Progressive line electromagnetic capacitive screen

Abstract

This utility model discloses a progressive circuit electromagnetic capacitive touchscreen, including a cover plate, an upper adhesive, an electromagnetic capacitor layer, a lower adhesive, and a liquid crystal display module. The electromagnetic capacitor layer contains a TX conductive layer, a PET substrate, and an RX conductive layer. Each TX channel within the TX conductive layer includes a first left-side edge trace, a second left-side edge trace, a first right-side edge trace, a second right-side edge trace, and an in-plane metal mesh trace. The trace width of each first left-side edge trace, each first right-side edge trace, and the traces between multiple first left-side edge traces, multiple first right-side edge traces, and multiple second right-side edge traces gradually decreases from the far end to the near end. The trace width of the second left-side edge trace and each second right-side edge trace remains unchanged. In this utility model, the impedance of the edge traces corresponding to each TX channel and each RX channel is consistent, compatible with both electromagnetic and capacitive functions, resulting in high touchscreen accuracy.

Description

Technical Field

[0001] This utility model relates to an electromagnetic capacitive screen, and more particularly to an electromagnetic capacitive screen with a progressive circuit. Background Technology

[0002] Electromagnetic capacitive touchscreens possess both electromagnetic and capacitive touch functions. To ensure compatibility with the touch and display functions of capacitive touchscreens, conventional electromagnetic capacitive touchscreens typically use PET electroplated copper (sheet resistance 0.05Ω / □) as the conductive material. Electromagnetic touchscreens, because transmittance is not a concern, generally use PVD water-plated copper (sheet resistance 10Ω / □). This significant difference in sheet resistance between the conductive materials of electromagnetic and capacitive touchscreens leads to a large resistance difference between the far-end and near-end channels of the integrated electromagnetic capacitive touchscreen. The near-end has lower resistance, while the far-end has higher resistance. This results in lower signal sensing at the far end and stronger signal sensing at the near end. This inconsistent signal sensing renders conventional electromagnetic touch solutions unsuitable, making it impossible to simultaneously support both electromagnetic and capacitive functions.

[0003] Meanwhile, the edge traces of conventional electromagnetic capacitive touchscreens are generally of equal spacing, such as 15µm line width and 15µm line spacing. According to the resistance calculation formula R = ρ*L / S = ρ*L / h*w, where ρ is the resistivity of the edge trace (which is constant), L is the length of the edge trace, S is the cross-sectional area of ​​the edge trace, h is the thickness of the edge trace, and w is the width of the edge trace (i.e., line width), since the resistivity, thickness, and width of the edge trace are fixed, but the length is not, the line resistance of the edge trace varies. The edge trace length L is shorter at the near end, resulting in a smaller line resistance R and a stronger signal sensing intensity; conversely, the edge trace length L is longer at the far end, resulting in a larger line resistance R and a weaker signal sensing intensity. This inconsistent signal sensing intensity renders conventional electromagnetic touch solutions unsuitable, thus preventing the simultaneous compatibility of electromagnetic and capacitive functions. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art by providing a progressive circuit electromagnetic capacitive screen that effectively integrates electromagnetic and capacitive functions, and offers high touch sensitivity for both capacitive and electromagnetic screens.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is: a progressive circuit electromagnetic capacitor screen, comprising a cover plate, an upper adhesive, an electromagnetic capacitor layer, a lower adhesive, and a liquid crystal display module arranged sequentially from top to bottom; the electromagnetic capacitor layer comprises a blackening layer, a TX conductive layer, a blackening layer, a PET substrate, a blackening layer, an RX conductive layer, and a blackening layer arranged sequentially from top to bottom.

[0006] The TX conductive layer includes multiple TX channels; each TX channel includes a first left-side edge trace, a second left-side edge trace, a first right-side edge trace, a second right-side edge trace, and an in-plane metal mesh trace; the first left-side edge trace and the second left-side edge trace are connected to form a left-side edge trace, the first right-side edge trace and the second right-side edge trace are connected to form a right-side edge trace, and the in-plane metal mesh trace is located between the left-side edge trace and the right-side edge trace, and the in-plane metal mesh trace overlaps and connects with the left-side edge trace and the right-side edge trace;

[0007] Among them, the line width of each of the first left edge traces and the first right edge traces gradually decreases from the far end to the near end; the line width of the traces between multiple first left edge traces and the line width of the traces between multiple first right edge traces also gradually decreases from the far end to the near end.

[0008] The trace width of each second left edge trace remains unchanged from the far end to the near end, and the trace width between multiple second left edge traces remains unchanged from the far end to the near end;

[0009] The trace width of each second right edge trace remains constant from the far end to the near end, while the trace width between multiple second right edge traces gradually decreases from the far end to the near end.

[0010] The RX channel and the TX channel have the same structure and are arranged perpendicularly to each other on the PET substrate.

[0011] Furthermore, the TX conductive layer and the RX conductive layer are made of metallic copper.

[0012] Furthermore, the multiple first left edge traces, the multiple second left edge traces, the multiple first right edge traces, and the multiple second right edge traces are all arranged in parallel.

[0013] Furthermore, the first left edge trace and the second left edge trace are vertically connected; the first right edge trace and the second right edge trace are also vertically connected.

[0014] Furthermore, the liquid crystal display module is a TFT liquid crystal display module, an IPS liquid crystal display module, or a flexible OLED display.

[0015] Furthermore, both the upper and lower adhesives are solid optically transparent adhesives, liquid silicone adhesives, or acrylic adhesives.

[0016] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art:

[0017] This invention relates to a progressive circuit electromagnetic capacitive touchscreen. By adjusting the trace width of the edge traces in different areas, the resistance of the edge traces is adjusted, ensuring that the impedance of the edge traces corresponding to each TX channel and each RX channel remains consistent. When the signal sensing at the far and near ends of the electromagnetic screen is consistent, the position and movement trajectory of the electromagnetic pen can be accurately located. It is also compatible with both electromagnetic and capacitive functions. This helps improve the consistency of the touch signal strength of the capacitive screen, ensuring that touch operations can be detected with equal sensitivity regardless of the area of ​​the screen, thus improving the accuracy of the touchscreen.

[0018] Secondly, by using copper, a metal with low sheet resistance, as the conductive material for the TX and RX conductive layers, the impedance of the in-plane metal grid channel of the electromagnetic screen and the in-plane metal grid channel of the capacitive screen are not significantly different. This results in similar signal induction at the far and near ends of the electromagnetic-capacitive screen, which is beneficial for providing compatibility between electromagnetic and capacitive functions. At the same time, the lower sheet resistance of copper can reduce the impedance of the in-plane metal grid channel of the electromagnetic screen and the impedance of the in-plane metal grid of the capacitive screen, further improving the touch sensitivity of the capacitive screen. Attached Figure Description

[0019] The technical solution of this utility model will be further described below with reference to the accompanying drawings:

[0020] Figure 1 This is a three-dimensional structural diagram of an embodiment of the present utility model;

[0021] Figure 2 This is a schematic diagram of the structure of the electromagnetic capacitor layer in one embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of the TX conductive layer and RX conductive layer disposed on a PET substrate in one embodiment of the present invention;

[0023] Figure 4 for Figure 3 Enlarged view of part A in the image;

[0024] Figure 5 for Figure 3 Enlarged view of part B in the image;

[0025] Figure 6 for Figure 3 Enlarged view of section C in the image;

[0026] Figure 7 for Figure 6 Enlarged view of part E in the image;

[0027] Figure 8 for Figure 3 Enlarged view of part D in the image;

[0028] Figure 9 for Figure 8 Enlarged view of part F in the image;

[0029] Figure 10 The impedance values ​​of different TX channels are shown in one embodiment of this utility model;

[0030] The components are: 1. Cover plate; 2. Upper adhesive; 3. Electromagnetic capacitor layer; 4. Lower adhesive; 5. Liquid crystal display module; 30. Blackening layer; 31. TX conductive layer; 32. PET substrate; 33. RX conductive layer; 310. First left edge trace; 311. Second left edge trace; 313. Second right edge trace; 314. In-plane metal mesh trace; 61. Left edge trace; 62. Right edge trace. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0032] This invention provides an electromagnetic capacitive touchscreen with a progressive circuit to solve the problems in the prior art where the signal sensing at the far end is low and the signal sensing at the near end is strong. The inconsistent signal sensing will make conventional electromagnetic touch solutions unsuitable, unable to simultaneously support electromagnetic and capacitive functions, and also result in low sensitivity.

[0033] For ease of understanding, the specific processes in the embodiments of this application are described below. Please refer to [link / reference]. Figure 1 An electromagnetic capacitive screen with a progressive circuit in this application embodiment includes a cover plate 1, an upper adhesive 2, an electromagnetic capacitor layer 3, a lower adhesive 4, and a liquid crystal display module 5 arranged sequentially from top to bottom.

[0034] The cover can be made of high-hardness materials such as glass, or relatively hard materials such as PC and PMMA, or soft materials such as PET, TAC, and PI. The most commonly used cover material is glass, with a thickness of 0.04mm to 3mm.

[0035] The upper adhesive 2 and the lower adhesive 4 can be a solid optical transparent adhesive, or a liquid silicone adhesive or acrylic adhesive, with high transmittance and strong adhesion. Their thickness can be a conventional thickness of 0.025mm to 0.3mm, or an unconventional thickness of 0.3mm to 2cm.

[0036] The liquid crystal display module can be a TFT liquid crystal display module, an IPS liquid crystal display module, or a flexible OLED display.

[0037] The electromagnetic capacitor layer 3 is a conductive layer of a certain thickness deposited on the front and back sides of the transparent flexible substrate 60 by magnetron sputtering. It is then processed by photolithography or imprinting processes involving exposure, development, and etching to obtain edge traces with a certain line width and spacing and an in-plane metal mesh pattern with a certain mesh width.

[0038] See Figure 2 The electromagnetic capacitor layer 3 in this invention consists of a blackening layer 30, a TX conductive layer 31, a blackening layer 30, a PET substrate 32, a blackening layer 30, an RX conductive layer 33, and a blackening layer 30 arranged sequentially from top to bottom, forming a seven-layer thin film structure. Both the front and back sides of the TX conductive layer 31 and the RX conductive layer 33 are coated with a blackening layer, which is an oxide such as copper oxide or copper nitride, used to protect the copper conductive layer and mask its color. The thickness is generally 20nm to 100nm. In this electromagnetic capacitive screen, to match electromagnetic touch and capacitive touch functions, the blackening layer thickness is 30nm to 50nm.

[0039] The impedance of a certain channel consists of the line resistance of the corresponding edge trace and the channel impedance of the corresponding in-plane metal mesh. Both the TX conductive layer 31 and the RX conductive layer 33 are composed of edge traces and in-plane metal mesh patterns.

[0040] See Figures 3 to 9 The TX conductive layer 31 includes multiple TX channels arranged opposite to each other, with a total of TXA channels, where A is greater than 1. Each TX channel includes a first left edge trace 310, a second left edge trace 311, a first right edge trace (not shown in the figure), a second right edge trace 313, and an in-plane metal mesh trace 314. The first left edge trace 310 and the second left edge trace are connected to form a left edge trace 61, and the first right edge trace and the second right edge trace 313 are connected to form a right edge trace 62. The multiple in-plane metal mesh traces 314 are located between the left edge traces 61 and the right edge traces 62, and the in-plane metal mesh traces 314 overlap and connect with the left edge traces 61 and the right edge traces 62.

[0041] Specifically, the trace width of each of the first left edge traces 310 and each of the first right edge traces (not shown in the figure) gradually decreases from the far end to the near end, where the far end refers to the end far from the second left edge trace 311 and the second right edge trace 313; the trace width between the plurality of first left edge traces 310 and the trace width between the plurality of first right edge traces also gradually decreases from the far end to the near end, where the far end refers to the end far from the in-plane metal mesh trace 314; the trace width of each of the second left edge traces 311 remains unchanged from the far end to the near end, and the trace width between the plurality of second left edge traces 311 remains unchanged from the far end to the near end; the trace width of each of the second right edge traces 313 remains unchanged from the far end to the near end, and the trace width between the plurality of second right edge traces 313 gradually decreases from the far end to the near end, where the far end refers to the end far from the second left edge trace 313. The RX channel and the TX channel have the same structure, and the RX channel and the TX channel intersect perpendicularly.

[0042] This invention relates to a progressive circuit electromagnetic capacitive touchscreen. The impedance of the RX and TX channels is composed of the line resistance of the corresponding edge traces and the channel impedance of the corresponding in-plane metal mesh. By adjusting the line width of the edge traces in different areas, the resistance of the edge traces is adjusted, ensuring that the impedance of the edge traces corresponding to each TX channel and each RX channel remains consistent. When the signal sensing at the far and near ends of the electromagnetic screen remains consistent, the position and movement trajectory of the electromagnetic pen can be accurately located. It is also compatible with both electromagnetic and capacitive functions. This helps improve the consistency of the touch signal strength of the capacitive screen, ensuring that touch operations can be detected with equal sensitivity regardless of the area of ​​the screen, thus improving the accuracy of the touchscreen.

[0043] like Figure 3 As shown, the left edge trace 61 and the right edge trace 62 are respectively connected to the TXA channels corresponding to the in-plane metal mesh area to form a complete RX channel. Therefore, the impedance of each RX channel = the line resistance corresponding to the first left edge trace area + the line resistance corresponding to the second left edge trace area + the line resistance corresponding to the first right edge trace area + the line resistance corresponding to the second right edge trace area + the line resistance corresponding to the in-plane metal mesh area.

[0044] Regarding the channel impedance of the in-plane metal mesh region, according to the resistance calculation formula R = ρ * L / S = ρ * L / h * w, since the resistivity ρ, thickness h, mesh linewidth w, and mesh line length L of the in-plane metal mesh in TXA are all the same, the channel impedance R of all channels within the in-plane metal mesh region is the same, and there is no difference in channel impedance. In this invention, multiple in-plane metal mesh traces 314 are designated as TX1, TX2, TX3 to TXA, meaning that the aforementioned in-plane metal mesh channel impedance R is the same, with no difference.

[0045] In this invention, the number of TX channels is set to TXA, where A is greater than 1. Regarding the line resistance of the edge traces of TXA, according to the resistance calculation formula R = ρ*L / S = ρ*L / h*w, since the resistivity ρ and thickness h of each segment of the edge traces in TXA are consistent, but the mesh length L of the edge traces is different, when conventional electromagnetic capacitive screens design the line width and spacing of the edge traces to be equal (i.e., the line width w of the edge traces is the same), the line resistance of the edge traces at different positions of TXA will differ due to the different mesh lengths L. The edge traces at the near end have a shorter length L, resulting in a smaller line resistance R and a stronger signal sensing intensity; the edge traces at the far end have a longer length L, resulting in a larger line resistance R and a weaker signal sensing intensity. Inconsistent signal sensing intensity will render conventional electromagnetic touch solutions unsuitable, making it impossible to simultaneously support electromagnetic and capacitive functions. Therefore, to ensure consistent line resistance of the edge traces of TXA, the line width w of the edge traces of different TXA needs to be designed according to the line length L of the edge traces of different TXA.

[0046] See Figures 4 to 6 The number of first left edge traces 310 and first right edge traces is TXA. One of their characteristics is that the trace width w of the same first left edge trace 310 and first right edge trace gradually decreases from the far end to the near end. As the length of the same first left edge trace and first right edge trace gradually decreases from the far end to the near end, the overall resistance of the edge trace tends to decrease. To balance the consistency of the resistance, the trace width needs to be gradually reduced to make the overall resistance of the edge trace tend to increase. Therefore, the trace width w of the same first left edge trace and first right edge trace gradually decreases from the far end to the near end. For example, the trace width of TX1 gradually decreases from top to bottom, and the trace width of TX2 also gradually decreases from top to bottom.

[0047] The second characteristic is that the trace width gradually decreases from the far end to the near end between different first left edge traces 310 and first right edge traces. For example, TX43 and TX1: at the far end, TX43 has a longer trace length, resulting in a higher overall resistance of the edge trace. To balance the resistance consistency of TXA, the trace width of the far-end TX43 edge trace needs to be increased to reduce the overall resistance of the edge trace, thus achieving balance. At the near end, TX1 has a shorter trace length, resulting in a lower overall resistance of the edge trace. To balance the resistance consistency of TXA, the trace width of the near-end TX1 edge trace needs to be decreased to increase the overall resistance of the edge trace, thus achieving balance. In other words, the trace width of the far-end TX43 is greater than the trace width of the near-end TX1. Therefore, the trace width gradually decreases from the far end to the near end between different first left edge traces 310 and first right edge traces.

[0048] See Figure 6 and Figure 7 The trace width within the second left edge trace 2 remains unchanged, mainly because the trace length of the edge trace in this area does not vary significantly compared to the trace length of the edge traces in other areas. The trace length of the edge trace in this area can be basically determined to be the same. According to the resistance calculation formula R=ρ*L / S=ρ*L / h*w, the resistivity ρ and thickness h of the edge trace in this area are consistent. Without affecting the overall resistance, the trace width w of the edge trace in this area can be designed to be the same.

[0049] See Figure 8 and Figure 9 Since the second right-side edge trace 313 is close to the pressure region, the closer this region is to the pressure center, the longer the pressure trace will be. Here, there are a total of 43 second right-side edge traces 313. Therefore, relatively speaking, TX1 is the longest, and TX43 is the shortest. TX1 is at the farthest end, and TX43 is at the closest end. The trace width of the same second right-side edge trace 313 remains constant from far to near. Theoretically, the trace width of the same second right-side edge trace 313 should continuously decrease from far to near. However, due to the limited vertical space in this region, it is difficult to support a progressive vertical trace design in this region. Therefore, the trace width within the same second right-side edge trace 313 remains constant.

[0050] The second characteristic is that the trace width of the different second right edge traces 313 gradually decreases from the far end to the near end. For example, TX43 and TX1: at the far end, TX1 has a longer trace length, resulting in a higher overall resistance of the edge trace. To balance the resistance consistency of TXA, the trace width of the far-end TX1 edge trace needs to be increased to reduce the overall resistance of the edge trace, thus achieving balance. At the near end, TX43 has a shorter trace length, resulting in a lower overall resistance of the edge trace. To balance the resistance consistency of TXA, the trace width of the near-end TX43 edge trace needs to be decreased to increase the overall resistance of the edge trace, thus achieving balance. In other words, the trace width of the far-end TX1 is greater than the trace width of the near-end TX43. Therefore, the trace width w of the different second right edge traces 313 gradually decreases from the far end to the near end.

[0051] In summary, by designing the trace width w within the same first left edge trace 310 and the same first right edge trace to gradually decrease from the far end to the near end, and by designing the trace width w between different first left edge traces 310 and between different first right edge traces to gradually decrease from the far end to the near end, the trace width within the second left edge trace 2 remains unchanged; the trace width within the same second right edge trace 313 remains unchanged, and the trace width w between different second right edge traces 313 to gradually decrease from the far end to the near end, while the impedance within the in-plane metal mesh remains unchanged, thus ensuring that the impedance within all TX channels remains consistent, and therefore the RX channel is the same as the TX channel.

[0052] Furthermore, the plurality of first left-side edge traces 310, the plurality of second left-side edge traces 311, the plurality of first right-side edge traces, and the plurality of second right-side edge traces 313 are all arranged in parallel.

[0053] Furthermore, the first left edge trace 310 and the second left edge trace 311 are vertically connected; the first right edge trace and the second right edge trace 313 are also vertically connected.

[0054] based on Figures 3 to 10 To facilitate understanding of this electromagnetic capacitive screen, the circuit design of the five regions of the TX conductive layer will be explained in detail below.

[0055] In this embodiment, for the same first left edge trace 310, starting from the farthest line width of 266um, the line width is gradually reduced. The line width of TX1 is continuously reduced to 255um, 200um, 155um, 133um, 122um, and 111um, until it is reduced to the nearest line width of 78um. The line design of different first left edge traces 310 from far to near is that the line width gradually decreases. Starting from the farthest TX43 line width of 211um, the line width of different TXA edge traces is gradually reduced. The line width of TX20 is reduced to 89um, the line width of TX9 is reduced to 78um, until it is reduced to the nearest line width of TX1 of 78um.

[0056] In this embodiment, for the first right edge trace, starting from the farthest line width of 120um, the line width is gradually reduced. The TX1 line width is continuously reduced to 115um, 90um, 70um, 60um, 55um, and 50um, until it is reduced to the nearest line width of 35um. The trace design for different TXA edge traces from far to near is that the trace width gradually decreases. Starting from the farthest TX43 line width of 50um, the trace widths of different TXA edge traces are gradually reduced. The TX20 line width is reduced to 40um, the TX9 line width is reduced to 35um, until it is reduced to the nearest TX1 line width of 35um.

[0057] In this embodiment, the length of the traces within the second left edge trace 311 remains unchanged, so the trace width of all second left edge traces remains unchanged and the trace width is designed to be 25um.

[0058] In this embodiment, the line width design of the second right edge trace 312 is as follows: For the same second right edge trace 312, due to the limited routing space in the vertical direction, the line width of the second right edge trace 312 remains unchanged and is designed to be 29um. Similarly, the line width of TX9 remains unchanged and is designed to be 25um, the line width of TX20 remains unchanged and is designed to be 22um, and the line width of TX43 remains unchanged and is designed to be 15um. However, the line width of different second right edge traces 312 gradually decreases from the far end to the near end. Starting from the farthest TX1 with a line width of 29um, the line widths of different TXA edge traces are gradually reduced. The line width of TX9 is reduced to 25um, the line width of TX20 is reduced to 22um, and so on until the line width of the nearest TX43 is reduced to 15um.

[0059] In this embodiment, the linewidth corresponding to the in-plane metal mesh area is designed to be 3.5um, with a tolerance of ±0.5um. Since the resistivity ρ, thickness h, mesh linewidth w, and mesh line length L of the in-plane metal mesh are all the same, the channel impedance R of all channels in the in-plane metal mesh area is the same and is 32Ω, and there is no difference in channel impedance.

[0060] Based on the above, the impedance of the five regions can be obtained in segments, thus obtaining the overall impedance of each channel of TXA.

[0061] See Figure 10 In this invention, the impedance of the first left edge trace in the first channel is set as TX1-left1, the impedance of the second left edge trace is set as TX1-left2, the impedance of the first right edge trace is set as TX1-right1, and the impedance of the second right edge trace is set as TX1-right2. Therefore, the impedance of TX1-left1 is 66.3Ω, the impedance of TX1-left2 is 17.2Ω, the impedance of TX1-right1 is 29.9Ω, the impedance of TX1-right2 is 69.7Ω, and the impedance of the in-plane metal mesh TX1 is 32Ω. Thus, the overall channel impedance of the entire TX1 is 215.2Ω.

[0062] In the ninth channel, TX9-left 1 has an impedance of 55.8Ω, TX9-left 2 has an impedance of 19.2Ω, TX9-right 1 has an impedance of 25.2Ω, TX9-right 2 has an impedance of 82.7Ω, and the in-plane metal mesh TX9 has a through impedance of 32Ω. Therefore, the overall channel impedance of the entire TX9 is 215Ω.

[0063] In the twentieth channel, TX20-left 1 has an impedance of 42.8Ω, TX20-left 2 has an impedance of 22Ω, TX9-right 1 has an impedance of 19.3Ω, TX20-right 2 has an impedance of 97Ω, and the in-plane metal mesh TX20 has a through impedance of 32Ω. Therefore, the overall channel impedance of the entire TX20 is 213.1Ω.

[0064] In the forty-third channel, TX43-left 1 has an impedance of 2.2Ω, TX43-left 2 has an impedance of 28.6Ω, TX43-right 1 has an impedance of 1Ω, TX43-right 2 has an impedance of 151.2Ω, and the in-plane metal mesh TX43 has a through impedance of 32Ω. Therefore, the overall channel impedance of the entire TX43 is 215Ω.

[0065] It can be seen that the overall channels of TX1, TX9, TX20, and TX43 are very similar. By analogy, the overall channels of the other TX1 to TX43 are not much different, all around 215Ω.

[0066] Similarly, by following the progressive circuit design described above, the impedance of all RX channels can be made to be similar.

[0067] When the electromagnetic pen approaches the sensing circuit of the electromagnetic screen, the electromagnetic field of the pen resonates with the electromagnetic field generated by the sensing circuit, causing a change in the signal sensing quantity of the sensing circuit. Since the overall channel impedances of the TX and RX channels are not significantly different, the control board compares and analyzes the signal sensing quantities of the sensing circuit to ensure that they remain basically consistent. There is no situation where the signal sensing quantity of the same channel is strong and weak. Therefore, the position and movement trajectory of the electromagnetic pen can be accurately located, and there will be no phenomenon of touch failure or insensitivity during the use of the electromagnetic pen, thus improving the user experience.

[0068] Furthermore, since the impedance of each channel in an electromagnetic screen is the same, and the electromagnetic capacitors in this electromagnetic capacitive screen are integrated conductive layers, the impedance of each channel in the capacitive screen is also the same. During the touch signal acquisition process, the characteristics of each channel in the electromagnetic capacitive screen are identical, allowing for a more accurate reflection of the touch point's position information. For example, in a touchscreen array composed of multiple sensing electrodes, if the channel impedances are inconsistent, the weak current generated by the touch will attenuate differently when transmitted through different channels due to resistance differences, leading to deviations in the calculated touch coordinates. If the impedances are consistent, the weak current generated by the touch will not attenuate when transmitted through different channels due to consistent resistance, resulting in accurate and unbiased calculated touch coordinates, thus improving the accuracy of capacitive touch control in the electromagnetic capacitive screen.

[0069] Furthermore, the TX and RX conductive layers are made of metallic copper, with a thickness typically ranging from 0.5µm to 3µm. The thicker the copper layer, the lower the sheet resistance; in this example, the sheet resistance of the copper is 0.02Ω / □. In contrast, the sheet resistance of the conductive layer in conventional electromagnetic capacitive screens is 1–10Ω / □. Relatively speaking, the sheet resistance of the conductive layer in this electromagnetic capacitive screen is even lower, resulting in a lower impedance for the in-plane metal mesh channel and thus a lower overall channel impedance.

[0070] As shown in the above progressive circuit design, the TX channel impedance is around 150Ω, while that of a conventional electromagnetic capacitive touchscreen is around 2KΩ. The TX channel impedance of this electromagnetic capacitive touchscreen is 3 / 40 times that of a conventional electromagnetic capacitive touchscreen, exhibiting a lower and more stable sheet resistance. Therefore, the low sheet resistance of the channel impedance in this electromagnetic capacitive touchscreen is beneficial to improving the sensitivity of the touchscreen. When the signal generated when touching the surface of the electromagnetic capacitive touchscreen is transmitted to the conductive layer, the lower the channel impedance, the less signal loss, and the shorter the time required for the capacitor to fully charge. The capacitor generates a potential and a signal only after it is fully charged. The more completely the signal enters the IC, the smoother the IC's signal interpretation, resulting in faster response and smoother touch for the user, i.e., higher sensitivity of the capacitive touchscreen.

[0071] This invention relates to a progressive circuit electromagnetic capacitive touchscreen that ensures consistent impedance between the TX and RX channels. When the signal sensing at the far and near ends of the electromagnetic screen remains consistent, the position and movement trajectory of the electromagnetic pen can be precisely located. It also supports both electromagnetic and capacitive functions. This improves the consistency of touch signal strength, ensuring that touch operations can be detected with equal sensitivity regardless of the area of ​​the screen, thus enhancing the accuracy of the touchscreen. Furthermore, the use of low-sheet-resistance copper as the conductive material for both the TX and RX conductive layers minimizes signal loss and further improves the touch sensitivity of the capacitive screen.

[0072] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. An electromagnetic capacitive screen with a progressive circuit, characterized in that, It includes a cover plate, an upper adhesive, an electromagnetic capacitor layer, a lower adhesive, and a liquid crystal display module arranged sequentially from top to bottom; the electromagnetic capacitor layer includes a blackening layer, a TX conductive layer, a blackening layer, a PET substrate, a blackening layer, an RX conductive layer, and a blackening layer arranged sequentially from top to bottom. The TX conductive layer includes multiple TX channels; each TX channel includes a first left-side edge trace, a second left-side edge trace, a first right-side edge trace, a second right-side edge trace, and an in-plane metal mesh trace; the first left-side edge trace and the second left-side edge trace are connected to form a left-side edge trace, the first right-side edge trace and the second right-side edge trace are connected to form a right-side edge trace, and the in-plane metal mesh trace is located between the left-side edge trace and the right-side edge trace, and the in-plane metal mesh trace overlaps and connects with the left-side edge trace and the right-side edge trace; Among them, the line width of each of the first left edge traces and the first right edge traces gradually decreases from the far end to the near end; the line width of the traces between multiple first left edge traces and the line width of the traces between multiple first right edge traces also gradually decreases from the far end to the near end. The trace width of each second left edge trace remains unchanged from the far end to the near end, and the trace width between multiple second left edge traces remains unchanged from the far end to the near end; The trace width of each second right edge trace remains constant from the far end to the near end, while the trace width between multiple second right edge traces gradually decreases from the far end to the near end. The RX conductive layer includes multiple RX channels; the RX channels and the TX channels have the same structure and are arranged perpendicularly to each other on the PET substrate.

2. The electromagnetic capacitive screen with a progressive circuit as described in claim 1, characterized in that: The TX conductive layer and the RX conductive layer are made of metallic copper.

3. The electromagnetic capacitive screen with a progressive circuit as described in claim 1, characterized in that: The multiple first left edge traces, the multiple second left edge traces, the multiple first right edge traces, and the multiple second right edge traces are all arranged in parallel.

4. The electromagnetic capacitive screen with a progressive circuit as described in claim 1, characterized in that: The first left edge trace and the second left edge trace are vertically connected; the first right edge trace and the second right edge trace are also vertically connected.

5. The electromagnetic capacitive screen with a progressive circuit as described in claim 1, characterized in that: The liquid crystal display module is a TFT liquid crystal display module, an IPS liquid crystal display module, or a flexible OLED display.

6. The electromagnetic capacitive screen with a progressive circuit as described in claim 1, characterized in that: Both the upper and lower adhesives are solid optical transparent adhesives, liquid silicone adhesives, or acrylic adhesives.

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