A transparent pressure-sensitive touch screen

Abstract

This invention discloses a transparent pressure-sensitive touchscreen, which includes a protective glass layer, a transparent pressure-sensing layer, a capacitive sensing layer, a display panel, and a main control module, stacked and fixed from top to bottom. The outer surface of the protective glass layer is covered with a hydrophobic transparent film. The transparent pressure-sensing layer is composed of polydimethylsiloxane doped with silver nanoparticles. The capacitive sensing layer includes a first transparent conductive film and a second transparent conductive film arranged in parallel and spaced apart. The surface of the first transparent conductive film is etched with conductive lines extending in a first direction, and the surface of the second transparent conductive film is etched with conductive lines extending in a second direction. By adopting a dual-circuit collaborative working mode that detects pressure first and then locates coordinates, this invention enables the touchscreen to first detect the resistance change of the transparent pressure-sensing layer. This fundamentally solves the problem that existing capacitive screens rely solely on capacitance changes to determine touch, leading to misoperation when a finger approaches or is accidentally touched.

Description

Technical Field

[0001] This utility model relates to the technical field of touch screens, specifically to a transparent pressure-sensitive touch screen. Background Technology

[0002] Capacitive touchscreens determine touch location by detecting changes in capacitance between two orthogonally arranged transparent electrodes. When a user touches the screen with their finger, the human body's electric field creates a coupling capacitor between the finger and the screen surface. For high-frequency currents, the capacitor acts as a direct conductor, causing the finger to draw a small current from the contact point. This current flows out from electrodes at the four corners of the touchscreen, and the current flowing through these four electrodes is proportional to the distance from the finger to the corner. The controller calculates the precise ratio of these four currents to determine the touch point's location.

[0003] Currently available capacitive screens cannot distinguish between unintentional touches and intentional operations. When a finger approaches the capacitive screen, it can cause changes in capacitance, resulting in jump points. If the capacitance detection threshold is increased, users with smaller fingers may not be able to reach the detection threshold when touching the screen, leading to disconnections. Utility Model Content

[0004] The purpose of this invention is to provide a transparent pressure-sensitive touchscreen to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a transparent pressure-sensitive touch screen, the touch screen comprising a protective glass layer, a transparent pressure-sensitive layer, a capacitive sensing layer, a display panel, and a main control module, which are stacked and fixed together from top to bottom;

[0006] The outer surface of the protective glass layer is covered with a hydrophobic transparent film. The transparent pressure sensing layer is composed of polydimethylsiloxane doped with silver nanoparticles. The capacitance sensing layer includes a first transparent conductive film and a second transparent conductive film arranged in parallel and spaced apart. The surface of the first transparent conductive film is etched with conductive lines extending in a first direction, and the surface of the second transparent conductive film is etched with conductive lines extending in a second direction. The first direction and the second direction are perpendicular to each other. The main control module is electrically connected to the conductive lines of the capacitance sensing layer and the transparent pressure sensing layer through a flexible circuit board.

[0007] A pressure conduction micro-bump layer is provided between the transparent pressure sensing layer and the capacitive sensing layer, and the pressure conduction micro-bump layer is a transparent insulating layer.

[0008] Preferably, the pressure-conducting microbump layer is a hemispherical transparent silica microbump.

[0009] Preferably, a transparent insulating spacer layer is provided between the first transparent conductive film and the second transparent conductive film, and the transparent insulating spacer layer has through holes corresponding to the positions of the pressure transmission micro-bump layer.

[0010] Preferably, the display panel is a liquid crystal display module, and the display area coincides with the projection area of ​​the capacitive sensing layer. A metal shielding layer is provided on the back of the display panel, and the metal shielding layer is connected to the grounding terminal of the main control module through a grounding wire.

[0011] Preferably, the main control module includes a capacitor signal processing circuit and a pressure signal processing circuit. The capacitor signal processing circuit is connected to the conductive lines of the first transparent conductive film and the second transparent conductive film. The pressure signal processing circuit is connected to both ends of the transparent pressure sensing layer through two silver nanowire wires.

[0012] Preferably, the protective glass layer and the transparent pressure-sensing layer are bonded together with an optically transparent adhesive, and the hydrophobic transparent film and the protective glass layer adopt a hot-melt composite structure.

[0013] Preferably, the hydrophobic transparent film is a fluorosilicone resin coating.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] 1. By adopting a dual-circuit collaborative working mode that first detects pressure and then locates coordinates, this utility model enables the touch screen to first detect the resistance change of the transparent pressure sensing layer. This fundamentally solves the problem that existing capacitive screens rely solely on capacitance changes to determine touch control, leading to misoperation when a finger approaches or is accidentally touched.

[0016] 2. This utility model improves the sensitivity of pressure detection by focusing finger pressure to a local area of ​​the capacitive sensing layer through the design of the pressure transmission micro-bump layer. At the same time, the hemispherical design avoids scratching the underlying conductive film, and the transparent material maintains the optical uniformity between layers. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the stacked structure of the transparent pressure-sensitive touch screen of this utility model.

[0018] Figure 2 This is a schematic diagram of the structure of the capacitive sensing layer of this utility model.

[0019] Figure 3 This is a schematic diagram of the structure of the display panel of this utility model.

[0020] In the figure: 1. Protective glass layer; 11. Hydrophobic transparent film; 2. Transparent pressure sensing layer; 3. Capacitive sensing layer; 31. First transparent conductive film; 32. Second transparent conductive film; 33. Transparent insulating spacer layer; 34. Through hole; 4. Display panel; 41. Metal shielding layer; 5. Main control module; 6. Pressure conduction micro-bump layer. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Please see Figures 1 to 3 This utility model provides a technical solution: a transparent pressure-sensitive touch screen, the touch screen comprising a protective glass layer 1, a transparent pressure-sensitive layer 2, a capacitive sensing layer 3, a display panel 4, and a main control module 5, which are stacked and fixed from top to bottom;

[0023] The outer surface of the protective glass layer 1 is covered with a hydrophobic transparent film 11, which is a fluorosilicone resin coating. The transparent pressure sensing layer 2 is composed of polydimethylsiloxane doped with nano-silver particles. The protective glass layer 1 and the transparent pressure sensing layer 2 are bonded together with optical transparent adhesive.

[0024] The hydrophobic transparent film 11 and the protective glass layer 1 adopt a hot-melt composite structure. The superhydrophobic properties of the hydrophobic film 11 can repel water droplets and oil stains, and improve the smoothness of touch. The fluorosilicone resin and the glass layer 1 form a nanoscale intercalation layer through the hot-melt composite structure, which enhances the interfacial bonding force and prevents the film layer from peeling off.

[0025] The transparent pressure-sensing layer 2 uses nano-silver to form a conductive network. When pressure is applied, the particle spacing decreases, resulting in a decrease in resistance. The flexibility of the polydimethylsiloxane ensures that the deformation recovers after multiple presses.

[0026] The capacitive sensing layer 3 includes a first transparent conductive film 31 and a second transparent conductive film 32 arranged in parallel and spaced apart. The surface of the first transparent conductive film 31 is etched with conductive lines extending in a first direction, and the surface of the second transparent conductive film 32 is etched with conductive lines extending in a second direction, and the first direction and the second direction are perpendicular to each other.

[0027] Among them, a pressure conduction microbump layer 6 is provided between the transparent pressure sensing layer 2 and the capacitive sensing layer 3. The pressure conduction microbump layer 6 is made of transparent insulating material. The pressure conduction microbump layer 6 is a hemispherical transparent silicon dioxide microbump, which focuses and conducts finger pressure to a local area of ​​the capacitive sensing layer 3, thereby improving the pressure detection sensitivity. The hemispherical design avoids scratching the underlying conductive film and maintains the optical uniformity between layers.

[0028] By applying pressure and capacitance signals to the touch panel with a finger, the polydimethylsiloxane doped with silver nanoparticles in the transparent pressure sensing layer 2 reduces its resistance after receiving pressure deformation, resulting in an increase in capacitance change. External capacitance changes cause changes in capacitance nodes on the transparent conductive film. By measuring these changes, the main control panel can determine the touch position and display it through the display panel 4.

[0029] A transparent insulating spacer layer 33 is provided between the first transparent conductive film 31 and the second transparent conductive film 32. The transparent insulating spacer layer 33 has through holes 34 corresponding to the positions of the pressure conduction micro-bump layer 6. The through holes 34 of the transparent insulating spacer layer 33 allow the pressure of the pressure conduction micro-bump layer 6 to be transmitted without loss, avoiding signal attenuation. The transparent insulating spacer layer 33 prevents short circuits between lines and ensures the stability of capacitance detection.

[0030] The display panel 4 is a liquid crystal display module, and the display area coincides with the projection area of ​​the capacitive sensing layer 3. A metal shielding layer 41 is provided on the back of the display panel 4. The metal shielding layer 41 is connected to the grounding terminal of the main control module 5 through a grounding wire. The metal shielding layer 41 and the grounding wire on the back of the display panel 4 suppress electromagnetic interference.

[0031] The main control module 5 is fixed on the non-display area on the back of the display panel 4. The main control module 5 is electrically connected to the conductive lines of the capacitive sensing layer 3 and the transparent pressure sensing layer 2 through a flexible circuit board. The main control module 5 includes a capacitive signal processing circuit and a pressure signal processing circuit. The capacitive signal processing circuit is connected to the conductive lines of the first transparent conductive film 31 and the second transparent conductive film 32. The pressure signal processing circuit is connected to both ends of the transparent pressure sensing layer 2 through two silver nanowires. The silver nanowires are used to improve the sensitivity of the pressure signal.

[0032] The capacitance signal processing circuit scans the capacitance change of the X / Y line and outputs the touch coordinates; the pressure signal processing circuit injects a constant current into the transparent pressure sensing layer 2 and detects the resistance change value; the dual circuits work together to achieve the effect of first detecting pressure and then locating coordinates, thus shielding against accidental floating touches.

[0033] In actual use, when a finger presses on the protective glass layer 1, the pressure is transmitted to the transparent pressure sensing layer 2 through the optical transparent adhesive. The polydimethylsiloxane in the transparent pressure sensing layer 2 reduces its resistance after being deformed by the pressure. The pressure is focused through the pressure conduction micro-bump layer 6 and penetrates the through hole 34 of the transparent insulating spacer layer 33, acting on the capacitive sensing layer 3. The pressure signal processing circuit detects the decrease in resistance and determines that it is a valid press. The capacitive signal processing circuit scans the X / Y line to locate the node with the largest change in capacitance. The main control module 5 synchronously outputs the coordinates and pressure value.

[0034] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A transparent pressure sensitive touch screen, characterized by: The touch screen includes a protective glass layer (1), a transparent pressure sensing layer (2), a capacitive sensing layer (3), a display panel (4), and a main control module (5) that are stacked and fixed from top to bottom. The outer surface of the protective glass layer (1) is covered with a hydrophobic transparent film (11), the transparent pressure sensing layer (2) is composed of polydimethylsiloxane doped with nano-silver particles, the capacitance sensing layer (3) includes a first transparent conductive film (31) and a second transparent conductive film (32) arranged in parallel intervals. The surface of the first transparent conductive film (31) is etched with conductive lines extending in a first direction, and the surface of the second transparent conductive film (32) is etched with conductive lines extending in a second direction. The first direction and the second direction are perpendicular to each other. The main control module (5) is electrically connected to the conductive lines of the capacitance sensing layer (3) and the transparent pressure sensing layer (2) through a flexible circuit board. Among them, a pressure conduction micro-bump layer (6) is provided between the transparent pressure sensing layer (2) and the capacitive sensing layer (3), and the pressure conduction micro-bump layer (6) is a transparent insulating layer.

2. The transparent pressure sensitive touch screen according to claim 1, wherein: The pressure-conducting microbump layer (6) is a hemispherical transparent silica microbump.

3. The transparent pressure sensitive touch screen according to claim 1, wherein: A transparent insulating spacer layer (33) is provided between the first transparent conductive film (31) and the second transparent conductive film (32), and the transparent insulating spacer layer (33) has through holes (34) corresponding to the positions of the pressure transmission micro-bump layer (6).

4. The transparent pressure sensitive touch screen according to claim 1, wherein: The display panel (4) is a liquid crystal display module, and the display area coincides with the projection area of ​​the capacitive sensing layer (3). A metal shielding layer (41) is provided on the back of the display panel (4), and the metal shielding layer (41) is connected to the grounding terminal of the main control module (5) through a grounding wire.

5. A transparent pressure-sensitive touchscreen according to claim 1, characterized in that: The main control module (5) includes a capacitor signal processing circuit and a pressure signal processing circuit. The capacitor signal processing circuit is connected to the conductive lines of the first transparent conductive film (31) and the second transparent conductive film (32). The pressure signal processing circuit is connected to both ends of the transparent pressure sensing layer (2) through two silver nanowire wires.

6. A transparent pressure-sensitive touchscreen according to claim 1, characterized in that: The protective glass layer (1) and the transparent pressure sensing layer (2) are bonded together by optically transparent adhesive, and the hydrophobic transparent film (11) and the protective glass layer (1) adopt a hot-melt composite structure.

7. A transparent pressure-sensitive touchscreen according to claim 1, characterized in that: The hydrophobic transparent film (11) is a fluorosilicone resin coating.

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