in the same mechanical structure, which increases the versatility and adaptability of the absolute capacitive grating sensor and accelerates its promotion and application.

[0035] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A capacitive grating displacement sensor with an electrode structure, comprising a transmitting electrode, a receiving electrode, and a capacitive grating measurement circuit, wherein the transmitting electrode and the receiving electrode are placed separately, which can constitute a through-beam electrode structure and a reflective electrode structure; the transmitting electrode is composed of a plurality of periodically arranged transmitting gratings along the displacement direction, characterized in that, The emitter gate is alternately led out with wires to both sides, and the wires are connected to via pads. The via pads are electrically connected to the capacitive gate measurement circuit.

2. The capacitive grating displacement sensor with electrode structure as described in claim 1, characterized in that, The through-beam electrode structure comprises a receiving electrode consisting of a plurality of periodically arranged receiving grids along the displacement direction, wherein the plurality of receiving grids are electrically connected to each other and electrically connected to the capacitive grid measurement circuit, and the arrangement period of the receiving grids and the transmitting grids is consistent. The transmitting electrode and the receiving electrode are placed parallel to each other and move relative to each other along the displacement direction.

3. The capacitive grating displacement sensor with the electrode structure as described in claim 1, characterized in that, The reflective electrode structure further includes a reflective electrode, which is composed of a plurality of periodically arranged reflective gratings along the displacement direction. The plurality of reflective gratings are electrically connected to each other, and the arrangement period of the reflective gratings and the emitting gratings is consistent. The receiving electrode is electrically connected to the capacitive grating measurement circuit; the transmitting electrode and the receiving electrode are arranged sequentially along the displacement direction, and the reflecting electrode is placed parallel to and opposite to the transmitting electrode and the receiving electrode, and moves along the displacement direction.

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