Capacitive sensing key structure

Abstract

The capacitive sensing key structure comprises a key base, a receiving plate, a transmitting plate, a pressing handle and a reset spring which are installed on a PCB, the receiving plate is relatively fixedly arranged in the key base, the transmitting plate is adjacent to the receiving plate and is relatively parallel to the receiving plate, and the transmitting plate and the pressing handle are in linkage and can move up and down relative to the key base; capacitance is formed between the transmitting plate and the receiving plate, the transmitting plate is moved by pressing the pressing handle, and then the capacitance is changed. According to the scheme, through the linkage design of the transmitting plate and the pressing handle and the arrangement structure that the transmitting plate and the receiving plate are oppositely adjacent, the transmitting plate and the receiving plate directly move relative to each other, and capacitance change is generated by pressing the pressing handle to move the transmitting plate; according to the scheme, the distance between boards is greatly reduced, the capacitance can be larger and more stable, the anti-interference performance can be effectively enhanced, and the technical effect of accurate capacitance induction is achieved; the capacitance key is stable in overall structure, high in sensitivity and suitable for industrial production and use.

Description

Technical Field

[0001] The present invention relates to the field of buttons, and in particular to a capacitive sensing button structure. Background Art

[0002] A capacitive touch button is a new type of key switch. Its principle is that the user presses the conductive medium to move and thus change the capacitance. Based on the change in capacitance, the distance moved by the conductive medium is calculated to form a corresponding switch signal output. For example, the previously disclosed Chinese patent publication number CN118098855A discloses a capacitive sensing button, device, movement distance detection method and storage medium. It proposes a capacitive button. The first plate, conductive medium and second plate provided in the button form a capacitor. In addition, when the shaft core reciprocates, the capacitance signal generated by the capacitor changes accordingly. Based on the change in the capacitance signal, the distance moved by the conductive medium can be calculated. Since the position of the conductive medium and the shaft core is relatively fixed, the distance moved by the conductive medium can be determined from the distance moved by the shaft core. On the basis of being able to accurately determine the distance moved by the shaft core, any trigger stroke can be set on the button, the trigger time can be adjusted, etc., to bring different tactile experiences to the user. In the industry, the aforementioned first and second plates are also referred to as transmitting plates and receiving plates, and the conductive medium is generally also referred to as a guide plate.

[0003] Because this key relies on a conductive medium to form capacitance with the transmitter and receiver boards, the structural design requires a movable conductive medium (a guide plate) between the transmitter and receiver boards, resulting in a large spacing between them. This makes it difficult to increase the capacitance between the transmitter and receiver boards, making it difficult to further improve signal stability and anti-interference capabilities. The solution of this application aims to provide innovative improvements to address the above shortcomings. Summary of the Invention

[0004] In view of the above problems, the present invention aims to provide a capacitive sensing key structure with strong anti-interference capability and large capacitance.

[0005] To achieve this technical objective, the present invention provides: a capacitive sensing key structure, comprising a key base mounted on a PCB board, a receiving plate and a transmitting plate, a push handle capable of moving up and down relative to the key base, and a reset spring for resetting the push handle; the receiving plate is relatively fixedly arranged in the key base, the transmitting plate is adjacent to the receiving plate and relatively parallel to the receiving plate, the transmitting plate and the push handle are linked and can move up and down relative to the key base; a capacitor is formed between the transmitting plate and the receiving plate, and pressing the push handle causes the transmitting plate to move, thereby causing the capacitor to change.

[0006] Preferably, the transmitting plate is electrically connected to the upper end of the reset spring, the lower end of the reset spring is electrically connected to the transmitting plate pin, and the transmitting plate is electrically connected to the PCB board through the reset spring and the transmitting plate pin; the receiving plate has a receiving plate pin extending from the key seat and is electrically connected to the PCB board.

[0007] Preferably, the key further comprises an independent balance block capable of moving up and down relative to the key base;

[0008] The top of the balance block abuts against the button handle, one end of the return spring abuts against the bottom of the balance block, and the other end of the return spring abuts against the launch plate pin, and the launch plate is fixedly mounted on the balance block; a hollow guide platform extends upward from the middle of the key seat, and the balance block is provided with a guide hole matching the hollow guide platform, and the balance block is sleeved on the hollow guide platform through the guide hole to guide the stable up and down movement of the balance block.

[0009] Preferably, the transmitting board pin member includes an abutting end and a pin end extending from the abutting end toward the bottom of the key seat, the abutting end abuts against the bottom of the reset spring to form an electrical connection, and the pin end is electrically connected to the PCB board.

[0010] Preferably, the abutting end is an annular structure, and the abutting end of the annular structure is sleeved on the outer periphery of the guide platform and abuts against the bottom of the reset spring.

[0011] Preferably, a guide column extends from the bottom of the push handle, and the guide column matches the hollow structure of the hollow guide platform. The guide column passes through the guide hole of the balance block and is inserted into the hollow guide platform to guide the stable up and down movement of the push handle.

[0012] Preferably, the launch plate is mounted on one side of the balance block, and a snap-on structure that cooperates with the balance block extends from the top and side of the launch plate. A conductive plate that abuts against the top of the reset spring extends from the top of the launch plate into the balance block.

[0013] Preferably, a receiving plate accommodating groove for fixing the receiving plate is provided in the key base, and a spring accommodating ring cavity for installing a reset spring is provided in the balancing block.

[0014] Preferably, the side of the balancing weight and the key seat are further provided with a guide structure.

[0015] Preferably, the guide structure includes a guide rail constructed on the side of the balance block and a guide groove constructed in the key seat corresponding to the guide rail.

[0016] The beneficial effects of the present invention are as follows: this solution realizes that the transmitting plate and the button handle are linked in design, and the transmitting plate and the receiving plate are arranged in a relatively adjacent layout structure, so that the transmitting plate and the receiving plate can move directly relative to each other, and the capacitance change is generated by pressing the button handle to move the transmitting plate; this solution greatly reduces the distance between the plates, can achieve a larger and more stable capacitance, can effectively enhance the anti-interference performance, and achieve the technical effect of precise capacitance sensing; this innovative capacitive button has a stable overall structure and high sensitivity, and is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 An exploded view of the present invention;

[0018] Figure 2 is a cross-sectional view of the present invention;

[0019] Figure 3 It is a structural diagram of the launch plate and the balance block in the present invention;

[0020] Figure 4 Schematic diagram of the structure of the launch plate and the return spring in the present invention;

[0021] Figure 5 Schematic diagram of the structure of the receiving plate in the present invention;

[0022] Figure 6 Schematic diagram of the structure of the key base in the present invention;

[0023] Figure 7 It is a structural schematic diagram of the balancing weight in the present invention.

[0024] In the figure: 1. PCB board; 2. key base; 21. hollow guide platform; 22. extended circular table; 23. receiving board accommodating groove; 24. guide groove; 3. receiving board; 31. receiving board pin; 4. transmitting board; 41. transmitting board pin member; 410. abutting end; 411. pin end; 42. conductive plate; 5. button handle; 51. guide column; 6. reset spring; 7. balance block; 71. guide hole; 72. snap-fit structure; 73. spring accommodating ring cavity; 74. guide rail; 75. boss; 8. conductive socket. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. In order to clearly and completely describe the technical solution, the following embodiments are selected for illustration; the following embodiments are part of the embodiments of the present invention; based on this application, other embodiments obtained without creative work are all within the scope of protection of the present invention.

[0026] In the following embodiments, it should be noted that the terms "upper," "lower," "left," "right," "inner," "outer," "top / bottom," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the clear description of the embodiments. They do not indicate or imply that the devices or components referred to must have a specific orientation and should not be construed as limitations on the present application. Furthermore, the terms "first" and "second" in the embodiments are used solely for descriptive purposes and do not indicate or imply relative importance.

[0027] like Figure 1-7 As shown, the specific embodiment described in the present invention is a capacitive sensing key structure, including a key base 2 installed on a PCB board 1, a receiving board 3 and a transmitting board 4, a button handle 5 that can move up and down relative to the key base 2, and a reset spring 6 for resetting the button handle 5.

[0028] The receiving plate 3 is securely mounted within the keybed 2, while the transmitting plate 4 is adjacent to and parallel to the receiving plate 3. The two are closely adjacent, but with a slight gap between them, thereby forming a capacitor between the transmitting plate 4 and the receiving plate 3. By moving the transmitting plate 4 to produce a capacitance change, the transmitting plate 4 and the receiving plate 3 move directly relative to each other. Pressing the handle 5 to move the transmitting plate 4 to produce a capacitance change reduces the relative distance between the transmitting plate 4 and the receiving plate 3. This not only increases and stabilizes the capacitance, but also, compared to the prior art method of changing capacitance through a conductive medium (guide plate), the direct movement of the transmitting plate in this solution to change capacitance more effectively enhances anti-interference performance, thereby achieving precise capacitive sensing.

[0029] When the handle 5 is pressed, the transmitter plate 4 moves, causing the relative distance and area between it and the receiver plate 3 to change, which in turn causes a change in capacitance. Because the transmitter plate 4 and the handle 5 are linked, they can quickly respond to the pressing action of the handle 5, ensuring that the capacitance change is detected promptly and accurately, effectively improving the sensitivity of the key.

[0030] Specifically, the receiving plate 3 is provided with a plurality of trapezoidal areas (such as Figure 5 (As shown in Figure 1, Rx1, Rx2, Rx3, Rx4, and Rx5). During the downward pressure process, the capacitance of regions Rx2 and Rx4 increases, while the capacitance of regions Rx1, Rx3, and Rx5 decreases, resulting in a capacitance change. By detecting the capacitance change between the transmitting plate 4 and each region, the travel distance of the transmitting plate 4 can be calculated.

[0031] In this embodiment, the return spring 6 is made of a conductive material or coated with a conductive layer on its surface to achieve good electrical conductivity. The return spring 6 in this embodiment not only performs a reset function but also serves as an electrical connection component, ensuring the reliability of the electrical connection between the transmitting board 4 and the subsequent circuit. Specifically, the upper end of the return spring 6 is electrically connected to the transmitting board 4, and the lower end of the return spring 6 is electrically connected to the transmitting board pin 41. The transmitting board pin 41 is electrically connected to the PCB board 1. The transmitting board 4 establishes a stable electrical connection with the PCB board 1 through the path formed by the return spring 6 and the transmitting board pin 41, thereby ensuring that the capacitance change signal generated by the transmitting board 4 can be smoothly transmitted to the PCB board 1 via the transmitting board pin 41 and electrically connected to the conductive socket 8 on the PCB board 1. Similarly, the receiving board 3 is also designed with receiving board pins 31 extending from the key base 2. The receiving board 3 is electrically connected to the PCB board 1 via these receiving board pins 31, and then the capacitance change signal detected by the receiving board 3 is transmitted to the PCB board 1, and electrically connected to the conductive socket 8 on the PCB board 1.

[0032] In this key scheme, the linkage between the launch plate 4 and the push handle 5 is achieved by an independent counterweight 7. Specifically, the key structure includes an independent counterweight 7 that can move up and down relative to the keybed 2. The top of the counterweight 7 is provided with a boss 75 that abuts the push handle 5. One end of the return spring 6 abuts both the counterweight 7 and the bottom of the launch plate 4, while the other end abuts the launch plate pin 41. The launch plate 4 is fixedly mounted on the counterweight 7.

[0033] A hollow guide platform 21 extends upward from the middle of the keybed 2, and a matching guide hole 71 is provided on the balance block 7. The balance block 7 is mounted on the hollow guide platform 21 through the guide hole 71 to achieve stable guidance for up and down movement. When the user presses the button 5, the pressure exerted on the button 5 is transmitted to the balance block 7. Under the action of pressure, the balance block 7 moves downward along the hollow guide platform 21 of the keybed 2. Since the transmitting plate 4 is fixed on the balance block 7, it will move downward synchronously with the balance block 7. The transmitting plate 4 and the receiving plate 3 were originally close to each other with a certain gap. After the transmitting plate 4 moves downward, the relative distance and relative area between the two change, which leads to a change in capacitance.

[0034] The hollow guide platform 21 has an extended circular platform 22 at its base, around which the coil of the return spring 6 is sheathed. The launcher pin 41 includes an abutment end 410 and a pin end 411. The pin end 411 extends downward from the abutment end 410 to below the keybed 2. The abutment end 410, designed as a ring, also sheaths around the extended circular platform 22 and forms close contact with the bottom of the return spring 6, forming a stable support structure and ensuring a reliable electrical connection.

[0035] A guide post 51 extends downward from the bottom of the handle 5. This post 51 fits within the hollow structure of the hollow guide platform 21 and can pass through a pre-set guide hole 71 in the balance block 7 and precisely insert into the hollow guide platform 21. This design provides precise guidance for the up and down movement of the handle 5, effectively preventing it from shifting or shaking during movement and ensuring stable key operation.

[0036] In this key structure, the launch plate 4 is positioned to one side of the counterweight 7. Extending from the top and sides of the launch plate 4 are snap-fit structures 72 that mate with the counterweight 7. This design ensures a stable connection between the launch plate 4 and the counterweight 7 during the pressing and releasing of the button handle 5. The snap-fit structure 72 can take a variety of forms, such as elastic hooks, bosses 75, and grooves, among other common snap-fit structures. Furthermore, a conductive plate 42 extends from the top of the launch plate 4 into the counterweight 7, abutting the top of the return spring 6. To ensure good electrical conductivity, this conductive plate 42 is preferably made of sheet metal.

[0037] The keybed 2 is internally designed with a receiving plate accommodating groove 23, providing a stable and precise mounting space for the receiving plate 3, ensuring that the transmitting plate 4 can be securely placed therein. Simultaneously, a spring accommodating annular cavity 73 is also provided within the balancing weight 7, providing a stable mounting space for the return spring 6, ensuring its reliable fixation.

[0038] To ensure stable up and down movement of the balancing weight 7, guide structures are provided on its sides and on the keybed 2. This structure primarily serves a guiding and positioning function. During relative motion between the balancing weight 7 and the keybed 2, the guide structure precisely guides both along a predetermined trajectory, effectively preventing potential deviation during movement and thus ensuring smooth and stable operation of the entire device. Specifically, the guide structure of the balancing weight 7 utilizes side guide rails 74, while the guide structure of the keybed 2 matches this design with guide grooves 24. These two structures work together to ensure stable operation of the device.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any minor modifications, equivalent replacements, and improvements made to the above embodiments based on the technical essence of the present invention shall be included in the scope of protection of the technical solution of the present invention.

Claims

1. A capacitive sensing key structure, comprising a key base mounted on a PCB, a receiving board and a transmitting board, a handle capable of moving up and down relative to the key base, and a return spring for returning the handle to its original position, characterized in that: The receiving plate is relatively fixedly arranged in the key base, the transmitting plate is adjacent to the receiving plate and relatively parallel to the receiving plate, and the transmitting plate is linked with the handle and can move up and down relative to the key base; a capacitor is formed between the transmitting plate and the receiving plate, and pressing the handle moves the transmitting plate, thereby causing the capacitor to change.

2. The capacitive sensing button structure according to claim 1, characterized in that: The transmitting plate is electrically connected to the upper end of the reset spring, the lower end of the reset spring is electrically connected to the transmitting plate pin, and the transmitting plate is electrically connected to the PCB board through the reset spring and the transmitting plate pin; the receiving plate has a receiving plate pin extending from the key seat and is electrically connected to the PCB board.

3. The capacitive sensing button structure according to claim 2, wherein: The key also includes an independent balance block that can move up and down relative to the key base; The top of the balance block abuts against the button handle, one end of the return spring abuts against the bottom of the balance block, and the other end of the return spring abuts against the launch plate pin, and the launch plate is fixedly mounted on the balance block; a hollow guide platform extends upward from the middle of the key seat, and the balance block is provided with a guide hole matching the hollow guide platform, and the balance block is sleeved on the hollow guide platform through the guide hole to guide the stable up and down movement of the balance block.

4. The capacitive sensing button structure according to claim 3, characterized in that: The transmitting board pin includes an abutting end and a pin end extending from the abutting end toward the bottom of the key base, the abutting end abuts against the bottom of the reset spring to form an electrical connection, and the pin end is electrically connected to the PCB board.

5. The capacitive sensing button structure according to claim 4, characterized in that: The abutting end is an annular structure, and the abutting end of the annular structure is sleeved on the outer periphery of the guide platform and abuts against the bottom of the reset spring.

6. The capacitive sensing button structure according to claim 5, characterized in that: A guide column extends from the bottom of the handle, and the guide column matches the hollow structure of the hollow guide platform. The guide column passes through the guide hole of the balance block and is inserted into the hollow guide platform to guide the stable up and down movement of the handle.

7. The capacitive sensing button structure according to claim 3, wherein: The launch plate is installed on one side of the balance block, and the top and side of the launch plate extend with a snap structure that cooperates with the balance block. The top of the launch plate also extends into the balance block to form a conductive plate that abuts against the top of the reset spring.

8. The capacitive sensing button structure according to claim 3, wherein: A receiving plate accommodating groove for fixing the receiving plate is provided in the key base, and a spring accommodating ring cavity for installing a reset spring is provided in the balance block.

9. The capacitive sensing button structure according to claim 3, wherein: The side of the balance block and the key seat are also provided with a guide structure.

10. The capacitive sensing button structure according to claim 9, characterized in that: The guide structure includes a guide rail constructed on the side of the balance block and a guide groove constructed in the key seat corresponding to the guide rail.

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