An input detection device, system and pressure detection method

Abstract

An input detection device, system and pressure detection method, wherein the input detection device comprises: a cover plate, a PCB plate and a conductive body arranged in layers, and one or more capacitive sensors; the cover plate is attached to the top layer of the PCB plate, and the cover plate and the PCB plate are configured to deform under the action of an external force; the capacitive sensor is arranged on the bottom layer of the PCB plate; the capacitive sensor comprises: a center receiving electrode configured to sense an electric field; a transmitting electrode located on the same plane as the center receiving electrode and outside the center receiving electrode, configured to form an electric field, a first gap is formed between the transmitting electrode and the center receiving electrode, and a first capacitance value is formed between the center receiving electrode and the transmitting electrode in the absence of an external force; a gap is provided between the PCB plate and the conductive body, and the conductive body is configured to absorb part of the electric field formed by the transmitting electrode under the action of an external force, so that a second capacitance value is formed between the center receiving electrode and the transmitting electrode.

Description

Technical Field

[0001] This article relates to touch technology, and more particularly to an input detection device, system, and pressure detection method. Background Technology

[0002] Most existing capacitive pressure detection devices use parallel-plate capacitors as capacitive sensors. Under the action of an external force, the distance between the two plates of the parallel-plate capacitor changes, thereby changing the mutual capacitance between the two plates. The magnitude of the external force (i.e., pressure) is determined based on the change in mutual capacitance.

[0003] If the distance between the two plates is too small, the plates are prone to sticking together (pull-in) under overvoltage. Therefore, it is necessary to set mechanical limit posts or insulating particles, increase the thickness (Z direction) dimension, and occupy the space of the packaging cavity. Summary of the Invention

[0004] This application provides an input detection device, system, and pressure detection method.

[0005] The input detection device provided in this application embodiment includes: A cover plate, a PCB board, and conductors are stacked together, along with one or more capacitive sensors; The cover plate is attached to the top layer of the PCB board, and the cover plate and the PCB board are configured to deform under the action of external force; The capacitance sensor is disposed on the bottom layer of the PCB board; the capacitance sensor includes: a central receiving electrode configured to sense an electric field; a transmitting electrode located on the periphery of the central receiving electrode and on the same plane as the central receiving electrode, configured to form an electric field; a first gap is formed between the transmitting electrode and the central receiving electrode; and a first capacitance value is formed between the central receiving electrode and the transmitting electrode when no external force is applied. A gap is provided between the PCB board and the conductor. The conductor is configured to absorb part of the electric field formed by the transmitting electrode under the action of an external force, so that a second capacitance value is formed between the central receiving electrode and the transmitting electrode.

[0006] The input detection system provided in this application includes: The input detection device described in the embodiments of this application; A signal processing device electrically connected to the input detection device, the signal processing device being configured to determine the magnitude of an external force applied to the input detection device based on the difference between the first capacitance value and the second capacitance value; The signal processing device has a signal output channel and a signal receiving channel. The signal output channel is electrically connected to the central transmitting electrode of a capacitive sensor disposed on the bottom layer of the PCB board, and is used to output an excitation signal to the transmitting electrode to form an electric field. The signal receiving channel is electrically connected to the central receiving electrode of a capacitive sensor disposed on the bottom layer of the PCB board, and is used to receive a signal through the central receiving electrode to obtain the capacitance value formed between the central receiving electrode and the transmitting electrode.

[0007] The pressure detection method provided in this application embodiment is based on the input detection system described in this application embodiment, and the method includes: An excitation signal is emitted to the emitting electrode of the capacitive sensor, causing the emitting electrode to form an electric field; Receives a signal from the center receiving electrode of the capacitive sensor that senses the electric field output; The capacitance value between the central receiving electrode and the transmitting electrode is obtained based on the signal output by the electric field sensed by the central receiving electrode. Pressure detection is performed based on the capacitance value and the difference between the first capacitance value between the central receiving electrode and the transmitting electrode when no external force is applied.

[0008] The technical solution described in this application arranges the transmitting and receiving electrodes on the same horizontal plane. Compared to the parallel plate capacitor structure where the transmitting and receiving electrodes are arranged vertically opposite each other, this eliminates the need for the Z-axis structural space required for the electrode spacing, thus achieving a thinner and lighter input detection device. Furthermore, in conjunction with the placement of the conductor, this application also provides a pressure measurement mechanism based on a coplanar electrode structure. This allows the transmitting and receiving electrodes arranged on the same horizontal plane to generate a recognizable capacitive response when subjected to pressure, thereby providing technical assurance for the application of this structure in the field of pressure detection. Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application can be realized and obtained by means of the embodiments described in the description and the accompanying drawings. Attached Figure Description

[0009] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0010] Figure 1 This is a structural diagram of the input detection device provided in the embodiments of this application; Figure 2 A schematic diagram showing the capacitance change between the central receiving electrode and the transmitting electrode under conditions of external force and no external force pressing the cover plate, provided for an embodiment of this application. Figure 3 A schematic diagram of the shape of a capacitive sensor provided in an embodiment of this application; Figure 4 A schematic diagram of another capacitive sensor shape provided in an embodiment of this application; Figure 5 A schematic diagram of another capacitive sensor shape provided in an embodiment of this application; Figure 6 A schematic diagram illustrating the grouping of the transmitting electrode and the central receiving electrode of a capacitive sensor, and their connection to the signal output channel and the signal receiving channel in a signal processing device, provided for an embodiment of this application. Figure 7 A flowchart of the pressure detection method provided in the embodiments of this application; Figure 8 A diagram of the processing chip module provided in an embodiment of this application. Detailed Implementation

[0011] This application describes several embodiments, but these descriptions are exemplary and not limiting, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0012] This application includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this application can also be combined with any conventional features or elements to form unique inventive solutions. Any feature or element of any embodiment can also be combined with features or elements from other inventive solutions to form another unique inventive solution. Therefore, it should be understood that any feature shown and / or discussed in this application can be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes can be made within the scope of the appended claims.

[0013] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that it does not depend on such a specific order. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims concerning the method and / or process should not be limited to the steps performed in the written order, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments of this application.

[0014] This application provides an input detection device, such as... Figure 1 As shown, the input detection device includes: The cover plate 101, PCB board 102 and conductor 103 are stacked together, as well as one or more capacitive sensors; The cover plate 101 is attached to the top layer of the PCB board 102, and the cover plate 101 and the PCB board 102 are configured to deform under the action of external force; For example, the cover plate 101 is glass; the cover plate 101 and the PCB board 102 undergo elastic deformation under external force, and when the external force is removed, the cover plate and the PCB board can return to their initial state; Figure 1 In the diagram, the diagonal line between the cover plate 101 and the PCB board 102 represents the material that bonds the two together, such as glue; a common PCB board can be a 4-layer board, with the top layer being the 1st layer and the bottom layer being the 4th layer. The capacitance sensor is disposed on the bottom layer of the PCB board 102. The capacitance sensor includes a central receiving electrode 1041 and a transmitting electrode 1042. The central receiving electrode 1041 is configured to sense an electric field. The transmitting electrode 1042 is disposed around the central receiving electrode 1041 and is located on the same plane as the central receiving electrode 1041. It is configured to form an electric field. A first gap is formed between the transmitting electrode 1042 and the central receiving electrode 1041. In the absence of external force, a first capacitance value is formed between the central receiving electrode 1041 and the transmitting electrode 1042. When an external excitation signal (such as a high-frequency square wave) is applied to the transmitting electrode 102, an electric field can be formed around it. The central receiving electrode 1041 can obtain a coupling signal (such as charge / current) between the central receiving electrode 1041 and the transmitting electrode 1042 by sensing the electric field. The capacitance value between the central receiving electrode 1041 and the transmitting electrode 1042 can be obtained through this coupling signal. A gap is provided between the PCB board 102 and the conductor 103. The conductor 103 is configured to absorb part of the electric field formed by the transmitting electrode 1042 under the action of external force, so that a second capacitance value is formed between the central receiving electrode 1041 and the transmitting electrode 1042. When an external force is applied, the cover plate 101 and the PCB board 102 deform, causing the conductor 103 to move closer to the PCB board. The conductor 103 absorbs part of the electric field lines that originally connected the central receiving electrode 1041 and the transmitting electrode 1042, resulting in a weakening of the effective electric field coupling signal reaching the central receiving electrode 1041. The capacitance value between the central receiving electrode 1041 and the transmitting electrode 1042 decreases, that is, the second capacitance value is less than the first capacitance value.

[0015] When the input detection device is applied to the touch panel, if a metal plate is laid on the metal support located below the PCB board inside the touch panel, it can serve as the conductor 103 described in the embodiments of this application.

[0016] Figure 2 The changes in capacitance between the central receiving electrode and the transmitting electrode are shown under conditions of external force and without external force pressing the cover plate. Without external force pressing the cover plate, the capacitance between the central receiving electrode 1041 and the transmitting electrode 1042 is C0. An insulating medium exists between the transmitting electrode 1042 and the conductor 103, and a potential difference exists between them (the transmitting electrode is excited by a signal, and the conductor is grounded). Therefore, a capacitance C1 also exists between the transmitting electrode 1042 and the conductor 103. With external force pressing the cover plate, the distance between the PCB board 102 and the conductor 103 decreases (D1 < D0). The capacitance between the central receiving electrode 1041 and the transmitting electrode 1042 becomes C2, where C2 < C0. The capacitance between the transmitting electrode 1042 and the conductor 103 becomes C3, where C3 > C1.

[0017] The technical solution described in this application arranges the transmitting and receiving electrodes on the same horizontal plane. Compared to the parallel plate capacitor structure where the transmitting and receiving electrodes are arranged vertically opposite each other, this eliminates the need for the Z-axis structural space required for the electrode spacing, thus achieving a thinner and lighter input detection device. Furthermore, in conjunction with the placement of the conductor, this application also provides a pressure measurement mechanism based on a coplanar electrode structure. This enables the transmitting and receiving electrodes arranged on the same horizontal plane to generate a recognizable capacitive response when subjected to pressure, thereby providing technical assurance for the application of this structure in the field of pressure detection.

[0018] In one exemplary embodiment, such as Figure 1As shown, the capacitive sensor further includes a shielding electrode 1043 surrounding the emitting electrode 1042, configured to be at the same potential as the emitting electrode 1042, and a second gap is formed between the shielding electrode 1043 and the emitting electrode 1042.

[0019] This embodiment of the application eliminates the potential difference between the shielding electrode and the transmitting electrode by setting the shielding electrode 1043. This can cut off the path of the edge electric field of the transmitting electrode to the periphery, confine the electric field lines between the transmitting electrode and the central receiving electrode, and prevent external noise from interfering with the central receiving electrode and the transmitting electrode, thereby improving the measurement sensitivity.

[0020] In an exemplary embodiment, to achieve equipotentiality between the shielding electrode 1043 and the emitting electrode 1042, the shielding electrode 1043 and the emitting electrode 1042 can be connected via a voltage follower. The voltage follower can be implemented using an operational amplifier. By utilizing the high input impedance and low output impedance characteristics of the operational amplifier, the voltage follower transforms the shielding electrode into a mirror image of the emitting electrode potential, thereby eliminating parasitic capacitance in an equipotential manner, locking valuable electric field energy within the effective detection region, and improving the signal-to-noise ratio.

[0021] In one exemplary embodiment, such as Figure 1 As shown, the capacitive sensor further includes a ground electrode 1044 surrounding the shielding electrode 1043, and a third gap is formed between the ground electrode 1044 and the shielding electrode 1043.

[0022] There can be more than one capacitive sensor on the bottom layer of the PCB board. When there are multiple capacitive sensors, the grounding electrode 1044 can suppress electric field crosstalk between adjacent capacitive sensors and shield electromagnetic interference from the external environment. The electric field lines that have spread to this point are forcibly terminated and guided to the ground, and cannot continue to propagate.

[0023] The capacitive sensor described in the embodiments of this application can have various shapes. Figures 3-5 Schematic diagrams of different capacitive sensor shapes are shown. Figure 3 The central receiving electrode 1041 of the medium capacitance sensor is a solid circle, while the transmitting electrode 1042, shielding electrode 1043, and grounding electrode 1044 are all annular. Figure 4 The central receiving electrode 1041 of the medium capacitance sensor is a solid square, while the transmitting electrode 1042, shielding electrode 1043, and grounding electrode 1044 are all square rings. Figure 5 The central receiving electrode 1041 of the capacitive sensor is interdigitated, the transmitting electrode 1042 is interdigitated, the shielding electrode 1043 is a square ring, and the grounding electrode 1044 is a square ring. The shape of the capacitive sensor described in the embodiments of this application is not limited to the shape shown in the figures.

[0024] Considering the influence of factors such as temperature drift, power supply ripple, and equipment aging on the capacitive sensor, the reference capacitance value may shift. The reference capacitance value refers to the inherent capacitance value of the capacitive sensor when no external force is applied. To obtain the change in the reference capacitance value, in an exemplary embodiment, the input detection device further includes a reference capacitance sensor configured to collect the change in the reference capacitance value. For ease of distinction, this application embodiment classifies capacitive sensors into reference capacitance sensors and pressure-measuring capacitance sensors according to their function. In this application embodiment, the reference capacitance sensor and the pressure-measuring capacitance sensor have the same structure. The reference capacitance sensor is also disposed on the bottom layer of the PCB board. The position on the conductor opposite to the reference capacitance sensor is either hollowed out or has an insulating portion, so that even when an external force presses on the cover plate, the electric field lines between the central receiving electrode and the transmitting electrode will not change, ensuring that the capacitance value between the central receiving electrode and the transmitting electrode of the reference capacitance sensor is the reference capacitance value.

[0025] This application embodiment obtains the change in reference capacitance value by setting a reference capacitance sensor, which provides support for calibrating the output capacitance value of a capacitance sensor that has the same structure as the reference capacitance sensor for measuring pressure.

[0026] In one exemplary embodiment, the input detection device may further include: a touch detection sensor; The touch detection sensor is set on the top layer of the PCB board and is configured to detect touch actions on the cover plate, including: whether a touch action exists and the type of touch action.

[0027] The application embodiment can integrate touch detection and pressure measurement into the same output detection device, which has a high degree of integration and reduces BOM (Bill of Materials Cost).

[0028] The input detection device described in this application has a reasonable layout, can be directly adapted to existing PCB board making and assembly processes, and has a high degree of industrial mass production.

[0029] This application embodiment also provides an input detection system, the input detection system comprising: The input detection device as described in any of the foregoing embodiments of this application; A signal processing device electrically connected to the input detection device, the signal processing device being configured to determine the magnitude of an external force applied to the input detection device based on the difference between the first capacitance value and the second capacitance value; The signal processing device has a signal output channel and a signal receiving channel. The signal output channel is electrically connected to the central transmitting electrode of a capacitive sensor for measuring pressure, which is disposed on the bottom layer of the PCB board, and is used to output an excitation signal to the transmitting electrode to form an electric field. The signal receiving channel is electrically connected to the central receiving electrode of the capacitive sensor for measuring pressure, which is disposed on the bottom layer of the PCB board, and is used to receive a signal through the central receiving electrode to obtain the capacitance value formed between the central receiving electrode and the transmitting electrode.

[0030] The signal processing device can be implemented using integrated circuits (such as dedicated CDC chips), discrete analog / digital circuits, or a hardware system based on a processor and a memory storing corresponding programs.

[0031] In an exemplary embodiment, when there are multiple capacitive sensors for measuring pressure on the PCB board, the emitting electrodes of the multiple capacitive sensors for measuring pressure are divided into M groups, where M is greater than 1 and less than or equal to the total number of signal output channels in the signal processing device; in the M groups, the emitting electrodes of each group of capacitive sensors are connected in parallel to one of the signal output channels in the signal processing device, and the emitting electrodes of different groups of capacitive sensors are connected to different signal output channels in the signal processing device. The central receiving electrodes of the plurality of pressure measuring capacitive sensors are divided into N groups, and the central receiving electrodes of the plurality of pressure measuring capacitive sensors whose transmitting electrodes are in the same group are in different groups. N is greater than 1 and less than or equal to the total number of signal receiving channels in the signal processing device. In the N groups, the receiving electrodes of the capacitive sensors in different groups are electrically connected to different signal receiving channels in the signal processing device.

[0032] Figure 6 An example of grouping the transmitting electrodes and central receiving electrodes of six capacitive pressure sensors is given, as well as an example of connecting the transmitting electrodes and central receiving electrodes of these six capacitive pressure sensors to the signal output channel and signal receiving channel in the signal processing device.

[0033] like Figure 6 As shown, the emitting electrodes of these six capacitive sensors are divided into two groups of three electrodes each. The first group includes the emitting electrodes of capacitive sensors S1, S3, and S5, and the second group includes the emitting electrodes of capacitive sensors S2, S4, and S6. The emitting electrodes of capacitive sensors S1, S3, and S5 in the first group are connected in parallel to the TX1 pin of the signal processing device, and the emitting electrodes of capacitive sensors S2, S4, and S6 in the second group are connected in parallel to the TX2 pin of the signal processing device. The TX1 pin and the TX2 pin are different signal output channels in the signal processing device.

[0034] The central receiving electrodes of these six capacitive sensors are divided into three groups of two electrodes each. The first group includes the central receiving electrodes of capacitive sensors S1 and S4, the second group includes the central receiving electrodes of capacitive sensors S3 and S6, and the third group includes the central receiving electrodes of capacitive sensors S5 and S2. In the first group, the central receiving electrodes of capacitive sensors S1 and S4 are connected in parallel to the RX1 pin of the signal processing device. In the second group, the central receiving electrodes of sensors S3 and S6 are connected in parallel to the RX2 pin of the signal processing device. In the third group, the central receiving electrodes of sensors S2 and S5 are connected in parallel to the RX3 pin of the signal processing device. The RX1 pin, the RX2 pin, and the RX3 pin are different signal receiving channels in the signal processing device.

[0035] For example, within one sampling period (≤100μs), the signal processing device first turns on TX1 and sequentially or simultaneously samples or acquires the signals of the center receiving electrodes of capacitive sensors S1, S3, and S5; then turns off TX1 and turns on TX2, sequentially or simultaneously sampling or acquiring the signals of the center receiving electrodes of capacitive sensors S2, S4, and S6.

[0036] Taking a traditional touch chip as an example, this chip has 22 TX channels and 32 RX channels. If a traditional one-to-one connection method is used, six capacitive sensors would occupy six TX channels and six RX channels of the chip. However, with the connection method described above, only two TX channels and three RX channels of the chip are used, improving channel utilization.

[0037] remove Figure 6 In addition to the grouping methods recorded, there can be multiple other grouping methods, such as: In Method 1, the emitting electrodes of these 6 capacitive sensors are divided into 2 groups of 3 electrodes each. The first group includes the emitting electrodes of capacitive sensors S1, S3, and S5, and the second group includes the emitting electrodes of capacitive sensors S2, S4, and S6. In the first group, the emitting electrodes of capacitive sensors S1, S3, and S5 are connected in parallel to each other and connected to the TX1 pin of the signal processing device. In the second group, the emitting electrodes of capacitive sensors S2, S4, and S6 are connected in parallel to each other and connected to the TX2 pin of the signal processing device.

[0038] The central receiving electrodes of these six capacitive sensors are divided into three groups of two electrodes each. The first group includes the central receiving electrodes of capacitive sensors S1 and S2, the second group includes the central receiving electrodes of capacitive sensors S3 and S4, and the third group includes the central receiving electrodes of capacitive sensors S5 and S2. In the first group, the central receiving electrodes of capacitive sensors S1 and S2 are connected in parallel to each other and connected to the RX1 pin of the signal processing device. In the second group, the central receiving electrodes of sensors S3 and S4 are connected in parallel to each other and connected to the RX2 pin of the signal processing device. In the third group, the central receiving electrodes of sensors S5 and S6 are connected in parallel to each other and connected to the RX3 pin of the signal processing device.

[0039] Method 2: The emitting electrodes of these 6 capacitive sensors are divided into 3 groups, with 2 electrodes in each group. The first group includes the emitting electrodes of capacitive sensors S1 and S2, the second group includes the emitting electrodes of capacitive sensors S3 and S4, and the third group includes the emitting electrodes of capacitive sensors S5 and S6. In the first group, the emitting electrodes of capacitive sensors S1 and S2 are connected in parallel to each other and connected to the TX1 pin of the signal processing device. In the second group, the emitting electrodes of capacitive sensors S3 and S4 are connected in parallel to each other and connected to the TX2 pin of the signal processing device. In the third group, the emitting electrodes of capacitive sensors S5 and S6 are connected in parallel to each other and connected to the TX3 pin of the signal processing device.

[0040] The central receiving electrodes of these six capacitive sensors are divided into three groups of two electrodes each. The first group includes the central receiving electrodes of capacitive sensors S1 and S4, the second group includes the central receiving electrodes of capacitive sensors S2 and S5, and the third group includes the central receiving electrodes of capacitive sensors S3 and S6. In the first group, the central receiving electrodes of capacitive sensors S1 and S4 are connected in parallel to each other and connected to the RX1 pin of the signal processing device. In the second group, the central receiving electrodes of sensors S2 and S5 are connected in parallel to each other and connected to the RX2 pin of the signal processing device. In the third group, the central receiving electrodes of sensors S3 and S6 are connected in parallel to each other and connected to the RX3 pin of the signal processing device.

[0041] In an exemplary embodiment, when a reference capacitance sensor and a pressure measuring sensor are provided on the PCB board, the transmitting electrode of the reference capacitance sensor and the transmitting electrode of the pressure measuring capacitance sensor are electrically connected to the same or different signal output channels, respectively, and the central receiving electrode of the reference capacitance sensor and the central receiving electrode of the pressure measuring capacitance sensor are electrically connected to different signal receiving channels, respectively.

[0042] This application also provides a pressure detection method, which is based on the input detection system described in any embodiment of this application, such as... Figure 7 As shown, the method includes: Step S701: An excitation signal is transmitted to the transmitting electrode of the capacitive sensor to generate an electric field on the transmitting electrode. Step S702 receives the signal from the center receiving electrode of the capacitive sensor that senses the electric field output; Step S703: Based on the signal output by the electric field sensed by the central receiving electrode, obtain the capacitance value formed between the central receiving electrode and the transmitting electrode. Perform pressure detection based on the capacitance value and the difference between the first capacitance value formed between the central receiving electrode and the transmitting electrode when no external force is applied.

[0043] In an exemplary embodiment, the step of obtaining the capacitance value formed between the central receiving electrode and the transmitting electrode based on the signal output by the electric field sensed by the central receiving electrode, and performing pressure detection based on the difference between the capacitance value and a first capacitance value formed between the central receiving electrode and the transmitting electrode under the absence of external force, includes: Based on the signal output by the electric field sensed by the central receiving electrode, a second capacitance value is obtained between the central receiving electrode and the transmitting electrode under the action of external force; the difference between the first capacitance value and the second capacitance value is determined, and the magnitude of the pressure is determined based on the difference; this method corresponds to the case where the central receiving electrode outputs a signal under the action of external force, and no output signal when no external force is applied; the first capacitance value can be pre-stored; this method can be implemented in conjunction with a scheme that uses a touch detection sensor for touch detection, and only when a touch is determined to have occurred based on the output signal of the touch detection sensor, an excitation signal is applied to the capacitance sensor to trigger the capacitance sensor to work; Alternatively, if the difference between the first capacitance value and the capacitance value formed between the central receiving electrode and the transmitting electrode is greater than a preset difference threshold, pressure is determined to exist, and the magnitude of the pressure is determined based on the difference; if the difference between the first capacitance value and the capacitance value formed between the central receiving electrode and the transmitting electrode is less than or equal to the preset difference threshold, pressure is determined to not exist; this method corresponds to the case where the central receiving electrode outputs a signal whether or not an external force is applied.

[0044] In an exemplary embodiment, where the input detection system includes a reference capacitance sensor, the method further includes: Receives a signal from the center receiving electrode of the reference capacitance sensor; The change in reference capacitance value is determined based on the signal received from the center receiving electrode of the reference capacitance sensor. The difference is then calibrated based on the change in reference capacitance value, and the pressure magnitude is determined based on the calibrated difference.

[0045] The embodiments of this application can improve the accuracy of pressure calculation by calibrating the difference.

[0046] In one exemplary embodiment, the difference is calibrated based on the change in the reference capacitance value using the following formula: C_comp = C_meas - ΔC_ref - k× ΔV; Where C_comp is the difference after calibration, C_meas is the difference before calibration, ΔC_ref is the change in the reference capacitance value, k is the calibration coefficient (k≥0), and ΔV is the output offset of the operational amplifier follower in the input detection system. Through this calibration method, the change in capacitance between the center receiving electrode and the transmitting electrode of the capacitance sensor caused solely by external force can be obtained.

[0047] This application also provides a computer-readable storage medium storing one or more programs that can be executed by one or more processors to implement any of the pressure detection methods described in this application.

[0048] This application also provides a processing chip, such as... Figure 8 As shown, the processing chip includes: Storage module 801 is configured to store computer program instructions that can be executed on a processor; The processing module 802 is configured to execute the computer program instructions to implement any of the pressure detection methods described in the embodiments of this application.

[0049] It will be understood by those skilled in the art that all or some of the steps, systems, or apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit (ASIC). Such software may be distributed on a computer-readable medium, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term "computer storage medium" includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

Claims

1. An input detecting device characterized by comprising: The input detection device includes: A cover plate, a PCB board, and conductors are stacked together, along with one or more capacitive sensors; The cover plate is attached to the top layer of the PCB board, and the cover plate and the PCB board are configured to deform under the action of external force; The capacitance sensor is disposed on the bottom layer of the PCB board; the capacitance sensor includes: a central receiving electrode configured to sense an electric field; a transmitting electrode located on the periphery of the central receiving electrode and on the same plane as the central receiving electrode, configured to form an electric field; a first gap is formed between the transmitting electrode and the central receiving electrode; and a first capacitance value is formed between the central receiving electrode and the transmitting electrode when no external force is applied. A gap is provided between the PCB board and the conductor. The conductor is configured to absorb part of the electric field formed by the transmitting electrode under the action of an external force, so that a second capacitance value is formed between the central receiving electrode and the transmitting electrode.

2. The input detection device according to claim 1, characterized in that, The capacitive sensor further includes: a shielding electrode surrounding the emitting electrode, configured to be at the same potential as the emitting electrode, and a second gap forming between the shielding electrode and the emitting electrode; and A ground electrode surrounds the shielding electrode, and a third gap is formed between the ground electrode and the shielding electrode.

3. The input detection device according to any one of claims 1-2, characterized in that, The one or more capacitive sensors are configured to measure pressure; The input detection device further includes: A reference capacitance sensor is configured to acquire changes in a reference capacitance value, and the reference capacitance sensor has the same structure as a capacitance sensor for measuring pressure. The reference capacitance sensor is disposed on the bottom layer of the PCB board, and the position on the conductor opposite to the reference capacitance sensor is either hollowed out or has an insulating part.

4. An input detection system characterized by, The input detection system includes: The input detection device as described in any one of claims 1-2; A signal processing device electrically connected to the input detection device, the signal processing device being configured to determine the magnitude of an external force applied to the input detection device based on the difference between the first capacitance value and the second capacitance value; The signal processing device has a signal output channel and a signal receiving channel. The signal output channel is electrically connected to the central transmitting electrode of a capacitive sensor disposed on the bottom layer of the PCB board, and is used to output an excitation signal to the transmitting electrode to form an electric field. The signal receiving channel is electrically connected to the central receiving electrode of a capacitive sensor disposed on the bottom layer of the PCB board, and is used to receive a signal through the central receiving electrode to obtain the capacitance value formed between the central receiving electrode and the transmitting electrode.

5. The input detection system according to claim 4, characterized in that, The one or more capacitive sensors are configured to measure pressure; The input detection device further includes: A reference capacitance sensor is configured to acquire changes in a reference capacitance value, and the reference capacitance sensor has the same structure as a capacitance sensor for measuring pressure. The reference capacitance sensor is disposed on the bottom layer of the PCB board, and the position on the conductor opposite to the reference capacitance sensor is either hollowed out or has an insulating part. The transmitting electrode of the reference capacitance sensor and the transmitting electrode of the pressure measuring capacitance sensor are electrically connected to the same or different signal output channels, respectively. The central receiving electrode of the reference capacitance sensor and the central receiving electrode of the pressure measuring capacitance sensor are electrically connected to different signal receiving channels, respectively.

6. The input detection system according to claim 4, characterized in that, When there are multiple capacitive sensors on the PCB board, the emitting electrodes of the multiple capacitive sensors are divided into M groups, where M is greater than 1 and less than or equal to the total number of signal output channels in the signal processing device. In group M, the emitting electrodes of each group of capacitive sensors are connected in parallel to each other and electrically connected to one of the signal output channels of the signal processing device. The emitting electrodes of different groups of capacitive sensors are electrically connected to different signal output channels in the signal processing device. The central receiving electrodes of multiple capacitive sensors are divided into N groups, and the central receiving electrodes of multiple capacitive sensors whose transmitting electrodes are in the same group are in different groups. N is greater than 1 and less than or equal to the total number of signal receiving channels in the signal processing device. In the N groups, the receiving electrodes of different groups of capacitive sensors are electrically connected to different signal receiving channels in the signal processing device.

7. A pressure detection method, said method being based on the input detection system of any one of claims 4-6, said method comprising: An excitation signal is emitted to the emitting electrode of the capacitive sensor, causing the emitting electrode to form an electric field; Receives a signal from the center receiving electrode of the capacitive sensor that senses the electric field output; The capacitance value between the central receiving electrode and the transmitting electrode is obtained based on the signal output by the electric field sensed by the central receiving electrode. Pressure detection is performed based on the capacitance value and the difference between the first capacitance value between the central receiving electrode and the transmitting electrode when no external force is applied.

8. The method according to claim 7, characterized in that, The process of obtaining the capacitance value between the central receiving electrode and the transmitting electrode based on the signal output by the electric field sensed by the central receiving electrode, and performing pressure detection based on the capacitance value and the difference between the first capacitance value formed between the central receiving electrode and the transmitting electrode under no external force, includes: Based on the signal output by the electric field sensed by the central receiving electrode, a second capacitance value is obtained between the central receiving electrode and the transmitting electrode under the action of external force; the difference between the first capacitance value and the second capacitance value is determined, and the magnitude of the pressure is determined based on the difference; Alternatively, if the difference between the first capacitance value and the capacitance value formed between the central receiving electrode and the transmitting electrode is greater than a preset difference threshold, pressure is determined to exist, and the magnitude of the pressure is determined based on the difference; if the difference between the first capacitance value and the capacitance value formed between the central receiving electrode and the transmitting electrode is less than or equal to the preset difference threshold, pressure is determined to not exist.

9. The method according to claim 8, characterized in that, The method is based on the input detection system described in claim 5; The method further includes: Receives a signal from the center receiving electrode of the reference capacitance sensor; The change in reference capacitance value is determined based on the signal received from the center receiving electrode of the reference capacitance sensor. The difference is then calibrated based on the change in reference capacitance value, and the pressure magnitude is determined based on the calibrated difference.

10. The method according to claim 9, characterized in that, The difference is calibrated based on the change in the reference capacitance value, using the following formula: C_comp = C_meas - ΔC_ref - k× ΔV; Wherein, C_comp is the difference after calibration, C_meas is the difference before calibration, ΔC_ref is the change in the reference capacitance value, k is the calibration coefficient, k≥0, and ΔV is the output offset of the op-amp follower in the input detection system.

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