阅读说明：本技术 偏光片及其制作方法、柔性显示屏和电子设备 (Polaroid and manufacturing method thereof, flexible display screen and electronic equipment ) 是由 吕城龄 陈文红 黄聪 于 2020-05-27 设计创作，主要内容包括：本申请涉及柔性显示装置技术领域,尤其涉及一种偏光片及其制作方法、柔性显示屏和电子设备。该偏光片,包括第一表面,所述第一表面包括第一区域和第二区域,所述第二区域位于所述第一表面的边缘区域；所述第一区域与所述第二区域的表面粗糙度不同,且所述第二区域的表面粗糙度大于所述第一区域的表面粗糙度。本申请能够提高偏光片的表面结合力,降低连接层与偏光层之间脱落失效的风险,同时不影响偏光片的光学显示性能。(The application relates to the technical field of flexible display devices, in particular to a polarizer, a manufacturing method of the polarizer, a flexible display screen and electronic equipment. The polarizer comprises a first surface, a second surface and a third surface, wherein the first surface comprises a first area and a second area, and the second area is positioned in the edge area of the first surface; the first region and the second region have different surface roughness, and the second region has a surface roughness greater than that of the first region. The application can improve the surface bonding force of the polaroid, reduce the risk of falling failure between the connecting layer and the polarizing layer, and simultaneously does not influence the optical display performance of the polaroid.)

1. A polarizer comprising a first surface, wherein the first surface comprises a first region and a second region, wherein the second region is located at an edge region of the first surface;

the first region and the second region have different surface roughness, and the second region has a surface roughness greater than that of the first region.

2. The polarizer according to claim 1, wherein the Ra value of the surface roughness of the second region is not more than 4.5 μm.

3. The polarizer according to claim 2, wherein the Ra value of the surface roughness of the second region is in the range of 0.3 μm to 4.5 μm.

4. The polarizer of claim 1, wherein the second region has a relief structure comprising at least one recess.

5. The polarizer of claim 4 wherein the depth of the recesses is less than the thickness of the polarizer, and the depth of the recesses is not more than 15 μm.

6. The polarizer of claim 5, wherein the depth of the concave portion ranges from 3 μm to 10 μm.

7. The polarizer of claim 4, wherein the cross-sectional shape of the concave portion comprises a triangle, a square, a trapezoid, a prism, a semicircle, an ellipse, a drop, or a combination thereof.

8. The polarizer according to any of claims 1 to 7, wherein said second region is located in an edge region around said first surface;

alternatively, the second regions are located at four corner regions of the first surface.

9. A flexible display screen is characterized by comprising a polaroid, and a connecting layer and an organic layer which are sequentially laminated on the polaroid;

the surface of the polaroid, which is in contact with the connecting layer, is a first surface, the first surface comprises a first area and a second area, and the second area is positioned in the edge area of the first surface;

the first region and the second region have different surface roughness, and the second region has a surface roughness greater than that of the first region.

10. The flexible display screen of claim 9, wherein the bonding force between the second region and the connection layer is greater than the bonding force between the first region and the connection layer.

11. A flexible display screen according to claim 9 wherein the surface roughness of the second region has an Ra value of no more than 4.5 μm.

12. A flexible display screen according to claim 9, wherein the second region has a relief structure comprising at least one recess.

13. A flexible display according to claim 12 wherein the connection layer comprises a first portion filling the at least one recess and a second portion located outside the at least one recess.

14. The flexible display of claim 12, wherein the depth of the recess is less than the thickness of the polarizer, and the depth of the recess is less than the thickness of the connecting layer;

the depth of the recessed portion is not more than 15 μm.

15. The flexible display of claim 12, wherein the cross-sectional shape of the recessed portion comprises a triangle, square, trapezoid, prism, semicircle, oval, drop, or a combination thereof.

16. A flexible display screen according to any of claims 9 to 15 wherein the material of the attachment layer comprises an optical glue.

17. An electronic device, comprising:

a housing assembly, and the flexible display of any one of claims 9-16 attached to the housing assembly.

18. A method for manufacturing a polarizer, wherein the polarizer is the polarizer of any one of claims 1 to 8, the method comprising:

and providing a polarizer, and processing a second area of the polarizer to enable the surface roughness of the second area to be larger than that of the first area.

19. The polarizer manufacturing method according to claim 18, wherein the concavo-convex structure is formed in the second region by rolling.

Technical Field

The application relates to the technical field of flexible display devices, in particular to a polarizer, a manufacturing method of the polarizer, a flexible display screen and electronic equipment.

Background

In recent years, with the development of flexible display technology, the advantages of the flexible display screen, such as being light, thin, portable, not fragile, bendable, wearable, etc., are increasingly highlighted, and the flexible display screen is more and more favored by people and is further more and more applied to various terminal devices.

In order to reduce the reflectivity and transmittance of the Display, the polarizer is widely applied to Display devices such as an organic light-Emitting Diode (OLED) Display and a Liquid Crystal Display (LCD). In a flexible display device, a polarizer is required to meet certain optical requirements, and also has the characteristics of bending resistance, good bonding force between films connected with the polarizer, and the like. For example, in the prior art, a polarizer and a cover plate or other organic film layer are bonded by an Optical Clear Adhesive (OCA) layer. However, the surface of the conventional polarizer is not specially arranged, and the bonding force of the edge and the middle of the polarizer and the interface formed by the OCA optical cement is consistent and weak, so that the interface formed by the polarizer and the OCA optical cement is easily degummed.

Therefore, in the conventional flexible display device, because the surface bonding force of the polarizer is weak in the bending process, the interface formed by the polarizer and the OCA is easy to fall off and lose efficacy, so that the performance of the flexible display device is affected, and the use requirement cannot be completely met.

Disclosure of Invention

An object of the present application is to provide a polarizer, a method for manufacturing the polarizer, a flexible display panel, and an electronic device, which can improve the surface bonding force of the polarizer, do not affect the optical display performance of the polarizer, and can overcome the above problems in the background art or at least partially solve the above technical problems.

According to a first aspect of the present application, there is provided a polarizer, comprising a first surface comprising a first region and a second region, the second region being located at an edge region of the first surface;

the first region and the second region have different surface roughness, and the second region has a surface roughness greater than that of the first region.

In one possible implementation, the Ra value of the surface roughness of the second region is not greater than 4.5 μm.

In one possible implementation, the Ra value of the surface roughness of the second region ranges from 0.3 to 4.5 μm.

In a possible implementation, the second region has a relief structure comprising at least one recess.

In one possible implementation, the depth of the concave portion is less than the thickness of the polarizer, and the depth of the concave portion is not more than 15 μm.

In one possible implementation, the depth of the recess is in the range of 3-10 μm.

In one possible implementation, the cross-sectional shape of the concave portion includes a triangle, a square, a trapezoid, a prism, a semicircle, an ellipse, a drop shape, or a combination thereof.

In a possible implementation, the second region is located in an edge region around the first surface;

alternatively, the second regions are located at four corner regions of the first surface.

According to a second aspect of the present application, there is provided a flexible display panel, including a polarizer, and a connection layer and an organic layer sequentially stacked on the polarizer;

the surface of the polaroid, which is in contact with the connecting layer, is a first surface, the first surface comprises a first area and a second area, and the second area is positioned in the edge area of the first surface;

the first region and the second region have different surface roughness, and the second region has a surface roughness greater than that of the first region.

In a possible implementation manner, a bonding force between the second region and the connection layer is greater than a bonding force between the first region and the connection layer.

In one possible implementation, the Ra value of the surface roughness of the second region is not greater than 4.5 μm.

In a possible implementation, the second region has a relief structure comprising at least one recess.

In one possible implementation, the connection layer includes a first portion filling the at least one recess, and a second portion located outside the at least one recess.

In one possible implementation, the depth of the concave part is less than the thickness of the polarizer, and the depth of the concave part is less than the thickness of the connecting layer;

the depth of the recessed portion is not more than 15 μm.

In one possible implementation, the cross-sectional shape of the concave portion includes a triangle, a square, a trapezoid, a prism, a semicircle, an ellipse, a drop shape, or a combination thereof.

In one possible implementation, the material of the connection layer includes an optical glue.

According to a third aspect of the present application, there is provided an electronic device comprising:

a housing assembly, and a flexible display screen as described above connected to the housing assembly.

According to a fourth aspect of the present application, there is provided a method for manufacturing a polarizer, including:

and providing a polarizer, and processing a second area of the polarizer to enable the surface roughness of the second area to be larger than that of the first area.

In one possible implementation, the concave-convex structure is formed in the second area by rolling.

The technical scheme provided by the application can achieve the following beneficial effects:

the surface structure of the polaroid is improved, the first surface of the polaroid is set to be the first area and the second area, the second area can be located in the edge area of the first surface, the surface roughness of the second area is larger than that of the first area, for example, a certain microstructure concave-convex pattern can be formed in the second area at the edge to increase the surface roughness of the second area, and the surface adhesive force of the second area is improved. Therefore, when the connecting layer is attached to the polaroid, the contact area between the connecting layer and the second region can be increased, the adhesive force of the connecting layer to the surface of the second region is improved, namely, the interface bonding force between the polaroid and the connecting layer can be improved, and therefore the falling risk of the connecting layer can be reduced or eliminated.

Therefore, the flexible display panel and the electronic device including the polarizer of the present application have at least the same advantages as the polarizer described above, and are not described herein again.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly described below, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an electronic device in the prior art;

fig. 2 is a schematic structural diagram of a flexible display screen in the prior art;

FIG. 3 is a schematic diagram of a flexible display panel according to the prior art;

FIG. 4 is a schematic diagram of a flexible display screen according to an exemplary embodiment of the present application;

FIG. 5 is a schematic diagram of a polarizer structure according to an exemplary embodiment of the present disclosure;

FIG. 6 is a schematic diagram of a polarizer structure according to an exemplary embodiment of the present disclosure;

FIG. 7 is a schematic diagram illustrating the shape structure of a concave-convex structure in a polarizer according to an exemplary embodiment of the present disclosure;

FIG. 8 is a schematic diagram illustrating the shape and structure of concave-convex structures in a polarizer according to another exemplary embodiment of the present application;

FIG. 9 is a schematic diagram illustrating the shape and structure of concave-convex structures in a polarizer according to another exemplary embodiment of the present application;

FIG. 10 is a schematic diagram illustrating the shape and structure of concave-convex structures in a polarizer according to another exemplary embodiment of the present application;

FIG. 11 is a schematic diagram illustrating the shape and structure of concave-convex structures in a polarizer according to another exemplary embodiment of the present application;

FIG. 12 is a graphical illustration of tensile shear strength versus surface roughness provided by an exemplary embodiment of the present application;

FIG. 13 is a simplified model of a rough surface and a Tabor unimodal model schematic provided by an exemplary embodiment of the present application.

Wherein the reference numerals are as follows:

1-a support sheet; 2-a substrate; 3-a display panel; 4-a polarizer; 5-adhesive layer, optical glue layer; a 6-PI layer; 51-peripheral region location;

7-a tie layer; 8-organic layer;

41-a first surface; 401 — a first region; 402-a second region; 421-a concave-convex structure; 4211-concave part.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

Detailed Description

For better understanding of the technical solutions of the present application, the following detailed descriptions of the embodiments of the present application are provided with reference to the accompanying drawings. It should be understood that the embodiments described are only a few embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Unless defined or indicated otherwise, technical and scientific terms used herein have the same meaning as is familiar to those skilled in the art.

[ electronic apparatus ]

In order to facilitate understanding of the polarizer and the flexible display panel including the polarizer provided in the embodiments of the present application, an application scenario of the polarizer and the flexible display panel including the polarizer may be applied to an electronic device, particularly a foldable electronic device (flexible mobile terminal). In particular, the electronic device may be implemented in various forms, including, but not limited to, a foldable cell phone, a tablet, a laptop, a car computer, a foldable display device (e.g., a television), a wearable device, an Augmented Reality (AR) device, a Virtual Reality (VR) device, an audio or video playback device, a Personal Digital Assistant (PDA), and so on. In addition, the electronic device of the present application is not limited to the above-described device, but may include a newly developed electronic device. The embodiment of the present application is not particularly limited to the specific form of the electronic device.

Illustratively, as shown in fig. 1, the electronic device may be a folding electronic device, such as a flexible folding handset, including an inner folding machine, an outer folding machine, a triple folding machine, and the like.

The foldable electronic device may include a flexible display screen and a housing assembly, the flexible display screen may be connected with the housing assembly. The flexible display screen may also be referred to as a folding screen or a folding display screen, and the flexible display screen forms a display surface of the electronic device, is used for displaying information, and does not provide an interactive interface for a user. The housing assembly may be used to house functional components such as a flexible display, a circuit board, a battery, etc.

Further, the folding electronic device may further include a folding mechanism, and the folding and unfolding of the folding electronic device may be achieved by the folding mechanism. The housing assembly may include a first housing portion and a second housing portion, the flexible display screen may be connected to the first housing portion and the second housing portion, and the first housing portion and the second housing portion may be connected by a folding mechanism.

The flexible display screen can include two fixed parts and a flexion, and two fixed parts can respectively with first casing part and second casing part fixed connection, and the flexion can set up with folding mechanism relatively.

In order to provide the user with the required functions, the folding electronic device may further include other components arranged inside the device, which are not described in detail herein since they are not related to the improvements of the present application.

It should be understood that the illustrated structure of the embodiments of the present application does not constitute a specific limitation to the electronic device. The present application is not particularly limited to the structure and connection of the housing assembly, the folding mechanism, the components disposed inside the device, and the like, and therefore, will not be described in detail herein.

The flexible display in the electronic device will be further explained below.

[ Flexible display Panel ]

The flexible display screen can also be called as a folding screen or a folding display screen, and has the advantages of being bendable, light, thin, portable and the like. The folding screen is small in size after being bent, good convenience can be achieved, a large display area can be provided after the folding screen is unfolded, and more display information can be provided. The flexible display screen can be folded inwards, outwards, three-folded and the like.

As shown in fig. 2, an existing flexible display Panel includes a display Panel 3(Panel), a protective cover or PI layer 6 (e.g., a Polyimide Film, a PI Film) and a polarizing Polarizer 4(Polarizer, POL) may be disposed on one side surface of the Panel, and a Base Film or substrate 2(Base Film) may be disposed on the other side surface of the Panel, so as to protect the Panel. In addition, when the lower side of Panel is used to solve flatness, a whole metal sheet (e.g., SUS, stainless steel) is usually placed as the support sheet 1. An adhesive layer 5 or bonding layer is typically provided between the layers of the flexible display so that the layers are integral. For example, in the flexible display screen, the POL layer (polarizer 4) and the PI layer 6 are bonded together through the adhesive layer 5 (for example, OCA optical adhesive layer), however, the problem of Peeling failure easily occurs between the PI layer and the POL layer in the bending process of the flexible display screen at present. In particular:

in some prior arts, as shown in fig. 3, the flexible display screen may include a PI layer 6, an OCA optical adhesive layer 5, and a polarizer 4(POL layer) stacked in sequence, wherein the size of the PI layer 6 may be larger than that of the polarizer 4, that is, the cross-sectional area of the PI layer 6 may be larger than that of the polarizer 4, and the cross-sectional area of the OCA optical adhesive layer 5 may be adapted to the cross-sectional area of the polarizer 4, and the polarizer 4 is bonded to the PI layer 6 through the OCA optical adhesive layer 5. Thus, the interface bonding force between the polarizer 4 and the OCA optical adhesive layer 5 is smaller than the bonding force between the PI layer 6 and the OCA optical adhesive layer 5, so that the interface formed by the POL and the OCA is easily degummed, and bubbles begin to appear at the peripheral area 51 of the edge of the module during bending, which then causes further large-area shedding.

It can be seen that, because the surface of the conventional polarizer is not specially arranged, the bonding force of the interface formed by the edge and the middle of the polarizer and the OCA optical adhesive layer is consistent and weak, so that the interface formed by the polarizer and the OCA optical adhesive layer is easy to degum. Therefore, how to improve the surface bonding force of the polarizer, so that the polarizer and the adhesive layer have better interface bonding force, and the phenomenon of degumming or large-area peeling is avoided, becomes a problem to be solved at present.

Based on this, in order to overcome the imperfection of the prior art, the technical scheme of the embodiment of the application provides a polarizer and a flexible display screen comprising the polarizer, and the problem that the optical adhesive material and the polarizer are easy to fall off and lose efficacy in the bending process of the flexible display screen is solved by improving the surface structure of the polarizer.

Those skilled in the art will appreciate that the foregoing describes the polarizer in detail by taking the example of the adhesion of the OCA optical adhesive to the polarizer, however, it should be understood that similar adhesive materials or other film materials may have the same or similar problems with the attachment of the polarizer. That is, for convenience of description, the flexible display panel is specifically described in the embodiments of the present application by taking the adhesion of the OCA optical adhesive and the polarizer as an example. However, the principles of the present invention may be implemented in any suitably arranged flexible display panel and are not limited to the bonding between the OCA optical glue and the polarizer. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

Specifically, in some embodiments, as shown in fig. 4 and 5, the present application provides a flexible display screen comprising:

the polarizer 4 and the connection layer 7 and the organic layer 8 which are sequentially laminated on the polarizer 4, that is, the polarizer 4 and the organic layer 8 can be connected together through the connection layer 7;

the polarizer 4 and the connecting layer 7 are attached to each other, the surface of the polarizer 4 in contact with the connecting layer 7 may be a first surface 41, the first surface 41 includes a first region 401 and a second region 402, and the second region 402 is located at the edge region of the first surface 41;

the surface roughness of the first region 401 is different from that of the second region 402, and the surface roughness of the second region 402 is greater than that of the first region 401.

In the embodiment of the invention, the surface structure of the polarizer is improved, and the surface of the polarizer, which is in contact with the connecting layer, is set to be the first area and the second area, wherein the second area can be positioned at the edge area of the first surface, and the surface roughness of the second area is larger than that of the first area, for example, a certain microstructure concave-convex pattern can be formed in the second area at the edge to increase the surface roughness of the second area, so that the contact area of the connecting layer and the second area can be increased, the adhesive force of the connecting layer to the surface of the second area can be improved, that is, the interface bonding force between the polarizer and the connecting layer can be improved, and therefore, the falling risk of the connecting layer can be reduced or eliminated. In addition, the first surface area of the polarizer is divided into a first area and a second area, the second area is subjected to rough treatment, and the first area does not need to be treated, namely the structure of the first area can be the same as or similar to the surface structure of the existing polarizer, so that the normal optical performance of the polarizer cannot be influenced. Therefore, on the premise of ensuring the optical display performance of the normal polaroid, the polaroid also improves the adhesive force between the polaroid and the connecting layer, and effectively relieves the problem of interface separation or falling off of the polaroid and the connecting layer.

It should be noted that the structure of the flexible display screen has various forms.

In some embodiments, the flexible display may be an organic light-Emitting Diode (OLED) display or the like.

It will be appreciated that the flexible display may include a plurality of layer structures including, but not limited to, the polarizer, tie layer, and organic layer described above, and may also include other multilayer structures, which are all flexible. It should be noted that the flexible display shown in fig. 4 is only an example, and in other embodiments, the flexible display may be configured in other similar structures as needed.

For example, the flexible display screen may include a flexible substrate layer, an OLED light emitting layer, a polarizer, a connection layer, and an organic layer (a cover plate, a protective film layer, etc.) sequentially stacked.

For another example, the flexible display panel may include a flexible support layer, a flexible display panel, a polarizer, a connection layer, an organic layer, a connection layer, and a protective film, which are sequentially stacked.

For another example, the flexible display screen may include a support member, a foam, a substrate, a display layer, an isolation layer, a touch layer, a polarizer, a connection layer, and an organic layer, which are stacked in a sub-stack.

For another example, the flexible display screen may include a substrate, a thin film transistor layer, an organic light emitting diode layer, a thin film encapsulation layer, a touch layer, a polarizer, a connection layer, and an organic layer, which are sequentially stacked.

It should be noted that the layer structure of the flexible display screen is not limited to the above listed several structure forms, and the flexible display screen may also adopt other layer structure forms under the condition of meeting the requirement of the folding display, and the application is not particularly limited to this.

In some embodiments, the organic layer 8 may be a cover plate, and the material of the organic layer may be a transparent organic material having flexibility or bendability, including but not limited to Polyimide (PI).

In some embodiments, the organic layer 8 may include a cover plate and a protective film layer, wherein one surface of the cover plate may be bonded to the polarizer through a connection layer, and the other surface of the cover plate may be bonded to the protective film layer through another connection layer. The material of the organic layer may be one or more polymer materials that are flexible or bendable. The polymer material may be one or more of organic flexible materials such as acrylate resin, vinyl resin, polyurethane resin, methacrylate resin, polyisoprene, or cellulose resin.

In some embodiments, the material of the organic layer 8 may include one or more combinations of PI, Polyethylene terephthalate (PET), Polycarbonate (PC), Polyacrylate (Polyacrylate), Polyetherimide (PEI), Polyethersulfone (PES), Polymethylmethacrylate (PMMA), and the like. In the embodiments of the present application, the specific type of the material of the organic layer is not limited.

Use the material on organic layer as the PI example, through the setting on this PI layer, can prevent that flexible display screen from by external effort scraping, can reach the protection on PI layer promptly and be difficult to cracked, even take place cracked, under the protection on PI layer, the glass piece can not the fish tail user yet, in addition, also can prevent that water, oxygen etc. from getting into flexible display screen inside and causing the destruction to flexible display screen.

The flexible display panel may include the organic layer as a cover plate, or may include the cover plate made of PI material and a protective film layer, and the cover plate made of PI material and the protective film layer may be connected by a connection layer (adhesive layer). The protective film layer may include an inorganic material film layer, an inorganic-organic material mixed film layer, an inorganic material film layer-organic material film layer-inorganic material film layer stack-inorganic material film layer-organic material film layer-inorganic-organic material mixed film layer stack, and the like.

In some embodiments, the connection layer 7 may be an adhesive layer or a sticky layer, and the material of the connection layer 7 includes an optical glue. It is to be understood that the connecting layer 7 may be a layered structure formed by optical adhesive bonding between the polarizer and the organic layer and then curing. The optical Adhesive may be, for example, Optically Clear Adhesive (OCA), Optically Clear Resin (OCR), or the like.

The optical adhesive is a transparent adhesive which can be used for bonding optical elements in electronic equipment, has the characteristics of high transparency, high light transmission, water resistance, high temperature resistance and the like, has controlled thickness, can provide uniform spacing, and is an important part for bonding in display screens and the like of the electronic equipment. The material of the optical cement may be of various types including, but not limited to, silicone, acrylic, unsaturated polyester, epoxy, polyurethane, and the like. In the embodiments of the present application, the specific material type of the optical cement is not limited.

It should be noted that, in general, the materials of the current polarizer have no viscosity, and the polarizer is connected with other film structures in the flexible display panel by forming an adhesive layer (connection layer) on at least one side surface of the polarizer.

In some embodiments, the material of the polarizer 4 may include polyvinyl alcohol (PVA), Carbon Nanotube (CNT), or the like. The specific material of the polarizer may be selected and set according to actual requirements, which is not limited in the embodiments of the present application.

In order to improve the connection reliability between the polarizer and other film layers in the flexible display screen, the polarizer is divided into a first area and a second area, and when the polarizer and the connection layer are attached to each other, in some embodiments, the bonding force between the second area and the connection layer is greater than the bonding force between the first area and the connection layer.

In the flexible display screen, the polarizer comprises a first surface which is in contact with the connecting layer, the first surface comprises a first area and a second area, the second area can be located at the edge area of the first surface, and the surface roughness of the second area is larger than that of the first area. That is, the second region may be roughened, for example, the second region may be formed with some rugged patterns, and the first region may not need to be processed, that is, the first region may be the surface of different existing polarizers. Thus, the surface of the first region in contact with the connection layer may be a smooth surface, and the surface of the second region in contact with the connection layer may be uneven. Therefore, the concave-convex pattern with the certain microstructure is arranged in the edge region of the first surface, namely the second region, the contact area of the connecting layer and the second region is larger, and the binding force of the connecting layer such as an OCA optical adhesive layer and the surface of the polaroid is greatly improved under the physical actions of pressure and the like, so that the binding force between the second region and the connecting layer is larger than the binding force between the first region and the connecting layer.

In addition, because the connecting layer is easier to fall off at the edge position of the polaroid than at the central position, a certain microstructure concave-convex pattern can be arranged only in the edge area, namely the second area, of the polaroid, so that the problem of falling off and failure of the optical adhesive material and the polaroid can be effectively solved, and meanwhile, the normal optical display performance of the polaroid can be ensured.

In some embodiments, as shown in fig. 4-6, the second region 402 has a relief structure 421, the relief structure 421 including at least one depression 4211. The thickness of the connection layer 7 may be greater than the depth of the depression 4211, and a part of the structure of the connection layer 7 is embedded in the depression 4211. From this, through this kind of structural setting, can be so that link together more can be stably between articulamentum and the polaroid to can improve flexible display screen's overall structure intensity, avoid the articulamentum to drop and influence whole flexible display screen's performance from the polaroid.

In some embodiments, the connection layer 7 includes a first portion filling the at least one indentation 4211, and a second portion located outside the at least one indentation 4211. The connection layer, such as OCA optical cement, may be physically pressed into the recess of the second region, the portion entering the recess may be a first portion of the connection layer, and the remaining portion of the connection layer, i.e., the second portion, may be located outside the recess. Like this, get into the concave part with OCA optical cement through physics extrusion, it is fixed through the pressurize shaping, will hardly break loose in following the polaroid to can improve the adhesion by a wide margin.

It should be noted that, in other embodiments, in the flexible display panel, a first region and a second region may be disposed on at least one surface of the polarizer, that is, the polarizer may include a first surface and a second surface, where the first surface and the second surface face away from each other, and both the first surface and the second surface may include the first region and the second region, and the second region is located at an edge region of the first surface and the second surface, respectively; the first region and the second region have different surface roughness, and the second region has a surface roughness greater than the surface roughness of the first region. The first surface may be used to attach to the tie layer, i.e., the adhesive layer, and the second surface may also be used to attach to the tie layer, i.e., the adhesive layer. The embodiments of the present application mainly use the specific structure of the first surface of the polarizer as an example for detailed description, however, the surface structure arrangement and principle are also applicable to the second surface, and will not be described in detail herein.

As can be seen from the above description, in the embodiments of the present invention, by improving the surface structure of the polarizer, at least one surface of the polarizer is divided into a first area and a second area, the first area may adopt a normal or ordinary surface structure of the polarizer without processing, and the second area may form some rugged patterns by some forming methods, such as a roller. Therefore, when the polarizer and the connecting layer such as an OCA optical adhesive layer are mutually attached, the bonding force or the binding force of the polarizer and the OCA optical adhesive is greatly improved due to the physical micro concave-convex patterns, so that the problem of interface falling failure of the polarizer and the OCA optical adhesive is effectively solved.

[ polarizing plate ]

In some embodiments, the polarizer in the flexible display panel will be described in detail with reference to the specific embodiments and the accompanying drawings.

Specifically, in some embodiments, as shown in fig. 5 to 11, the present application provides a polarizer 4, including a first surface 41, where the first surface 41 includes a first region 401 and a second region 402, and the second region 402 is located at an edge region of the first surface 41;

the surface roughness of the first region 401 is different from that of the second region 402, and the surface roughness of the second region 402 is greater than that of the first region 401.

For the advantages of the polarizer over the prior art, reference may be made to the description of the flexible display portion above, which is not described herein again.

It should be noted that the first region may be a normal polarizer surface, that is, the first region may not need to be processed, and thus, specific values of the surface roughness of the first region are not particularly limited as long as the surface roughness Ra value of the first region is smaller than that of the second region.

In order to facilitate understanding to increase the surface roughness of the second region, the adhesive force or the bonding force between the connecting layer and the second region can be greatly improved, and then the adhesive force or the bonding force between the connecting layer and the polarizer can be greatly improved, so that the falling risk between the connecting layer and the polarizer is reduced. Fig. 12 is a graph showing the relationship between the surface roughness and the shear strength (tensile shear strength, tensile shear strength for short). Referring to fig. 12, when the surface roughness is in the second region, the tensile shear strength can be greatly improved. In this region, the interfacial tensile shear strength can be explained by using a rough surface simplified model shown in fig. 13(a) and a Tabor unimodal model shown in fig. 13 (b). As can be seen from fig. 13(a) and 13(b), the plane with less roughness can be regarded as a profile shown by a dotted line in fig. 13(a), that is, a profile without roughening treatment (or a profile after grinding), and the inclination angle thereof is small. While the roughness decreases, the angle of inclination of the peak decreases. The Tabor unimodal model formula is as follows:

wherein, mu_dTo an equivalent coefficient of friction, mu₀As the initial interface constant, θ is the rubbing angle.

According to the Tabor unimodal model formula, the equivalent friction coefficient mu of the interface can be known_dAnd initial interface constant mu₀Relative to the friction angle θ; constant μ at the initial interface₀At a certain time, the equivalent friction coefficient mu of the interface_dIncreases as theta increases. Therefore, the greater the surface roughness, the greater the equivalent coefficient of friction, and the greater the interfacial shear strength. However, as shown in fig. 12, the friction coefficient cannot be infinitely large, and the excessive strength is rather lowered.

Based thereon, taking into account the relationship of surface roughness and tensile shear strength, in some embodiments, the Ra value of the surface roughness of the second region is not greater than 4.5 μm. As can be seen from fig. 12, the Ra value of the surface roughness tends to decrease after increasing to a certain extent, and therefore, the Ra value of the surface roughness is preferably not larger than the maximum value (the highest point on the curve). That is, the Ra value of the surface roughness is not more than 4.5 μm (less than or equal to 4.5 μm), the tensile-shear strength can be ensured, and the adhesive force of the connecting layer and the polarizer can be effectively improved.

Further, the Ra value of the surface roughness of the second region may range from 0.3 to 4.5 μm (micrometers). As shown in fig. 12, in the first region, the tensile strength decreases as the surface roughness increases, in the second region, the tensile strength increases greatly as the surface roughness increases, and in the third region, the tensile strength decreases as the surface roughness increases. Therefore, the surface roughness in the second area range can greatly improve the shearing strength of the interface, and is more favorable for improving the adhesive force or the bonding force of the connecting layer and the polaroid, improving the connection stability of the connecting layer and the polaroid and the overall strength of the structure, and reducing the risk of falling failure between the connecting layer and the polaroid. Therefore, the Ra value of the surface roughness of the second region in the embodiment of the present invention is defined as 0.3 to 4.5. mu.m, further 0.5 to 4.5. mu.m, further 2.5 to 4.4. mu.m, further 3.5 to 4.2. mu.m, and the like.

Illustratively, the Ra value of the surface roughness of the second region may be any value from among 0.3 μm, 0.5 μm, 0.8 μm, 1.0 μm, 1.2 μm, 1.5 μm, 1.8 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.2 μm, 4.5 μm, and a range of any two of these points.

In some embodiments, regarding the relative sizes of the first region and the second region, for example, the area ratio of the first region to the second region may be 3-50:1, may be 5-40:1, may be 6-40:1, may be 8-38:1, may be 10-35:1, and so forth. The relative proportion value of the first area and the second area or the proportion value of the second area in the whole first surface can be selected and set according to actual requirements, and the embodiment of the application does not limit the relative proportion value.

In some embodiments, the second region 402 has a relief structure 421, the relief structure 421 may also be referred to as a relief strip microstructure or a relief pattern, and the relief structure 421 includes at least one depression 4211.

It should be noted that the concave-convex structure is a micro-structure concave-convex pattern arranged according to needs, and is different from a conventional manufacturing method, and an uneven state cannot be avoided. The concavo-convex structure may include a concave structure with respect to a reference plane of the polarizer (a surface of the polarizer at a flat place), may also include a convex structure that is convex with respect to the reference plane, or may also include a combined pattern of the concave structure and the convex structure. Since the concave state and the convex state are opposite, for convenience of description, the embodiments of the present application collectively refer to the concave structure and the convex structure as a concave portion, or may also be referred to as a groove.

In order to further secure the surface adhesion or bonding force of the second region, the depth of the concave portion of the second region may be made within a suitable range. In some embodiments, the depth of the concave portion is less than the thickness of the polarizer, and the depth of the concave portion is also less than the thickness of the polarizer, so that the mechanical strength of the polarizer can be enhanced; specifically, the depth of the recessed portion may be not more than 15 μm (≦ 15 μm). For example, as shown in FIG. 6, the depth of the recesses may be denoted as H1, i.e., the average dimension of the recesses perpendicular to the polarizer may be understood as H1; the thickness of the polarizer may be denoted as H2.

For the polarizer, the depth H1 of the concave portion may be 0.1 to 0.8 times, further may be 0.2 to 0.6 times, further may be 0.25 to 0.5 times, further may be 0.3 to 0.4 times the thickness H2 of the polarizer.

It should be noted that, the specific thickness values of the polarizer and the tie layer in the embodiments of the present application are not limited, and those skilled in the art can select and set the thickness values according to actual needs, and will not be described in detail herein.

In some embodiments, the depth of the concave portion may be selectively set according to the material of the polarizer and the thickness of the polarizer, for example, the depth of the concave portion may be in a range of 3-10 μm, further 3-9 μm, further 4-8 μm, further 5-6 μm, and the like. Illustratively, the depth of the recessed portion may be any value in a range of 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 10 μm, and any two of these point values. In the depth range of the concave part, the optical glue is more favorable to entering the concave part through physical extrusion and other modes, and is fixed through pressure maintaining molding, so that the optical glue is difficult to break away from the inside of the polarizer, and the surface bonding force or the bonding force of the polarizer can be greatly improved.

It should be noted that the concave-convex structure of the second region includes a plurality of concave portions, for example, the number of the concave portions may be 3-50, or 3-100 or more, and the like.

The concavo-convex structure includes a plurality of concave portions, and the plurality of concave portions may be continuously arranged or may be arranged at intervals. The shapes of the plurality of concave portions may all be the same, or the shapes of the plurality of concave portions may also be different, i.e., the plurality of concave portions may include one or two or more different shapes.

The shape of the concave portion may be various types, and the following exemplary lists several shapes of the concave portion, however, it should be understood that the shape of the concave portion is not limited to these listed shapes, and the shape of the concave portion may also take any other structural form in the case of satisfying the molding process or satisfying the adhesive force requirement.

In addition, in the case of satisfying the molding process or satisfying the requirement of the adhesive force, the distance between the adjacent concave portions or the width of the concave portion may also be set according to the size of the polarizer or other requirements, which is not particularly limited.

Specifically, in some embodiments, the cross-sectional shape of the recessed portion comprises a triangle, a square, a trapezoid, a prism, a semicircle, an ellipse, a drop, or a combination thereof. That is, the cross-sectional shape of the concave portion in the direction perpendicular to the polarizer (or the display panel) may be a triangle (V-shape), a square (e.g., a rectangle or a square), a trapezoid (e.g., a regular trapezoid or an inverted trapezoid), a prism, a semicircle, an ellipse, a drop, a funnel, a grid, a combination of any two or more of the above shapes, a regular or irregular shape, or the like.

It should be noted that the above-mentioned drop shape is understood to be a shape structure formed by a combination of straight and arc structures.

Illustratively, as shown in FIG. 7, in some embodiments, the cross-sectional shape of the recess is preferably drop-shaped. Like this, in optical cement enters into water droplet shape structure through the physics extrusion, fixed through the pressurize shaping, will make optical cement hardly shake off from in the polaroid, increase substantially the adhesion.

Illustratively, as shown in FIG. 8, in other embodiments, the cross-sectional shape of the recess may be triangular.

Illustratively, as shown in FIG. 9, in other embodiments, the cross-sectional shape of the recessed portion may be trapezoidal.

Illustratively, as shown in FIG. 10, in other embodiments, the cross-sectional shape of the recess may be square.

Illustratively, as shown in FIG. 11, in other embodiments, the cross-sectional shape of the recessed portion may be semi-circular.

In addition, it should be noted that the cross-sectional shape of the concave portion in the direction parallel to the polarizer (or the display panel) may also be various, for example, it may be a triangle, a circle, an ellipse, a net, a strip, a broken line, or other regular or irregular shapes, and the like, and this is not limited in this application and will not be described in detail again.

According to the embodiment of the application, a certain microstructure pattern is formed in the edge area of the polaroid, and the bonding force between optical cement such as OCA (optically clear adhesive) and the surface of the polaroid is greatly improved under the physical action of pressure and the like, so that the phenomenon that the OCA optical cement begins to lose efficacy from the edge is improved. Specifically, in some embodiments, as shown in fig. 5, the second region may be located in an edge region around the first surface.

In other embodiments, the second area may be located at four corner areas of the first surface.

Based on the same inventive concept, an embodiment of the present invention further provides a method for manufacturing the polarizer, including:

and providing a polarizer, and processing a second area of the polarizer to enable the surface roughness of the second area to be larger than that of the first area.

The method for manufacturing the polaroid is characterized in that the first surface of the polaroid is set into a first area and a second area, namely a middle non-microstructure area and an edge microstructure area. The surface structure state of the traditional polaroid is changed, a certain microstructure concave-convex pattern is formed in the second area, namely the edge area of the polaroid, and the surface bonding force of the optical adhesive and the polaroid is greatly improved under the physical actions of pressure and the like.

In some embodiments, the surface roughness of the second region has an Ra value in the range of 0.3-4.5 μm.

In some embodiments, the second region has a relief structure comprising at least one recess.

In some embodiments, the depth of the recess is in the range of 3-10 μm.

In some embodiments, the cross-sectional shape of the recess comprises a triangle, a square, a trapezoid, a prism, a semicircle, an ellipse, a drop shape, or a combination thereof, preferably a drop shape (or a funnel shape). Through pressure maintaining molding fixation, the optical adhesive is difficult to break loose from the polarizer, and the bonding force is greatly improved.

It should be noted that there are many techniques for increasing the surface friction, that is, there are many ways for forming a certain microstructure concave-convex pattern in the second region, and for example, various machining ways can be adopted.

For example, in some embodiments, the concave-convex structure may be formed in the second region by rolling. In practical application, a knurling tool in mechanical processing can be adopted for carrying out roll forming. For example, some rugged patterns can be formed in the second area by using a roller, for a high polymer material, due to the resilience after knurling, the depth of the concave part can be set to be 3-10 μm along with the change of the material and the thickness. Then, apply the deaeration process of pressurize after laminating optical cement and polarizer again, optical cement gets into in the concave part through the physics extrusion, and through the shaping of pressurize fixed, will be difficult to break loose from the polarizer in, increase substantially bonding force.

It should be noted that, as used in the examples of the present application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The use of "first," "second," and similar terms in the present application do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

In the description of the present application, it is to be understood that the terms "depth", "width", "thickness", "upper", "lower", "left", "right", "vertical", "horizontal", and the like indicate orientations or positional relationships, and are used merely to indicate relative positional relationships, and when the absolute position of a described object is changed, the relative positional relationships may also be changed accordingly. It will also be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "under" another element, it can be directly connected to the other element not only "on" or "under" the other element but also indirectly connected to the other element through intervening elements.

It is noted that a portion of this patent application contains material which is subject to copyright protection. The copyright owner reserves the copyright rights whatsoever, except for making copies of the patent files or recorded patent document contents of the patent office.