Cover plate structure, preparation method thereof and OLED display module

Abstract

This invention discloses a cover plate structure and its fabrication method, as well as an OLED display module. In one specific embodiment, the cover plate structure includes a transparent layer, a 1 / 4λ phase retardation film, a polarizing layer, and a cover plate stacked together, with a light-shielding portion formed at the edge of the transparent layer. This embodiment can significantly reduce the overall thickness of the OLED display module and provides a method for setting the light-shielding portion.

Description

Technical Field

[0001] This invention relates to the field of display technology. More specifically, it relates to a cover plate structure and its fabrication method, and an OLED display module. Background Technology

[0002] Currently, OLED (Organic Light-Emitting Diode) display modules typically employ a structure where the cover plate and polarizer are independently configured. This results in an overall module thickness that is relatively large. This is particularly true for flexible OLED display modules, where the flexible cover plate and polarizer function as two separate functional structures, leading to a significantly thicker overall module (the total thickness of the two stacked structures exceeds 300μm). This severely limits the bending performance of the flexible OLED display module. Furthermore, the fabrication process for flexible OLED display modules requires the addition of a process to bond the flexible, hardened cover plate to the polarizer, further complicating the manufacturing process and resulting in lower stability and yield rates. Summary of the Invention

[0003] The purpose of this invention is to provide a cover plate structure and its preparation method, as well as an OLED display module, to solve at least one of the problems existing in the prior art.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] The first aspect of the present invention provides a cover plate structure for an OLED display panel, the cover plate structure comprising a transparent layer, a 1 / 4λ phase retardation film, a polarizing layer and a cover plate stacked together, wherein a light-shielding portion is formed at the edge of the transparent layer.

[0006] Optionally, the light-shielding part is an ink light-shielding part.

[0007] Optionally, the transparent layer is an organic polymer material transparent layer.

[0008] Optionally, the transparent layer of the organic polymer material is an acrylic-based transparent layer.

[0009] Optionally, the cover plate structure further includes a 1 / 2λ phase retardation film disposed between the 1 / 4λ phase retardation film and the polarizing layer.

[0010] Optionally, the 1 / 4λ phase retardation film and the 1 / 2λ phase retardation film are liquid crystal phase retardation films.

[0011] Optionally, the 1 / 4λ phase retardation film and the 1 / 2λ phase retardation film, the 1 / 2λ phase retardation film and the polarizing layer, and the polarizing layer and the cover plate are respectively bonded and fixed by adhesive layers.

[0012] Optionally, the cover plate structure further includes an ultrathin glass disposed on the side of the transparent layer opposite to the 1 / 4λ phase reversal film.

[0013] Optionally, the polarizing layer is a polyvinyl alcohol polarizing layer.

[0014] Optionally, the cover plate is a flexible cover plate.

[0015] A second aspect of the present invention provides an OLED display module, including an OLED display panel and a cover plate structure as provided in the first aspect of the present invention disposed on the light-emitting side of the OLED display panel.

[0016] Optionally, the cover plate structure is bonded to the light-emitting side of the OLED display panel using pressure-sensitive adhesive.

[0017] A third aspect of the present invention provides a method for fabricating a cover plate structure for an OLED display panel, comprising:

[0018] A polarizing layer is formed on one side of the cover plate, and a 1 / 4λ phase retardation film is formed on the side of the polarizing layer opposite to the cover plate.

[0019] A light-blocking section is formed at the edge of the transparent layer;

[0020] A transparent layer with a light-shielding portion is fixed to the side of the 1 / 4λ phase retardation film opposite to the polarizing layer.

[0021] Optionally, forming a light-shielding portion at the edge of the transparent layer includes:

[0022] An ink-shielding portion is formed at the edge of the transparent layer using screen printing or spraying processes.

[0023] Optionally,

[0024] The formation of a light-shielding portion at the edge of the transparent layer includes:

[0025] A light-shielding portion is formed at the edge of the first side of the transparent layer, wherein a release film and a carrier film are sequentially disposed on the second side of the transparent layer;

[0026] The step of fixing the transparent layer with the light-shielding portion to the side of the 1 / 4λ phase retardation film opposite to the polarizing layer includes:

[0027] The first side of the transparent layer with the light-shielding portion is bonded and fixed to the side of the 1 / 4λ phase difference film opposite to the polarizing layer by an adhesive layer, and the release film along with the carrier film is peeled off from the second side of the transparent layer.

[0028] A fourth aspect of the present invention provides a method for fabricating a cover plate structure for an OLED display panel, comprising:

[0029] A polarizing layer is formed on one side of the cover plate, and a 1 / 4λ phase retardation film is formed on the side of the polarizing layer opposite to the cover plate.

[0030] A transparent layer is formed on the side of the 1 / 4λ phase retardation film opposite to the polarizing layer, and a light-shielding portion is formed at the edge of the transparent layer.

[0031] Optionally, forming a light-shielding portion at the edge of the transparent layer includes:

[0032] An ink-shielding portion is formed at the edge of the transparent layer using screen printing or spraying processes.

[0033] Optionally, the curing process for the ink-shielding portion in the screen printing or spraying process is a photocuring process.

[0034] The beneficial effects of this invention are as follows:

[0035] The technical solution described in this invention, through the integrated design of the cover plate and the polarizing functional film layer, can significantly reduce the overall thickness of the OLED display module and provides a way to set the edge light-shielding part of the OLED display module. Attached Figure Description

[0036] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0037] Figure 1 This diagram illustrates a structure of a flexible OLED display module according to an embodiment of the present invention.

[0038] Figure 2 Another structural diagram of a flexible OLED display module provided in one embodiment of the present invention is shown.

[0039] Figure 3 A flowchart illustrating a method for fabricating a cover plate structure for a flexible OLED display panel according to another embodiment of the present invention is shown.

[0040] Figure 4 A schematic diagram of the transfer printing process is shown.

[0041] Figure 5 A flowchart illustrating a method for fabricating a cover plate structure for a flexible OLED display panel according to another embodiment of the present invention is shown. Detailed Implementation

[0042] In this invention, "on," "formed on," and "set on" can mean that one layer is directly formed or set on another layer, or that one layer is indirectly formed or set on another layer, meaning that there are other layers between the two layers.

[0043] It should be noted that although the terms "first," "second," etc., may be used herein to describe various components, members, elements, regions, layers, and / or portions, these components, members, elements, regions, layers, and / or portions should not be limited by these terms. Rather, these terms are used to distinguish one component, member, element, region, layer, and / or portion from another. Thus, for example, the first component, first member, first element, first region, first layer, and / or first portion discussed below may be referred to as a second component, second member, second element, second region, second layer, and / or second portion without departing from the teachings of the invention.

[0044] In this invention, unless otherwise stated, the term "co-layer arrangement" refers to two layers, components, members, elements, or portions that can be formed by the same fabrication process (e.g., patterning process), and that these two layers, components, members, elements, or portions are generally formed of the same material. For example, co-layer arrangement of two or more functional layers means that these co-layered functional layers can be formed using the same material layer and the same fabrication process, thereby simplifying the fabrication process of the display substrate.

[0045] In this invention, unless otherwise stated, the term "patterning process" generally includes steps such as photoresist coating, exposure, development, etching, and photoresist stripping. The term "one-step patterning process" refers to a process of forming patterned layers, components, or parts using a single photomask.

[0046] OLED display modules are self-emissive and theoretically do not require two linear polarizers to control the light direction, unlike LCD (Liquid Crystal Display) modules. However, because the cathode of an OLED display module (e.g., a Mg-Ag magnesium-silver alloy with a Mg:Ag ratio between 3:7 and 1:9) has strong reflectivity, the contrast of the OLED display module decreases under strong ambient light, affecting its usability.

[0047] Therefore, current OLED display module manufacturing processes mostly use a circular polarizer to eliminate reflected light. The specific principle is as follows: a circular polarizer consists of a linear polarizer and a 1 / 4λ waveplate. Ambient light (natural light) passes through a linear polarizer (with its absorption axis perpendicular to the horizontal direction), leaving only half horizontally polarized light. This horizontally polarized light then passes through a 1 / 4λ waveplate and becomes left-handed circularly polarized light. After reflection from the OLED display panel, this left-handed circularly polarized light rotates 180° to become right-handed circularly polarized light. This right-handed circularly polarized light then passes through a 1 / 4λ waveplate again and becomes vertically polarized light. Vertically polarized light cannot pass through the linear polarizer (it is absorbed by the linear polarizer with its absorption axis perpendicular to the horizontal direction). Thus, the circular polarizer eliminates the reflection of ambient light from the OLED display panel, ensuring the contrast of the OLED display panel itself. Even under strong sunlight, users can clearly see the screen content. The current method of setting up circular polarizers involves attaching the circular polarizer to the light-emitting side of the OLED display panel, and then attaching the cover plate of the OLED display module to the circular polarizer. In this design, an edge-shielding portion, such as ink, is formed between the circular polarizer and the cover plate to prevent light leakage. This independent arrangement of the cover plate and polarizer results in a relatively thick overall module structure, particularly for flexible OLED display modules where thinness is a critical requirement.

[0048] In view of this, such as Figure 1 and Figure 2 As shown, one embodiment of the present invention provides a flexible OLED display module, including a flexible OLED display panel 200 and a cover plate structure 100 disposed on the light-emitting side of the OLED display panel.

[0049] The cover plate structure 100 includes a stacked arrangement (i.e.) Figure 1 The structure, from bottom to top, comprises a transparent layer 101, a 1 / 4λ phase retardation film 102, a polarizing layer 103, and a flexible cover plate 104. A light-shielding portion 106 is formed at the edge of the transparent layer 101, wherein the light-shielding portion 106 can be configured as follows: Figure 1 As shown, it is formed on the surface of the transparent layer 101 facing the 1 / 4λ phase reversal film 102, or it can be formed as follows: Figure 2 The phase contrast film 102 is formed on one side of the transparent layer 101, opposite to the 1 / 4λ phase contrast film 102.

[0050] In a specific example, the flexible OLED display module can be a foldable OLED display module, and the cover plate 104 can be a flexible cover plate of transparent polyimide (CPI). The flexible cover plate 104 can also be an ultra-thin glass (UTG) cover plate. The material of the flexible cover plate 104 can be polyethylene terephthalate (PET), polypropylene (PP), polyethylene naphthalate (PEN), thermoplastic polyurethane (TPU), polymethyl methacrylate (PMMA), cyclic olefin polymer (COP), polycarbonate (PC), cellulose triacetate (TAC), or transparent polyaramid, etc.

[0051] In a specific example, polarizing layer 103 is a polyvinyl alcohol (PVA) polarizing layer, meaning the material of polarizing layer 103 is polyvinyl alcohol (PVA). Exemplarily, polarizing layer 103 can be an iodine-based polarizing layer, which is obtained by dyeing with iodine dye and possesses polarizing properties based on the optical dichroism of crystals. Specifically, the material of polarizing layer 103 can include PVA (polyvinyl alcohol). A PVA film is immersed in an iodine ion solution to allow iodine ions to diffuse into the PVA film. After slight heating and stretching, the PVA film becomes longer and thinner. The PVA molecules, which are originally randomly distributed at arbitrary angles, gradually and uniformly deflect in the direction of the force after stretching. The dichroic iodine molecules attached to the PVA also become directional, thus forming polarizing layer 103. Polarizing layer 103 has an absorption axis and the function of converting natural light into linearly polarized light (e.g., absorbing vertically polarized light and allowing horizontally polarized light to pass through, thereby converting natural light into linearly polarized light).

[0052] In a specific example, after ambient light passes through a polarizing layer 103 with its absorption axis perpendicular to the direction of polarization, only half of the light is horizontally polarized. This horizontally polarized light then passes through a 1 / 4λ phase retardation film 102 and becomes left-handed circularly polarized light. After being reflected by the flexible OLED display panel 200, the left-handed circularly polarized light rotates 180° and becomes right-handed circularly polarized light. This right-handed circularly polarized light then passes through the 1 / 4λ phase retardation film 102 again and becomes vertically polarized light. Since the vertically polarized light cannot pass through the polarizing layer 103, the polarizing functional film layer composed of the polarizing layer 103 and the 1 / 4λ phase retardation film 102 eliminates the reflection of ambient light by the flexible OLED display panel 200.

[0053] The flexible OLED display module provided in this embodiment significantly reduces the overall thickness of the flexible OLED display module and improves the bending performance of the flexible OLED display module through the integrated design of the flexible cover plate 104 and the polarization functional film layer including at least the polarization layer 103 and the 1 / 4λ phase difference film 102. It also provides a way to set the light-shielding part 105 at the edge of the flexible OLED display module to prevent light leakage.

[0054] In one possible implementation, the light-shielding portion 105 is an ink-based light-shielding portion. That is, the material of the light-shielding portion 105 is ink. For example, the ink-based light-shielding portion can be formed on the transparent layer 101 by processes such as printing (e.g., screen printing) or spraying.

[0055] In one possible implementation, the transparent layer 101 is an organic polymer material transparent layer.

[0056] In one possible implementation, the transparent organic polymer material layer is an acrylic-based transparent material layer. Acrylic, also known as plexiglass, is made of polymethyl methacrylate (PMMA), a high-molecular polymer with advantages such as high transparency, low price, and ease of machining. Alternatively, the transparent organic polymer material layer can also be made of thermoplastic polyurethane (TPU), cellulose triacetate (TAC), or other similar materials.

[0057] In a specific example, the thickness of the transparent layer 101 is 0.5 μm to 20 μm.

[0058] If, in the manufacturing process, the ink-shielding portion is first printed or sprayed onto the transparent layer 101, and then the ink-shielding portion and the transparent layer 101 are integrally transferred onto an integrated structure including a flexible cover plate 104 and a polarizing functional film layer (the polarizing functional film layer includes at least a polarizing layer 103 and a 1 / 4λ phase retardation film 102), then the thickness range of the transparent layer 101 can be selected, for example, from 2μm to 20μm. Further explanation: the product structure formed by this manufacturing process is as follows... Figure 1 or Figure 2 As shown.

[0059] If, in the manufacturing process, the transparent layer 101 is first bonded and fixed to an integrated structure including the flexible cover plate 104 and the polarizing functional film layer, or the transparent layer 101 is formed on the integrated structure including the flexible cover plate 104 and the polarizing functional film layer through a coating process, and then the ink light-blocking portion is printed or sprayed onto the transparent layer 101, then the thickness range of the transparent layer 101 can be selected, for example, from 0.5 μm to 10 μm. Further explanation: the product structure formed by this manufacturing process is as follows... Figure 2 As shown, if the transparent layer 101 is, for example, bonded and fixed to an integrated structure including the flexible cover plate 104 and the polarizing functional film layer, the product structure is as follows: Figure 2 As shown, the transparent layer 101 and the 1 / 4λ phase retardation film 102 are bonded and fixed by an adhesive layer; if the transparent layer 101 is formed on an integrated structure including the flexible cover plate 104 and the polarizing functional film layer by a coating process, then the product structure is similar to... Figure 2 The difference is that there is no adhesive layer between the 1 / 4λ phase difference film 102 and the transparent layer 101.

[0060] It should also be noted that, in addition to forming the light-shielding part 105 (for example, the transparent layer 101 can be used as an ink printing layer), the transparent layer 101 can also protect the 1 / 4λ phase retardation film 102.

[0061] In one possible implementation, such as Figure 1 and Figure 2 As shown, the cover plate structure 100 also includes a 1 / 2λ phase retardation film 106 disposed between the 1 / 4λ phase retardation film 102 and the polarizing layer 103.

[0062] The wavelength range of ambient light (natural light) is very wide, while conventional 1 / 4λ phase retardation films can generally only correspond to a single wavelength. In order to achieve the ideal wide wavelength compensation effect, this implementation method uses a 1 / 2λ phase retardation film 106, for example, stacking it with a 1 / 4λ phase retardation film 102 with a narrow band normal distribution in a certain direction to form a wide band coverage for the visible light band.

[0063] In one possible implementation, the 1 / 4λ phase retardation film 103 and the 1 / 2λ phase retardation film 106 are liquid crystal phase retardation films, or LC polarizing films, respectively. For example, the liquid crystal phase retardation film is composed of an alignment layer and a liquid crystal polymer, wherein the liquid crystal polymer layer is formed by the polymerization and curing of reactive liquid crystals with mutually perpendicular orientations.

[0064] In a specific example, the liquid crystal 1 / 2λ phase retardation film can also be called a 1 / 2λ phase retardation layer or a 1 / 2λ waveplate film layer. The 1 / 2λ waveplate film layer is located on a plane parallel to the flexible OLED display panel 200. Figure 1 Within the horizontal plane of the waveplate, there are fast and slow axes (the direction of the light vector that propagates slowly in the waveplate is the slow axis, and the direction of the light vector that propagates quickly is the fast axis). Natural light passing through the 1 / 2λ waveplate film will produce a phase difference of half a wavelength, which will delay the phase of the natural light by 1 / 2λ. For example, the absorption axis of the polarizing layer 103 forms an acute angle α≈15° with the slow axis of the 1 / 2λ waveplate film.

[0065] Continuing with the previous example, the liquid crystal 1 / 4λ phase retardation film can also be called a 1 / 4λ phase retardation layer or a 1 / 4λ waveplate film layer. The 1 / 4λ waveplate film layer is located on a plane parallel to the flexible OLED display panel 200. Figure 1Within the horizontal plane of the light (the 1 / 4λ waveplate), there are fast and slow axes. The polarization direction can be considered as the directions of two mutually perpendicular components. The 1 / 4λ waveplate has different refractive indices and propagation speeds for light with different polarization directions, resulting in a phase difference between the two components. Therefore, natural light passing through the 1 / 4λ waveplate will have a phase difference of one-quarter wavelength, which will delay the phase of the natural light by 1 / 4λ. For example, the angle between the absorption axis of the polarizing layer 103 and the slow axis of the 1 / 4λ waveplate is 2α+45° (α≈15°, so this angle 2α+45° is approximately 75°).

[0066] In one possible implementation, such as Figure 1 and Figure 2 As shown, the 1 / 4λ phase retardation film 102 and the 1 / 2λ phase retardation film 106, the 1 / 2λ phase retardation film 106 and the polarizing layer 103, and the polarizing layer 103 and the flexible cover plate 104 are respectively bonded and fixed by adhesive layers.

[0067] In a specific example, the three adhesive layers can be ultraviolet-curable adhesive (UV adhesive), pressure-sensitive adhesive (PSA), optically transparent adhesive (OCA), thermosetting water-based adhesive, etc. For example, the three adhesive layers are all optically transparent adhesive (OCA), that is, the 1 / 4λ phase retardation film 102 and the 1 / 2λ phase retardation film 106 are bonded and fixed with optically transparent adhesive (OCA), the 1 / 2λ phase retardation film 106 and the polarizing layer 103 are bonded and fixed with optically transparent adhesive (OCA), and the polarizing layer 103 and the flexible cover plate 104 are bonded and fixed with optically transparent adhesive (OCA).

[0068] In one possible implementation, such as Figure 1 and Figure 2 As shown, the cover plate structure 100 also includes an ultrathin glass 107 disposed on the side of the transparent layer 101 facing away from the 1 / 4λ phase difference film 102, to form a composite cover plate structure.

[0069] In a specific example, the thickness of the ultra-thin glass (UTG) 107 can be 30μm-150μm, such as 30μm, 50μm, 70μm, 90μm, 100μm, 130μm, 150μm, etc. These are not listed exhaustively in this example. Preferably, the thickness of the ultra-thin glass 107 is 50μm-100μm. The width and length of the ultra-thin glass 107 are designed according to actual needs. The ultra-thin glass 107 is formed of inorganic materials. By using inorganic materials, the ultra-thin glass 107 can recover to a relatively flat state even under high temperature and high humidity conditions.

[0070] In one possible implementation, such as Figure 1 and Figure 2 As shown, the cover plate structure 100 is bonded and fixed to the light-emitting side of the flexible OLED display panel 200 using pressure-sensitive adhesive (PSA) or optically transparent adhesive (OCA). Specifically, for example, the ultra-thin glass 107 is bonded and fixed to the light-emitting side of the flexible OLED display panel 200 using PSA. Furthermore, it is understood that if the cover plate structure does not include the bottom layer of ultra-thin glass, the fact that the cover plate structure is bonded and fixed to the light-emitting side of the flexible OLED display panel using PSA means that the transparent layer is bonded to the light-emitting side of the flexible OLED display panel using PSA.

[0071] For example, the flexible OLED display panel 200 includes a back support layer and a display functional layer disposed on the back support layer. For example, the back support layer includes a support member and a back film. For example, the display functional layer includes, for example, a flexible substrate, a buffer layer, a driving circuit layer (or thin film transistor layer, TFT layer), an organic light-emitting functional layer (EL), and an encapsulation layer (TFE) stacked sequentially, with ultra-thin glass 107 bonded to the encapsulation layer (TFE) by pressure-sensitive adhesive. For example, the flexible substrate can be polyimide (PI), polyethylene naphthalate (PEN), thermoplastic polyester (PET), etc.; the organic light-emitting functional layer (EL) includes, for example, an anode, a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), an emissive layer (EML), a hole blocking layer (HBL), an electron transport layer (ETL), an electron injection layer (EIL), and a cathode. For example, the encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer stacked together. The ultra-thin glass 107 is then bonded to the second inorganic encapsulation layer using pressure-sensitive adhesive. For example, the first and second inorganic encapsulation layers are formed by deposition or similar methods. The organic encapsulation layer is formed by inkjet printing. For example, the first and second inorganic encapsulation layers can be formed using inorganic materials such as silicon nitride, silicon oxide, or silicon oxynitride, while the organic encapsulation layer can be formed using organic materials such as polyimide (PI) or epoxy resin. Thus, the first inorganic encapsulation layer, the organic encapsulation layer, and the second inorganic encapsulation layer form a composite encapsulation layer. This composite encapsulation layer provides multiple layers of protection for the functional structure of the display area, resulting in better encapsulation performance.

[0072] like Figure 3 As shown, another embodiment of the present invention provides a method for fabricating a cover plate structure for a flexible OLED display panel, comprising the following steps:

[0073] S301. A polarizing layer is formed on one side of the flexible cover plate, and a 1 / 4λ phase retardation film is formed on the side of the polarizing layer opposite to the flexible cover plate.

[0074] In a specific example, in step S301, a polarizing layer can be first bonded to one side (below) of the flexible cover plate, and then a 1 / 4λ phase retardation film can be bonded to the side (below) of the polarizing layer opposite to the flexible cover plate. Alternatively, a 1 / 4λ phase retardation film can be bonded to one side (below) of the polarizing layer, and a flexible cover plate can be bonded to the other side (above) of the polarizing layer. Step S301 yields an integrated structure including a flexible cover plate and a polarizing functional film layer (the polarizing functional film layer includes a polarizing layer and a 1 / 4λ phase retardation film).

[0075] S302, A light-blocking section is formed at the edge of the transparent layer.

[0076] In one possible implementation, step S302 includes forming an ink-shielding portion at the edge of the transparent layer by screen printing or spraying.

[0077] In one possible implementation, step S302 includes: forming a light-shielding portion at the edge position of the first side of the transparent layer, wherein a release film and a carrier film are sequentially disposed on the second side of the transparent layer.

[0078] S303. Fix the transparent layer with the light-shielding portion to the side of the 1 / 4λ phase difference film opposite to the polarizing layer.

[0079] In one possible implementation, if step S302 includes "forming a light-shielding portion at the edge position of the first side of the transparent layer, wherein a release film and a carrier film are sequentially disposed on the second side of the transparent layer", then step S303 includes: bonding and fixing the first side of the transparent layer with the light-shielding portion to the side of the 1 / 4λ phase difference film opposite to the polarizing layer by an adhesive layer, and peeling the release film together with the carrier film from the second side of the transparent layer.

[0080] In a specific example, such as Figure 4 As shown, the above implementation involves first printing or spraying the ink light-blocking portion onto the first side (below) of the transparent layer 101 (wherein, a release film 301 and a carrier film 302, such as a PET carrier film, are sequentially disposed on the second side (above) of the transparent layer 101). Then, the ink light-blocking portion and the transparent layer 101 are integrally transferred onto an integrated structure including a flexible cover plate 104 and a polarizing functional film layer (the polarizing functional film layer includes at least a polarizing layer 103 and a 1 / 4λ phase retardation film 102). (The first side of the transparent layer 101 is bonded to the 1 / 4λ phase retardation film 102 via an adhesive layer. Further, before bonding, the ink light-blocking portion at the edge of the first side surface of the transparent layer 101 and the exposed first side surface can be subjected to plasma treatment to improve surface adhesion). The release film 301, along with the carrier film 302, is peeled off from the second side of the transparent layer 101, ultimately forming a structure as shown. Figure 1The structure of the cover plate structure 100 shown, from the transparent layer 101 to the flexible cover plate 104, is prepared using a transfer process in this embodiment.

[0081] If the transparent layer is first fixed to an integrated structure including a flexible cover plate and a polarizing functional film, and then the ink-shielding part is printed or sprayed onto the transparent layer, the heat curing (or baking) of the ink-shielding part during the screen printing or spraying process will cause shrinkage of the polarizing layer and other films in the integrated structure, resulting in product defects. However, this embodiment avoids these product defects by first printing or spraying the ink-shielding part onto the transparent layer, and then transferring the ink-shielding part and the transparent layer together onto an integrated structure including a flexible cover plate and a polarizing functional film (the polarizing functional film includes at least a polarizing layer and a 1 / 4λ phase retardation film). This improves product yield and has advantages such as simple process, making it suitable for mass production.

[0082] Those skilled in the art should understand that although the above steps are described in the order of S301-S303, it does not mean that they must be executed in this order. For example, S302 can be executed first, followed by S301, as long as it does not violate the logic.

[0083] like Figure 5 As shown, another embodiment of the present invention provides a method for fabricating a cover plate structure for a flexible OLED display panel, comprising the following steps:

[0084] S501. A polarizing layer is formed on one side of the flexible cover plate, and a 1 / 4λ phase retardation film is formed on the side of the polarizing layer opposite to the flexible cover plate.

[0085] In a specific example, in step S501, a polarizing layer can be first bonded to one side (below) of the flexible cover plate, and then a 1 / 4λ phase retardation film can be bonded to the side (below) of the polarizing layer opposite to the flexible cover plate. Alternatively, a 1 / 4λ phase retardation film can be bonded to one side (below) of the polarizing layer, and a flexible cover plate can be bonded to the other side (above) of the polarizing layer. Step S301 yields an integrated structure including a flexible cover plate and a polarizing functional film layer (the polarizing functional film layer includes a polarizing layer and a 1 / 4λ phase retardation film).

[0086] S502, A transparent layer is formed on the side of the 1 / 4λ phase difference film facing away from the polarizing layer, and a light-shielding portion is formed at the edge of the transparent layer.

[0087] In one possible implementation, forming a light-shielding portion at the edge of the transparent layer in step S502 includes forming an ink light-shielding portion at the edge of the transparent layer by screen printing or spraying.

[0088] Furthermore, in one possible implementation, the curing process of the ink-shielding portion in the screen printing or spraying process employs a photocuring process, wherein the photocuring process is, for example, a UV curing (ultraviolet curing) process.

[0089] If the transparent layer is first fixed to the integrated structure including the flexible cover plate and the polarizing functional film layer, and then the ink-shielding part is printed or sprayed onto the transparent layer, the heat curing (or baking) of the ink-shielding part during the screen printing or spraying process will cause the polarizing layer and other film layers in the integrated structure to shrink, resulting in product defects. However, this embodiment uses a photocuring process for curing the ink-shielding part during the screen printing or spraying process, which avoids the aforementioned product defects, improves product yield, and has advantages such as simple process, making it suitable for mass production.

[0090] It should be noted that the cover plate structure prepared by the preparation methods provided in the above two embodiments is the same as the cover plate structure in the flexible OLED display module provided in the foregoing embodiments. For relevant details, please refer to the foregoing description, and will not be repeated here.

[0091] After the cover plate structure 100 is prepared by the preparation method provided in the above two embodiments, the cover plate structure 100 can be bonded to the light-emitting side of the flexible OLED display panel 200 by pressure-sensitive adhesive 300 to realize the preparation of the flexible OLED display module.

[0092] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0093] It should also be noted that in the description of this invention, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0094] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A cover plate structure for an OLED display panel, characterized in that, The cover plate structure includes a transparent layer, a 1 / 4λ phase difference film, a polarizing layer and a cover plate stacked together. A light-shielding part is formed at the edge of the transparent layer. The light-shielding part is an ink light-shielding part. The transparent layer with the ink-shielding portion is bonded and fixed to the side of the 1 / 4λ phase retardation film opposite to the polarizing layer by an adhesive layer. The thickness of the transparent layer is 2μm to 20μm. The transparent layer is formed on the side of the 1 / 4λ phase retardation film facing away from the polarizing layer. The transparent layer is in direct contact with the 1 / 4λ phase retardation film. The ink light-shielding part is formed at the edge of the transparent layer by screen printing or spraying. The curing process of the ink light-shielding part in the screen printing or spraying process adopts a photocuring process. The thickness of the transparent layer is 0.5μm~10μm. The cover plate structure also includes an ultrathin glass disposed on the side of the transparent layer opposite to the 1 / 4λ phase difference film, the ultrathin glass being made of inorganic material.

2. The cover plate structure according to claim 1, characterized in that, The transparent layer is an organic polymer material transparent layer.

3. The cover plate structure according to claim 2, characterized in that, The transparent layer of the organic polymer material is an acrylic-based transparent layer.

4. The cover plate structure according to claim 1, characterized in that, The cover plate structure also includes a 1 / 2λ phase retardation film disposed between the 1 / 4λ phase retardation film and the polarizing layer.

5. The cover plate structure according to claim 4, characterized in that, The 1 / 4λ phase retardation film and the 1 / 2λ phase retardation film are liquid crystal phase retardation films, respectively.

6. The cover plate structure according to claim 4, characterized in that, The 1 / 4λ phase retardation film and the 1 / 2λ phase retardation film, the 1 / 2λ phase retardation film and the polarizing layer, and the polarizing layer and the cover plate are respectively bonded and fixed by adhesive layers.

7. The cover plate structure according to claim 1, characterized in that, The polarizing layer is a polyvinyl alcohol polarizing layer.

8. The cover plate structure according to claim 1, characterized in that, The cover plate is a flexible cover plate.

9. An OLED display module, comprising an OLED display panel and a cover plate structure as described in any one of claims 1-8 disposed on the light-emitting side of the OLED display panel.

10. The OLED display module according to claim 9, characterized in that, The cover plate structure is bonded to the light-emitting side of the OLED display panel using pressure-sensitive adhesive.

11. A method for fabricating a cover plate structure for an OLED display panel, characterized in that, include: A polarizing layer is formed on one side of the cover plate, and a 1 / 4λ phase retardation film is formed on the side of the polarizing layer opposite to the cover plate. A light-blocking section is formed at the edge of the transparent layer; A transparent layer with a light-shielding portion is fixed to the side of the 1 / 4λ phase difference film facing away from the polarizing layer. The light-shielding portion is an ink light-shielding portion, and the thickness of the transparent layer is 2μm~20μm. or A polarizing layer is formed on one side of a cover plate, and a 1 / 4λ phase retardation film is formed on the side of the polarizing layer facing away from the cover plate. A transparent layer is formed on the side of the 1 / 4λ phase retardation film facing away from the polarizing layer. The transparent layer is in direct contact with the 1 / 4λ phase retardation film. An ink light-shielding part is formed at the edge of the transparent layer by screen printing or spraying. The curing process of the ink light-shielding part in the screen printing or spraying process adopts a photocuring process. The thickness of the transparent layer is 0.5μm~10μm. An ultrathin glass is formed on the side of the transparent layer opposite to the 1 / 4λ phase reversal film, and the ultrathin glass is made of inorganic material.

12. The preparation method according to claim 11, characterized in that, The formation of a light-shielding portion at the edge of the transparent layer includes: An ink-shielding portion is formed at the edge of the transparent layer using screen printing or spraying processes.

13. The preparation method according to claim 11, characterized in that, The formation of a light-shielding portion at the edge of the transparent layer includes: A light-shielding portion is formed at the edge of the first side of the transparent layer, wherein a release film and a carrier film are sequentially disposed on the second side of the transparent layer; The step of fixing the transparent layer with the light-shielding portion to the side of the 1 / 4λ phase retardation film opposite to the polarizing layer includes: The first side of the transparent layer with the light-shielding portion is bonded and fixed to the side of the 1 / 4λ phase difference film opposite to the polarizing layer by an adhesive layer, and the release film along with the carrier film is peeled off from the second side of the transparent layer.

Images