CN110554814B

CN110554814B - Touch sensing device and method for electromagnetic handwriting board

Info

Publication number: CN110554814B
Application number: CN201910893006.9A
Authority: CN
Inventors: 万力锋
Original assignee: Shenzhen Unipen Touch Technology Co ltd
Current assignee: Shenzhen Unipen Touch Technology Co ltd
Priority date: 2019-09-20
Filing date: 2019-09-20
Publication date: 2024-07-05
Anticipated expiration: 2039-09-20
Also published as: CN110554814A

Abstract

A touch sensing device and method for electromagnetic handwriting board, which transmits carrier signal and receives modulation signal fed back by electromagnetic pen through receiving-transmitting coil in carrier module; the processing module processes the modulated signal and restores the touch signal; the gating module comprises a plurality of X-axis coordinate coils and a plurality of Y-axis coordinate coils which are respectively used for receiving and outputting X-axis coordinate signals and Y-axis coordinate signals fed back by the electromagnetic pen; the main control module is used for calibrating the X-axis coordinate coil corresponding to the maximum value of the received X-axis coordinate signal and the Y-axis coordinate coil corresponding to the maximum value of the received Y-axis coordinate signal so as to determine the touch position of the electromagnetic pen on the display panel, and is also used for uploading the information of the touch signal and the touch position. According to the touch sensing device and the touch sensing method, the functions of transmitting the carrier signal and sampling the coordinate signal are realized by different coils, one coil does not need to be multiplexed in a time-sharing way, and the touch sensing device and the touch sensing method are high in signal processing efficiency, strong in instantaneity and low in difficulty.

Description

Touch sensing device and method for electromagnetic handwriting board

Technical Field

The invention belongs to the technical field of electromagnetic handwriting input, and particularly relates to a touch sensing device and method for an electromagnetic handwriting board.

Background

At present, a traditional electromagnetic handwriting screen adopts a single antenna to perform time-sharing multiplexing, so that time-sharing signal receiving and transmitting are realized. However, the mode of time-sharing receiving and transmitting signals needs to be switched repeatedly, the efficiency of the system on signal processing is low, the signal processing difficulty is high, and the electromagnetic pen can only be charged and stored intermittently, so that the power supply cannot supply power stably, the stability of signals in the system is affected, and the reliability of the electromagnetic handwriting screen is reduced.

Therefore, the traditional magnetic handwriting screen technical scheme has the problems of low efficiency and low reliability of signal processing caused by repeated mode switching by adopting a mode of time-sharing signal receiving and transmitting.

Disclosure of Invention

In view of the above, the embodiment of the invention provides a touch sensing device and a method for an electromagnetic handwriting board, which aim to solve the problems of low efficiency, high difficulty in signal processing and low reliability of signal processing caused by repeated mode switching in a mode of time-sharing signal receiving and transmitting adopted in the traditional technical scheme.

A first aspect of an embodiment of the present invention provides a touch sensing device for an electromagnetic handwriting board, where the electromagnetic handwriting board includes a display panel, and the display panel is used as an operation platform of an electromagnetic pen, and the touch sensing device includes:

The carrier module comprises a receiving and transmitting coil, and is used for converting a received excitation signal into a carrier signal, transmitting the carrier signal through the receiving and transmitting coil, and receiving a modulated signal backscattered by the electromagnetic pen through the receiving and transmitting coil, wherein the modulated signal is a touch signal modulated on the carrier signal by the electromagnetic pen;

The processing module is connected with the carrier module and is used for restoring and outputting the touch control signal after performing signal processing on the modulation signal;

The gating module comprises a plurality of positioning coils, wherein the plurality of positioning coils comprise a plurality of X-axis coordinate coils and a plurality of Y-axis coordinate coils, and the gating module sequentially gates the plurality of positioning coils according to gating signals in a preset sequence so as to receive and output a plurality of X-axis coordinate signals and a plurality of Y-axis coordinate signals fed back by the electromagnetic pen; and

The main control module is connected with the carrier module, the processing module and the gating module, and is used for outputting the excitation signal and the gating signal, receiving the touch control signal, a plurality of X-axis coordinate signals and a plurality of Y-axis coordinate signals, calibrating the X-axis coordinate coil corresponding to the maximum value of the received X-axis coordinate signals and the Y-axis coordinate coil corresponding to the maximum value of the received Y-axis coordinate signals, determining the touch control position of the electromagnetic pen on the display panel, and uploading the information of the touch control signal and the touch control position.

The second aspect of the embodiment of the invention provides a touch sensing method for an electromagnetic handwriting board, wherein the electromagnetic handwriting board comprises a display panel, the display panel is used as an operation platform of an electromagnetic pen, and a main control module is adopted for touch sensing to generate and output an excitation signal and a gating signal;

The main control module is adopted to generate and output an excitation signal and a gating signal;

After the excitation signal is converted into a carrier signal by adopting a carrier module, the carrier signal is transmitted through a receiving and transmitting coil, and the receiving and transmitting coil receives a modulated signal backscattered by the electromagnetic pen, wherein the modulated signal is a touch signal modulated on the carrier signal by the electromagnetic pen;

a processing module is adopted to process the modulated signal, and then the modulated signal is restored and the touch signal is output;

A gating module is adopted to successively gate a plurality of positioning coils according to the gating signals in a preset sequence so as to receive and output a plurality of X-axis coordinate signals and a plurality of Y-axis coordinate signals fed back by the electromagnetic pen; the plurality of positioning coils comprise a plurality of X-axis coordinate coils and a plurality of Y-axis coordinate coils;

And the main control module is used for receiving the touch control signals, the X-axis coordinate signals and the Y-axis coordinate signals, calibrating the X-axis coordinate coil corresponding to the maximum value of the received X-axis coordinate signals and the Y-axis coordinate coil corresponding to the maximum value of the received Y-axis coordinate signals so as to determine the touch control position of the electromagnetic pen, and uploading the information of the touch control signals and the touch control position.

According to the touch sensing device and method for the electromagnetic handwriting board, the functions of transmitting the carrier signal and sampling the coordinate signal are realized by different coils, namely, the transmitting and receiving coil transmits the carrier signal and receives the modulation signal fed back by the electromagnetic pen, and the positioning coil collects the X-axis coordinate signal and the Y-axis coordinate signal, so that one coil does not need to be multiplexed in a time-sharing way, the receiving and the modulating signal and the receiving coordinate signal can be simultaneously carried out, the signal processing efficiency is high, and the instantaneity is strong; the receiving and transmitting coil and the positioning coil are connected with different loops, the different loops respectively process the modulation signal and the carrier signal, and the signal processing difficulty is low; the electromagnetic pen can continuously receive the carrier signal and charge and store energy, so that the stability and reliability of the electromagnetic pen in operation are improved, and the service life of the battery is prolonged.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic block diagram of a touch sensing device for an electromagnetic handwriting board according to a first aspect of the present invention;

FIG. 2 is a schematic diagram of wiring of a transceiver coil and a positioning coil in the touch sensing device shown in FIG. 1;

FIG. 3 is a schematic diagram of a unit structure of the touch sensing device shown in FIG. 1;

FIG. 4 is a schematic circuit diagram of an example of a carrier module in the touch sensing device shown in FIG. 3;

FIG. 5 is a schematic circuit diagram of an example of a processing module in the touch sensing device shown in FIG. 3;

FIG. 6 is a schematic circuit diagram of an example of a coordinate signal processing unit in the touch sensing device shown in FIG. 3;

FIG. 7 is a schematic circuit diagram of an example of a switch unit in the touch sensing device shown in FIG. 3;

fig. 8 is a specific flowchart of a touch sensing method for an electromagnetic handwriting board according to a second aspect of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

Referring to fig. 1, a schematic block diagram of a touch sensing device for an electromagnetic handwriting board according to a first aspect of the present invention is shown, for convenience of explanation, only the portions related to the embodiment are shown, and the details are as follows:

a touch sensing device for an electromagnetic handwriting board comprises a carrier module 20, a processing module 30, a gating module 40 and a main control module 10. The electromagnetic handwriting board includes a display panel 100, and the display panel 100 serves as an operation platform of the electromagnetic pen 200.

The carrier module 20 includes a transceiver coil 2011, the carrier module 20 converts the received excitation signal mod_pwm into a carrier signal, and transmits the carrier signal through the transceiver coil 2011, and the transceiver coil 2011 receives a modulated signal FM backscattered by the electromagnetic pen 200, where the modulated signal FM is a touch signal modulated on the carrier signal by the electromagnetic pen.

Specifically, the transceiver coil 2011 may be implemented by a single set of coils, or may be implemented by multiple sets of coils. The excitation signal MOD_PWM is a pulse width adjustable signal output by the main control module 10, and the main control module 10 is realized by adopting a 32-bit high-speed high-performance ARM single chip microcomputer as an excitation source. After push-pull amplification treatment is carried out on the excitation signal MOD_PWM by the carrier module 20, the excitation signal MOD_PWM resonates by an inductance-capacitance series resonant circuit, and an alternating electromagnetic field appears in space, namely a carrier signal is generated and radiated to space; the carrier signal is a sine wave signal. The electromagnetic pen 200 in the coverage area of the carrier signal is triggered after sensing the alternating electromagnetic field in the space, charges and stores energy, and modulates the touch signal of the electromagnetic pen into the carrier signal, and then outwards backscatters the modulated signal FM through the backscattering principle.

Because the transceiver coil 2011 is only used for continuously transmitting carrier signals, the electromagnetic pen 200 can continuously perform wireless charging and energy storage, and the defect of insufficient charging caused by intermittent transmission of carrier signals is avoided, so that the reliability and the stability of the electromagnetic pen 200 in the working process are greatly improved.

The transceiver coil 2011 is only used for continuously transmitting the carrier SIGNAL and receiving the modulation SIGNAL FM, but not used for receiving the coordinate SIGNAL PEN_SIGNAL, so that the carrier SIGNAL can be continuously transmitted, the SIGNAL processing efficiency is high, the instantaneity is strong, and the SIGNAL processing difficulty is low; the electromagnetic pen 200 in the coverage range of the carrier signal can continuously receive the carrier signal to charge and store energy, so that the reliability of the electromagnetic pen 200 in the working process is greatly improved, and the defect of insufficient charging caused by too short carrier signal receiving time is avoided, thereby influencing the modulation process and the emission process of the touch signal.

The positioning accuracy of the touch position of the electromagnetic PEN 200 is high, the real-time performance is high, the problem of delayed receiving of the coordinate SIGNAL PEN_SIGNAL is solved, and the user experience is improved.

The processing module 30 is connected to the carrier module 20, and the processing module 30 is configured to perform signal processing on the modulated signal FM and output a touch signal.

Specifically, after demodulating, filtering and waveform shaping the modulated signal FM, the processing module 30 restores the touch signal modulated on the carrier signal, and transmits the touch signal to the main control module 10, and the main control module 10 further demodulates the touch signal.

Optionally, the touch signal includes pressure information and/or key information of the electromagnetic pen 200. Specifically, the display panel 100 of the electromagnetic handwriting board is used as an operation platform of the electromagnetic pen 200, so that a user holds the electromagnetic pen 200 to operate thereon, man-machine interaction keys are displayed on the display panel 100, and the user touches the corresponding man-machine interaction keys by using the electromagnetic pen 200 according to actual needs, so that the electromagnetic pen 200 generates a touch signal containing key information. In addition, the display panel 100 may also be used as a handwriting input platform, and the user holds the electromagnetic pen 200 to write or draw thereon, so that the touch signal generated by the electromagnetic pen 200 includes pressure-sensitive information. The touch signal may include both pressure information and key information, or may include only pressure information.

The gating module 40 includes a plurality of positioning coils 401, the plurality of positioning coils 401 includes a plurality of X-axis coordinate coils and a plurality of Y-axis coordinate coils, and the gating module 40 sequentially performs gating processing on the plurality of positioning coils 401 according to a gating signal in a preset sequence, so as to receive and output a plurality of X-axis coordinate signals and a plurality of Y-axis coordinate signals fed back by the electromagnetic pen 200.

Specifically, the main control module 10 outputs a gating signal to the gating module 40, and controls the gating module 40 to gate the positioning coils 401 one by one, so that the preset gating sequence of the positioning coils 401 does not affect the working efficiency of the whole touch sensing device. The plurality of positioning coils 401 includes a plurality of X-axis coordinate coils and a plurality of Y-axis coordinate coils, and the plurality of positioning coils 401 are configured to receive the plurality of X-axis coordinate signals and the plurality of Y-axis coordinate signals fed back by the electromagnetic pen 200.

The plurality of X-axis coordinate coils includes an X1-axis coordinate coil, an X2-axis coordinate coil … … Xn-1-axis coordinate coil, and an Xn-axis coordinate coil; the plurality of Y-axis coordinate coils includes a Y1-axis coordinate coil, a Y2-axis coordinate coil … … Ym-1-axis coordinate coil, and a Ym-axis coordinate coil.

For example, in analysis, assuming that the electromagnetic pen 200 touches a (X15, Y20) point of the display panel 100 at a certain moment, after the gating module 40 gates all the positioning coils 401 one by one, the value of the X-axis coordinate signal received by the X15-axis coordinate coil is the largest among the X-axis coordinate signals received by the X15-axis coordinate coils, and the value of the Y-axis coordinate signal received by the Y20-axis coordinate coil is the largest among the Y-axis coordinate signals received by the Y-axis coordinate coils, so that after one round of gating is performed on all the positioning coils 401, it can be initially determined that the touch position of the electromagnetic pen 200 on the display panel 100 at the moment is the (X15, Y20) point.

In order to precisely acquire the touch position information of the electromagnetic pen 200, errors are minimized, after initially determining that the touch position of the electromagnetic pen on the display panel is a (X15, Y20) point at this time, the gating module 40 again gates the X-axis coordinate coils X13, X14, X15, X16, X17 and the Y-axis coordinate coils Y18, Y19, Y20, Y21, Y22, that is, again scans the coil X15 and the plurality of X-axis coordinate coils adjacent to the coil X15, and again scans the coil Y20 and the plurality of Y-axis coordinate coils adjacent to the coil Y20, precisely calculates and recalibrates the touch position point of the electromagnetic pen on the display panel through a software algorithm.

Because the positioning coil 401 is only used for receiving the coordinate SIGNAL pen_signal, and is not multiplexed to transmit the carrier SIGNAL or receive the modulation SIGNAL FM, the real-time performance of receiving the coordinate SIGNAL pen_signal is greatly improved, the positioning accuracy of the touch position of the electromagnetic PEN 200 is high, the problem of delayed receiving of the coordinate SIGNAL pen_signal is solved, and the user experience is improved. The positioning coil is not multiplexed any more to be used as a receiving and transmitting coil and is only used for receiving the coordinate SIGNAL PEN_SIGNAL, the SIGNAL processing difficulty is small, and the SIGNAL processing efficiency is improved by nearly one time. The coordinate SIGNAL pen_signal is a generic term for both an X-axis coordinate SIGNAL and a Y-axis coordinate SIGNAL throughout.

The main control module 10 is configured to output an excitation signal mod_pwm and a strobe signal, receive a touch signal, a plurality of X-axis coordinate signals, and a plurality of Y-axis coordinate signals, and calibrate an X-axis coordinate coil corresponding to a maximum value of the received X-axis coordinate signals and a Y-axis coordinate coil corresponding to a maximum value of the received Y-axis coordinate signals to determine a touch position of the electromagnetic pen 200 on the display panel 100, and the main control module 10 is further configured to upload information of the touch signal and the touch position. The information of the touch position is contained in the X-axis coordinate signal and the Y-axis coordinate signal.

Specifically, the main control module 10 uploads the coordinate information of the touch signal and the touch position to the upper computer of the electromagnetic handwriting board, and the upper computer displays the sliding track of the electromagnetic pen 200 and the key function menu on the electromagnetic handwriting board in real time, so as to highly restore and present the original handwriting. The main control module 10 communicates with the upper computer through a USB interface, an I2C interface or a UART interface of the main control module, and uploads the touch signal and the information of the touch position to the upper computer.

Referring to fig. 2, a schematic diagram of wiring of the transceiver coil and the positioning coil in the touch sensing device shown in fig. 1 is shown, for convenience of explanation, only the portions related to the present embodiment are shown, and the details are as follows:

Optionally, the transceiver coil 2011 and the positioning coil 401 are distributed on the PCB board. The transceiver coil 2011 is annularly arranged at the edge of the PCB, and the plane of the PCB is parallel to the plane of the display panel 100. The plane of the positioning coils 401 is parallel to the plane of the display panel 100, wherein the X-axis coordinate coils are perpendicular to the Y-axis coordinate coils; the X-axis coordinate coil and the Y-axis coordinate coil are respectively referenced to each other. The PCB is used as a carrier for bearing each module in the touch sensing device, and the touch sensing device is arranged in the electromagnetic handwriting board.

The transceiver coil 2011 and the plurality of positioning coils 401 together form an antenna board, which is wired on a PCB board.

As shown in fig. 2, one ends of the plurality of positioning coils 401 are commonly connected, and the other ends of the plurality of positioning coils 401 are connected to the gating module 40, specifically, to the switching unit 402 of the gating module 40, and the gated positioning coils 401 receive the coordinate SIGNAL pen_signal and transmit through the corresponding switching unit 402. The transceiver coil 2011 is connected to the processing module 30 and the carrier module 20.

Referring to fig. 3, a schematic unit structure of the touch sensing device shown in fig. 1 is shown, for convenience of explanation, only the portions related to the present embodiment are shown in detail as follows:

in an alternative embodiment, the carrier module 20 includes a push-pull unit 202 and a resonance unit 201.

The push-pull unit 202 is connected to the main control module 10, and the push-pull unit 202 is configured to amplify the excitation signal mod_pwm and output the amplified excitation signal mod_pwm to the resonance unit 201.

The resonance unit 201 is connected to the push-pull unit 202, the resonance unit 201 includes a transmitting-receiving coil 2011 and a capacitor connected in series with the transmitting-receiving coil 2011, and the resonance unit 201 is configured to convert the amplified excitation signal mod_pwm into a carrier signal and transmit the carrier signal.

Specifically, the transceiver coil 2011 and a capacitor connected in series with the transceiver coil form an inductance-capacitance series resonance circuit, and the inductance-capacitance series resonance circuit resonates to generate a sine wave signal, so that an alternating electromagnetic field appears in a space, and the sine wave signal is a carrier signal.

In an alternative embodiment, the processing module 30 includes a demodulation unit 301, a filtering unit 302, and a shaping unit 303.

The demodulation unit 301 is connected to the transceiver coil 2011 in the carrier module 20, the filtering unit 302 is connected to the demodulation unit 301, the shaping unit 303 is connected to the filtering unit 302, and the shaping unit 303 is further connected to the main control module 10.

The demodulation unit 301 is configured to demodulate the modulated signal FM and output a demodulated signal.

Specifically, the transceiver coil 2011 outputs the received modulated signal FM to the demodulation unit 301, and the demodulation unit 301 demodulates the received modulated signal FM and outputs a demodulated signal to the filter unit 302.

The filtering unit 302 is configured to filter the demodulation signal and output a demodulation filtered signal. Specifically, the filtering unit 302 filters out the dc interference signal in the demodulated signal.

The shaping unit 303 is configured to output the touch signal to the main control module 10 after performing waveform shaping on the demodulated and filtered signal. Specifically, the touch signal includes pressure sensing information and/or key information.

In an alternative embodiment, the gating module 40 includes a plurality of positioning coils 401, a coordinate signal processing unit 403, and a plurality of switching units 402.

The coordinate signal processing unit 403 is connected to the main control module 10, and each switch unit 402 is respectively connected between the coordinate signal processing unit 403 and the positioning coils 401 of a preset number in series.

The plurality of switching units 402 are configured to gate the analog switches inside corresponding to the gate SIGNALs to operate the corresponding positioning coils 401, and the plurality of switching units 402 are also configured to output the plurality of X-axis coordinate SIGNALs and the plurality of Y-axis coordinate SIGNALs to the coordinate SIGNAL pen_signal unit.

Specifically, each switch unit 402 includes eight analog switches, and each analog switch is correspondingly connected in series between the non-ground terminal of one positioning coil 401 and the input terminal of the coordinate signal processing unit 403. Each switch unit 402 correspondingly gates an internal analog switch according to a gate SIGNAL output by the main control module 10, and the gated analog switch communicates the positioning coil 401 connected with the switch unit with the coordinate SIGNAL processing unit 403, so that the positioning coil 401 receives the coordinate SIGNAL pen_signal and transmits the coordinate SIGNAL pen_signal to the coordinate SIGNAL processing unit 403, and the coordinate SIGNAL processing unit 403 processes the coordinate SIGNAL pen_signal.

The coordinate signal processing unit 403 is configured to perform filtering processing, multistage amplification processing, and integration processing on the plurality of X-axis coordinate signals and the plurality of Y-axis coordinate signals, and output the signals to the main control module 10.

Specifically, after receiving the X-axis coordinate signal or the Y-axis coordinate signal, the main control module 10 obtains the voltage value of the X-axis coordinate signal or the Y-axis coordinate signal by applying a corresponding program, and processes the plurality of voltage values by using an bubbling program to obtain the maximum value of the plurality of X-axis coordinate signals and the maximum value of the plurality of Y-axis coordinate signals, wherein the maximum value is the maximum value of the voltage values.

The main control module 10 determines the touch position of the electromagnetic pen 200 on the display panel 100 by obtaining and calibrating the maximum values of the plurality of X-axis coordinate signals and the maximum values of the plurality of Y-axis coordinate signals.

Referring to fig. 4, an exemplary schematic circuit diagram of the carrier module 20 in the touch sensing device shown in fig. 3 is shown, for convenience of explanation, only the portions related to the present embodiment are shown in detail as follows:

The carrier module 20 includes a push-pull unit 202 and a resonance unit 201.

The push-pull unit 202 includes a capacitor C5, a capacitor C8, a capacitor C9, a capacitor C10, a resistor R1, a resistor R4, a resistor R5, a resistor R6, a resistor R15, a resistor R22, a resistor R64, a diode D1, a diode D3, an NPN transistor Q1, an NPN transistor Q3, and a PNP transistor Q2.

The resonance unit 201 includes a transmitting/receiving coil 2011, a capacitor C8, a capacitor C9, and a capacitor C10.

The first end of the capacitor C5 is connected to the main control module 10, so as to receive an excitation signal mod_pwm output by the main control module 10, where the excitation signal mod_pwm is a pulse width adjustable signal.

The second end of the capacitor C5, the first end of the resistor R1, the first end of the resistor R6 and the first end of the resistor R22 are commonly connected, the second end of the resistor R1 is connected with a 5V power supply, the second end of the resistor R6 is grounded, the second end of the resistor R22 is connected with the base electrode of the NPN triode Q3, and the emitter electrode of the NPN triode Q3 is grounded.

The first end of the resistor R15 is connected with the collector of the NPN triode Q1, the second end of the resistor R15, the anode of the diode D1 and the base of the NPN triode Q1 are connected together, the cathode of the diode D1 is connected with the anode of the diode D3, the cathode of the diode D3 is connected with the collector of the NPN triode Q3, and the emitter of the NPN triode Q1 is connected with the first end of the resistor R4.

The second end of the resistor R4, the second end of the resistor R5 and the first end of the resistor R64 are commonly connected, the second end of the resistor R5 is connected with the emitter of the PNP triode Q2, the collector of the PNP triode Q2 is grounded, and the base of the PNP triode Q2 is connected with the cathode of the diode D3.

The second end of the resistor R64 is connected to the first end of the positioning coil 401, and the second end of the positioning coil 401, the first end of the capacitor C8, the first end of the capacitor C9, and the first end of the capacitor C10 are commonly connected to each other, and the second end of the capacitor C8, the second end of the capacitor C9, and the second end of the capacitor C10 are grounded.

The NPN triode Q1 and the PNP triode Q2 form a push-pull circuit together, the emitters of the NPN triode Q1 and the PNP triode Q2 are respectively connected together through a resistor R4 and a resistor R5, and the common junction is used as an output end of the push-pull circuit. The excitation signal mod_pwm is amplified by the push-pull circuit and then output to the resonance unit 201. The resonance unit 201 is equivalent to an inductance-capacitance series resonance circuit, and is composed of a positioning coil 401, a capacitor C8, a capacitor C9 and a capacitor C10, and an excitation signal MOD_PWM output after push-pull amplification generates resonance through the resonance unit 201, so that a sine wave signal is generated, an alternating electromagnetic field appears in the space, the sine wave signal is a carrier signal, and the electromagnetic pen 200 in the coverage range of the carrier signal is triggered after receiving the carrier signal, charges and stores energy and feeds back a modulation signal FM.

Referring to fig. 5, a schematic circuit diagram of the processing module 30 in the touch sensing device shown in fig. 3 is shown, for convenience of explanation, only the portions related to the present embodiment are shown in detail as follows:

the processing module 30 comprises a demodulation unit 301, a filtering unit 302 and a shaping unit 303.

The demodulation unit 301 includes a diode D2, a capacitor C6, and a resistor R7.

The filtering unit 302 includes a capacitor C7.

The shaping unit 303 includes a capacitor C14, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a comparator U5-A, a comparator U5-B, and an NPN triode Q4.

The anode of the diode D2 is connected to the second end of the transceiver coil 2011 to receive the modulation signal FM sensed by the transceiver coil 2011, and the cathode of the diode D2, the first end of the capacitor C6 and the first end of the resistor R7 are commonly connected, and the second end of the capacitor C6 and the second end of the resistor R7 are grounded.

The first end of the resistor R7 is connected with the first end of the capacitor C7, the second end of the capacitor C7 is connected with the first end of the resistor R8, the second end of the resistor R8, the first end of the capacitor C14, the first end of the resistor R9 and the inverting input end of the comparator U5-A are commonly connected, the second end of the resistor R9 and the first end of the resistor R12 are commonly connected with the output end of the comparator U5-A, the second end of the resistor C14 is grounded, the second end of the resistor R12 is connected with the base electrode of the NPN transistor Q4, the first end of the resistor R13 is connected with a 5V power supply, the second end of the resistor R13, the collector electrode of the NPN transistor Q4 and the first end of the resistor R14, namely the inverting input end of the comparator, are commonly connected, and the emitter electrode of the NPN transistor Q4 is grounded.

The second end of the resistor R14 is connected with the output end of the comparator, the positive input end of the comparator U5-A, the positive input end of the comparator U5-B, the first end of the resistor R11 and the first end of the resistor R10 are commonly connected, the second end of the resistor R11 is grounded, and the second end of the resistor R10 is connected with a 5V power supply.

The capacitor C7 is used for filtering the dc interference signal. The output end of the comparator U5-B is connected with the main control module 10 and is used for outputting a restored touch signal after demodulation, filtering and shaping and conditioning of the modulated signal FM, and the restored touch signal is transmitted to the main control module 10 in the form of a DATA stream DATA.

Referring to fig. 6, a schematic circuit diagram of an example of the coordinate signal processing unit 403 in the touch sensing device shown in fig. 3 is shown, for convenience of explanation, only the portions related to the present embodiment are shown, and the details are as follows:

The gating module 40 includes a coordinate signal processing unit 403 and a plurality of switching units 402.

The coordinate signal processing unit 403 includes a resistor R28, a resistor R29, a resistor R30, a resistor R31, a resistor R32, a resistor R33, a resistor R26, a resistor R27, a resistor R24, a resistor R25, a resistor 23, a resistor R34, a resistor R35, a resistor R36, a resistor R37, a resistor R38, a resistor R39, a resistor R40, a resistor R41, a resistor R42, a resistor R43, a resistor R44, a resistor R45, a resistor R46, a resistor R47, a resistor R48, a resistor R50, a capacitor C43, a capacitor C44, a capacitor C42, a capacitor C41, a capacitor C45, a capacitor C46, a capacitor C47, a capacitor C48, a capacitor C49, a capacitor C4, an amplifier U16-a, an amplifier U16-B, an amplifier U16-C, an amplifier U16-D, an amplifier U17-a, an amplifier U17B, an amplifier U17-C, an amplifier U17-D, N, a diode D6, a diode D7, a diode D9, a diode D10, and a diode Q11.

The first end of the capacitor C43 is connected to the switching unit 402 to receive the coordinate SIGNAL PEN_SIGNAL, the second end of the capacitor C43, the first end of the resistor R29 and the non-inverting input end of the amplifier U16-A are commonly connected, and the inverting input end of the amplifier U16-A, the first end of the resistor R28 and the first end of the R resistor 30 are commonly connected; the second end of the resistor R30, the first end of the resistor R30, i.e., the output end of the amplifier U16-A, are commonly connected, the second end of the resistor R31, the first end of the capacitor C44 and the non-inverting input end of the amplifier U16-D are commonly connected, and the inverting input end of the amplifier U16-D, the first end of the resistor R32 and the first end of the resistor R33 are commonly connected.

The second end of the resistor R33, the output end of the amplifier U16-D and the non-inverting input end of the amplifier U16-C are commonly connected, the inverting input end of the amplifier U16-C, the first end of the resistor R26 and the first end of the resistor R27 are commonly connected, the second end of the resistor R27, the output end of the amplifier U16-C and the first end of the capacitor C42 are commonly connected, and the second end of the capacitor C42, the first end of the resistor R23 and the non-inverting input end of the amplifier U16-B are commonly connected; the inverting input of amplifier U16-B, the first terminal of resistor R24, and the first terminal of resistor R25 are commonly connected, and the second terminal of resistor R25, the output of amplifier U16-B, and the first terminal of capacitor C41 are commonly connected.

The second end of the capacitor C41 is commonly connected with the first end of the resistor R35, the second end of the resistor R35, the drain electrode of the N-channel field effect transistor Q5 and the first end of the resistor 34 are commonly connected, the grid electrode of the N-channel field effect transistor Q5, the first end of the resistor R46 and the anode of the diode D11 are commonly connected, the cathode of the diode D11 is connected with the anode of the diode D6, the cathode of the diode D6 is connected with the anode of the diode D9, the cathode of the diode D9 is connected with the anode of the diode D7, the cathode of the diode D7 is connected with the first end of the resistor R45, and the first end of the resistor R45 is commonly connected with the source electrode of the N-channel field effect transistor Q5; the second end of the resistor R46 is connected with the main control module 10.

The second terminal of resistor R34, the first terminal of resistor R36 and the inverting input terminal of amplifier U17-A are commonly connected, and the non-inverting input terminal of amplifier U17-A is commonly connected with the first terminal of resistor R50. The output end of the amplifier U17-A, the second end of the resistor R36 and the first end of the resistor R37 are commonly connected, the second end of the resistor R37, the first end of the resistor R38 and the first end of the capacitor C45 are commonly connected, and the second end of the resistor R38, the first end of the capacitor C48 and the non-inverting input end of the amplifier U17-B are commonly connected; the inverting input of the amplifier U17-B, the first terminal of the resistor R39 and the first terminal of the resistor R40 are commonly connected, the second terminal of the resistor R40, the second terminal of the output capacitor C45 of the amplifier U17-B and the first terminal of the capacitor C46 are commonly connected, the second terminal of the capacitor C46, the first terminal of the resistor R41 and the first terminal of the capacitor C47 are commonly connected, and the second terminal of the capacitor C47, the first terminal of the resistor R42 and the non-inverting input of the amplifier U17-C are commonly connected.

The inverting input terminal of the amplifier U17-C, the first terminal of the resistor R43 and the first terminal of the resistor R44 are commonly connected, and the second terminal of the resistor R44, the output terminal of the amplifier U17-C, the second terminal of the resistor R41 and the first terminal of the resistor R47 are commonly connected; the second end of the resistor R47 is commonly connected with the anode of the diode D10, and the cathode of the diode D10, the non-inverting input end of the amplifier U17-D, the first end of the capacitor C49 and the collector of the NPN triode Q6 are commonly connected; the second end of the capacitor C49 is connected with the emitter of the NPN triode Q6, and the base electrode of the NPN triode Q6 is connected with the main control module 10. The inverting input terminal of the amplifier U17-D and the first terminal of the resistor R48, namely the first terminal of the resistor R49 are commonly connected; the second end of the resistor R48, the output end of the amplifier U17-D and the first end of the capacitor C4 are commonly connected, and the output end of the amplifier U17-D is connected with the main control module 10.

The second end of resistor R28, the second end of resistor R29, the second end of resistor R30, the second end of capacitor C44, the second end of resistor R26, the second end of resistor R24, the second end of resistor R23, the second end of resistor R45, the second end of resistor R39, the second end of resistor R50, the second end of capacitor C48, the second end of resistor R43, the second end of resistor R42, the second end of capacitor C4, and the second end of capacitor C49 are connected to analog ground.

Specifically, the first terminal of the capacitor C43 is used as an input terminal of the coordinate SIGNAL processing unit 403, and is connected to the switching unit 402, for receiving the coordinate SIGNAL pen_signal. After the input coordinate SIGNAL pen_signal is subjected to multistage operational amplification processing, filtering processing and integration processing by the circuit of the coordinate SIGNAL processing unit 403, the optimized coordinate SIGNAL is output to an analog-to-digital conversion interface of the main control module 10, namely a pos_ad port, and the voltage value of the coordinate SIGNAL pen_signal is obtained and compared by the main control module 10 to calibrate an X-axis coordinate coil corresponding to the maximum value of the X-axis coordinate SIGNAL and a Y-axis coordinate coil corresponding to the maximum value of the Y-axis coordinate SIGNAL.

The main control module 10 is further configured to output a GAIN control SIGNAL gain_ctrl to calibrate the GAIN of the coordinate SIGNAL pen_signal received by the positioning coil 401; the main control module 10 is further configured to output an integrate capacitor emptying SIGNAL dic h for emptying the integrate capacitor, and the coordinate SIGNAL processing unit 403 empties the integrate capacitor in the circuit before sampling the next coordinate SIGNAL pen_signal every time the coordinate SIGNAL pen_signal is sampled.

Referring to fig. 7, a schematic circuit diagram of the switch unit 402 in the touch sensing device shown in fig. 3 is shown, for convenience of explanation, only the portions related to the present embodiment are shown in detail as follows:

The gating module 40 includes a coordinate signal processing unit 403 and a plurality of switch units 402, where each switch unit 402 includes eight analog switches, and each analog switch is correspondingly connected in series between a non-grounded end of one positioning coil 401 and an input end of the coordinate signal processing unit 403. Each switch unit 402 correspondingly gates an internal analog switch according to a gate SIGNAL output by the main control module 10, and the gated analog switch communicates the positioning coil 401 connected with the switch unit with the coordinate SIGNAL processing unit 403, so that the positioning coil 401 receives the coordinate SIGNAL pen_signal and transmits the coordinate SIGNAL pen_signal to the coordinate SIGNAL processing unit 403, and the coordinate SIGNAL processing unit 403 processes the coordinate SIGNAL pen_signal.

Optionally, each switching unit 402 is implemented by using an 8-to-1 data selector, where each 8-to-1 data selector includes 8 analog switches therein, and gates the corresponding analog switches according to the received 4-way gate signals (INH, C, B, a).

The 4-way strobe signals are binary codes, and if and only if strobe signal INH is 0, one of the 8 analog switches will be closed. Taking 4 paths of gating signals (INH, C, B and A) as examples, wherein the gating signals are (0, 1,0 and 0) respectively, the analog switch closed at the moment is the 5 th analog switch, namely the analog switch with the number of 04, and all the other 7 analog switches are not closed; assuming that the analog switch of number 04 is connected in series between the coordinate SIGNAL processing unit 403 and the Y3-axis coordinate coil, the Y3-axis coordinate coil receives the Y3-axis coordinate SIGNAL pen_signal and transmits the Y3-axis coordinate SIGNAL pen_signal to the coordinate SIGNAL processing unit 403 through the closed analog switch of number 04, which is subjected to filtering, multistage op-amp, and integration processing by the coordinate SIGNAL processing unit 403.

The main control module 10 outputs 4 paths of gate signals to the switching unit 402,4 paths of gate signals INH, a, B and C and 8 analog switches 00, 01, 02, 03, 04, 05, 06 and 07 according to the following table 1:

TABLE 1

The following specifically describes the working principle of the touch sensing device:

The main control module 10 is powered on to complete the initialization of the program. As an excitation source, the main control module 10 outputs an excitation signal mod_pwm, which is specifically a low-frequency PWM square wave signal. After push-pull amplification, the excitation signal mod_pwm drives an inductor-capacitor series resonant circuit, and a low-frequency carrier signal is emitted through the transceiver coil 2011 to spatially generate an alternating electromagnetic field. The electromagnetic pen 200 within the coverage range of the alternating electromagnetic field stores energy through electromagnetic resonance, charges stably and uninterruptedly, and enters a working state.

Meanwhile, the electromagnetic pen 200 modulates the touch signal on the carrier signal to form a modulated signal FM, and scatters the modulated signal FM outwards, and then the transceiver coil 2011 receives the modulated signal FM. The modulated signal FM is demodulated, filtered and waveform shaped to restore the touch signal. The restored touch signal is transmitted to the main control module 10, and the main control module 10 acquires the pressure sensing information and/or key information contained in the touch signal.

The main control module 10 also outputs a gating signal to control the analog switches inside the plurality of switching units 402 to gate one by one, thereby switching the positioning coils 401 respectively connected in series with the respective analog switches at a high speed. The gated positioning coil 401 receives the coordinate SIGNAL pen_signal fed back by the electromagnetic PEN 200, and the electromagnetic field of the position touched by the PEN tip of the electromagnetic PEN 200 is strongest, and the values of the X-axis coordinate SIGNAL and the Y-axis coordinate SIGNAL received by the corresponding X-axis coordinate coil and Y-axis coordinate coil are largest, respectively—for example, the (X3, Y5) point of the PEN tip touch electric PEN handwriting board of the electromagnetic PEN 200, the value of the X-axis coordinate SIGNAL received by the X3-axis coordinate coil is largest among the values of the respective X-axis coordinate SIGNALs received by all the X-axis coordinate coils, and the value of the Y-axis coordinate SIGNAL received by the Y5-axis coordinate coil is largest among the values of the respective Y-axis coordinate SIGNALs received by all the Y-axis coordinate coils.

Each coordinate SIGNAL pen_signal is filtered, amplified in multiple stages, and integrated, and then output to an AD port of the main control module 10, i.e., an analog-to-digital conversion port. The main control module 10 calculates the voltage values of all the acquired coordinate SIGNALs pen_signal, and processes all the voltage values by an bubbling program method to calibrate an X-axis coordinate coil corresponding to an X-axis coordinate SIGNAL with the largest voltage value (hereinafter, the X-axis coordinate coil is denoted by Xmax) and a Y-axis coordinate coil corresponding to a Y-axis coordinate SIGNAL with the largest voltage value (hereinafter, the Y-axis coordinate coil is denoted by Ymax), thereby primarily determining the touch position of the electromagnetic PEN 200, that is, (Xmax, ymax).

The main control module 10 further uploads the touch signal and the touch position information of the electromagnetic pen 200 to the upper computer through a USB interface, an I2C interface or a UART interface, so that the electromagnetic handwriting board completes man-machine interaction. The touch signal contains pressure sensing information and/or key information.

Referring to fig. 8, a specific flowchart of a touch sensing method for an electromagnetic handwriting board according to a second aspect of the present invention is provided, and for convenience of explanation, only the relevant parts of the embodiment are shown, and the detailed description is as follows:

a touch sensing method for an electromagnetic handwriting board comprises a display panel 100, wherein the display panel 100 is used as an operation platform of an electromagnetic pen 200. The touch sensing method comprises the following steps:

S01: the driving signal mod_pwm and the gate signal are generated and output using the main control module 10.

S02: after the carrier module 20 is used to convert the excitation signal mod_pwm into a carrier signal, the carrier signal is transmitted through the transceiver coil 2011, and the transceiver coil receives the modulated signal FM backscattered by the electromagnetic pen, where the modulated signal FM is a touch signal modulated by the electromagnetic pen on the carrier signal.

S03: the processing module 30 is used for processing the modulated signal FM and outputting a touch signal.

S04: the gating module 40 is adopted to successively gate the positioning coils 401 according to the gating signals in a preset sequence so as to receive and output a plurality of X-axis coordinate signals and a plurality of Y-axis coordinate signals fed back by the electromagnetic pen 200; the plurality of positioning coils 401 includes a plurality of X-axis coordinate coils and a plurality of Y-axis coordinate coils.

S05: the main control module 10 is used for receiving the touch signal, the plurality of X-axis coordinate signals and the plurality of Y-axis coordinate signals, and calibrating the X-axis coordinate coil corresponding to the maximum value of the received X-axis coordinate signals and the Y-axis coordinate coil corresponding to the maximum value of the received Y-axis coordinate signals to determine the touch position of the electromagnetic pen 200.

S06: the main control module 10 is adopted to upload the information of the touch signal and the touch position.

The following specifically illustrates the principle of touch sensing method implementation:

In an alternative embodiment, after step S05 and before step S06, step S07 is further included: the gating module 40 sequentially gates the plurality of X-axis coordinate coils adjacent to the calibrated X-axis coordinate coil and the plurality of Y-axis coordinate coils adjacent to the calibrated Y-axis coordinate coil according to the second gating signal in a second preset sequence, so that the plurality of X-axis coordinate coils and the plurality of Y-axis coordinate coils which are secondarily gated receive the X-axis coordinate signal and the Y-axis coordinate signal again.

Before step S07, step S08 is further included: the master control module 10 is used to output the second strobe signal to the strobe module 40.

Since determining the touch position of the electromagnetic pen 200 requires gating all of the positioning coils 401 one after another, scanning each positioning coil 401 causes a delay in signal reception, and an error is inevitably present.

In order to more precisely acquire the touch position information of the electromagnetic PEN 200, the error is reduced as much as possible, after the primary determination of the touch position of the electromagnetic PEN 200, that is, after the calibration (Xmax, ymax) of the combination of coils, the main control module 10 outputs a second gating SIGNAL to the gating module 40, so that a plurality of X-axis coordinate coils (for example, xmax-2, xmax-1, xmax+1, xmax+2) adjacent to the positioning coil 401Xmax and a plurality of Y-axis coordinate coils (for example, ymax-2, ymax-1, ymax+1, ymax+2) adjacent to the positioning coil 401Ymax are secondarily gated, the secondarily gated coils are sequentially gated, and the coordinate SIGNALs pen_signal are received one by one again, and are output to the main control module 10 after being processed by the coordinate SIGNAL processing unit 403, the voltage values are obtained by the main control module 10, and the positioning coils 401Xmax-2, xmax-1, xmax+1 and xmax+2 of the X-axis positioning coil 401 are calibrated, and the positioning coils 401, and the maximum values of the Y-axis coordinate SIGNALs 401, ymax+1 and ymax+2 of the positioning coil 401 and ymax+1 are received.

For example, the twice calibrated positioning coil 401 combination is (Xmax, ymax+2) which is more accurate in position than the initially calibrated positioning coil 401 combination (Xmax, ymax). The main control module 10 outputs the touch position information after the secondary calibration to the upper computer.

In summary, the invention provides a touch sensing device and a method for an electromagnetic handwriting board, wherein the functions of transmitting carrier signals and sampling coordinate signals are realized by different coils, namely, a receiving and transmitting coil transmits carrier signals and receives modulation signals fed back by an electromagnetic pen, and a positioning coil collects X-axis coordinate signals and Y-axis coordinate signals, so that one coil does not need to be multiplexed in a time-sharing way, the receiving and the transmitting of the modulation signals and the receiving of the coordinate signals can be simultaneously performed, the signal processing efficiency is high, and the instantaneity is strong; the receiving and transmitting coil and the positioning coil are connected with different loops, the different loops respectively process the modulation signal and the carrier signal, and the signal processing difficulty is low; the electromagnetic pen can continuously receive the carrier signal and charge and store energy, so that the service life of the battery is prolonged, and the reliability of the electromagnetic pen in operation is improved.

Various embodiments are described herein for various devices, circuits, and methods. Numerous specific details are set forth to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and shown in the accompanying drawings. However, it will be understood by those skilled in the art that the embodiments may be practiced without such specific details. In other instances, well-known operations, components and elements have been described in detail so as not to obscure the embodiments in the specification. It will be appreciated by persons skilled in the art that the embodiments described and illustrated herein are non-limiting examples, and thus it can be appreciated that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the scope of the embodiments.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.

Claims

1. A touch sensing device for an electromagnetic handwriting pad, the electromagnetic handwriting pad comprising a display panel as an operation platform for an electromagnetic pen, the touch sensing device comprising:

The main control module is connected with the carrier module, the processing module and the gating module, and is used for outputting the excitation signal and the gating signal, receiving the touch control signal, a plurality of X-axis coordinate signals and a plurality of Y-axis coordinate signals, calibrating the X-axis coordinate coil corresponding to the maximum value of the received X-axis coordinate signals and the Y-axis coordinate coil corresponding to the maximum value of the received Y-axis coordinate signals, determining the touch control position of the electromagnetic pen on the display panel, and uploading the information of the touch control signal and the touch control position;

The gating module is further used for successively gating a plurality of X-axis coordinate coils adjacent to the calibrated X-axis coordinate coils and a plurality of Y-axis coordinate coils adjacent to the calibrated Y-axis coordinate coils according to a second gating signal according to a second preset sequence, so that the X-axis coordinate coils and the Y-axis coordinate coils which are secondarily gated receive the X-axis coordinate signals and the Y-axis coordinate signals again, and the touch control position of the electromagnetic pen on the display panel is recalibrated.

2. The touch sensing device of claim 1, wherein the carrier module comprises:

the push-pull unit is connected with the main control module and is used for amplifying the excitation signal and outputting the amplified excitation signal; and

The resonance unit is connected with the push-pull unit and comprises a receiving and transmitting coil and a capacitor connected in series with the receiving and transmitting coil, and the resonance unit is used for converting the amplified excitation signal into the carrier signal and transmitting the carrier signal.

3. The touch sensing device of claim 1, wherein the processing module comprises:

the demodulation unit is connected with the carrier module and is used for demodulating the modulated signal and outputting a demodulated signal;

The filtering unit is connected with the demodulation unit and is used for filtering the demodulation signal and outputting a demodulation filtering signal; and

And the shaping unit is connected with the filtering unit and the main control module and is used for outputting the touch control signal to the main control module after performing waveform shaping on the demodulation filtering signal.

4. The touch sensing device of claim 1, wherein the gating module further comprises:

The coordinate signal processing unit is connected with the main control module and is used for carrying out filtering processing, multistage amplification processing and integration processing on the X-axis coordinate signals and the Y-axis coordinate signals and then outputting the signals to the main control module; and

The switch units are respectively and correspondingly connected between the signal processing units and the preset number of positioning coils in series, the switch units are used for receiving the gating signals and correspondingly gating the analog switches in the inner parts so as to enable the corresponding positioning coils to work, and the switch units are also used for outputting the X-axis coordinate signals and the Y-axis coordinate signals to the coordinate signal units.

5. The touch sensing device of claim 1, wherein the transceiver coil is annularly disposed on an edge of a PCB, and a plane of the PCB is parallel to a plane of the display panel.

6. The touch sensing device of claim 1, wherein the plurality of X-axis coordinate coils are perpendicular to the plurality of Y-axis coordinate coils, and a plane in which the plurality of X-axis coordinates and the plurality of Y-axis coordinate coils lie is parallel to a plane in which the display panel lies.

7. The touch sensing device of claim 1, wherein the touch signal comprises pressure sensitive information and/or key information.

8. A touch sensing method for an electromagnetic handwriting board, the electromagnetic handwriting board including a display panel as an operation platform of an electromagnetic pen, the touch sensing method comprising:

The touch control signals, the X-axis coordinate signals and the Y-axis coordinate signals are received by a main control module, the X-axis coordinate coil corresponding to the maximum value of the received X-axis coordinate signals and the Y-axis coordinate coil corresponding to the maximum value of the received Y-axis coordinate signals are calibrated, so that the touch control position of the electromagnetic pen is determined, and the information of the touch control signals and the touch control position is uploaded;

the method further includes, after the step of receiving the touch signal, the plurality of X-axis coordinate signals, and the plurality of Y-axis coordinate signals by using the master control module, calibrating the X-axis coordinate coil corresponding to the maximum value of the received X-axis coordinate signals, and calibrating the Y-axis coordinate coil corresponding to the maximum value of the received Y-axis coordinate signals to determine the touch position of the electromagnetic pen, and before the step of uploading the information of the touch signal and the touch position by using the master control module, further includes:

And sequentially gating a plurality of X-axis coordinate coils adjacent to the calibrated X-axis coordinate coils and a plurality of Y-axis coordinate coils adjacent to the calibrated Y-axis coordinate coils according to a second gating signal by adopting the gating module according to a second preset sequence, so that the X-axis coordinate signals and the Y-axis coordinate signals are received again by the two-time gated X-axis coordinate coils and Y-axis coordinate coils, and the touch control position of the electromagnetic pen on the display panel is recalibrated.

9. The touch sensing method of claim 8, further comprising, before sequentially gating the plurality of X-axis coordinate coils adjacent to the calibrated X-axis coordinate coil and the plurality of Y-axis coordinate coils adjacent to the calibrated Y-axis coordinate coil in a second predetermined order according to a second gating signal by the gating module so that the plurality of X-axis coordinate coils and the plurality of Y-axis coordinate coils which are secondarily gated receive the X-axis coordinate signal and the Y-axis coordinate signal again, the step of:

and outputting the second gating signal to the gating module by adopting the main control module.