Press detection apparatus, touch-control chip and electronic device

Abstract

Provided in the embodiments of the present application are a press detection apparatus, a touch-control chip and an electronic device. The press detection apparatus comprises: a pressure sensor, a touch-control chip and a demodulation circuit, wherein the touch-control chip is electrically connected to the pressure sensor and an electrode in an electronic device; the pressure sensor is configured to generate a pressing signal when a pressing surface of the electronic device is pressed, and send the pressing signal to the touch-control chip; the touch-control chip is configured to generate a detection signal on the basis of the pressing signal, and send the detection signal to the demodulation circuit; and the demodulation circuit is configured to demodulate the detection signal to obtain an identification signal, and send the identification signal to a processing unit of the electronic device, such that the processing unit identifies a pressing operation on the basis of the identification signal. The touch-control chip in the press detection apparatus provided in the embodiments of the present application can be used for press detection and touch-control detection. There is no need to provide a separate press detection chip in the electronic device, and thus the cost is relatively low.

Description

Pressing detection device, touch chip and electronic device TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of electrical engineering, and particularly relate to a pressing detection device, a touch chip and an electronic device. BACKGROUND

[0002] With the increasing integration of electronic devices, the touch panel of the electronic device can integrate touch detection function and pressing detection function. When the user's finger touches the touch panel, the electronic device can recognize the touch instruction. When the user's finger presses the touch panel, the electronic device can recognize the pressing instruction.

[0003] At present, the electronic device recognizes the touch instruction through the touch chip and the electrode arranged in the electronic device, and recognizes the pressing instruction through the pressing detection chip and the pressure sensor arranged in the electronic device.

[0004] However, due to the high cost of the pressing detection chip and the touch chip, the electronic device integrating the touch detection function and the pressing detection function has a high cost.

[0005] SUMMARY

[0006] Therefore, embodiments of the present application provide a pressing detection device, a touch chip and an electronic device to at least partially solve the above problems.

[0007] According to a first aspect of embodiments of the present application, a pressing detection device is provided, comprising: a pressure sensor, a touch chip and a demodulation circuit; the touch chip is electrically connected with the pressure sensor and an electrode in the electronic device; the pressure sensor is configured to generate a pressing signal when a pressing surface of the electronic device is pressed, and send the pressing signal to the touch chip; the touch chip is configured to generate a detection signal according to the pressing signal, and send the detection signal to the demodulation circuit; the demodulation circuit is configured to demodulate the detection signal, obtain an identification signal, and send the identification signal to a processing unit of the electronic device, so that the processing unit recognizes a pressing operation according to the identification signal.

[0008] According to a second aspect of embodiments of the present application, a touch chip is provided, which is electrically connected with a pressure sensor and an electrode in an electronic device; the touch chip is configured to generate a detection signal according to a pressing signal generated by the pressure sensor when a pressing surface of the electronic device is pressed, and send the detection signal to a demodulation circuit, so that the demodulation circuit demodulates the detection signal, obtains an identification signal, and makes a processing unit recognize a pressing operation according to the identification signal.

[0009] According to a third aspect of the embodiments of the present application, an electronic device is provided, comprising an electrode, a processing unit and the pressing detection device according to the first aspect of the embodiments of the present application; the electrode is electrically connected with the touch chip in the pressing detection device, and the processing unit is electrically connected with the pressing detection device; the processing unit is configured to identify a pressing operation according to the identification signal sent by the pressing detection device.

[0010] According to the pressing detection device provided by the embodiments of the present application, the pressing detection device comprises a pressure sensor, a touch chip and a demodulation circuit, the touch chip is electrically connected with the electrode, so that the touch chip can perform touch detection through the sensing signal transmitted by the electrode, the pressure sensor can generate a pressing signal when the pressing surface is pressed, the touch chip can generate a detection signal according to the pressing signal, and the demodulation circuit can demodulate the detection signal to obtain an identification signal, so that the processing unit of the electronic device can identify a pressing operation. Since the touch chip is electrically connected with the electrode and the pressure sensor, the touch chip can perform touch detection and pressing detection. Compared with the pressing detection scheme in the prior art, the touch detection and the pressing detection can be realized by one touch chip, without the need to separately arrange a pressing detection chip, so that the cost is relatively low. In addition, since the demodulation circuit is arranged, the noise in the identification signal can be reduced, the signal-to-noise ratio of the identification signal can be improved, and the accuracy and sensitivity of the pressing detection can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the embodiments of the present application, and other drawings can also be obtained by those skilled in the art according to these drawings.

[0012] FIG. 1 is a schematic diagram of a pressing detection device provided by an embodiment of the present application;

[0013] FIG. 2 is a schematic diagram of a touch chip provided by an embodiment of the present application;

[0014] FIG. 3 is a schematic diagram of noise change provided by an embodiment of the present application;

[0015] FIG. 4 is a schematic diagram of a touch signal conversion unit provided by an embodiment of the present application;

[0016] FIG. 5 is a schematic diagram of a first pressing detection module provided by an embodiment of the present application;

[0017] FIG. 6 is a schematic diagram of another touch chip provided by an embodiment of the present application;

[0018] FIG. 7 is a schematic diagram of a pressure sensor provided by an embodiment of the present application;

[0019] FIG. 8 is a schematic diagram of another first pressing detection module according to an embodiment of the present application;

[0020] FIG. 9 is a schematic diagram of a first pressing detection module including a direct current bias according to an embodiment of the present application;

[0021] FIG. 10 is a schematic diagram of a signal processing unit including a filtering unit according to an embodiment of the present application;

[0022] FIG. 11 is a schematic diagram of a filtering unit according to an embodiment of the present application;

[0023] FIG. 12 is a schematic diagram of a signal processing unit including a sample and hold module according to an embodiment of the present application;

[0024] FIG. 13 is a schematic diagram of a signal processing unit including a buffer amplifier according to an embodiment of the present application;

[0025] FIG. 14 is a schematic diagram of a demodulation circuit according to an embodiment of the present application;

[0026] FIG. 15 is a schematic diagram of an IQ demodulation principle according to an embodiment of the present application;

[0027] FIG. 16 is a schematic diagram of an IQ demodulation bandwidth frequency response curve according to an embodiment of the present application;

[0028] FIG. 17 is a schematic diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] In order to make personnel in the art better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and in detail below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art should belong to the scope of protection of the embodiments of the present application.

[0030] As described above, with the increasing integration of electronic devices, the touch panel of the electronic device can integrate touch detection function and press detection function, for example, the touch panel of a notebook computer, the screen of a mobile phone and the like can support both touch detection function and press detection function, when the user's finger touches the touch panel, the electronic device can recognize touch instruction, when the user's finger presses the touch panel, the electronic device can recognize press instruction. At present, the electronic device recognizes touch instruction through the touch chip and electrode arranged in the electronic device, and recognizes press instruction through the press detection chip and pressure sensor arranged in the electronic device. However, due to the high cost of the press detection chip and the touch chip, the cost of the electronic device integrating the touch detection function and the press detection function is high.

[0031] In the embodiment of the present application, a press detection device is provided, which includes a pressure sensor, a touch chip and a demodulation circuit. The touch chip is electrically connected with the electrode, so that the touch chip can perform touch detection through the sensing signal transmitted by the electrode. The pressure sensor can generate a press signal when the press surface is pressed. The touch chip can generate a detection signal according to the press signal. The demodulation circuit can demodulate the detection signal to obtain a recognition signal. Thus, the processing unit of the electronic device can recognize the press operation. Since the touch chip is electrically connected with the electrode and the pressure sensor, the touch chip can perform touch detection and press detection. Compared with the press detection scheme in the prior art, the touch detection and the press detection can be realized by one touch chip without separately arranging a press detection chip, so the cost is low. Since the demodulation circuit is arranged, the noise in the recognition signal can be reduced, the signal-to-noise ratio of the recognition signal can be improved, and the accuracy and sensitivity of the press detection can be improved.

[0032] The press detection device provided in the present application will be described below through an embodiment.

[0033] Fig. 1 is a schematic diagram of a press detection device provided in the embodiment of the present application. The press detection device 100 is applied to an electronic device. As shown in Fig. 1, the press detection device 100 includes a pressure sensor 101, a touch chip 102 and a demodulation circuit 103. The touch chip 102 is electrically connected with the pressure sensor 101 and the electrode 201 in the electronic device. The pressure sensor 101 can generate a press signal when the press surface of the electronic device is pressed, and send the press signal to the touch chip 102. The touch chip 102 can generate a detection signal according to the press signal, and send the detection signal to the demodulation circuit 103. The demodulation circuit 103 can demodulate the detection signal to obtain a recognition signal, and send the recognition signal to the processing unit of the electronic device, so that the processing unit recognizes the press operation according to the recognition signal.

[0034] The pressing detection apparatus 100 comprises a pressure sensor 101, a touch chip 102 and a demodulation circuit 103. The touch chip 102 is electrically connected to the electrode 201 in the electronic device. The touch chip 102 can perform touch detection through the electrode 201. For example, the touch chip 102 can perform touch position detection according to the sensing signal generated by self-capacitance or mutual-capacitance of the electrode 201. The touch chip 102 is electrically connected to the pressure sensor 101 while being electrically connected to the electrode 201. In an example, the touch chip 102 can be electrically connected to the electrode 201 through a plurality of first pins and electrically connected to the pressure sensor 101 through a plurality of second pins. In another example, the touch chip 102 can be electrically connected to the pressure sensor 101 and the electrode 201 through a plurality of first pins. This is not limited herein.

[0035] When the pressing surface of the electronic device is pressed, for example, the touch screen is pressed, the touchpad is pressed, etc., the pressure sensor 101 generates a pressing signal and sends the pressing signal to the touch chip 102. The pressing signal can be a sine wave signal, a trapezoidal wave signal, etc. After receiving the pressing signal, the touch chip 102 processes the pressing signal, obtains a detection signal, and sends the detection signal to the demodulation circuit 103.

[0036] The demodulation circuit 103 can demodulate the detection signal sent by the touch chip 102. Specifically, the detection signal can be demodulated to determine the signal amplitude of the identification signal, and the identification signal can be generated according to the signal amplitude of the identification signal. In an example, the demodulation circuit 103 can perform narrowband demodulation on the detection signal to reduce the bandwidth of the noise, thereby improving the signal-to-noise ratio of the identification signal. After generating the identification signal, the demodulation circuit 103 sends the identification signal to the processing unit of the electronic device. After receiving the identification signal, the processing unit of the electronic device can identify the pressing operation according to the identification signal and perform corresponding operations. For example, according to the identified pressing operation, a click operation is performed, etc., or according to the identified pressing operation, the vibration unit is controlled to perform vibration feedback, etc. In an example, the demodulation circuit can be a digital demodulation circuit. In another example, the demodulation circuit can be an analog demodulation circuit.

[0037] In the embodiment of the present application, the pressing detection device 100 comprises a pressure sensor 101, a touch chip 102 and a demodulation circuit 103. The touch chip 102 is electrically connected with the electrode 201, so that the touch chip 102 can perform touch detection through the sensing signal transmitted by the electrode 201. The pressure sensor 101 can generate a pressing signal when the pressing surface is pressed. The touch chip 102 can generate a detection signal according to the pressing signal. The demodulation circuit 103 can demodulate the detection signal to obtain an identification signal, so that the processing unit of the electronic device can identify the pressing operation. Since the touch chip 102 is electrically connected with the electrode 201 and the pressure sensor 101, the touch chip 102 can perform touch detection and pressing detection. Compared with the pressing detection scheme in the prior art, the touch detection and the pressing detection can be realized by one touch chip 102, without the need to separately arrange a pressing detection chip, so that the cost is low. Since the demodulation circuit 103 is arranged, the noise in the identification signal can be reduced, the signal-to-noise ratio of the identification signal can be improved, and the accuracy and sensitivity of the pressing detection can be improved.

[0038] In a possible implementation, the touch chip 102 can perform touch detection through the electrode 201 in the touch detection mode, and perform pressing detection through the pressure sensor 101 in the pressing detection mode.

[0039] The touch chip 102 can switch between the touch detection mode and the pressing detection mode. When the touch chip 102 is in the touch detection mode, the touch chip 102 can perform touch detection through the electrode 201. In an example, the touch chip 102 can perform touch detection through the sensing signal generated by self-capacitance or mutual-capacitance of the electrode 201. When the touch chip 102 is in the pressing detection mode, the touch chip 102 can perform pressing detection through the pressure sensor 101, for example, through the pressing signal generated by the pressure sensor 101.

[0040] In the embodiment of the present application, the touch chip 102 can perform touch detection through the electrode 201 in the touch detection mode, and perform pressing detection through the pressure sensor 101 in the pressing detection mode, so that the touch chip 102 can realize touch detection and pressing detection. Compared with the pressing detection scheme in the prior art, the touch detection and the pressing detection can be realized by one touch chip 102, without the need to separately arrange a pressing detection chip, so that the cost is low.

[0041] In a possible implementation, the touch chip 102 can switch between the touch detection mode and the pressing detection mode according to a clock signal.

[0042] The touch chip 102 can switch the touch detection mode and the pressing detection mode according to the clock signal. Specifically, because the period of the touch detection is less than the period of the pressing detection, for example, the period of the touch detection is 20 ms and the period of the pressing detection is 50 ms, etc., when the time indicated by the clock signal reaches the time of the touch detection period, the touch chip 102 switches to the touch detection mode, and when the time indicated by the clock signal reaches the time of the pressing detection period, the touch chip 102 switches to the pressing detection mode.

[0043] In the embodiment of the present application, the touch chip 102 can switch the working mode between the touch detection mode and the pressing detection mode according to the clock signal, so that the touch detection can be performed when the touch detection period arrives and the pressing detection can be performed when the pressing detection period arrives, and the switching between the touch detection working mode and the pressing detection working mode is realized. Because the switching is performed according to the clock signal, the touch detection working mode and the pressing detection working mode can be prevented from interfering with each other, and the normal working of the touch chip 102 is ensured.

[0044] FIG. 2 is a schematic diagram of a touch chip according to an embodiment of the present application. As shown in FIG. 2, the touch chip 102 is connected with the electrode 201, the electrode 201 includes a plurality of horizontal electrodes and / or a plurality of vertical electrodes. In the touch detection mode, the touch chip 102 can send a first driving signal to one of the plurality of horizontal electrodes and the plurality of vertical electrodes, and perform touch position recognition according to a touch signal output by the other of the plurality of horizontal electrodes and the plurality of vertical electrodes, or the touch chip 102 can send a second driving signal to the driving electrode 201, and perform touch position recognition according to a touch signal output by the receiving electrode 201, wherein at least one of the plurality of horizontal electrodes and the plurality of vertical electrodes serves as both the driving electrode 201 and the receiving electrode 201.

[0045] One of the plurality of horizontal electrodes and the plurality of vertical electrodes serves as the driving electrode 201, and the touch chip 102 outputs the first driving signal to the driving electrode 201. The other of the plurality of horizontal electrodes and the plurality of vertical electrodes serves as the receiving electrode 201, and outputs a sensing signal. The touch chip 102 performs touch recognition according to the sensing signal, and can recognize the touch position of the finger. This mode is a mutual capacitance detection mode.

[0046] In addition, in another possible implementation, the self-capacitance detection mode can be superimposed to identify the touch position of the finger. At least one of the plurality of horizontal electrodes and the plurality of vertical electrodes serves as both the driving electrode 201 and the receiving electrode 201. The touch chip 102 sends a second driving signal to the driving electrode 201, and identifies the position according to the sensing signal output by the receiving electrode 201. For example, the touch chip 102 outputs a driving signal to the plurality of horizontal electrodes (driving electrode 201), and receives the sensing signal output by the plurality of horizontal electrodes (receiving electrode 201). Alternatively, the touch chip 102 outputs a driving signal to the plurality of vertical electrodes (driving electrode 201), and receives the sensing signal output by the plurality of vertical electrodes (receiving electrode 201). Alternatively, the touch chip 102 outputs a driving signal to the plurality of horizontal electrodes and the plurality of vertical electrodes, and receives the sensing signal output by the plurality of horizontal electrodes and the plurality of vertical electrodes. The touch chip 102 identifies the touch position according to the received sensing signal.

[0047] It should be understood that the first driving signal and the second driving signal can be a driving signal in a sine wave form, a driving signal in a square wave form, or a driving signal in a trapezoidal wave form, and the specific waveform of the driving signal is not limited herein.

[0048] In the embodiment of the present application, when the touch chip 102 is switched to the touch detection mode, the second driving signal or the third driving signal is output to the electrode 201, so that the sensing signal generated by the electrode 201 in the self-capacitance or mutual-capacitance mode is used to identify the touch position, thereby realizing the touch detection function, and the touch chip 102 can perform touch detection and press detection, so that a separate press detection chip is not required, and the cost is low.

[0049] In a possible implementation, the touch chip 102 can send a third driving signal to the pressure sensor 101 in the press detection mode, so that the pressure sensor 101 generates a press signal when the press surface of the electronic device is pressed.

[0050] When the touch chip 102 is in the press detection mode, the first driving signal or the second driving signal is stopped from being output to the electrode 201, and the electrode 201 does not generate a sensing signal at this time, that is, the electrode 201 does not generate a sensing signal when the press detection is performed. The touch chip 102 outputs a third driving signal to the pressure sensor 101. The third driving signal can be a driving signal in a sine wave form or a driving signal in a trapezoidal wave form. It should be understood that, because the signal frequency of the direct current signal is low, the low-frequency flicker noise in the press signal generated by the pressure sensor 101 is more, and because the lower the frequency, the greater the energy of the 1 / F noise, the use of the direct current driving signal can result in a low signal-to-noise ratio of the press signal.

[0051] In an example, FIG. 3 is a schematic diagram of noise variation, as shown in FIG. 3, at low frequency, 1 / F noise is the main noise, at medium frequency, 1 / F noise and white noise affect the signal at the same time, at high frequency, 1 / F noise can be ignored, and the main noise is white noise affecting the signal. Since the frequency of the direct current signal is low, the touch chip 102 adopts an AC driving signal, for example, a driving signal in a waveform of a string or a driving signal in a waveform of a ladder. Optionally, the touch chip 102 can output a third driving signal with a frequency of 1 kHz to 200 kHz to the pressure sensor 101. It should be understood that when the frequency of the driving signal is too high, the parasitic capacitance and the parasitic inductance of the pressure sensor 101 can generate noise affecting the pressing signal output by the pressure sensor 101. Specifically, when the frequency of the driving signal is too high, since the pressure sensor is in series with a variable resistor and a parasitic inductance and then in parallel with a parasitic capacitance, the inductive reactance of the inductance is S*L=2πfL. The capacitive reactance of the capacitance is 1 / S*C=1 / 2πfC, L represents the length of the inductance, f represents the frequency, and C represents the capacitance value. Therefore, the lower the frequency, the lower the inductive reactance of the parasitic inductance and the capacitive reactance of the parasitic capacitance, and the smaller the influence of the parasitic inductance and the parasitic capacitance on the signal generated by the variable resistor. Therefore, the frequency of the third driving signal is preferably as low as possible in the range of 1 kHz to 200 kHz. It should also be understood that the specific frequency of the third driving signal can be set as needed according to the specific situation of the pressure sensor 101, which is not limited herein.

[0052] In the embodiment of the present application, the touch chip 102 can send the third driving signal to the pressure sensor 101 in the pressing detection mode, so that the pressure sensor 101 generates a pressing signal when the pressing surface of the electronic device is pressed. Thus, the pressing detection function is realized, and the touch chip 102 can perform touch detection and pressing detection. Therefore, a separate pressing detection chip does not need to be arranged in the electronic device, and the cost is low.

[0053] In a possible implementation, the touch chip 102 includes a first switch group and a second switch group. When the switches in the first switch group are closed and the switches in the second switch group are open, the touch chip 102 works in the touch detection mode. When the switches in the first switch group are open and the switches in the second switch group are closed, the touch chip 102 works in the pressing detection mode.

[0054] The first switch group and the second switch group are included in the touch chip 102, and each of the first switch group and the second switch group includes a plurality of switches. When the switches in the first switch group are closed and the switches in the second switch group are opened, the touch chip 102 is switched to a touch detection mode, and at this time, the touch chip 102 can perform touch position recognition through the self-capacitance or mutual-capacitance sensing signals generated by the electrodes 201. When the first switch group is opened and the second switch group is closed, the touch chip 102 is switched to a pressing detection mode, and at this time, the touch chip 102 can perform pressing detection according to the pressing signals generated by the pressure sensor 101. It should be noted that, since the touch detection and the pressing detection are performed through the same chip and the touch detection and the pressing detection cannot be performed simultaneously, the on-off states of the switches in the first switch group and the second switch group are opposite.

[0055] In an example, the digital control unit in the touch chip 102 can control the on-off of the switches in the first switch group and the second switch group according to the clock signal, so that the touch chip 102 can switch the touch detection mode and the pressing detection mode according to the clock signal.

[0056] In the embodiment of the present application, the touch chip 102 can realize the switching between the touch detection mode and the pressing detection mode by controlling the on-off of the switches in the first switch group and the second switch group, so that the touch chip 102 can realize the touch detection function and the pressing detection function, and therefore, the electronic device does not need to separately arrange a pressing detection chip, and the cost is low.

[0057] In a possible implementation, the touch chip 102 includes a plurality of touch signal conversion units, the touch signal conversion units are electrically connected with the electrodes 201, and the touch signal conversion units can perform touch position detection through the electrodes 201 when the switches in the first switch group are closed and the switches in the second switch group are opened. When the first switch group is opened and the second switch group is closed, the three touch signal conversion units are electrically connected to form a first pressing detection module, two touch signal conversion units in the first pressing detection module are electrically connected with the pressure sensor 101, and the first pressing detection module can generate a detection signal according to the pressing signal.

[0058] The touch chip 102 includes a plurality of touch signal conversion units, each of the touch signal conversion units is connected with the electrodes 201, and different touch signal conversion units are connected with different electrodes 201, for example, a plurality of touch signal conversion units are connected with different horizontal electrodes and / or vertical electrodes. When the switches in the first switch group are closed and the switches in the second switch group are opened, the touch signal conversion units receive the sensing signals generated by the electrodes 201, convert the sensing signals into digital signals, and send the digital signals to a processing unit of an electronic device, so as to realize touch detection.

[0059] When the switches in the first switch group are turned off and the switches in the second switch group are turned on, the three touch signal conversion units are electrically connected to form a pressing signal conversion module, and the three touch signal conversion units can be any three touch signal conversion units, for example, the three touch signal conversion units can be adjacent three touch signal conversion units. It should be understood that the plurality of touch signal conversion units can form at least one first pressing detection module, and when the number of the first pressing detection modules is greater than 2, different first pressing detection modules include different touch signal conversion units. The number of the first pressing detection modules can be set as required and is not limited herein. The first pressing detection module is electrically connected to the output end of the pressure sensor 101, and two touch signal conversion units in the first pressing detection module are electrically connected to the output end of the touch signal conversion unit as the input end of the first pressing detection module. The two touch signal conversion units can receive the pressing signal generated by the pressure sensor 101, and the first pressing detection module converts the pressing signal into a detection signal.

[0060] In the embodiment of the present application, the touch chip 102 includes a plurality of touch signal conversion units. When the touch chip 102 is in a touch detection mode, the plurality of touch signal conversion units perform touch detection through the induced signal generated by the connected electrode 201, thereby realizing the touch detection function. When the touch chip 102 is switched to a pressing detection mode, three touch signal conversion units are electrically connected to form a first pressing detection module, the first pressing detection module receives the pressing signal generated by the pressure sensor 101, and performs pressing detection according to the pressing signal, thereby realizing the pressing detection function. Since the touch chip 102 realizes the touch detection function and the pressing detection function, it is not necessary to separately arrange a pressing detection chip, and the cost is low.

[0061] FIG. 4 is a schematic diagram of a touch signal conversion unit according to an embodiment of the present application. As shown in FIG. 4, the touch signal conversion unit includes an amplification unit 10201 and a first signal processing unit 10202. The amplification unit 10201 includes a first amplifier D1, a first resistor R1, a second resistor R2, a first feedback resistor Rf1, a second feedback resistor Rf2, a first capacitor C1, and a second capacitor C2.

[0062] The positive input end of the first amplifier D1 is electrically connected with the first end of the first feedback resistor Rf1, the second end of the first feedback resistor Rf1 is connected with the negative output end of the first amplifier D1, the first end of the first capacitor C1 is connected with the first end of the first feedback resistor Rf1, the second end of the first capacitor C1 is connected with the second end of the first feedback resistor Rf1, the first end of the second feedback resistor Rf2 is connected with the negative input end of the first amplifier D1, the second end of the second feedback resistor Rf2 is connected with the positive output end of the first amplifier D1, the first end of the second capacitor C2 is connected with the first end of the second feedback resistor Rf2, the second end of the second capacitor C2 is connected with the second end of the second feedback resistor Rf2, the first end of the first resistor R1 is connected with the negative output end of the first amplifier D1, the second end of the first resistor R1 is electrically connected with the first signal processing unit 10202, the first end of the second resistor R2 is connected with the positive output end of the first amplifier D1, and the second end of the second resistor R2 is electrically connected with the first signal processing unit 10202.

[0063] The first amplifier D1 in the touch signal conversion unit can generate a square wave signal according to the sensing signal generated by the electrode 201. In an example, the electrode 201 is electrically connected with the positive input end of the first amplifier D1, and a reference voltage, for example, a voltage controlled mixed integrated (VCMI), is electrically connected with the negative input end of the first amplifier D1. The positive input end of the first amplifier D1 receives the sensing signal generated by the electrode 201, and the sensing signal is a current signal. The identification current is converted into a square wave signal through a feedback resistor, a capacitor and the first amplifier D1. Specifically, the identification current acts on the feedback resistor, the first amplifier D1 identifies the voltage between the two ends of the feedback resistor, and compares the voltage with the reference voltage VCMI to generate a square wave signal. After the first amplifier D1 generates the square wave signal, the square wave signal is sent to the first signal processing unit 10202. The first signal processing unit 10202 can process the square wave signal to obtain a digital signal indicating a touch position, so that touch detection can be performed.

[0064] In the embodiment of the present application, the touch signal conversion unit includes an amplification unit 10201 and a first signal processing unit 10202. The sensing signal generated by the electrode 201 can be converted into a square wave signal through the amplification unit 10201, and the square wave signal can be processed through the first signal processing unit 10202, so that touch detection can be performed based on the processed signal. Thus, the touch signal conversion unit is used for touch detection, and the touch chip 102 can work in a touch detection mode.

[0065] Fig. 5 is a schematic diagram of a first pressing detection module according to an embodiment of the present application. As shown in Fig. 5, the first pressing detection module includes two first touch signal conversion units 1021 and one second touch signal conversion unit 1022.

[0066] The positive input terminal of the first amplifier D1 in the first touch signal conversion unit 1021 is connected with the first end of the first feedback resistor Rf1 through the first switch K1 in the first switch group, the first resistor R1 in the first touch signal conversion unit 1021 is electrically connected with the first input terminal of the first signal processing unit 10202 through the second switch K2 in the first switch group, the second resistor R2 in the first touch signal conversion unit 1021 is electrically connected with the second output terminal of the first signal processing unit 10202 through the third switch K3 in the first switch group, and the positive input terminals of the first amplifiers D1 in the two first touch signal conversion units 1021 are respectively electrically connected with the first output terminal and the second output terminal of the pressure sensor 101.

[0067] The positive input terminal of the first amplifier D1 in the second touch signal conversion unit 1022 is respectively connected with the first end of the fourth switch K4 in the second switch group and the first end of the fifth switch K5 in the second switch group, the second end of the fourth switch K4 is connected with the second end of the second resistor R2 in the first first touch signal conversion unit 1021, the second end of the fifth switch K5 is connected with the second end of the first resistor R1 in the second first touch signal conversion unit 1021, the negative input terminal of the first amplifier D1 in the second touch signal conversion unit 1022 is respectively connected with the first end of the sixth switch K6 in the second switch group and the first end of the seventh switch K7 in the second switch group, the second end of the sixth switch K6 is connected with the second end of the first resistor R1 in the first first touch signal conversion unit 1021, and the second end of the seventh switch K7 is connected with the second end of the second resistor R2 in the second first touch signal conversion unit 1021.

[0068] When the first switch group is disconnected and the second switch group is closed, the first switch K1, the second switch K2 and the third switch K3 are disconnected, the fourth switch K4, the fifth switch K5, the sixth switch K6 and the seventh switch K7 are closed, the first amplifier D1 in the first touch signal conversion unit 1021 sends the amplified pressing signal to the second touch signal conversion unit 1022, the first amplifier D1 in the second touch signal conversion unit 1022 converts the amplified pressing signal into a recognition voltage, and the first signal processing unit 10202 can receive the recognition voltage and convert the recognition voltage into a detection signal.

[0069] When the first switch group is opened, the electrical connection between the first amplifiers D1 in the first touch signal conversion units 1021 and the first signal processing units 10202 is disconnected, and the electrical connection between the first amplifiers D1 and the first feedback resistors Rf1 is disconnected, at this time, the first amplifiers D1 can be equivalent to a high-impedance amplifier, when the second switch group is closed, the first amplifiers D1 of the two first touch signal conversion units 1021 are electrically connected with the second touch signal conversion unit 1022, thereby combining a first pressing detection module.

[0070] The positive input end of the first amplifier D1 of the first touch signal conversion unit 1021 is electrically connected with the output end of the pressure sensor 101, the positive input end of the first amplifier D1 of the two first touch signal conversion units 1021 is respectively electrically connected with the first output end and the second output end of the pressure sensor 101, and the negative input end of the first amplifier D1 of the first touch signal conversion unit 1021 is connected with the reference voltage VCM1. After the first touch signal conversion unit 1021 receives the pressing signal generated by the pressure sensor 101, the pressing signal is amplified, and it should be understood that the amplified pressing signal is a square wave signal. Specifically, the first amplifier D1 of the first touch signal conversion unit 1021 compares the pressing signal input at the positive input end with the reference voltage VCM1 input at the negative input end, when the voltage of the pressing signal is greater than the reference voltage VCM1, the positive output end of the first amplifier D1 of the first touch signal conversion unit 1021 outputs a high-level signal, and the negative output end of the first amplifier D1 of the first touch signal conversion unit 1021 outputs a low-level signal, when the voltage of the pressing signal is less than the reference voltage VCM1, the positive output end of the first amplifier D1 of the first touch signal conversion unit 1021 outputs a low-level signal, and the negative output end of the first amplifier D1 of the first touch signal conversion unit 1021 outputs a high-level signal, thereby outputting a square wave signal. Since the first amplifier D1 of the first touch signal conversion unit 1021 can be equivalent to a high-impedance amplifier, and the two first touch signal conversion units 1021 are respectively connected with the output end of the pressure sensor 101, since the impedance of the first amplifier D1 is infinite, the current can be prevented from passing through the first amplifier D1, and the influence of the source impedance of the pressure sensor 101 on the detection signal can be avoided.

[0071] The positive input terminal of the first amplifier D1 of the second touch signal conversion unit 1022 receives the square wave signal output by the negative output terminal of the first first touch signal conversion unit 1021 and the square wave signal output by the positive output terminal of the second first touch signal conversion unit 1021, and the negative input terminal of the first amplifier D1 of the second touch signal conversion unit 1022 receives the square wave signal output by the positive output terminal of the first first touch signal conversion unit 1021 and the square wave signal output by the negative output terminal of the second first touch signal conversion unit 1021. It should be understood that the voltage of the first output terminal and the voltage of the second output terminal change differently when the pressure sensor 101 is pressed. Specifically, when the voltage of the first output terminal increases, the voltage of the second output terminal decreases, and when the voltage of the first output terminal decreases, the voltage of the second output terminal increases. Taking the case where the voltage of the first output terminal increases and the voltage of the second output terminal decreases as an example, when the voltage of the first output terminal increases, the voltage at the positive input terminal of the first amplifier D1 of the first first touch signal conversion unit 1021 is greater than the reference voltage VCMI, the positive output terminal outputs a high-level signal, and the negative output terminal outputs a low-level signal. Since the voltage of the second output terminal decreases, the voltage at the positive input terminal of the first amplifier D1 of the second first touch signal conversion unit 1021 is less than the reference voltage VCMI, the positive output terminal outputs a low-level signal, and the negative output terminal outputs a high-level signal. At this time, the positive input terminal of the first amplifier D1 of the second touch signal conversion unit 1022 inputs the superimposed low-level signal, and the negative input terminal inputs the superimposed high-level signal, thereby realizing signal superimposed input. The first amplifier D1 of the second touch signal conversion unit 1022 can generate a recognition voltage according to the voltage input by the positive input terminal and the negative input terminal. Specifically, the difference signal can be obtained by subtracting the signals of the two single-sided bridges as the recognition voltage, and the recognition voltage is a square wave signal. The first signal processing unit 10202 of the second touch signal conversion unit 1022 can process the recognition voltage to obtain a detection signal. In an example, the detection signal can be a digital signal.

[0072] When the first switch group is closed and the second switch group is open, the first switch K1, the second switch K2, and the third switch K3 are closed, the fourth switch K4, the fifth switch K5, the sixth switch K6, and the seventh switch K7 are open, the first amplifier D1 of the first touch signal conversion unit 1021 in the press signal detection module is electrically connected with the first signal processing unit 10202 of the first amplifier D1 of the first touch signal conversion unit 1021, the first amplifier D1 of the second touch signal conversion unit 1022 stops being electrically connected with the first amplifier D1 of the first touch signal conversion unit 1021, and the press signal detection module is decomposed into three touch signal conversion units. Thus, the touch detection mode can be switched, and the specific principle of touch detection can be referred to the description in the foregoing embodiments, which will not be described here.

[0073] In the embodiment of the present application, the first pressing detection module includes two first touch signal conversion units 1021 and one second touch signal conversion unit 1022. When the first switch group is disconnected and the second switch group is connected, the two first touch signal conversion units 1021 and the second touch signal conversion unit 1022 are electrically connected to form the first pressing detection module, so that the pressing detection can be realized. Since the first amplifier D1 in the first touch signal conversion unit 1021 can be equivalent to a high-impedance amplifier after the first pressing detection module is formed, the noise generated by the source impedance of the pressure sensor 101 can be avoided, the noise in the pressing detection can be reduced, and the signal-to-noise ratio of the detection signal can be increased. Since the pressing detection is performed through the touch signal conversion unit in the touch chip 102, the internal structure of the touch chip 102 does not need to be greatly changed, and a separate pressing detection chip does not need to be arranged, so that the cost can be reduced.

[0074] In a possible implementation, the touch chip 102 includes a plurality of touch detection units 1023 and a plurality of second pressing detection modules 1024. The touch detection unit 1023 can perform touch position detection through the electrode 201, and the second pressing detection module 1024 can generate a detection signal according to a pressing signal.

[0075] The touch chip 102 can include a plurality of touch detection units 1023 and a plurality of second pressing detection modules 1024. It should be understood that when the number of channels of the touch chip 102 receiving signals is large, the signals transmitted by the electrode 201 and the signals transmitted by the pressure sensor 101 can be received at the same time. Therefore, the touch chip 102 can simultaneously include a plurality of touch detection units 1023 and a plurality of second pressing detection modules 1024. The touch detection unit 1023 can perform touch position detection through the electrode 201, for example, the touch position detection can be performed through the self-capacitance and / or mutual-capacitance of the electrode 201 in the above embodiment, and the second pressing detection module 1024 can convert the pressing signal into a detection signal.

[0076] In the embodiment of the present application, the touch chip 102 includes a plurality of touch detection units 1023 and a plurality of second pressing detection modules 1024, so that the touch position detection and the pressing detection can be performed at the same time through the touch chip 102, without switching between the touch position detection and the pressing detection, thereby simplifying the process of the touch position detection and the pressing detection. Since the pressing detection function is realized through the touch chip 102, an additional pressing chip does not need to be arranged, and the cost is low.

[0077] Fig. 6 is a schematic view of another touch chip provided by the embodiment of the present application. As shown in Fig. 6, the touch detection unit 1023 includes a third amplifier D3, a fifth feedback resistor Rf5, a sixth feedback resistor Rf6, a seventh resistor R7, an eighth resistor R8, a twelfth capacitor C12, a thirteenth capacitor C13, and a second signal processing unit 10241. The positive input terminal of the third amplifier D3 is connected with the first end of the fifth feedback resistor Rf5 and the electrode 201 respectively, the second end of the fifth feedback resistor Rf5 is connected with the negative output terminal of the third amplifier D3, the first end of the twelfth capacitor C12 is connected with the first end of the fifth feedback resistor Rf5, the second end of the twelfth capacitor C12 is connected with the second end of the fifth feedback resistor Rf5, the first end of the sixth feedback resistor Rf6 is connected with the negative input terminal of the third amplifier D3, the second end of the sixth feedback resistor Rf6 is connected with the positive output terminal of the third amplifier D3, the first end of the thirteenth capacitor C13 is connected with the first end of the sixth feedback resistor Rf6, the second end of the thirteenth capacitor C13 is connected with the second end of the sixth feedback resistor Rf6, the first end of the seventh resistor R7 is connected with the negative output terminal of the third amplifier D3, the second end of the seventh resistor R7 is connected with the second signal processing unit 10241, the first end of the eighth resistor R8 is connected with the positive output terminal of the third amplifier D3, the second end of the eighth resistor R8 is connected with the second signal processing unit 10241, the second press detection module 1024 includes two first press detection units 10241 and one second press detection unit 10242.

[0078] The first press detection unit 10241 includes a fourth amplifier D4, a seventh feedback resistor Rf7, a ninth resistor R9, a tenth resistor R10, and a fourteenth capacitor C14, and the second press detection unit 10242 includes a fifth amplifier D5, an eighth feedback resistor Rf8, a ninth feedback resistor Rf9, an eleventh resistor R11, a twelfth resistor R12, a fifteenth capacitor C15, a sixteenth capacitor C16, and a third signal processing unit 102421. The first end of the seventh feedback resistor Rf7 is connected with the negative input terminal of the fourth amplifier D4, the second end of the seventh feedback resistor Rf7 is connected with the positive output terminal of the fourth amplifier D4, the first end of the fourteenth capacitor C14 is connected with the first end of the seventh feedback resistor Rf7, the second end of the fourteenth capacitor C14 is connected with the second end of the seventh feedback resistor Rf7, the first end of the ninth resistor R9 is connected with the negative output terminal of the fourth amplifier D4, the first end of the tenth resistor R10 is connected with the positive output terminal of the fourth amplifier D4, and the positive input terminals of the fourth amplifiers D4 in the two first press detection units 10241 are respectively connected with the first output terminal and the second output terminal of the pressure sensor 101.

[0079] The positive input end of the fifth amplifier D5 is connected with the first end of the eighth feedback resistor Rf8, the second end of the eighth feedback resistor Rf8 is connected with the negative output end of the fifth amplifier D5, the first end of the fifteenth capacitor C15 is connected with the first end of the eighth feedback resistor Rf8, the second end of the fifteenth capacitor C15 is connected with the second end of the eighth feedback resistor Rf8, the first end of the ninth feedback resistor Rf9 is connected with the negative input end of the fifth amplifier D5, the second end of the ninth feedback resistor Rf9 is connected with the positive output end of the fifth amplifier D5, the first end of the sixteenth capacitor C16 is connected with the first end of the ninth feedback resistor Rf9, the second end of the sixteenth capacitor C16 is connected with the second end of the ninth feedback resistor Rf9, the first end of the eleventh resistor R11 is connected with the negative output end of the fifth amplifier D5, the second end of the eleventh resistor R11 is electrically connected with the third signal processing unit 102421, the first end of the twelfth resistor R12 is connected with the positive output end of the fifth amplifier D5, the second end of the twelfth resistor R12 is electrically connected with the third signal processing unit 102421, the positive input end of the fifth amplifier D5 is connected with the second end of the tenth resistor R10 of the first first pressing detection unit 10241 and the second end of the ninth resistor R9 of the second first pressing detection unit 10241 respectively, and the negative input end of the fifth amplifier D5 is connected with the second end of the ninth resistor R9 of the first first pressing detection unit 10241 and the second end of the tenth resistor R10 of the second first pressing detection unit 10241 respectively.

[0080] The fourth amplifier D4 in the first pressing detection unit 10241 sends the amplified pressing signal to the second pressing detection unit 10242, and the fifth amplifier D5 in the second pressing detection unit 10242 converts the amplified pressing signal into an identification voltage.

[0081] The specific principles of the touch position detection and the pressing detection are similar to those described in the above embodiment, which will not be described here.

[0082] In the embodiment of the application, the above circuit connection relationship can realize the touch position detection and the pressing detection at the same time, the process of the touch position detection and the pressing detection is simplified because the switching between the touch position detection and the pressing detection is not needed, and the pressing detection function is realized by the touch chip 102, so that the pressing chip does not need to be additionally arranged, and the cost is low.

[0083] FIG. 7 is a schematic diagram of a pressure sensor provided in an embodiment of the application, as shown in FIG. 7, the pressure sensor 101 includes a first variable resistor Rv1, a second variable resistor Rv2, a third variable resistor Rv3 and a fourth variable resistor Rv4.

[0084] The first end of the first variable resistor Rv1 is connected with the power supply AC, the second end of the first variable resistor Rv1 is connected with the first end of the second variable resistor Rv2, the second end of the second variable resistor Rv2 is grounded, the first end of the third variable resistor Rv3 is connected with the power supply AC, the second end of the third variable resistor Rv3 is connected with the first end of the fourth variable resistor Rv4, the second end of the fourth variable resistor Rv4 is grounded, the second end of the first variable resistor Rv1 is connected with one of the two first touch signal conversion units 1021 as the first output end of the pressure sensor 101, the second end of the third variable resistor Rv3 is connected with the other of the two first touch signal conversion units 1021 as the second output end of the pressure sensor 101, the first variable resistor Rv1 and the fourth variable resistor Rv4 decrease in resistance when the pressure sensor 101 is deformed, the second variable resistor Rv2 and the third variable resistor Rv3 increase in resistance when the pressure sensor 101 is deformed, and a pressing signal is generated.

[0085] The pressure sensor 101 includes the first variable resistor Rv1, the second variable resistor Rv2, the third variable resistor Rv3 and the fourth variable resistor Rv4. When the pressing surface of the electronic device is pressed, the pressure sensor 101 is deformed, at this time, the first variable resistor Rv1 and the fourth variable resistor Rv4 are at least partially folded, the resistance decreases, the second variable resistor Rv2 and the third variable resistor Rv3 are at least partially stretched, the resistance increases, at this time, compared with when the pressure sensor 101 is not deformed, the output voltage of the first output end increases, and the output voltage of the second output end decreases. It should be understood that the above is only an example, specifically, when the pressure sensor 101 is deformed, the resistance of the first variable resistor Rv1 and the fourth variable resistor Rv4 can also increase, the resistance of the second variable resistor Rv2 and the third variable resistor Rv3 can also decrease, so that the output voltage of the first output end decreases, and the output voltage of the second output end increases. The specific way of generating the pressing signal is not limited here.

[0086] The first end of the first variable resistor Rv1 and the first end of the third variable resistor Rv3 are connected with the power supply AC. In an example, the power supply AC can be a touch chip 102, and the touch chip 102 outputs a third driving signal to the pressure sensor 101. In another example, the power supply AC can be an AC source, and the power supply AC outputs a driving signal in a sine wave form or a driving signal in a trapezoidal wave form to the first end of the first variable resistor Rv1 and the first end of the third variable resistor Rv3. The specific power supply AC is not limited here.

[0087] It should be understood that, for the second pressing detection module 1024 shown in FIG. 6, the connection mode of the pressure sensor 101 and the second pressing detection module 1024 is the same as the connection mode of the pressure sensor 101 and the first pressing detection module shown in FIG. 7, and details are not repeated here.

[0088] In the embodiment of the present application, the pressure sensor 101 comprises a first variable resistor Rv1, a second variable resistor Rv2, a third variable resistor Rv3 and a fourth variable resistor Rv4. When the pressure sensor 101 is deformed, the resistances of the first variable resistor Rv1, the second variable resistor Rv2, the third variable resistor Rv3 and the fourth variable resistor Rv4 change, so that the output voltages of the first output end and the second output end of the pressure sensor 101 change, thereby generating a pressing signal, so that the first pressing detection module can perform pressing detection through the pressing signal.

[0089] FIG. 8 is a schematic diagram of another pressing detection module provided by the embodiment of the present application. As shown in FIG. 8, the pressing detection module further comprises a third capacitor C3 and a fourth capacitor C4. The first end of the third capacitor C3 is connected with the first output end of the pressure sensor 101, and the second end of the third capacitor C3 is grounded. The first end of the fourth capacitor C4 is connected with the second output end of the pressure sensor 101, and the second end of the fourth capacitor C4 is grounded. The third capacitor C3 and the first variable resistor Rv1 constitute a first low-pass filter, and the fourth capacitor C4 and the second variable resistor Rv2 constitute a second low-pass filter. The first low-pass filter is used for low-pass filtering the output signal of the first output end of the pressure sensor 101, and the second low-pass filter is used for low-pass filtering the output signal of the second output end of the pressure sensor 101.

[0090] It should be understood that the pressing detection module can be the first pressing detection module and the second pressing detection module 1024. For the second pressing detection module 1024, the third capacitor C3 and the fourth capacitor C4 in the same position and connection relationship as in FIG. 8 can be arranged between the second pressing detection module 1024 and the pressure sensor 101, which will not be described here.

[0091] In the embodiment of the present application, adding the capacitors between the first output end and the second output end of the pressure sensor 101 and the ground wire can make the capacitors and the resistors in the pressure sensor 101 constitute low-pass filters, so that the pressing signal output by the pressure sensor 101 can be low-pass filtered, the harmonic signal can be attenuated, and the signal-to-noise ratio of the pressing signal can be increased.

[0092] Fig. 9 is a schematic diagram of a pressing detection module with DC bias according to an embodiment of the present application. As shown in Fig. 9, the pressing detection module further comprises a fifth capacitor C5, a sixth capacitor C6, a third resistor R3 and a fourth resistor R4. The first end of the fifth capacitor C5 is connected to the first output end of the pressure sensor 101, the second end of the fifth capacitor C5 is connected to the positive input end of the first amplifier D1 of the first touch signal conversion unit 1021, the first end of the third resistor R3 is connected to the power supply AC, the second end of the third resistor R3 is connected to the second end of the fifth capacitor C5, the first end of the sixth capacitor C6 is connected to the second output end of the pressure sensor 101, the second end of the sixth capacitor C6 is connected to the positive input end of the first amplifier D1 of the second touch signal conversion unit 1021, the first end of the fourth resistor R4 is connected to the power supply AC, the second end of the fourth resistor R4 is connected to the second end of the fifth capacitor C5. The fifth capacitor C5 and the third resistor R3 DC bias the output voltage of the first output end of the pressure sensor 101, and the sixth capacitor C6 and the fourth resistor R4 DC bias the output voltage of the second output end of the pressure sensor 101.

[0093] For the pressure sensor 101 in the above embodiment, when the DC bias is not set in the power supply AC connected to the first variable resistor Rv1 and the third variable resistor Rv3 in the pressure sensor 101, the fifth capacitor C5, the sixth capacitor C6, the third resistor R3 and the fourth resistor R4 can be set in the pressing detection module according to the above circuit connection relationship. Thus, the DC bias can be applied to the power supply AC connected to the first variable resistor Rv1 and the third variable resistor Rv3 in the pressure sensor 101, and the AC voltage of -n to n can be raised to 0-2n, so as to ensure that each amplifier in the pressure sensor 101 can work normally.

[0094] It should be understood that in the present scheme, the third capacitor C3 and the fourth capacitor C4 in the foregoing embodiment can also be added to low-pass filter the first output end and the second output end of the pressure sensor 101, which will not be described here.

[0095] It should be understood that the pressing detection module can be the first pressing detection module and the second pressing detection module 1024. For the second pressing detection module 1024, the fifth capacitor C5, the sixth capacitor C6, the third resistor R3 and the fourth resistor R4 in the same position and connection relationship as in Fig. 9 can be set between the second pressing detection module 1024 and the pressure sensor 101, which will not be described here.

[0096] In the embodiment of the present application, the pressing detection module further includes a fifth capacitor C5, a sixth capacitor C6, a third resistor R3 and a fourth resistor R4, so that the power supply AC connected with the pressure sensor 101 can be direct current biased by the fifth capacitor C5, the sixth capacitor C6, the third resistor R3 and the fourth resistor R4, the normal work of each amplifier in the pressing detection module is ensured, the pressing detection module can normally process the pressing signal, and the touch detection chip can normally perform pressing detection.

[0097] The signal processing unit is described below. It should be understood that the signal processing unit in any of the following embodiments can be the first signal processing unit 10202, the second signal processing unit 10231 and the third signal processing unit 102421 in the above embodiments.

[0098] In a possible implementation, the signal processing unit 10202 includes an analog-to-digital converter 102021, a first input end of the analog-to-digital converter 102021 is used as a first input end of the signal processing unit 10202, a second input end of the analog-to-digital converter 102021 is used as a second input end of the signal processing unit 10202, and the analog-to-digital converter 102021 can perform analog-to-digital conversion on the identification voltage.

[0099] In the embodiment of the present application, the signal processing unit 10202 includes the analog-to-digital converter 102021, and the analog signal output by the first amplifier D1 can be converted into a digital signal by the analog-to-digital converter 102021, so that the touch instruction or the pressing instruction can be identified according to the digital signal, the signal processing is realized, and the electronic device can identify the touch instruction and the pressing instruction.

[0100] FIG. 10 is a schematic diagram of a signal processing unit including a filtering unit according to an embodiment of the present application. As shown in FIG. 10, the signal processing unit 10202 further includes a filtering unit 102022, a first input end of the filtering unit 102022 is electrically connected with a second end of the first resistor R1, a second input end of the filtering unit 102022 is electrically connected with a second end of the second resistor R2, a first output end of the filtering unit 102022 is connected with a first input end of the analog-to-digital converter 102021, and a second output end of the filtering unit 102022 is connected with a second input end of the analog-to-digital converter 102021, and the filtering unit 102022 can perform low-pass filtering on the identification voltage to reduce external signal interference in the identification voltage.

[0101] In the embodiment of the present application, the signal processing unit 10202 further comprises a filtering unit 102022, so that the identification voltage can be low-pass filtered, external signal interference in the identification voltage is reduced, for example, out-of-band signal interference or signal noise is filtered out, while the Nyquist aliasing effect is prevented, the signal-to-noise ratio of the identification voltage input to the analog-to-digital converter 102021 is improved, the noise corresponding to the external signal interference in the identification signal converted by the analog-to-digital converter 102021 is small, the influence of the external signal interference on the touch identification or the press identification is reduced, and the accuracy and sensitivity of the touch identification or the press identification are improved.

[0102] FIG. 11 is a schematic diagram of a filtering unit according to an embodiment of the present application. As shown in FIG. 11, the filtering unit 102022 comprises a third feedback resistor Rf3, a fourth feedback resistor Rf4, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a fifth resistor R5, a sixth resistor R6, and a second amplifier D2. A first end of the third feedback resistor Rf3 serves as a first input end of the filtering unit 102022, a second end of the third feedback resistor Rf3 is connected with a positive input end of the second amplifier D2, a first end of the fourth feedback resistor Rf4 serves as a second input end of the filtering unit 102022, a second end of the fourth feedback resistor Rf4 is connected with a negative input end of the second amplifier D2, a negative output end of the second amplifier D2 serves as a first output end of the filtering unit 102022, and a positive output end of the second amplifier D2 serves as a second output end of the filtering unit 102022. A first end of the seventh capacitor C7 is connected with the first end of the third feedback resistor Rf3, a second end of the seventh capacitor C7 is connected with the first end of the fourth feedback resistor Rf4, a first end of the eighth capacitor C8 is connected with the second end of the third feedback resistor Rf3, a second end of the eighth capacitor C8 is connected with the negative output end of the second amplifier D2, a first end of the fifth resistor R5 is connected with the first end of the third feedback resistor Rf3, a second end of the fifth resistor R5 is connected with the negative output end of the second amplifier D2, a first end of the ninth capacitor C9 is connected with the second end of the fourth feedback resistor Rf4, a second end of the ninth capacitor C9 is connected with the positive output end of the second amplifier D2, a first end of the sixth resistor R6 is connected with the first end of the fourth feedback resistor Rf4, and a second end of the sixth resistor R6 is connected with the positive output end of the second amplifier D2.

[0103] In the embodiment of the present application, the low-pass filtering function is realized by the third feedback resistor Rf3, the fourth feedback resistor Rf4, the seventh capacitor C7, the eighth capacitor C8, the ninth capacitor C9, the fifth resistor R5, the sixth resistor R6 and the second amplifier D2, so that the identification voltage can be low-pass filtered, the external signal interference in the identification voltage is reduced, for example, the out-of-band signal interference or signal noise is filtered out, at the same time, the Nyquist aliasing effect can be prevented, the signal-to-noise ratio of the identification voltage input to the analog-to-digital converter 102021 is improved, the identification signal corresponding to the external signal interference in the identification signal converted by the analog-to-digital converter 102021 is reduced, the influence of the external signal interference on the touch identification or the press identification is reduced, and the accuracy and sensitivity of the touch identification or the press identification are improved.

[0104] FIG. 12 is a schematic diagram of a signal processing unit including a sample-and-hold module according to an embodiment of the present application. As shown in FIG. 12, the signal processing unit 10202 further includes a sample-and-hold module 102023. The sample-and-hold module 102023 includes an eighth switch K8, a ninth switch K9, a tenth switch K10, an eleventh switch K11, a tenth capacitor C10 and an eleventh capacitor C11. The first terminal of the eighth switch K8 is connected with the first output terminal of the filtering unit 102022. The second terminal of the eighth switch K8 is connected with the first terminal of the tenth capacitor C10 and the first terminal of the ninth switch K9 at the same time. The second terminal of the ninth switch K9 is connected with the first input terminal of the analog-to-digital converter 102021. The second terminal of the tenth capacitor C10 is grounded. The first terminal of the tenth switch K10 is connected with the second output terminal of the filtering unit 102022. The second terminal of the tenth switch K10 is connected with the first terminal of the eleventh capacitor C11 and the first terminal of the eleventh switch K11 at the same time. The second terminal of the eleventh switch K11 is connected with the second input terminal of the analog-to-digital converter 102021. The second terminal of the eleventh capacitor C11 is grounded. The sample-and-hold module 102023 can hold the identification voltage.

[0105] Since the inductive signal generated by the electrode 201 or the pressing signal generated by the pressure sensor 101 is a variable signal, the identification voltage output by the first amplifier D1, that is, the square wave signal, is a variable square wave signal. In order to ensure that all signals are input to the analog-to-digital converter 102021 for conversion into identification signals, a sample-and-hold circuit is provided. The sample-and-hold circuit can temporarily store the subsequent identification voltage when the analog-to-digital converter 102021 performs digital-to-analog conversion, so as to avoid missing part of the identification voltage due to the change of the identification voltage. Specifically, the ninth switch K9 and / or the eleventh switch K11 can be disconnected when the analog-to-digital converter 102021 performs digital-to-analog conversion, the identification voltage is temporarily stored in the tenth capacitor C10 and the eleventh capacitor C11, and when the analog-to-digital converter 102021 is idle, the eighth switch K8 and / or the tenth switch K10 are disconnected, the ninth switch K9 and / or the eleventh switch K11 are closed, so that the analog-to-digital converter 102021 receives the identification voltage temporarily stored in the capacitor. The eighth switch K8, the ninth switch K9, the tenth switch K10, the eleventh switch K11, the tenth capacitor C10 and the eleventh capacitor C11 realize the effect of sample-and-hold.

[0106] In the embodiment of the present application, the signal processing unit 10202 further includes a sample-and-hold module 102023. The sample-and-hold module 102023 can realize sample-and-hold of the identification voltage output by the first amplifier D1 through the eighth switch K8, the ninth switch K9, the tenth switch K10, the eleventh switch K11, the tenth capacitor C10 and the eleventh capacitor C11. Thus, the change of the identification voltage due to the change of the inductive signal or the pressing signal can be avoided, part of the identification voltage missed by the analog-to-digital converter 102021 can be avoided, all identification voltages converted by the analog-to-digital converter 102021 can be ensured to be identification signals, and the accuracy and sensitivity of touch identification or pressing identification are improved.

[0107] FIG. 13 is a schematic diagram of a signal processing unit including a buffer amplifier according to an embodiment of the present application. As shown in FIG. 13, the signal processing unit 10202 further includes a buffer amplifier D3. A first input end of the buffer amplifier D3 is connected with a second end of the ninth switch K9, a second input end of the buffer amplifier D3 is connected with a second end of the eleventh switch K11, a first output end of the buffer amplifier D3 is connected with a first input end of the analog-to-digital converter 102021, and a second output end of the buffer amplifier D3 is connected with a second input end of the analog-to-digital converter 102021. The buffer amplifier D3 is used for signal amplification processing of the identification voltage.

[0108] In the embodiment of the present application, the signal processing unit 10202 further includes a buffer amplifier D3, which can perform signal amplification on the identification voltage. The buffer amplifier D3 can be a level converter or a buffer, etc. Specifically, the high level in the identification voltage can be raised, and the low level can be lowered, so as to amplify the signal amplitude. Thus, the signal amplitude of the identification voltage input to the analog-to-digital converter 102021 can be large, avoiding the situation that the analog-to-digital converter 102021 cannot convert the identification voltage into an identification signal, so that the touch cannot be recognized or the press cannot be recognized, and the accuracy of touch recognition or press recognition is improved.

[0109] FIG. 14 is a schematic diagram of a demodulation circuit according to an embodiment of the present application. As shown in FIG. 14, the demodulation circuit 103 includes a first demodulation branch 1031 and a second demodulation branch 1032. The first demodulation branch 1031 is configured to perform sinusoidal demodulation on the detection signal to obtain a first identification sub-signal. The second demodulation branch 1032 is configured to perform cosine demodulation on the detection signal to obtain a second identification sub-signal. The demodulation circuit 103 is configured to generate an identification signal according to the first identification sub-signal and the second identification sub-signal.

[0110] The demodulation circuit 103 can be a logic circuit. The demodulation circuit 103 includes two branches. The first demodulation branch 1031 can perform sinusoidal demodulation on the detection signal to obtain an I component of the detection signal. The second demodulation branch 1032 can perform cosine demodulation on the detection signal to obtain a Q component of the detection signal. The signal amplitude of the identification signal can be obtained by calculating the square root of the sum of the square of the I component and the square of the Q component.

[0111] In an example, FIG. 15 is a schematic diagram of an IQ demodulation principle according to an embodiment of the present application. As shown in FIG. 15, the I component of the detection signal is equal to The Q component of the detection signal is equal to: Taking the square root of I3 and Q3, we have A is the signal amplitude of the identification signal, β is the phase information of the detection signal, β = arctan (I2 / Q2), and T is the driving time of the driving signal. Taking 100 ms as an example for the driving time, the width of the noise band is ±10 Hz. In an example, a digital window function operation, such as a Hamming window or a Hanning window, can be added between the analog-to-digital converter 102021 and the demodulation circuit 103 to avoid signal loss caused by truncation effect. FIG. 16 is a schematic diagram of an IQ demodulation bandwidth frequency response curve according to an embodiment of the present application. As shown in FIG. 16, the sidelobe width of the present scheme is 1 / T, and the main lobe width is 2 / T.

[0112] In the embodiment of the present application, the demodulation circuit 103 comprises a first demodulation branch 1031 and a second demodulation branch 1032, so that the detection signal can be IQ demodulated. Since the detection signal is IQ demodulated and the driving signal of the pressure sensor 101 is an AC signal, the 1 / F noise generated by the touch chip 102 when detecting the pressing can be reduced. Since the bandwidth of the IQ narrowband demodulation is very narrow, the in-band noise of the generated recognition signal can be reduced, the signal-to-noise ratio of the recognition signal can be improved, and the accuracy of the pressing recognition is improved.

[0113] The embodiment of the present application also provides a touch chip 102, which is electrically connected with the pressure sensor 101 and the electrode 201 in the electronic device. The touch chip 102 can generate a detection signal according to the pressing signal generated by the pressure sensor 101 when the pressing surface of the electronic device is pressed, and send the detection signal to the demodulation circuit 103, so that the demodulation circuit 103 demodulates the detection signal to obtain a recognition signal, and the processing unit recognizes the pressing operation according to the recognition signal.

[0114] It should be noted that the touch chip 102 can be the touch chip 102 in any of the above-mentioned embodiments, and the specific working principle in the touch chip 102 can be seen from the description in any of the above-mentioned embodiments, which will not be repeated here.

[0115] FIG. 17 is a schematic diagram of an electronic device according to an embodiment of the present application. As shown in FIG. 17, the electronic device 200 comprises an electrode 201, a processing unit 202 and a pressing detection apparatus 100 according to any of the above-mentioned embodiments. The electrode 201 is electrically connected with the touch chip 102 in the pressing detection apparatus 100, and the processing unit 202 is electrically connected with the pressing detection apparatus 100. The processing unit 202 is configured to recognize the pressing operation according to the recognition signal sent by the pressing detection apparatus 100.

[0116] The electrode 201 can be arranged in the pressing surface of the electronic device 200, for example, the electrode can be an electrode in a screen module, an electrode on a touchpad, etc. The processing unit 202 can be a processor in the electronic device 200 or a device with processing function in the electronic device 200, which is not limited here.

[0117] It should be understood that each embodiment in the specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other. Each embodiment focuses on the difference from other embodiments. Especially for the method embodiment, since it is basically similar to the method described in the device and system embodiments, the description is relatively simple, and the related parts can be referred to the description of other embodiments.

[0118] It is to be understood that the foregoing description is descriptive only, certain embodiments having been described in particularity. Other embodiments are within the scope of the claims. In some cases the acts or steps recited in the claims can be performed in a different order and still accomplish the desired results. Additionally, the processes depicted in the figures do not necessarily require the particular order shown, or sequential order to achieve the desired results. In certain implementations, multitasking and parallel processing can be advantageous or necessary.

[0119] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It is further understood that the terms "comprising," "including," "containing," and "having" and the like, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof. It is further understood that the terms "first," "second," "third," etc. are used herein merely for distinguishing between similar elements and are not necessarily used consistently in all contexts.

[0120] It is to be understood that the terms and expressions used herein are used as terms of description and not of limitation. There is no intention, therefore, of using the terms or expressions to exclude any equivalents of the features shown and described (or portions thereof). It is recognized that various modifications are possible within the scope of the claims and it is further understood that such modifications are intended to be within the scope of the claims. Other modifications, variations, and alternatives are also possible. Accordingly, the claims should be regarded as encompassing all such equivalents.

Claims

1. A press detection device applied to an electronic device, characterized in that, The device comprises a pressure sensor, a touch chip and a demodulation circuit; The touch chip is electrically connected with the pressure sensor and electrodes in the electronic device; The pressure sensor is configured to generate a pressing signal when a pressing surface of the electronic device is pressed, and send the pressing signal to the touch chip; The touch chip is configured to generate a detection signal according to the pressing signal, and send the detection signal to the demodulation circuit; The demodulation circuit is configured to demodulate the detection signal, obtain an identification signal, and send the identification signal to a processing unit of the electronic device, so that the processing unit identifies a pressing operation according to the identification signal.

2. The pressing detection device according to claim 1, wherein The touch chip is configured to perform touch detection through the electrodes in a touch detection mode, and perform pressing detection through the pressure sensor in a pressing detection mode.

3. The pressing detection device according to claim 2, wherein The touch chip is configured to switch the working mode between the touch detection mode and the pressing detection mode according to a clock signal.

4. The press detection device according to claim 2, characterized by The electrodes comprise a plurality of horizontal electrodes and / or a plurality of vertical electrodes; The touch chip is configured to send a first driving signal to one of the plurality of horizontal electrodes and the plurality of vertical electrodes in the touch detection mode, and perform touch position identification according to a touch signal output by the other of the plurality of horizontal electrodes and the plurality of vertical electrodes; Alternatively, The touch chip is configured to send a second driving signal to a driving electrode, and perform touch position identification according to a touch signal output by a receiving electrode, wherein at least one of the plurality of horizontal electrodes and the plurality of vertical electrodes serves as both the driving electrode and the receiving electrode.

5. The pressing detection device according to claim 2, wherein The touch chip is configured to send a third driving signal to the pressure sensor in the pressing detection mode, so that the pressure sensor generates a pressing signal when the pressing surface of the electronic device is pressed.

6. The push detection apparatus according to claim 2, wherein The touch chip comprises a first switch group and a second switch group, and the touch chip works in the touch detection mode when switches in the first switch group are closed and switches in the second switch group are open, and the touch chip works in the pressing detection mode when the first switch group is open and the second switch group is closed.

7. The push detection device according to claim 6, wherein The touch chip comprises a plurality of touch signal conversion units, and the touch signal conversion units are electrically connected with the electrodes; The touch signal conversion units are configured to perform touch position detection through the electrodes when the switches in the first switch group are closed and the switches in the second switch group are open; When the first switch group is open and the second switch group is closed, three of the touch signal conversion units are electrically connected to form a first pressing detection module, and two of the touch signal conversion units in the first pressing detection module are electrically connected with the pressure sensor; The first pressing detection module is configured to generate the detection signal according to the pressing signal.

8. The push detection apparatus according to claim 7, wherein The touch signal conversion unit comprises an amplification unit and a first signal processing unit; The amplification unit comprises a first amplifier, a first resistor, a second resistor, a first feedback resistor, a second feedback resistor, a first capacitor and a second capacitor; The positive input end of the first amplifier is electrically connected with the first end of the first feedback resistor, the second end of the first feedback resistor is connected with the negative output end of the first amplifier, the first end of the first capacitor is connected with the first end of the first feedback resistor, the second end of the first capacitor is connected with the second end of the first feedback resistor, the first end of the second feedback resistor is connected with the negative input end of the first amplifier, the second end of the second feedback resistor is connected with the positive output end of the first amplifier, the first end of the second capacitor is connected with the first end of the second feedback resistor, the second end of the second capacitor is connected with the second end of the second feedback resistor, the first end of the first resistor is connected with the negative output end of the first amplifier, the second end of the first resistor is electrically connected with the first signal processing unit, the first end of the second resistor is connected with the positive output end of the first amplifier, and the second end of the second resistor is electrically connected with the first signal processing unit. The first pressing detection module comprises two first touch signal conversion units and one second touch signal conversion unit; 9. The push detection apparatus according to claim 8, wherein The positive input end of the first amplifier in the first touch signal conversion unit is connected with the first end of the first feedback resistor through the first switch in the first switch group, the first resistor in the first touch signal conversion unit is electrically connected with the first output end of the first signal processing unit through the second switch in the first switch group, the second resistor in the first touch signal conversion unit is electrically connected with the second output end of the first signal processing unit through the third switch in the first switch group, and the positive input end of the first amplifier in the two first touch signal conversion units is respectively electrically connected with the first output end and the second output end of the pressure sensor; The positive input end of the first amplifier of the second touch signal conversion unit is respectively connected with the first end of the fourth switch in the second switch group and the first end of the fifth switch in the second switch group, the second end of the fourth switch is connected with the second end of the second resistor in the first first touch signal conversion unit, the second end of the fifth switch is connected with the second end of the first resistor in the second first touch signal conversion unit, the negative input end of the first amplifier of the second touch signal conversion unit is respectively connected with the first end of the sixth switch in the second switch group and the first end of the seventh switch in the second switch group, the second end of the sixth switch is connected with the second end of the first resistor in the first first touch signal conversion unit, and the second end of the seventh switch is connected with the second end of the second resistor in the second first touch signal conversion unit. ​ When the first switch group is off and the second switch group is on, the first switch, the second switch and the third switch are off, the fourth switch, the fifth switch, the sixth switch and the seventh switch are on, the first amplifier in the first touch signal conversion unit sends the amplified press signal to the second touch signal conversion unit, the first amplifier in the second touch signal conversion unit converts the amplified press signal into an identification voltage, and the first signal processing unit receives the identification voltage and converts the identification voltage into the detection signal.

10. The push detection apparatus according to claim 1, wherein The touch chip comprises a plurality of touch detection units and a plurality of second press detection modules. The touch detection unit is configured to detect a touch position through the electrode. The second press detection module is configured to generate the detection signal according to the press signal.

11. The press detection device according to claim 10, wherein The touch detection unit comprises a third amplifier, a fifth feedback resistor, a sixth feedback resistor, a seventh resistor, an eighth resistor, a twelfth capacitor, a thirteenth capacitor and a second signal processing unit. The positive input end of the third amplifier is electrically connected with the first end of the fifth feedback resistor and the electrode respectively, the second end of the fifth feedback resistor is connected with the negative output end of the third amplifier, the first end of the twelfth capacitor is connected with the first end of the fifth feedback resistor, the second end of the twelfth capacitor is connected with the second end of the fifth feedback resistor, the first end of the sixth feedback resistor is connected with the negative input end of the third amplifier, the second end of the sixth feedback resistor is connected with the positive output end of the third amplifier, the first end of the thirteenth capacitor is connected with the first end of the sixth feedback resistor, the second end of the thirteenth capacitor is connected with the second end of the sixth feedback resistor, the first end of the seventh resistor is connected with the negative output end of the third amplifier, the second end of the seventh resistor is electrically connected with the second signal processing unit, the first end of the eighth resistor is connected with the positive output end of the third amplifier, and the second end of the eighth resistor is electrically connected with the second signal processing unit. The second press detection module comprises two first press detection units and one second press detection unit, the first press detection unit comprises a fourth amplifier, a seventh feedback resistor, a ninth resistor, a tenth resistor and a fourteenth capacitor, and the second press detection unit comprises a fifth amplifier, an eighth feedback resistor, a ninth feedback resistor, an eleventh resistor, a twelfth resistor, a fifteenth capacitor, a sixteenth capacitor and a third signal processing unit. The first end of the seventh feedback resistor is connected with the negative input end of the fourth amplifier, the second end of the seventh feedback resistor is connected with the positive output end of the fourth amplifier, the first end of the fourteenth capacitor is connected with the first end of the seventh feedback resistor, the second end of the fourteenth capacitor is connected with the second end of the seventh feedback resistor, the first end of the ninth resistor is connected with the negative output end of the fourth amplifier, the first end of the tenth resistor is connected with the positive output end of the fourth amplifier, the positive input end of the fourth amplifier in the fourth first pressing detection unit is respectively connected with the first output end and the second output end of the pressure sensor; The positive input end of the fifth amplifier is connected with the first end of the eighth feedback resistor, the second end of the eighth feedback resistor is connected with the negative output end of the fifth amplifier, the first end of the fifteenth capacitor is connected with the first end of the eighth feedback resistor, the second end of the fifteenth capacitor is connected with the second end of the eighth feedback resistor, the first end of the ninth feedback resistor is connected with the negative input end of the fifth amplifier, the second end of the ninth feedback resistor is connected with the positive output end of the fifth amplifier, the first end of the sixteenth capacitor is connected with the first end of the ninth feedback resistor, the second end of the sixteenth capacitor is connected with the second end of the ninth feedback resistor, the first end of the eleventh resistor is connected with the negative output end of the fifth amplifier, the second end of the eleventh resistor is connected with the third signal processing unit, the first end of the twelfth resistor is connected with the positive output end of the fifth amplifier, the second end of the twelfth resistor is connected with the third signal processing unit, the positive input end of the fifth amplifier is respectively connected with the second end of the tenth resistor of the first first pressing detection unit and the second end of the ninth resistor of the second first pressing detection unit, the negative input end of the fifth amplifier is respectively connected with the second end of the ninth resistor of the first first pressing detection unit and the second end of the tenth resistor of the second first pressing detection unit; The fourth amplifier in the first pressing detection unit sends the amplified pressing signal to the second pressing detection unit, the fifth amplifier in the second pressing detection unit converts the amplified pressing signal into an identification voltage, and the third signal processing unit is used for receiving the identification voltage and converting the identification voltage into the detection signal. The pressure sensor comprises a first variable resistor, a second variable resistor, a third variable resistor and a fourth variable resistor; 12. The press detection apparatus according to claim 9, characterized by The first end of the first variable resistor is connected with a power supply, the second end of the first variable resistor is connected with the first end of the second variable resistor, the second end of the second variable resistor is grounded, the first end of the third variable resistor is connected with the power supply, the second end of the third variable resistor is connected with the first end of the fourth variable resistor, and the second end of the fourth variable resistor is grounded. ​ A second end of the first variable resistor is used as a first output end of the pressure sensor, and a second end of the third variable resistor is used as a second output end of the pressure sensor. The first variable resistor and the fourth variable resistor have a decreased resistance when the pressure sensor is deformed, and the second variable resistor and the third variable resistor have an increased resistance when the pressure sensor is deformed, thereby generating the pressing signal.

13. The push detection apparatus according to claim 12, wherein The pressing detection module further comprises a third capacitor and a fourth capacitor. A first end of the third capacitor is connected to the first output end of the pressure sensor, and a second end of the third capacitor is grounded. A first end of the fourth capacitor is connected to the second output end of the pressure sensor, and a second end of the fourth capacitor is grounded. The third capacitor and the first variable resistor form a first low-pass filter, and the fourth capacitor and the second variable resistor form a second low-pass filter. The first low-pass filter is used for low-pass filtering an output signal of the first output end of the pressure sensor, and the second low-pass filter is used for low-pass filtering an output signal of the second output end of the pressure sensor.

14. The press detection apparatus according to claim 12, wherein The pressing detection module further comprises a fifth capacitor, a sixth capacitor, a third resistor and a fourth resistor. A first end of the fifth capacitor is connected to the first output end of the pressure sensor, a second end of the fifth capacitor is connected to a positive input end of the first amplifier of the first first touch signal conversion unit, a first end of the third resistor is connected to the power supply, and a second end of the third resistor is connected to the second end of the fifth capacitor. A first end of the sixth capacitor is connected to the second output end of the pressure sensor, a second end of the sixth capacitor is connected to a positive input end of the first amplifier of the second first touch signal conversion unit, a first end of the fourth resistor is connected to the power supply, and a second end of the fourth resistor is connected to the second end of the fifth capacitor. The fifth capacitor and the third resistor are used for direct current biasing of an output voltage of the first output end of the pressure sensor, and the sixth capacitor and the fourth resistor are used for direct current biasing of an output voltage of the second output end of the pressure sensor.

15. The press detection apparatus according to claim 9, characterized by The first signal processing unit comprises an analog-to-digital converter. A first input end of the analog-to-digital converter is used as a first input end of the first signal processing unit. A second input end of the analog-to-digital converter is used as a second input end of the first signal processing unit. The analog-to-digital converter is used for analog-to-digital conversion of the identification voltage.

16. The press detection apparatus according to claim 15, wherein The first signal processing unit further comprises a filter unit. A first input end of the filter unit is electrically connected to the second end of the first resistor, a second input end of the filter unit is electrically connected to the second end of the second resistor, a first output end of the filter unit is connected to the first input end of the analog-to-digital converter, and a second output end of the filter unit is connected to the second input end of the analog-to-digital converter. The filter unit is used for low-pass filtering of the identification voltage, so as to reduce external signal interference in the identification voltage.

17. The press detection apparatus according to claim 16, characterized by The filter unit comprises a third feedback resistor, a fourth feedback resistor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a fifth resistor, a sixth resistor and a second amplifier; a first end of the third feedback resistor is used as a first input end of the filter unit, a second end of the third feedback resistor is connected with a positive input end of the second amplifier, a first end of the fourth feedback resistor is used as a second input end of the filter unit, a second end of the fourth feedback resistor is connected with a negative input end of the second amplifier, a negative output end of the second amplifier is used as a first output end of the filter unit, and a positive output end of the second amplifier is used as a second output end of the filter unit; a first end of the seventh capacitor is connected with the first end of the third feedback resistor, and a second end of the seventh capacitor is connected with the first end of the fourth feedback resistor; a first end of the eighth capacitor is connected with the second end of the third feedback resistor, a second end of the eighth capacitor is connected with the negative output end of the second amplifier, a first end of the fifth resistor is connected with the first end of the third feedback resistor, and a second end of the fifth resistor is connected with the negative output end of the second amplifier; a first end of the ninth capacitor is connected with the second end of the fourth feedback resistor, a second end of the ninth capacitor is connected with the positive output end of the second amplifier, a first end of the sixth resistor is connected with the first end of the fourth feedback resistor, and a second end of the sixth resistor is connected with the positive output end of the second amplifier. The first signal processing unit further comprises a sample-and-hold module; 18. The press detection apparatus according to claim 17, characterized by, The sample-and-hold module comprises an eighth switch, a ninth switch, a tenth switch, an eleventh switch, a tenth capacitor and an eleventh capacitor; a first end of the eighth switch is connected with the first output end of the filter unit, a second end of the eighth switch is connected with a first end of the tenth capacitor and a first end of the ninth switch, a second end of the ninth switch is connected with a first input end of the analog-to-digital converter, and a second end of the tenth capacitor is grounded; a first end of the tenth switch is connected with the second output end of the filter unit, a second end of the tenth switch is connected with a first end of the eleventh capacitor and a first end of the eleventh switch, a second end of the eleventh switch is connected with a second input end of the analog-to-digital converter, and a second end of the eleventh capacitor is grounded; The sample-and-hold module is used for holding the identification voltage. The first signal processing unit further comprises a buffer amplifier; 19. The press detection apparatus according to claim 18, characterized by a first input end of the buffer amplifier is connected with the second end of the ninth switch, a second input end of the buffer amplifier is connected with the second end of the eleventh switch, a first output end of the buffer amplifier is connected with the first input end of the analog-to-digital converter, and a second output end of the buffer amplifier is connected with the second input end of the analog-to-digital converter; The buffer amplifier is used for performing signal amplification processing on the identification voltage. The demodulation circuit comprises a first demodulation branch and a second demodulation branch; 20. The press detection apparatus according to any one of claims 1 to 19, characterized by ​ The first demodulation branch is configured to perform sinusoidal demodulation on the detection signal to obtain a first identification sub-signal, and the second demodulation branch is configured to perform cosine demodulation on the detection signal to obtain a second identification sub-signal. The demodulation circuit is configured to generate the identification signal according to the first identification sub-signal and the second identification sub-signal.

21. A touch chip, comprising: The touch chip is electrically connected with the pressure sensor and the electrode in the electronic device; The touch chip is configured to generate a detection signal according to a pressing signal generated by the pressure sensor when a pressing surface of the electronic device is pressed, and send the detection signal to the demodulation circuit, so that the demodulation circuit performs demodulation processing on the detection signal to obtain an identification signal, and the processing unit identifies the pressing operation according to the identification signal.

22. An electronic device, comprising: The electronic device comprises an electrode, a processing unit and the pressing detection device according to any one of claims 1-20. The electrode is electrically connected with the touch chip in the pressing detection device, and the processing unit is electrically connected with the pressing detection device. The processing unit is configured to identify the pressing operation according to the identification signal sent by the pressing detection device.

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