Electromagnetic touch sensing apparatus, screen assembly, electronic device, and touch system

Abstract

Embodiments of the present application disclose an electromagnetic touch sensing apparatus, a screen assembly, an electronic device, and a touch system. An electromagnetic touch screen comprises multiple electrodes extending along a first direction, and at least two electrodes are coupled by means of an impedance module, so that a loop is formed between the two coupled electrodes. Then, a voltage sampling module is used to collect a voltage on the impedance module, to obtain a voltage signal that reflects a magnitude of a current in the loop of the two electrodes. Because current directions in sensing coils are the same, a direction of the voltage on the impedance module between the two electrodes is determined. Therefore, the position of an electromagnetic pen can be indicated by the position of the maximum voltage value. In contrast to a sampling method that directly performs current sampling, which leads to opposite current directions on electrodes reused by adjacent sensing coils, and thus prevents the position of the electromagnetic pen from being determined on the basis of the position of the maximum current signal, embodiments of the present application can accurately determine the position of the electromagnetic pen by means of a voltage sampling signal from the voltage sampling module.

Description

Electromagnetic touch sensing devices, screen assemblies, electronic devices and touch systems Technical Field

[0001] This application relates to the field of touch technology, and in particular to an electromagnetic touch sensing device, screen assembly, electronic device and touch system. Background Technology

[0002] Currently, electromagnetic touchscreens using EMR (Electro Magnetic Resonance) technology have multiple independent coils. These coils are divided into drive coils and sensing coils. The drive coil is connected to the touchscreen chip to receive drive signals. The coil induces a changing magnetic field on the surface of the electromagnetic touchscreen. When the electromagnetic pen approaches the electromagnetic touchscreen, the coil in the electromagnetic pen induces a current due to the magnetic field on the surface of the electromagnetic touchscreen. The electromagnetic pen stores energy through methods such as capacitor energy storage, and then emits the energy in the form of a magnetic field through an internal oscillation circuit. In this way, the sensing coil of the electromagnetic touchscreen can sense the magnetic field signal emitted by the electromagnetic pen, thereby inducing a current in the sensing coil. The electromagnetic touchscreen then determines the location of the electromagnetic pen by sampling the current envelope signal.

[0003] Besides the aforementioned scheme of independent coils, electromagnetic touchscreens can also form a comb-like structure as shown in Figure 1 by short-circuiting one end of the electrodes that make up the coils together. In the comb-like structure, since adjacent coils share a common terminal, when the electromagnetic pen is positioned above two adjacent coils, the current coupling at the common terminal of the adjacent coils is in opposite directions, as shown in Figure 2. This results in the collected current being either positive, negative, or zero, making the current signal envelope non-monotonic. Consequently, the electromagnetic touchscreen cannot align the position of the electromagnetic pen with the position of the maximum current signal.

[0004] Summary of the Invention

[0005] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0006] This application provides an electromagnetic touch sensing device, a screen assembly, an electronic device, and a touch system, which obtain electromagnetic touch signals by converting them into voltage acquisition, thereby accurately determining the position of the electromagnetic pen.

[0007] On one hand, this application provides an electromagnetic touch sensing device for electromagnetic touch signals, used to couple to an electromagnetic touch screen. The electromagnetic touch screen includes multiple electrodes extending along a first direction, with two adjacent electrodes forming a sensing coil. The electromagnetic touch sensing device senses the changes in the electromagnetic field of each sensing coil caused by an electromagnetic pen on the electromagnetic touch screen to sense the position of the electromagnetic pen. The electromagnetic touch sensing device includes:

[0008] An impedance module for coupling at least two of the electrodes;

[0009] A voltage sampling module is used to sample the voltage on the impedance module.

[0010] In some embodiments, the impedance module is coupled between every two adjacent electrodes.

[0011] In some embodiments, the impedance module is coupled between two non-adjacent electrodes, and a predetermined number of electrodes are spaced between the two non-adjacent electrodes.

[0012] In some embodiments, the impedance module is coupled between two non-adjacent electrodes, and the number of electrodes spaced between the two non-adjacent electrodes is not fixed.

[0013] In some embodiments, the electromagnetic touch screen further includes a plurality of driving coils arranged along a second direction, which is perpendicular to the first direction. Each of the driving coils is driven such that the electromagnetic touch sensing device senses the change in the electromagnetic field of the overlapping portion of each sensing coil and the currently driven driving coil to sense the position of the electromagnetic pen.

[0014] In some embodiments, the electromagnetic touch sensing device further includes a switching device connected in series with the impedance module, wherein, when the switching device is open, the sensing coil is used as the driving coil.

[0015] In some embodiments, the electromagnetic touch sensing device further includes a control module coupled to the output of the voltage sampling module and configured to determine the position of the electromagnetic pen based on the voltage sampling signal output by the voltage sampling module.

[0016] In some embodiments, the impedance module includes a resistor network comprising at least one resistor for coupling the two electrodes.

[0017] In some embodiments, the impedance module further includes a capacitor connected in series or in parallel with any of the resistors.

[0018] In some embodiments, the impedance module has one of the following structures:

[0019] The resistor network includes a first resistor, and the impedance module further includes a first capacitor connected in parallel with the first resistor;

[0020] The resistor network includes a second resistor and a third resistor connected in series, and the impedance module also includes a second capacitor connected in parallel with the second resistor;

[0021] The resistor network includes a fourth resistor and a fifth resistor connected in parallel, and the impedance module also includes a third capacitor connected in series with the fourth resistor.

[0022] In some embodiments, the voltage sampling module includes a first amplifier, a second amplifier, and a third amplifier, wherein,

[0023] The first amplifier amplifies the voltage of one of the two electrodes to generate a first amplified signal;

[0024] The second amplifier amplifies the voltage of the other of the two electrodes to generate a second amplified signal;

[0025] The third amplifier amplifies the differential signal between the first amplified signal and the second amplified signal to obtain a voltage sampling signal.

[0026] In some embodiments, the first amplifier, the second amplifier, and the third amplifier are all fully differential operational amplifiers, wherein...

[0027] The first amplifier has a first differential input terminal, a second differential input terminal, and a first output terminal. The first differential input terminal is coupled to one of the two electrodes, and the second differential input terminal is connected to a reference voltage. The second amplifier has a third differential input terminal, a fourth differential input terminal, and a second output terminal. The third differential input terminal is coupled to the other of the two electrodes, and the fourth differential input terminal is connected to a reference voltage. The third amplifier has a fifth differential input terminal, a sixth differential input terminal, and a third output terminal. The fifth differential input terminal is used to receive the first amplified signal output from the first output terminal, the sixth differential input terminal is used to receive the second amplified signal output from the second output terminal, and the third output terminal is used to output the voltage sampling signal.

[0028] In some embodiments, the first amplifier, the second amplifier, and the third amplifier are all single-ended operational amplifiers, wherein...

[0029] The first amplifier has a first non-inverting input terminal, a first inverting input terminal, and a first output terminal. The first non-inverting input terminal is coupled to one of the two electrodes, and the first inverting input terminal is connected to a reference voltage. The second amplifier has a second non-inverting input terminal, a second inverting input terminal, and a second output terminal. The second non-inverting input terminal is coupled to the other of the two electrodes, and the second inverting input terminal is connected to a reference voltage. The third amplifier has a third non-inverting input terminal, a third inverting input terminal, and a third output terminal. The third non-inverting input terminal is used to receive the first amplified signal output from the first output terminal, the third inverting input terminal is used to receive the second amplified signal output from the second output terminal, and the third output terminal is used to output the voltage sampling signal.

[0030] In some embodiments, the first amplifier, the second amplifier, and the third amplifier are all single-ended operational amplifiers, wherein...

[0031] The first amplifier has a first non-inverting input terminal, a first inverting input terminal, and a first output terminal; the second amplifier has a second non-inverting input terminal, a second inverting input terminal, and a second output terminal; the first non-inverting input terminal is coupled to one of the two electrodes, the second non-inverting input terminal is coupled to the other of the two electrodes, and the first inverting input terminal is coupled to the second inverting input terminal; the third amplifier has a third non-inverting input terminal, a third inverting input terminal, and a third output terminal; the third non-inverting input terminal is used to receive the second amplified signal output from the second output terminal, the third inverting input terminal is used to receive the first amplified signal output from the first output terminal, and the third output terminal is used to output the voltage sampling signal.

[0032] On the other hand, embodiments of this application also provide a screen assembly, including the aforementioned electromagnetic touch sensing device, wherein the electromagnetic touch sensing device and the electromagnetic touch screen are coupled.

[0033] In some embodiments, a capacitive touchscreen is further included, wherein the capacitive touchscreen is coupled to the electromagnetic touchscreen coupled to the electromagnetic touch sensing device.

[0034] On the other hand, embodiments of this application also provide an electronic device, including the aforementioned screen assembly.

[0035] On the other hand, embodiments of this application also provide a touch system, including the aforementioned electronic device and electromagnetic pen.

[0036] The embodiments of this application include at least the following beneficial effects: The electromagnetic touch screen has multiple electrodes extending along a first direction, and two adjacent electrodes form sensing coils arranged in the first direction. In this application embodiment, at least two electrodes are coupled by an impedance module, so that a loop is formed between the two coupled electrodes. Then, the voltage on the impedance module is collected by a voltage sampling module, and a voltage signal reflecting the current magnitude in the loop of the two electrodes can be obtained. Since the current direction in the sensing coil is the same, the direction of the voltage on the impedance module between the two electrodes is determined. Therefore, the position of the electromagnetic pen can be reflected by the position of the maximum voltage. Compared with the sampling method of directly sampling the current, which causes the current direction on the multiplexed electrodes between adjacent sensing coils to be opposite and makes it impossible to determine the position of the electromagnetic pen by the position of the maximum current signal, this application embodiment can accurately determine the position of the electromagnetic pen by the voltage sampling signal of the voltage sampling module.

[0037] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0038] The accompanying drawings are used to provide a further understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0039] Figure 1 is a schematic diagram of the arrangement of the driving coil and sensing coil provided in an embodiment of this application;

[0040] Figure 2 is a schematic diagram showing that the currents flowing through the shared electrodes of two adjacent sensing coils are opposite, according to an embodiment of this application.

[0041] Figure 3 is a schematic diagram of connecting an electromagnetic touch screen and an electromagnetic touch sensing device via a ribbon cable according to an embodiment of this application;

[0042] Figure 4 is a schematic diagram of the electromagnetic touch sensing device connected to the electromagnetic touch screen provided in the embodiment of this application;

[0043] Figure 5 is a schematic diagram of a resistor R being connected between two adjacent electrodes according to an embodiment of this application;

[0044] Figure 6 is a schematic diagram of a terminating resistor R between two electrodes of a sensing coil spaced a fixed number apart, provided in an embodiment of this application.

[0045] Figure 7 is a schematic diagram of a terminating resistor R between two electrodes of a sensing coil spaced randomly apart, provided in an embodiment of this application.

[0046] Figure 8 is a schematic diagram of an impedance module provided in an embodiment of this application;

[0047] Figure 9 is a schematic diagram of another structure of the impedance module provided in the embodiment of this application;

[0048] Figure 10 is a schematic diagram of another structure of the impedance module provided in the embodiment of this application;

[0049] Figure 11 is a schematic diagram of the structure of adding a switch module and an impedance module in series according to an embodiment of this application;

[0050] Figure 12 is a circuit diagram of a voltage sampling module using a fully differential operational amplifier provided in an embodiment of this application;

[0051] Figure 13 is a circuit diagram of a voltage sampling module using a single-ended operational amplifier provided in an embodiment of this application;

[0052] Figure 14 is a circuit diagram of a voltage sampling module using an instrumentation operational amplifier provided in an embodiment of this application. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0054] The electromagnetic screen is a touchscreen utilizing EMR technology. Used in conjunction with an electromagnetic pen, it allows for touch actions such as clicking and drawing, enabling high-precision operations like drawing, text editing, and annotation. The electromagnetic screen contains multiple electrodes (or simply electrodes). One end of each pair of electrodes is connected to the touch chip of the electromagnetic screen, forming a coil. These coils are independently configured. These coils are divided into drive coils and sensing coils. The drive coils are connected to the touch chip to receive drive signals, while the sensing coils are connected to the touch chip to receive magnetic field signals emitted by the electromagnetic pen. The drive coils are oriented in the same direction, and the sensing coils are oriented perpendicularly to each other. This arrangement of multiple independent, intersecting coils forms multiple grids corresponding to different areas of the electromagnetic screen surface. An electromagnetic pen includes a coil inductor and an oscillating transmitting circuit with a capacitor. During operation, the electromagnetic screen sends a driving signal to the driving coil, which induces a magnetic field on the surface of the electromagnetic screen. The coil inductor of the electromagnetic pen cuts the magnetic field lines on the surface of the electromagnetic field, inducing a current within the coil inductor and charging the capacitor. After charging, the capacitor emits a magnetic field to the outside at a certain resonant frequency through the oscillating circuit. The sensing coil of the electromagnetic touch screen receives the magnetic field emitted by the electromagnetic pen and induces a current within its own coil. The touch chip determines the location of the electromagnetic pen by collecting this induced current. Typically, the area covered by the magnetic field emitted by the electromagnetic pen has multiple sensing coils. All sensing coils in the covered area will induce a current. The sensing coil with the largest induced current is closest to the location of the electromagnetic pen. Therefore, the touch chip obtains multiple induced currents to form a current signal envelope, and identifies the sensing coil corresponding to the point with the maximum value of the current signal envelope as the sensing coil closest to the electromagnetic pen, thus determining the location of the electromagnetic pen.

[0055] The aforementioned electromagnetic touchscreen detects electromagnetic signals based on an independent coil structure, thereby determining the position of the electromagnetic pen. Since each coil has two electrodes, which need to be connected to the touch chip outside the touchscreen, the number of electrodes at the edge of the touchscreen is relatively large. This results in a large number of wires on the ribbon cable connecting the touchscreen to the touch chip, occupying a significant portion of the edge area and thus causing a large screen bezel. To reduce the screen bezel and enable the electromagnetic touchscreen to be used in narrow-bezel products such as mobile phones and tablets, the electrodes of adjacent coils are reused. That is, two adjacent coils have three electrodes; the first and second electrodes form one coil, and the second and third electrodes form another coil, thus forming a comb-like coil structure as shown in Figure 1. This design can reduce the number of output lines by half while maintaining the same number of coils and area, thus reducing the area of ​​the ribbon cable. It is suitable for products with narrow bezel screens. Furthermore, a time-division driving method can be used to flexibly drive a coil composed of any two electrodes, thereby enabling the calculation of touch coordinates of the electromagnetic touch screen based on the signals from the driving coil and the sensing coil.

[0056] For a comb-shaped sensing coil, when it receives a magnetic field signal emitted by an electromagnetic pen, a current in the same direction is formed in multiple sensing coils. However, in the electrode that serves as the common terminal, the current direction of adjacent sensing coils on that electrode is opposite, which means that the current on that electrode may be positive, negative, or zero. This causes the current signal envelope obtained by the touch chip to have points of abrupt change in current, that is, the current signal envelope is not monotonic, and the location of the electromagnetic pen cannot be determined directly by the maximum value of the current signal envelope. Referring specifically to the schematic diagram of only a few sensing coils shown in Figure 2, electrodes Rx1 and Rx2 constitute one sensing coil (hereinafter referred to as Rx1 & Rx2 coil), and electrodes Rx2 and Rx3 constitute another sensing coil (hereinafter referred to as Rx2 & Rx3 coil). These two sensing coils share electrode Rx2 as a common terminal. When the electromagnetic pen is above the Rx1 & Rx2 coil and the Rx2 & Rx3 coil, the direction of the induced current in both sensing coils is clockwise. The current I2A on electrode Rx2 is actually the result of the current coupling of the two adjacent sensing coils. Obviously, the current directions of the two sensing coils on electrode Rx2 are opposite. When the electromagnetic pen is close to the Rx1 & Rx2 coil, the direction of the current I2A on electrode Rx2 is positive. When the electromagnetic pen is close to the Rx2 & Rx3 coil, the direction of the current I2A on electrode Rx2 is negative. When the electromagnetic pen is exactly in the middle of these two sensing coils, the current I2A on electrode Rx2 is zero. Therefore, the comb-like structure mentioned above causes the current signal sampled on the electrodes to be positive, negative, or zero at different positions of the electromagnetic pen, making the current signal envelope non-monotonic and unable to accurately determine the position of the electromagnetic pen.

[0057] Based on this, embodiments of this application provide an electromagnetic touch sensing device, a screen assembly, an electronic device, and a touch system. The electromagnetic touch screen coupled to the electromagnetic touch sensing device has multiple electrodes extending along a first direction. Two adjacent electrodes form sensing coils arranged in the first direction. In this application embodiment, at least two electrodes are coupled through an impedance module, forming a loop between the coupled electrodes. Then, the voltage on the impedance module is sampled using a voltage sampling module to obtain a voltage signal reflecting the magnitude of the current in the loop between the two electrodes. Since the current direction in the sensing coil is the same, the direction of the voltage on the impedance module between the two electrodes is determined. Therefore, the position of the electromagnetic pen can be reflected by the position of the maximum voltage. Compared with the sampling method of directly sampling the current, which results in the current direction being opposite on the electrodes multiplexed between adjacent sensing coils and makes it impossible to determine the position of the electromagnetic pen by the position of the maximum current signal, this application embodiment can accurately determine the position of the electromagnetic pen through the voltage sampling signal of the voltage sampling module.

[0058] The electromagnetic touch sensing device is described below with reference to the accompanying drawings.

[0059] Referring to Figures 3 and 4, which illustrate an electromagnetic touch sensing device provided in an embodiment of this application, the device is used to couple to an electromagnetic touch screen. The electromagnetic touch screen includes multiple electrodes extending along a first direction, with two adjacent electrodes forming a sensing coil. The electromagnetic touch sensing device senses the changes in the electromagnetic field of each sensing coil caused by an electromagnetic pen on the electromagnetic touch screen, thereby sensing the position of the electromagnetic pen.

[0060] In this embodiment, the electromagnetic touch sensing device and the electromagnetic touch screen are coupled for signal interaction. The coupling can be achieved through a ribbon cable connection or by connecting their respective interfaces. For example, in Figure 3, the electromagnetic touch sensing device and the electromagnetic touch screen are connected via a ribbon cable, connecting the electrodes in the electromagnetic touch screen to the circuitry in the electromagnetic touch sensing device. The electromagnetic touch screen provides a first ribbon cable interface at its edge, and the electromagnetic touch sensing device provides a second ribbon cable interface. The electromagnetic touch screen and the electromagnetic touch sensing device are then connected via a ribbon cable connecting the first and second ribbon cable interfaces. Alternatively, in Figure 4, the electromagnetic touch sensing device integrates a ribbon cable, allowing direct connection to the first ribbon cable interface of the electromagnetic touch screen. This comb-like cable routing method reduces the number of wires on the ribbon cable, thus reducing the area occupied by the ribbon cable on the edge of the electromagnetic screen, enabling the electromagnetic touch screen and electromagnetic touch sensing device to be used in products with narrow bezels.

[0061] In this embodiment, the electromagnetic touch screen has a sensing coil in a first direction and a driving coil in a second direction. The driving coils are parallel to each other, the sensing coils are parallel to each other, and the driving coils and sensing coils are perpendicular to each other, forming a grid covering the display area of ​​the electromagnetic touch screen. Taking Figure 1 as an example, the electrodes of the sensing coil in the first direction (horizontal direction of Figure 1) are Rx0, Rx1, Rx2, Rx3, ..., Rxn, and the electrodes of the driving coil in the second direction (vertical direction of Figure 1) are Tx0, Tx1, Tx2, Tx3, ..., Txn. Each Rx electrode is shorted on the left side in Figure 1 (equivalent to being shorted to a common terminal), and each Rx electrode is connected to the electromagnetic touch sensing device on the right side in Figure 1. Each Tx electrode is shorted on the upper side in Figure 1 (equivalent to being shorted to another common terminal), and each Tx electrode is connected to the electromagnetic touch sensing device on the lower side in Figure 1. It is worth noting that although the driving coil and sensing coil both have n+1 electrodes as described above, the number of electrodes in the driving coil and the sensing coil may differ depending on the actual situation, in order to accommodate electromagnetic touch screens with different length and width dimensions.

[0062] According to commonly used receiving technology, the current signal on electrode Rx is directly acquired, and the location of the electromagnetic pen is determined by the maximum value of the current in the current signal envelope. This method is feasible in schemes where the coils are independent, because the current induced in each coil is independent and does not affect adjacent coils. However, in the comb structure mentioned above, as previously known, adjacent sensing coils share an electrode. Since the current induced by two adjacent sensing coils is in the same direction, the current direction on the electrode that serves as the common terminal is opposite, making it impossible to reflect the location of the electromagnetic pen based on the maximum value of the current signal envelope. Therefore, this embodiment uses a resistor termination to couple the two electrodes in the comb structure, forming a current path through the resistor between the two electrodes. Then, voltage sampling is performed on the resistor. In this way, the direction of the current flowing through the resistor is determined, and the direction of the sampled voltage value is also determined. Therefore, the voltage signal envelope obtained by the electromagnetic touch sensing device is monotonic. By analyzing the voltage signal envelope, the location of the electromagnetic pen can be reflected based on the maximum value, avoiding the problem in the current sampling scheme where the current is affected by the electrode that serves as the common terminal, which leads to an inaccurate determination of the electromagnetic pen's location.

[0063] Specifically, in this embodiment of the application, the electromagnetic touch sensing device includes:

[0064] Impedance module for coupling at least two electrodes;

[0065] The voltage sampling module is used to sample the voltage on the impedance module.

[0066] An electromagnetic touch sensing device is connected to the electrodes of an electromagnetic touch screen. An impedance module is set in the electromagnetic touch sensing device and connected between two electrodes selected from the electrodes of at least one sensing coil, so that the selected two electrodes form a loop through the impedance module. All electrodes of the comb-shaped sensing coil are short-circuited together. Therefore, one end of the two electrodes coupled to the impedance module is short-circuited, and the other end is connected to both ends of the impedance module. Thus, the loop formed by these two electrodes can also induce current under the magnetic field emitted by the electromagnetic pen. In this way, a sampling network as shown in Figure 5 can be formed. Each loop with an impedance module can be used to induce current under the action of the magnetic field emitted by the electromagnetic pen. The direction of the current in the loop is related to the direction of the magnetic field emitted by the electromagnetic pen. When the direction of the magnetic field emitted by the electromagnetic pen is determined, the direction of the current in the loop is also determined, and the current flowing through the impedance module is also determined. That is, there will be no positive and negative voltage at the same time. Therefore, multiple sampling voltage values ​​in the same direction can be collected by the voltage sampling module to obtain a monotonic voltage signal envelope. Then, the position of the electromagnetic pen can be reflected by the maximum value of the voltage signal envelope.

[0067] It is worth noting that, to cover the entire effective touch area of ​​the electromagnetic touchscreen, at least within the effective touch area, the electrodes of each sensing coil are coupled to the aforementioned impedance module, so that each electrode forms a loop with another electrode. Regardless of the location of the electromagnetic pen within the effective touch area, the effective touch area has a corresponding loop that senses the magnetic field emitted by the electromagnetic pen. In addition to the effective touch area, the impedance module can also be coupled to two electrodes in the same manner to form a loop in the non-effective touch areas of the electromagnetic touchscreen; that is, the electrodes of each sensing coil of the entire electromagnetic touchscreen are coupled to an impedance module.

[0068] The voltage sampling module is coupled to the impedance module, collecting the voltage across the impedance module as the voltage sampling signal. This voltage sampling signal is proportional to the current in the loop containing the impedance module. To sample the impedance modules in each loop, the number of voltage sampling modules corresponds one-to-one with the number of impedance modules, and the two ends of the voltage sampling module are coupled to the two ends of the impedance module, or to the two electrodes forming the loop. This allows for coverage of all impedance modules, enabling the acquisition of signals from any position within the effective touch area of ​​the electromagnetic touchscreen.

[0069] The electromagnetic touch sensing device is equivalent to the touch chip of an electromagnetic touch screen, possessing the functions of a touch chip such as sending drive signals, acquiring sensing signals, and analyzing sensing signals. In this embodiment, the electromagnetic touch sensing device, compared to a conventional touch chip, also provides an impedance module and a voltage sampling module corresponding to the impedance module. When the electromagnetic touch sensing device is connected to the ribbon cable interface of the electromagnetic screen, the impedance module of the electromagnetic touch sensing device is coupled to the electrodes of the electromagnetic screen to form a loop. Then, when the electromagnetic screen is working, the voltage of the impedance module in the loop is acquired by the voltage acquisition module to obtain a voltage sampling signal. The position of the electromagnetic pen above the electromagnetic screen is determined by analyzing the voltage signal envelope.

[0070] As mentioned above, the electromagnetic touch screen also includes multiple driving coils arranged along a second direction, which is perpendicular to the first direction. Each driving coil is driven so that the electromagnetic touch sensing device senses the change in the electromagnetic field of the overlapping portion of each sensing coil and the currently driven driving coil, thereby sensing the position of the electromagnetic pen.

[0071] During the operation of an electromagnetic touchscreen, a current is supplied to the drive coil via a drive signal. The drive coil generates a magnetic field on the surface of the touchscreen. The inductance of the coil in the electromagnetic pen charges its internal capacitor by cutting magnetic field lines, and then, through an oscillation circuit, the electromagnetic pen emits a magnetic field of a certain resonant frequency to the touchscreen. Since the sensing coils are arranged in the first direction, the position of the electromagnetic pen can only be determined in one direction by judging the induced current of the sensing coil under the magnetic field emitted by the electromagnetic pen. Therefore, the electromagnetic touch sensing device, or touch chip, needs to send a drive signal to the drive coil through a specific driving method, which, in conjunction with the signal collected by the sensing coil, determines the position of the electromagnetic pen in both the first and second directions. For example, for the comb-shaped drive coils shown in Figure 1, drive signals can be sequentially applied to each drive coil from left to right in a time-division manner. When a drive signal is applied to a certain drive coil, if a signal is induced in the sensing coil, it indicates that the electromagnetic pen is above that drive coil in the second direction. Then, by analyzing the signal envelope of the sensing coil, it can be determined which sensing coil the electromagnetic pen is above in the first direction. In this way, the position of the electromagnetic pen is determined by using the drive coils and sensing coils in mutually perpendicular directions, thereby determining the position of the electromagnetic pen on the two-dimensional plane of the electromagnetic touch screen. It can be understood that, in addition to sending drive signals to the drive coils from left to right in a time-division manner, other methods can be used to drive the drive coils. For example, drive signals can be applied to multiple adjacent drive coils simultaneously each time. After determining that the electromagnetic pen is located in the area of ​​these adjacent drive coils, drive signals can then be applied to these adjacent drive coils sequentially in a time-division manner, which can also determine which drive coil the electromagnetic pen is above. This application does not limit the driving method. For different driving methods, the electromagnetic touch sensing device analyzes the signal envelope during the process of receiving the sensing signal. However, based on the above-mentioned method of using an impedance module for voltage sampling, the electromagnetic touch sensing device determines the position of the electromagnetic pen according to the point with the maximum voltage in the signal envelope when analyzing the signal envelope.

[0072] Referring to the embodiment shown in FIG5, an impedance module (represented as resistor R in FIG5) is coupled between every two adjacent electrodes. That is, the two ends of the impedance module are respectively connected to the two adjacent electrodes, so that the two electrodes of each sensing coil in the electromagnetic touch sensing device are coupled with an impedance module.

[0073] In addition to the structure shown in Figure 5, the two electrodes can also be selected from two non-adjacent electrodes. In some embodiments, the two non-adjacent electrodes are spaced apart by a fixed number of electrodes, or by a different number of electrodes. The fixed number means that the number of electrodes between the two electrodes coupled to each impedance module is a fixed value, and the different number means that the number of electrodes between the two electrodes coupled to each impedance module is not all the same.

[0074] For example, referring to Figure 6, the electrodes of the sensing coil are arranged from top to bottom, starting with the top electrode Rx0 and sequentially numbered Rx1, Rx2, Rx3, ..., Rx2k+1, etc. The two ends of impedance module R0 are connected to electrodes Rx0 and Rxk, respectively; the two ends of impedance module R1 are connected to electrodes Rx1 and Rxk+1, respectively; the two ends of impedance module R2 are connected to electrodes Rx2 and Rxk+2, respectively; the two ends of impedance module Rk are connected to electrodes Rxk and Rx2k, respectively; the two ends of impedance module Rk+1 are connected to electrodes Rxk+1 and Rx2k+1, respectively; the two ends of impedance module Rk+2 are connected to electrodes Rxk+2 and Rx2k+2, respectively, and so on. There are k electrodes (k is an integer greater than or equal to 2) between the two electrodes coupled to the impedance modules, thus forming multiple loops. Accordingly, V0, V1, ..., Vk+1, Vk+2 represent the correspondence between different voltage sampling modules and loops. The loop containing the impedance module R0 is connected to the voltage sampling module V0, the loop containing the impedance module R1 is connected to the voltage sampling module V1, the loop containing the impedance module R2 is connected to the voltage sampling module V2, the loop containing the impedance module Rk is connected to the voltage sampling module VK, the loop containing the impedance module Rk+1 is connected to the voltage sampling module VK+1, the loop containing the impedance module Rk+2 is connected to the voltage sampling module VK+2, and so on.

[0075] For example, as shown in Figure 7, the electrodes of the sensing coil are arranged from top to bottom, starting with the top electrode Rx0 and sequentially numbered Rx1, Rx2, Rx3, ..., Rxn. The two ends of impedance module R0 are connected to electrodes Rx0 and Rxi, respectively. The two ends of impedance module R1 are connected to electrodes Rx1 and Rxj, respectively. The two ends of impedance module R2 are connected to electrodes Rx2 and Rxk, respectively. The two ends of impedance module Ri are connected to electrodes Rxi and Rxl, respectively. The two ends of impedance module Rj are connected to electrodes Rxj and Rxm, respectively. The two ends of impedance module Rk are connected to electrodes Rxk and Rxn, respectively. The number of electrodes between the two electrodes coupled to the impedance modules is not a fixed value (i,j,k,l,m,n are all integers greater than 2, and i,j,k,l,m,n increase in sequence), thus forming multiple loops. Accordingly, V0, V1, ..., Vj, Vk represent the correspondence between different voltage sampling modules and loops. For the loop containing impedance module R0, voltage sampling module V0 is connected; for the loop containing impedance module R1, voltage sampling module V1 is connected; for the loop containing impedance module R2, voltage sampling module V2 is connected; for the loop containing impedance module Ri, voltage sampling module Vi is connected; for the loop containing impedance module Rj, voltage sampling module Vj is connected; for the loop containing impedance module Rk, voltage sampling module Vk is connected, and so on.

[0076] The structures in Figures 6 and 7 are variations of the structure in Figure 5. By forming a loop across multiple electrodes, the loop corresponds to a larger sensing range on the electromagnetic touchscreen, allowing for the sensing of a wider range of magnetic fields emitted by the electromagnetic pen. This facilitates the electromagnetic touch sensing device obtaining a larger range of voltage sampling signals, improving the accuracy of pen position determination. It is understood that the structures in Figures 5, 6, and 7 can be used interchangeably in the same electromagnetic touchscreen. The touchscreen is divided into multiple areas, and the coils in different areas can use any one of the structures in Figures 5, 6, and 7. Alternatively, coils within the same area can use any two or more of the structures in Figures 5, 6, and 7. This application does not impose any restrictions on this.

[0077] It is understandable that an electromagnetic touch sensing device includes multiple impedance modules, whose resistance values ​​can be the same or different. For example, in the structure shown in Figure 5, each resistor R is considered an impedance module. Resistor R is connected between two adjacent electrodes. If the resistance values ​​of each resistor R are equal, the magnitude relationship between the voltage signals of each loop received by the electromagnetic touch sensing device directly reflects the magnitude relationship of the induced current in the corresponding loop. In this way, the electromagnetic touch sensing device directly determines the position of the electromagnetic pen by judging the maximum value in the voltage signal envelope. When the electromagnetic pen is positioned above electrode Rx2, the induced currents in the coils of Rx1 & Rx2 and Rx2 & Rx3 are equal. Since the resistances R of the coils of Rx1 & Rx2 and Rx2 & Rx3 are equal, the current in electrode Rx2 is zero. At this time, the voltages across the resistances R of these two coils are equal. Although the voltage signal from the voltage sampling module has two maximum values, the voltage signal envelope of the electromagnetic touch sensing device can still determine the position of the electromagnetic pen using the maximum value. The determined position of the electromagnetic pen can be either located in the coils of Rx1 & Rx2 or in the coils of Rx2 & Rx3 (for example, the determination result is presented through the handwriting). This is determined according to the judgment strategy of the electromagnetic touch sensing device, but obviously, this will not result in a serious deviation in the determination of the position of the electromagnetic pen. If the resistance values ​​of resistors R are not equal, the electromagnetic touch sensing device needs to process the voltage sampling signal output by the voltage sampling module according to the resistance value of the corresponding resistor R in the loop. For example, the voltage sampling signal can be multiplied by a coefficient that is negatively correlated with the resistance value of the impedance module. Through this system, the voltage sampling signal can be adjusted to a uniform measurement standard, which makes it easier for the electromagnetic touch sensing device to determine the maximum value in the voltage signal envelope to determine the position of the electromagnetic pen.

[0078] In addition, the electromagnetic touch sensing device also includes a control module, which is coupled to the output of the voltage sampling module and configured to determine the position of the electromagnetic pen based on the voltage sampling signal output by the voltage sampling module. In some possible embodiments, the control module is the main logic control hardware of the electromagnetic touch sensing device, which couples the drive coil and the sensing coil in the circuit, sends a drive signal to the drive coil in a certain way, and receives the signal from the sensing coil (depending on the driving method, it may also receive signals from both the sensing coil and the drive coil), and then determines the position of the electromagnetic pen based on the received signal. In this embodiment, the control module is also coupled to the voltage sampling module and receives the voltage sampling signal output by the voltage sampling module. Since the electromagnetic touch sensing device is connected to the electromagnetic touch screen, and the two electrodes of the electromagnetic touch screen are coupled together to form a loop using an impedance module, the control module uses the voltage sampling signal instead of the traditional current sampling signal to determine the position of the electromagnetic pen. In some other possible embodiments, the control module is simply one of the logic control hardware components in the electromagnetic touch sensing device. It is circuitically coupled to the sensing coil and another logic control hardware component. This other logic control hardware component sends drive signals and synchronizes drive signals or drive modes with the control module. Thus, the control module can determine the location of the electromagnetic pen based on the received drive signals or drive modes and the voltage sampling signals received from the voltage sampling module. In other possible embodiments, the control module is simply one of the logic control hardware components in the electromagnetic touch sensing device. It is circuitically coupled to the sensing coil. Based on the voltage sampling signals received from the voltage sampling module, the control module provides a preliminary judgment result on the electromagnetic pen's location and sends this preliminary judgment result to the other logic control hardware component, which further determines the location of the electromagnetic pen. In summary, the control module interfaces with the voltage sampling module to receive voltage sampling signals and then preliminarily or ultimately determines the location of the electromagnetic pen based on the voltage signal envelope corresponding to the voltage sampling signals.

[0079] An impedance module can actually contain multiple resistive components such as resistors. Although the structure shown in Figure 5 depicts the impedance module as a resistor R, Figure 5 is a circuit topology diagram. Therefore, the resistor R may actually be a resistor network composed of multiple actual resistors. That is, the impedance module includes a resistor network, and the resistor network includes at least one resistor. The resistor network is used to couple the two electrodes. By using different resistor combinations, resistor networks with different resistance values ​​can be obtained, which can match electromagnetic touch screens and electromagnetic touch sensing devices with different requirements. In addition, capacitors can be added to the resistor network. The capacitors can be connected in series or parallel with one or more resistors in the resistor network, which can filter the electrical signal in the loop to a certain extent and improve the sampling accuracy of the downstream voltage sampling module.

[0080] In practical applications, an impedance module can consist of several resistors and capacitors. For example, the structure of an impedance module can take one of the following forms:

[0081] The resistor network includes a first resistor, and the impedance module also includes a first capacitor connected in parallel with the first resistor;

[0082] The resistor network includes a second resistor and a third resistor connected in series, and the impedance module also includes a second capacitor connected in parallel with the second resistor;

[0083] The resistor network includes a fourth and a fifth resistor connected in parallel, and the impedance module also includes a third capacitor connected in series with the fourth resistor.

[0084] The above three structures are illustrated by examples in Figures 8, 9 and 10.

[0085] Referring to Figure 8, the impedance module includes a first resistor (represented by resistor R in Figure 8) and a first capacitor (represented by capacitor C in Figure 8). Taking the impedance module between electrodes Rx0 and Rx1 as an example, resistor R forms a resistor network with its two ends connected to electrodes Rx0 and Rx1 respectively. Capacitor C is connected in parallel with resistor R. All other sensing coils in Figure 8 are connected to resistor R and capacitor C in the same manner. Capacitor C can be a device with a small capacitance value, used to filter high-frequency noise in the loop formed by the two electrodes and the impedance module.

[0086] Referring to Figure 9, the impedance module includes a second resistor (represented by resistor R1 in Figure 9), a third resistor (represented by resistor R2 in Figure 9), and a second capacitor (represented by capacitor C1 in Figure 9). Taking the impedance module between electrodes Rx0 and Rx1 as an example, resistors R1 and R2 are connected in series to form a resistor network, with electrodes Rx0 and Rx1 connected at their respective ends. Capacitor C1 is connected in parallel with resistor R1. All other sensing coils in Figure 9 are connected to resistors R1, R2, and capacitor C1 in the same manner. Capacitor C1 can be a device with a small capacitance value to filter high-frequency noise in the loop formed by the two electrodes and the impedance module. For impedance modules with two or more resistors connected in series to the two electrodes, the voltage sampling module can also be coupled to this series branch to sample the voltage of one of the resistors in the series branch.

[0087] Referring to Figure 10, the impedance module includes a fourth resistor (represented by resistor R1 in Figure 10), a fifth resistor (represented by resistor R2 in Figure 10), and a third capacitor (represented by capacitor C1 in Figure 10). Taking the impedance module between electrodes Rx0 and Rx1 as an example, resistors R1 and R2 are connected in parallel to form a resistor network, with the two ends of the resistor network connected to electrodes Rx0 and Rx1 respectively. Capacitor C1 is connected in series with resistor R1. All other sensing coils in Figure 10 are connected to resistors R1, R2, and capacitor C1 in the same manner. Capacitor C1 can be a device with a small capacitance value, used to filter high-frequency noise in the loop formed by the two electrodes and the impedance module.

[0088] It is worth noting that, in one driving method, the driving coil and sensing coil of the electromagnetic touch screen can be reused. In this case, both the driving coil and the sensing coil have the function of receiving driving signals and receiving magnetic field signals emitted by the electromagnetic pen. Therefore, these two types of coils are actually coils with the same function, differing only in their arrangement direction. In this driving method, the electromagnetic touch sensing device or touch chip sends a driving signal to the coil in the first direction at the first moment. At this time, the coil in the first direction is the driving coil, and the coil in the second direction is the sensing coil. The sensing coil receives the magnetic field signal emitted by the electromagnetic pen corresponding to the driving signal at the first moment. Thus, the electromagnetic touch sensing device or touch chip can determine the position of the electromagnetic pen in the second direction. Then, at the second moment, a driving signal is sent to the coil in the second direction. At this time, the coil in the second direction is the driving coil, and the coil in the first direction is the sensing coil. The sensing coil receives the magnetic field signal emitted by the electromagnetic pen corresponding to the driving signal at the second moment. Thus, the electromagnetic touch sensing device or touch chip can determine the position of the electromagnetic pen in the first direction. Since the time difference between the first moment and the second moment is very small, almost instantaneous, it is assumed that the position of the electromagnetic pen has not moved between these two moments. Therefore, the position of the electromagnetic pen on the electromagnetic touch screen is determined based on the position of the electromagnetic pen in the first direction and the position of the electromagnetic pen in the second direction. Under the above driving method, if the sensing coil uses the impedance module of this application, the circuit structure when the sensing coil is used as a driving coil needs to be considered. When the coil is terminated with the impedance module, it cannot be used normally as a driving coil due to the influence of the impedance module. Therefore, this application embodiment addresses the multiplexing scheme for driving coils and sensing coils, as shown in FIG11, by setting the impedance modules of the switching devices in series. When the switching device is closed, the corresponding coil acts as a sensing coil; when the switching device is open, the corresponding coil acts as a driving coil. In this way, the electromagnetic touch sensing device or touch chip can realize the above-mentioned multiplexing scheme for driving coils and sensing coils by switching the on / off state of the switching device. The switching device can be a highly integrated electrical switch such as a MOSFET or a transistor. The control terminal of the switching device is connected to the electromagnetic touch sensing device or touch chip, which controls whether the switching device is turned on or off based on which coil the current driving signal is sent to.

[0089] Voltage sampling modules can be implemented in various ways. For highly integrated electromagnetic touch sensing devices or touch chips, due to the large number of sensing coils, it is not suitable to use large components such as inductors in the voltage sampling module circuit. A more efficient approach is to use highly integrated operational amplifiers for differential comparison and output. In some embodiments, to ensure high sampling accuracy and guarantee the current in the loop formed by the two electrodes and the impedance module, a high-impedance input device is required for sampling. For example, the voltage sampling module may include a first amplifier G1, a second amplifier G2, and a third amplifier G3.

[0090] The first amplifier G1 amplifies the voltage of one of the two electrodes to generate a first amplified signal.

[0091] The second amplifier G2 amplifies the voltage of the other electrode among the two electrodes, generating a second amplified signal;

[0092] The third amplifier G3 amplifies the differential signal between the first and second amplified signals to obtain the voltage sampling signal.

[0093] When there is a high impedance input, the sampling signal of the voltage sampling module is relatively small. Therefore, the voltage sampling module in this embodiment of the application is equipped with two-stage amplification. The first stage amplification consists of a first amplifier G1 and a second amplifier G2, which amplify the voltage signals of the two electrodes coupled to the impedance module, respectively. The second stage amplification consists of a third amplifier G3, whose two input terminals are connected to the output terminals of the first amplifier G1 and the second amplifier G2. This is used to perform difference and amplification on the signals output by the first amplifier G1 and the second amplifier G2, thereby outputting the voltage sampling signal. The voltage sampling module adopts a two-stage amplifier circuit, which can achieve high integration while taking into account both high impedance input and signal amplification functions. It can process the signal, which is small in the case of the voltage sampling input signal on the impedance module of the electromagnetic touch screen, and finally output the voltage sampling signal of the voltage difference between the two electrodes.

[0094] The following examples, Figures 12, 13, and 14, illustrate the structure of several voltage sampling modules.

[0095] Referring to Figure 12, the first amplifier G1, the second amplifier G2, and the third amplifier G3 are all fully differential operational amplifiers. The first amplifier G1 is represented as the first fully differential operational amplifier U11 in Figure 12, the second amplifier G2 is represented as the second fully differential operational amplifier U21 in Figure 12, and the third amplifier G3 is represented as the third fully differential operational amplifier U12 in Figure 12. Wherein:

[0096] The first fully differential operational amplifier U11 has a first differential input terminal, a second differential input terminal, and a first output terminal. The first differential input terminal is coupled to one of the two electrodes, and the second differential input terminal is connected to the reference voltage VCMII. The second fully differential operational amplifier U21 has a third differential input terminal, a fourth differential input terminal, and a second output terminal. The third differential input terminal is coupled to the other of the two electrodes, and the fourth differential input terminal is connected to the reference voltage VCMII. The third fully differential operational amplifier U12 has a fifth differential input terminal, a sixth differential input terminal, and a third output terminal. The fifth differential input terminal is used to receive the first amplified signal output from the first output terminal, the sixth differential input terminal is used to receive the second amplified signal output from the second output terminal, and the third output terminal is used to output a voltage sampling signal.

[0097] Taking the coil formed by electrodes Rx0 and Rx1 in Figure 12 as an example, an impedance module (represented as resistor R in Figure 12) is connected between electrodes Rx0 and Rx1. The first differential input terminal of the first fully differential operational amplifier U11 and the third differential input terminal of the second fully differential operational amplifier U21 are connected to electrodes Rx0 and Rx1 respectively. The first differential input terminal of the first fully differential operational amplifier U11 is connected to the voltage source VCMI through a pull-up resistor R11, and the third differential input terminal of the second fully differential operational amplifier U21 is connected to the voltage source VCMI through a pull-up resistor R21. The pull-up resistors R11 and R12 are used to provide current bias for the first fully differential operational amplifier U11 and the second fully differential operational amplifier U21, while suppressing high-frequency interference signals in the coupling space between the drive coil and the sensing coil. The second differential input terminal of the first fully differential operational amplifier U11 is connected to the reference voltage VCMII through resistor R12, and the fourth differential input terminal of the second fully differential operational amplifier U21 is connected to the reference voltage VCMII through resistor R22.

[0098] The first output terminal of the first fully differential operational amplifier U11 includes two output terminals. One output terminal is connected to the fifth differential input terminal of the third fully differential operational amplifier U12 through resistor R14, and the other output terminal is connected to the sixth differential input terminal of the third fully differential operational amplifier U12 through resistor R15. Resistors R12 and R13 and capacitor C11 of the first fully differential operational amplifier U11 determine the amplification gain. The capacitance value of capacitor C11 is very small, and its function is to filter out high-frequency noise outside the band (capacitor C11 can also be omitted from the circuit of the first fully differential operational amplifier U11). Therefore, the in-band gain of the first fully differential operational amplifier U11 can be considered as k1 = R13 / R12 + 1. Similarly, the second output of the second fully differential operational amplifier U21 includes two outputs. One output is connected to the sixth differential input of the third fully differential operational amplifier U12 through resistor R18, and the other output is connected to the fifth differential input of the third fully differential operational amplifier U12 through resistor R19. Resistors R22 and R23 and capacitor C21 of the second fully differential operational amplifier U21 determine the amplification gain. The capacitance value of capacitor C21 is very small, and its function is to filter out high-frequency noise outside the band (capacitor C21 can also be omitted from the circuit of the second fully differential operational amplifier U21). Therefore, the in-band gain of the second fully differential operational amplifier U21 can be considered as k2 = R23 / R22 + 1. To facilitate the analysis of voltage signal envelope by the electromagnetic touch sensing device, the gain k1 of the first fully differential operational amplifier U11 can be set to be the same as the gain k2 of the second fully differential operational amplifier U21. This allows the signals amplified by the same factor on electrodes Rx0 and Rx1 to be output to the third fully differential operational amplifier U12.

[0099] The third fully differential operational amplifier U12 primarily takes the difference between the output signals of the first fully differential operational amplifier U11 and the second fully differential operational amplifier U21, thus extracting the voltage signal across the impedance module, i.e., the voltage difference signal between output electrodes Rx0 and Rx1. The third output terminal of the third fully differential operational amplifier U12 includes two output terminals, which are fed back to the fifth and sixth differential input terminals respectively through resistors R16 and R17. Capacitor C12 is connected in parallel with resistor R16, and capacitor C13 is connected in parallel with capacitor R17. Assuming the resistance values ​​R14 = R15 = R18 = R19, and the capacitance values ​​of capacitors C12 and C13 are very small, their function is to filter out out-of-band high-frequency noise (capacitors C12 and C13 can also be omitted from the circuit of the third fully differential operational amplifier U12). Therefore, the in-band amplification factor of the third fully differential operational amplifier U12 is k3 = R16 / R14.

[0100] The two-stage differential amplifier circuit described above, composed of fully differential operational amplifiers, can be used to acquire the voltage across the impedance module. By utilizing the characteristics of fully differential operational amplifiers—maximizing differential-mode gain and minimizing common-mode gain—a high common-mode rejection ratio can be achieved in the circuit, thereby reducing interference from external noise and improving the signal accuracy of the voltage sampling module.

[0101] The above example refers to the voltage sampling module between electrodes Rx0 and Rx1. For voltage sampling modules corresponding to other electrodes, such as the voltage sampling module between electrodes Rx1 and Rx2, it also includes a first amplifier G1, a second amplifier G2, and a third amplifier G3. These three are represented in Figure 12 as a fourth fully differential amplifier U31, a second fully differential amplifier U21, and a fifth fully differential amplifier U22, respectively. The aforementioned second fully differential amplifier U21 is multiplexed to the coils of electrodes Rx1 and Rx2. The second fully differential operational amplifier U21 and the fourth fully differential amplifier U31 corresponding to electrode Rx2 act as a first-stage amplifier, inputting the amplified signal to the fifth fully differential amplifier U22. The fifth fully differential amplifier U22 outputs the voltage difference signal between electrodes Rx1 and Rx2 with a certain amplification factor.

[0102] Referring to Figure 13, the first amplifier G1, the second amplifier G2, and the third amplifier G3 are all single-ended operational amplifiers. The first amplifier G1 is represented as the first single-ended operational amplifier U11 in Figure 13, the second amplifier G2 as the second single-ended operational amplifier U12 in Figure 13, and the third amplifier G3 as the third single-ended operational amplifier U13 in Figure 13. Wherein:

[0103] The first single-ended operational amplifier U11 has a first non-inverting input terminal, a first inverting input terminal, and a first output terminal. The first non-inverting input terminal is coupled to one of the two electrodes, and the first inverting input terminal is connected to the reference voltage VCMII. The second single-ended operational amplifier U12 has a second non-inverting input terminal, a second inverting input terminal, and a second output terminal. The second non-inverting input terminal is coupled to the other of the two electrodes, and the second inverting input terminal is connected to the reference voltage VCMII. The third single-ended operational amplifier U13 has a third non-inverting input terminal, a third inverting input terminal, and a third output terminal. The third non-inverting input terminal is used to receive the first amplified signal output from the first output terminal, the third inverting input terminal is used to receive the second amplified signal output from the second output terminal, and the third output terminal is used to output a voltage sampling signal.

[0104] Taking the coil formed by electrodes Rx0 and Rx1 in Figure 13 as an example, an impedance module (represented as resistor R in Figure 13) is connected between electrodes Rx0 and Rx1. The first non-inverting input of the first single-ended operational amplifier U11 and the second non-inverting input of the second single-ended operational amplifier U12 are connected to electrodes Rx0 and Rx1, respectively. The first non-inverting input of the first single-ended operational amplifier U11 is connected to the voltage source VCMI through a pull-up resistor R1, and the second non-inverting input of the second single-ended operational amplifier U12 is connected to the voltage source VCMI through a pull-up resistor R3. The pull-up resistors R1 and R3 are used to provide current bias for the first single-ended operational amplifier U11 and the second single-ended operational amplifier U12, while suppressing high-frequency interference signals in the coupling space between the driving coil and the sensing coil. The first inverting input of the first single-ended operational amplifier U11 is connected to the reference voltage VCMII through a resistor R2, and the second inverting input of the second single-ended operational amplifier U12 is connected to the reference voltage VCMII through a resistor R4.

[0105] The first output terminal of the first single-ended operational amplifier U11 is connected to the third non-inverting input terminal of the third single-ended operational amplifier U13 via resistor R7. The third non-inverting input terminal of the third single-ended operational amplifier U13 is also connected to the voltage source VCMI via pull-up resistor R6. Resistors R2 and R10 of the first single-ended operational amplifier U11 determine the amplification gain; therefore, the in-band gain of the first single-ended operational amplifier U11 can be considered as k1 = R10 / R2 + 1. Similarly, the second output terminal of the second single-ended operational amplifier U12 is connected to the third inverting input terminal of the third single-ended operational amplifier U13 via resistor R8. The second output terminal of the second single-ended operational amplifier U12 is also connected to the third input terminal of the third single-ended operational amplifier U13 via resistors R8 and R9. Resistors R4 and R5 of the second single-ended operational amplifier U12 determine the amplification gain; therefore, the in-band gain of the second single-ended operational amplifier U12 can be considered as k2 = R5 / R4 + 1. To facilitate the analysis of voltage signal envelope by the electromagnetic touch sensing device, the gain k1 of the first single-ended operational amplifier U11 can be set to be the same as the gain k2 of the second single-ended operational amplifier U12. This allows the signals amplified by the same factor on electrodes Rx0 and Rx1 to be output to the third single-ended operational amplifier U13.

[0106] The third single-ended operational amplifier U13 primarily takes the difference between the output signals of the first single-ended operational amplifier U11 and the second single-ended operational amplifier U12, thus extracting the voltage signal across the impedance module, i.e., the voltage difference signal between output electrodes Rx0 and Rx1. The third output terminal of the third single-ended operational amplifier U13 is fed back to the third inverting input terminal through resistor R9. Assuming resistor values ​​R7 = R8 and R6 = R9, the in-band gain of the third single-ended operational amplifier U13 is k3 = R9 / R8.

[0107] The two-stage differential amplifier circuit composed of a single-ended operational amplifier described above can be used to acquire the voltage across the impedance module. Utilizing the simple structure and low cost of single-ended amplifiers, the size of the electromagnetic touch sensing device can be reduced, as can material costs.

[0108] The above example refers to the voltage sampling module between electrodes Rx0 and Rx1. For voltage sampling modules corresponding to other electrodes, such as the voltage sampling module between electrodes Rx1 and Rx2, it also includes a first amplifier G1, a second amplifier G2, and a third amplifier G3. These three are represented in Figure 13 as a fourth single-ended amplifier U21, a fifth single-ended amplifier U22, and a sixth single-ended amplifier U23, respectively. For example, the fourth single-ended amplifier U21 and the fifth single-ended amplifier U22 corresponding to electrodes Rx1 and Rx2 act as a first-stage amplifier, inputting the amplified signal to the sixth single-ended amplifier U23. The sixth single-ended amplifier U23 outputs the voltage difference signal between electrodes Rx1 and Rx2 with a certain amplification factor.

[0109] It is worth noting that although each sensing coil in Figure 13 is equipped with a first amplifier G1, a second amplifier G2, and a third amplifier G3, the signal from electrode Rx1 is supplied not only to the second amplifier G2 in coils Rx0 and Rx1, but also to the first amplifier G1 in coils Rx1 and Rx2. The structures of these two amplifiers (including the resistance values ​​of the surrounding resistors) can actually be the same. Therefore, in some possible embodiments, the number of single-ended operational amplifiers in Figure 13 can be reduced by replacing the second amplifier G2 in coils Rx0 and Rx1 and the first amplifier G1 in coils Rx1 and Rx2 with a single operational amplifier. The non-inverting input of this operational amplifier is connected to electrode Rx1, the inverting input is connected to the voltage source VCMI through a resistor, and the output is divided into two paths: one path is supplied to the third amplifier G3 in coils Rx0 and Rx1, and the other path is supplied to the third amplifier G3 in coils Rx1 and Rx2. This can also realize the output of the voltage difference signal across the impedance module.

[0110] Referring to Figure 14, the first amplifier G1, the second amplifier G2, and the third amplifier G3 are all single-ended operational amplifiers, and are connected to form an instrumentation operational amplifier structure. The first amplifier G1 is represented as the first single-ended operational amplifier U11 in Figure 14, the second amplifier G2 as the second single-ended operational amplifier U12 in Figure 14, and the third amplifier G3 as the third single-ended operational amplifier U13 in Figure 14. Wherein:

[0111] The first single-ended operational amplifier U11 has a first non-inverting input terminal, a first inverting input terminal, and a first output terminal. The second single-ended operational amplifier U12 has a second non-inverting input terminal, a second inverting input terminal, and a second output terminal. The first non-inverting input terminal is coupled to one of the two electrodes, the second non-inverting input terminal is coupled to the other of the two electrodes, and the first inverting input terminal is coupled to the second inverting input terminal. The third single-ended operational amplifier U13 has a third non-inverting input terminal, a third inverting input terminal, and a third output terminal. The third non-inverting input terminal is used to receive the second amplified signal output from the second output terminal, the third inverting input terminal is used to receive the first amplified signal output from the first output terminal, and the third output terminal is used to output a voltage sampling signal.

[0112] Taking the coil formed by electrodes Rx0 and Rx1 in Figure 14 as an example, an impedance module (represented as resistor R in Figure 14) is connected between electrodes Rx0 and Rx1. The first non-inverting input terminal of the first single-ended operational amplifier U11 and the second non-inverting input terminal of the second single-ended operational amplifier U12 are connected to electrodes Rx0 and Rx1, respectively. The first non-inverting input terminal of the first single-ended operational amplifier U11 is connected to the voltage source VCMI through a pull-up resistor R1, and the second non-inverting input terminal of the second single-ended operational amplifier U12 is connected to the voltage source VCMI through a pull-up resistor R9. The pull-up resistors R1 and R9 are used to provide current bias for the first single-ended operational amplifier U11 and the second single-ended operational amplifier U12, while suppressing high-frequency interference signals in the coupling space between the driving coil and the sensing coil. A resistor consisting of resistors R2, R3, and R4 is provided between the first inverting input terminal of the first single-ended operational amplifier U11 and the second single-ended operational amplifier U12. The first output terminal of the first single-ended operational amplifier U11 is connected to the first inverting input terminal through resistor R3. The second output terminal of the second single-ended operational amplifier U12 is connected to the second inverting input terminal through resistor R4. A resistor R2 is provided between the first and second inverting input terminals. The output terminals of the two first-stage amplifiers (G1 and G2) of the instrumentation operational amplifier are connected to the two input terminals of the third single-ended operational amplifier U13. The first output terminal of the first single-ended operational amplifier U11 is connected to the third inverting input terminal of the third single-ended operational amplifier U13 through resistor R5. The second output terminal of the second single-ended operational amplifier U12 is connected to the third non-inverting input terminal of the third single-ended operational amplifier U13 through resistor R6. The third output terminal of the third single-ended operational amplifier U13 is also connected to the third inverting input terminal through resistor R7. The third non-inverting input terminal is also connected to the voltage source VCMI through resistor R8. The three single-ended amplifiers and the resistor network formed by them constitute an instrumentation amplifier. The gain of the instrumentation amplifier is determined by the internal resistor network. Assuming the resistor values ​​are R3 = R4, R5 = R6, and R7 = R8, then the in-band gain of the third single-ended operational amplifier U13 is k = (1 + 2 * R3 / R2) * R7 / R5.

[0113] The instrumentation operational amplifier, composed of a single-ended operational amplifier, described above, can be used to acquire the voltage across the impedance module. The instrumentation operational amplifier uses an internal feedback resistor network isolated from the signal input. Therefore, when an input signal is applied to the two differential input terminals of the instrumentation amplifier, its gain can be preset internally or set externally via a pin connected to an internal or external gain resistor. This gain resistor is also isolated from the signal input, thus offering advantages such as high common-mode rejection ratio, high input impedance, and low noise, thereby improving the signal accuracy of the voltage sampling module.

[0114] It is understandable that Figure 12 above refers to fully differential operational amplifiers, while Figures 13 and 14 above refer to single-ended amplifiers. However, in practical applications, various types of operational amplifiers can be combined to satisfy the functions of first-stage signal amplification and second-stage differential operation. For example, in Figure 12, the first amplifier G1 and the second amplifier G2 are single-ended operational amplifiers, and the third amplifier G3 is a fully differential operational amplifier. The output terminals of the two single-ended operational amplifiers are connected to the input terminal of the fully differential operational amplifier, and then the output terminal of the fully differential operational amplifier outputs the signal of the voltage difference across the impedance module.

[0115] In summary, the electromagnetic touch sensing device provided in this application embodiment is used to sense the signal of the electromagnetic touch screen to determine the position of the electromagnetic pen. The electromagnetic touch screen coupled to the electromagnetic touch sensing device has multiple electrodes extending along a first direction. Two adjacent electrodes form sensing coils arranged in the first direction. In this application embodiment, at least two electrodes are coupled through an impedance module, so that a loop is formed between the two coupled electrodes. Then, the voltage on the impedance module is collected by a voltage sampling module, and a voltage signal reflecting the current magnitude in the loop of the two electrodes can be obtained. Since the current direction in the sensing coil is the same, the direction of the voltage on the impedance module between the two electrodes is determined. Therefore, the position of the electromagnetic pen can be reflected by the position of the maximum voltage. Compared with the sampling method of directly sampling the current, which causes the current direction on the multiplexed electrodes between adjacent sensing coils to be opposite and makes it impossible to determine the position of the electromagnetic pen by the position of the maximum current signal, this application embodiment can accurately determine the position of the electromagnetic pen by the voltage sampling signal of the voltage sampling module.

[0116] This application also provides a screen assembly, including the electromagnetic touch sensing device in any of the above embodiments, wherein the electromagnetic touch sensing device and the electromagnetic touch screen are coupled together.

[0117] The screen assembly adopts the structure shown in Figure 3. The electromagnetic touch screen has multiple electrodes, numbered Rx0, Rx1, Rx2, Rx3, ..., Rxn from top to bottom. Each Rx electrode is shorted on the left side in Figure 3, and each Rx electrode is connected to the ribbon cable interface provided by the electromagnetic touch screen on the right side in Figure 3. The ribbon cable interface of the electromagnetic touch screen is connected to the ribbon cable interface of the electromagnetic touch sensing device via a ribbon cable. Adjacent Rx electrodes are shorted on the left side to form a sensing coil, thus adjacent sensing coils share a common electrode Rx, forming a sensing coil with a comb-like structure.

[0118] The electromagnetic touch sensing device includes an impedance module, a voltage sampling module, and a control module. The impedance module has multiple resistors R, the number of which corresponds to the number of sensing coils. When connected to the ribbon cable interface of the electromagnetic touch screen via a ribbon cable, the impedance module is coupled to the sensing coils of the electromagnetic touch screen through the wires in the ribbon cable. This couples the two ends of each resistor in the impedance module to the two electrodes Rx of each sensing coil, forming the circuit structure shown in Figure 5. The voltage sampling module has multiple voltage differential sampling modules, each connected in parallel with each resistor R in the impedance module. These modules are used to acquire the voltage difference between the two electrodes Rx of the sensing coil corresponding to resistor R and output a voltage sampling signal corresponding to that voltage difference. Specifically, the voltage sampling module includes a first amplifier, a second amplifier, and a third amplifier. The first amplifier is coupled to one electrode Rx of the sensing coil, the second amplifier is coupled to the other electrode Rx of the sensing coil, the outputs of the first and second amplifiers are connected to the two inputs of the third amplifier, and the output of the third amplifier is connected to the control module. The first amplifier amplifies the signal from one electrode Rx of the sensing coil and inputs it to the third amplifier. The second amplifier amplifies the signal from the other electrode Rx of the sensing coil and inputs it to the third amplifier. The third amplifier calculates the difference between the two input signals and outputs a differential signal, i.e., a voltage sampling signal. The control module performs voltage signal envelope analysis based on the voltage sampling signal to determine which sensing coil the electromagnetic pen is located above.

[0119] When the electromagnetic pen emits a magnetic field signal to the electromagnetic touch screen through its internal resonant circuit, a current is induced in the sensing coil in a region of the electromagnetic touch screen near the electromagnetic pen. At this time, the current in the sensing coil is in the same direction. However, since adjacent sensing coils share a common electrode Rx, to avoid the uncertainty of the current on the common electrode Rx being positive, negative, or zero, the solution of this application is adopted. The traditional current acquisition is changed to the acquisition of the voltage across the impedance module. Since the direction of the voltage across the impedance module is determined, and the magnitude of the voltage across the impedance module is positively correlated with the magnitude of the induced current in the sensing coil, the voltage can reflect the magnitude of the current in the sensing coil. Thus, the position of the electromagnetic pen can be determined by the maximum value of the voltage signal envelope, and the corresponding position of the electromagnetic pen on the electromagnetic touch screen can be displayed.

[0120] In some possible embodiments, the screen assembly further includes a capacitive touchscreen coupled to an electromagnetic touchscreen within a single screen, forming a multi-layered touchscreen structure. This touchscreen is coupled to the electromagnetic touch sensing device. The capacitive touchscreen can be located on top of the electromagnetic touchscreen (in which case the coils of the capacitive and electromagnetic touchscreens are arranged independently in the two layers), or it can be on the same layer as the electromagnetic touchscreen (in which case the coils of the capacitive and electromagnetic touchscreens may be multiplexed). Thus, in this embodiment, the screen assembly can implement capacitive touch functionality, such as for direct touch with a finger or capacitive stylus, or it can implement electromagnetic touch functionality, such as for touch with an electromagnetic pen.

[0121] This application embodiment also provides an electronic device, including the screen component described above. The screen component serves as both an input unit and a display unit of the electronic device. During the process of a user touching the screen component with an electromagnetic pen, the screen component receives the magnetic field signal emitted by the electromagnetic pen, inducing a current in the internal sensing coil. The electromagnetic touch sensing device of the screen component acquires voltage data from the impedance module terminated in the sensing coil, obtaining a voltage sampling signal that reflects the magnitude of the induced current in each sensing coil. Based on the magnitude of the voltage sampling signal, the position of the electromagnetic pen is determined, and then a display signal is sent to the screen component, causing the screen component to display content corresponding to the position of the electromagnetic pen under the drive of the display signal.

[0122] This application also provides a touch system, including the above-described electronic device and electromagnetic pen.

[0123] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatuses.

[0124] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0125] It should be understood that in the description of the embodiments of this application, "multiple" means two or more, "greater than", "less than", "exceeding" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself.

[0126] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0127] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0128] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0129] It should also be understood that the various implementation methods provided in this application can be combined arbitrarily to achieve different technical effects.

[0130] The above provides a detailed description of the preferred embodiments of this application. However, this application is not limited to the above-described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. An electromagnetic touch sensing device, characterized in that, For coupling to an electromagnetic touch screen, the electromagnetic touch screen includes multiple electrodes extending along a first direction, with two adjacent electrodes forming a sensing coil. The position of the electromagnetic pen is sensed by sensing the electromagnetic field changes of each sensing coil caused by the electromagnetic pen on the electromagnetic touch screen through the electromagnetic touch sensing device. The electromagnetic touch sensing device includes: An impedance module for coupling at least two of the electrodes; A voltage sampling module is used to sample the voltage on the impedance module.

2. The electromagnetic touch sensing device according to claim 1, characterized in that, The impedance module is coupled between each pair of adjacent electrodes.

3. The electromagnetic touch sensing device according to claim 1, characterized in that, The impedance module is coupled between two non-adjacent electrodes, and a predetermined number of electrodes are spaced between the two non-adjacent electrodes.

4. The electromagnetic touch sensing device according to claim 1, characterized in that, The impedance module is coupled between two non-adjacent electrodes, and the number of electrodes spaced between the two non-adjacent electrodes is not fixed.

5. The electromagnetic touch sensing device according to claim 1, characterized in that, The electromagnetic touch screen also includes a plurality of driving coils arranged along a second direction, which is perpendicular to the first direction. Each of the driving coils is driven so that the electromagnetic touch sensing device senses the change in the electromagnetic field of the overlapping portion of each sensing coil and the currently driven driving coil, thereby sensing the position of the electromagnetic pen.

6. The electromagnetic touch sensing device according to claim 5, characterized in that, The electromagnetic touch sensing device further includes a switching device connected in series with the impedance module, wherein, when the switching device is off, the sensing coil is used as the driving coil.

7. The electromagnetic touch sensing device according to claim 1, characterized in that, The electromagnetic touch sensing device further includes a control module, which is coupled to the output of the voltage sampling module and configured to determine the position of the electromagnetic pen based on the voltage sampling signal output by the voltage sampling module.

8. The electromagnetic touch sensing device according to claim 1, characterized in that, The impedance module includes a resistor network, which includes at least one resistor, for coupling the two electrodes.

9. The electromagnetic touch sensing device according to claim 8, characterized in that, The impedance module also includes a capacitor connected in series or in parallel with any of the resistors.

10. The electromagnetic touch sensing device according to claim 9, characterized in that, The impedance module has one of the following structures: The resistor network includes a first resistor, and the impedance module further includes a first capacitor connected in parallel with the first resistor; The resistor network includes a second resistor and a third resistor connected in series, and the impedance module also includes a second capacitor connected in parallel with the second resistor; The resistor network includes a fourth resistor and a fifth resistor connected in parallel, and the impedance module also includes a third capacitor connected in series with the fourth resistor.

11. The electromagnetic touch sensing device according to claim 1, characterized in that, The voltage sampling module includes a first amplifier, a second amplifier, and a third amplifier, wherein, The first amplifier amplifies the voltage of one of the two electrodes to generate a first amplified signal; The second amplifier amplifies the voltage of the other of the two electrodes to generate a second amplified signal; The third amplifier amplifies the differential signal between the first amplified signal and the second amplified signal to obtain a voltage sampling signal.

12. The electromagnetic touch sensing device according to claim 11, characterized in that, The first amplifier, the second amplifier, and the third amplifier are all fully differential operational amplifiers, wherein, The first amplifier has a first differential input terminal, a second differential input terminal, and a first output terminal. The first differential input terminal is coupled to one of the two electrodes, and the second differential input terminal is connected to a reference voltage. The second amplifier has a third differential input terminal, a fourth differential input terminal, and a second output terminal. The third differential input terminal is coupled to the other of the two electrodes, and the fourth differential input terminal is connected to a reference voltage. The third amplifier has a fifth differential input terminal, a sixth differential input terminal, and a third output terminal. The fifth differential input terminal is used to receive the first amplified signal output from the first output terminal, the sixth differential input terminal is used to receive the second amplified signal output from the second output terminal, and the third output terminal is used to output the voltage sampling signal.

13. The electromagnetic touch sensing device according to claim 11, characterized in that, The first amplifier, the second amplifier, and the third amplifier are all single-ended operational amplifiers, wherein, The first amplifier has a first non-inverting input terminal, a first inverting input terminal, and a first output terminal. The first non-inverting input terminal is coupled to one of the two electrodes, and the first inverting input terminal is connected to a reference voltage. The second amplifier has a second non-inverting input terminal, a second inverting input terminal, and a second output terminal. The second non-inverting input terminal is coupled to the other of the two electrodes, and the second inverting input terminal is connected to a reference voltage. The third amplifier has a third non-inverting input terminal, a third inverting input terminal, and a third output terminal. The third non-inverting input terminal is used to receive the first amplified signal output from the first output terminal, the third inverting input terminal is used to receive the second amplified signal output from the second output terminal, and the third output terminal is used to output the voltage sampling signal.

14. The electromagnetic touch sensing device according to claim 11, characterized in that, The first amplifier, the second amplifier, and the third amplifier are all single-ended operational amplifiers, wherein, The first amplifier has a first non-inverting input terminal, a first inverting input terminal, and a first output terminal; the second amplifier has a second non-inverting input terminal, a second inverting input terminal, and a second output terminal; the first non-inverting input terminal is coupled to one of the two electrodes, the second non-inverting input terminal is coupled to the other of the two electrodes, and the first inverting input terminal is coupled to the second inverting input terminal; the third amplifier has a third non-inverting input terminal, a third inverting input terminal, and a third output terminal; the third non-inverting input terminal is used to receive the second amplified signal output from the second output terminal, the third inverting input terminal is used to receive the first amplified signal output from the first output terminal, and the third output terminal is used to output the voltage sampling signal.

15. A screen assembly, characterized in that, Includes the electromagnetic touch sensing device as described in any one of claims 1 to 14, wherein the electromagnetic touch sensing device and the electromagnetic touch screen are coupled.

16. The screen assembly according to claim 15, characterized in that, It also includes a capacitive touch screen, which is coupled to an electromagnetic touch screen coupled to the electromagnetic touch sensing device.

17. An electronic device, characterized in that, Includes the screen component as described in claim 15 or 16.

18. A touch system, characterized in that, Includes the electronic device as described in claim 17 and the electromagnetic pen.

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