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 2019-09-23 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,切换模块将X轴线圈切换至载波模块并将Y轴线圈同步切换至坐标模块,或将Y轴线圈切换至载波模块并将X轴线圈同步切换至坐标模块；且选通模块逐次选通多个X轴线圈和多个Y轴线圈,实现当X轴线圈发射载波信号并接收电磁笔反馈的调制信号时Y轴线圈接收坐标信号；当Y轴线圈发射载波信号并接收电磁笔反馈的调制信号时X轴线圈接收坐标信号。因此保证了不间断向电磁笔发射载波信号,实现同步发射载波信号和接收坐标信号,收发信号的时长不再相互限制,电磁笔无线充电、不间断蓄能,接收坐标信号的实时性高,降低了延迟作用,精度高；且载波模块处理调制信号,坐标模块处理坐标信号,信号处理效率高。(a touch control induction device and method for electromagnetic handwriting board, the switching module switches the X-axis coil to the carrier module and synchronously switches the Y-axis coil to the coordinate module, or switches the Y-axis coil to the carrier module and synchronously switches the X-axis coil to the coordinate module; the gating module gates the plurality of X-axis coils and the plurality of Y-axis coils one by one, so that the Y-axis coils receive coordinate signals when the X-axis coils transmit carrier signals and receive modulation signals fed back by the electromagnetic pen; and when the Y-axis coil transmits a carrier signal and receives a modulation signal fed back by the electromagnetic pen, the X-axis coil receives a coordinate signal. Therefore, the uninterrupted transmission of the carrier signal to the electromagnetic pen is ensured, the synchronous transmission of the carrier signal and the synchronous reception of the coordinate signal are realized, the time length of signal transmission and reception is not limited mutually, the electromagnetic pen is charged wirelessly and is subjected to uninterrupted energy storage, the real-time performance of the reception of the coordinate signal is high, the delay effect is reduced, and the precision is high; and the carrier module processes the modulation signal, and the coordinate module processes the coordinate signal, so that the signal processing efficiency is high.)

1. A touch sensing device for an electromagnetic writing pad, comprising:

The touch control system comprises a plurality of X-axis coils and a plurality of Y-axis coils, wherein each X-axis coil and each Y-axis coil are used for transmitting a carrier signal when being gated and receiving a modulation signal output after an electromagnetic pen modulates a touch control signal of the electromagnetic pen, or receiving a coordinate signal fed back by the electromagnetic pen when being gated;

The gating module is connected with the X-axis coils and the Y-axis coils and is used for gating the X-axis coils and the Y-axis coils one by one according to a gating signal in a preset sequence and gating only one X-axis coil and one Y-axis coil in each period of the gating signal;

The carrier module is used for converting the received excitation signal into a carrier signal, and outputting the touch signal after performing signal processing on the received modulation signal;

The coordinate module is used for outputting an optimized coordinate signal after the received coordinate signal is subjected to signal processing;

the switching module is used for communicating the gated X-axis coil with the carrier module and communicating the gated Y-axis coil with the coordinate module when receiving a first switching signal, or communicating the gated X-axis coil with the coordinate module and communicating the gated Y-axis coil with the carrier module when receiving a second switching signal;

the main control module is connected with the gating module, the switching module, the carrier module and the coordinate module, and is used for outputting the gating signal, the first switching signal and the second switching signal, receiving the touch signal and the optimized coordinate signal, calibrating the X-axis coil and the Y-axis coil which receive the maximum value of the coordinate signal, determining the touch position of the electromagnetic pen, 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;

The resonance unit is connected with the push-pull unit and is connected with the X-axis coil and the Y-axis coil through the gating module, and the resonance unit is used for converting the amplified excitation signal into the carrier signal;

The demodulation unit is connected with the X-axis coil and the Y-axis coil through the gating 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.

3. The touch sensing device of claim 1, wherein the coordinate module is configured to perform filtering, multi-stage amplification, and integration on the plurality of coordinate signals and output the coordinate signals to the main control module.

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

The first switch unit is connected between the switching module and the X-axis coils in series, and is used for correspondingly gating the internal analog switches when receiving the gating signals so as to enable the corresponding X-axis coils to work; and

And the second switch units are connected between the switching module and the preset number of the Y-axis coils in series, and are used for correspondingly gating the internal analog switches when receiving the gating signals so as to enable the corresponding Y-axis coils to work.

5. The touch sensing device of claim 1, wherein the switching module comprises:

A four-channel single-pole double-throw switch and an inverter;

the four-channel single-pole double-throw switch comprises a first normally closed end, a second normally closed end, a third normally closed end, a fourth normally closed end, a first normally open end, a second normally open end, a third normally open end, a fourth normally open end, a first controlled end, a second controlled end, a first common end, a second common end, a third common end and a fourth common end;

The first normally closed end and the third normally closed end are connected together and then are connected into the coordinate module, and the second normally closed end and the third normally closed end are connected together and then are connected into the coordinate module; the first normally open end and the third normally open end are connected together and then are accessed into the carrier module, and the second normally open end and the fourth normally open end are connected together and then are accessed into the carrier module;

The first common end is connected with one ends of the X-axis coils, and the second common end is connected with the other ends of the X-axis coils; the third common end is connected with one ends of the Y-axis coils, and the fourth common end is connected with the other ends of the Y-axis coils;

the first controlled end and the input end of the phase inverter are connected together and then connected with the main control module, and the second controlled end is connected with the output end of the phase inverter.

6. The touch sensing device of claim 1, wherein the plurality of X-axis coils are perpendicular to the plurality of Y-axis coils, and a plane in which the plurality of X-axis coils and the plurality of Y-axis coils are located is parallel to a plane in which the electromagnetic writing pad 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 touch sensing method comprising:

outputting a gating signal, a first switching signal or a second switching signal by adopting a main control module;

A gating module is adopted to gate a plurality of X-axis coils and a plurality of Y-axis coils one by one according to the gating signal in a preset sequence, and only one X-axis coil and one Y-axis coil are gated in each period of the gating signal;

When the switching module is adopted to receive the first switching signal, the gated X-axis coil is switched to the carrier module, and the gated Y-axis coil is switched to the coordinate module;

when the switching module is adopted to receive the second switching signal, the gated Y-axis coil is switched to the carrier module, and the gated X-axis coil is switched to the coordinate module;

When the X-axis coil is switched to the carrier module and the Y-axis coil is switched to the coordinate module, the X-axis coil is adopted to transmit a carrier signal and receive a modulation signal output after an electromagnetic pen modulates a touch signal of the X-axis coil and the Y-axis coil is adopted to receive a coordinate signal fed back by the electromagnetic pen;

when the X-axis coil is switched to the coordinate module and the Y-axis coil is switched to the carrier module, the Y-axis coil is adopted to transmit the carrier signal and receive the modulation signal, and the X-axis coil is adopted to receive the coordinate signal;

The carrier module is adopted to convert the received excitation signal into the carrier signal so as to be transmitted by the X-axis coil or the Y-axis coil, and the modulation signal received by the X-axis coil or the Y-axis coil is subjected to signal processing and then the touch signal is output to the main control module;

a coordinate module is adopted to perform signal processing on the coordinate signal and then output an optimized coordinate signal to the main control module;

And calibrating the X-axis coil and the Y-axis coil which receive the maximum value of the coordinate signal by adopting a main control module to determine the touch position of the electromagnetic pen and upload the touch signal and the information of the touch position.

9. the touch sensing method according to claim 8, further comprising, after the step of sequentially gating a plurality of X-axis coils and a plurality of Y-axis coils according to a preset sequence by using a gating module according to the gating signal and gating only one X-axis coil and one Y-axis coil in each period of the gating signal, and before the step of uploading the touch signal and the information of the touch position by using the main control module, the step of:

and sequentially gating a plurality of X-axis coils adjacent to the calibrated X-axis coil and a plurality of Y-axis coils adjacent to the calibrated Y-axis coil according to a second gating signal by adopting the gating module according to a second preset sequence, so that the secondarily gated X-axis coils and the secondarily gated Y-axis coils respectively receive the coordinate signals again.

10. the touch sensing method of claim 9, wherein before the step of sequentially gating the plurality of X-axis coils adjacent to the calibrated X-axis coil and the plurality of Y-axis coils adjacent to the calibrated Y-axis coil according to a second gating signal in a second preset order by using the gating module, so that the secondarily gated X-axis coils and the secondarily gated Y-axis coils respectively receive the coordinate signal again ", 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, a traditional electromagnetic handwriting screen adopts a time division multiplexing technology, a carrier wave is transmitted and position information of an electromagnetic pen is received through a single coil in a time division mode, the coil cannot receive signals when transmitting the signals, and the coil cannot transmit the signals when receiving the signals. According to the method for multiplexing the single coil in the time-sharing mode, if the time for transmitting the signal is too short, the resonance energy storage of the electromagnetic pen is insufficient; if the time for receiving the signal is too short, the position information is delayed to be received, the real-time performance is low, and the precision is not enough, namely, the time length for receiving the signal by the coil and the time length for transmitting the signal are limited mutually, so that the signal processing efficiency is low, and the processing difficulty is high.

Therefore, the conventional electromagnetic handwriting input technical scheme has the problems that the time length of receiving signals and the time length of transmitting signals are limited by adopting a time-sharing signal receiving and transmitting method, the signal processing efficiency is low, and the processing difficulty is high.

Disclosure of Invention

In view of this, embodiments of the present invention provide a touch sensing apparatus and method for an electromagnetic handwriting pad, and aim to solve the problems in the conventional technical solutions that the time length of receiving a signal and the time length of transmitting a signal are limited by using a time-sharing signal receiving and transmitting method, the signal processing efficiency is low, and the processing difficulty is high.

A first aspect of an embodiment of the present invention provides a touch sensing device for an electromagnetic writing pad, including:

The touch control system comprises a plurality of X-axis coils and a plurality of Y-axis coils, wherein each X-axis coil and each Y-axis coil are used for transmitting a carrier signal when being gated and receiving a modulation signal output after an electromagnetic pen modulates a touch control signal of the electromagnetic pen, or receiving a coordinate signal fed back by the electromagnetic pen when being gated;

the gating module is connected with the X-axis coils and the Y-axis coils and is used for gating the X-axis coils and the Y-axis coils one by one according to a gating signal in a preset sequence and gating only one X-axis coil and one Y-axis coil in each period of the gating signal;

the carrier module is used for converting the received excitation signal into a carrier signal, and outputting the touch signal after performing signal processing on the received modulation signal;

the coordinate module is used for outputting an optimized coordinate signal after the received coordinate signal is subjected to signal processing;

the switching module is used for communicating the gated X-axis coil with the carrier module and communicating the gated Y-axis coil with the coordinate module when receiving a first switching signal, or communicating the gated X-axis coil with the coordinate module and communicating the gated Y-axis coil with the carrier module when receiving a second switching signal;

the main control module is connected with the gating module, the switching module, the carrier module and the coordinate module, and is used for outputting the gating signal, the first switching signal and the second switching signal, receiving the touch signal and the optimized coordinate signal, calibrating the X-axis coil and the Y-axis coil which receive the maximum value of the coordinate signal, determining the touch position of the electromagnetic pen, and uploading the touch signal and the information of the touch position.

A second aspect of an embodiment of the present invention provides a touch sensing method for an electromagnetic handwriting board, including:

Outputting a gating signal, a first switching signal or a second switching signal by adopting a main control module;

a gating module is adopted to gate a plurality of X-axis coils and a plurality of Y-axis coils one by one according to the gating signal in a preset sequence, and only one X-axis coil and one Y-axis coil are gated in each period of the gating signal;

When the switching module is adopted to receive the first switching signal, the gated X-axis coil is switched to the carrier module, and the gated Y-axis coil is switched to the coordinate module;

When the switching module is adopted to receive the second switching signal, the gated Y-axis coil is switched to the carrier module, and the gated X-axis coil is switched to the coordinate module;

When the X-axis coil is switched to the carrier module and the Y-axis coil is switched to the coordinate module, the X-axis coil is adopted to transmit a carrier signal and receive a modulation signal output after an electromagnetic pen modulates a touch signal of the X-axis coil and the Y-axis coil is adopted to receive a coordinate signal fed back by the electromagnetic pen;

When the X-axis coil is switched to the coordinate module and the Y-axis coil is switched to the carrier module, the Y-axis coil is adopted to transmit the carrier signal and receive the modulation signal, and the X-axis coil is adopted to receive the coordinate signal;

The carrier module is adopted to convert the received excitation signal into the carrier signal so as to be transmitted by the X-axis coil or the Y-axis coil, and the modulation signal received by the X-axis coil or the Y-axis coil is subjected to signal processing and then the touch signal is output to the main control module;

A coordinate module is adopted to perform signal processing on the coordinate signal and then output an optimized coordinate signal to the main control module;

And calibrating the X-axis coil and the Y-axis coil which receive the maximum value of the coordinate signal by adopting a main control module to determine the touch position of the electromagnetic pen and upload the touch signal and the information of the touch position.

according to the touch control induction device and method for the electromagnetic handwriting board, the X-axis coil is switched to the carrier module and the Y-axis coil is synchronously switched to the coordinate module through the switching module, or the Y-axis coil is switched to the carrier module and the X-axis coil is synchronously switched to the coordinate module; the gating module gates the plurality of X-axis coils and the plurality of Y-axis coils one by one according to a preset sequence, so that when the X-axis coils transmit carrier signals and receive modulation signals fed back by the electromagnetic pen, the Y-axis coils receive coordinate signals; when the Y-axis coil transmits a carrier signal and receives a modulation signal fed back by the electromagnetic pen, the X-axis coil receives a coordinate signal. Therefore, uninterrupted transmission of the carrier signal to the electromagnetic pen is guaranteed, synchronous transmission of the carrier signal and synchronous reception of the coordinate signal are achieved, the time length for receiving and transmitting the signal is not limited, the electromagnetic pen is charged wirelessly and is subjected to uninterrupted energy storage, the real-time performance for receiving the coordinate signal is high, the delay effect is reduced, and the precision is high; and the carrier module processes the modulation signal, and the coordinate module processes the coordinate signal, so that the signal processing efficiency is high.

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 a unit structure of the touch sensing device shown in FIG. 1;

FIG. 3 is a schematic diagram of the wiring of the coil in 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. 2;

FIG. 5 is a schematic diagram of an exemplary circuit of a coordinate module in the touch sensing device shown in FIG. 2;

FIG. 6 is a schematic circuit diagram illustrating an exemplary first switch unit of the touch sensing device shown in FIG. 2;

FIG. 7 is a schematic diagram of an exemplary circuit of a second switch unit in the touch sensing device shown in FIG. 2;

FIG. 8 is a schematic diagram of an exemplary circuit of a switching module in the touch sensing device shown in FIG. 2;

Fig. 9 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.

fig. 1 is a schematic structural diagram of a module of a touch sensing device for an electromagnetic writing pad according to a first aspect of the embodiment of the present invention, which only shows parts related to the embodiment for convenience of description, and the detailed description is as follows:

A touch sensing device for an electromagnetic writing pad comprises a main control module 10, a switching module 20, a gating module 30, a carrier module 40, a coordinate module 50, a plurality of X-axis coils 60 and a plurality of Y-axis coils 70.

The gating module 30 is connected to the plurality of X-axis coils 60 and the plurality of Y-axis coils 70, the switching module 20 is connected to the gating module 30, the plurality of X-axis coils 60, the plurality of Y-axis coils 70, the carrier module 40 and the coordinate module 50, and the main control module 10 is connected to the gating module 30, the switching module 20, the carrier module 40 and the coordinate module 50.

each X-axis coil 60 and each Y-axis coil 70 are used for transmitting a carrier signal FM + when gated and receiving a modulation signal FM-output after the electromagnetic pen modulates its own touch signal, or receiving a coordinate signal fed back by the electromagnetic pen when gated.

Specifically, when the gated X-axis coil 60 is switched to the carrier module 40, the gated Y-axis coil 70 is synchronously switched to the coordinate module 50 — at this time, the gated X-axis coil 60 is used to transmit the carrier signal FM + and receive the modulation signal FM-, and the gated Y-axis coil 70 receives the coordinate signal.

When the gated Y-axis coil 70 is switched to the carrier module 40, the gated X-axis coil 60 is synchronously switched to the coordinate module 50 — at this time, the gated Y-axis coil 70 is used to transmit the carrier signal FM + and receive the modulation signal FM-, and the gated X-axis coil 60 receives the coordinate signal.

at any moment, the gated X-axis coil 60 and the gated Y-axis coil 70 work in a division and cooperation mode, one side transmits the carrier signal FM +, the other side receives the coordinate signal, therefore, the touch sensing device can achieve uninterrupted transmission of the carrier signal FM + and uninterrupted reception of the coordinate signal, the electromagnetic pen in the coverage range of the carrier signal FM + can continuously receive the carrier signal FM +, uninterrupted charging and energy storage are carried out, meanwhile, the modulation signal FM-is fed back uninterruptedly, the signal processing efficiency is high, the signal receiving real-time performance is high, and the accuracy is high. The modulation signal FM-is a signal formed by modulating the touch signal of the electromagnetic pen and the received carrier signal FM +.

Optionally, the touch signal includes pressure information and/or key information of the electromagnetic pen. Specifically, the electromagnetic handwriting board is provided with a display panel, the display panel serves as an operation platform of the electromagnetic pen, a user can hold the electromagnetic pen to operate the electromagnetic pen, a human-computer interaction key is displayed on the display panel, the user can touch the corresponding human-computer interaction key through the electromagnetic pen according to actual needs, and the electromagnetic pen can generate a touch signal containing key information. In addition, the display panel can also be used as a handwriting input platform, a user holds an electromagnetic pen to write or draw on the electromagnetic pen, and the touch signals generated by the electromagnetic pen correspondingly contain pressure-sensitive information. The touch signal may include both the pressure information and the key information, or may include only one of the pressure information and the key information.

The gating module 30 gates a plurality of X-axis coils 60 and a plurality of Y-axis coils 70 one by one according to a preset sequence according to the gating signal, and the gating module 30 gates only one X-axis coil and one Y-axis coil 70 in each period of the gating signal

specifically, at any instant, one X-axis coil 60 and one Y-axis coil 70 are both turned on, and the X-axis coil 60 and the Y-axis coil 70 are only operated when turned on, and are not operated otherwise, and at any instant, only one X-axis coil 60 and one Y-axis coil 70 are in operation. When the gated X-axis coil 60 is switched to the carrier module 40, the gated Y-axis coil 70 is synchronously switched to the coordinate module 50; when the gated Y-axis coil 70 is switched to the carrier module 40, the gated X-axis coil 60 is synchronously switched to the coordinate module 50.

the preset sequence of the plurality of X-axis coils 60 and the plurality of Y-axis coils 70 being gated does not affect the working efficiency of the entire touch sensing device. The coordinate signals include an X-axis coordinate signal received by the X-axis coil 60 and a Y-axis coordinate signal received by the Y-axis coil 70.

The plurality of X-axis coils 60 include an X1 axis coil, an X2 axis coil … … Xn-1 axis coil, and an Xn axis coil; the plurality of Y-axis coils 70 include a Y1 axis coil, a Y2 axis coil … … Ym-1 axis coil, and a Ym axis coil.

For example, assuming that the electromagnetic pen touches (X2, Y6) of the display panel at a certain time, after the gating module 30 gates all the X-axis coils 60 and all the Y-axis coils 70 one by one, the X-axis coordinate signal received by the X2 axis coil is the largest among the multiple X-axis coordinate signals received by the multiple X-axis coils 60, and the Y-axis coordinate signal received by the Y6 axis coil is the largest among the multiple Y-axis coordinate signals received by the multiple Y-axis coils 70, so that after one round of gating, the position touched by the electromagnetic pen on the display panel at the time can be preliminarily determined to be (X2, Y6) point.

In order to accurately acquire the touch position information of the electromagnetic pen and minimize the error, after preliminarily determining that the position touched by the electromagnetic pen on the display panel at this time is the (X2, Y6) point, the gating module 30 again gates the X axis coils X0, X1, X2, X3, X4 and the Y axis coils Y4, Y5, Y6, Y7, Y8, i.e., again scans the coil X2 and a plurality of X axis coils adjacent to the coil X2, and again scans the coil Y6 and a plurality of Y axis coils adjacent to the coil Y6, and accurately calculates and recalibrates the position touched by the electromagnetic pen on the display panel through a software algorithm.

the carrier module 40 is configured to convert the received excitation signal into a carrier signal FM +, perform signal processing on the received modulation signal FM —, and output a touch signal.

Specifically, the excitation signal 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 is resonated after being subjected to push-pull amplification by the carrier module 40, and an alternating electromagnetic field appears in the space, that is, a carrier signal FM + is generated and radiated to the space. The electromagnetic pen in the coverage range of the carrier signal FM + is triggered to charge and store energy after sensing an alternating electromagnetic field in the space, and radiates a modulation signal FM-outwards after modulating a touch signal of the electromagnetic pen into the carrier signal FM +.

The carrier module 40 demodulates, filters, and shapes the modulation signal FM —, and then restores the touch signal on the modulated and carrier signal FM +, and transmits the touch signal to the main control module 10, and the main control module 10 further demodulates the touch signal.

the coordinate module 50 is configured to perform signal processing on the received coordinate signal and output an optimized coordinate signal.

Optionally, the coordinate module 50 performs filtering, multi-stage amplification and integration on the plurality of coordinate signals, and outputs the coordinate signals to the main control module 10.

the switching module 20 is configured to communicate the gated X-axis coil 60 with the carrier module 40 and communicate the gated Y-axis coil 70 with the coordinate module 50 when receiving the first switching signal, or communicate the gated X-axis coil 60 with the coordinate module 50 and communicate the gated Y-axis coil 70 with the carrier module 40 when receiving the second switching signal.

Specifically, the carrier module 40 and the coordinate module 50 are both connected to the switching module 20, the switching module 20 is connected to the plurality of X-axis coils 60 and the plurality of Y-axis coils 70, and when the X-axis coil 60 gated by the gating module 30 is switched to the carrier module 40 by the switching module 20, that is, the gated X-axis coil 60 is connected to the carrier module 40, the gated X-axis coil 60 transmits a carrier signal FM + and receives a modulation signal FM-; meanwhile, the Y-axis coil 70 gated by the gating module 30 is synchronously switched to the coordinate module 50 by the switching module 20, and the gated Y-axis coil 70 receives the Y-axis coordinate signal.

When the Y-axis coil 70 gated by the gating module 30 is switched to the carrier module 40 by the switching module 20, that is, the gated Y-axis coil 70 is connected to the carrier module 40, the gated Y-axis coil 70 transmits a carrier signal FM + and receives a modulation signal FM-; meanwhile, the X-axis coil 60 gated by the gating module 30 is synchronously switched to the coordinate module 50 by the switching module 20, and the gated X-axis coil 60 receives the X-axis coordinate signal.

The switching module 20 switches the X-axis coil 60 to the carrier module 40 or the coordinate module 50, and synchronously switches the Y-axis coil 70 to the coordinate module 50 or the carrier module 40, thereby realizing uninterrupted transmission of a carrier signal FM +, uninterrupted reception of a modulation signal FM-and uninterrupted reception of a coordinate signal, with strong real-time and high signal processing efficiency.

The first switching signal and the second switching signal are opposite phase signals.

the main control module 10 is configured to output a gating signal, a first switching signal, and a second switching signal, receive a touch signal and an optimized coordinate signal, and calibrate the X-axis coil 60 and the Y-axis coil 70 that receive the maximum value of the coordinate signal to determine the touch position of the electromagnetic pen, and the main control module 10 is further configured to upload the touch signal and information of the touch position.

For example, if the electromagnetic pen touches the (X2, Y6) point of the display panel at a certain time, the X2 axis coil receives the maximum value of the X2 axis coordinate signals among a plurality of X axis coordinate signals obtained after all the X axis coils 60 and all the Y axis coils 70 are gated in one round; among the obtained multiple Y-axis coordinate signals, the Y6 axis coil receives the largest value of the Y6 axis coordinate signal, so that the position where the electromagnetic pen touches the display panel at that moment can be preliminarily determined to be (X2, Y6) points, and the main control module 10 calibrates the X2 axis coil and the Y6 axis coil.

specifically, the main control module 10 uploads the touch signal and the information of the touch position to the upper computer of the electromagnetic handwriting board, and the upper computer controls the electromagnetic handwriting board according to the touch signal and the information of the touch position, so that the electromagnetic handwriting board displays a sliding track of the electromagnetic pen or executes a function corresponding to a touched key. 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 a unit structure of the touch sensing device shown in fig. 1, which only shows parts related to the present embodiment for convenience of description, and the details are as follows:

In an alternative embodiment, the carrier module 40 includes a push-pull unit 401, a resonance unit 402, a demodulation unit 403, a filtering unit 404, and a shaping unit 405.

The push-pull unit 401 is connected with the main control module 10, the resonance unit 402 is connected with the push-pull unit 401 and is connected with the X-axis coil 60 and the Y-axis coil 70 through the gating module 30, the demodulation unit 403 is connected with the X-axis coil 60 and the Y-axis coil 70 through the gating module 30, the filtering unit 404 is connected with the demodulation unit 403, and the shaping unit 405 is connected with the filtering unit 404 and the main control module 10.

The push-pull unit 401 is configured to amplify the excitation signal and output the amplified excitation signal to the resonance unit 402. The resonance unit 402 is configured to convert the amplified excitation signal into a carrier signal FM +.

specifically, the resonance unit 402 establishes a connection with the X-axis coil 60 and the Y-axis coil 70 through the gating module 30, and forms a capacitance-inductance series resonance circuit with the gated X-axis coil 60 or the gated Y-axis coil 70, and an excitation signal flowing through the capacitance-inductance series resonance circuit resonates and is emitted outward by the gated X-axis coil 60 or the gated Y-axis coil 70 in the form of a carrier signal FM +.

the demodulation unit 403 is used to demodulate the modulated signal FM-and output a demodulated signal.

specifically, the X-axis coil 60 or the Y-axis coil 70, which is gated and switched to the carrier module 40, outputs the received modulated signal FM-to the demodulation unit 403, which is demodulated by the demodulation unit 403 and outputs a demodulated signal to the filtering unit 404.

the filtering unit 404 is configured to filter the demodulated signal and output a demodulated filtered signal. Specifically, the filtering unit 404 filters out the dc interference signal in the demodulated signal.

The shaping unit 405 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.

when the gated X-axis coil 60 is switched to the carrier module 40 by the switching module 20, the X-axis coil 60 transmits a carrier signal FM + and receives a modulation signal FM-. When the gated Y-axis coil is switched by the switching module 20 to the carrier module 40, the Y-axis coil 70 transmits a carrier signal FM + and receives a modulation signal FM-. At any time when the touch sensing device is operating, there is one and only one gated coil (X-axis coil 60 or Y-axis coil 70) in communication with the carrier module 40 through the switching module 20.

In an alternative embodiment, the gating module 30 includes at least one first switching unit 301 and at least one second switching unit 302.

The first switch unit 301 is connected in series between the switching module 20 and the predetermined number of X-axis coils 60, and the second switch unit 302 is connected in series between the switching module 20 and the predetermined number of Y-axis coils 70.

The first switching unit 301 is configured to gate the internal analog switch when receiving the gate signal, so as to operate the corresponding X-axis coil 60.

The second switching unit 302 is used for correspondingly gating the internal analog switch when receiving the gating signal so as to enable the corresponding Y-axis coil 70 to work.

Specifically, when the analog switch inside the first switching unit 301 is turned on, the X-axis coil 60 connected in series with the analog switch operates, that is, the X-axis coil 60 is turned on. The gated X-axis coil 60, when switched to the carrier module 40, is used to transmit a carrier signal FM + and receive a modulated signal FM-; the gated X-axis coil 60 is switched to the coordinate module 50 for receiving X-axis coordinate signals.

When the analog switch inside the second switching unit 302 is turned on, the Y-axis coil 70 connected in series with the analog switch operates, that is, the Y-axis coil 70 is turned on. The gated Y-axis coil 70, when switched to the carrier module 40, is used to transmit a carrier signal FM + and receive a modulated signal FM-; the gated Y-axis coil 70 is switched to the coordinate module 50 for receiving the Y-axis coordinate signal.

The first switch unit 301 gates an X-axis coil 60, the second switch unit 302 gates a Y-axis coil 70, and at any time, only one X-axis coil 60 and one Y-axis coil 70 are gated, and the gated X-axis coil 60 and Y-axis coil 70 are correspondingly connected to the carrier module 40 or the coordinate module 50 according to the control of the switch module 20, so as to complete the transmission process of the carrier signal FM + and the reception process of the modulation signal FM-and complete the reception process of the coordinate signal at the same time.

Specifically, the first switch unit 301 includes eight analog switches, one end of each analog switch is connected to one end of one X-axis coil 60, the other ends of all the analog switches are connected in common, and the common connection point is connected to the switching module 20 as a common end of the first switch unit 301, when a certain analog switch is turned on, the X-axis coil 60 connected to the analog switch is turned on, thereby performing operation; the second switching unit 302 includes eight analog switches, one end of each analog switch is connected to one end of one Y-axis coil 70, the other ends of all the analog switches are connected in common, and the common connection point is connected to the switching module 20 as a common end of the second switching unit 302, and when an analog switch is turned on, the Y-axis coil 70 connected to the analog switch is turned on, thereby performing an operation.

fig. 3 is a schematic diagram of wiring of a coil in the touch sensing device shown in fig. 1, and for convenience of description, only the portions related to the present embodiment are shown, and detailed descriptions are as follows:

optionally, the plurality of X-axis coils 60 are perpendicular to the plurality of Y-axis coils 70, and a plane where the plurality of X-axis coils 60 and the plurality of Y-axis coils 70 are located is parallel to a plane where the electromagnetic handwriting board is located, specifically, parallel to a plane where the display panel is located. The touch control induction device provided by the invention is arranged in the electromagnetic handwriting board.

one ends of the plurality of X-axis coils 60 are connected in common, and the common connection point X + is connected to the switching module 20; the other ends of the plurality of X-axis coils 60 are connected to the first switch unit 301, specifically, connected to the analog switches inside the first switch unit 301, respectively, one end of all the analog switches of the first switch unit 301 is connected in common, and the common connection point X-is connected to the switching module 20. When a certain X-axis coil 60 is gated, the X-axis coil 60 communicates with the switching module 20 via the X + point and the X-point, thereby communicating with the carrier module 40 or the coordinate module 50.

One ends of the plurality of Y-axis coils 70 are connected in common, and the common connection point Y + is connected to the switching module 20; the other ends of the Y-axis coils 70 are connected to the second switch unit 302, specifically, connected to the analog switches inside the second switch unit 302, respectively, one ends of all the analog switches of the second switch unit 302 are connected in common, and the common connection point Y-is connected to the switching module 20. When a certain Y-axis coil 70 is gated, the Y-axis coil 70 communicates with the switching module 20 via the Y + point and the Y-point, thereby communicating with the carrier module 40 or the coordinate module 50.

At any time, there are two states of communication:

First, there is an X-axis coil 60 connected to the switching module 20 via X + and X-points to connect to the carrier module 40, and a Y-axis coil 70 connected to the switching module 20 via Y + and Y-points to connect to the coordinate module 50;

second, there is a Y-axis coil 70 connected to the switching module 20 via Y + and Y-points to connect to the carrier module 40, while there is an X-axis coil 60 connected to the switching module 20 via X + and X-points to connect to the coordinate module 50.

Through the cooperation of the X-axis coil 60 and the Y-axis coil 70, the touch sensing device continuously transmits the carrier signal FM + and receives the modulation signal FM-and simultaneously continuously receives the coordinate signal, so that the problems of low signal processing efficiency and high processing difficulty due to the fact that the time length of the received signal and the time length of the transmitted signal are limited by adopting a time-sharing signal receiving and transmitting method are solved.

Fig. 4 is a schematic circuit diagram of an example of the carrier module 40 in the touch sensing device shown in fig. 3, which only shows the relevant parts related to the present embodiment for convenience of description, and the details are as follows:

the carrier module 40 includes a push-pull unit 401, a resonance unit 402, a demodulation unit 403, a filtering unit 404, and a shaping unit 405.

The push-pull unit 401 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 resonant cell 402 includes a capacitor C8, a capacitor C9, and a capacitor C10.

The demodulation unit 403 includes a diode D2, a capacitor C6, and a resistor R7.

the filtering unit 404302 includes a capacitor C7.

The shaping unit 405303 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 transistor Q4.

the first end of the capacitor C5 is connected to the main control module 10 to receive the excitation signal output by the main control module 10, and the excitation signal 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 X-axis coil 60 or the first end of the Y-axis coil 70, the second end of the X-axis coil 60 or the second end of the Y-axis coil 70, 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.

it should be noted that the X-axis coil 60 and the Y-axis coil 70 are communicated with the carrier module 40 or the coordinate module 50 through the gating module 30 and the switching module 20, the X-axis coil 60 or the Y-axis coil 70 shown in fig. 4 is gated by the gating module 30 and switched to the carrier module 40 by the switching module 20, and the X-axis coil 60 or the Y-axis coil 70 shown in fig. 4 is only used to assist in explaining the working principle of the carrier module 40 in this embodiment.

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 is amplified by the push-pull circuit and then output to the resonance unit 402201. The resonance unit 402201 and the gated X-axis coil 60 or Y-axis coil 70 form an inductor-capacitor series resonance circuit, and the excitation signal output after being amplified by push-pull generates resonance through the resonance unit 402, so as to generate a sine wave signal, so that an alternating electromagnetic field appears in the space, and an electromagnetic pen in the coverage range of the carrier signal FM + is triggered after receiving the carrier signal FM +, and charges, stores energy, and feeds back a modulation signal FM-.

The anode of the diode D2 is connected to the X-axis coil 60 or the Y-axis coil 70 to receive the modulation signal FM sensed by the X-axis coil 60 or the Y-axis coil 70, the cathode of the diode D2, the first terminal of the capacitor C6, and the first terminal of the resistor R7 are connected in common, 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 modulated signal FM —, and the recovered touch signal is transmitted to the main control module 10 in the form of a DATA stream DATA.

fig. 5 is a schematic circuit diagram of an example of the coordinate module 50 in the touch sensing device shown in fig. 2, which only shows the relevant parts related to the present embodiment for convenience of description, and the details are as follows:

Coordinate module 50 includes a resistor R28, a resistor R29, a capacitor C29, an amplifier U29-a, an amplifier U29-B, an amplifier U29-C, an amplifier U29-D, an amplifier U29-29 a, an NPN diode-n-channel Q amplifier, an NPN diode.

A first end of the capacitor C43 is connected to the switching module 20 for receiving the coordinate signal, a second end of the capacitor C43, a first end 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 end of the resistor R28 and a first end 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 is commonly connected with the first end of the resistor R35, the first end of the resistor R46 and the drain of the N-channel FET Q5, the second end of the resistor R35, the source of the N-channel FET Q5 and the first end of the resistor R34,

The gate of the N-channel fet Q5, the second terminal of the resistor R46, and the first terminal of the resistor R45 are connected together, and the second terminal of the resistor R45 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 1010. 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 1010.

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 is connected to the switching module 20 as a first input terminal PEN _ X _ Y + of the coordinate module 50, and a second terminal of the resistor R29 is connected to the switching module 20 as a second input terminal PEN _ X _ Y-of the coordinate module 50. When the gated X-axis coil 60 or the gated Y-axis coil 70 is switched to the coordinate module 50 by the switching module 20, both ends of the X-axis coil 60 or the Y-axis coil 70 communicate with the coordinate module 50 through the switching module 20 and the gating module 30, and the received X-axis coordinate signal and Y-axis coordinate signal are transmitted to the coordinate module 50. After the input coordinate signal is processed by the circuit of the coordinate signal processing unit through the multi-stage operational amplifier, the filtering process and the integration process, the optimized coordinate signal is output to the analog-to-digital conversion interface of the main control module 10, namely the POS _ AD port, the voltage value of the coordinate signal is obtained by the main control module 10 and compared, and the X-axis coil 60 corresponding to the maximum value of the X-axis coordinate signal and the Y-axis coil 70 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 received by the X-axis coil 60 or the Y-axis coil 70; 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 module 50 finishes processing one coordinate signal, the integrating capacitor in the circuit is emptied before processing the next coordinate signal.

Fig. 6 and 7 are schematic circuit diagrams of an example of a first switch unit 301 and a second switch unit 302 in the touch sensing device shown in fig. 2, respectively, and for convenience of description, only the parts related to the present embodiment are shown, and detailed descriptions are as follows:

The first switch unit 301 is connected in series between the switching module 20 and the predetermined number of X-axis coils 60, and the second switch unit 302 is connected in series between the switching module 20 and the predetermined number of Y-axis coils 70.

The first switching unit 301 is configured to gate the internal analog switch when receiving the gate signal, so as to operate the corresponding X-axis coil 60.

The second switching unit 302 is used for correspondingly gating the internal analog switch when receiving the gating signal so as to enable the corresponding Y-axis coil 70 to work.

When the analog switch inside the first switching unit 301 is turned on, the X-axis coil 60 connected in series with the analog switch operates. The gated X-axis coil 60, when switched to the carrier module 40, is used to transmit a carrier signal FM + and receive a modulated signal FM-; the gated X-axis coil 60 is switched to the coordinate module 50 for receiving X-axis coordinate signals.

when the analog switch inside the second switching unit 302 is turned on, the Y-axis coil 70 connected in series with the analog switch operates. The gated Y-axis coil 70, when switched to the carrier module 40, is used to transmit a carrier signal FM + and receive a modulated signal FM-; the gated Y-axis coil 70 is switched to the coordinate module 50 for receiving the Y-axis coordinate signal.

the first switch unit 301 gates an X-axis coil 60, the second switch unit 302 gates a Y-axis coil 70, and at any time, only one X-axis coil 60 and one Y-axis coil 70 are gated, and the gated X-axis coil 60 and Y-axis coil 70 are correspondingly connected to the carrier module 40 or the coordinate module 50 according to the control of the switch module 20, so as to complete the transmission process of the carrier signal FM + and the reception process of the modulation signal FM-and complete the reception process of the coordinate signal at the same time.

optionally, each of the first switch unit 301 and the second switch unit 302 is implemented by an 8-to-1 data selector, each of the 8-to-1 data selectors includes 8 analog switches, and the corresponding analog switches are gated according to the received 4-way gating signal (INH, C, B, a). The main control module 10 outputs a 4-way gate signal to the first switch unit 301 or the second switch unit 302, thereby controlling the operating state of the analog switch.

At any time, the first switching unit 301 has an analog switch turned on and the X-axis coil 60 corresponding thereto operates, and the second switching unit 302 has an analog switch turned on and the Y-axis coil 70 corresponding thereto operates.

fig. 8 is a schematic circuit diagram of an example of the switching module 20 in the touch sensing device shown in fig. 2, which only shows the relevant parts related to the present embodiment for convenience of description, and the detailed description is as follows:

In an alternative embodiment, the switching module 20 includes a four-channel single pole double throw switch U20 and an inverter U21.

The four-channel single-pole double-throw switch U20 includes a first normally closed terminal NC1, a second normally closed terminal NC2, a third normally closed terminal NC3, a fourth normally closed terminal NC4, a first normally open terminal NO1, a second normally open terminal NO2, a third normally open terminal NO3, a fourth normally open terminal NO4, a first controlled terminal IN1-2, a second controlled terminal IN3-4, a first common terminal COM1, a second common terminal COM2, a third common terminal COM3, and a fourth common terminal COM 4.

the first normally closed end NC1 and the third normally closed end NC3 are connected together and then are connected into the coordinate module 50, and the second normally closed end NC2 and the third normally closed end NC3 are connected together and then are connected into the coordinate module 50; the first normally open end NO1 and the third normally open end NO3 are connected together and then connected to the carrier module 40, and the second normally open end NO2 and the fourth normally open end NO4 are connected together and then connected to the carrier module 40.

the first common terminal COM1 is connected to one ends of the plurality of X-axis coils 60, and the second common terminal COM2 is connected to the other ends of the plurality of X-axis coils 60; the third common terminal COM3 is connected to one ends of the plurality of Y-axis coils 70, and the fourth common terminal COM4 is connected to the other ends of the plurality of Y-axis coils 70.

The first controlled terminal IN1-2 is connected to the master control module 10 after being connected to the input terminal of the inverter U21, and the second controlled terminal IN3-4 is connected to the output terminal of the inverter U21.

Specifically, the master control module 10 outputs a first switching signal or a second switching signal (collectively, the switching signal SW _ TX _ RX is output to the first controlled terminal IN1-2 of the four-channel single-pole double-throw switch U20, and the switching signal SW _ TX _ RX is inverted by the inverter U21 and then output to the second controlled terminal IN3-4 of the four-channel single-pole double-throw switch U20.

When the main control module 10 outputs the first switching signal, the gated X-axis coil 60 is connected to the carrier module 40 through the switching module 20, and the gated Y-axis coil 70 is connected to the coordinate module 50 through the switching module 20. At this time, the common point X + is connected to the first normally open end NO1 through the first common terminal COM1, and the common point X-is connected to the second normally open end NO2 through the second common terminal COM 2; the common node Y + is connected to the third normally closed terminal NC3 through the third common terminal COM3, and the common node Y-is connected to the fourth normally closed terminal NC4 through the fourth common terminal COM 4.

When the main control module 10 outputs the second switching signal, the gated X-axis coil 60 is connected to the coordinate module 50 through the switching module 20, and the gated Y-axis coil 70 is connected to the carrier module 40 through the switching module 20. At this time, the common node X + is connected to the first normally closed terminal NC1 through the first common terminal COM1, and the common node X-is connected to the second normally closed terminal NC2 through the second common terminal COM 2; the common point Y + is connected to the third normally-open end NO3 through the third common terminal COM3, and the common point Y-is connected to the fourth normally-open end NO4 through the fourth common terminal COM 4.

Optionally, the second switching signal is a low level signal.

Optionally, the first switching signal is a high level signal.

The working principle of the touch sensing device is specifically described as follows:

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, which is specifically a low-frequency PWM square wave signal. After the excitation signal is amplified in a push-pull mode, the inductance-capacitance series resonance circuit is driven, and a low-frequency carrier signal FM + is transmitted through the X-axis coil 60 or the Y-axis coil 70 to generate an alternating electromagnetic field in space. The electromagnetic pen in 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 modulates the touch signal on a carrier signal FM + to form a modulation signal FM-, scatters the modulation signal FM-outwards, and receives the modulation signal FM-by the X-axis coil 60 or the Y-axis coil 70. And the touch signal is restored after the modulation signal FM-is demodulated, filtered and subjected to waveform shaping. 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 first switch unit 301 and the second switch unit 302 to gate one by one, so as to switch the X-axis coil 60 and the Y-axis coil 70 respectively connected to the analog switches in series at a high speed. The gated X-axis coil 60 and Y-axis coil 70 receive the coordinate signal fed back by the electromagnetic pen on the one hand, and transmit the carrier signal FM + and receive the modulation signal FM-. The electromagnetic field at the position touched by the pen point of the electromagnetic pen is strongest, and the values of the X-axis coordinate signal and the Y-axis coordinate signal received by the X-axis coil 60 and the Y-axis coil 70 corresponding to the electromagnetic pen are the largest, for example, the pen point of the electromagnetic pen touches the point (X3, Y5) of the handwriting pad of the electromagnetic pen, the value of the X-axis coordinate signal received by the X3-axis coil is the largest among the values of the respective X-axis coordinate signals received by all the X-axis coils 60, and the value of the Y-axis coordinate signal received by the Y5-axis coil is the largest among the values of the respective Y-axis coordinate signals received by all the Y-axis coils 70.

Each coordinate 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, processes all the voltage values by a bubble program method, and calibrates an X-axis coil 60 (hereinafter, Xmax denotes the X-axis coil 60) corresponding to an X-axis coordinate signal having a maximum voltage value and a Y-axis coil 70 (hereinafter, Ymax denotes the Y-axis coil 70) corresponding to a Y-axis coordinate signal having a maximum voltage value, thereby preliminarily determining a touch position of the electromagnetic pen 200, that is, (Xmax, Ymax).

the main control module 10 outputs a first switching signal or a second switching signal to the four-channel single-pole double-throw switch U20, switches the X (Y) axis coil to the carrier module 40, and synchronously switches the Y (X) axis direction coil to the coordinate. The main control module 10 controls the gating module 30 to gate the X-axis coil 60 and the Y-axis coil 70 one by one.

The main control module 10 further uploads the touch signal and the touch position information of the electromagnetic pen to the 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.

fig. 9 is a specific flowchart of a touch sensing method for an electromagnetic writing pad according to a second aspect of the embodiment of the present invention, which only shows parts related to the embodiment for convenience of description, and the detailed description is as follows:

A touch sensing method for an electromagnetic writing pad comprises the following steps:

s01: the main control module 10 is adopted to output gating signals, first switching signals or second switching signals;

s02: the gating module 30 is adopted to gate a plurality of X-axis coils 60 and a plurality of Y-axis coils 70 one by one according to a preset sequence according to the gating signal, and only one X-axis coil and one Y-axis coil 70 are gated in each period of the gating signal;

s03: when the switching module 20 is adopted to receive the first switching signal, the gated X-axis coil 60 is switched to the carrier module 40, and the gated Y-axis coil 70 is switched to the coordinate module 50;

S04: when the switching module 20 is adopted to receive the second switching signal, the gated Y-axis coil 70 is switched to the carrier module 40, and the gated X-axis coil 60 is switched to the coordinate module 50;

S05: when the X-axis coil 60 is switched to the carrier module 40 and the Y-axis coil 70 is switched to the coordinate module 50, the X-axis coil 60 is used to transmit a carrier signal FM + and receive a modulation signal FM —, which is output after the electromagnetic pen modulates its own touch signal, and the Y-axis coil 70 is used to receive a coordinate signal fed back by the electromagnetic pen;

S06: when the X-axis coil 60 is switched to the coordinate module 50 and the Y-axis coil 70 is switched to the carrier module 40, the Y-axis coil 70 is used to transmit the carrier signal FM + and receive the modulation signal FM-, and the X-axis coil 60 is used to receive the coordinate signal;

s07: the carrier module 40 is adopted to convert the received excitation signal into a carrier signal FM + for the X-axis coil 60 or the Y-axis coil 70 to transmit, and output a touch signal to the main control module 10 after performing signal processing on a modulation signal FM —, which is received by the X-axis coil 60 or the Y-axis coil 70;

S08: the coordinate module 50 is adopted to perform signal processing on the coordinate signal and then output an optimized coordinate signal to the main control module 10;

s09: calibrating the X-axis coil 60 and the Y-axis coil 70 which receive the maximum value of the coordinate signal by adopting the main control module 10 to determine the touch position of the electromagnetic pen, and uploading the touch signal and the information of the touch position;

The following describes the principle 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, which is specifically a low-frequency PWM square wave signal. After the excitation signal is amplified in a push-pull mode, the inductance-capacitance series resonance circuit is driven, and a low-frequency carrier signal FM + is transmitted through the X-axis coil 60 or the Y-axis coil 70 to generate an alternating electromagnetic field in space. The electromagnetic pen in 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 modulates the touch signal on a carrier signal FM + to form a modulation signal FM-, scatters the modulation signal FM-outwards, and receives the modulation signal FM-by the X-axis coil 60 or the Y-axis coil 70. And the touch signal is restored after the modulation signal FM-is demodulated, filtered and subjected to waveform shaping. 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 first switch unit 301 and the second switch unit 302 to gate one by one, so as to switch the X-axis coil 60 and the Y-axis coil 70 respectively connected to the analog switches in series at a high speed. The gated X-axis coil 60 and Y-axis coil 70 receive the coordinate signal fed back by the electromagnetic pen on the one hand, and transmit the carrier signal FM + and receive the modulation signal FM-. The electromagnetic field at the position touched by the pen point of the electromagnetic pen is strongest, and the values of the X-axis coordinate signal and the Y-axis coordinate signal received by the X-axis coil 60 and the Y-axis coil 70 corresponding to the electromagnetic pen are the largest, for example, the pen point of the electromagnetic pen touches the point (X3, Y5) of the handwriting pad of the electromagnetic pen, the value of the X-axis coordinate signal received by the X3-axis coil is the largest among the values of the respective X-axis coordinate signals received by all the X-axis coils 60, and the value of the Y-axis coordinate signal received by the Y5-axis coil is the largest among the values of the respective Y-axis coordinate signals received by all the Y-axis coils 70.

Each coordinate 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 obtained coordinate signals, and processes all the voltage values by a bubble program method to calibrate Xmax corresponding to the X-axis coordinate signal having the largest voltage value and Ymax corresponding to the Y-axis coordinate signal having the largest voltage value, thereby preliminarily determining the touch position of the electromagnetic pen 200, i.e., (Xmax, Ymax).

the main control module 10 outputs a first switching signal or a second switching signal to the four-channel single-pole double-throw switch U20, switches the X (Y) axis coil to the carrier module 40, and synchronously switches the Y (X) axis direction coil to the coordinate. The main control module 10 controls the gating module 30 to gate the X-axis coil 60 and the Y-axis coil 70 one by one.

The main control module 10 further uploads the touch signal and the touch position information of the electromagnetic pen to the 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 S02 and before step S09, the method further includes step S10:

And sequentially gating the plurality of X-axis coils 60 adjacent to the calibrated X-axis coil 60 and the plurality of Y-axis coils 70 adjacent to the calibrated Y-axis coil 70 according to a second preset sequence by using the gating module 30 according to a second gating signal, so that the plurality of secondarily gated X-axis coils 60 and the plurality of secondarily gated Y-axis coils 70 respectively receive the coordinate signals again.

In an alternative embodiment, before step S10, the method further includes step S11: the main control module 10 is adopted to output a second gating signal to the gating module 30.

Since the touch position of the electromagnetic pen needs to be sequentially gated by all the X-axis coils 60 and the Y-axis coils 70, a signal reception delay is caused during scanning, and an error inevitably exists.

in order to more accurately acquire the touch position information of the electromagnetic pen and minimize the error, the main control module 10 outputs a second gating signal to the gating module 30 after preliminarily determining the touch position of the electromagnetic pen, i.e., after calibrating the (Xmax, Ymax) coil combination, so that a plurality of X-axis coils 60 (e.g., Xmax-2, Xmax-1, Xmax +2) adjacent to Xmax and a plurality of Y-axis coils 70 (e.g., Ymax-2, Ymax-1, Ymax +2) adjacent to Ymax are secondarily gated, the secondarily gated coils are sequentially gated, and receive coordinate signals one by one, which are processed by the coordinate module 50 and output to the main control module 10, and the main control module 10 determines the voltage value and calibrates the coil of the X-axis coils 60Xmax-2, Xmax-1, Xmax +1, Xmax +2 that receives the maximum value of the X-axis coordinate signals, similarly, the coil of the Y-axis coils 70Ymax-2, Ymax-1, Ymax +1, and Ymax +2 that receives the maximum value of the Y-axis coordinate signal is calibrated.

For example, the coil combination of the secondary calibration is (Xmax, Ymax +2), which is more accurate in position than the coil combination 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 embodiment of the present invention provides a touch sensing apparatus and method for an electromagnetic handwriting pad, in which an X-axis coil is switched to a carrier module and a Y-axis coil 70 is synchronously switched to a coordinate module through a switching module, or the Y-axis coil 70 is switched to the carrier module and the X-axis coil is synchronously switched to the coordinate module; the gating module gates the plurality of X-axis coils and the plurality of Y-axis coils 70 one by one according to a preset sequence, so that when the X-axis coils transmit carrier signals and receive modulation signals fed back by the electromagnetic pen, the Y-axis coils 70 receive coordinate signals; when the Y-axis coil 70 transmits a carrier signal and receives a modulation signal fed back by the electromagnetic pen, the X-axis coil receives a coordinate signal. Therefore, uninterrupted transmission of the carrier signal to the electromagnetic pen is guaranteed, synchronous transmission of the carrier signal and synchronous reception of the coordinate signal are achieved, the time length for receiving and transmitting the signal is not limited, the electromagnetic pen is charged wirelessly and is subjected to uninterrupted energy storage, the real-time performance for receiving the coordinate signal is high, the delay effect is reduced, and the precision is high; and the carrier module processes the modulation signal, and the coordinate module processes the coordinate signal, so that the signal processing efficiency is high.

Various embodiments are described herein for various circuits, devices, or 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.

Each functional unit in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

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.