An anti-interference touch film

Abstract

The present invention discloses an anti-interference touch film comprising a touch-sensing layer for generating a touch-induced current and an electromagnetic shielding layer adjacent to the touch-sensing layer for shielding against electromagnetic interference from the surrounding environment. The electromagnetic shielding layer isolates the touch-sensing layer from the display screen. The touch-sensing layer and the electromagnetic shielding layer are connected to the ground via a first conductive wire and a second conductive wire, respectively, to conduct the induced current generated by electromagnetic interference to the ground. The anti-interference touch film of the present invention exhibits enhanced anti-interference performance and a good touch operation experience.

Description

Technical Field

[0001] The present invention relates to the field of touch technology, and more particularly to an anti-interference touch film. Background Art

[0002] A touch film is a key component of a touch screen, also known as a "touch screen" or "touch panel." It's an inductive touch device that receives input signals from a contact or other source. When a graphical button on the screen is touched, the on-screen tactile feedback system activates various connected devices according to pre-programmed signals, replacing mechanical button panels. When used with an LCD screen, it creates vivid audio and video effects. As the latest computer input device, the touch screen offers the simplest, most convenient, and most natural form of human-computer interaction. It has given multimedia a fresh look and is a highly attractive new multimedia interactive device. Its main applications include public information retrieval, leadership office work, industrial control, military command, electronic gaming, song and food ordering, multimedia education, and real estate pre-sales.

[0003] Taking capacitive touchscreens as an example, the principle of capacitive touchscreens is that when there's no touch or interference from a finger or capacitive stylus, the current flowing through the transmitting and receiving electrodes of the touch function layer (also called the "touch film") is stable. During a touch, a finger or capacitive stylus absorbs some of the charge from the touch function layer, causing the current to change. The control board uses this change in current to locate the touch point and transmit this information to the computer, ultimately achieving the touch control. However, the actual operating environment of a touchscreen is rife with electromagnetic interference from various sources. This occurs due to electromagnetic conversion, where fluctuating electromagnetic waves induce currents that cause current fluctuations in the receiving electrodes, misleading the control board's response and causing touch failure or false touches. While minor interference sources can be automatically ignored by the control board's software, circuit boards and displays with strong magnetic fields can generate significant current interference, with an effect similar to that of a finger or capacitive stylus. Therefore, the interference caused by the strong magnetic fields generated by these circuit boards and displays on capacitive touchscreens is a pressing issue for capacitive touchscreens.

[0004] Existing capacitive touch screens, including frame-mounted, full-fit and zero-fit touch screens, generally have a frame-mounted, full-fit or zero-fit sensor layer directly on the LCD screen. The disadvantage of this touch screen is that the LCD screen (including integrated circuits such as the power supply board) will generate relatively strong electromagnetic interference to the touch screen, resulting in reduced touch sensitivity and accuracy of the touch screen. The existing solution is to add a physical gap between the LCD layer and the touch screen, including an air layer, glass, acrylic, OCA film or transparent media such as curable water glue, to passively avoid electromagnetic interference to ensure the touch effect. However, this capacitive touch screen will still be greatly disturbed by the strong magnetic field generated by the surrounding circuit boards and displays, resulting in low touch sensitivity and poor experience for the capacitive touch screen. Summary of the Invention

[0005] In view of the shortcomings of existing touch screens, the present invention aims to provide an anti-interference touch film. Compared with existing touch films, the anti-interference touch film can greatly improve the resistance to electromagnetic interference from the surrounding environment.

[0006] To achieve the purpose of the present invention, the present invention adopts the following technical solutions:

[0007] An anti-interference touch film includes a touch function layer for generating a touch induced current and an electromagnetic shielding layer adjacent to the touch function layer for shielding electromagnetic interference from the surrounding environment. The electromagnetic shielding layer is used to separate the touch function layer from the display screen, and the touch function layer and the shielding layer are respectively connected to the ground through a first wire and a second wire, so as to conduct the induced current generated by the electromagnetic interference into the ground.

[0008] Preferably, the above-mentioned anti-interference touch film also includes a control board, which has a ground wire and includes a first connector and a second connector, and the first connector and the second connector are respectively connected to the above-mentioned first wire and the above-mentioned second wire, for conducting the induced current generated by electromagnetic interference into the ground, and the connection between the first connector and the first wire is also used to realize the touch function.

[0009] Preferably, the touch function layer includes at least one conductive layer composed of multiple insulated conductive threads in the X direction and multiple insulated conductive threads in the Y direction. One end of these insulated conductive threads is finally gathered to form a first wire and soldered to a first flexible circuit board. The first flexible circuit board is connected to the first connector.

[0010] Preferably, the electromagnetic shielding layer includes at least one shielding layer composed of one or more metal wires with insulating layers, at least one end of the metal wires with insulating layers are finally gathered to form a second conductor and welded on a second flexible circuit board, which is connected to the second connector.

[0011] Preferably, the electromagnetic shielding layer is a mesh structure formed by crossing one or more metal wires with insulating layers.

[0012] Preferably, the electromagnetic shielding layer is a parallel structure composed of one or more metal wires with insulating layers placed in parallel.

[0013] Preferably, the anti-interference touch film further comprises a cover glass located on the outermost side of the anti-interference touch film, for protecting the anti-interference touch film.

[0014] Preferably, the anti-interference touch film further comprises a double-sided adhesive film layer, one surface of which is adjacent to the touch function layer and is used to encapsulate the touch function layer, and the other surface of which is attached to the cover glass.

[0015] Preferably, the double-sided adhesive film layer comprises a substrate and a high-transmittance optical adhesive coated on both sides of the substrate.

[0016] Preferably, the anti-interference touch film further comprises a single-sided adhesive film layer, wherein the adhesive side of the single-sided adhesive film layer is adjacent to the electromagnetic shielding layer and is used to encapsulate the electromagnetic shielding layer.

[0017] Preferably, the single-sided adhesive film layer comprises a substrate and a high-transmittance optical adhesive coated on one side of the substrate.

[0018] The present invention also provides a touch display screen, which includes the above-mentioned anti-interference touch film.

[0019] The anti-interference touch film of the present invention is configured with an electromagnetic shielding layer adjacent to the touch function layer to separate it from the display screen to prevent electromagnetic interference generated by the display screen, and the touch function layer and the electromagnetic shielding layer are respectively connected to the ground through wires, so that the induced current formed by the interfering electromagnetic field near the touch function layer is introduced into the ground, thereby eliminating the electromagnetic interference to the touch function layer, ultimately providing a stable operating environment for the touch function layer, and finally providing an anti-interference touch film.

[0020] Compared with the prior art, the anti-interference touch film of the present invention has the advantages of reducing the influence of electromagnetic interference generated by the surrounding environment on its touch function layer at low cost and high efficiency, with high touch accuracy and good touch experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the embodiment drawings will be briefly introduced below. It is obvious that the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] Figure 1FIG. 1 is a schematic diagram of the structure of an anti-interference touch film according to an embodiment of the present invention.

[0023] Figure 2 FIG. 1 is a schematic structural diagram of a touch function layer according to an embodiment of the present invention.

[0024] Figure 3 Schematic diagram of the structure of an electromagnetic shielding layer according to an embodiment of the present invention.

[0025] Figure 4 FIG. 4 is a schematic structural diagram of an electromagnetic shielding layer according to another embodiment of the present invention.

[0026] Figure 5 Schematic diagram of the structure of a control panel according to an embodiment of the present invention.

[0027] Figure 1 —5 Bid No. Description:

[0028] 1—Anti-interference touch film, 10—Double-sided adhesive film layer, 11—Touch function layer, 12—Electromagnetic shielding layer, 13—Single-sided adhesive film layer, 14—Control board, 111—Insulated conductive wire in the X direction, 112—Insulated conductive wire in the Y direction, 15—First conductor, 113—First flexible circuit board, 121—Metal wire with an insulating layer in the X direction, 122—Metal wire with an insulating layer in the Y direction, 16—Second conductor, 123—Second flexible circuit board, 17—Cover glass, 141—First connector, 142—Second connector, 140—Ground wire. DETAILED DESCRIPTION

[0029] In the description of the present invention, the control board not only serves to ground the first and second conductive wires of the touch function layer and the electromagnetic shielding layer (thereby directing the induced current generated by the electromagnetic field of the surrounding environment of the touch function layer to the ground), but also serves to process the touch signal of the touch function layer and transmit the instruction to the computer to ultimately implement the touch function. In a preferred embodiment of the present invention, the control board includes two connectors (i.e., a first connector and a second connector). The first connector and the second connector are connected to the first conductive wire of the touch function layer and the second conductive wire of the electromagnetic shielding layer via a first flexible printed circuit board and a second flexible printed circuit board, respectively, to conduct the induced current generated by the electromagnetic field of the surrounding environment to the ground. The connection between the first connector and the first flexible printed circuit board is also used to transmit the touch signal of the touch function layer to the control board, which then processes the touch signal and transmits the instruction to the computer to ultimately implement the touch function.

[0030] In the present invention, the double-sided adhesive film layer and the single-sided adhesive film layer structure are provided with a transparent substrate. The transparent substrate can be selected from glass, polycarbonate (PC), polyethylene terephthalate (PET), and the like. The high-transmittance optical adhesive can be a commonly used high-transmittance optical adhesive in the art.

[0031] In the description of the present invention, the function of the touch functional layer is to generate a touch sensing current. Its structure can be the same as the structure of the touch layer (also known as the touch film) known in the art. For example, a plurality of X-direction insulated conductive threads and a plurality of Y-direction insulated conductive threads are continuously and cross-laid to form a certain pattern, such as a tic-tac-toe pattern or a swastika pattern, to form a touch area of the touch functional layer.

[0032] The insulated conductive filaments of the touch-sensitive functional layer of the present invention are selected from conductive metals, carbon nanotubes, graphene, or conductive polymers. In a preferred embodiment of the present invention, the insulated conductive filaments are selected from copper wires with an insulating layer. In a preferred embodiment of the present invention, the diameter of the conductive filaments is 10 to 15 μm.

[0033] In a preferred embodiment of the present invention, one end of multiple X-direction insulated conductive threads and multiple Y-direction insulated conductive threads in the touch functional layer are converged and soldered to a first flexible circuit board, forming the first conductive wire of the touch functional layer. This first conductive wire, on the one hand, directs the induced current generated by electromagnetic interference from the surrounding environment to the ground. On the other hand, when a finger or capacitive stylus touches the touch area, it absorbs some of the charge in the touch area, causing the current in the touch functional layer to change. The first conductive wire transmits the real-time current to the control board, which determines the position based on the current change and transmits this point information to the computer, ultimately achieving touch control.

[0034] In the present invention, the electromagnetic shielding layer is a mesh composed of insulating metal wires. This mesh can be formed by interlacing insulating metal wires in different directions, or by arranging insulating metal wires in parallel in the same direction. The insulating metal wires are selected from copper wire, nickel wire, iron wire, and the like. In a preferred embodiment of the present invention, the insulating metal wires are copper wires. In a preferred embodiment of the present invention, the copper wires have a diameter of 10 to 15 μm.

[0035] In a preferred embodiment of the present invention, the electromagnetic shielding layer comprises a mesh structure formed by the intersection of multiple X-direction insulated metal wires and multiple Y-direction insulated metal wires, wherein one end of the multiple X-direction insulated metal wires and one end of the multiple Y-direction insulated metal wires are brought together and soldered to a second flexible circuit board, forming a second conductor of the electromagnetic shielding layer for grounding. In a preferred embodiment of the present invention, the electromagnetic shielding layer comprises a mesh structure formed by the intersection of one X-direction insulated metal wire and one Y-direction insulated metal wire, wherein one end or both ends of the X-direction insulated metal wire and one end or both ends of the Y-direction insulated metal wire are brought together and soldered to a second flexible circuit board, forming a second conductor of the electromagnetic shielding layer for grounding.

[0036] In a preferred embodiment of the present invention, the electromagnetic shielding layer comprises a parallel structure of multiple X-direction (or Y-direction) insulated metal wires, one end of which is ultimately brought together and soldered to a second flexible printed circuit board, forming a second conductor of the electromagnetic shielding layer for grounding. In a preferred embodiment of the present invention, the electromagnetic shielding layer comprises a parallel structure of a single X-direction (or Y-direction) insulated metal wire, one end or both ends of which is ultimately brought together and soldered to a second flexible printed circuit board, forming a second conductor of the electromagnetic shielding layer for grounding.

[0037] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below with reference to embodiments and drawings.

[0038] Example 1

[0039] See also Figure 1 The anti-interference touch film 1 shown in this figure includes, arranged from top to bottom, a double-sided adhesive film layer 10, a touch function layer 11, an electromagnetic shielding layer 12, a single-sided adhesive film layer 13, a control board 14, and a flexible circuit board 15. The anti-interference touch film 1 of this embodiment may also include a cover glass 17 adjacent to the double-sided adhesive film layer 10, located on the outermost side of the anti-interference touch film 1, for protecting the anti-interference touch film.

[0040] In this embodiment, the structure of the touch function layer 11 is as follows: Figure 2As shown. The touch function layer 11 is composed of a plurality of X-direction insulated conductive wires (copper wires with an insulating layer) 111 and a plurality of Y-direction insulated conductive wires (copper wires with an insulating layer) 112. The X-direction insulated conductive wires 111 and the Y-direction insulated conductive wires 112 are approximately perpendicular at the intersection (non-contact intersection). The diameter of the inner copper wire of the copper wire with an insulating layer is 10um to 15um. One end of each X-direction copper wire with an insulating layer and each Y-direction copper wire with an insulating layer are finally gathered together to form the first wire 15 of the touch function layer and are soldered to the first flexible circuit board 113. The first flexible circuit board 113 is connected to the first connector 141 of the control board 14, and the first wire 15 is finally connected to the ground through the ground wire 140 of the control board 14. The connection between the first flexible circuit board 113 and the first connector 141 is also used to achieve the following: when a finger or a capacitive stylus touches the touch area formed by the multiple X-direction insulated conductive threads 111 and the multiple Y-direction insulated conductive threads, a portion of the charge in the touch area is absorbed, causing the current in the touch function layer to change. The control board 14 determines the position based on the current change received from the first flexible circuit board and transmits the point position information to the computer, ultimately achieving the touch purpose.

[0041] In this embodiment, the structure of the electromagnetic shielding layer 12 is as follows: Figure 3 As shown. The electromagnetic shielding layer 12 is composed of multiple X-direction insulated metal wires (insulated copper wires) 121 and multiple Y-direction insulated metal wires (insulated copper wires) 122. The X-direction insulated copper wires 121 and the Y-direction insulated copper wires 122 are approximately perpendicular at the intersection. The inner copper wire diameter of the insulated copper wire is 10um to 15um. One end of each X-direction insulated copper wire 121 and each Y-direction insulated copper wire 122 is finally brought together to form the second wire 16 of the touch function layer and soldered to the second flexible circuit board 123.

[0042] similar Figure 3 The grid structure of the electromagnetic shielding layer 12 shown can also be composed of a copper wire with an insulation layer in the X direction and a copper wire with an insulation layer in the Y direction. One end or both ends of the copper wire 121 with an insulation layer in the X direction and one end or both ends of the copper wire 122 with an insulation layer in the Y direction are finally gathered together to form the second wire 16 of the touch function layer and are welded to the second flexible circuit board 123.

[0043] In this embodiment, the structure of the electromagnetic shielding layer 12 can also be as follows Figure 4 As shown, the electromagnetic shielding layer 12 is a parallel structure formed by placing multiple insulated metal wires (insulated copper wires) 121 in parallel in one direction. The internal copper wire diameter of the insulated copper wires is 10μm to 15μm. One end of each insulated copper wire ultimately converges to form the second conductive wire of the touch function layer and is soldered to the second flexible circuit board 123.

[0044] similar Figure 4 The parallel structure of the electromagnetic shielding layer 12 shown can also be formed by a metal wire with an insulating layer, one end or both ends of the metal wire with an insulating layer are finally gathered to form the second wire 16 of the touch function layer and welded on the second flexible circuit board 123.

[0045] In this embodiment, the structure of the control board 14 is as follows Figure 5 The control board 14 has a ground line 140 and two connectors: a first connector 141 and a second connector 142. The first connector 141 and the second connector 142 are respectively connected to the first flexible printed circuit 113 and the second flexible printed circuit 123 connected to the first wire 113 and the second wire 123, so as to ground the first wire 15 and the second wire 16 through the ground line 140. The connection between the first connector 141 and the first flexible printed circuit 113 is also used to achieve touch control.

[0046] Of course, when the ends of the insulated conductive wires of the touch functional layer and the electromagnetic shielding layer and the metal wires with insulating layers are gathered and welded simultaneously on a flexible circuit board, or when the ends of the insulated conductive wires of the touch functional layer and the electromagnetic shielding layer and the metal wires with insulating layers are gathered and welded separately on multiple flexible circuit boards, the control board 14 has one or a corresponding number of multiple connectors.

[0047] In this embodiment, the double-sided adhesive film layer 10 is composed of a high-transmittance optical adhesive on a PET substrate and coated on both sides of the PET substrate, and the thickness of the optically transparent adhesive is 20 microns to 40 microns. One side of the double-sided adhesive film layer 10 is adjacent to the touch function layer, and the insulating conductive wire used to encapsulate the touch function layer, that is, the insulating conductive wire constituting the touch function layer is adhered to the double-sided adhesive film layer 10. The other side of the double-sided adhesive film layer 10 is attached to the cover glass (not shown in the figure). The structure of the single-sided adhesive film layer 13 is similar to that of the double-sided adhesive film layer 10, except that a high-transmittance optical adhesive is coated on one side of the PET substrate, and the thickness of the optically transparent adhesive is 20 microns to 40 microns. The side of the single-sided adhesive film layer 13 coated with adhesive is adjacent to the electromagnetic shielding layer, and the metal wire with an insulating layer used to encapsulate the electromagnetic shielding layer, that is, the metal wire with an insulating layer constituting the electromagnetic shielding layer is adhered to the single-sided adhesive film layer 13.

[0048] When the circuit board, display screen, etc. near the touch function layer generate strong electromagnetic waves, the electromagnetic waves form an interference current when they reach the touch function layer 11 and the electromagnetic shielding layer 12. The interference current passes through the first wire 15 and the second wire 16, then through the flexible circuit board, and finally directly into the ground through the control board 14. In this way, the touch function layer 11 is not disturbed by the strong magnetic field, making the touch effect stable and accurate.

[0049] Therefore, the anti-interference touch film of the present invention has good anti-interference performance, high touch sensitivity and good precision, and well ensures the display and touch experience of the touch display terminal.

[0050] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes based on the technical solutions and improved concepts of the present invention within the technical scope disclosed by the present invention, and these changes should be covered by the scope of protection of the present invention.

Claims

1. An anti-interference touch film, characterized in that: The anti-interference touch film includes a touch function layer for generating a touch sensing current and an electromagnetic shielding layer adjacent to the touch function layer for shielding electromagnetic interference from the surrounding environment. The electromagnetic shielding layer is used to separate the touch function layer from the display screen, and the touch function layer and the shielding layer are respectively connected to the ground via a first conductive wire and a second conductive wire. The anti-interference touch film further includes a control board having a ground line and including a first connector and a second connector, wherein the first connector and the second connector are connected to the first wire and the second wire respectively; The touch function layer includes at least one conductive layer composed of multiple insulated conductive threads in the X direction and multiple insulated conductive threads in the Y direction, one end of the insulated conductive threads is ultimately gathered to form a first conductive wire and is soldered to a first flexible circuit board, and the first flexible circuit board is connected to the first connector. The electromagnetic shielding layer includes at least one shielding layer composed of one or more metal wires with an insulating layer, at least one end of the metal wires with an insulating layer is ultimately gathered to form a second conductive wire and is soldered to a second flexible circuit board, and the second flexible circuit board is connected to the second connector. The electromagnetic shielding layer is a mesh or parallel structure composed of one or more metal wires with insulating layers placed crosswise or in parallel; The anti-interference touch film further comprises a double-sided adhesive film layer, one surface of the double-sided adhesive film layer is adjacent to the touch function layer and is used to encapsulate the touch function layer, and the other surface of the double-sided adhesive film layer is attached to the cover glass; The anti-interference touch film further includes a single-sided adhesive film layer, wherein the adhesive side of the single-sided adhesive film layer is adjacent to the electromagnetic shielding layer and is used to encapsulate the electromagnetic shielding layer.

2. The anti-interference touch film according to claim 1, characterized in that: The double-sided adhesive film layer comprises a substrate and a high-transmittance optical adhesive coated on both sides of the substrate.

3. The anti-interference touch film according to claim 1, characterized in that: The single-sided adhesive film layer comprises a substrate and a high-transmittance optical adhesive coated on one side of the substrate.

4. A touch display screen comprising the anti-interference touch film according to any one of claims 1 to 3.

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