Capacitive proximity sensor electrode and capacitive proximity sensor

Abstract

The embodiment of the utility model provides a capacitive proximity sensor electrode and a capacitive proximity sensor. The capacitive proximity sensor electrode comprises a detection electrode which comprises a detection electrode plate, the detection electrode plate forms the side face of the detection electrode, and the top face and the bottom face of the detection electrode are located in the detection electrode plate; the grounding ring is located on the outer side of the detection electrode, and the grounding ring wraps the side face of the detection electrode; and the shielding film is positioned on the outer side of the grounding ring and wraps the grounding ring. Therefore, on the premise of ensuring the sensitivity, the high shielding performance of metal around the side surface can be realized.

Description

Technical Field

[0001] This application relates to the field of sensors, and more particularly to a capacitive proximity sensor electrode and a capacitive proximity sensor. Background Technology

[0002] A sensor is a detection device that can detect the information being measured. It can transform the detected information into an electrical signal or other required form of information according to certain rules and then output it to meet the requirements of information transmission, processing, storage, display, recording and control.

[0003] Proximity sensors are a general term for non-contact sensors that replace contact-based detection methods such as limit switches, aiming to detect objects without contact. When detecting the movement or presence of an object, proximity sensors can convert this information into electrical signals by utilizing eddy currents generated in the metal body of the object due to electromagnetic induction, or by changes in the capacitance of electrical signals caused by the proximity of the object.

[0004] A capacitive sensor is a conversion device that uses various types of capacitors as sensing elements. It captures the capacitance generated by an object on the copper foil on side A of the detection electrode plate and converts it into an electrical signal. Essentially, it is a capacitor with variable parameters. Capacitive sensors are widely used in the measurement of displacement, angle, vibration, velocity, pressure, composition analysis, and media properties.

[0005] Capacitive proximity sensors detect the approach of an object by measuring the change in capacitance between the object and the sensor. Capacitive proximity sensors can detect objects at relatively long distances and have high sensitivity, capable of detecting extremely small objects or slight changes in proximity. Furthermore, compared to traditional proximity sensors, capacitive proximity sensors can detect not only metallic objects but also other non-metallic objects such as water and plastics, making them widely applicable in scenarios such as liquid level detection, touch control, and object detection.

[0006] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Utility Model Content

[0007] The inventors discovered that when metal approaches the side area of ​​a capacitive proximity sensor head, the capacitance values ​​between the various structures of the head's detection electrodes change significantly, with some structures showing a decreasing capacitance trend, which can easily lead to sensor recognition errors. Adding a suspended copper ring or a grounded copper ring structure to the outer ring of the head's detection electrodes can shield against surrounding metal. However, these structures alone offer limited improvement in eliminating the influence of surrounding metal, still causing significant changes in capacitance values ​​between the head's detection electrodes, leading to product malfunctions. Therefore, improving the shielding performance against surrounding metal to prevent product malfunctions is a problem that needs to be solved.

[0008] To address at least one of the aforementioned technical problems or other similar issues, embodiments of this application provide a capacitive proximity sensor electrode and a capacitive proximity sensor, which can improve the shielding performance against surrounding metal and prevent product malfunctions.

[0009] According to a first aspect of the embodiments of this application, a capacitive proximity sensor electrode is provided, the electrode comprising:

[0010] A detection electrode includes a detection electrode plate forming the side surface of the detection electrode, and the top and bottom surfaces of the detection electrode are located within the detection electrode plate.

[0011] A grounding ring, located outside the detection electrode, and the grounding ring wrapping around the side surface of the detection electrode; and

[0012] A shielding film is located on the outside of the grounding ring and wraps around the grounding ring.

[0013] In some embodiments, the detection electrode is a cylindrical structure, and the grounding ring and the shielding film are respectively arranged around the side; and the detection electrode, the grounding ring and the shielding film are coaxial.

[0014] In some embodiments, the outer diameters of the top and bottom surfaces of the detection electrode are smaller than the outer diameter of the detection electrode plate.

[0015] In some embodiments, the grounding ring protrudes beyond the detection electrode.

[0016] In some embodiments, the grounding ring is a metal ring-shaped component surrounding the side of the detection electrode.

[0017] In some embodiments, the shielding film is a metal ring-shaped component surrounding the grounding ring, and an insulating layer is provided between the shielding film and the grounding ring.

[0018] In some embodiments, the shielding film is not connected to the excitation source or the shielding film is not connected to ground, and the shielding film has a floating potential.

[0019] In some embodiments, the shielding film forms a Faraday cage structure.

[0020] According to a second aspect of the embodiments of this application, a capacitive proximity sensor is provided, the sensor including the capacitive proximity sensor electrodes described in any of the preceding claims.

[0021] One of the beneficial effects of the embodiments of this application is that the outer ring shielding structure of the head detection electrode includes a grounding ring and a shielding film, which can reduce the influence of the surrounding metal on the capacitive proximity sensor, reduce the change in the capacitance value of the detection electrode, and improve the shielding performance against the surrounding metal while ensuring sensitivity.

[0022] Referring to the following description and accompanying drawings, specific implementation methods of the embodiments of this application are disclosed in detail, indicating how the principles of the embodiments of this application can be adopted. It should be understood that the implementation methods of this application are not limited in scope. Within the spirit and scope of the appended claims, the implementation methods of this application include many changes, modifications, and equivalents. Attached Figure Description

[0023] The accompanying drawings, which form part of the specification, are used to provide a further understanding of the embodiments of this application and illustrate the implementation methods of this application, together with the textual description, to explain the principles of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other implementation methods based on these drawings without creative effort. In the drawings:

[0024] Figure 1 This is a schematic diagram of a capacitive proximity sensor electrode according to an embodiment of this application;

[0025] Figure 2 This is a schematic diagram of the detection electrode of a capacitive proximity sensor according to an embodiment of this application;

[0026] Figure 3 This is a schematic diagram of the surrounding metal near the electrodes of a capacitive proximity sensor according to an embodiment of this application. Detailed Implementation

[0027] Referring to the accompanying drawings, the foregoing and other features of the embodiments of this application will become apparent from the following description. Specific embodiments of this application are specifically disclosed in the description and drawings, illustrating partial implementations in which the principles of the embodiments of this application can be adopted. It should be understood that this application is not limited to the described embodiments; rather, the embodiments of this application include all modifications, variations, and equivalents falling within the scope of the appended claims.

[0028] In the embodiments of this application, the terms "first," "second," etc., are used to distinguish different elements by name, but do not indicate the spatial arrangement or chronological order of these elements, and these elements should not be limited by these terms. The term "and / or" includes any one or more of the terms listed in association and all combinations thereof. The terms "comprising," "including," "having," etc., refer to the presence of the stated features, elements, components, or assemblies, but do not exclude the presence or addition of one or more other features, elements, components, or assemblies.

[0029] In the embodiments of this application, the singular forms "a," "the," etc., including the plural forms, should be broadly understood as "a kind" or "a class" rather than limited to the meaning of "an." Furthermore, the term "the" should be understood to include both the singular and plural forms, unless the context explicitly indicates otherwise. Additionally, the term "according to" should be understood as "at least partially based on…," and the term "based on" should be understood as "at least partially based on…," unless the context explicitly indicates otherwise.

[0030] Features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments. The term "comprising / including" as used herein means the presence of a feature, integral, step, or component, but does not exclude the presence or addition of one or more other features, integrals, steps, or components.

[0031] The capacitive proximity sensor described in this application is a high-sensitivity sensor based on the principle of capacitance change, used to detect the presence or absence of an object or changes in distance between the sensor and the object. This sensor can detect various materials non-contactly, including metals, non-metals, liquids, and particulate matter, and is therefore widely used in industrial automation.

[0032] Capacitive proximity sensors operate by detecting changes in capacitance between their sensing electrodes and a nearby object. When an object approaches the sensor, the capacitance between them changes. The sensor captures this change and converts it into an electrical signal output, which can be used to trigger a switch action or send a feedback signal. Because this operation does not rely on mechanical contact, capacitive proximity sensors can operate stably for extended periods without wear.

[0033] For example, capacitive proximity sensors have one or more of the following characteristics: they can detect a variety of materials such as metals, plastics, liquids, wood, and paper, and have wide applicability; they do not require direct contact with the object being measured, reducing wear and lowering maintenance costs; they have high sensitivity; and because there are no mechanical parts involved, capacitive proximity sensors experience almost no wear, and their service life is significantly longer than that of traditional mechanical sensors.

[0034] The capacitive proximity sensor according to embodiments of this application will now be described in detail with reference to the accompanying drawings. It should be understood that the embodiments shown below are merely illustrative and may include more or fewer components.

[0035] This application provides a capacitive proximity sensor, which includes capacitive proximity sensor electrodes.

[0036] Figure 1 This is a schematic diagram of a capacitive proximity sensor electrode according to an embodiment of this application, showing the overall structure of the capacitive proximity sensor electrode, as follows. Figure 1 As shown, the capacitive proximity sensor electrode 100 includes: a detection electrode 101, a grounding ring 102 located outside the detection electrode 101 and covering its side surface, and a shielding film 103 located outside the grounding ring 102 and covering its side surface. The detection electrode 101 includes a detection electrode plate 104. Figure 1 (Not shown), the detection electrode plate 104 forms the side of the detection electrode 101, and the top and bottom surfaces of the detection electrode 101 are located in the detection electrode plate 104.

[0037] Therefore, by designing the outer ring shielding structure of the detection electrode 101 as a grounding ring 102 wrapped with another shielding film 103, high shielding performance against the surrounding metal can be achieved while ensuring sensitivity.

[0038] In some embodiments, the top and bottom surfaces of the detection electrode 101 are located on the same detection electrode plate 104, namely, the A and B surfaces of the detection electrode plate 104. Figure 2 This is a schematic diagram of the detection electrode of a capacitive proximity sensor according to an embodiment of this application, as shown below. Figure 2 As shown, a copper foil 105 is respectively disposed on surface A and surface B of the detection electrode plate 104, and capacitance is detected based on the copper foil 105. For example, the top surface and bottom surface of the detection electrode 101 are located on surface A and surface B of the detection electrode plate 104, and a copper foil 105 is disposed on each of the top and bottom surfaces, thereby constituting a complete detection electrode 101.

[0039] In some embodiments, the detection electrode plate 104 is a PCB board, but this application is not limited thereto.

[0040] In some embodiments, the grounding ring 102 is flush with or protrudes from the detection electrode 101. For example, the grounding ring 102 is flush with the detection electrode 101 above and / or below, but this application is not limited thereto. As another example, when the grounding ring 102 surrounds the detection electrode 101, it protrudes slightly above and / or below the detection electrode 101, but this application is not limited thereto.

[0041] In some embodiments, the grounding ring 102 may cover all or part of the side of the detection electrode 101. For example, the grounding ring 102 may cover the entire area of ​​the side of the detection electrode 101, or only cover the upper half of the side of the detection electrode 101. This application is not limited thereto.

[0042] In some embodiments, the grounding ring 102 partially covers the top and / or bottom surfaces of the detection electrode 101. For example, the grounding ring 102 only covers the outer portion of the top and / or bottom surfaces of the detection electrode 101, and its coverage area is 1 / 10 of the top and / or bottom surfaces of the detection electrode 101. This application is not limited to this.

[0043] In some embodiments, the shielding film 103 may cover all or part of the grounding ring 102. For example, the shielding film 103 may cover the entire area of ​​the grounding ring 102 or only the upper half of the grounding ring 102. This application is not limited thereto.

[0044] In some embodiments, the shielding film 103 not only covers all or part of the grounding ring 102, but also covers the side portion of the detection electrode 101 not covered by the grounding ring 102. For example, the grounding ring 102 only covers the upper half of the side portion of the detection electrode 101, and the shielding film 103 not only covers the lower half of the grounding ring 102, but also covers the lower half of the side portion of the detection electrode 101 not covered by the grounding ring 102. This application is not limited to this.

[0045] In some embodiments, the shielding film 103 partially covers the top and / or bottom surfaces of the detection electrode 101. For example, the shielding film 103 only covers the outer portion of the top and / or bottom surfaces of the detection electrode 101, and its coverage area is 1 / 20 of the top and / or bottom surfaces of the detection electrode 101. This application is not limited to this.

[0046] In some embodiments, the grounding ring 102 can uniformly wrap around the detection electrode 101, or the grounding ring 102 can have the largest thickness at one end and the smallest thickness at the other end. The wrapping of the detection electrode 101 can be achieved by uniformly adjusting the thickness. This is not limited to this.

[0047] For example, the grounding ring 102 wraps around the side of the detection electrode 101, and the thickness of the grounding ring 102 is uniformly reduced from top to bottom to achieve the wrapping of the side of the detection electrode 101. The shielding film 103 uniformly wraps around the grounding ring 102. Based on this design, the capacitive proximity sensor can provide a stronger shielding effect at the top and allow a certain degree of electromagnetic interference at the bottom to better adapt to different electric field conditions.

[0048] In some embodiments, the shielding film 103 can uniformly wrap the grounding ring 102, or the shielding film 103 can have the largest thickness at one end of the grounding ring 102 and the smallest thickness at the other end. The wrapping of the grounding ring 102 can be achieved by uniformly adjusting the thickness. This is not limited to this.

[0049] For example, the grounding ring 102 uniformly wraps the side of the detection electrode 101, and the shielding film 103 wraps the grounding ring 102. The grounding ring 102 is wrapped by uniformly reducing the thickness of the shielding film 103 from top to bottom. Based on this design, the capacitive proximity sensor can have different shielding effects in different parts to better adapt to different electric field conditions.

[0050] In some embodiments, the detection electrode has a cylindrical structure with a ring-shaped side surface. The grounding ring and the shielding film are respectively disposed around the ring-shaped side surface; and the detection electrode, the grounding ring, and the shielding film are coaxial. Based on this coaxial structure, the detection electrode 101 can generate a uniform electric field distribution, effectively suppressing external electromagnetic interference and reducing the influence of surrounding metal on the detection electrode 101.

[0051] In some embodiments, the detection electrode 101 is a sphere or other shape, but this application is not limited thereto.

[0052] For example, when the detection electrode 101 is a sphere, and the grounding ring 102 and the shielding film 103 form a ring that uniformly wraps around the detection electrode 101, and the detection electrode 101, the grounding ring 102 and the shielding film 103 are coaxial, the detection electrode 101 can generate a uniform electric field distribution. The distribution of the electric field on and around the surface of the capacitive proximity sensor is relatively consistent, which can effectively suppress external electromagnetic interference and reduce the influence of surrounding metal on the detection electrode 101.

[0053] For example, when the detection electrode is a cuboid and the detection electrode 101, grounding ring 102 and shielding film 103 are coaxial, if the grounding ring 102 and shielding film 103 wrap around the side of the detection electrode 101 and have a higher thickness at the corners and edges of the detection electrode 101, the interference of the external electric field can be effectively reduced and the influence of the surrounding metal on the detection electrode 101 can be reduced.

[0054] In some embodiments, the detection electrode 101, the grounding ring 102, and the shielding film 103 may be non-axial or partially coaxial. For example, the detection electrode 101 and the grounding ring 102 may be coaxial, while the shielding film 103 may be non-axial with the detection electrode 101 and the grounding ring 102. This application is not limited to this.

[0055] In some embodiments, the detection electrode plate 104 has a cylindrical structure, and its outer diameter is larger than the outer diameters of the top and bottom surfaces of the detection electrode 101, such as... Figure 2As shown. Based on this, the detection electrode plate 104 and the grounding ring 102 have no direct contact and are naturally insulated from each other. When surrounding metal approaches the capacitive proximity sensor electrode 100, the insulating layer naturally formed between the grounding ring 102 and the detection electrode 101 limits the influence of the surrounding metal to a certain range, thereby stabilizing the electric field distribution and reducing the influence of the surrounding metal on the detection electrode 101. In some embodiments, the grounding ring 102 is a metal ring-shaped component surrounding the side of the detection electrode 101, which may be made of copper, but this application is not limited thereto.

[0056] In some embodiments, the shielding film 103 is a metal ring-shaped component surrounding the grounding ring 102, and an insulating layer is provided between the shielding film 103 and the grounding ring 102. The shielding film 103 is provided on the outside of the grounding ring 102, further improving the shielding performance against surrounding metal and reducing the influence of external electromagnetic interference. Furthermore, the shielding film 103 is a metal ring structure, which may be composed of copper; this application is not limited to this.

[0057] In some embodiments, the shielding film 103 is not connected to the excitation source or is not connected to ground, and the shielding film 103 has a floating potential. The shielding film 103 with a floating potential can effectively shield external electric fields and electromagnetic interference, reduce the impact of noise on the sensor, and improve the sensor's detection accuracy. Furthermore, the shielding film 103 with a floating potential can improve the electric field distribution of the detection electrode 101, reduce the influence of surrounding metal on the detection electrode 101, and ensure the accuracy of the detection results.

[0058] In some embodiments, the shielding film 103 forms a Faraday cage structure.

[0059] Figure 3 This is a schematic diagram of the surrounding metal near the electrodes of a capacitive proximity sensor according to an embodiment of this application, as shown. Figure 3 As shown, when the surrounding metal 106 approaches the detection electrode 101, the shielding film 103 is affected by the surrounding metal and generates induced charge, blocking the electric field generated by the surrounding metal 106. At this time, the shielding film 103 is an equipotential body, and its internal structure is not affected by the surrounding metal 106. That is, the detection electrode 101 is not affected by the surrounding metal 106, thereby achieving high shielding performance against the surrounding metal.

[0060] It is worth noting that the above description only provides an exemplary illustration of the configuration of the capacitive proximity sensor electrode and the capacitive proximity sensor related to this application. However, this application is not limited to this, and appropriate modifications can be made based on the above embodiments. Furthermore, the capacitive proximity sensor electrode and the capacitive proximity sensor may also include other configurations, which can be found in related technologies. Additionally, the above description only provides an exemplary illustration of each component, but this application is not limited to this. The specific content of each component can be found in related technologies; furthermore, components not shown in the figures can be added, or one or more components in the figures can be removed.

[0061] The present application has been described above with reference to specific embodiments. However, those skilled in the art should understand that these descriptions are exemplary and not intended to limit the scope of protection of the present application. Those skilled in the art can make various modifications and variations to the present application based on its spirit and principles, and these modifications and variations are also within the scope of the present application.

[0062] Although this disclosure and the disclosure which is currently considered to be its best mode have been described in a manner that identifies the inventor and enables those skilled in the art to make and use it, it should be understood and appreciated that many equivalents of the exemplary embodiments disclosed herein exist and that various modifications and variations may be made thereto without departing from the scope and spirit of this disclosure, which is not limited to the exemplary embodiments but rather to the appended claims.

Claims

1. A capacitive proximity sensor electrode, characterized in that, The capacitive proximity sensor electrodes include: A detection electrode includes a detection electrode plate forming the side surface of the detection electrode, and the top and bottom surfaces of the detection electrode are located within the detection electrode plate. A grounding ring, located outside the detection electrode, and the grounding ring wrapping around the side surface of the detection electrode; and A shielding film is located on the outside of the grounding ring and wraps around the grounding ring.

2. The capacitive proximity sensor electrode according to claim 1, characterized in that, The detection electrode has a cylindrical structure, and the grounding ring and the shielding film are respectively arranged around the side; and the detection electrode, the grounding ring and the shielding film are coaxial.

3. The capacitive proximity sensor electrode according to claim 2, characterized in that, The outer diameters of the top and bottom surfaces of the detection electrode are smaller than the outer diameter of the detection electrode plate.

4. The capacitive proximity sensor electrode according to claim 1, characterized in that, The grounding ring protrudes from the detection electrode.

5. The capacitive proximity sensor electrode according to claim 1, characterized in that, The grounding ring is a metal ring-shaped component that surrounds the side of the detection electrode.

6. The capacitive proximity sensor electrode according to claim 1, characterized in that, The shielding film is a metal ring-shaped component surrounding the grounding ring, and an insulating layer is provided between the shielding film and the grounding ring.

7. The capacitive proximity sensor electrode according to claim 1, characterized in that, The shielding film is not connected to the excitation source or is not connected to ground, and the shielding film has a floating potential.

8. The capacitive proximity sensor electrode according to claim 1, characterized in that, The shielding film forms a Faraday cage structure.

9. A capacitive proximity sensor, characterized in that, The sensor includes the capacitive proximity sensor electrode as described in any one of claims 1 to 8.

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