Explosion-proof film for touch screens

Abstract

The invention relates to an explosion-proof film for touch screens and belongs to the technical field of peripheral accessories of electronic products. The explosion-proof film for touch screens comprises a transparent glass cover plate and a film, the glass cover plate includes a planar portion located in a middle region of the glass cover plate, an arc portion is formed by hot bending of glass around the planar portion, the periphery of a low surface of the glass cover plate is printed with a black ink layer covering the arc portion, a region, in which the black ink layer is not printed, in the middle of the glass cover plate is a window region for viewing screen display contents, the film is bonded to the lower surface of the glass cover plate and the peripheral edge of the film is overlapped on the black ink layer, the outer edge of the film is departed from the inner edge of the arc portion by a certain distance, thus a cavity is formed between the film and the arc portion and is filled with a foamed buffer cushion which can produce plastic deformation after being pressed, the outer edge of the foamed buffer cushion is slightly lower than or flush with the inner edge of the arc portion, and the inner edge of the foamed buffer cushion is slightly lower than or flush with the outer edge of the film. The explosion-proof film for the touch screens and the touch screens have high degree of adhesion, no visible splicing line exists after bonding, scratch resistance and abrasion resistance are achieved, and cleaning is convenient.

Description

Technical field [0001] The invention relates to the technical field of peripheral accessories of electronic products, in particular to an explosion-proof film for a touch screen. Background technique [0002] The early anti-explosion films for external screens were mostly made of PET or PC film. Due to the poor wear resistance of plastic materials (even if the surface is hardened, the wear resistance is still not ideal), it is prone to scratches and has basically been eliminated. Tempered glass has relatively better scratch and wear resistance, and has become the mainstream material for explosion-proof membranes. [0003] At present, the explosion-proof membrane using tempered glass is mainly divided into three stages in the process of marketization. The first stage is a pure plane structure. The explosion-proof film is a whole piece of plane glass. The glass has earpiece holes and sensor holes. Because the outer screens of current smartphones mostly use 2.5D curved glass (that is...

AI Technical Summary

Problems solved by technology

The first stage is a pure planar structure, and the explosion-proof film is a whole piece of flat glass with earpiece holes and sensor holes on the glass. Since the outer screens of current smartphones mostly use 2.5D curved glass (that is, there are holes on the periphery of the glass rounded corners), the pure flat explosion-proof film cannot cover the arc-shaped rounded corners of the outer screen (that is, the explosion-proof film cannot fully cover the touch screen), and the overall visual effect will be affected after the film is applied. yuan / piece)

The second stage is a 2.5D curved glass explosion-proof film that is bent into an arc around it. This type of explosion-proof film is made of all glass. It has the following defects in actual use: 1. Because the arc-shaped rounded corners of the smartphone are only In order to ensure the comfort of the grip, the brand allows the foundry to have a large manufacturing error, which leads to the fact that the arc fillets of the same model of mobile phones sold on the market are not all consistent, so they often encounter the same explosion-proof film. This mobile phone fits perfectly, but another mobile phone of the same model does not fit perfectly

2. In the same mobile phone, the rounded corners on the four sides of the outer screen are not exactly the same. It is also a common situation that the rounded corners of one side cannot be completely fitted

3. The manufacturing error of the explosion-proof film itself (such as the manufacturing error of the glass during hot bending and the change in the curvature of the arc part caused by the tempering process in the furnace) is superimposed on the manufacturing error of the outer screen of the mobile phone, which further leads to the explosion-proof film. Poor fit of curved and rounded corners

Because this kind of explosion-proof film is made of all glass and cannot fit well in the arc-shaped rounded corners, it is very easy to break the arc-shaped part during daily use due to pressure or impact, and its price is not high. Cheap (generally 30-40 yuan / piece), the current market share is already low

In the third stage (that is, the current stage), explosion-proof membranes with splicing structures (such as soft-edge explosion-proof membranes) have been developed. The middle plane part of this type of explosion-proof membrane is made of tempered glass, and the surrounding arc parts (generally referred to as "arc-shaped frames" in the industry) Plastic material (such as PC, PET, etc.) is used. Since the curved frame is made of plastic material, it has better deformation ability. Compared with the all-glass explosion-proof film, it can fit the touch screen better. It has become a mainstream product in the market (the price ranges from 30 to 100 yuan), but due to the poor wear resistance of plastic, it will form on the curved frame after a period of use. obvious scratches

In order to solve the problem that the plastic frame is not wear-resistant and splicing white lines, some manufacturers of explosion-proof membranes have added short glass fibers to the plastic to improve the dimensional stability and wear resistance of the frame, and at the same time improved the splicing structure to an overlapping structure. By leaving a step on the side of the black arc-shaped frame A, and then lapping the glass sheet B under the step (that is, a part of the arc-shaped frame rests on the upper surface of the glass sheet), looking from top to bottom , the contour line of the glass sheet B is covered by the black curved frame A, thereby completely avoiding the appearance of white stitching lines (see the attached cross-sectional structure figure 1 shown), but this brings other problems. Firstly, this will lead to a significant increase in cost (the explosion-proof price of this lap joint structure basically reaches more than 90 yuan / piece), and secondly, due to the curved frame A Higher than glass sheet B, it is easy to accumulate dust at the overlapping joint and it is not easy to clean

Finally, most of the above-mentioned explosion-proof films using tempered glass will be coated with a layer of AB glue on the bonding surface. The side of the AB glue and the tempered glass is OCA optical glue, and the side of the touch screen is silica gel. The van der Waals force between the silicone surface and the smooth glass of the touch screen realizes adsorption and bonding. In order to improve the self-adsorption of the explosion-proof film during bonding, the silicone bonding surface of some explosion-proof films has been electrostatically treated, but due to the AB glue pole Thin and its back is made of glass (AB glue is attached to the glass sheet B of the explosion-proof film), and the improvement of self-adsorption is not obvious for electrostatic treatment (it is still necessary to press by hand to help the adsorption during the film sticking process)

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