Window protective film, cover plate and display device

Abstract

This invention relates to a window protective film, a cover plate, and a display device. The window protective film includes a central protective portion and an edge overlapping portion, with the edge overlapping portion located outside the central protective portion. The thickness of the outer edge of the edge overlapping portion away from the central protective portion is less than the thickness of the central protective portion. Because the thickness of the outer edge of the edge overlapping portion away from the central protective portion is less than the thickness of the central protective portion, the height of the ink layer formed at the edge overlapping portion is effectively reduced. This, in turn, reduces the height of the ink protrusion formed after removing the window protective film, ultimately effectively reducing the number of air bubbles generated after the cover plate is applied, and improving the production yield of the display device. At the same time, since the thickness of the central protective portion is not reduced, the overall structural strength of the window protective film is not affected.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a window protective film, a cover plate and a display device. Background Art

[0002] With the guidance of market trends and the gradual improvement of people's aesthetic requirements for the appearance of smart devices, the screen-to-body ratio and appearance of the display substrate of smart devices have become one of the key factors that the display industry pays attention to. With the development of 3D curved glass hot bending technology, the left and right sides of the glass cover (CoverGlass, CG) and even the top and bottom sides can be designed into arcs, so that the product can achieve an ultra-high screen-to-body ratio and a narrow frame design, which further increases the visible area.

[0003] For cover plates with curved edges, in order to prevent light from penetrating the edges of the cover plates and exposing the components underneath the cover plates, a pad printing ink layer and a spraying ink layer are usually provided in the non-window area of ​​the cover plates. Figure 1 and Figure 2 As shown, before forming the spray ink layer 180 , a window protection film 160 is usually covered on the pad printing ink layer 140 to protect the window area of ​​the cover plate 120 to prevent ink from falling on the window area. After forming the spray ink layer 180 , the window protection film 160 is torn off.

[0004] However, since the window protection film 160 has a certain thickness, when the window protection film 160 is torn off, the sprayed ink layer 180 is broken, and ink protrusions are formed at the broken position of the sprayed ink layer 180. The existence of the ink protrusions causes bubbles to be generated after the cover plate 120 is bonded, thereby reducing the production yield of the display substrate. Summary of the invention

[0005] Based on this, the present invention provides a window protective film, a cover plate and a display device to solve the problem of ink protrusions formed after the protective film is torn off, causing bubbles to be generated during the lamination of the cover plate.

[0006] According to one aspect of the present application, a window protection film is provided, the window protection film comprising a middle protection portion and an edge overlap portion, the edge overlap portion being located outside the middle protection portion;

[0007] Wherein, the thickness of the outer edge of the edge overlapping portion away from the middle protecting portion is smaller than the thickness of the middle protecting portion.

[0008] In the above-mentioned window protection film, since the thickness of the outer edge of the edge overlap portion away from the middle protection portion is less than the thickness of the middle protection portion, the height of the sprayed ink layer formed on the edge overlap portion is effectively reduced, thereby reducing the height of the ink protrusion formed after the window protection film is torn off, and finally effectively reducing the number of bubbles generated after the cover plate is attached, thereby improving the production yield rate of the display device. At the same time, since the thickness of the middle protection portion is not reduced, the overall structural strength of the window protection film will not be affected.

[0009] In one embodiment, the edge overlap portion circumferentially surrounds the outer side of the middle protection portion.

[0010] In one embodiment, the maximum thickness of the edge overlapping portion is not greater than the thickness of the intermediate protecting portion.

[0011] In one embodiment, the thickness of the edge overlap portion gradually decreases from a side connected to the middle protection portion to a side away from the middle protection portion.

[0012] In one embodiment, the edge overlap portion is formed by thermoforming.

[0013] According to one aspect of the present application, there is provided a cover plate, the cover plate comprising a window portion and a non-window portion circumferentially surrounding the window portion, a receiving groove being provided on one side surface of the non-window portion, the receiving groove being located outside the window portion;

[0014] The receiving groove is used to receive the edge overlap portion of the above-mentioned window protection film, and the edge overlap portion is partially received in the receiving groove.

[0015] In one embodiment, the receiving groove circumferentially surrounds the window portion.

[0016] In one embodiment, the depth of the receiving groove gradually increases from a side close to the window portion to a side far from the window portion.

[0017] In one embodiment, the cover plate is provided with a side surface of the receiving groove covering the pad-printed ink layer surrounding the window portion, the edge overlapping portion overlaps the pad-printed ink layer located in the receiving groove, and the edge of the edge overlapping portion away from the middle protective layer is flush with the side surface of the pad-printed ink layer away from the cover plate.

[0018] According to one aspect of the present application, a display device is provided, including a display substrate and the above-mentioned cover plate, wherein the cover plate covers one side of the display substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1It is a schematic diagram of the cross-sectional structure of a cover plate covered with a window protection film in the prior art;

[0020] Figure 2 It is a schematic diagram of the cross-sectional structure of the cover plate after the window protective film is torn off in the prior art;

[0021] Figure 3 A schematic diagram of a top view of a window protection film according to an embodiment of the present invention;

[0022] Figure 4 It is a schematic cross-sectional structure diagram of a cover plate covered with a window protection film according to an embodiment of the present invention;

[0023] Figure 5 A longitudinal cross-sectional view of a window protection film according to an embodiment of the present invention;

[0024] Figure 6 It is a schematic cross-sectional structure diagram of a cover plate covered with a window protection film according to an embodiment of the present invention;

[0025] Figure 7 FIG. 4 is a longitudinal cross-sectional view of a cover plate according to an embodiment of the present invention.

[0026] Description of Figure Numbers:

[0027] 120, cover plate; 140, pad printing ink layer; 160, window protection film; 180, spraying ink layer;

[0028] 210, cover plate; 212, window portion; 214, non-window portion; 2141, receiving groove; 230, pad-printed ink layer; 250, window protection film; 252, intermediate protection portion; 2521, first intermediate surface; 2523, second intermediate surface; 254, edge overlap portion; 2541, connecting groove; 2543, first edge surface; 2545, second edge surface; 2547, side surface; 270, sprayed ink layer. DETAILED DESCRIPTION

[0029] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0030] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0032] In the case of using “including”, “having”, and “comprising” described herein, another component may be added unless a clear limiting term such as “only”, “consisting of”, etc. is used. Unless mentioned otherwise, a term in the singular form may include a plural form and should not be understood as being one in number.

[0033] It should also be understood that when interpreting an element, even if not explicitly described, the element is interpreted as including a range of error, which should be within the acceptable deviation range of the specific value determined by those skilled in the art. For example, "approximately", "approximately" or "substantially" can mean within one or more standard deviations, which are not limited here.

[0034] Furthermore, in the specification, the phrase “plan view schematic diagram” refers to a drawing when a target portion is viewed from above, and the phrase “cross-sectional view schematic diagram” refers to a drawing when a section taken by vertically cutting the target portion is viewed from the side.

[0035] In addition, the drawings are not drawn to a 1:1 scale, and the relative sizes of the elements in the drawings are drawn only as examples and not necessarily according to the true scale.

[0036] like Figure 3 and Figure 4As shown, an embodiment of the present application provides a display device, including a display substrate (not shown) and a cover plate 210 covering one side of the display substrate. The display substrate has a display area and a non-display area, the display area is used to display images or texts, and the non-display area is circumferentially surrounding the outside of the display area for setting metal wiring, etc. The cover plate 210 includes a transparent window portion 212 and a non-transparent non-window portion 214, and the non-window portion 214 is circumferentially surrounding the outside of the window portion 212. When the cover plate 210 is attached to one side of the display substrate, the window portion 212 of the cover plate 210 is arranged corresponding to the display area of ​​the display substrate, and the user can see the image or text displayed in the display area through the window portion 212 of the cover plate 210, and the non-window portion 214 of the cover plate 210 is arranged corresponding to the non-display area of ​​the display substrate to cover the non-display area.

[0037] The cover plate 210 is usually formed of a transparent material such as glass. In order to reduce the light transmittance of the non-window portion 214 to shield the non-display area of ​​the display substrate, a surface of the non-window portion 214 (i.e. Figure 4 The ink layer is made on the surface of the cover plate 210. The ink manufacturing process of the cover plate 210 generally includes the following process: pad printing ink → baking → ultrasonic cleaning → pasting the window protection film 250 → spraying ink → baking → spraying ink → baking → wiping the surface oil → inspecting the surface oil wiping situation → final baking → cleaning → finished product inspection → cleaning → coating AF film.

[0038] In the above process, first, the ink is printed on one side surface of the non-window portion 214 of the cover plate 210 by pad printing, and then the cover plate 210 is baked to solidify the ink, thereby forming a pad printing ink layer 230 surrounding the window portion 212 in the circumferential direction. Since it is difficult to achieve an ideal shielding effect with a single pad printing ink layer 230, it is necessary to continue to cover the pad printing ink layer 230 with ink to further reduce the light transmittance of the non-window portion 214. However, due to the limitation of process precision, it is difficult for the new ink layer to accurately cover the pad printing ink layer 230, so a covering window protection film 250 is used to cover the window portion 212 of the cover plate 210 and the edge of the pad printing ink layer 230 to play a protective role, and then the ink is sprayed to form a sprayed ink layer 270 covering the pad printing ink layer 230 and the window protection film 250.

[0039] When the window protection film 250 is covered on one side surface of the cover plate 210, the window protection film 250 covers the window portion 212 of the cover plate 210 to prevent ink from falling on the window portion 212, and the edge of the window protection film 250 overlaps the pad printing ink layer 230. Afterwards, ink can be sprayed on the cover plate 210 covered with the window protection film 250, and the ink falls on the window protection film 250 and the pad printing ink layer 230 not covered by the window protection film 250 to form a sprayed ink layer 270. Finally, the window protection film 250 is torn off, and the sprayed ink layer 270 on the window protection film 250 is removed along with the window protection film 250, and the remaining sprayed ink layer 270 covers the area on the pad printing ink layer 230 that is not protected by the window protection film 250.

[0040] However, the inventors discovered during research that, since the window protection film 250 has a certain thickness (the current minimum thickness of the window protection film 250 is 0.045 mm), the window protection film 250 protrudes from the pad-printed ink layer 230 in the thickness direction and forms a step difference with the pad-printed ink layer 230, thereby causing the sprayed ink layer 270 at the overlap between the window protection film 250 and the pad-printed ink layer 230 to form an ink protrusion, which causes the cover plate 210 to generate edge bubbles after being bonded to the display substrate, thereby affecting the display effect of the display device and the yield rate of the display device.

[0041] See also Figure 4 In order to solve the above problems, an embodiment of the present invention provides a window protection film 250, which includes a middle protection portion 252 and an edge overlap portion 254. The edge overlap portion 254 is located outside the middle protection portion 252, and the thickness of the outer edge of the edge overlap portion 254 away from the middle protection portion 252 is less than the thickness of the middle protection portion 252. As a preferred embodiment, the edge overlap portion 254 surrounds the outside of the middle protection portion 252 in the circumferential direction. In some other embodiments, the edge overlap portion 254 may be located only outside a portion of the edge of the window protection film 250.

[0042] Before ink is sprayed, the window protection film 250 can be covered on one side surface of the cover plate 210, the middle protection portion 252 of the window protection film 250 is located directly above the window portion 212 of the cover plate 210, and the edge overlap portion 254 of the window protection film 250 is located on the pad printing ink layer 230 on the non-window portion 214. After the spray ink layer 270 is formed, the window protection film 250 can be torn off. Since the thickness of the outer edge of the edge overlap portion 254 away from the middle protection portion 252 is less than the thickness of the middle protection portion 252, the height of the spray ink layer 270 formed on the edge overlap portion 254 is effectively reduced, thereby reducing the height of the ink protrusion formed after the window protection film 250 is torn off, and finally effectively reducing the number of bubbles generated after the cover plate 120 is attached, thereby improving the production yield rate of the display device. At the same time, since the thickness of the middle protection portion 252 is not reduced, the overall structural strength of the window protection film 250 will not be affected.

[0043] Specifically, if combined Figure 5 , the thickness direction of the window protection film 250 is the first direction, and the cross section of the intermediate protection portion 252 perpendicular to the first direction is a rectangle. The intermediate protection portion 252 includes a first intermediate surface 2521 and a second intermediate surface 2523 arranged opposite to each other in the first direction, and the first intermediate surface 2521 and the second intermediate surface 2523 are parallel to each other and perpendicular to the first direction. It can be understood that the shape of the intermediate protection portion 252 is not limited thereto, and the shape of the intermediate protection portion 252 can be set according to the shape of the window portion 212 of the cover plate 210. When the cover plate 210 is used for a wearable device worn on a user, the window portion 212 can have a circular shape like a watch, and the intermediate protection portion 252 is also set to a circular shape accordingly; when the cover plate 210 is used on a vehicle, the window portion 212 can adopt, for example, a circular, polygonal or other shape, and the intermediate protection portion 252 is also set to a circular, polygonal or other shape accordingly.

[0044] The edge overlap portion 254 includes a first edge surface 2543, a second edge surface 2545, and a side surface 2547. The first edge surface 2543 and the second edge surface 2545 are arranged opposite to each other in the first direction, the first edge surface 2543 surrounds the first middle surface 2521 in the circumferential direction and is located in the same plane as the first middle surface 2521, and the second edge surface 2545 surrounds the second middle surface 2523 in the circumferential direction. The side surface 2547 is connected between the first edge surface 2543 and the second edge surface 2545 and is perpendicular to the first edge surface 2543.

[0045] In order to reduce the thickness of the edge overlap portion 254, after the window protection film 250 is covered on the cover plate 210, the edge overlap portion 254 can be heated and a certain pressure can be applied by hot pressing, so that the edge overlap portion 254 is partially thinned, and the maximum thickness of the edge overlap portion 254 is not greater than the thickness of the middle protection portion 252, while the middle protection portion 252 maintains the original thickness. In some other embodiments, the thickness of the edge overlap portion 254 can also be reduced by hot pressing or other methods before the window protection film 250 is covered on the cover plate 210. It can be understood that the method of reducing the thickness of the edge overlap portion 254 is not limited, and different processes can be used as needed.

[0046] Specifically, the thickness of the edge overlap portion 254 gradually decreases from the side connected to the middle protection portion 252 to the side away from the middle protection portion 252, the first edge surface 2543 of the edge overlap portion 254 is perpendicular to the first direction, the second edge surface 2545 of the edge overlap portion 254 extends obliquely toward the side where the first edge surface 2543 is located from the side connected to the second middle surface 2523 to the side away from the second middle surface 2523, and the distance of the second edge surface 2545 relative to the first edge surface 2543 gradually decreases from the side connected to the second middle surface 2523 to the side away from the second middle surface 2523. In this way, the second edge surface 2545 of the edge overlap portion 254 extends smoothly, and the upper surface of the sprayed ink layer 270 formed thereon also extends smoothly.

[0047] In this way, the height of the sprayed ink layer 270 formed on the edge overlap portion 254 relative to the cover plate 210 gradually decreases from the side close to the middle protection portion 252 to the edge away from the middle protection portion 252. Therefore, after tearing off the window protection film 250, the height of the ink protrusion formed at the break of the sprayed ink layer 270 is significantly reduced, thereby reducing the number of edge bubbles generated after the cover plate 210 is attached to the display substrate.

[0048] It can be understood that although the edge overlap portion 254 is thinned in the above embodiment, since the edge overlap portion 254 always has a certain thickness, the edge overlap portion 254 inevitably protrudes from the pad printing ink layer 230, so it is impossible to further reduce the height of the ink protrusion formed after the sprayed ink layer 270 is broken.

[0049] In order to further reduce the height of the ink protrusion formed after the sprayed ink layer 270 is broken, Figure 6 and Figure 7 In some embodiments, a side surface of the non-window portion 214 of the cover plate 210 (ie Figure 6The upper surface of the cover plate 210 is provided with a receiving groove 2141, which is located outside the window portion 212. The receiving groove 2141 is used to accommodate the edge overlap portion 254 of the window protection film 250. Preferably, the receiving groove 2141 is arranged around the window portion 212 in the circumferential direction. In some other embodiments, the receiving groove 2141 may also be located only outside a portion of the edge of the window portion 212. When the window protection film 250 covers the side surface of the cover plate 210 provided with the receiving groove 2141, the edge overlap portion 254 of the window protection film 250 is partially accommodated in the receiving groove 2141, thereby reducing the height difference between the second edge surface 2545 and the upper surface of the pad printing ink layer 230 located in the circumferential direction of the receiving groove 2141, further reducing the height of the ink protrusion, and further reducing the edge bubbles formed after the cover plate 210 is bonded to the display substrate.

[0050] Specifically, the receiving groove 2141 has a receiving groove bottom wall, which is an inclined extending plane, one side of the receiving groove bottom wall is connected to the window portion 212, and the receiving groove bottom wall extends obliquely from the side connected to the window portion 212 toward the direction away from the window portion 212, and the distance of the receiving groove bottom wall relative to the surface of the side of the cover plate 210 where the receiving groove 2141 is not provided is gradually reduced from the side close to the window portion 212 to the side away from the window portion 212, and the depth of the receiving groove 2141 is gradually increased from the side close to the window portion 212 to the side away from the window portion 212. In this way, the edge overlap portion 254 of the window protection film 250 located on the cover plate 210 extends obliquely along the receiving groove bottom wall toward the side of the cover plate 210 where the receiving groove 2141 is not provided, thereby further reducing the height of the ink protrusion formed by the sprayed ink layer 270 after the fracture.

[0051] When the window protection film 250 is covered on the cover plate 210 on which the pad-printed ink layer 230 is formed, the edge of the edge overlap portion 254 on one side away from the middle protection portion 252 is lower than or flush with the upper surface of the pad-printed ink layer 230 on the cover plate 210 where the receiving groove 2141 is not provided, thereby effectively reducing the height of the ink protrusion formed by the sprayed ink layer 270 after it is broken, and further significantly reducing the edge bubbles between the cover plate 210 and the display substrate.

[0052] Preferably, after the window protection film 250 is covered on the cover plate 210 with the pad-printed ink layer 230 formed thereon, the edge of the edge overlap portion 254 of the window protection film 250 away from the middle protection portion 252 is flush with the upper surface of the pad-printed ink layer 30 away from the cover plate 210 .

[0053] In some embodiments, the width of the receiving groove 2141 is 1 mm-10 mm. It is understood that the width and depth of the receiving groove 2141 are not limited and can be set as needed to meet different requirements.

[0054] The above-mentioned window protection film 250, cover plate 210 and display device can effectively reduce the height of the ink protrusion formed at the broken position of the sprayed ink layer 270 by providing a thinned edge overlap portion 254 in the window protection film 250 and opening a receiving groove 2141 on the cover plate 210, thereby effectively controlling the generation of edge bubbles after the cover plate 210 and the display substrate are attached, thereby improving the yield rate of the display device.

[0055] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0056] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A window protective film, characterized in that: The window protection film comprises a middle protection portion and an edge overlap portion, wherein the edge overlap portion is located outside the middle protection portion; Among them, the edge overlap portion is hot-pressed formed, the maximum thickness of the edge overlap portion is not greater than the thickness of the intermediate protecting portion, the thickness of the outer edge of the edge overlap portion on a side away from the intermediate protecting portion is less than the thickness of the intermediate protecting portion, and the thickness of the edge overlap portion gradually decreases from the side connected to the intermediate protecting portion to the side away from the intermediate protecting portion.

2. The window protective film according to claim 1, characterized in that: The edge overlap portion circumferentially surrounds the outer side of the middle protection portion.

3. A cover plate, characterized in that: The cover plate includes a window portion and a non-window portion surrounding the window portion in a circumferential direction, a receiving groove is provided on one side surface of the non-window portion, and the receiving groove is located outside the window portion; The receiving groove is used to receive the edge overlap portion of the window protection film according to any one of claims 1 or 2, and the edge overlap portion is partially received in the receiving groove.

4. The cover plate according to claim 3, characterized in that: The receiving groove circumferentially surrounds the viewing window portion.

5. The cover plate according to claim 3, characterized in that: The depth of the accommodating groove gradually increases from a side close to the window portion to a side far away from the window portion.

6. The cover plate according to claim 3, characterized in that: The cover plate is provided with a side surface of the receiving groove covering the pad-printed ink layer surrounding the window portion, the edge overlapping portion overlaps the pad-printed ink layer located in the receiving groove, and the edge of the edge overlapping portion away from the middle protection portion is flush with the side surface of the pad-printed ink layer away from the cover plate.

7. A display device, characterized in that: It comprises a display substrate and a cover plate as claimed in any one of claims 3 to 6, wherein the cover plate covers one side of the display substrate.

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