Capacitive sensor and electronic device

Abstract

The embodiment of the utility model relates to the technical field of sensors, and discloses a capacitive sensor and electronic equipment. The capacitance sensor comprises a capacitance structure and a rotatable conductive piece. The capacitor structure comprises a first electrode and a plurality of second electrodes which are arranged on the same plane, and the first electrode and each second electrode are arranged at intervals. The conductive part and the capacitor structure are located on different planes, the conductive part comprises a first part opposite to the first electrode and a second part connected with the first part, and the second part can change the relative area with different second electrodes during rotation so as to change the capacitance formed by the second electrodes and the first electrode. According to the capacitive sensor and the electronic equipment provided by the embodiment of the invention, the detection precision of the sensor can be ensured.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of sensor technology, and in particular to a capacitive sensor and electronic equipment. Background Art

[0002] With the continuous development of electronic technology, a variety of electronic devices capable of performing different functions have begun to appear in users' fields of vision. The use of these electronic devices is inseparable from the configuration of numerous sensors. Sensors can detect corresponding physical parameters, thereby understanding the operating environment of electronic devices, monitoring the operation of electronic devices, or providing feedback on detection information.

[0003] Sensors convert the detected object into a relevant physical quantity, and then reflect changes in the detected object based on changes in the physical quantity. However, various constraints can affect sensor accuracy during sensor configuration. Therefore, ensuring accurate sensor design is crucial for achieving relevant detection projects. Utility Model Content

[0004] The purpose of the embodiments of the present application is to provide a capacitive sensor and an electronic device, which can help ensure the detection accuracy of the sensor.

[0005] To solve the above technical problems, an embodiment of the present application provides a capacitive sensor. The capacitive sensor includes a capacitive structure and a rotatable conductive member. The capacitive structure includes a first electrode and a plurality of second electrodes arranged on the same plane, and the first electrode and each second electrode are spaced apart from each other. The conductive member and the capacitive structure are located on different planes, and the conductive member includes a first part opposite to the first electrode, and a second part connected to the first part. The second part can change the relative area with different second electrodes when rotating to change the size of the capacitance formed by the second electrode and the first electrode.

[0006] Embodiments of the present application also provide an electronic device. The electronic device includes a base and a rotating member rotatably disposed on the base. The electronic device also includes the aforementioned capacitive sensor, wherein the capacitive structure of the capacitive sensor is disposed on the base, and the conductive member of the capacitive sensor is disposed on the rotating member.

[0007] The capacitive sensor and electronic device provided by the embodiments of the present application use different electrodes to form a capacitive structure, and the capacitive structure can cooperate with a conductive member. As the conductive member rotates with the rotating component, the relative area with the electrode changes, thereby causing the size of the capacitance formed between different electrodes to change. The detection of rotation parameter information can be achieved based on the change in capacitance. In addition, by using a conductive member, the influence of electrical connection lines during the detection process can be avoided, which is conducive to ensuring the detection accuracy of the sensor.

[0008] In some embodiments, multiple second electrodes are arranged in groups, with the second electrodes in the same group having a first spacing, and adjacent second electrodes in two adjacent groups having a second spacing greater than the first spacing. This allows for the generation of multiple capacitance signals through grouping to offset the impact of actual distance assembly errors on detection results.

[0009] In some embodiments, the second electrodes in the same group include a first sub-electrode and a second sub-electrode arranged sequentially. First sub-electrodes in different groups are electrically connected to each other, and second sub-electrodes in different groups are electrically connected to each other. This allows for the equivalent amplification of the detected capacitance signal by connecting multiple sub-electrodes, thereby improving detection accuracy.

[0010] In some embodiments, the two second electrodes in the same group have the same projected shape on the same plane. This allows the use of electrodes of the same shape and size to ensure that the capacitance variation range formed by different second electrodes and the first electrode is relatively consistent, reducing the difficulty of data processing.

[0011] In some embodiments, the conductive member has multiple stop positions in the rotation direction, and when the conductive member is in the stop position, the second portion is opposite to the area corresponding to the second interval. In this way, the detection signal can be initialized by making the second portion opposite to the second interval when in the stop state.

[0012] In some embodiments, the first portion is configured in a ring shape, and the projection of the first portion onto the plane where the first electrode is located covers the edge of the first electrode. In this way, by having the first portion cover the first electrode, the capacitance formed by the first electrode and the second electrode can be ensured.

[0013] In some embodiments, there are multiple second parts, and the multiple second parts are evenly distributed around the periphery of the first part. In this way, multiple capacitance signals can be generated simultaneously through the multiple second parts, which facilitates amplification of the detection signal and improves detection accuracy.

[0014] In some embodiments, the capacitor structure includes a ground electrode located between the first electrode and the plurality of second electrodes. In this way, the ground electrode can reduce the influence of unnecessary capacitance signals and improve detection sensitivity.

[0015] In some embodiments, the capacitive sensor further includes a circuit board, the capacitive structure is disposed on a surface of the circuit board, and the first electrode and the plurality of second electrodes are formed by copper-plated areas on the circuit board surface. In this way, the capacitive structure can be arranged on the circuit board, facilitating the configuration of the capacitive sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0017] Figure 1 is a schematic structural diagram of a capacitive sensor provided in some embodiments of the present application;

[0018] Figure 2 is a schematic diagram of a partially enlarged structure of a capacitive sensor provided in some embodiments of the present application;

[0019] Figure 3 is a schematic diagram showing how the capacitance of a capacitive sensor varies with angle, provided in some embodiments of the present application;

[0020] Figure 4 is a schematic structural diagram of a conductive member in a capacitive sensor provided in some embodiments of the present application;

[0021] Figure 5 is a schematic structural diagram of a capacitive structure in a capacitive sensor provided in some embodiments of the present application when it is disposed on a circuit board;

[0022] Figure 6 is a schematic diagram of the structure of the capacitive sensor provided in some embodiments of the present application when in use;

[0023] Figure 7 This is a schematic diagram of the assembly structure of the conductive parts in the capacitive sensor provided in some embodiments of the present application. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, each embodiment of the present application will be described in detail below with reference to the accompanying drawings. However, it will be understood by those skilled in the art that in each embodiment of the present application, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present application can be implemented. The division of the following embodiments is for convenience of description and should not constitute any limitation on the specific implementation of the present application. The various embodiments can be combined with each other and referenced to each other under the premise of no contradiction.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0026] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections, or electrical connections; direct connections, or indirect connections through an intermediate medium; and can refer to internal connectivity between two components or interaction between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0027] With the continuous emergence of various sensors, electronic devices can be equipped with more sensors to achieve more functions. In electronic devices, the detection of rotation parameters is an important detection item. By detecting the rotation of the rotating parts, information such as the rotation angle, rotation speed or rotation acceleration can be obtained in a timely manner, so as to monitor the rotation parameters or accurately control the rotation motion. Rotation detection can be applied to various encoders, angle sensors, speed sensors and other sensors involving the detection of physical quantities such as angle, angular velocity, angular acceleration, etc. This type of sensor can be used in rotating parts such as mouse wheels, and can also be used in high-tech fields such as drones, consoles, high-end medical care, chip design and manufacturing, aerospace, etc.

[0028] Currently, sensors used for motion detection primarily include contact and non-contact types. Contact encoders typically consist of a code disk and brushes. Due to friction during the detection process, they have a short lifespan. Furthermore, due to contact limitations, they are not suitable for high-speed applications. Non-contact sensors, on the other hand, utilize a non-contact detection method and are unaffected by the medium in space. For example, photoelectric encoders can detect motion by detecting the on / off state of light signals, while magnetic encoders can detect motion by detecting changes in magnetic fields. However, photoelectric encoders are relatively expensive and have a detection backlash, while magnetic encoders are susceptible to environmental influences.

[0029] To ensure sensor detection accuracy, some embodiments of the present application provide a capacitive sensor for detecting rotational parameters. This sensor detects the rotation of rotating components, such as knobs, by arranging capacitive plates and cooperating with a floating conductive medium. This sensor is not only cost-effective but also offers high detection accuracy, no dead zone detection, and strong anti-interference capabilities.

[0030] The structures of the capacitive sensors provided by some embodiments of the present application are described below with reference to the accompanying drawings.

[0031] like Figure 1 and Figure 2As shown, the capacitive sensor provided by some embodiments of the present application includes a capacitive structure 11 and a rotatable conductive member 12. The capacitive structure 11 includes a first electrode 111 and a plurality of second electrodes 112 arranged on the same plane, and the first electrode 111 and each second electrode 112 are spaced apart from each other. The conductive member 12 and the capacitive structure 11 are located on different planes. The conductive member 12 includes a first portion 121 opposite to the first electrode 111, and a second portion 122 connected to the first portion 121. The second portion 122 can change the relative area with different second electrodes 112 when rotating, thereby changing the size of the capacitance formed by the second electrode 112 and the first electrode 111.

[0032] The first electrode 111 and the second electrode 112 are electrode plates located at different positions in the capacitor structure 11. One of the first electrode 111 and the second electrode 112 is a transmitting electrode, and the other is a receiving electrode. The transmitting electrode is located at the excitation signal end, and the receiving electrode is located at the detection signal end. Figure 1 and Figure 2 In the figure, the first electrode 111 is used as the transmitting electrode and the second electrode 112 is used as the receiving electrode. A capacitor structure 11 can be formed by the cooperation between the first electrode 111 and the second electrode 112. At the same time, the first electrode 111 and the second electrode 112 are located on the same plane, and a capacitor can be formed under the relative action of the conductive member 12. Multiple second electrodes 112 can form multiple capacitance signals during the detection process, thereby improving the accuracy of the detection process. The capacitance signals during the detection process can be collected and processed by the processor to obtain the rotation parameter information of the rotating component.

[0033] The conductive member 12 and the capacitor structure 11 are located on different planes and have a certain interval. Different parts of the conductive member 12 can form a relative relationship with the first electrode 111 and the second electrode 112, so as to electrically connect the first electrode 111 and the second electrode 112 in the air. On the basis of the capacitor directly formed by the first electrode 111 and the second electrode 112, the first part 121 of the conductive member 12 forms a capacitor relative to the first electrode 111, and the second part 122 of the conductive member 12 forms a capacitor relative to the different second electrodes 112 when rotating. At the same time, the first part 121 and the second part 122 of the conductive member 12 are connected as a whole, which can be integrally formed or split and connected together, and then in the process of cooperating with the first electrode 111 and the second electrode 112, it can be equivalent to two capacitors connected in series. That is, under the action of the conductive member 12, a capacitor of a specific size can be formed between the first electrode 111 and the second electrode 112. Moreover, during the rotation of the conductive member 12, the relative area between the second portion 122 of the conductive member 12 and the second electrode 112 changes, and then, since the capacitance is linearly related to the facing area, the capacitance formed by the first electrode 111 and the second electrode 112 will also change accordingly. Thus, the rotation of the rotating component can be detected by detecting the change in capacitance. For example, the rotation direction and rotation angle of the rotating component can be detected by detecting the change in capacitance signal. By detecting the rotation angle, rotation parameters such as rotation speed and rotation acceleration can be further calculated. In actual situations, the conductive member 12 can be a metal sheet or a metal plate.

[0034] By setting the first electrode 111 and the second electrode 112 at fixed positions on the same plane, it is possible to avoid directly detecting the movement of the first electrode 111 or the second electrode 112, which would require electrical connection lines to be arranged on the moving parts. The detection process can avoid being affected by the electrical connection lines, thereby avoiding affecting the accuracy and range of the detection. The conductive member 12 can follow the movement of the rotating part that needs to be rotated in the electronic device, and then convert the change in the rotation parameter of the rotating part into a change in the capacitance signal. At the same time, this arrangement can reduce the space occupied, and the first electrode 111 and the second electrode 112 that need to be electrically connected can be arranged in a smaller range, while the conductive member 12 that does not need to be electrically connected can be arranged together with the rotating part in a larger range.

[0035] The capacitive sensor provided in some embodiments of the present application uses different electrodes to form a capacitive structure 11, and the capacitive structure 11 can cooperate with a conductive member 12. In the process of following the rotation of the rotating component, the conductive member 12 changes the relative area with the electrode, thereby causing the size of the capacitance formed between different electrodes to change. The detection of rotation parameter information can be achieved based on the change in capacitance. In addition, by using the conductive member 12, the influence of the electrical connection line during the detection process can be avoided, which is conducive to ensuring the detection accuracy of the sensor.

[0036] like Figure 1 and Figure 2 As shown, the plurality of second electrodes 112 can be arranged in groups, and the second electrodes 112 in the same group have a first interval 101. There is a second interval 102 between two adjacent second electrodes 112 in two adjacent groups, and the second interval 102 is larger than the first interval 101.

[0037] That is to say, a plurality of second electrodes 112 can be arranged in groups, and the second electrodes 112 and the first electrodes 111 in the same group can form a group of capacitance signals with different changes. In the process of the conductive member 12 following the rotation of the rotating component, the change in the size of the capacitance formed by the different second electrodes 112 and the first electrode 111 can be used to detect the change in the rotation angle and the direction of rotation. For example, when the relative area between the second part 122 and one of the second electrodes 112 is constantly decreasing, and the relative area with the other second electrode 112 is constantly increasing, it can be determined that the direction of rotation of the conductive member 12 is toward the position of the second electrode 112 where the capacitance is constantly increasing. Combined with the processing of multiple groups of capacitance signals, the influence of the distance parameter on the detection result can be eliminated, thereby offsetting the influence of the distance assembly error on the detection result.

[0038] Moreover, according to the calculation formula of capacitance, there is a linear relationship between the change in capacitance and the change in relative area. Therefore, the change in rotation angle can be detected by the change in capacitance. Combined with the detection time, rotation parameter information such as rotation speed and rotation acceleration can be calculated. In actual circumstances, the second portion 122 and the different second electrodes 112 can be periodically arranged around the rotation center of the conductive member 12. For example, the area can be divided into three equal parts, that is, the second portion 122 and the two second electrodes 112 are periodically arranged with the same shape and size.

[0039] In addition, the second electrodes 112 in the same group may include first sub-electrodes 103 and second sub-electrodes 104 arranged in sequence, the first sub-electrodes 103 in different groups are electrically connected to each other, and the second sub-electrodes 104 in different groups are electrically connected to each other.

[0040] That is, corresponding second electrodes 112 in different groups can be electrically connected to each other. Thus, when multiple first sub-electrodes 103 or multiple second sub-electrodes 104 simultaneously generate capacitance signals, a single capacitance signal with a larger value can be generated, thereby increasing the amount of detected capacitance signals and improving detection accuracy.

[0041] Figure 3 The figure shows the finite element simulation data of the capacitance signal change in two cycles of the scheme, where the unit of angle is degree and the unit of capacitance is femtofarad. Assume that the capacitance between the first electrode 111 and the first sub-electrode 103 is C1, and the capacitance between the first electrode 111 and the second sub-electrode 104 is C2. Figure 3 As can be seen, as conductive member 12 begins to rotate from its initial position, C1 first increases, then decreases, and then increases again; while C2 first decreases, then increases, and then decreases again. There is a significant phase difference between the two. If conductive member 12 rotates in the opposite direction, the signal pattern is reversed. By analyzing and processing the capacitance signal, the rotation direction and angle of the rotating component can be determined.

[0042] In some embodiments, the projection shapes of two second electrodes 112 in the same group on the same plane are the same.

[0043] That is, the second electrodes 112 can be of the same shape. During the variation of the capacitance signal, the capacitances formed by the different second electrodes 112 and the first electrodes 111 are relatively consistent in the variation range and variation stroke, which is beneficial for the calculation and processing of the final detection result.

[0044] In actual situations, for reasons such as avoidance, the second electrode 112 may be made to be different in size and shape, and the detection of the rotation parameter information can still be achieved without affecting the final detection effect.

[0045] In some embodiments, the conductive member 12 may have a plurality of stop positions in the rotation direction. When the conductive member 12 is at the stop position, the second portion 122 is opposite to the area corresponding to the second interval 102 .

[0046] The conductive member 12 can be in a stopped state at the stop position. At this time, the second part 122 is opposite to the area corresponding to the second interval 102, and does not form a relative relationship with the second electrode 112. The capacitance formed by the second electrode 112 and the first electrode 111 is at a low point, which can be regarded as zeroing the detection stroke and initializing the detection process. For the rotation detection of some rotating parts with rotation gears, it can be helpful to judge whether the rotating parts are correctly returned to their positions. For example, in actual situations, the conductive member 12 can be installed on the knob and rotate with the knob. There are many wavy grooves and protrusions inside the knob housing, and the ball is embedded in the groove. When the knob rotates, the ball rolls between the grooves and protrusions to form gears, that is, the stop position, that is, the position where the knob can remain in the stopped state. At this time, it can be judged by the capacitance signal whether the knob housing has returned to the gear position.

[0047] like Figure 4 As shown, the first portion 121 may be provided in a ring shape, and the projection of the first portion 121 toward the plane where the first electrode 111 is located may cover the edge of the first electrode 111 .

[0048] The first portion 121 of the conductive member 12 has a complete annular structure, while the first electrode 111 is in the shape of an arcuate strip. During the rotation of the conductive member 12, the first portion 121 and the first electrode 111 are always in a relative position. Furthermore, the first portion 121 substantially covers the first electrode 111, ensuring the capacitance formed between the two. In practical situations, the first electrode 111 can also be annular, while the first portion 121 is in the shape of an arcuate strip.

[0049] In some embodiments, there may be a plurality of second portions 122 , and the plurality of second portions 122 are evenly distributed around the periphery of the first portion 121 .

[0050] Multiple second portions 122 can simultaneously interact with different second electrodes 112, thereby generating multiple sets of capacitance signals. The combined processing of multiple sets of capacitance signals helps improve detection accuracy and enhance the robustness of the sensor. The second portion 122 can be located inside or outside the first portion 121, forming a gear ring structure that can interact with opposing electrodes.

[0051] In addition, the capacitor structure 11 may include a ground electrode 113 , which is located between the first electrode 111 and the plurality of second electrodes 112 .

[0052] Grounding the ground electrode 113 can improve the detection sensitivity of the capacitive sensor. After the ground electrode 113 is arranged, the direct capacitance between the first electrode 111 and the second electrode 112 becomes smaller, thereby reducing the basic capacitance. Furthermore, during the rotation of the conductive member 12, the capacitance amplification factor formed by the first electrode 111 and the second electrode 112 becomes larger, which can improve the sensitivity of the final detection result. In actual situations, the ground electrode 113 can also be omitted without affecting the capacitive sensor's ability to achieve its detection purpose.

[0053] In some embodiments, as Figure 5 As shown, the capacitive sensor may further include a circuit board 13 , the capacitive structure 11 is disposed on a surface of the circuit board 13 , and the first electrode 111 and the plurality of second electrodes 112 are formed by a copper-plated area on the surface of the circuit board 13 .

[0054] The circuit board 13 can facilitate the arrangement of the capacitor structure 11, and the circuit board 13 can be provided with a processor to process the detected capacitance signal to obtain the final detection result. Different electrodes can be formed for different copper-plated areas on the surface of the circuit board 13, simplifying the formation of different electrodes. Moreover, it can effectively reduce the space occupied. In addition, a mounting hole 131 can be provided on the circuit board 13 to facilitate the installation and fixation of the circuit board 13.

[0055] Some embodiments of the present application also provide an electronic device, such as Figure 6 and Figure 7 As shown, the electronic device includes a base 21 and a rotating member 22 rotatably disposed on the base 21. The electronic device also includes the above-mentioned capacitive sensor, wherein the capacitive structure 11 of the capacitive sensor is disposed on the base 21 and the conductive member 12 of the capacitive sensor is disposed on the rotating member 22.

[0056] like Figure 6 and Figure 7 As shown, the rotating member is a knob, and the floating conductive member 12 is fixed to the knob. The capacitor structure can be arranged on a circuit board 13, which is fixed to a base 21 and has different electrode patterns designed on it. The knob is connected to the base 21 via a connector 23, and a rolling member 24 can be provided on the connector 23 to enable the knob to rotate with gears. The electronic device can be a camera device with knob control or a handheld terminal device that requires rotation detection.

[0057] In practice, when the knob is rotated clockwise or counterclockwise, the conductive member 12 also rotates. The area of contact between the second portion 122 of the conductive member 12 and the second electrode 112 changes periodically. The capacitance formed by the first electrode 111 and the second electrode 112 also changes periodically. By detecting changes in the capacitance signal, the direction and angle of rotation of the knob can be detected. By detecting the rotation angle, motion state information such as rotational speed and acceleration can be further calculated.

[0058] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present application, and that in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present application.

Claims

1. A capacitive sensor, characterized in that: include: A capacitor structure comprising a first electrode and a plurality of second electrodes arranged on the same plane, wherein the first electrode and each of the second electrodes are spaced apart from each other; A rotatable conductive member, wherein the conductive member and the capacitor structure are located on different planes, the conductive member includes a first portion opposite to the first electrode, and a second portion connected to the first portion, wherein the second portion can change the relative area with different second electrodes when rotating to change the size of the capacitance formed by the second electrode and the first electrode.

2. The capacitive sensor according to claim 1, wherein: A plurality of second electrodes are arranged in groups. The second electrodes in the same group have a first interval. Two second electrodes close to each other in two adjacent groups have a second interval, and the second interval is greater than the first interval.

3. The capacitive sensor according to claim 2, wherein: The second electrodes in the same group include first sub-electrodes and second sub-electrodes arranged in sequence. The first sub-electrodes in different groups are electrically connected to each other, and the second sub-electrodes in different groups are electrically connected to each other.

4. The capacitive sensor according to claim 2, wherein: The projection shapes of the two second electrodes in the same group on the same plane are the same.

5. The capacitive sensor according to claim 2, wherein: The conductive member has a plurality of stop positions in the rotation direction. When the conductive member is located at the stop positions, the second portion is opposite to an area corresponding to the second interval.

6. The capacitive sensor according to claim 1, wherein: The first portion is arranged in a ring shape, and a projection of the first portion toward the plane where the first electrode is located covers an edge of the first electrode.

7. The capacitive sensor according to claim 1, wherein: There are multiple second parts, and the multiple second parts are evenly distributed around the periphery of the first part.

8. The capacitive sensor according to claim 1, wherein: The capacitor structure includes a ground electrode located between the first electrode and the plurality of second electrodes.

9. The capacitive sensor according to claim 1, wherein: It also includes a circuit board, the capacitor structure is arranged on the surface of the circuit board, and the first electrode and the plurality of second electrodes are formed by a copper-plated area on the surface of the circuit board.

10. An electronic device comprising a base and a rotating member rotatably arranged on the base, characterized in that: It also includes the capacitive sensor according to any one of claims 1 to 9, wherein the capacitive structure of the capacitive sensor is arranged on the base, and the conductive part of the capacitive sensor is arranged on the rotating part.

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