Capacitor and entity composite key and identification method
By using a composite button structure combining capacitance and physical buttons, and combining capacitance value and voltage level judgment, the problem of accidental touches by physical buttons is solved, achieving high reliability and a rich human-computer interaction experience, while reducing hardware costs.
Patent Information
- Application Number
- CN202511241862.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-02
- Publication Date
- 2025-12-19
AI Technical Summary
Existing physical buttons are prone to accidental triggering due to external pressure or friction, affecting the ease of use of the device.
It adopts a composite button structure of capacitor and physical button, and distinguishes between human operation and external accidental touch by switching modes through the capacitance detection pin of the main control chip, combined with capacitance value change and level status judgment, and adds touch pre-detection function.
It effectively prevents accidental triggering, improves the reliability of button operation, enriches the human-computer interaction experience, reduces hardware costs, and allows users to flexibly configure anti-accidental touch and light touch functions.
Smart Images
Figure CN121173281A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of human-computer interaction of electronic equipment, and in particular to a capacitive and physical composite key and a recognition method. BACKGROUND
[0002] Mobile devices, such as smart phones, tablet computers, etc., are generally provided with physical mechanical keys, such as power keys, volume keys, etc. The most common physical key is currently a pot piece structure. Please refer to Fig. 1, which is a PCB circuit schematic diagram of a conventional pot piece key in the prior art, the structure comprising: a PCB board, on which a ring-shaped ground circuit and a circular center circuit are arranged in isolation; the circular center circuit is connected to a general-purpose input / output (GPIO) pin of a master control chip, for detecting a level signal; a metal pot piece is overlaid on the circuit, which is in contact with the ring-shaped ground circuit in normal state. Figure 1
[0003] When a user presses the key, the pot piece deforms, so that it simultaneously contacts the ring-shaped ground circuit and the circular center circuit, thereby pulling down the level of the circular center circuit to a ground (GND) level through the pot piece and the ring-shaped ground circuit 2, and when the master control chip detects that the GPIO pin becomes low level, it is determined that a key pressing operation has occurred.
[0004] However, the key of this structure has obvious defects: it only relies on the level change generated by mechanical contact for judgment, and can be triggered as long as sufficient physical pressure is applied. Therefore, when the device is placed in a small space such as a pocket, backpack, etc., and is squeezed or rubbed by external objects, it is easy to be triggered accidentally, causing the device to light up unexpectedly, adjust the volume or shut down, which brings trouble and inconvenience to the user.SUMMARY
[0005] The technical problem to be solved by the present application is to provide a capacitive and physical composite key and a recognition method, which effectively distinguishes between intentional human operation and external accidental touch without significantly increasing hardware cost and circuit complexity, and simultaneously adds a touch pre-detection function, enriching the human-computer interaction dimension.
[0006] To solve the above technical problems, the present application provides a capacitive and physical composite key, comprising a printed circuit board and a metal pot piece, the printed circuit board being provided with an outer ring circuit and an inner ring circuit in electrical isolation, the metal pot piece being overlaid on the outer ring circuit and the inner ring circuit, the outer ring circuit being electrically connected to a capacitive detection pin of a master control chip, and the inner ring circuit being connected to a ground end; the metal pot piece is in electrical connection with the outer ring circuit in normal state.
[0007] Preferably, the capacitance detection pin of the master chip supports function switching and can be configured between the capacitance sampling mode and the level sampling mode.
[0008] To solve the above technical problems, the application further discloses a recognition method based on the capacitive and physical composite key, which comprises the following steps: a master chip sets a key detection period and samples the capacitance detection pin; in the capacitance sampling mode, the capacitance value change of the pin is detected, and if the capacitance change exceeds a first preset threshold, it is determined that a touch event occurs and a touch signal is reported; in the level sampling mode, the level state of the pin is detected, and if a low level is detected, it is determined that a pressing event occurs and a pressing signal is reported.
[0009] After receiving the pressing signal, if the anti-mis-touch function is enabled, it is determined whether the touch signal is received in advance within a preset time window, if yes, it is determined that the pressing signal is valid, and if no, it is determined that the pressing signal is invalid.
[0010] Preferably, in the step of determining whether the touch signal is received in advance within a preset time window after receiving the pressing signal, if the anti-mis-touch function is not enabled, the pressing signal is directly determined to be valid after being received.
[0011] Preferably, in the step of detecting the capacitance value change of the pin in the capacitance sampling mode and determining that a touch event occurs and a touch signal is reported if the capacitance change exceeds a first preset threshold, after the touch signal is reported, if the system enables a key touch function, a corresponding system pre-response operation is triggered.
[0012] Preferably, in the step of setting a key detection period by a master chip and sampling a capacitance detection pin, the capacitance sampling mode or the level sampling mode is executed within one key detection period.
[0013] Preferably, in the step of setting a key detection period by a master chip and sampling a capacitance detection pin, the capacitance sampling mode and the level sampling mode are both detected within one key detection period.
[0014] Preferably, the switching between the capacitance sampling mode and the level sampling mode is realized by software configuring the pin function register of the master chip.
[0015] After the above-mentioned key and method, the capacitor and entity composite key includes a printed circuit board and a metal pot piece, the printed circuit board is provided with an outer ring circuit and an inner ring circuit which are electrically isolated from each other, the metal pot piece covers the outer ring circuit and the inner ring circuit, the outer ring circuit is electrically connected to a capacitor detection pin of a master control chip, and the inner ring circuit is connected to a ground end; the metal pot piece is electrically connected to the outer ring circuit in a normal state; the master control chip sets a key detection period and samples the capacitor detection pin; in a capacitor sampling mode, the capacitance value change of the pin is detected, if the capacitance change exceeds a first preset threshold, it is determined that a touch event occurs and a touch signal is reported; in a level sampling mode, the level state of the pin is detected, if a low level is detected, it is determined that a pressing event occurs and a pressing signal is reported; after receiving the pressing signal, if the anti-mis-touch function is enabled, it is judged whether the touch signal is received in advance within a preset time window, if yes, it is determined that the pressing signal is valid, if no, it is determined that the pressing signal is invalid;
[0016] The beneficial effects of the present application are:
[0017] 1. High reliability anti-mis-touch: through the logical judgment of "first capacitance touch signal and then level pressing signal", the mis-trigger caused by simple physical extrusion is fundamentally eliminated, and the reliability of key operation is greatly improved;
[0018] 2. Low hardware cost: the present application only needs to change the PCB wiring connection mode of the traditional pot piece key, without adding additional special capacitive sensors or complex circuits, fully utilizing the existing capacitance touch detection function of the master control chip, and realizing the extreme optimization of cost;
[0019] 3. Rich interactive experience: while realizing anti-mis-touch, an independent "touch" event detection is added. This makes the key can be touched by fingers when it is not pressed, providing the possibility of "prediction" or "preview" for the operating system, such as previewing notifications when the screen is on when touching, and unlocking only when pressing, significantly enriching the level and smoothness of human-computer interaction;
[0020] 4. High flexibility: through software configuration whether to start "anti-mis-touch detection" and "key light touch" function, users can choose flexibly according to their own use habits and environment, balancing safety and convenience. BRIEF DESCRIPTION OF DRAWINGS
[0021] Figure 1 is a circuit structure schematic diagram of a traditional pot piece key in the prior art;
[0022] Figure 2 is a circuit structure schematic diagram of the capacitor and entity composite key of the present application;
[0023] Figure 3 is a time sequence flow chart of the method for identifying the capacitive and physical composite key of the sixth embodiment of the present application, in which the time-sharing polling mode is used for sampling;
[0024] Figure 4 is a time sequence flow chart of the method for identifying the capacitive and physical composite key of the seventh embodiment of the present application, in which the same cycle is used for sampling the capacitance and the level. DETAILED DESCRIPTION
[0025] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.
[0026] Embodiment One
[0027] Please refer to Figure 2 , Figure 2 is a schematic diagram of the circuit structure of the capacitive and physical composite key described in the present application;
[0028] The present embodiment discloses a capacitive and physical composite key, which comprises a printed circuit board and a metal pot piece. The printed circuit board is provided with an outer ring circuit 1 and an inner ring circuit 2 which are electrically isolated from each other. The metal pot piece covers the outer ring circuit 1 and the inner ring circuit 2. The outer ring circuit 1 is electrically connected to a capacitive detection pin 3 of a master control chip. The inner ring circuit 2 is connected to a ground end. The metal pot piece is electrically connected to the outer ring circuit 1 in a normal state.
[0029] Embodiment Two
[0030] The present embodiment is based on embodiment one. In the present embodiment, the capacitive detection pin 3 of the master control chip supports function switching and can be configured between a capacitive sampling mode and a level sampling mode.
[0031] Embodiment Three
[0032] The present embodiment discloses a method for identifying a capacitive and physical composite key, which comprises the following steps: a master control chip sets a key detection cycle and samples a capacitive detection pin; in a capacitive sampling mode, a capacitive value change of the pin is detected. If the capacitive change exceeds a first preset threshold, it is determined that a touch event occurs and a touch signal is reported. In a level sampling mode, a level state of the pin is detected. If a low level is detected, it is determined that a pressing event occurs and a pressing signal is reported.
[0033] The master chip sets a fixed detection period (e.g. 5ms), in each period, the pin is first configured as a capacitive sampling mode. The master chip transmits an excitation signal to the inner ring circuit 2 and detects the capacitance value change (ΔC). When there is no touch, the capacitance baseline is stable; when the finger approaches or touches the key, the capacitance value at this place will increase due to the induction of the human body electric field. If ΔC exceeds the set touch threshold, the master chip determines that a touch event occurs, and reports this signal to the operating system. The operating system can trigger light touch functions such as preview, prompt, etc. according to user settings.
[0034] Subsequently, in the next sampling period of the master chip or the second half of the same period, the pin is switched to a digital level input mode. At this time, the master chip detects the level of the pin. In the normal state, since the potzai piece is only connected to the outer ring circuit 2 (capacitive pin), the pin level is uncertain or high level. When the key is pressed, the potzai piece deforms and simultaneously contacts the outer ring circuit 1 and the inner ring circuit 2, causing the capacitive detection pin 3 to be directly shorted to the ground, thereby being pulled low to a low level. When the master chip detects the low level, a press signal is generated and reported.
[0035] After receiving the press signal, if the anti-mis-touch function is enabled, it is judged whether the touch signal is previously received within a preset time window, if yes, it is determined that the press signal is valid, if no, it is determined that the press signal is invalid.
[0036] If it is enabled, the system queries the historical record to determine whether a touch signal from the same key is received within a recent period of time (e.g. 100ms). If yes, it means that this is a reasonable human operation sequence of "touch first and press later", and the press is determined to be valid, and the corresponding function (e.g. starting, volume adjustment) is executed. If no, it means that this press lacks the pre-action of "touch", and it is likely to be a mis-touch, and the system will discard it. If the "anti-mis-touch" function is not enabled, the system does not make a judgment, and directly responds to this press.
[0037] Embodiment Four
[0038] This embodiment is based on embodiment three. In this embodiment, in the step "after receiving the press signal, if the anti-mis-touch function is enabled, it is judged whether the touch signal is previously received within a preset time window, if yes, it is determined that the press signal is valid, if no, it is determined that the press signal is invalid", if the anti-mis-touch function is not enabled, the press signal is directly determined to be valid after being received.
[0039] Embodiment Five
[0040] The embodiment is based on embodiment three, in the embodiment, in the step of "in the capacitance sampling mode, detecting the capacitance value change of the pin, if the capacitance change exceeds the first preset threshold, determining that a touch event occurs and reporting a touch signal", after reporting the touch signal, if the system enables the key touch function, triggering the corresponding system pre-response operation.
[0041] Embodiment six
[0042] Please refer to Figure 3 , Figure 3 is the time sequence flow chart of the sampling in the recognition method of the capacitive and physical composite key of embodiment six of the application;
[0043] The embodiment is based on embodiment three, in the embodiment, in the step of "the master control chip sets the key detection period and samples the capacitance detection pin", the capacitance sampling mode or the level sampling mode is executed in one key detection period.
[0044] Embodiment seven
[0045] Please refer to Figure 4 , Figure 4 is the time sequence flow chart of the sampling in the recognition method of the capacitive and physical composite key of embodiment seven of the application;
[0046] The embodiment is based on embodiment three, in the embodiment, in the step of "the master control chip sets the key detection period and samples the capacitance detection pin", the capacitance sampling mode and the level sampling mode are both detected in one key detection period.
[0047] Embodiment eight
[0048] The embodiment is based on any one of embodiments three to seven, in the embodiment, the switching of the capacitance sampling mode and the level sampling mode is realized by software configuring the pin function register of the master control chip.
[0049] The application has the following advantages:
[0050] 1. High reliability of anti-mis-touch: through the logic judgment of "first capacitance touch signal and then level pressing signal", the mis-trigger caused by simple physical extrusion is fundamentally eliminated, and the reliability of key operation is greatly improved;
[0051] 2. Low hardware cost: the application only needs to change the PCB wiring connection mode of the traditional potzai piece key, without adding additional special capacitive sensors or complex circuits, fully utilizing the existing capacitance touch detection function of the master control chip, and realizing the extreme optimization of cost;
[0052] 3. Interactive experience is rich: while realizing the anti-mistouch, a separate "touch" event detection is added. This makes the key can be perceived finger touch when not pressed, providing the operating system with the possibility of "prediction" or "preview", such as previewing notifications when the screen is on, and unlocking when pressed, significantly enriching the level of human-computer interaction and smoothness;
[0053] 4. High flexibility: through software configuration whether to start "anti-mistouch detection" and "key light touch" function, users can choose flexibly according to their own use habits and environment, taking into account safety and convenience.
[0054] It should be understood that the above is only the preferred embodiment of the present application, and cannot limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.
Claims
1. A composite button combining a capacitor and a physical key, characterized in that, The device includes a printed circuit board and a metal dome switch. The printed circuit board has an outer ring circuit and an inner ring circuit that are electrically isolated from each other. The metal dome switch covers the outer ring circuit and the inner ring circuit. The outer ring circuit is electrically connected to the capacitance detection pin of the main control chip, and the inner ring circuit is connected to the ground terminal. Under normal conditions, the metal dome switch is electrically connected to the outer ring circuit.
2. The capacitive and physical composite button according to claim 1, characterized in that, The capacitance detection pin of the main control chip supports function switching and can be configured between capacitance sampling mode and level sampling mode.
3. A method for identifying a composite capacitive and physical button as described in claim 1, characterized in that, Includes the following steps: The main control chip sets the button detection cycle and samples the capacitance detection pin; In capacitance sampling mode, the change in capacitance value of the pin is detected. If the change in capacitance exceeds a first preset threshold, a touch event is determined to have occurred and a touch signal is reported. In level sampling mode, the level state of the pin is detected. If a low level is detected, a press event is determined to have occurred and a press signal is reported. After receiving the press signal, if the anti-accidental touch function is enabled, it is determined whether the touch signal has been received in advance within a preset time window. If so, the press signal is determined to be valid; otherwise, the press signal is determined to be invalid.
4. The method for recognizing a composite capacitive and physical button according to claim 3, characterized in that, In the step "After receiving the press signal, if the anti-mistouch function is enabled, determine whether the touch signal has been received in advance within a preset time window. If yes, determine that the press signal is valid; otherwise, determine that the press signal is invalid", if the anti-mistouch function is not enabled, then the press signal is directly determined to be valid after it is received.
5. The method for recognizing a composite capacitive and physical button according to claim 3, characterized in that, In the step "In capacitance sampling mode, detect the change in capacitance value of the pin. If the change in capacitance exceeds the first preset threshold, determine that a touch event has occurred and report the touch signal", after reporting the touch signal, if the system enables the button touch function, the corresponding system pre-response operation is triggered.
6. The method for recognizing a composite capacitive and physical button according to claim 3, characterized in that, In the step "the main control chip sets the key detection cycle and samples the capacitance detection pin", the capacitance sampling mode or the level sampling mode is executed within one key detection cycle.
7. The method for recognizing a composite capacitive and physical button according to claim 3, characterized in that, In the step "the main control chip sets the key detection cycle and samples the capacitance detection pin", both the capacitance sampling mode and the level sampling mode are detected within one key detection cycle.
8. The method for recognizing a capacitive and physical composite button according to any one of claims 3 to 7, characterized in that, The switching between the capacitance sampling mode and the level sampling mode is achieved by configuring the pin function registers of the main control chip through software.