A touch screen with high antistatic and electromagnetic interference

Abstract

The application discloses a touch screen with high-strength anti-static and electromagnetic interference, comprising an ITO component (2), the ITO component (2) comprising a glass substrate and transparent ITO circuit coatings on both sides, the outer side of the ITO component being covered with SCA solid-state glue and protective glass, and the inner side being covered with OCA optical glue and an LCD display screen; the transparent ITO circuit coating on the inner side of the ITO component is provided with a signal transmitting circuit, the transparent ITO circuit coating on the outer side is provided with a sensor signal receiving circuit, and the signal transmitting circuit and the sensor signal receiving circuit are connected with an FPC circuit (3), the FPC circuit (3) being connected with an external main control system. The FPC circuit (3) is internally provided with a touch screen controller (4), a signal transmitting circuit, a sensor signal receiving circuit, a power supply circuit and an external interface circuit and the like; the anti-static and electromagnetic radiation interference capacity of the touch screen is improved, and the application has a positive social significance and a great engineering application value for developing and producing high-quality touch screen products, especially capacitive touch screen products.

Description

Technical Field

[0001] This invention relates to touch screen technology, and more particularly to a touch screen with high anti-static and anti-electromagnetic interference properties. Background Technology

[0002] Touchscreens, especially capacitive touchscreens, are widely used in mobile phones, laptops, supermarket payment devices, automotive electronics, and various electronic terminal devices, becoming indispensable components in industrial and agricultural production, as well as in people's daily work, study, and home life. At the same time, static electricity and electromagnetic pollution are becoming increasingly serious in modern industrial and social environments. Therefore, designing and manufacturing high-quality domestically produced touchscreens with strong anti-static and electromagnetic interference properties to meet the needs of special operating conditions has become an urgent historical task.

[0003] In existing technologies, no power isolation measures are taken between analog and digital power supplies in FPC circuits. 2 The lack of isolation between the C signal and the host computer, the absence of multi-layer board design in the FPC circuit flexible circuit board design, and the lack of shielding between the transmitting circuit and the sensor receiving circuit all contribute to numerous drawbacks. These shortcomings result in weak overall resistance to high-strength static electricity and electromagnetic interference in the ITO printed circuit and FPC circuit, failing to meet the growing market demand and thus hindering the rapid development of touch screens, especially capacitive touch screens.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a touch screen with high anti-static and anti-electromagnetic interference properties to solve the aforementioned technical problems in the prior art.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A touch screen with high antistatic and electromagnetic interference resistance includes an ITO component 2, wherein the ITO component 2 includes an ITO glass substrate and transparent ITO circuit coatings on both sides, the outer side is covered with transparent optical solid adhesive and protective glass, and the inner side is covered with transparent optical solid adhesive and LCD display screen.

[0008] The ITO component 2 has a transmitting signal circuit on the inner transparent conductive metal layer and a sensor signal receiving circuit on the outer transparent conductive metal layer. It is connected to the FPC circuit 3 through the transmitting signal circuit and the sensor signal receiving circuit. The FPC circuit 3 is connected to the external main control system.

[0009] Compared with the prior art, the touch screen with high anti-static and anti-electromagnetic interference provided by the present invention, specifically for capacitive touch screens, can overcome the various drawbacks of existing touch screens, especially capacitive touch screens, in the design and use process. Attached Figure Description

[0010] Figure 1 A schematic diagram of a touch screen with high anti-static and anti-electromagnetic interference properties is provided for embodiments of the present invention.

[0011] Figure 2 As described in the embodiments of the present invention, I 2 A schematic diagram of the specific electromagnetic isolation circuit and power isolation circuit for signal C.

[0012] In the picture:

[0013] 1. Touch screen structural components; 2. ITO components; 3. FPC circuit (flexible printed circuit board); 4. Touch screen controller.

[0014] 1.1 Glass cover plate, 1.2 SCA solid adhesive, 1.3 Indium tin oxide plating, 1.4 ITO glass substrate, 1.5 Indium tin oxide plating, 1.6 OCA optical adhesive, 1.7 LCD display screen. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them, and do not constitute a limitation on the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0016] First, the following explanations are provided for the terms that may be used in this article:

[0017] The terms “including,” “contains,” “comprising,” “having,” or other similar semantic descriptions shall be interpreted as non-exclusive inclusion.

[0018] The term "composed of" excludes any technical features not expressly listed. When used in a claim, it closes the claim to exclude all technical features other than those expressly listed, except for associated conventional impurities. If the term appears only in a clause of a claim, it limits the claim to the elements expressly listed in that clause; elements recited in other clauses are not excluded from the overall claim.

[0019] The terms “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “up,” “down,” “front,” “back,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” and “counterclockwise” indicate the current orientation or positional relationship, and are only for the convenience and simplification of description, and do not explicitly or implicitly suggest that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this document.

[0020] The technical solution provided by this invention will be described in detail below. Contents not described in detail in the embodiments of this invention are prior art known to those skilled in the art. Where specific conditions are not specified in the embodiments of this invention, they shall be performed according to conventional conditions in the art or conditions recommended by the manufacturer. Reagents or instruments used in the embodiments of this invention whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0021] like Figure 1 , Figure 2 As shown, a touch screen with high antistatic and electromagnetic interference resistance includes an ITO component 2. The ITO component 2 includes an ITO glass substrate 1.4 and transparent conductive metal layers on both sides. The outer side is covered with SCA solid adhesive and protective glass, and the inner side is covered with OCA optical adhesive and an LCD display screen.

[0022] A signal transmission circuit is fabricated on the transparent conductive metal layer on the inner side of the ITO component 2 using laser or printing processes. A sensor signal receiving circuit is fabricated on the transparent conductive metal layer on the outer side using laser or printing processes. The signal transmission circuit and the sensor signal receiving circuit are connected to the FPC circuit 3, and the FPC circuit 3 is connected to the external main control system.

[0023] The FPC circuit 3 includes a touch screen controller 4, a signal transmission circuit, a sensor signal receiving circuit, a power supply circuit, and an external interface circuit.

[0024] The external interface circuit includes an interrupt signal circuit, a reset signal circuit, and an I signal composed of SDA and SCL signals. 2 C communication circuit.

[0025] The transparent conductive metal layer uses materials such as indium tin oxide.

[0026] The outer edges of the transmitting signal circuit and the sensor signal receiving circuit on both the inner and outer sides of the ITO component are covered with a shielded grounding wire composed of a ring-shaped conductive line printed from indium tin oxide or metallic silver material.

[0027] The shielding grounding wire is a rectangular ring-shaped closed structure or a ring-shaped unclosed structure. The ring-shaped unclosed structure is a staggered shielding structure that has no gaps in the lateral direction and is not connected.

[0028] The FPC circuit 3 is a flexible circuit board with four or more layers. Taking four layers as an example, it includes:

[0029] The top layer is the signal layer, which contains signal lines from the sensor signal receiving circuit on the outer surface of the ITO component.

[0030] The second layer is the grounding layer, which serves as a shielding layer for laying grounding copper and power lines;

[0031] The third layer is the signal layer, which contains the transmission signal lines from the touch screen controller;

[0032] The bottom layer is the grounding layer, and copper plating serves as the shielding layer.

[0033] Each sensor signal receiving circuit in the FPC circuit is connected in series with a small impedance resistor or resistor array, and is placed at one end close to the touch screen controller.

[0034] In the touch screen controller pins of the FPC circuit, a filter capacitor is connected in parallel to the digital power supply pin, and the ground terminal of the filter capacitor is connected to the ground wire of the FPC circuit through a series inductor.

[0035] The output interface circuit of the FPC circuit is equipped with a dedicated electromagnetic isolation circuit for SDA and SCL signals. The input and output terminals of the dedicated electromagnetic isolation circuit are connected to the same set of external input power supplies. Power isolation transformation is performed to form two relatively independent power supplies, which are respectively connected to the power interface terminals at the input and output ends of the chip.

[0036] In summary, the embodiments of the present invention provide a touchscreen with high anti-static and anti-electromagnetic interference capabilities, comprising a touchscreen structural component, an ITO assembly, and an FPC circuit. The touchscreen structural component includes a glass cover, SCA solid adhesive, OCA optical adhesive, and an LCD display. These components are vertically stacked sequentially. The ITO assembly circuit includes a transmitting circuit and a receiving circuit. The FPC circuit includes a touchscreen controller, a power supply circuit, a signal circuit, and an interface circuit. This invention improves the anti-static and anti-electromagnetic interference capabilities of touchscreens, and has significant social and engineering application value for the research and development and production of high-quality touchscreen products, especially capacitive touchscreen products.

[0037] To more clearly demonstrate the technical solution and its effects provided by the present invention, the following detailed description of the touch screen with high anti-static and anti-electromagnetic interference provided by the present invention is based on specific embodiments.

[0038] Example 1

[0039] like Figure 1 As shown, the device comprises a touchscreen structural component 1, an ITO assembly 2, an FPC circuit 3, and a touchscreen controller 4. The touchscreen structural component 1 forms the main body of the touchscreen, and is composed of, from the outside to the inside, a glass cover plate 1.1, an SCA solid adhesive 1.2, an indium tin oxide plating layer 1.3, an ITO glass substrate 1.4, an indium tin oxide plating layer 1.5, an OCA optical adhesive 1.6, and an LCD display screen 1.7, stacked together.

[0040] The ITO glass substrate 1.4, along with its outer indium tin oxide plating 1.3 and inner indium tin oxide plating 1.5, constitute the ITO component 2. The outer side is covered with SCA solid adhesive and protective glass, the inner side is covered with OCA optical adhesive, and an LCD display screen is provided.

[0041] The circuit of the ITO component 2 includes a transmitting signal circuit and a sensor signal receiving circuit. The indium tin oxide plating layer 1.5 on the inner side and the indium tin oxide plating layer 1.3 on the outer side are respectively manufactured by circuit printing and other processing techniques. The transmitting signal circuit and the sensor signal receiving circuit are connected to the FPC circuit 3. The FPC circuit 3 is connected to the external main control system. The FPC circuit 3 is equipped with a touch screen controller 4.

[0042] On the inner and outer sides of the ITO layer of the touch screen ITO glass, "diamond" and other "green" patterns are designed and manufactured using circuit printing processes and other methods. The "touch point" coordinates and "gesture" judgment are performed by the "mutual capacitance" effect formed between the transmitting and receiving electrodes by the finger "touch point". On the outside of the circuit outside the effective touch area of ​​the aforementioned transmitting and receiving electrodes, rectangular grounding wires are evenly distributed. The grounding wires can be formed on the indium tin oxide plating layer 1.5 and the indium tin oxide plating layer 1.3 using laser engraving, circuit printing and other processes. The rectangular grounding wires can adopt a non-closed design. Generally, an opening of non-connection and shielding shape is designed and manufactured on the cross-section of the ground wire opposite the connection between the printed circuit and the FPC circuit. This measure can significantly reduce or eliminate the continuous oscillation phenomenon of the system caused by electromagnetic interference.

[0043] The FPC circuit 3 is a major component of the touchscreen hardware circuit. One end is connected to the ITO printed circuit via an interface circuit, and the other end is connected to signal lines and power lines from an external main control unit via an interface circuit. It includes the touchscreen controller, the transmitting signal circuit, the sensor signal receiving circuit, the power supply and power isolation circuit, the interrupt and reset circuit, and I... 2 C and I 2 C. Electromagnetic isolation circuit, and external interface circuit, etc.

[0044] Wherein, the I 2 C electromagnetic isolation circuit mainly relies on I 2 Electromagnetic isolation is achieved using specialized electromagnetic isolation chips, such as the NSI8100, to isolate the I / O circuit in the FPC circuit. 2 C signal and external connection to the main control system I 2 The C signal is electromagnetically isolated to avoid mutual interference between the electromagnetic signals of both parties; in conjunction with the aforementioned I... 2 Electromagnetic isolation between C signals and simple isolation processing of power supply signals are also performed. The isolation measures for the power supply section mainly use inductors L2 / L3 and filter capacitors C7~C10 as the main functional components to isolate the power input to the main control system into two parts with equal voltage values, namely the I signals. 2 The electromagnetic isolation circuit provides power to both sides; the grounding line of the power supply is also isolated. Simultaneously, the touchscreen controller often has an internal DC power supply, which needs to be isolated when necessary. Taking the GT911 touchscreen controller as an example, the controller chip has a digital power pin—DVDD12. This power pin requires an external filter capacitor for filtering, and the grounding terminal of the filter capacitor needs to be connected to the ground GND on the isolated power supply side through inductor L4.

[0045] The I 2 The specific electromagnetic isolation circuit and power supply isolation circuit for signal C, such as Figure 2 As shown.

[0046] This invention relates to a touchscreen with high anti-static and anti-electromagnetic interference properties, particularly a capacitive touchscreen design with high anti-static and anti-electromagnetic interference properties. The design comprises a touchscreen structural component, an ITO assembly, and an FPC circuit. The ITO assembly features a non-enclosed special structure for the grounding wires on both sides of the circuit exterior, and a small-value resistor is connected in series in the sensor receiving signal line. The FPC circuit employs a multi-layer circuit design to attenuate or completely isolate or shield the electromagnetic interference between the transmitted and received signals. 2Electromagnetic isolation is added to the line between the C signal and the host computer, and ground power isolation is added between the analog power supply and the digital DC power supply of the FPC circuit and the touch screen controller.

[0047] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. The information disclosed in the background section is intended only to enhance the understanding of the overall background technology of the present invention and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art.

Claims

1. A touchscreen with high anti-static and anti-electromagnetic interference properties, characterized in that, The ITO component (2) includes a glass substrate and transparent ITO circuit coatings on both sides, covered with SCA solid adhesive and protective glass on the outside, and covered with OCA optical adhesive and LCD display on the inside. The ITO component (2) has a transmitting signal circuit on the inner transparent ITO line plating layer and a sensor signal receiving circuit on the outer transparent ITO line plating layer. It is connected to the FPC circuit (3) through the transmitting signal circuit and the sensor signal receiving circuit. The FPC circuit (3) is connected to the external main control system.

2. The touchscreen with high anti-static and anti-electromagnetic interference properties according to claim 1, characterized in that, The FPC circuit (3) includes a touch screen controller (4), a signal transmission circuit, a sensor signal receiving circuit, a power supply circuit, and an external interface circuit.

3. The touchscreen with high anti-static and anti-electromagnetic interference properties according to claim 2, characterized in that, The external interface circuit includes an interrupt signal circuit, a reset signal circuit, and I / O signals for SDA and SCL. 2 C communication circuit.

4. The touchscreen with high anti-static and anti-electromagnetic interference properties according to claim 3, characterized in that, The transparent conductive metal layer uses materials such as indium tin oxide or graphene.

5. The touchscreen with high antistatic and electromagnetic interference properties according to claim 4, characterized in that, The outer edges of the transparent conductive metal layers on both sides of the transparent ITO circuit are covered with shielding grounding wires made of ring-shaped conductive lines printed from indium tin oxide or metallic silver.

6. The touchscreen with high anti-static and anti-electromagnetic interference properties according to claim 5, characterized in that, The shielding grounding wire is a rectangular ring-shaped closed structure or a ring-shaped unclosed structure. The ring-shaped unclosed structure is a staggered shielding structure that has no gaps in the lateral direction and is not connected.

7. The touchscreen with high antistatic and anti-electromagnetic interference properties according to any one of claims 1 to 6, characterized in that, The FPC circuit (3) is a flexible circuit board with 4 or more layers. Taking 4 layers as an example, it includes: The top layer is the signal layer, where sensor signal lines from the transparent ITO circuit coating on the outside of the ITO component are laid out; The second layer is the grounding layer, which serves as a shielding layer for laying grounding copper and power lines; The third layer is the signal layer, which contains the transmission signal lines from the touch screen controller; The bottom layer is the grounding layer, which serves as a shielding layer.

8. The touchscreen with high antistatic and electromagnetic interference properties according to claim 7, characterized in that, Each sensor signal receiving circuit in the FPC circuit is connected in series with a small impedance resistor or resistor array, and is placed at one end of the sensor signal receiving pin near the touch screen controller.

9. The touchscreen with high antistatic and electromagnetic interference properties according to claim 8, characterized in that, In the touch screen controller pins of the FPC circuit, a filter capacitor is connected in parallel to the digital power supply pin, and the ground terminal of the filter capacitor is connected to the ground wire of the FPC circuit through a series inductor.

10. The touchscreen with high anti-static and anti-electromagnetic interference properties according to claim 9, characterized in that, The output interface circuit of the FPC circuit is equipped with a dedicated electromagnetic isolation circuit for SDA and SCL signals. The input and output terminals of the dedicated electromagnetic isolation circuit are connected to the same set of external input power supplies. Power isolation transformation is performed to form two relatively independent power supplies, which are respectively connected to the power terminals at the input and output ends of the chip.

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