阅读说明：本技术 一种用于电磁手写板的触控感应装置及方法 (Touch control induction device and method for electromagnetic handwriting board ) 是由 万力锋 于 2019-09-20 设计创作，主要内容包括：一种用于电磁手写板的触控感应装置及方法,通过载波模块中的收发线圈发射载波信号和接收电磁笔反馈的调制信号；处理模块对调制信号进行处理后还原出触控信号；选通模块包括分别用于接收并输出电磁笔反馈的X轴坐标信号和Y轴坐标信号的多个X轴坐标线圈和多个Y轴坐标线圈；主控模块对接收到X轴坐标信号的最大值对应的X轴坐标线圈和对接收到Y轴坐标信号的最大值对应的Y轴坐标线圈进行标定,以确定电磁笔在显示面板上的触控位置,主控模块还用于上传触控信号和触控位置的信息。上述的触控感应装置及方法,发射载波信号和采样坐标信号的功能由不同线圈实现,无需分时复用一个线圈,信号处理效率高、实时性强、难度小。(A touch control induction device and method for electromagnetic handwriting board, transmit carrier signal and receive modulation signal fed back by electromagnetic pen through receiving and transmitting coil in carrier module; the processing module processes the modulation signal and then restores a 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 calibrates an X-axis coordinate coil corresponding to the maximum value of the received X-axis coordinate signal and a Y-axis coordinate coil corresponding to the maximum value of the received Y-axis coordinate signal to determine the touch position of the electromagnetic pen on the display panel, and is further used for uploading the touch signal and the touch position information. 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 manner, and the touch sensing device and the touch sensing method are high in signal processing efficiency, strong in real-time performance and small in difficulty.)

1. a touch-sensitive device for an electromagnetic writing pad, the electromagnetic writing pad including a display panel, the display panel being an operating platform for an electromagnetic pen, the touch-sensitive device comprising:

the carrier module comprises a receiving and transmitting coil, is used for converting a received excitation signal into a carrier signal and then transmitting the carrier signal through the receiving and transmitting coil, and receives a modulation signal backscattered by the electromagnetic pen through the receiving and transmitting coil, wherein the modulation 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 signal after signal processing is carried out on the modulation signal;

The gating module comprises a plurality of positioning coils, 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 performs gating processing on the plurality of positioning coils one by one according to a gating signal according to 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 used for outputting the excitation signal and the gating signal, receiving the touch signal, 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, determining the touch position of the electromagnetic pen on the display panel, and uploading the touch signal and the information of the touch position.

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

And the resonance unit is connected with the push-pull unit, comprises the transceiving coil and a capacitor connected with the transceiving coil in series, and is used for converting the excitation signal after amplification into the carrier signal and then 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 modulation signal and outputting a demodulation 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 signal to the main control module after the waveform shaping is carried out 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 performing 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 outputting the signals to the main control module; and

the switching units are respectively and correspondingly connected in series between the signal processing unit and the preset number of the positioning coils, the switching units are used for correspondingly gating the internal analog switches when receiving the gating signals so as to enable the corresponding positioning coils to work, and the switching units are further 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 disposed at 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 where the plurality of X-axis coordinates and the plurality of Y-axis coordinate coils are located is parallel to a plane where the display panel is located.

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

8. A touch sensing method for an electromagnetic writing pad, the electromagnetic writing pad comprising a display panel, the display panel being an operating platform of an electromagnetic pen, the touch sensing method comprising:

Generating and outputting an excitation signal and a gating signal by adopting a main control module;

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

a processing module is adopted to carry out signal processing on the modulation signal and then restore and output the touch signal;

a gating module is adopted to gate a plurality of positioning coils one by one 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 a main control module is adopted to receive the touch control signal, the X-axis coordinate signals and the Y-axis coordinate signals, calibrate 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 Y-axis coordinate signals so as to determine the touch control position of the electromagnetic pen, and upload the touch control signal and the information of the touch control position.

9. The touch sensing method of claim 8, wherein 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 a main 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 touch signal and the information of the touch position by using the main control module, the method further comprises:

and gradually 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 by adopting the gating module 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 gated for the second time receive the X-axis coordinate signals and the Y-axis coordinate signals again.

10. the touch sensing method of claim 9, wherein before the step of 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 according to a second gating signal in a second preset order by using the gating module, so that the X-axis coordinate signals and the Y-axis coordinate signals are received again by the plurality of X-axis coordinate coils and the plurality of Y-axis coordinate coils that are secondarily gated, the method further comprises:

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

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, the traditional electromagnetic handwriting screen carries out time-sharing multiplexing by adopting a single antenna, thereby realizing time-sharing signal receiving and transmitting. However, the mode switching of the time-sharing signal receiving and sending mode needs to be repeated, the system is low in efficiency of signal processing, the difficulty of signal processing is high, and the electromagnetic pen can only intermittently charge and store energy, so that the power supply cannot stably supply power, the stability of signals in the system is influenced, and the reliability of the electromagnetic handwriting screen is reduced.

therefore, the conventional magnetic handwriting screen technical scheme has the problems of low system signal processing efficiency, signal processing difficulty and low reliability caused by the repeated mode switching by adopting a time-sharing signal receiving and sending mode.

Disclosure of Invention

in view of this, embodiments of the present invention provide a touch sensing apparatus and method for an electromagnetic handwriting pad, which are used to solve the problems of low signal processing efficiency, high signal processing difficulty and low reliability of a system caused by repeated mode switching in a time-sharing signal receiving and sending manner in the conventional technical solution.

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

The carrier module comprises a receiving and transmitting coil, is used for converting a received excitation signal into a carrier signal and then transmitting the carrier signal through the receiving and transmitting coil, and receives a modulation signal backscattered by the electromagnetic pen through the receiving and transmitting coil, wherein the modulation 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 signal after signal processing is carried out on the modulation signal;

The gating module comprises a plurality of positioning coils, 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 performs gating processing on the plurality of positioning coils one by one according to a gating signal according to 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 used for outputting the excitation signal and the gating signal, receiving the touch signal, 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, determining the touch position of the electromagnetic pen on the display panel, and uploading the touch signal and the information of the touch position.

A second aspect of the embodiments of the present invention provides a touch sensing method for an electromagnetic handwriting pad, where the electromagnetic handwriting pad includes a display panel, the display panel is used as an operating platform of an electromagnetic pen, and the touch sensing module generates and outputs an excitation signal and a gating signal;

Generating and outputting an excitation signal and a gating signal by adopting a main control module;

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

A processing module is adopted to carry out signal processing on the modulation signal and then restore and output the touch signal;

A gating module is adopted to gate a plurality of positioning coils one by one 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 a main control module is adopted to receive the touch control signal, the X-axis coordinate signals and the Y-axis coordinate signals, calibrate 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 Y-axis coordinate signals so as to determine the touch control position of the electromagnetic pen, and upload the touch control signal and the information of the touch control position.

According to the touch control induction device and the touch control induction 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 manner, the modulation signal and the coordinate signal can be received at the same time, the signal processing efficiency is high, and the real-time performance is strong; the receiving and transmitting coil and the positioning coil are connected with different loops, and the different loops respectively process the modulation signal and the carrier signal, so that the signal processing difficulty is small; the electromagnetic pen can continuously receive the carrier signal and perform charging and energy storage, so that the stability and the reliability of the electromagnetic pen during working are improved, and the service life of the battery is prolonged.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic structural diagram of a module of a touch sensing apparatus for an electromagnetic writing pad according to a first aspect of the present invention;

FIG. 2 is a schematic diagram of the wiring of the transceiver coil and the 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 diagram of an exemplary circuit of a carrier module in the touch sensing device shown in FIG. 3;

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

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

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

Fig. 8 is a flowchart illustrating a touch sensing method for an electromagnetic writing pad according to a second aspect of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

referring to fig. 1, a schematic block diagram of a touch sensing device for an electromagnetic writing pad according to a first aspect of the present invention is shown, for convenience of description, only the relevant portions of the embodiment are shown, and the following details are described:

A touch control induction 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 writing pad includes a display panel 100, and the display panel 100 serves as an operation platform for the electromagnetic pen 200.

the carrier module 20 includes a transceiver 2011, the carrier module 20 converts the received excitation signal MOD _ PWM into a carrier signal, and transmits the carrier signal through the transceiver 2011, and the transceiver 2011 receives a modulation signal FM backscattered by the electromagnetic pen 200, where the modulation 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 implemented by using a 32-bit high-speed high-performance ARM single-chip microcomputer as an excitation source. The excitation signal MOD _ PWM is subjected to push-pull amplification by the carrier module 20, resonated by the inductor-capacitor series resonant circuit, and an alternating electromagnetic field appears in the space, that is, a carrier signal is generated and radiated to the space; the carrier signal is a sine wave signal. The electromagnetic pen 200 in the coverage of the carrier signal is triggered to charge and store energy after sensing the alternating electromagnetic field in the space, and backscatters the modulated signal FM outwards by the backscattering principle after modulating the touch signal into the carrier signal.

Because the transceiver coil 2011 is only used for continuously transmitting the carrier signal, the electromagnetic pen 200 can continuously perform wireless charging and energy storage, so that insufficient charging caused by intermittent transmission of the carrier signal is avoided, and the reliability and 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, and therefore, the SIGNAL processing efficiency is high, the real-time performance is strong, and the SIGNAL processing difficulty is small; 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 problem that the modulation process and the emission process of the touch signal are influenced due to insufficient charging caused by too short receiving time of the carrier signal is avoided.

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

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

Specifically, the processing module 30 demodulates, filters and shapes the modulation signal FM, and then 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 serves as an operation platform of the electromagnetic pen 200, so that a user can hold the electromagnetic pen 200 to operate the electromagnetic pen 200, human-computer interaction keys are displayed on the display panel 100, the user can touch corresponding human-computer interaction keys by using the electromagnetic pen 200 according to actual needs, and the electromagnetic pen 200 generates a touch signal containing key information. In addition, the display panel 100 may also be used as a platform for handwriting input, and a user holds the electromagnetic pen 200 to write or draw on the electromagnetic pen, and the touch signal generated by the electromagnetic pen 200 includes pressure information. The touch signal may include both the pressure information and the key information, or may include only the pressure information.

The gating module 40 includes a plurality of positioning coils 401, the plurality of positioning coils 401 include a plurality of X-axis coordinate coils and a plurality of Y-axis coordinate coils, and the gating module 40 gates the plurality of positioning coils 401 one by one according to a preset sequence according to a gating signal, 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 the gating signal to the gating module 40, controls the gating module 40 to gate the positioning coils 401 one by one, and the preset sequence of gating 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 is configured to receive 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 X-axis coordinate coils include 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 include a Y1-axis coordinate coil, a Y2-axis coordinate coil … … Ym-1-axis coordinate coil, and a Ym-axis coordinate coil.

for example, assuming that the electromagnetic pen 200 touches the (X15, Y20) point of the display panel 100 at a certain time, 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 multiple X-axis coordinate signals received by the multiple X-axis coordinate coils, and the value of the Y-axis coordinate signal received by the Y20-axis coordinate coil is the largest among the multiple Y-axis coordinate signals received by the multiple Y-axis coordinate coils, so that after all the positioning coils 401 are gated in one round, the touch position of the electromagnetic pen 200 on the display panel 100 at the certain time can be preliminarily determined to be the (X15, Y20) point.

In order to accurately acquire the touch position information of the electromagnetic pen 200 and minimize the error, after preliminarily determining that the position touched by the electromagnetic pen on the display panel at this time is the (X15, Y20) point, 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, i.e., again scans the coil X15 and a plurality of X-axis coordinate coils adjacent to the coil X15, and again scans the coil Y20 and a plurality of Y-axis coordinate coils adjacent to the coil Y20, and accurately calculates and recalibrates the position touched by 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 with the transmitting carrier SIGNAL or the receiving 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 reused as a receiving and transmitting coil, and is only used for receiving the coordinate SIGNAL PEN _ SIGNAL, so that the SIGNAL processing difficulty is small, and the SIGNAL processing efficiency is improved by nearly one time. The coordinate SIGNALs PEN _ SIGNAL are all referred to as X-axis coordinate SIGNALs and Y-axis coordinate SIGNALs throughout the text.

The main control module 10 is configured to output an excitation signal MOD _ PWM and a gating 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, so as to determine a touch position of the electromagnetic pen 200 on the display panel 100, where the main control module 10 is further configured to upload the touch signal and information of the touch position. The information of the touch position is included in the X-axis coordinate signal and the Y-axis coordinate signal.

Specifically, the main control module 10 uploads the touch signal and the coordinate information of 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 that the original handwriting is highly restored and presented. The main control module 10 communicates with the upper computer through its own USB interface, I2C interface or UART interface, and uploads the touch signal and the information of the touch position to the upper computer.

Fig. 2 is a schematic diagram of the wiring of the transceiver coil and the positioning coil in the touch sensing device shown in fig. 1, which only shows the parts related to the present embodiment for convenience of description, and the following details are described below:

Optionally, the transceiver coil 2011 and the positioning coil 401 are distributed on the PCB. The transceiver coil 2011 is disposed around the edge of the PCB, and the plane of the PCB is parallel to the plane of the display panel 100. The plane where the plurality of positioning coils 401 are located is parallel to the plane where the display panel 100 is located, wherein the plurality of X-axis coordinate coils are perpendicular to the plurality of 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 control induction device, and the touch control induction 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 positioning coils 401 are commonly connected, the other ends of the 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 the coordinate SIGNAL PEN _ SIGNAL through the corresponding switching unit 402. The transceiver coil 2011 is connected to the processing module 30 and the carrier module 20.

please refer to fig. 3, which is a schematic diagram of a unit structure of the touch sensing device shown in fig. 1, for convenience of description, only the parts related to the present embodiment are shown, and the details are 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 transceiver coil 2011 and a capacitor connected in series with the transceiver 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 the capacitor connected in series therewith form an inductor-capacitor series resonance circuit, and a sine wave signal is generated by resonance, so that an alternating electromagnetic field appears in the space, and the sine wave signal is a carrier signal.

in an alternative embodiment, the processing module 30 includes a demodulating 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 transmitting/receiving coil 2011 outputs the received modulation signal FM to the demodulating unit 301, and the demodulating unit 301 demodulates the received modulation signal FM and outputs the demodulated signal to the filtering unit 302.

The filtering unit 302 is configured to filter the demodulated signal and output a demodulated 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 filtered signal. Specifically, the touch signal includes pressure information and/or key information.

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

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

the plurality of switch units 402 are configured to gate the internal analog switches correspondingly when receiving the gate SIGNAL, so that the corresponding positioning coils 401 operate, and the plurality of switch units 402 are further 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 therein, and each analog switch is connected in series between the non-grounded 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 the gating SIGNAL output by the main control module 10, and the gated analog switch connects the positioning coil 401 connected thereto 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, multistage amplification, and integration on the multiple X-axis coordinate signals and the multiple Y-axis coordinate signals, and output the processed 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 uses a corresponding program to obtain a voltage value of the X-axis coordinate signal or the Y-axis coordinate signal, and processes the plurality of voltage values through a bubbling program to obtain a maximum value of the plurality of X-axis coordinate signals and a maximum value of the plurality of Y-axis coordinate signals, where the maximum value is a 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 finding the maximum value of the plurality of X-axis coordinate signals and the maximum value of the plurality of Y-axis coordinate signals and calibrating the two.

Referring to fig. 4, a schematic circuit diagram of an example of the carrier module 20 in the touch sensing device shown in fig. 3 is shown, for convenience of description, only the parts related to the present embodiment are shown, and the following details are described:

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 transceiver coil 2011, a capacitor C8, a capacitor C9, and a capacitor C10.

A first end of the capacitor C5 is connected to the main control module 10 to receive the 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 connected in common, 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 of the NPN triode Q3, and the emitter of the NPN triode Q3 is grounded.

A first end of the resistor R15 and a collector of the NPN triode Q1 are connected with a working power supply, a second end of the resistor R15, an anode of the diode D1 and a base of the NPN triode Q1 are connected in common, a cathode of the diode D1 is connected with an anode of the diode D3, a cathode of the diode D3 is connected with a collector of the NPN triode Q3, and an emitter of the NPN triode Q1 is connected with a 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 connected in common, the second end of the resistor R5 is connected with the emitter of a 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 a diode D3.

the second end of the resistor R64 is connected to the first end of the positioning coil 401, 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 connected in common, and the second end of the capacitor C8, the second end of the capacitor C9 and the second end of the capacitor C10 are connected to ground.

The NPN triode Q1 and the PNP triode Q2 jointly form a push-pull circuit, the emitting electrodes of the NPN triode Q1 and the PNP triode Q2 are connected in common through a resistor R4 and a resistor R5 respectively, and the common connection point is used as the 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 inductor-capacitor series resonance circuit, and is composed of a positioning coil 401, a capacitor C8, a capacitor C9 and a capacitor C10, an excitation signal MOD _ PWM output after being amplified by push-pull generates resonance through the resonance unit 201, so that a sine wave signal is generated, an alternating electromagnetic field appears in a space, the sine wave signal is a carrier signal, and the electromagnetic pen 200 within the coverage range of the carrier signal is triggered after receiving the carrier signal, charges, stores energy and feeds back a modulation signal FM.

Fig. 5 is a schematic circuit diagram of an exemplary circuit of the processing module 30 in the touch sensing device shown in fig. 3, which only shows the relevant parts of the present embodiment for convenience of description, and the following details are described:

the processing module 30 includes 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 comprises 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 transistor Q4.

The anode of the diode D2 is connected to the second terminal of the transceiving coil 2011 for receiving the modulation signal FM sensed by the transceiving coil 2011, the cathode of the diode D2, the first terminal of the capacitor C6 and the first terminal of the resistor R7 are connected together, and the second terminal of the capacitor C6 and the second terminal of the resistor R7 are connected to ground.

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

the second end of the resistor R14 is connected with the output end of the comparator, the positive phase input end of the comparator U5-A, the positive phase input end of the comparator U5-B, the first end of the resistor R11 and the first end of the resistor R10 are connected in common, 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 out dc interference signals. The output end of the comparator U5-B is connected to the main control module 10, and is configured to output the recovered touch signal after demodulating, filtering, shaping, and conditioning the modulation signal FM, and the recovered 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 exemplary circuit of the coordinate signal processing unit 403 in the touch sensing device shown in fig. 3 is shown, and for convenience of description, only the parts related to the present embodiment are shown, and detailed descriptions 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 R, a resistor 23, a resistor R, a capacitor C, an amplifier U-A, an amplifier U-B, an amplifier U-C, an amplifier U-D, an amplifier U-A, an amplifier U-C, an amplifier U-channel FET Q, a diode D, a resistor R, a, Diode D11, diode D10, and NPN transistor Q6.

A first terminal of the capacitor C43 is connected to the switch unit 402 for receiving the coordinate SIGNAL PEN _ SIGNAL, a second terminal of the capacitor C43, a first terminal of the resistor R29 and a non-inverting input terminal of the amplifier U16-a are connected in common, and an inverting input terminal of the amplifier U16-a, a first terminal of the resistor R28 and a first terminal of the R resistor 30 are connected in common; the second end of the resistor R30 and the first end of the resistor R30, namely the output end of the amplifier U16-A, 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 connected in common, 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 connected in common.

the second end of the resistor R33, the output end of the amplifier U16-D and the positive phase input end of the amplifier U16-C are connected in common, 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 connected in common, the second end of the resistor R27, the output end of the amplifier U16-C and the first end of the capacitor C42 are connected in common, and the second end of the capacitor C42, the first end of the resistor R23 and the positive phase input end of the amplifier U16-B are connected in common; the inverting input terminal of the amplifier U16-B, the first terminal of the resistor R24 and the first terminal of the resistor R25 are connected in common, and the second terminal of the resistor R25, the output terminal of the amplifier U16-B and the first terminal of the capacitor C41 are connected in common.

The second end of the capacitor C41 and the first end of the resistor R35 are connected in common, the second end of the resistor R35, the drain of the N-channel fet Q5 and the first end of the resistor 34 are connected in common, the gate of the N-channel fet Q5, the first end of the resistor R46 and the anode of the diode D11 are connected in common, the cathode of the diode D11 is connected to the anode of the diode D6, the cathode of the diode D6 is connected to the anode of the diode D9, the cathode of the diode D9 is connected to the anode of the diode D7, the cathode of the diode D7 is connected to the first end of the resistor R45, and the first end of the resistor R45 and the source of the N-channel fet Q5 are connected in; the second end of the resistor R46 is connected to the main control module 10.

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

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

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

Specifically, a first terminal of the capacitor C43 serves as an input terminal of the coordinate SIGNAL processing unit 403, and is connected to the switch unit 402 for receiving the coordinate SIGNAL PEN _ SIGNAL. The input coordinate SIGNAL PEN _ SIGNAL is subjected to multi-stage operational amplification, filtering and integration by the circuit of the coordinate SIGNAL processing unit 403, and then the optimized coordinate SIGNAL is output to the analog-to-digital conversion interface, i.e., POS _ AD port, of the main control module 10, the voltage value of the coordinate SIGNAL PEN _ SIGNAL is obtained by the main control module 10 and compared, and the X-axis coordinate coil corresponding to the maximum value of the X-axis coordinate SIGNAL and the Y-axis coordinate coil corresponding to the maximum value of the Y-axis coordinate SIGNAL are calibrated.

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 integrating capacitor emptying SIGNAL DICH for emptying the integrating capacitor, and when the coordinate SIGNAL processing unit 403 finishes sampling one coordinate SIGNAL PEN _ SIGNAL, the integrating capacitor in the circuit is emptied before sampling the next coordinate SIGNAL PEN _ SIGNAL.

Referring to fig. 7, a schematic diagram of an exemplary circuit of the switch unit 402 in the touch sensing device shown in fig. 3 is shown, and for convenience of description, only the parts related to the present embodiment are shown, and the following details are described:

The gating module 40 includes a coordinate signal processing unit 403 and a plurality of switch units 402, each switch unit 402 includes eight analog switches, and each analog switch is correspondingly connected in series between the non-grounded 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 the gating SIGNAL output by the main control module 10, and the gated analog switch connects the positioning coil 401 connected thereto 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 switch unit 402 is implemented by an 8-to-1 data selector, each 8-to-1 data selector includes 8 analog switches, and gates the corresponding analog switches according to the received 4-way gating signal (INH, C, B, a).

The 4-path gating signals are binary codes, and when and only when the gating signal INH is 0, one of the 8 analog switches is closed. Taking 4-way gating signals (INH, C, B, a) as (0, 1, 0, 0) respectively as an example, the analog switch which is closed at this time is the 5 th analog switch, namely the analog switch with the number of 04, and the rest 7 analog switches are not closed; assuming that the analog switch 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 number 04, which is subjected to filtering, multi-stage operational amplification, and integration processing by the coordinate SIGNAL processing unit 403.

The main control module 10 outputs 4-way gate signals to the switch unit 402, and the working states of the 4-way gate signals INH, a, B and C and the 8 analog switches 00, 01, 02, 03, 04, 05, 06 and 07 have the following relationships as 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 program initialization. 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 the excitation signal MOD _ PWM is subjected to push-pull amplification, the inductor-capacitor series resonant circuit is driven, a low-frequency carrier signal is transmitted by the transceiver coil 2011, and an alternating electromagnetic field is generated in a space. The electromagnetic pen 200 within the coverage 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 onto the carrier signal to form a modulation signal FM, scatters the modulation signal FM outwards, and receives the modulation signal FM through the transceiver coil 2011. And after demodulation, filtering and waveform shaping processing are carried out on the modulation signal FM, the touch signal is restored. The restored touch signal is transmitted to the main control module 10, and the main control module 10 obtains pressure information and/or key information included in the touch signal.

the main control module 10 further outputs a gating signal to control the analog switches in the switch units 402 to gate one by one, so as to switch the positioning coils 401 respectively connected in series with the analog switches at a high speed. The gated positioning coil 401 receives the coordinate SIGNAL PEN _ SIGNAL fed back by the electromagnetic PEN 200, the electromagnetic field of the position touched by the PEN tip of the electromagnetic PEN 200 is strongest, 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, respectively, are the largest — for example, at the point (X3, Y5) of the PEN-tip touch-control PEN writing pad of the electromagnetic PEN 200, the value of the X-axis coordinate SIGNAL received by the X3-axis coordinate coil is the 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 the 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, where the AD port is an analog-to-digital conversion port. The main control module 10 calculates voltage values of all the acquired coordinate SIGNALs PEN _ SIGNAL, processes all the voltage values by a bubbling program method, and calibrates an X-axis coordinate coil corresponding to an X-axis coordinate SIGNAL with a maximum voltage value (hereinafter, Xmax indicates the X-axis coordinate coil) and a Y-axis coordinate coil corresponding to a Y-axis coordinate SIGNAL with a maximum voltage value (hereinafter, Ymax indicates the Y-axis coordinate coil), thereby preliminarily determining a 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 an upper computer through a USB interface, an I2C interface, or a UART interface, so that the electromagnetic handwriting board completes human-computer interaction. The touch signal includes pressure information and/or key information.

Referring to fig. 8, a specific flowchart of a touch sensing method for an electromagnetic writing pad according to a second aspect of the present invention is shown, for convenience of description, only the relevant portions of the embodiment are shown, and the following details are described:

A touch sensing method for an electromagnetic writing pad 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 master control module 10 is adopted to generate and output the excitation signal MOD _ PWM and the gating signal.

s02: after the excitation signal MOD _ PWM is converted into a carrier signal by the carrier module 20, the carrier signal is transmitted through the transceiver coil 2011, and the transceiver coil receives a modulation signal FM backscattered by the electromagnetic pen, where the modulation signal FM is a touch signal modulated on the carrier signal by the electromagnetic pen.

S03: the processing module 30 is used for performing signal processing on the modulation signal FM and then outputting a touch signal.

s04: the gating module 40 is adopted to gate the plurality of positioning coils 401 one by one according to the 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; 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 adopted to receive the touch signal, the plurality of X-axis coordinate signals and the plurality of Y-axis coordinate signals, and calibrate 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 position of the electromagnetic pen 200.

s06: the main control module 10 is adopted to upload the touch signal and the touch position information.

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

The main control module 10 is powered on to complete the program initialization. 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 the excitation signal MOD _ PWM is subjected to push-pull amplification, the inductor-capacitor series resonant circuit is driven, a low-frequency carrier signal is transmitted by the transceiver coil 2011, and an alternating electromagnetic field is generated in a space. The electromagnetic pen 200 within the coverage 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 onto the carrier signal to form a modulation signal FM, scatters the modulation signal FM outwards, and receives the modulation signal FM through the transceiver coil 2011. And after demodulation, filtering and waveform shaping processing are carried out on the modulation signal FM, the touch signal is restored. The restored touch signal is transmitted to the main control module 10, and the main control module 10 obtains pressure information and/or key information included in the touch signal.

the main control module 10 further outputs a gating signal to control the analog switches in the switch units 402 to gate one by one, so as to switch the positioning coils 401 respectively connected in series with the analog switches at a high speed. The gated positioning coil 401 receives the coordinate SIGNAL PEN _ SIGNAL fed back by the electromagnetic PEN 200, the electromagnetic field of the position touched by the PEN tip of the electromagnetic PEN 200 is strongest, 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, respectively, are the largest — for example, at the point (X3, Y5) of the PEN-tip touch-control PEN writing pad of the electromagnetic PEN 200, the value of the X-axis coordinate SIGNAL received by the X3-axis coordinate coil is the 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 the 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, where the AD port is an analog-to-digital conversion port. The main control module 10 calculates voltage values of all the acquired coordinate SIGNALs PEN _ SIGNAL, processes all the voltage values by a bubbling program method, and calibrates an X-axis coordinate coil corresponding to an X-axis coordinate SIGNAL with a maximum voltage value (hereinafter, Xmax indicates the X-axis coordinate coil) and a Y-axis coordinate coil corresponding to a Y-axis coordinate SIGNAL with a maximum voltage value (hereinafter, Ymax indicates the Y-axis coordinate coil), thereby preliminarily determining a 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 an upper computer through a USB interface, an I2C interface, or a UART interface, so that the electromagnetic handwriting board completes human-computer interaction. The touch signal includes pressure information and/or key information.

in an alternative embodiment, after step S05 and before step S06, the method further includes step S07: and gradually gating a plurality of X-axis coordinate coils adjacent to the calibrated X-axis coordinate coil and a plurality of Y-axis coordinate coils adjacent to the calibrated Y-axis coordinate coil according to a second gating signal by using a gating module 40 according to a second preset sequence, so that the plurality of secondarily gated X-axis coordinate coils and the plurality of secondarily gated Y-axis coordinate coils receive the X-axis coordinate signal and the Y-axis coordinate signal again.

Before step S07, step S08 is further included: and outputting the second gating signal to the gating module 40 by using the main control module 10.

Since the touch position of the electromagnetic pen 200 needs to be determined by sequentially gating all the positioning coils 401, scanning each positioning coil 401 causes a delay in signal reception, and an error inevitably exists.

In order to more accurately acquire the touch position information of the electromagnetic PEN 200 and minimize the error, the main control module 10 outputs the second gating SIGNAL to the gating module 40 after preliminarily determining the touch position of the electromagnetic PEN 200, i.e., after calibrating the (Xmax, Ymax) coil combination, such that a plurality of X-axis coordinate coils (e.g., Xmax-2, Xmax-1, Xmax +2) adjacent to the Xmax of the positioning coil 401 and a plurality of Y-axis coordinate coils (e.g., Ymax-2, Ymax-1, Ymax +2) adjacent to the Ymax of the positioning coil 401 are secondarily gated, the secondarily gated coils are sequentially gated, and the coordinate SIGNALs PEN _ SIGNAL are received one by one, processed by the coordinate SIGNAL processing unit 403 and output to the main control module 10, and the main control module 10 determines the voltage value and calibrates the Xmax-2, Xmax-1, Ymax +2, Ymax +1, Ymax +2, and Ymax +, The positioning coils 401 receiving the maximum value of the X-axis coordinate signal among the Xmax-1, Xmax +1, and Xmax +2, and the positioning coils 401 receiving the maximum value of the Y-axis coordinate signal among the Y-axis positioning coils 401Ymax-2, Ymax-1, Ymax +1, and Ymax +2 are calibrated in the same manner.

For example, the positioning coils 401 of the secondary calibration are combined to be (Xmax, Ymax +2), which is more accurate in position than the positioning coils 401 of the primary calibration (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 method for electromagnetic handwriting board, the functions of transmitting carrier signal and sampling coordinate signal are realized by different coils, that is, the receiving and transmitting coil transmits carrier signal and receives modulation signal fed back by electromagnetic pen, the positioning coil collects X axis coordinate signal and Y axis coordinate signal, thus one coil does not need time-sharing multiplexing, the receiving of modulation signal and the receiving of coordinate signal can be performed at the same time, the signal processing efficiency is high, and the real-time performance is strong; the receiving and transmitting coil and the positioning coil are connected with different loops, and the different loops respectively process the modulation signal and the carrier signal, so that the signal processing difficulty is small; the electromagnetic pen can continuously receive the carrier signal and carry out charging and energy storage, the service life of the battery is prolonged, and the reliability of the electromagnetic pen during working is improved.

Various embodiments are described herein for various apparatuses, circuits, and methods. Numerous specific details are set forth in order to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and illustrated 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 description. It will be appreciated by those of ordinary skill in the art that the embodiments herein and shown 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 implementation. 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 present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.