Touch screen module

Abstract

The utility model discloses a touch screen module which comprises cover plate glass, a sensor layer, a control chip and a flexible circuit. The sensor layer comprises a conductive grid and periodically distributed grounding units, the conductive grid is divided into a plurality of sensor units for touch detection, the grounding units are insulated and isolated from the conductive grid and are grounded through a flexible circuit, and integration of touch and electromagnetic shielding functions is realized. According to the design, the grounding unit is integrated on the sensor layer, a traditional independent shielding layer is omitted, and the module thickness is effectively reduced; the grounding units distributed periodically form a local shielding area, so that touch drift caused by electromagnetic interference is effectively inhibited; the flexible circuit is directly grounded to shorten a signal transmission path and reduce crosstalk. The anti-interference pressure sensor is compact in structure and has anti-interference and pressure detection functions.

Description

Technical Field

[0001] This utility model relates to the field of touch screen technology, and in particular to a touch screen module. Background Technology

[0002] Existing capacitive touchscreen modules typically consist of a cover glass, a sensor layer, a control chip, and flexible circuitry. The sensor layer often uses indium tin oxide (ITO) or a metal mesh as the conductive material, bonded to the cover glass with optical adhesive to form the touch sensing area. Flexible circuitry is positioned at the edge of the sensor layer to transmit detection signals. To achieve electromagnetic interference (EMI) protection, traditional solutions require an additional independent shielding layer (such as copper foil or a conductive film) outside the sensor layer, isolated from the sensor by an insulating layer, and finally grounded via the flexible circuitry.

[0003] The core defect of existing touch screen modules lies in the physical separation of the electromagnetic shielding structure and the touch sensor: the introduction of an independent shielding layer forces the module to increase in thickness, and additional patterning of the shielding layer and bonding of the insulating layer are required, which significantly increases production costs; more importantly, the leads between the shielding layer and the sensor need to be routed in layers through flexible circuits, and long-distance parallel transmission aggravates signal crosstalk, which can easily cause touch coordinate drift or false triggering in complex electromagnetic environments. Utility Model Content

[0004] The main purpose of this invention is to provide a touch screen module that aims to solve the problems of touch drift and false triggering under electromagnetic interference environments.

[0005] To achieve the above objectives, this utility model proposes a touch screen module, including a cover glass, a sensor layer, a control chip, and a flexible circuit. The cover glass is fixedly connected to the sensor layer, and the flexible circuit is located at the edge of the sensor layer. The sensor layer includes a conductive grid and grounding units periodically distributed in the conductive grid. The conductive grid divides into several sensor units, and the grounding units are insulated from the conductive grid and grounded through the conductive path of the flexible circuit, thereby achieving integrated electromagnetic shielding and touch detection functions.

[0006] In one possible implementation, the grounding unit is distributed at a density of one grounding unit for every 5×5 sensor units, and the area of ​​the grounding unit is 1.5 to 2 times the area of ​​the adjacent sensor unit.

[0007] In one possible implementation, the conductive mesh is composed of silver nanowires with a mesh spacing of 50–500 μm.

[0008] In one possible implementation, the sensor layer has an elastic support layer on the side opposite to the cover glass. The surface of the elastic support layer has a micro-protrusion array. When touched, the external force causes the micro-protrusion array to deform, resulting in a change in the distance between the sensor layer and the elastic support layer.

[0009] In one possible implementation, the micro-bump array has a unit diameter of 30–100 μm and a height of 5–20 μm.

[0010] The working principle and beneficial effects of this utility model are as follows:

[0011] This utility model integrates periodically distributed grounding units and conductive grids into the sensor layer, and utilizes flexible circuit conductive paths to directly achieve the electromagnetic shielding function of the grounding units. This eliminates the need for additional patterning and insulation bonding processes required by traditional independent shielding layers, significantly reducing module thickness and production costs. Simultaneously, by leveraging the co-layer layout of the grounding units and touch detection circuits, the need for layered wiring between the shielding layer and the sensor is eliminated, shortening the signal transmission path and avoiding signal crosstalk caused by long-distance parallel wiring. Ultimately, through the structural integration of embedded regional shielding and touch functionality within the sensor layer, the problems of touch coordinate drift and false triggering in complex electromagnetic environments are solved. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the structure of this utility model;

[0014] The following are the symbols in the attached diagram: 1. Cover glass; 2. Sensor layer; 3. Elastic support layer.

[0015] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0016] 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.

[0017] like Figure 1As shown, this embodiment proposes a touch screen module, including a cover glass 1, a sensor layer 2, a control chip, and a flexible circuit. The cover glass 1 is fixedly connected to the sensor layer 2. The flexible circuit is located at the edge of the sensor layer 2. The sensor layer 2 includes a conductive grid and grounding units periodically distributed in the conductive grid. The conductive grid divides into several sensor units. The grounding units are insulated from the conductive grid and grounded through the conductive path of the flexible circuit, thereby realizing the integrated electromagnetic shielding function and touch detection function.

[0018] The cover glass 1, serving as the outer protective structure of the touchscreen module, directly withstands the physical contact and environmental stress during touch operations, while also providing an optical interface. The cover glass 1 should be made of a high-hardness material (such as chemically strengthened glass) to resist scratches and impacts, and its surface should be coated with an anti-fingerprint film to maintain smooth touch operation. During touch operations, the signal is transmitted through the cover glass 1 to the sensor layer 2 below. The cover glass 1 and sensor layer 2 are fully bonded together with optical adhesive to avoid light refraction loss caused by air gaps, while also fixing the position of sensor layer 2 to prevent displacement. Sensor layer 2 uses a conductive grid to detect touch position and utilizes periodically distributed grounding units instead of a traditional independent shielding layer, integrating electromagnetic shielding functionality. The conductive grid forms a capacitive sensing array; during touch, the finger charge causes changes in the capacitance of the grid nodes. The grounding units are insulated from the conductive grid, forming a local Faraday cage through flexible circuit grounding to absorb external electromagnetic interference and prevent coupling with touch signals. The flexible circuit serves as the signal transmission channel between sensor layer 2 and the control chip, and also provides the electrical connection function for the grounding units. The flexible circuit transmits the touch signals from the conductive mesh to the control chip and simultaneously connects the grounding unit to the system ground terminal, forming a low-impedance noise discharge path to block the propagation of electromagnetic interference to sensor layer 2. The control chip is used to analyze the signals from sensor layer 2 to realize touch coordinate calculation and noise suppression. After receiving the original capacitance signal from the conductive mesh, the control chip extracts the effective touch signal through a differential amplifier circuit, dynamically filters out environmental interference by combining it with noise monitoring data from the grounding unit, and finally outputs accurate touch coordinates.

[0019] In this embodiment, the distribution density of the grounding unit is 1 grounding unit inserted for every 5×5 sensor units, and the area of ​​the grounding unit is 1.5 to 2 times the area of ​​the adjacent sensor unit; the conductive grid is composed of silver nanowires with a grid spacing of 50 to 500 μm.

[0020] By periodically inserting grounding units, a local electromagnetic shielding area is formed, suppressing environmental noise interference with touch signals. A 5×5 density (1:25 ratio) balances shielding coverage with the proportion of the effective touch area, avoiding an increase in touch blind spots due to excessively dense grounding units. Simultaneously, this density is compatible with the precision of mainstream photolithography or printing processes, preventing a decrease in processing yield due to excessively small units. A grounding unit area 1.5 to 2 times the area of ​​adjacent sensor units effectively enhances local electric field absorption and improves electromagnetic shielding efficiency. Increasing the area increases the coupling capacitance between the grounding unit and the interference source, accelerating noise discharge. An excessively large area may compress the spacing between adjacent sensor units; a range of 1.5 to 2 times ensures shielding capability is compatible with touch resolution. Preferably, the area of ​​the grounding unit is 1.8 times the area of ​​adjacent sensor units. Grounding units larger than 1.8 times the area of ​​adjacent sensor units achieve the optimal balance between shielding efficiency and touch spacing loss, resulting in the best overall cost-effectiveness. By using silver nanowires instead of traditional ITO materials, low-impedance touch signal transmission is achieved through a highly conductive metal mesh. Silver nanowires have low sheet resistance, effectively improving the signal-to-noise ratio. The grid spacing determines the balance between touch detection resolution and transmittance. A grid spacing of 50–500 μm can achieve high touch sampling and high transmittance. Preferably, a grid spacing of 200 μm is used, as this balances touch sampling and transmittance, ensuring balanced performance.

[0021] In this embodiment, an elastic support layer 3 is provided on the side of the sensor layer 2 away from the cover glass 1. A micro-protrusion array is provided on the surface of the elastic support layer 3. When touched, the external force causes the micro-protrusion array to deform, resulting in a change in the distance between the sensor layer 2 and the elastic support layer 3. The unit diameter of the micro-protrusion array is 30-100μm and the height is 5-20μm.

[0022] The elastic support layer 3 provides physical feedback for touch pressure, converting external force into a change in distance between the sensor layer 2 and the support layer through elastic deformation. This enhances touch stability and prevents the sensor layer 2 from shifting or vibrating due to external forces. The elastic support layer 3 improves the accuracy of touch pressure detection, making the touch signal more stable. The micro-bump array provides local deformation during touch, making the distance change between the sensor layer 2 and the elastic support layer 3 more obvious, facilitating the detection of pressure gradients. The micro-bump array improves the linearity of touch response, making pressure detection more consistent with actual touch. A micro-bump array with a unit diameter of 30–100 μm maintains high local accuracy of pressure detection while enhancing touch stability. A micro-bump array with a unit diameter of 80 μm is preferred, as it balances sensitivity and stability, making it suitable for finger touch. A micro-bump array with a height of 5–20 μm provides more obvious pressure feedback and ensures smooth touch. Preferably, an array of micro-protrusions with a height of 8μm is used, which is suitable for light touch operation (such as mobile phone screen) and can effectively reduce the probability of accidental touch.

[0023] The working principle of the elastic support layer 3 is to achieve touch pressure detection through the elastic deformation of the micro-protrusion array. When there is no touch, the micro-protrusions maintain a fixed distance between the sensor layer 2 and the support layer, forming a reference capacitance value. When a finger presses, the micro-protrusions deform under pressure, causing the distance to decrease, which increases the capacitance value between the sensor layer 2 and the support layer. By detecting the amount and rate of change of this capacitance, the control chip can calculate the touch pressure and distinguish between real touch and environmental interference (such as water droplets), ultimately achieving high-precision pressure touch and anti-mistouch function.

[0024] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this application, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0025] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A touch screen module, comprising a cover glass (1), a sensor layer (2), a control chip and a flexible circuit, the cover glass (1) is fixedly connected with the sensor layer (2), the flexible circuit is located at the edge of the sensor layer (2), characterized in that, the cover glass (1) is provided with a plurality of through holes (3) arranged in a matrix, the through holes (3) are filled with a transparent conductive material (4), the transparent conductive material (4) is connected with the sensor layer (2) and the flexible circuit, and the transparent conductive material (4) is connected with the sensor layer (2) and the flexible circuit. The sensor layer (2) includes a conductive grid and grounding units periodically distributed in the conductive grid. The conductive grid divides into several sensor units. The grounding units are insulated from the conductive grid and grounded through the conductive path of the flexible circuit, thereby realizing the integrated electromagnetic shielding function and touch detection function.

2. A touchscreen module according to claim 1, characterized in that, The grounding unit is distributed at a density of one grounding unit for every 5×5 sensor units, and the area of ​​the grounding unit is 1.5 to 2 times the area of ​​the adjacent sensor unit.

3. A touchscreen module according to claim 1, characterized in that, The conductive mesh is composed of silver nanowires, and the mesh spacing is 50–500 μm.

4. A touchscreen module according to claim 1, characterized in that, The sensor layer (2) has an elastic support layer (3) on the side away from the cover glass (1). The surface of the elastic support layer (3) is provided with a micro-protrusion array. When touched, the external force causes the micro-protrusion array to deform, resulting in a change in the distance between the sensor layer (2) and the elastic support layer (3).

5. A touchscreen module according to claim 4, characterized in that, The micro-protrusion array has a unit diameter of 30–100 μm and a height of 5–20 μm.

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