Foldable display panel and foldable display apparatus

Abstract

The embodiments of the present disclosure relate to the technical field of display. Provided are a foldable display panel and a foldable display apparatus, which are used for improving the definition of photographing and imaging. The foldable display panel comprises an active area and a light-transmitting area. The foldable display panel further comprises a display substrate, a transparent cover plate, a first buffer layer, a first protective layer and a first light-shielding layer. The transparent cover plate is located on a light-emergent side of the display substrate. The first buffer layer is located between the transparent cover plate and the display substrate. The first protective layer is located on the side of the transparent cover plate away from the first buffer layer, and the elastic modulus of the first protective layer is greater than that of the first buffer layer. The first light-shielding layer is located between the transparent cover plate and the display substrate. The first light-shielding layer surrounds at least part of the light-transmitting area, and comprises a first opening region. The orthographic projection of the light-transmitting area on the transparent cover plate at least partially overlaps with the orthographic projection of the first opening region on the transparent cover plate. The foldable display panel is used for displaying images.

Description

Foldable display panel and foldable display device

[0001] This application claims priority to Chinese patent application No. 202311110585.8, filed on August 30, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present disclosure relates to the field of display technology, and in particular to a foldable display panel and a foldable display device. Background Art

[0003] OLED (Organic Light Emitting Diode) display devices have become one of the most competitive and promising display devices due to their advantages such as self-luminescence, fast response speed, high brightness, full viewing angle, and flexible display.

[0004] Summary of the Invention

[0005] In one aspect, a foldable display panel is provided. The foldable display panel includes a display area and a light-transmitting area. The foldable display panel also includes a display substrate, a transparent cover, a first buffer layer, a first protective layer, and a first light-shielding layer. The display substrate includes a via area, the via area being located within the light-transmitting area. The transparent cover is located on the light-emitting side of the display substrate. The first buffer layer is located between the transparent cover and the display substrate. The first protective layer is located on a side of the transparent cover away from the first buffer layer. The material of the first protective layer is different from that of the first buffer layer, and the elastic modulus of the first protective layer is greater than that of the first buffer layer. The first light-shielding layer is located between the transparent cover and the display substrate, and the first light-shielding layer is located between the first buffer layer and the transparent cover, or between the first buffer layer and the display substrate. The first light-shielding layer surrounds at least a portion of the light-transmitting area. The first light-shielding layer includes a first opening area. The orthographic projection of the light-transmitting area on the transparent cover at least partially overlaps with the orthographic projection of the first opening area on the transparent cover.

[0006] In some embodiments, the foldable display panel further includes a second buffer layer. The second buffer layer is located between the transparent cover plate and the first buffer layer. The material of the second buffer layer is different from that of the first buffer layer, and the elastic modulus of the second buffer layer is less than or equal to the elastic modulus of the first buffer layer. The first light-shielding layer is located between the second buffer layer and the transparent cover plate, or between the second buffer layer and the first buffer layer.

[0007] In some embodiments, the elastic modulus of the second buffer layer ranges from 5 MPa to 100 MPa.

[0008] In some embodiments, the thickness of the second buffer layer ranges from 50 μm to 200 μm.

[0009] In some embodiments, the thickness of the second buffer layer ranges from 80 μm to 120 μm.

[0010] In some embodiments, the foldable display panel further comprises an encapsulation layer and a color filter structure layer. The encapsulation layer is located on the side of the display substrate closest to the transparent cover. The color filter structure layer is located on the side of the encapsulation layer closest to the transparent cover. The color filter structure layer comprises a black matrix layer and color filter units, wherein the black matrix layer includes a plurality of spaced-apart second opening regions extending through the black matrix layer, and the color filter units are located within the second opening regions. The first light-shielding layer and the black matrix layer are co-layered.

[0011] In some embodiments, the foldable display panel further includes a bending region on one side of the display region. The first buffer layer includes a first side edge and a second side edge disposed opposite each other, with the first side edge located on the side of the second side edge closer to the bending region. The first side edge includes a first line segment, a first arcuate transition segment, a second line segment, a second arcuate transition segment, and a third line segment connected in sequence. The second line segment protrudes toward the second side edge and defines a groove structure having a rounded bottom corner. The groove structure is located within the bending region.

[0012] In some embodiments, the elastic modulus of the first protective layer ranges from 5.5 GPa to 7.5 GPa.

[0013] In some embodiments, the first protective layer includes a protective substrate, the material of the protective substrate includes transparent polyimide, and the thickness of the transparent polyimide ranges from 50 μm to 80 μm.

[0014] In some embodiments, the thickness of the transparent polyimide ranges from 70 μm to 80 μm.

[0015] In some embodiments, the first protective layer further includes a hard coating layer, and the hard coating layer is located on a side of the protective substrate away from the display substrate.

[0016] In some embodiments, the thickness of the hard coating layer ranges from 5 μm to 20 μm.

[0017] In some embodiments, the elastic modulus of the first buffer layer ranges from 3.5 GPa to 4.5 GPa.

[0018] In some embodiments, the thickness of the first buffer layer ranges from 20 μm to 100 μm.

[0019] In some embodiments, the thickness of the first buffer layer ranges from 20 μm to 50 μm.

[0020] In some embodiments, the first light shielding layer includes a first opening area, and the orthographic projection of the light-transmitting area on the transparent cover covers the orthographic projection of the first opening area on the transparent cover.

[0021] In some embodiments, the foldable display panel further includes a second light-shielding layer, which is located on a side of the first protective layer close to the display substrate, and the second light-shielding layer surrounds at least a portion of the display area.

[0022] In some embodiments, the second light-shielding layer and the first light-shielding layer are in the same layer.

[0023] In some embodiments, the first protection layer includes a groove, the groove surrounding at least a portion of the light-transmitting area. The display panel further includes a third light-shielding layer, the third light-shielding layer being located in the groove.

[0024] In another aspect, a foldable display device is provided, comprising: a foldable display panel as described in any of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] To more clearly illustrate the technical solutions of the present disclosure, the following briefly introduces the drawings required for use in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below are schematic diagrams and are not intended to limit the actual dimensions of the products, actual processes of the methods, actual timing of signals, and the like involved in the embodiments of the present disclosure.

[0026] FIG1 is a structural diagram of a foldable display device according to some embodiments;

[0027] FIG2 is a cross-sectional view taken along the line BB' in FIG1;

[0028] FIG3 is a plan view of a foldable display device according to some embodiments;

[0029] FIG4 is a plan view of a foldable display device according to some other embodiments;

[0030] FIG5 is another cross-sectional view taken along line BB' in FIG1;

[0031] FIG6 is a structural diagram of a foldable display device according to yet other embodiments;

[0032] FIG7 is a structural diagram of a foldable display panel according to some embodiments;

[0033] FIG8 is a structural diagram of a foldable display panel according to some other embodiments;

[0034] FIG9 is a structural diagram of a foldable display panel according to yet other embodiments;

[0035] FIG10 is a structural diagram of a foldable display panel according to some possible implementations;

[0036] FIG11 is a structural diagram of a foldable display panel according to yet other embodiments;

[0037] FIG12 is a structural diagram of a foldable display panel according to yet other embodiments;

[0038] FIG13 is a structural diagram of a foldable display panel according to yet other embodiments;

[0039] FIG14 is a plan view of the first buffer layer in FIG6 ;

[0040] FIG15 is a diagram illustrating a film structure of a foldable display panel according to some embodiments;

[0041] FIG16 is a diagram showing a film structure of a foldable display panel according to some other embodiments;

[0042] FIG17 is a diagram showing a film structure of a foldable display panel according to yet other embodiments;

[0043] FIG18 is another structural diagram of a foldable display panel according to some embodiments;

[0044] FIG19 is another structural diagram of a foldable display panel according to some embodiments;

[0045] FIG20 is a diagram showing a film structure of a foldable display panel according to yet other embodiments;

[0046] FIG21 is a diagram showing a film structure of a foldable display panel according to yet other embodiments;

[0047] FIG22 is a diagram showing a film layer structure of a foldable display panel according to yet other embodiments;

[0048] FIG23 is a structural diagram of the cover plate assembly in FIG22;

[0049] FIG24 is a diagram showing a film structure of a foldable display panel according to yet other embodiments;

[0050] FIG25 is a diagram showing a film structure of a foldable display panel according to yet other embodiments;

[0051] FIG26 is a diagram showing a film layer structure of a foldable display panel according to yet other embodiments;

[0052] FIG27 is a diagram showing a film structure of a foldable display panel according to yet other embodiments;

[0053] FIG28 is a structural diagram of a cover plate assembly according to some embodiments;

[0054] FIG29 is a structural diagram of a cover assembly according to some other embodiments. DETAILED DESCRIPTION

[0055] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0056] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and its other forms, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to indicate that the particular features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0057] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0058] When describing some embodiments, the expressions "coupled" and "connected" and their derivatives may be used. The term "connected" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. The term "coupled" indicates, for example, that two or more components are in direct physical or electrical contact. The term "coupled" or "communicatively coupled" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0059] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0060] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0061] As used herein, the term "if" is optionally interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined that" or "if [stated condition or event] is detected" are optionally interpreted to mean "upon determining" or "in response to determining" or "upon detecting [stated condition or event]" or "in response to detecting [stated condition or event]," depending on the context.

[0062] The use of "adapted to" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0063] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0064] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0065] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within an acceptable deviation range, wherein the acceptable deviation range is as determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, that the difference between the two equals is less than or equal to 5% of either one.

[0066] It will be understood that when a layer or element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present therebetween.

[0067] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0068] FIG1 is a structural diagram of a foldable display device according to some embodiments. Referring to FIG1 , some embodiments of the present disclosure provide a foldable display device 200 , which includes a foldable display panel 100 .

[0069] Exemplarily, the foldable display device 200 also includes a frame and other electronic accessories.

[0070] Exemplarily, the foldable display device 200 may be an electroluminescent foldable display device or a photoluminescent foldable display device. In the case where the foldable display device is an electroluminescent foldable display device, the electroluminescent foldable display device may be an organic light-emitting diode (OLED) or a quantum dot light-emitting diode (QLED). In the case where the foldable display device is a photoluminescent foldable display device, the photoluminescent foldable display device may be a quantum dot photoluminescent foldable display device.

[0071] Exemplarily, the foldable display device 200 can be any foldable display device that displays images, whether in motion (e.g., video) or fixed (e.g., still images), and whether text or images. More specifically, it is expected that the foldable display device of the embodiments described can be implemented in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal data assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, video cameras, game consoles, watches, clocks, calculators, television monitors, flat-panel displays, computer monitors, automotive displays (e.g., odometer displays, etc.), navigation systems, cockpit controls and / or displays, displays of camera views (e.g., displays of rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging, and aesthetic structures (e.g., displays of images of jewelry), etc.

[0072] FIG2 is a cross-sectional view taken along line BB' in FIG1 .

[0073] In some embodiments, as shown in Figures 1 and 2, the foldable display device 200 includes a display area (full name in English: Active Area, abbreviated as AA area; also referred to as an effective display area) AA. The display area AA includes a light-transmitting area Q. Here, the light-transmitting area Q is at least a portion of the display area AA in the foldable display panel 100. Figure 1 illustrates an example in which the light-transmitting area Q is located at a position where the display area AA is away from the lower frame of the foldable display panel 100. It is understandable that in other embodiments, the light-transmitting area Q may also be located at a position where the display area AA is close to the lower frame of the foldable display panel 100.

[0074] In some examples, referring to FIG. 1 , the shape of the light-transmitting region Q may be an ellipse. However, the embodiment of the present disclosure is not limited to this shape of the light-transmitting region Q. For example, the shape of the light-transmitting region Q may also be a square or a circle.

[0075] Exemplarily, the light-transmitting area Q may be a camera area or a fingerprint recognition area, etc. The following only takes the light-transmitting area Q as an example of a camera area, and the same is applicable to fingerprint recognition.

[0076] In some examples, referring to FIG. 1 , the foldable display device 200 further includes at least one foldable region W. The foldable region W extends from one side of the foldable display device 200 to the other side opposite thereto, so as to achieve the folding function of the foldable display device 200 .

[0077] Furthermore, the foldable display device 200 described above uses a single-folding structure as an example. That is, the foldable display device 200 is folded only once, and the exposed area of ​​the foldable display device 200 is subsequently halved. However, this is not limiting. The foldable display device 200 can also be configured as a multiple-folding structure, allowing the foldable display device 200 to be subsequently folded into a structure with a smaller exposed area. A single-folding structure may include one foldable area W, while a multiple-folding structure may include two or more foldable areas W. The specific location of the folding portion is not specifically limited.

[0078] FIG. 3 is a plan view of a foldable display device according to some embodiments, and FIG. 4 is a plan view of a foldable display device according to other embodiments.

[0079] In some embodiments, as shown in FIG. 3 and FIG. 4 , the foldable display device 200 further includes a hinge 201 , which is used to bend the foldable display device 200 in the foldable region W to achieve folding and bending of the foldable display device 200 .

[0080] Based on this, the foldable display device 200 also includes a first side V1 and a second side V2 that are opposite each other. The first side V1 includes a first slot V11, and the second side V2 includes a second slot V21. The first slot V11 of the first side V1 and the second slot V21 of the second side V2 are arranged opposite each other. A hinge 201 is located within the first and second slots V11, V21, and engages with the first and second slots V11, V21, to secure the hinge 201.

[0081] It should be noted that the multiple film layers of the cover assembly 101 in the foldable display device 200 can be provided with slots, and the slots of each film layer can form corresponding first slots V11 and second slots V21. For example, the first protective layer, the transparent cover, the first buffer layer, etc.

[0082] In addition, the foldable display device 200 may also be provided with a volume key slot, and a volume key in the foldable display device 200 may be provided. For example, the volume key slot may be located on the first side V1 or the second side V2.

[0083] In some embodiments, as shown in FIG2 , the foldable display panel 100 in the foldable display device 200 includes a cover assembly 101 and a display substrate 102. The cover assembly 101 is located on the light-emitting surface of the display substrate 102 and can be used to protect the display substrate 102.

[0084] In some examples, as shown in FIG2 , the foldable display device 200 further includes a support plate 210 , which is located on the backlight side of the foldable display panel 100 and includes a light-transmitting hole H. The backlight side of the foldable display panel 100 can be understood as the side opposite to the light-emitting side of the foldable display panel 100 .

[0085] With this arrangement, the support plate 210 can support the foldable display panel 100, and the image light can be emitted into the under-screen camera through the light-transmitting hole H, thereby realizing a full-screen design of the foldable display device 200.

[0086] For example, FIG2 illustrates an example in which the boundary of the orthographic projection of the light-transmitting hole H on the cover assembly 101 substantially overlaps with the boundary of the orthographic projection of the light-transmitting area Q on the cover assembly 101. It is understood that in other examples, the orthographic projection of the light-transmitting hole H on the cover assembly 101 may overlap the orthographic projection of the light-transmitting area Q on the cover assembly 101. Alternatively, in yet other examples, the orthographic projection of the light-transmitting hole H on the cover assembly 101 partially overlaps with the orthographic projection of the light-transmitting area Q on the cover assembly 101.

[0087] It should be noted that "substantially overlap" includes absolute overlap and approximate overlap. That is, the floating range of the gap between the orthographic projection boundary of the light-transmitting hole H on the cover assembly 101 and the orthographic projection boundary of the light-transmitting area Q on the cover assembly 101 does not exceed the error threshold. Alternatively, the orthographic projection boundary of the light-transmitting hole H on the cover assembly 101 and the orthographic projection boundary of the light-transmitting area Q on the cover assembly 101 can be considered to relatively "overlap." The ratio of the error threshold to the length of the light-transmitting area Q can be within a range of 1% to 5%.

[0088] In some examples, as shown in FIG. 2 , the support plate 210 may be made of metal materials such as stainless steel (SUS), copper, or titanium alloy.

[0089] For example, the material of the support plate 210 is stainless steel SUS, which can make the support plate 210 have better supporting force, so as to play the role of supporting the foldable display panel 100 and improve the quality of the foldable display device 200.

[0090] In some examples, the thickness of the support plate 210 can range from 80 μm to 200 μm (inclusive). When the thickness of the support plate 210 is within the range of 80 μm to 200 μm, the support plate 210 can have a good supporting force while preventing the support plate 210 from being too heavy, thereby ensuring a good user experience.

[0091] An exemplary thickness of the support plate 210 is approximately 80 μm, 100 μm, 120 μm, 150 μm, or 200 μm. However, the present disclosure is not limited thereto.

[0092] FIG5 is another cross-sectional view taken along line BB' in FIG1 .

[0093] In some embodiments, as shown in FIG5 , the foldable display device 200 further includes a backing film (U-Film) 220 . The backing film 220 is located between the foldable display panel 100 and the support plate 210 , and can provide some support for the foldable display panel 100 .

[0094] In some embodiments, as shown in FIG5 , the backing film 220 may be bonded to the support plate 210 via a first adhesive layer N1 . However, the embodiments of the present disclosure are not limited thereto.

[0095] In some examples, the first adhesive layer N1 may be a polyimide double-sided adhesive (PI), which can be used to securely connect the back film 220 and the support plate 210 to improve the stability of the foldable display device 200 .

[0096] For example, the polyimide double-sided adhesive tape may include a laminated adhesive layer, a polyimide layer, and an adhesive layer. This arrangement can help increase the cohesive force of the polyimide double-sided adhesive tape, thereby improving the stickiness, so as to better fix the back film 220 and the support plate 210.

[0097] FIG6 is a structural diagram of a foldable display device according to yet other embodiments.

[0098] In some embodiments, as shown in FIG6 , the foldable display panel 100 in the foldable display device 200 further includes a bending zone ZZ. The bending zone ZZ is located on one side of the display area AA (e.g., one side; or, for example, all four sides, i.e., including the upper and lower sides and the left and right sides). The following description uses the example of the bending zone ZZ being adjacent to the lower edge of the display area AA.

[0099] In some examples, the foldable display panel 100 further includes a binding region, which is located on the side of the bending zone ZZ away from the display area AA. The binding region of the foldable display panel 100 is bent toward the backlight side of the foldable display panel 100 via the bending zone ZZ. Specifically, the display substrate 102 is bent at the bending zone ZZ. This allows the display panel and driver chip to be bent toward the back of the foldable display panel 100, thereby reducing the overall device structure space and achieving a narrower bezel.

[0100] In some examples, the foldable display device 200 further includes a support block 230 , which may be made of titanium alloy. When the foldable display panel 100 is bent using the bending zone ZZ, the support block 230 may be used to support the foldable display panel 100 .

[0101] In some examples, the foldable display device 200 may further include a double-sided tape N2 located between the support block 230 and the support plate 210. The double-sided tape N2 can not only be used to securely connect the support block 230 and the support plate 210, but also support the foldable display panel 100 (display substrate 102).

[0102] In some examples, the double-sided tape N2 may be polyimide (PI) double-sided tape, which can be used to securely connect the support block 230 and the support plate 210 to improve the stability of the foldable display device 200 .

[0103] For example, the polyimide double-sided tape may include a laminated adhesive layer, a polyimide layer, and an adhesive layer. This arrangement can help increase the cohesive force of the polyimide double-sided tape, thereby improving the sticking force, so as to better fix the support block 230 and the support plate 210.

[0104] In some examples, the foldable display device 200 may further include a bending spacer N3 positioned between the support block 230 and the backing film 220. The bending spacer N3 may support the display substrate 102. Furthermore, the bending spacer N3 may be adhesive so that the bending spacer N3 can be used to securely connect the support block 230 and the backing film 220.

[0105] FIG7 is a structural diagram of a foldable display panel according to some embodiments. Referring to FIG7 , some embodiments of the present disclosure provide a foldable display panel 100 .

[0106] The foldable display panel 100 includes a display area (active area, also referred to as the effective display area) AA, which includes a light-transmitting area Q. The display area AA and light-transmitting area Q in the foldable display panel 100 correspond to the display area AA and light-transmitting area Q in the foldable display device 200. That is, the display area AA in the foldable display panel 100 is the display area AA in the foldable display device 200, and the light-transmitting area Q in the foldable display panel 100 is the light-transmitting area Q in the foldable display device 200.

[0107] The foldable display panel 100 further includes a cover assembly 101 and a display substrate 102. The cover assembly 101 is located on the light-emitting side of the display substrate 102. A transparent cover 10 is located on the light-emitting side of the display substrate 102. The transparent cover 10 in the cover assembly 101 can protect the display substrate 102.

[0108] In some examples, the display substrate 102 may include an array substrate 103 and a light-emitting device layer 104. The array substrate 103 may include a plurality of pixel driving circuits P. The light-emitting device layer 104 is located on a side of the array substrate 103 close to the transparent cover 10. The light-emitting device layer 104 includes a plurality of light-emitting devices O, which are electrically connected to the pixel driving circuits P in the array substrate 103.

[0109] In some examples, the light-emitting device O includes an anode layer, a light-emitting layer, and a cathode layer stacked in sequence. In some examples, an electron transport layer is further disposed between the cathode layer and the light-emitting layer, and a hole transport layer is further disposed between the anode layer and the light-emitting layer.

[0110] For example, the light-emitting device O may be an OLED light-emitting device, but is not limited thereto. The embodiments of the present disclosure do not limit the type of light-emitting device. That is, the light-emitting device O may be any other light-emitting device (e.g., a light-emitting device that emits light through discharge), as long as it can emit light so that the foldable display panel 100 can display an image. For example, the light-emitting device O may also be a Mini LED or a Micro LED.

[0111] In some examples, the plurality of pixel driving circuits P and the plurality of light-emitting devices O may be coupled in a one-to-one correspondence. In other examples, one pixel driving circuit P may be coupled to multiple light-emitting devices O, or multiple pixel driving circuits P may be coupled to one light-emitting device O. Below, the present disclosure uses the coupling of one pixel driving circuit P to one light-emitting device O as an example to schematically illustrate the structure of the foldable display panel 100.

[0112] FIG8 is a structural diagram of a foldable display panel according to some other embodiments.

[0113] In some embodiments, as shown in FIG. 8 , the cover assembly 101 includes a transparent cover 10 , which is located on the light-emitting side of the display substrate 102 . The transparent cover 10 in the cover assembly 101 can protect the display substrate 102 .

[0114] In some embodiments, as shown in FIG8 , the transparent cover 10 is made of ultra-thin glass (UTG). Ultra-thin glass can be bent, curled, or folded, facilitating the folding of flexible display panels. Ultra-thin glass is also much thinner than ordinary glass, which can reduce the thickness of the cover assembly 101 and facilitate device miniaturization.

[0115] Based on this, the foldability, durability and reliability of the cover assembly 101 are improved.

[0116] In some examples, the elastic modulus of the transparent cover plate 10 is in the range of 70 GPa to 80 GPa (inclusive). When the elastic modulus of the transparent cover plate 10 is within the range of 70 GPa to 80 GPa, the transparent cover plate 10 meets the bendability requirements of the foldable display panel 100 while having a high hardness to protect the display substrate 102.

[0117] Illustratively, the elastic modulus of the transparent cover 10 is approximately any one of 70 GPa, 72 GPa, 74 GPa, 76 GPa, 78 GPa or 80 GPa.

[0118] Taking the elastic modulus of the transparent cover plate 10 of approximately 74 GPa as an example, the transparent cover plate 10 not only meets the bendability requirements of the foldable display panel 100 , but also has a high hardness to protect the display substrate 102 .

[0119] It should be noted that due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the elastic modulus error floating range of the transparent cover plate 10 fluctuates within the range of 10%×74GPa, it can also be considered that the elastic modulus of the transparent cover plate 10 satisfies 74GPa.

[0120] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the elastic modulus error floating range of the transparent cover plate 10 fluctuates within the range of 5%×74 GPa, it can also be considered that the elastic modulus of the transparent cover plate 10 satisfies 74 GPa.

[0121] It should be noted that the “value range” mentioned below includes the two endpoint values ​​of the corresponding value range.

[0122] In some examples, the thickness of the transparent cover plate 10 ranges from 25 μm to 70 μm.

[0123] When the thickness of the transparent cover plate 10 is equal to or close to 25 μm, the thickness of the transparent cover plate 10 can be made thinner, which is conducive to the bending of the foldable display panel 100. At the same time, the transparent cover plate 10 has a certain hardness, which can protect the display substrate 102 and meet the clarity requirements of the transparent cover plate 10 in the foldable display panel 100.

[0124] When the thickness of the transparent cover plate 10 is equal to or close to 70 μm, the transparent cover plate 10 can be made thicker, which helps to make the transparent cover plate 10 have better hardness and a better glass feel, thereby ensuring that the transparent cover plate 10 has higher clarity and achieves the effect of long-term protection of the display substrate 102. At the same time, the transparent cover plate 10 has a certain degree of flexibility to meet the bendability requirements of the foldable display panel 100.

[0125] In other examples, the thickness of the transparent cover plate 10 ranges from 30 μm to 50 μm.

[0126] When the thickness of the transparent cover plate 10 is equal to or close to 30 μm, the transparent cover plate 10 can have a better bending effect. At the same time, the transparent cover plate 10 has a certain hardness, which can protect the display substrate 102 and meet the clarity requirements of the transparent cover plate 10 in the foldable display panel 100.

[0127] When the thickness of the transparent cover plate 10 is equal to or close to 50 μm, the transparent cover plate 10 can have good hardness and a good glass feel, thereby ensuring high clarity and achieving long-term protection for the display substrate 102. At the same time, the transparent cover plate 10 has a certain degree of flexibility to meet the bendability requirements of the foldable display panel 100.

[0128] In some embodiments, referring to FIG. 8 , the thickness of the transparent cover 10 is approximately 25 μm, 30 μm, 40 μm, or 50 μm.

[0129] Taking the thickness of the transparent cover plate 10 as an example, when the thickness of the transparent cover plate 10 is approximately 50 μm, the transparent cover plate 10 can not only meet the clarity requirements of the foldable display panel 100 for the transparent cover plate 10, but also make the transparent cover plate 10 have a certain hardness and a certain flexibility, so as to meet the bendability requirements of the foldable display panel 100 for the transparent cover plate 10, while also protecting the display substrate 102.

[0130] It should be noted that, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error fluctuation range of the thickness of the transparent cover plate 10 fluctuates within the range of 10%×50μm, it can also be considered that the thickness of the transparent cover plate 10 satisfies the requirement of being equal to 50μm.

[0131] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error fluctuation range of the thickness of the transparent cover plate 10 fluctuates within the range of 5%×50μm, it can also be considered that the thickness of the transparent cover plate 10 satisfies the requirement of being equal to 50μm.

[0132] However, the thickness of the transparent cover plate 10 is not limited to this in the embodiment of the present disclosure. In other embodiments, the cover plate assembly 101 may include other film layers. In this case, the thickness of the transparent cover plate 10 can be adjusted according to the specific structure of the cover plate assembly 101. The structure of the cover plate assembly 101 will be described in conjunction with the accompanying drawings below.

[0133] Since the surface strength of the transparent cover plate 10 in the cover plate assembly 101 is insufficient, the transparent cover plate 10 is prone to cracking when the foldable display panel 100 is bent.

[0134] Based on the above problem, in some embodiments, as shown in FIG8 , the cover assembly 101 in the foldable display panel 100 may further include a first protective layer 30 , and the first protective layer 30 is located on the side of the transparent cover 10 away from the display substrate 102 .

[0135] Based on this, the transparent cover plate 10 can be covered with the first protective layer 30 so that the first protective layer 30 can protect the transparent cover plate 10 , thereby making the cover plate assembly 101 have better hardness and impact resistance.

[0136] In some embodiments, the elastic modulus of the first protective layer 30 ranges from 3.5 GPa to 7 GPa.

[0137] When the elastic modulus of the first protective layer 30 is equal to or close to 3.5 GPa, the first protective layer 30 can meet the bending requirements of the foldable display panel 100 , and the first protective layer 30 also has good impact resistance, playing a role in protecting the display substrate 102 .

[0138] When the elastic modulus of the first protective layer 30 is equal to or close to 7 GPa, the first protective layer 30 can have better cushioning and recovery properties, thereby making the first protective layer 30 more impact-resistant and thus better protecting the display substrate 102. At the same time, the elastic modulus of the first protective layer 30 will not be too large, thereby preventing the bending of the foldable display panel 100 from being affected.

[0139] In some examples, the elastic modulus of the first protective layer 30 ranges from 5.5 GPa to 7.5 GPa.

[0140] When the elastic modulus of the first protective layer 30 is equal to or close to 5.5 GPa, the first protective layer 30 can have better buffering and recovery performance, and can have better impact resistance without affecting the bending requirements of the foldable display panel 100.

[0141] When the elastic modulus of the first protective layer 30 is equal to or close to 7.5 GPa, the first protective layer 30 can have better cushioning and recovery properties, thereby making the first protective layer 30 more impact-resistant. At the same time, the elastic modulus of the first protective layer 30 will not be too large, thereby preventing the foldable display panel 100 from bending.

[0142] Illustratively, the elastic modulus of the first protective layer 30 is approximately any one of 5.5 GPa, 6 GPa, 6.2 GPa, 6.5 GPa, 6.8 GPa, 7 GPa, or 7.5 GPa.

[0143] It should be noted that, taking the elastic modulus of the first protective layer 30 as approximately 6.2 GPa as an example, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the elastic modulus of the protective substrate 31 fluctuates within the range of 10%×6.2 GPa, it can also be considered that the elastic modulus of the protective substrate 31 satisfies and is equal to 6.2 GPa.

[0144] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the elastic modulus of the protective substrate 31 fluctuates within the range of 5%×6.2GPa, it can also be considered that the elastic modulus of the protective substrate 31 satisfies and is equal to 6.2GPa.

[0145] FIG. 9 is a structural diagram of a foldable display panel according to yet other embodiments.

[0146] In some embodiments, referring to FIG. 9 , the first protection layer 30 includes a protection substrate 31 , and the material of the protection substrate 31 includes transparent polyimide (CPI).

[0147] A transparent polyimide is formed on the side of the transparent cover plate 10 away from the display substrate 102. The transparent polyimide is used as an impact-resistant layer to disperse the impact stress, thereby protecting the transparent cover plate 10 and preventing the transparent cover plate 10 from breaking when the foldable display panel 100 is impacted by external force.

[0148] In addition, when transparent polyimide is used to form the protective substrate 31 , the elastic modulus of the first protective layer 30 can be approximately 6.2 GPa, which can make the elastic modulus of the first protective layer 30 larger and enable the first protective layer 30 to have better impact resistance.

[0149] The foldable display device 200 includes an inward-folding foldable display device 200 and an outward-folding foldable display device 200. The difference between the inward-folding foldable display device 200 and the outward-folding foldable display device 200 lies in the direction in which the display device 200 bends. For the inward-folding foldable display device 200, the foldable display device 200 folds inward, that is, the foldable display panel 100 is located on the inner side of the support plate. For the outward-folding foldable display device 200, the foldable display device 200 folds outward, that is, the foldable display panel 100 is located on the outer side of the support plate.

[0150] When manufacturing the outward-foldable foldable display device 200, since the transparent cover plate 10 and the display substrate 102 are located on the inner side of the support plate, they will be directly subjected to external force when impacted, and are easily scratched due to long-term exposure to the environment.

[0151] Based on this, a first protective layer 30 with a relatively high elastic modulus (6-7 GPa) can be positioned outside the transparent cover plate 10, display substrate 102, and other structural film layers. In other words, the first protective layer 30 serves as the outermost film layer of the outward-folding foldable display device 200. The first protective layer 30 not only effectively disperses impact stress and effectively protects the transparent cover plate 10, display substrate 102, and other structural film layers, preventing them from cracking, but also prevents scratches on the transparent cover plate 10 and display substrate 102.

[0152] When manufacturing the inward-foldable foldable display device 200, since the transparent cover plate 10, display substrate 102 and other structural film layers are all located on the inner side of the support plate, the transparent cover plate 10, display substrate 102 and other structural film layers will not be directly subjected to force, and the probability of cracking is low.

[0153] Based on this, the elastic modulus requirement for the first protective layer 30 is not as strict as that of the outward-foldable foldable display device 200. The first protective layer 30 in the above-mentioned range of 3.5Gpa to 7Gpa can be used, and transparent polyimide can be used as an impact-resistant layer to disperse the impact stress to protect the transparent cover plate 10 and prevent the transparent cover plate 10 from breaking when the foldable display panel 100 is impacted by external force.

[0154] In summary, the use of the first protective layer 30 with a larger elastic modulus can also make the structure more suitable for the foldable display panel 100 that folds outward.

[0155] It should be noted that due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the elastic modulus of the protective substrate 31 fluctuates within the range of 10%×6.2GPa, it can also be considered that the elastic modulus of the protective substrate 31 satisfies and is equal to 6.2GPa.

[0156] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the elastic modulus of the protective substrate 31 fluctuates within the range of 5%×6.2GPa, it can also be considered that the elastic modulus of the protective substrate 31 satisfies and is equal to 6.2GPa.

[0157] In some examples, the thickness of the protective substrate 31 (transparent polyimide) ranges from 50 μm to 80 μm.

[0158] When the thickness of the protective substrate 31 (transparent polyimide) is equal to or close to 50 μm, the thickness of the protective substrate 31 is thinner, which can make the first protective layer 30 easier to bend and is conducive to the lightweight and thinning of the foldable display panel 100.

[0159] When the thickness of the protective substrate 31 (transparent polyimide) is equal to or close to 80 μm, the thickness of the protective substrate 31 is relatively thick, which can make the first protective layer 30 have better impact resistance and disperse the impact stress, so as to protect the transparent cover plate 10 and prevent the transparent cover plate 10 from breaking when the foldable display panel 100 is impacted by external force.

[0160] In other examples, the thickness of the protective substrate 31 (transparent polyimide) ranges from 70 μm to 80 μm.

[0161] When the thickness of the protective substrate 31 (transparent polyimide) is equal to or close to 70 μm, the first protective layer 30 can be more easily bent, which is conducive to making the foldable display panel 100 lighter and thinner.

[0162] When the thickness of the protective substrate 31 (transparent polyimide) is equal to or close to 80 μm, the first protective layer 30 can have better impact resistance, thereby preventing the transparent cover 10 from breaking when the foldable display panel 100 is subjected to external impact. Furthermore, the first protective layer 30 can also meet the bendability requirements of the foldable display panel 100, thereby adapting to folding the foldable display panel. The foldable display panel can be an inward-folding foldable display panel or an outward-folding foldable display panel.

[0163] Since transparent polyimide has a large elastic modulus, good impact resistance, and good wear resistance, the first protective layer 30 formed based on transparent polyimide is more suitable for foldable display panels that fold outward. However, the embodiments of the present disclosure are not limited thereto.

[0164] In some embodiments, referring to FIG. 9 , the thickness of the protective substrate 31 (transparent polyimide) is approximately 50 μm, 60 μm, 70 μm, or 80 μm.

[0165] It should be noted that, taking the thickness of the protective substrate 31 (transparent polyimide) as approximately 80 μm as an example, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the thickness of the protective substrate 31 (transparent polyimide) fluctuates within the range of 10%×80 μm, it can also be considered that the thickness of the protective substrate 31 (transparent polyimide) satisfies and is equal to 80 μm.

[0166] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the thickness of the protective substrate 31 (transparent polyimide) fluctuates within the range of 5%×80μm, it can also be considered that the thickness of the protective substrate 31 (transparent polyimide) satisfies the requirement of being equal to 80μm.

[0167] The above description, combined with the relevant drawings, illustrates that the material of the protective substrate 31 includes the first protective layer 30 of transparent polyimide (CPI). However, the material of the protective substrate 31 in the disclosed embodiments is not limited thereto. It is understood that in other embodiments, the material of the protective substrate 31 may be polyethylene terephthalate (PET).

[0168] Among them, whether it is transparent polyimide CPI or polyethylene terephthalate PET material, both have high transparency, which can prevent the first protective layer 30 formed based on this from affecting the transmittance of the foldable display panel 100.

[0169] In some embodiments, the elastic modulus of polyethylene terephthalate (PET) ranges from 3.5 GPa to 4.5 GPa.

[0170] When the elastic modulus of polyethylene terephthalate (PET) is equal to or close to 3.5 GPa, the first protective layer 30 (polyethylene terephthalate (PET)) can meet the bending requirements of the foldable display panel 100, and the first protective layer 30 (polyethylene terephthalate (PET)) also has good impact resistance, thereby protecting the display substrate 102.

[0171] When the elastic modulus of the first protective layer 30 is equal to or close to 4.5 GPa, the first protective layer 30 (polyethylene terephthalate PET) can have better cushioning and recovery properties, thereby making the first protective layer 30 (polyethylene terephthalate PET) have better impact resistance, thereby better protecting the display substrate 102. At the same time, the elastic modulus of the first protective layer 30 (polyethylene terephthalate PET) will not be too large, thereby preventing the bending of the foldable display panel 100 from being affected.

[0172] In some examples, the elastic modulus of polyethylene terephthalate (PET) is approximately any one of 3.5 GPa, 3.8 GPa, 4 GPa, 4.2 GPa, or 4.5 GPa. However, the embodiments of the present disclosure are not limited thereto.

[0173] Taking the elastic modulus of the first protective layer 30 (polyethylene terephthalate PET) as an example, which is approximately 4 GPa, the elastic modulus of the first protective layer 30 formed of polyethylene terephthalate can be kept small, making the structure more suitable for the inward-folding foldable display panel 100.

[0174] It should be noted that due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the elastic modulus of the protective substrate 31 fluctuates within the range of 10%×4GPa, it can also be considered that the elastic modulus of the protective substrate 31 satisfies the requirement of being equal to 4GPa.

[0175] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the elastic modulus of the protective substrate 31 fluctuates within the range of 5%×4GPa, it can also be considered that the elastic modulus of the protective substrate 31 satisfies the requirement of being equal to 4GPa.

[0176] In some examples, the thickness of the protective substrate 31 (polyethylene terephthalate) ranges from 20 μm to 100 μm.

[0177] When the thickness of the protective substrate 31 (polyethylene terephthalate) is equal to or close to 20 μm, the protective substrate 31 is thinner, which can make the first protective layer 30 easier to bend and is conducive to the lightweight and thinning of the foldable display panel 100.

[0178] When the thickness of the protective substrate 31 (polyethylene terephthalate) is equal to or close to 100 μm, the thickness of the protective substrate 31 is relatively thick, which can make the first protective layer 30 have better impact resistance and disperse the impact stress, so as to protect the transparent cover plate 10 and prevent the transparent cover plate 10 from breaking when the foldable display panel 100 is impacted by external force.

[0179] In other examples, the thickness of the protective substrate 31 (polyethylene terephthalate) ranges from 40 μm to 80 μm.

[0180] When the thickness of the protective substrate 31 (polyethylene terephthalate) is equal to or close to 40 μm, the first protective layer 30 can be more easily bent, which is beneficial for making the foldable display panel 100 lighter and thinner.

[0181] When the thickness of the protective substrate 31 (polyethylene terephthalate) is equal to or close to 80 μm, the first protective layer 30 can have better impact resistance, thereby preventing the transparent cover 10 from breaking when the foldable display panel 100 is subjected to external impact. Furthermore, the first protective layer 30 can also meet the bendability requirements of the foldable display panel 100, thereby adapting to folding the foldable display panel. The foldable display panel can be an inward-folding foldable display panel or an outward-folding foldable display panel.

[0182] In some embodiments, referring to FIG. 11 , the thickness of the protective substrate 31 (polyethylene terephthalate) is approximately 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 65 μm, 70 μm, 80 μm, 90 μm, or 100 μm.

[0183] It should be noted that, taking the thickness of the protective substrate 31 (polyethylene terephthalate) as approximately 65 μm as an example for explanation, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the thickness of the protective substrate 31 (polyethylene terephthalate) fluctuates within the range of 10%×65 μm, it can also be considered that the thickness of the protective substrate 31 (polyethylene terephthalate) satisfies and is equal to 65 μm.

[0184] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the thickness of the protective substrate 31 (polyethylene terephthalate) fluctuates within the range of 5%×65μm, it can also be considered that the thickness of the protective substrate 31 (polyethylene terephthalate) satisfies and is equal to 65μm.

[0185] The thickness of the protective substrate 31 (polyethylene terephthalate) is set to about 65 μm, which can not only make the first protective layer 30 have a certain impact resistance, but also make the first protective layer 30 have a certain flexibility, so that the first protective layer 30 can protect the transparent cover 10 while meeting the bendability requirements of the foldable display panel 100.

[0186] In addition, since the protective substrate 31 (polyethylene terephthalate) is provided with a thickness of approximately 65 μm, compared to the protective substrate 31 (transparent polyimide) provided with a thickness of approximately 80 μm, the thickness of the first protective layer 30 can be made thinner, making the first protective layer 30 more suitable for the inward-folding foldable display panel 100. However, the embodiments of the present disclosure are not limited thereto.

[0187] In some embodiments, referring to FIG. 9 , the first protective layer 30 may further protect a hard coating (HC) 32 formed on the side of the protective substrate 31 facing away from the display substrate 102. The hard coating 32 may enhance the surface hardness of the first protective layer 30 facing away from the display substrate 102, thereby improving the surface hardness of the first protective layer 30 facing away from the display substrate 102. This improves the hardness of the cover assembly 101 in the foldable display panel 100 and enhances its reliability.

[0188] In some examples, the thickness of the hardened coating 32 ranges from 5 μm to 20 μm.

[0189] When the thickness of the hardened coating layer 32 is equal to or close to 5 μm, the thickness of the hardened coating layer 32 is relatively thin, so that the first protective layer 30 can have a higher hardness while meeting the requirements of bendability.

[0190] When the thickness of the hardening coating 32 is equal to or close to 20 μm, the thickness of the hardening coating 32 is thicker, which can make the hardness of the first protective layer 30 higher, so as to better protect the transparent cover 10 and also enable the first protective layer 30 to meet the requirements of bendability.

[0191] In other examples, the thickness of the hardened coating 32 ranges from 5 μm to 10 μm.

[0192] When the thickness of the hardening coating layer 32 is equal to or close to 5 μm, the first protective layer 30 can have a higher hardness while meeting the requirements for bendability.

[0193] When the thickness of the hardened coating layer 32 is equal to or close to 10 μm, the hardness of the first protective layer 30 can be increased, thereby better protecting the transparent cover 10 and ensuring that the first protective layer 30 meets the required flexibility. Furthermore, when the thickness of the hardened coating layer 32 is equal to or close to 10 μm, it can also prevent the hardened coating layer 32 from being too thick, which would make existing processes difficult to implement, and prevent the hardened coating layer 32 from having an uneven surface during its formation.

[0194] Illustratively, the thickness of the hardened coating layer 32 is approximately any one of 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm.

[0195] It should be noted that, taking the thickness of the hardened coating 32 of approximately 5 μm as an example for explanation, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the thickness of the hardened coating 32 fluctuates within the range of 10%×5 μm, it can also be considered that the thickness of the hardened coating 32 satisfies the requirement of being equal to 5 μm.

[0196] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error fluctuation range of the thickness of the hardened coating 32 fluctuates within the range of 5%×5μm, it can also be considered that the thickness of the hardened coating 32 satisfies the requirement of being equal to 5μm.

[0197] In some embodiments, when the material of the protective substrate 31 in the first protective layer 30 is transparent polyimide, the thickness of the hardening coating 32 is about 9 μm.

[0198] For example, the thickness of the protective substrate 31 (transparent polyimide) is approximately 80 μm, and the thickness of the hardening coating 32 is approximately 9 μm. This allows the first protective layer 30 to have better impact resistance and wear resistance. Based on this, the first protective layer 30 is more suitable for foldable display panels that fold outward. However, the embodiments of the present disclosure are not limited to this.

[0199] In some embodiments, when the material of the protective substrate 31 in the first protective layer 30 is polyethylene terephthalate, the thickness of the hardening coating layer 32 is about 5 μm.

[0200] For example, when the thickness of the protective substrate 31 (polyethylene terephthalate) is approximately 650 μm and the thickness of the hardening coating 32 is approximately 5 μm, the first protective layer 30 can have better impact resistance, thereby preventing the transparent cover 10 from breaking when the foldable display panel 100 is impacted by external forces. In addition, compared with a protective substrate 31 (transparent polyimide) of approximately 80 μm, the thickness of the first protective layer 30 can be made thinner, making the first protective layer 30 more suitable for the foldable display panel 100 that folds inward. However, the embodiments of the present disclosure are not limited to this.

[0201] In some embodiments, as shown in FIG8 , the cover assembly 101 of the foldable display panel 100 may further include a first buffer layer 40. The first buffer layer 40 is located on the side of the transparent cover 10 close to the display substrate 102, that is, the transparent cover 10 is located between the first protective layer 30 and the first buffer layer 40.

[0202] Since the first buffer layer 40 has good buffering and recovery properties, it can play a good role in buffering and shock absorption. In addition, the first buffer layer 40 can effectively absorb a part of the bending stress and can also protect the transparent cover plate 10 to a certain extent, preventing it from breaking when the foldable display panel 100 is impacted by external force.

[0203] That is, the transparent cover plate 10 is sandwiched between the first protective layer 30 and the first buffer layer 40 , and the first protective layer 30 and the first buffer layer 40 can be used to protect the transparent cover plate 10 and prevent the transparent cover plate 10 from being broken.

[0204] In some examples, the first protective layer 30 is closer to the outside of the foldable display panel 100 than the transparent cover 10 and the first buffer layer 40. Therefore, when the foldable display panel 100 is impacted by an external force, the first protective layer 30 is subjected to the greatest impact force.

[0205] Furthermore, the material of the first buffer layer 40 may be different from that of the first protective layer 30 , so that the elastic modulus of the first protective layer 30 is greater than that of the first buffer layer 40 .

[0206] Based on this, a first protective layer 30 with a higher elastic modulus is positioned on the outer side of the foldable display panel 100, while a first buffer layer 40 with a relatively lower elastic modulus is positioned on the inner side of the foldable display panel 100. The first protective layer 30 with a higher elastic modulus is impacted first, and its superior impact resistance provides excellent shock absorption, preventing cracking of the transparent cover plate 10. Simultaneously, the first buffer layer 40 also provides shock absorption and effectively absorbs some bending stress, thus providing a certain degree of protection for the transparent cover plate 10.

[0207] In some examples, the material of the first buffer layer 40 can be polyethylene terephthalate (PET). Based on this, the elastic modulus of the first buffer layer 40 is approximately 4 GPa. The high elastic modulus of the first buffer layer 40 can provide good cushioning and recovery properties, effectively absorb a portion of the bending stress, and provide good cushioning and shock absorption.

[0208] In some examples, the thickness of the first buffer layer 40 ranges from 20 μm to 100 μm.

[0209] When the thickness of the first buffer layer 40 is equal to or close to 20 μm, the first buffer layer 40 is thinner, which can make the first buffer layer 40 easier to bend and is conducive to making the foldable display panel 100 lighter and thinner.

[0210] When the thickness of the first buffer layer 40 is equal to or close to 100 μm, the first buffer layer 40 is thicker, which can make the first buffer layer 40 have better impact resistance and disperse the impact stress, so as to protect the transparent cover plate 10 and prevent the transparent cover plate 10 from breaking when the foldable display panel 100 is impacted by external force.

[0211] In some other examples, the thickness of the first buffer layer 40 ranges from 20 μm to 50 μm.

[0212] When the thickness of the first buffer layer 40 is equal to or close to 20 μm, the first buffer layer 40 can be bent more easily, which is beneficial for making the foldable display panel 100 lighter and thinner.

[0213] When the thickness of the first buffer layer 40 is equal to or close to 50 μm, the first buffer layer 40 can have better impact resistance, thereby preventing the transparent cover plate 10 from breaking when the foldable display panel 100 is impacted by an external force.

[0214] In some embodiments, referring to FIG. 8 , the thickness of the first buffer layer 40 is approximately 20 μm, 23 μm, 25 μm, 30 μm, 40 μm, 50 μm, 60 μm, 65 μm, 70 μm, 80 μm, 90 μm, or 100 μm.

[0215] Taking the thickness of the first buffer layer 40 as about 23 μm as an example, the first buffer layer 40 is not too thick to affect the bending of the foldable display panel 100 , and can also effectively disperse the impact stress and protect the transparent cover 10 .

[0216] It should be noted that due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the thickness of the first buffer layer 40 fluctuates within the range of 10%×23μm, it can also be considered that the thickness of the first buffer layer 40 satisfies the requirement of being equal to 65μm.

[0217] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the thickness of the first buffer layer 40 fluctuates within the range of 5%×23μm, it can also be considered that the thickness of the first buffer layer 40 satisfies the requirement of being equal to 23μm.

[0218] In some embodiments, as shown in FIG8 , the cover assembly 101 of the foldable display panel 100 may further include multiple adhesive layers disposed between two adjacent film layers in the cover assembly 101 to secure the two film layers. One of the multiple adhesive layers may be a first adhesive layer F1, which is located between the first protective layer 30 and the transparent cover 10. The first adhesive layer F1 securely connects the first protective layer 30 and the transparent cover 10, thereby improving the stability of the cover assembly 101.

[0219] In some examples, the material of the first adhesive layer F1 can be optically clear adhesive (OCA). Because the optical adhesive OCA has a certain degree of viscosity, it can securely connect the first protective layer 30 and the transparent cover plate 10, thereby improving the stability of the cover plate assembly 101. Furthermore, because the optical adhesive OCA is relatively soft and has a certain degree of elasticity, it can effectively absorb some bending stress and also provide a certain degree of protection for the transparent cover plate 10, preventing it from breaking when the foldable display panel 100 is subjected to external impact.

[0220] In some embodiments, the thickness of the first adhesive layer F1 ranges from 15 μm to 100 μm.

[0221] When the thickness of the first adhesive layer F1 is equal to or close to 15 μm, the first adhesive layer F1 is relatively thin, which can meet the bonding strength requirements of the first adhesive layer F1 and also facilitate the lightweight and thinning of the cover assembly 101, that is, the lightweight and thinning of the foldable display panel 100. In addition, since the thickness of the first adhesive layer F1 is relatively thin and the first adhesive layer F1 (optical adhesive OCA) is relatively soft, the problem of the first adhesive layer F1 causing the cover assembly 101 to be too soft can also be prevented.

[0222] When the thickness of the first adhesive layer F1 is equal to or close to 100 μm, the thicker the first adhesive layer F1, the better the adhesion of the first adhesive layer F1, thereby better fixing the transparent cover plate 10 and the first protective layer 30. Furthermore, due to the thicker thickness of the first adhesive layer F1, the first adhesive layer F1 can also be used to absorb bending stress, thereby protecting the transparent cover plate 10.

[0223] In some examples, the thickness of the first adhesive layer F1 ranges from 30 μm to 80 μm.

[0224] When the thickness of the first adhesive layer F1 is equal to or close to 30 μm, the required adhesive strength of the first adhesive layer F1 can be met, while also contributing to the lightweight and thinning of the cover assembly 101, and thus the lightweight and thinning of the foldable display panel 100. Furthermore, since the first adhesive layer F1 (optical adhesive OCA) is relatively soft, the problem of the first adhesive layer F1 causing the cover assembly 101 to be too soft can be prevented.

[0225] When the thickness of the first adhesive layer F1 is equal to or close to 80 μm, it can help improve the adhesion of the first adhesive layer F1, thereby better fixing the transparent cover plate 10 and the first protective layer 30. In addition, the first adhesive layer F1 can also absorb bending stress and protect the transparent cover plate 10.

[0226] For example, the thickness of the first adhesive layer F1 is about 15 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm, but the present disclosure is not limited thereto.

[0227] Here, the thickness of the first adhesive layer F1 is approximately 50 μm. In this case, the first adhesive layer F1 can meet the bonding strength requirements of the first adhesive layer F1, absorb bending stress, protect the transparent cover plate 10, and prevent the first adhesive layer F1 from causing the cover plate assembly 101 to be too soft.

[0228] It should be noted that due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the thickness of the first adhesive layer F1 fluctuates within the range of 10%×50μm, it can also be considered that the thickness of the first adhesive layer F1 satisfies the requirement of being equal to 50μm.

[0229] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the thickness of the first adhesive layer F1 fluctuates within the range of 5%×50μm, it can also be considered that the thickness of the first adhesive layer F1 satisfies the requirement of being equal to 50μm.

[0230] In some embodiments, since the first adhesive layer F1 fixedly connects the first protective layer 30 and the transparent cover plate 10 and is bonded to the transparent cover plate 10, the first adhesive layer F1 can be configured to be retracted so that the boundary of the orthographic projection of the first adhesive layer F1 on the transparent cover plate 10 is located within the transparent cover plate 10. In other words, this prevents the first adhesive layer F1 from overflowing from the transparent cover plate 10 when the first adhesive layer F1 is used to bond the transparent cover plate 10, thereby improving the quality of the cover plate assembly 101.

[0231] In some examples, the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the transparent cover plate 10 and the boundary of the transparent cover plate 10 is greater than or equal to 0.2 mm.

[0232] When the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the transparent cover plate 10 and the boundary of the transparent cover plate 10 is equal to or close to 0.2 mm, this effectively reserves 0.2 mm of space for the first adhesive layer F1. Because the reserved space is relatively small, it prevents blanking and prevents unstable bonding of parts of the transparent cover plate 10. Furthermore, this reserved space allows for the flow of the first adhesive layer F1, preventing adhesive overflow from the cover plate assembly 101.

[0233] In some other examples, the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the transparent cover plate 10 and the boundary of the transparent cover plate 10 is less than or equal to 0.5 mm.

[0234] When the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the transparent cover plate 10 and the boundary of the transparent cover plate 10 is equal to or close to 0.5 mm, a space of 0.5 mm can be reserved for the first adhesive layer F1. This sufficient reserved space can better prevent glue overflow from occurring on the cover plate assembly 101. Furthermore, the reserved space will not be too large, thereby preventing the problem of blank space.

[0235] In some other examples, the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the transparent cover plate 10 and the boundary of the transparent cover plate 10 ranges from 0.2 mm to 0.5 mm.

[0236] When the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the transparent cover plate 10 and the boundary of the transparent cover plate 10 is within the range of 0.2 mm to 0.5 mm, it can not only meet the flow requirements of the first adhesive layer, but also prevent the problem of blank space, which can be beneficial to improving the quality of the cover plate assembly 101.

[0237] In some other examples, the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the transparent cover plate 10 and the boundary of the transparent cover plate 10 ranges from 0.2 mm to 0.3 mm.

[0238] For example, in some other examples, the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the transparent cover plate 10 and the boundary of the transparent cover plate 10 is approximately 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm. However, the embodiments of the present disclosure are not limited thereto.

[0239] In some embodiments, because the first adhesive layer F1 securely connects the first protective layer 30 and the transparent cover 10, the first adhesive layer F1 is bonded to the first protective layer 30, and the boundary of the orthographic projection of the first adhesive layer F1 on the first protective layer 30 is located within the first protective layer 30. In other words, the first adhesive layer F1 is prevented from overflowing from the first protective layer 30 when being bonded to the first protective layer 30, thereby improving the quality of the cover assembly 101.

[0240] In some examples, the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the first protective layer 30 and the boundary of the first protective layer 30 is greater than or equal to 0.2 mm.

[0241] When the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the first protective layer 30 and the boundary of the first protective layer 30 is equal to or close to 0.2 mm, this effectively leaves 0.2 mm of space for the first adhesive layer F1. Because the reserved space is small, it prevents blanking and unstable bonding of portions of the first protective layer 30. Furthermore, this reserved space allows for the flow of the first adhesive layer F1, preventing adhesive overflow from the cover assembly 101.

[0242] In some other examples, the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the first protective layer 30 and the boundary of the first protective layer 30 is less than or equal to 0.5 mm.

[0243] When the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the first protective layer 30 and the boundary of the first protective layer 30 is equal to or close to 0.5 mm, a space of 0.5 mm can be reserved for the first adhesive layer F1. This sufficient reserved space can better prevent glue overflow from occurring on the cover assembly 101. Furthermore, the reserved space will not be too large, thereby preventing the problem of blank space.

[0244] In some other examples, the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the first protective layer 30 and the boundary of the first protective layer 30 ranges from 0.2 mm to 0.5 mm.

[0245] When the boundary of the positive projection of the first adhesive layer F1 on the first protective layer 30 is spaced from the boundary of the first protective layer 30 within a range of 0.2 mm to 0.5 mm, it can not only meet the flow requirements of the first adhesive layer, but also prevent the problem of blank space, which can be beneficial to improving the quality of the cover assembly 101.

[0246] In some other examples, the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the first protective layer 30 and the boundary of the first protective layer 30 ranges from 0.2 mm to 0.3 mm.

[0247] For example, in some other examples, the distance between the boundary of the orthographic projection of the first adhesive layer F1 on the first protective layer 30 and the boundary of the first protective layer 30 is approximately 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm. However, the embodiments of the present disclosure are not limited thereto.

[0248] In addition, the plurality of adhesive layers may further include other adhesive layers, wherein the “other adhesive layers” may further include a second adhesive layer F2 and a third adhesive layer F3.

[0249] The second adhesive layer F2 is located between the transparent cover plate 10 and the first buffer layer 40 , so as to utilize the second adhesive layer F2 to fix and bond the transparent cover plate 10 and the first buffer layer 40 , thereby improving the stability of the cover plate assembly 101 .

[0250] The third adhesive layer F3 is located between the first buffer layer 40 and the display substrate 102 , so as to utilize the third adhesive layer F3 to securely bond the first buffer layer 40 and the display substrate 102 , thereby improving the stability of the cover assembly 101 .

[0251] It should be noted that the materials for the second adhesive layer F2 and the third adhesive layer F3 can be the same as those for the first adhesive layer F1 described above, and will not be further described here. Furthermore, the materials for the second adhesive layer F2 and the thickness of the third adhesive layer F3, as well as the degree of indentation (the degree to which the adhesive layer indents relative to the film layer to which it is bonded) of each adhesive layer are similar to those for the first adhesive layer F1 described above, and will not be further described here. However, the present disclosure is not limited to these.

[0252] In some embodiments, to meet the requirements of an under-screen camera, a light-transmitting area Q is provided in the foldable display panel 100. The display substrate 102 in the foldable display panel 100 may include an aperture area Q1, and the aperture area Q1 of the display substrate 102 is arranged corresponding to the light-transmitting area Q of the foldable display panel 100. That is, the aperture area Q1 of the display substrate 102 is located within the light-transmitting area Q of the foldable display panel 100. In other words, the space along the thickness direction of the transparent cover 10 along the aperture area Q1 of the display substrate 102 constitutes the light-transmitting area Q of the foldable display panel 100.

[0253] Furthermore, the light-transmitting hole H of the support plate 210 is also located within the light-transmitting area Q of the foldable display panel 100. With this arrangement, image light can pass through the opening area Q1 of the display substrate 102 and the light-transmitting hole H of the support plate 210 and enter a light-sensing element, such as an under-screen camera, thereby achieving a full-screen design for the foldable display device 200.

[0254] FIG. 10 is a structural diagram of a foldable display panel according to some possible implementations.

[0255] In some implementations, please refer to Figure 10. In order to prevent light leakage at the light-transmitting area Q, a first light-shielding layer 20 needs to be added to the foldable display panel 100, and the first light-shielding layer 20 is set to surround at least part of the light-transmitting area Q, so that the first light-shielding layer 20 can be used to block the light around the light-transmitting area Q, so as to improve the light leakage problem at the light-transmitting area Q in the foldable display panel 100.

[0256] Generally, the first light shielding layer 20 is disposed on a side of the transparent cover plate 10 away from the display substrate 102, so that the first light shielding layer 20 can shield the film layer below it. In other words, the first light shielding layer 20 is disposed between the first protective layer 30 and the transparent cover plate 10. Specifically, the first light shielding layer 20 is disposed between the first protective layer 30 and the first adhesive layer F1.

[0257] However, the inventors discovered that because the first light-shielding layer 20 is not a single, continuous layer, and therefore due to its thickness, the first adhesive layer F1 adjacent to the first light-shielding layer 20 is uneven. Specifically, the surface of the first adhesive layer F1 adjacent to the first light-shielding layer 20 protrudes from the surface of the first adhesive layer F1 not adjacent to the first light-shielding layer 20.

[0258] Based on this, the first adhesive layer F1 at the position of the light-transmitting area Q will be uneven, which will cause the peak-to-valley value (PV) at the position of the light-transmitting area Q to be larger (greater than 0.8λ), which will affect the propagation direction of light at the position of the light-transmitting area Q, thereby making the photo imaging blurred and reducing the imaging effect of the foldable display panel 100.

[0259] For example, the PV value at the position of the light-transmitting region Q is greater than or equal to 1.8λ.

[0260] In other feasible implementations, in order to reduce the PV value at the light-transmitting region Q, a thinning process is employed for the first light-shielding layer 20. However, due to the limitations of existing manufacturing processes, the PV value at the light-transmitting region Q can only be reduced to approximately 1.2λ, which is still higher than 0.8λ. This still affects the propagation direction of light at the light-transmitting region Q, resulting in blurred images. In other words, by thinning the first light-shielding layer 20, the PV value at the light-transmitting region Q cannot be reduced to below 0.8λ, which still affects the imaging effect of the foldable display panel 100 and reduces the quality of the foldable display panel 100.

[0261] FIG11 is a structural diagram of a foldable display panel according to yet other embodiments.

[0262] To address the aforementioned issues, as shown in FIG8 , some embodiments of the present disclosure provide a foldable display panel 100 comprising a display area (active area, also referred to as the effective display area) AA and a light-transmitting area Q. The foldable display panel 100 further comprises a cover assembly 101 and a display substrate 102. The cover assembly 101 is located on the light-emitting side of the display substrate 102. The cover assembly 101 comprises a first protective layer 30, a transparent cover 10, and a first buffer layer 40, which are stacked in sequence.

[0263] In some examples, referring to FIG. 8 and FIG. 11 , the first light shielding layer 20 is provided to surround at least a portion of the light-transmitting area Q. The first light shielding layer 20 surrounds at least a portion of the light-transmitting area Q, including the following situations:

[0264] The first type: the first light-shielding layer 20 can be a closed-loop structure, and the first light-shielding layer 20 is arranged around the light-transmitting area Q.

[0265] The second type: the first light-shielding layer 20 may also be a non-closed-loop structure, and the first light-shielding layer 20 is disposed around a portion of the light-transmitting area Q.

[0266] The present disclosure does not specifically limit the above two situations. Both of the above situations can improve the light leakage problem at the position of the light-transmitting area Q. In the following, the first situation is described as an example, in which the first light-shielding layer 20 can be a closed-loop structure and is disposed around the light-transmitting area Q.

[0267] In some examples, the first light-shielding layer 20 includes a first opening area K1, and the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 at least partially overlaps with the orthographic projection of the first opening area K1 on the transparent cover plate 10. Thus, the first light-shielding layer 20 can better block light at the location of the light-transmitting area Q, preventing light leakage at the boundary of the opening area Q of the foldable display panel 100.

[0268] The phrase “the first light-shielding layer 20 includes a first opening area K1, and the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 at least partially overlaps with the orthographic projection of the first opening area K1 on the transparent cover plate 10” includes the following situations:

[0269] The first type: the first light shielding layer 20 includes a first opening area K1 , and the orthographic projection of the light-transmitting area Q on the transparent cover 10 partially overlaps with the orthographic projection of the first opening area K1 on the transparent cover 10 .

[0270] With such a configuration, the first light shielding layer 20 can block the light at the light-transmitting area Q to a certain extent, thereby preventing light leakage at the boundary of the opening area Q of the foldable display panel 100.

[0271] The second type: the first light shielding layer 20 includes a first opening area K1 , and the orthographic projection of the light-transmitting area Q on the transparent cover 10 covers the orthographic projection of the first opening area K1 on the transparent cover 10 .

[0272] By setting the first opening area K1 of the first light-shielding layer 20 in this way, the first light-shielding layer 20 can better block the light at the position of the light-transmitting area Q, thereby preventing light leakage at the boundary position of the opening area Q of the foldable display panel 100.

[0273] The relative positional relationship between the orthographic projection of the light-transmitting area Q on the transparent cover 10 and the orthographic projection of the first opening area K1 on the transparent cover 10 may include the following two situations:

[0274] The first type: please refer to FIG. 8 , the orthographic projection of the first opening area K1 on the transparent cover 10 is located within the orthographic projection of the light-transmitting area Q on the transparent cover 10 .

[0275] Based on this, the first light shielding layer 20 can be extended into the opening area Q, and the portion of the first light shielding layer 20 extending into the opening area Q can be better utilized to block the light at the edge of the opening area Q, thereby improving the problem of light leakage in the opening area Q.

[0276] In some examples, for the first case, a first distance D1 can be set between the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover 10 and the boundary of the orthographic projection of the first opening area K1 on the transparent cover 10, and the value range of the first distance D1 is less than or equal to 0.5 mm.

[0277] When the first distance D1 is equal to or close to 0.5 mm, the portion of the first light-shielding layer 20 extending into the light-transmitting area Q is relatively large, so that the first light-shielding layer 20 can better block light at the edge of the opening area Q, thereby improving the problem of light leakage in the opening area Q. At the same time, the portion of the first light-shielding layer 20 extending into the light-transmitting area Q is not too large, which would cause the problem of affecting the transmittance of the light-transmitting area Q.

[0278] In other examples, the value range of the first distance D1 is less than or equal to 0.2 mm.

[0279] When the first distance D1 is equal to or close to 0.2 mm, the first light shielding layer 20 can be used to block light at the edge of the opening area Q to prevent light leakage from the opening area Q; and the first light shielding layer 20 can be prevented from affecting the transmittance of the light-transmitting area Q.

[0280] For example, the first distance D1 is approximately any one of 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm. However, the embodiments of the present disclosure are not limited thereto.

[0281] The second type: as shown in FIG. 11 , the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover 10 substantially overlaps with the boundary of the orthographic projection of the first opening area K1 on the transparent cover 10 .

[0282] Based on this, the boundary of the first light-shielding layer 20 can be made to coincide with the boundary of the opening area Q, which can block the light at the edge of the opening area Q to improve the problem of light leakage in the opening area Q; and prevent the first light-shielding layer 20 from affecting the transmittance at the light-transmitting area Q, thereby improving the quality of the foldable display panel 100.

[0283] It should be noted that "substantially overlapping" in the second case can include absolute overlap and approximate overlap. That is, the floating range of the gap between the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 and the boundary of the orthographic projection of the first opening area K1 on the transparent cover plate 10 does not exceed the error threshold. Alternatively, the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 and the boundary of the orthographic projection of the first opening area K1 on the transparent cover plate 10 can be considered to relatively "overlap." The ratio of the error threshold to the length of the light-transmitting area Q can be within a range of 1% to 5%.

[0284] Furthermore, the first light-shielding layer 20 can be disposed on the side of the transparent cover plate 10 close to the display substrate 102. This arrangement allows the first light-shielding layer 20 to be further away from the light-emitting surface S1 of the foldable display panel 100 (as shown in FIG8 ). Furthermore, the adhesive layer (the second adhesive layer F2 or the third adhesive layer F3) with an uneven surface after the first light-shielding layer 20 is attached can be further away from the light-emitting surface of the foldable display panel 100 than the first adhesive layer F1.

[0285] Based on this, the first light-shielding layer 20 can be moved toward the side closer to the display substrate 102, thereby being moved to the side of the transparent cover 10 closer to the display substrate 102. This can increase the distance between the first light-shielding layer 20 and the light-emitting surface S1 of the foldable display panel 100, while also increasing the distance between the adhesive layer bonded to the first light-shielding layer 20 and the light-emitting surface S1 of the foldable display panel 100. As a result, the unevenness of the adhesive layer (the second adhesive layer F2 or the third adhesive layer F3) bonded to the first light-shielding layer 20, which is farther away from the light-emitting surface S1 of the foldable display panel 100, has a smaller impact on the PV value at the position of the light-transmitting area Q than the unevenness of the first adhesive layer F1. Thus, the PV value at the position Q of the light-transmitting area can be reduced to below 0.8λ, reducing the impact on the propagation direction of light at the position Q of the light-transmitting area, thereby improving the clarity of the photographic imaging and improving the quality of the foldable display panel 100.

[0286] FIG12 is a structural diagram of a foldable display panel according to yet other embodiments.

[0287] It should be noted that the first light shielding layer 20 is disposed on the side of the transparent cover plate 10 close to the display substrate 102 in the following two cases:

[0288] The first method is to dispose the first light shielding layer 20 between the transparent cover plate 10 and the first buffer layer 40 .

[0289] For example, referring to FIG. 8 , a first light shielding layer 20 may be provided in contact with the transparent cover plate 10 , and the first light shielding layer 20 may be formed between the transparent cover plate 10 and the second adhesive layer F2 .

[0290] For example, the first light shielding layer 20 may not contact the transparent cover plate 10 but contact the first buffer layer 40 , and the first light shielding layer 20 may be formed between the first buffer layer 40 and the second adhesive layer F2 .

[0291] This arrangement allows the first light-shielding layer 20 to be positioned further away from the light-emitting surface of the foldable display panel 100 than if the first light-shielding layer 20 were positioned on the side of the transparent cover plate 10 closer to the display substrate 102. Furthermore, the adhesive layer (second adhesive layer F2) having an uneven surface after the first light-shielding layer 20 is attached can be positioned further away from the light-emitting surface of the foldable display panel 100 than the first adhesive layer F1.

[0292] Based on this, the distance between the first light-shielding layer 20 and the light-emitting surface S1 of the foldable display panel 100 can be increased, and the distance between the adhesive layer bonded to the first light-shielding layer 20 and the light-emitting surface S1 of the foldable display panel 100 can be increased. As a result, the adhesive layer (second adhesive layer F2) bonded to the first light-shielding layer 20 is farther away from the light-emitting surface S1 of the foldable display panel 100 than the first adhesive layer F1. The unevenness of the second adhesive layer F2 has a smaller impact on the PV value at the position of the light-transmitting area Q than the unevenness of the first adhesive layer F1. As a result, the PV value at the position of the light-transmitting area Q can be reduced to below 0.8λ, reducing the impact on the propagation direction of light at the position of the light-transmitting area Q, thereby improving the clarity of the photographic image and improving the quality of the foldable display panel 100.

[0293] The second method is to dispose the first light shielding layer 20 between the first buffer layer 40 and the display substrate 102 .

[0294] Exemplarily, referring to FIG. 12 , the first light shielding layer 20 is not in contact with the transparent cover plate 10 , but in contact with the first buffer layer 40 , and is formed between the first buffer layer 40 and the third adhesive layer F3 .

[0295] Exemplarily, the first light-shielding layer 20 can be set to be not in contact with the transparent cover plate 10, and the first light-shielding layer 20 can be not in contact with the first buffer layer 40, and the first light-shielding layer 20 can be in contact with the display substrate 102, and the first light-shielding layer 20 can be formed between the display substrate 102 and the third adhesive layer F3.

[0296] In this configuration, compared to disposing the first light-shielding layer 20 on the side of the transparent cover plate 10 close to the display substrate 102, the first light-shielding layer 20 can be positioned further away from the light-emitting surface of the foldable display panel 100. Furthermore, the adhesive layer (third adhesive layer F3) having an uneven surface after the first light-shielding layer 20 is attached can be positioned further away from the light-emitting surface of the foldable display panel 100 than the first adhesive layer F1.

[0297] Based on this, the distance between the first light-shielding layer 20 and the light-emitting surface S1 of the foldable display panel 100 can be increased, and the distance between the adhesive layer bonded to the first light-shielding layer 20 and the light-emitting surface S1 of the foldable display panel 100 can be increased. As a result, the adhesive layer (third adhesive layer F3) bonded to the first light-shielding layer 20 is farther away from the light-emitting surface S1 of the foldable display panel 100 than the first adhesive layer F1. The unevenness of the second adhesive layer F2 has a smaller impact on the PV value at the position of the light-transmitting area Q than the unevenness of the first adhesive layer F1. As a result, the PV value at the position of the light-transmitting area Q can be reduced to below 0.8λ, reducing the impact on the propagation direction of light at the position of the light-transmitting area Q, thereby improving the clarity of the photographic image and improving the quality of the foldable display panel 100.

[0298] In addition, compared with the first configuration, the unevenness of the third adhesive layer F3 in the second configuration has a smaller impact on the PV value at the light-transmitting area Q than the unevenness of the second adhesive layer F2.

[0299] Therefore, by setting the first light-shielding layer 20 on the side of the first buffer layer 40 close to the display substrate 102, the PV value at the position of the light-transmitting area Q can be reduced to below 0.8λ, thereby reducing the impact on the propagation direction of light at the position of the light-transmitting area Q, thereby improving the clarity of the photographic imaging and improving the quality of the foldable display panel 100.

[0300] The present disclosure does not specifically limit the above two methods. Both of the above methods can increase the distance between the first light-shielding layer 20 and the light-emitting surface S1 of the foldable display panel 100, while also increasing the distance between the adhesive layer bonded to the first light-shielding layer 20 and the light-emitting surface S1 of the foldable display panel 100. As a result, the adhesive layer (the second adhesive layer F2 or the third adhesive layer F3) bonded to the first light-shielding layer 20 is further away from the light-emitting surface S1 of the foldable display panel 100 than the first adhesive layer F1. The unevenness of the second adhesive layer F2 or the third adhesive layer F3 has a smaller impact on the PV value at the light-transmitting area Q than the unevenness of the first adhesive layer F1. As a result, the PV value at the light-transmitting area Q can be reduced to below 0.8λ, reducing the impact on the propagation direction of light at the light-transmitting area Q, thereby improving the clarity of photographic images and enhancing the quality of the foldable display panel 100.

[0301] In some embodiments, as shown in FIG8 , the first light shielding layer 20 may be an ink layer, and the thickness of the first light shielding layer 20 may be in the range of 2 μm to 5 μm.

[0302] The thickness range of the first light-shielding layer 20 in any of the above embodiments can be set as above. That is, since any of the above embodiments adopts the method of moving the first light-shielding layer 20 in the cover assembly 101 downward (toward the display substrate 102) to increase the distance between the first light-shielding layer 20 and the light-emitting surface of the foldable display panel 100, the effect of the adhesive layer after bonding with the first light-shielding layer 20 on the PV value at the position of the light-transmitting area Q is reduced, so that the PV value at the position of the light-transmitting area Q is reduced to below 0.8λ. The effect on the propagation direction of light at the position of the light-transmitting area Q can be reduced, thereby improving the clarity of the photographic image and improving the quality of the foldable display panel 100.

[0303] Based on this, the foldable display panel 100 provided by the embodiment of the present disclosure does not require the thickness of the first light-shielding layer 20 in the cover assembly 101 to be within the range of 2μm to 5μm, and there is no need to thin the first light-shielding layer 20, thereby meeting the requirements of the existing first light-shielding layer manufacturing process.

[0304] When the thickness of the first light-shielding layer 20 is equal to or close to 2 μm, the thickness of the first light-shielding layer 20 is relatively thin, which can not only meet the light-shielding degree requirement of the first light-shielding layer 20, but also meet the requirements of the existing manufacturing process; at the same time, it can reduce the influence of the first light-shielding layer 20 on the PV value at the position of the light-transmitting area Q, so as to improve the clarity of the imaging of the foldable display panel 100.

[0305] When the thickness of the first light-shielding layer 20 is equal to or close to 5 μm, the first light-shielding layer 20 is thicker, which can provide a better light-shielding effect for the first light-shielding layer 20, thereby preventing light leakage at the light-transmitting area Q. Furthermore, the thickness of the first light-shielding layer 20 is not too thick, which can reduce the impact on the PV value at the light-transmitting area Q to a certain extent, thereby improving the clarity of the images taken by the foldable display panel 100.

[0306] For example, the thickness of the first light shielding layer 20 is about 2 μm, 3 μm, 4 μm or 5 μm. However, the embodiment of the present disclosure is not limited thereto.

[0307] It should be noted that the first light shielding layer 20 is formed between the transparent cover plate 10 and the display substrate 102, and can also include two structures:

[0308] The first one is an improvement on the structure of the cover assembly 101 in the foldable display panel 100 . That is, the first light shielding layer 20 is disposed in the cover assembly 101 , and the first light shielding layer 20 belongs to the structure in the cover assembly 101 .

[0309] The second type is an improvement on the structure of the foldable display panel 100 . That is, the first light shielding layer 20 is provided between the cover assembly 101 and the display substrate 102 .

[0310] Figures 8 and 12 partially describe a first improvement to the structure of the cover assembly 101 in the foldable display panel 100. The structure of the cover assembly 101 will be further described below with reference to some related figures. Furthermore, a second improvement to the structure of the foldable display panel 100 will be described below with reference to other related figures.

[0311] In summary, in the embodiments provided herein, a first light-shielding layer 20 is provided that includes a first opening area K1, and the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 covers the orthographic projection of the first opening area K1 on the transparent cover plate 10. The first light-shielding layer 20 can be used to improve the problem of light leakage from the light-transmitting area Q of the foldable display panel 100. Furthermore, the first light-shielding layer 20 can be further moved toward the side closer to the display substrate 102, thereby moving it to the side of the transparent cover plate 10 closer to the display substrate 102. This can increase the distance between the first light-shielding layer 20 and the light-emitting surface S1 of the foldable display panel 100, and simultaneously increase the distance between the adhesive layer bonded to the first light-shielding layer 20 and the light-emitting surface S1 of the foldable display panel 100. As a result, the adhesive layer (second adhesive layer F2) bonded to the first light-shielding layer 20 is further away from the light-emitting surface S1 of the foldable display panel 100 than the first adhesive layer F1. The unevenness of the second adhesive layer F2 has a smaller impact on the PV value at the light-transmitting area Q than the unevenness of the first adhesive layer F1. Consequently, the PV value at the light-transmitting area Q can be reduced to below 0.8λ, reducing the impact on the propagation direction of light at the light-transmitting area Q, thereby improving the clarity of photographic images and enhancing the quality of the foldable display panel 100.

[0312] In some embodiments, referring to FIG. 8 , the third adhesive layer F3 may include a third opening area K3 , and the boundary of the orthographic projection of the third opening area K3 on the transparent cover 10 substantially overlaps with the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover.

[0313] Such a setting is equivalent to removing the third adhesive layer F3 at the position of the light-transmitting area Q, which can prevent the third adhesive layer F3 at the position of the light-transmitting area Q from affecting the bending of the foldable display panel 100. At the same time, it can also prevent the side of the third adhesive layer F3 away from the first buffer layer 40 from being contaminated, thereby improving the yield of the foldable display panel 100.

[0314] It should be noted that "substantially overlapping" can include absolute overlap and approximate overlap. That is, the floating range of the gap between the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 and the boundary of the orthographic projection of the third opening area K3 on the transparent cover plate 10 does not exceed the error threshold. Alternatively, the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 and the boundary of the orthographic projection of the third opening area K3 on the transparent cover plate 10 can be considered to relatively "overlap." The ratio of the error threshold to the length of the light-transmitting area Q can be within a range of 1% to 5%.

[0315] FIG13 is a structural diagram of a foldable display panel according to yet other embodiments.

[0316] In other embodiments, as shown in FIG. 13 , the first buffer layer 40 may further include a second opening area K2 , and the boundary of the orthographic projection of the second opening area K2 on the transparent cover 10 roughly overlaps with the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover.

[0317] Such a configuration is equivalent to removing the first buffer layer 40 at the position of the light-transmitting area Q, which can prevent the first buffer layer 40 at the position of the light-transmitting area Q from affecting the bending of the foldable display panel 100 and improve the bendability of the foldable display panel 100.

[0318] It should be noted that "substantially overlapping" can include absolute overlap and approximate overlap. That is, the floating range of the gap between the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 and the boundary of the orthographic projection of the second opening area K2 on the transparent cover plate 10 does not exceed the error threshold. Alternatively, the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 and the boundary of the orthographic projection of the second opening area K2 on the transparent cover plate 10 can be considered to relatively "overlap." The ratio of the error threshold to the length of the light-transmitting area Q can be within a range of 1% to 5%.

[0319] In some other embodiments, as shown in FIG13 , on the basis that the first buffer layer 40 may further include the second opening area K2, the second adhesive layer F2 between the first buffer layer 40 and the transparent cover plate 10 may include a fourth opening area K4. The boundary of the orthographic projection of the fourth opening area K4 on the transparent cover plate 10 substantially overlaps with the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover plate.

[0320] Such a setting is equivalent to removing the second adhesive layer F2 at the position of the light-transmitting area Q, which can prevent the second adhesive layer F2 at the position of the light-transmitting area Q from affecting the bending of the foldable display panel 100. At the same time, it can also prevent the side of the second adhesive layer F2 away from the first buffer layer 40 from being contaminated, thereby improving the yield of the foldable display panel 100.

[0321] It should be noted that "substantially overlapping" can include absolute overlap and approximate overlap. That is, the floating range of the gap between the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 and the boundary of the orthographic projection of the fourth opening area K4 on the transparent cover plate 10 does not exceed the error threshold. Alternatively, the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 and the boundary of the orthographic projection of the fourth opening area K4 on the transparent cover plate 10 can be considered to relatively "overlap." The ratio of the error threshold to the length of the light-transmitting area Q can be within a range of 1% to 5%.

[0322] FIG14 is a plan view of the first buffer layer in FIG6 .

[0323] In some embodiments, referring to FIG. 6 and FIG. 14 , the foldable display panel 100 further includes a bending zone ZZ located on one side of the display area AA.

[0324] The first buffer layer 40 includes a first side L1 and a second side L2 that are oppositely disposed. The first side L1 is located on the side of the second side L2 that is closer to the bending zone ZZ. The first side L1 includes a first line segment L11, a first arcuate transition segment G1, a second line segment L12, a second arcuate transition segment G2, and a third line segment L13 that are sequentially connected. The second line segment L12 protrudes toward the second side L2 and defines a groove structure U. The groove structure U is located within the bending zone.

[0325] As configured above, the first buffer layer 40 can form a groove structure U by utilizing the second line segment L12 to avoid the bending zone ZZ in the foldable display panel 100 and prevent affecting the configuration of the structure at the bending zone ZZ in the foldable display panel 100.

[0326] Furthermore, a first arcuate transition segment G1 and a second arcuate transition segment G2 are added to the first side L1 of the first buffer layer 40. The first arcuate transition segment G1 connects the first line segment L11 and the second line segment L12, and the second arcuate transition segment G2 connects the third line segment L13 and the second line segment L12.

[0327] Based on this, the first arc-shaped transition section G1 and the second arc-shaped transition section G2 in the first side L1 can be used to release bending stress and prevent the first buffer layer 40 from tearing at the bending zone ZZ position, thereby improving the quality of the foldable display panel 100.

[0328] In some examples, the bottom corner I of the groove structure U defined by the second line segment L12 protruding toward the second side L2 may be a rounded corner.

[0329] In this manner, the first buffer layer 40 utilizes a structure in which the first arc-shaped transition segment G1, the second line segment L12, and the second arc-shaped transition segment G2 are sequentially connected, so that the first arc-shaped transition segment G1 and one side wall of the groove structure U (the side wall connected to the first arc-shaped transition segment G1) form an "S"-shaped structure, and the second arc-shaped transition segment G2 and the other side wall of the groove structure U (the side wall connected to the second arc-shaped transition segment G2) form an "S"-shaped structure.

[0330] Based on this, the first arc-shaped transition section G1 and the second arc-shaped transition section G2 in the first side edge L1 and the two bottom corners I (rounded corners) in the groove structure U can be used to release bending stress to prevent the first buffer layer 40 from tearing at the bending zone ZZ position, thereby improving the quality of the foldable display panel 100.

[0331] In some examples, when the bottom angle I of the groove structure U is rounded, the radius thereof ranges from 0.2 mm to 1 mm.

[0332] When the radius of the bottom angle of the groove structure U satisfies the range of 0.2mm to 1mm, the bottom angle of the groove structure U can be made arc-shaped, which can be used to release bending stress and prevent the first buffer layer 40 from tearing at the bending zone ZZ position, thereby improving the quality of the foldable display panel 100.

[0333] Illustratively, the radius of the bottom angle of the groove structure U is approximately any one of 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1 mm.

[0334] It should be noted that the radius of the bottom angle of the groove structure U is approximately 0.5 mm. Due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the radius of the bottom angle of the groove structure U fluctuates within the range of 10% × 0.5 mm, it can also be considered that the radius of the bottom angle of the groove structure U satisfies and is equal to 0.5 mm.

[0335] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the radius of the bottom angle of the groove structure U fluctuates within the range of 5%×0.5mm, it can also be considered that the radius of the bottom angle of the groove structure U satisfies and is equal to 0.5mm.

[0336] FIG. 15 is a diagram illustrating a film layer structure of a foldable display panel according to some embodiments.

[0337] Considering the subsequent demand for improved specifications for small ball drop tests, the small ball drop specification must be met to be more than 2cm (the judgment standard is that the screen can display normally).

[0338] Based on this, in some embodiments, as shown in FIG15 , the foldable display panel 100 further includes a second buffer layer 50. The second buffer layer 50 is located on the side of the first buffer layer 40 that is closer to the transparent cover plate 10. The second buffer layer 50 is disposed between the first buffer layer 40 and the transparent cover plate 10. The material of the second buffer layer 50 can be different from that of the first buffer layer 40, and the elastic modulus of the second buffer layer 50 can be less than or equal to that of the first buffer layer 40.

[0339] As shown in the above structure, the foldable display panel 100 can increase the hardness and rebound force within the foldable display panel 100 by adding a second buffer layer 50. During a small ball drop test, the second buffer layer 50 is generally impacted first. After the impact, the second buffer layer 50 deforms and absorbs the stress, protecting the first buffer layer 40 and reducing the deformation of the first buffer layer 40. In this way, the deformation transmitted by the first buffer layer 40 to the display substrate 102 is small, reducing the deformation of the display substrate 102, thereby increasing the strength of the cover assembly 101 and reducing the possibility of damage to the cover assembly 101. At the same time, the second buffer layer 50 has greater elasticity and can be used to further disperse the impact stress, improving problems such as breakage and chipping of the transparent cover 100 during the small ball drop test, thereby improving the quality of the foldable display panel 100.

[0340] In some examples, referring to FIG. 15 , the elastic modulus of the second buffer layer 50 may be in the range of 5 MPa to 100 MPa.

[0341] When the elastic modulus of the second buffer layer 50 is equal to or close to 5 MPa, the elastic modulus of the second buffer layer 50 is relatively low, which is beneficial for improving the bending performance of the foldable display panel 100. In addition, the second buffer layer 50 can meet the requirements for resistance and resilience, thereby protecting the transparent cover plate 10 and preventing the transparent cover plate 10 from breaking when the foldable display panel 100 is impacted by external forces.

[0342] When the elastic modulus of the second buffer layer 50 is equal to or close to 100 MPa, the elastic modulus of the second buffer layer 50 is relatively large, which can provide the second buffer layer with excellent resistance and resilience, preventing the transparent cover 10 from cracking. In addition, the second buffer layer 50 can meet the bendability requirements of the foldable display panel 100.

[0343] In some examples, the elastic modulus of the second buffer layer 50 may be in the range of 20 MPa to 80 MPa.

[0344] When the elastic modulus of the second buffer layer 50 is within the range of 20 MPa to 80 MPa, the second buffer layer 50 can meet the requirements of the foldable display panel 100 for bendability, as well as the requirements for impact resistance and resilience, thereby protecting the transparent cover 10 .

[0345] Illustratively, the elastic modulus of the second buffer layer 50 is approximately any one of 5 MPa, 10 MPa, 20 MPa, 30 MPa, 40 MPa, 50 MPa, 60 MPa, 70 MPa, 80 MPa, 90 MPa or 100 MPa.

[0346] Taking the elastic modulus of the second buffer layer 50 of approximately 50 MPa as an example, the second buffer layer 50 can have good resistance and resilience, preventing the transparent cover 10 from breaking, and meeting the bendability requirements of the foldable display panel 100.

[0347] It should be noted that due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the elastic modulus error floating range of the second buffer layer 50 fluctuates within the range of 10%×50Mpa, it can also be considered that the elastic modulus of the second buffer layer 50 is equal to 50Mpa.

[0348] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the elastic modulus error floating range of the second buffer layer 50 fluctuates within the range of 5%×50Mpa, it can also be considered that the elastic modulus of the second buffer layer 50 is equal to 50Mpa.

[0349] In some examples, referring to FIG. 15 , the material of the second buffer layer 50 may be thermoplastic polyurethane (TPU).

[0350] A thermoplastic polyurethane elastomer (TPU) is formed on the side of the transparent cover plate 10 close to the display substrate 102. The thermoplastic polyurethane elastomer (TPU) has good elasticity and can be used to further disperse impact stress to protect the transparent cover plate 10 and prevent the transparent cover plate 10 from breaking when the foldable display panel 100 is impacted by external force.

[0351] In some examples, the thickness of the second buffer layer 50 ranges from 50 μm to 200 μm.

[0352] When the thickness of the second buffer layer 50 is equal to or close to 50 μm, the second buffer layer 50 can be made thinner. The second buffer layer 50 can provide better resistance and resilience for the cover assembly 101. The second buffer layer 50 can further disperse the impact stress, thereby protecting the transparent cover 10 and preventing the transparent cover 10 from breaking when the foldable display panel 100 is impacted by external forces. In addition, it can also help to make the foldable display panel 100 lighter and thinner.

[0353] When the thickness of the second buffer layer 50 is equal to or close to 200 μm, the second buffer layer 50 can be thicker. The second buffer layer 50 can make the cover assembly 101 more flexible, thereby meeting the bendability requirements of the foldable display panel 100. In addition, the cover assembly 101 can also have good resistance and resilience, and the second buffer layer 50 can be used to further disperse impact stress, thereby protecting the transparent cover 10 and preventing the transparent cover 10 from breaking when the foldable display panel 100 is impacted by external forces.

[0354] In some other examples, the thickness of the second buffer layer 50 ranges from 80 μm to 120 μm.

[0355] When the thickness of the second buffer layer 50 is equal to or close to 80 μm, the second buffer layer 50 can provide better resistance and resilience for the cover assembly 101, so as to utilize the second buffer layer 50 to further disperse the impact stress, thereby protecting the transparent cover 10 and preventing the transparent cover 10 from breaking when the foldable display panel 100 is impacted by external force.

[0356] When the thickness of the second buffer layer 50 is equal to or close to 120 μm, the second buffer layer 50 can make the cover assembly 101 more flexible, thereby meeting the bendability requirements of the foldable display panel 100. In addition, the cover assembly 101 can also have good resistance and resilience, preventing the transparent cover 10 from cracking.

[0357] Illustratively, the thickness of the second buffer layer 50 is approximately 80 μm, 90 μm, 100 μm, 110 μm, or 120 μm.

[0358] Taking the thickness of the second buffer layer 50 as an example, which is approximately 100 μm, the second buffer layer 50 can not only make the cover assembly 101 have better flexibility to meet the bendability requirements of the foldable display panel 100; it can also make the cover assembly 101 have better resistance and resilience, so that the second buffer layer 50 can be used to further disperse the impact stress to protect the transparent cover 10 and prevent the transparent cover 10 from breaking when the foldable display panel 100 is impacted by external force.

[0359] It should be noted that the thickness of the second buffer layer 50 is approximately 100 μm. Due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the thickness of the second buffer layer 50 fluctuates within the range of 10%×100 μm, it can also be considered that the thickness of the second buffer layer 50 satisfies the requirement of being equal to 100 μm.

[0360] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the thickness of the second buffer layer 50 fluctuates within the range of 5%×100μm, it can also be considered that the thickness of the second buffer layer 50 satisfies the requirement of being equal to 100μm.

[0361] In some embodiments, please continue to refer to FIG. 17 , when a second buffer layer 50 is added to the cover assembly 101 , the thickness of the transparent cover 10 will be increased to a certain extent, and the resistance and resilience of the cover assembly 101 can also be improved simultaneously.

[0362] Based on this, the transparent cover plate 10 can be thinned. That is, the thickness of the transparent cover plate 10 can be set to about 40 μm, which is about 10 μm thinner than the transparent cover plate 10 with a thickness of 50 μm.

[0363] In this way, by thinning the transparent cover 10, it is beneficial to reduce the thickness of the cover assembly 101 and reduce the hardness of the cover assembly 101, so that the cover assembly 101 can better meet the bendability requirements of the foldable display panel 100.

[0364] For example, when a second buffer layer 50 is added to the cover assembly 101 and the transparent cover 10 is thinned, the thickness of the cover assembly 101 will still increase to a certain extent. For example, the thickness of the cover assembly 101 will increase by more than 100 μm relative to the thickness of the cover assembly 101 shown in Figure 9. However, such a setting can also simultaneously increase the resistance and resilience of the cover assembly 101. For example, the resistance and resilience of the cover assembly 101 are increased by 2.14% relative to the resistance and resilience of the cover assembly 101 shown in Figure 9, which can meet the requirements of the hinge design of the subsequent foldable display panel 100.

[0365] In some embodiments, referring to FIG. 17 , the cover assembly 101 may further include a fourth adhesive layer F4, which is located between the second buffer layer 50 and the first buffer layer 40. The fourth adhesive layer F4 can securely connect the second buffer layer 50 and the first buffer layer 40 to improve the stability of the cover assembly 101, thereby increasing the good frequency of the foldable display panel 100.

[0366] In some examples, the fourth adhesive layer F4 can be made of optically clear adhesive (OCA). Because OCA has a certain degree of viscosity, it can securely connect the second buffer layer 50 and the first buffer layer 40, improving the stability of the cover assembly 101. Furthermore, because OCA is relatively soft and elastic, it can effectively absorb some bending stress and provide a certain degree of protection for the transparent cover 10, preventing it from breaking when the foldable display panel 100 is subjected to external impact.

[0367] In addition, the thickness and shrinkage of the fourth adhesive layer F4 may be similar to those of the first adhesive layer F1 , and reference may be made to the description of the first adhesive layer F1 in the above embodiment, which will not be repeated here.

[0368] FIG16 is a diagram illustrating a film layer structure of a foldable display panel according to some other embodiments, and FIG17 is a diagram illustrating a film layer structure of a foldable display panel according to some other embodiments.

[0369] In some embodiments, referring to FIG. 15 to FIG. 17 , when the second buffer layer 50 is added to the cover assembly 101 , the location of the first light shielding layer 20 may include the following three situations:

[0370] The first method: Referring to FIG15 , the first light shielding layer 20 is disposed between the first light shielding layer 20 and the second buffer layer 50. This method is similar to the structure shown in FIG8 , which is equivalent to disposing the first light shielding layer 20 between the transparent cover 10 and the second adhesive layer F2.

[0371] This arrangement allows the first light-shielding layer 20 to be positioned further away from the light-emitting surface of the foldable display panel 100 than if the first light-shielding layer 20 were positioned on the side of the transparent cover plate 10 closer to the display substrate 102. Furthermore, the adhesive layer (second adhesive layer F2) having an uneven surface after the first light-shielding layer 20 is attached can be positioned further away from the light-emitting surface of the foldable display panel 100 than the first adhesive layer F1.

[0372] Based on this, the distance between the first light-shielding layer 20 and the light-emitting surface S1 of the foldable display panel 100 can be increased, and the distance between the adhesive layer bonded to the first light-shielding layer 20 and the light-emitting surface S1 of the foldable display panel 100 can be increased. As a result, the adhesive layer (second adhesive layer F2) bonded to the first light-shielding layer 20 is farther away from the light-emitting surface S1 of the foldable display panel 100 than the first adhesive layer F1. The unevenness of the second adhesive layer F2 has a smaller impact on the PV value at the position of the light-transmitting area Q than the unevenness of the first adhesive layer F1. As a result, the PV value at the position of the light-transmitting area Q can be reduced to below 0.8λ, reducing the impact on the propagation direction of light at the position of the light-transmitting area Q, thereby improving the clarity of the photographic image and improving the quality of the foldable display panel 100.

[0373] The second type: as shown in FIG. 16 , the first light shielding layer 20 is disposed between the second buffer layer 50 and the first buffer layer 40 .

[0374] Such an arrangement can further increase the distance between the first light-shielding layer 20 and the light-emitting surface of the foldable display panel 100 compared to disposing the first light-shielding layer 20 on the side of the transparent cover 10 close to the display substrate 102. Furthermore, the adhesive layer (fourth adhesive layer F4) with an uneven surface after the first light-shielding layer 20 is attached can be further away from the light-emitting surface of the foldable display panel 100 than the first adhesive layer F1.

[0375] Based on this, the first light-shielding layer 20 is further moved downward (toward the display substrate 102) to the side of the second buffer layer 50 closer to the display substrate 102. This can increase the distance between the first light-shielding layer 20 and the light-emitting surface of the foldable display panel 100, while also increasing the distance between the adhesive layer bonded to the first light-shielding layer 20 and the light-emitting surface S1 of the foldable display panel 100. As a result, the adhesive layer (fourth adhesive layer F4) bonded to the first light-shielding layer 20 is further away from the light-emitting surface S1 of the foldable display panel 100 than the first adhesive layer F1. The unevenness of the fourth adhesive layer F4 has a smaller impact on the PV value at the position of the light-transmitting area Q than the unevenness of the first adhesive layer F1.

[0376] Moreover, the adhesive layer (fourth adhesive layer F4) bonded to the first light-shielding layer 20 is also farther away from the light-emitting surface S1 of the foldable display panel 100 relative to the second adhesive layer F2. The unevenness of the fourth adhesive layer F4 has a smaller impact on the PV value at the position of the light-transmitting area Q than the unevenness of the second adhesive layer F2.

[0377] Therefore, by setting the first light-shielding layer 20 on the side of the first buffer layer 40 close to the display substrate 102, the PV value at the position of the light-transmitting area Q can be reduced to below 0.8λ, thereby reducing the impact on the propagation direction of light at the position of the light-transmitting area Q, thereby improving the clarity of the photographic imaging and improving the quality of the foldable display panel 100.

[0378] The third type: as shown in FIG17 , the first light shielding layer 20 is located on the side of the first buffer layer 40 close to the display substrate 102 . That is, the first light shielding layer 20 is disposed between the first buffer layer 40 and the display substrate 102 .

[0379] Such an arrangement can further increase the distance between the first light-shielding layer 20 and the light-emitting surface of the foldable display panel 100, compared to disposing the first light-shielding layer 20 on the side of the transparent cover 10 close to the display substrate 102, or compared to disposing the first light-shielding layer 20 on the side of the second buffer layer 50 close to the display substrate 102. Furthermore, the adhesive layer (third adhesive layer F3) having an uneven surface after the first light-shielding layer 20 is attached can be further away from the light-emitting surface of the foldable display panel 100 than the first adhesive layer F1.

[0380] Based on this, the first light-shielding layer 20 is further moved downward (toward the display substrate 102) to the side of the first buffer layer 40 closer to the display substrate 102. This can increase the distance between the first light-shielding layer 20 and the light-emitting surface of the foldable display panel 100, while also increasing the distance between the adhesive layer bonded to the first light-shielding layer 20 and the light-emitting surface S1 of the foldable display panel 100. As a result, the adhesive layer (third adhesive layer F3) bonded to the first light-shielding layer 20 is further away from the light-emitting surface S1 of the foldable display panel 100 than the first adhesive layer F1. The unevenness of the third adhesive layer F3 has a smaller impact on the PV value at the position of the light-transmitting area Q than the unevenness of the first adhesive layer F1.

[0381] Moreover, the adhesive layer (third adhesive layer F3) bonded to the first light-shielding layer 20 is also farther away from the light-emitting surface S1 of the foldable display panel 100 than the second adhesive layer F2 and the fourth adhesive layer F4. The unevenness of the third adhesive layer F3 has a smaller impact on the PV value at the position of the light-transmitting area Q than the unevenness of the second adhesive layer F2 and the fourth adhesive layer F4.

[0382] Therefore, by setting the first light-shielding layer 20 on the side of the first buffer layer 40 close to the display substrate 102, the PV value at the position of the light-transmitting area Q can be reduced to below 0.8λ, thereby reducing the impact on the propagation direction of light at the position of the light-transmitting area Q, thereby improving the clarity of the photographic imaging and improving the quality of the foldable display panel 100.

[0383] In some embodiments, when the foldable display panel 100 includes a second buffer layer 50, the second buffer layer 50 also needs to avoid the bending zone. That is, the second buffer layer 50 can have a substantially similar structure to the first buffer layer 40. Specifically, the second buffer layer 50 and the first side L1 of the first buffer layer 40 are also designed with a corresponding "S" shape to release bending stress and prevent tearing of the second buffer layer 50.

[0384] In other examples, the cover assembly 101 may further include an auxiliary transparent cover, which may be located between the transparent cover 10 and the first buffer layer 40. When the cover assembly 101 includes the second buffer layer 50, the auxiliary transparent cover may be located between the transparent cover 10 and the second buffer layer 50.

[0385] An auxiliary transparent cover is added to the cover assembly 101 to increase the hardness of the cover assembly 101 so that the transparent cover 10 can achieve the effect of long-term protection of the display substrate 102; and the auxiliary transparent cover can also be used to support and protect the transparent cover 10.

[0386] In some examples, the auxiliary transparent cover plate can be made of ultra-thin glass (UTG). Ultra-thin glass can further increase the hardness of the cover plate assembly 101 while meeting the bendability requirements of the foldable display panel 100. Furthermore, ultra-thin glass can have higher clarity, thereby improving the quality of images taken by the foldable display panel 100.

[0387] In addition, for parameters such as the thickness and elastic modulus of the auxiliary transparent cover plate, reference may be made to the description of the transparent cover plate 10 in the above embodiment, which will not be repeated here.

[0388] The above mainly discusses adjusting the position of the first light-shielding layer 20 in the cover assembly 101 to improve the clarity of images taken with the foldable display panel 100 and thereby enhance the quality of the foldable display panel 100. The following, combined with the accompanying drawings, describes another approach to improving the clarity of images taken with the foldable display panel 100 and thereby enhance the quality of the foldable display panel 100.

[0389] FIG. 18 is another structural diagram of a foldable display panel according to some embodiments, and FIG. 19 is another structural diagram of a foldable display panel according to some embodiments.

[0390] In some embodiments, as shown in conjunction with Figures 18 and 19 , the foldable display panel 100 may further include an encapsulation layer 60, which is located on a side of the display substrate 102 adjacent to the cover assembly 101. The encapsulation layer 60 can be used to isolate moisture, preventing it from entering the display substrate 102 and causing failure of the devices (light-emitting devices O) therein, thereby increasing the lifespan of the foldable display panel 100.

[0391] In some examples, the encapsulation layer 60 includes a first inorganic encapsulation layer 61, an organic encapsulation layer 62, and a second inorganic encapsulation layer 63. The organic encapsulation layer 62 is located between the first and second inorganic encapsulation layers 61 and 62, and the first inorganic encapsulation layer 61 is closer to the display substrate 102 than the organic encapsulation layer 62.

[0392] In addition, the encapsulation layer 60 can also include more inorganic encapsulation layers and organic encapsulation layers, but generally speaking, it is necessary to ensure that the top layer in the encapsulation layer 60 (the layer farthest from the display substrate 102 in the encapsulation layer 60) is an inorganic encapsulation layer to effectively block water and oxygen.

[0393] In some examples, the material of the first inorganic encapsulation layer 61 may be SiON (silicon oxynitride), and the material of the second inorganic encapsulation layer 63 may be SiN (silicon nitride). In other examples, the material of the first inorganic encapsulation layer 61 may also be the same as the material of the second inorganic encapsulation layer 63.

[0394] In some examples, the first inorganic encapsulation layer 61 and the second inorganic encapsulation layer 63 may be formed by deposition.

[0395] In some examples, the organic encapsulation layer 62 may be made of an organic material suitable for inkjet printing. The organic encapsulation layer 62 may be formed by inkjet printing.

[0396] 18 and 19 , the foldable display panel 100 may further include a color filter structure layer 70 . The color filter structure layer 70 is located on a side of the encapsulation layer 60 close to the transparent cover 10 .

[0397] The color filter structure layer 70 includes a black matrix layer 71 and color filter units (not shown). The black matrix layer (BM) 71 includes a plurality of second opening regions (not shown) spaced apart and extending through the black matrix layer 71. The color filter units are located within the second opening regions.

[0398] As shown above, the foldable display panel 100 utilizes COE (Color Film On Encapsulation) technology, which utilizes a color film directly on the encapsulation layer. COE technology replaces external polarizers with color films, saving significant production costs and offering greater production benefits. Furthermore, the foldable display panel 100 utilizing COE technology can achieve higher light extraction efficiency and improved bending resistance, meeting product performance requirements.

[0399] Based on the above COE structure, the first light shielding layer 20 and the black matrix layer 71 can be provided on the same layer. The first light shielding layer 20 and the black matrix layer 71 can be formed by the same patterning process.

[0400] With this arrangement, on the one hand, the first light-shielding layer 20 does not need to be made separately, which can help simplify the process of the foldable display panel 100. On the other hand, arranging the first light-shielding layer 20 and the black matrix layer 71 in the same layer is equivalent to arranging the first light-shielding layer 20 on the outside of the cover assembly 101, which can better improve the influence of the adhesive layer after the first light-shielding layer 20 is bonded on the PV value at the position of the light-transmitting area Q. In addition, since the first light-shielding layer 20 and the black matrix layer 71 are arranged in an entire layer, the flatness of the film layer in the light-transmitting area Q of the foldable display panel 100 can also be reduced. Based on this, the PV value at the position of the light-transmitting area Q can be reduced to below 0.8λ, or even to below 0.4λ. The influence of the first light-shielding layer 20 on the propagation direction of light at the position of the light-transmitting area Q can be further reduced, thereby improving the clarity of the photographic imaging and improving the quality of the foldable display panel 100.

[0401] In some examples, the first light shielding layer 20 and the black matrix layer 71 may be provided on the same layer, that is, the first light shielding layer 20 and the black matrix layer 71 may be formed by the same patterning process.

[0402] Based on this, the thickness of the first light shielding layer 20 is equal to the thickness of the black matrix layer 71 , and the thickness of the first light shielding layer 20 ranges from 1 μm to 1.6 μm.

[0403] Table 1 shows the variation of optical density of the first light-shielding layer with its thickness.

[0404] From Table 1 above, it can be seen that when the thickness of the first light-shielding layer 20 is equal to or close to 1 μm, the thickness of the first light-shielding layer 20 is relatively thin, but at this time the OD value of the first light-shielding layer 20 can reach above 2.5, which can meet the light-shielding degree requirement of the first light-shielding layer 20. At the same time, the thickness of the first light-shielding layer 20 is relatively thin, which can be beneficial to saving resources and realizing the lightweight and thinness of the foldable display panel 100.

[0405] When the thickness of the first light-shielding layer 20 is equal to or close to 1.6 μm, the thickness of the first light-shielding layer 20 is relatively thick. In this case, the OD value of the first light-shielding layer 20 can reach 4.2, which can make the first light-shielding layer 20 have a better light-shielding effect, thereby preventing light leakage at the light-transmitting area Q of the foldable display panel 100. In addition, the first light-shielding layer 20 will not be too thick, which will waste resources.

[0406] In some examples, the thickness of the first light shielding layer 20 is equal to the thickness of the black matrix layer 71 , and the thickness of the first light shielding layer 20 ranges from 1 μm to 1.4 μm.

[0407] When the thickness of the first light-shielding layer 20 is equal to or close to 1 μm, it can meet the light-shielding degree requirement of the first light-shielding layer 20 while being beneficial to saving resources and achieving a lightweight and thin foldable display panel 100 .

[0408] When the thickness of the first light shielding layer 20 is equal to or close to 1.6 μm, the first light shielding layer 20 can have a better light shielding effect to prevent light leakage at the light-transmitting area Q of the foldable display panel 100. In addition, the first light shielding layer 20 will not be too thick and waste resources.

[0409] For example, the thickness of the first light shielding layer 20 is about 1.0 μm, 1.1 μm, 1.2 μm, 1.3 μm or 1.4 μm. However, the embodiment of the present disclosure is not limited thereto.

[0410] For example, a first light-shielding layer 20 having a thickness of approximately 1.2 μm is used. When the thickness of the first light-shielding layer 20 is approximately 1.2 μm, the OD value of the first light-shielding layer 20 can reach 3.25. This means that the first light-shielding layer 20 can have a higher optical density, resulting in a better light-shielding effect. This effectively blocks light from the light-transmitting region Q of the foldable display panel 100, thereby preventing light leakage from the light-transmitting region Q of the foldable display panel 100.

[0411] It should be noted that due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the thickness of the first shading layer 20 fluctuates within the range of 10%×1.2μm, it can also be considered that the thickness of the first shading layer 20 satisfies and is equal to 1.2μm.

[0412] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the thickness of the first shading layer 20 fluctuates within the range of 5%×1.2μm, it can also be considered that the thickness of the first shading layer 20 satisfies the requirement of being equal to 1.2μm.

[0413] In summary, when the first light-shielding layer 20 is provided on the same layer as the black matrix layer 71, the thickness of the first light-shielding layer 20 can be approximately 1.3 μm, or even as low as 1 μm. Compared to the ink layer in the cover assembly 101, the first light-shielding layer 20 provided on the same layer as the black matrix layer 71 is thinner, and the light-shielding effect also meets the requirements. Based on this, the influence of the first light-shielding layer 20 on the propagation direction of light at the position of the light-transmitting area Q is further reduced, thereby improving the clarity of the photographic image and enhancing the quality of the foldable display panel 100.

[0414] In some embodiments, referring to FIG18 , the first light shielding layer 20 and the black matrix layer 71 are disconnected, so that a gap J exists between the first light shielding layer 20 and the black matrix layer 71. Thus, rainbow pattern detection can be performed at the gap J between the light shielding layer 20 and the black matrix layer 71.

[0415] In other embodiments, in order to improve the effect of the first light-shielding layer 20 on the PV value at the light-transmitting area Q, the first light-shielding layer 20 is moved down to the same layer as the black matrix layer 71. That is, no other light-shielding layer is provided on the side of the black matrix layer 71 (first light-shielding layer 20) away from the display substrate 102 to prevent the PV value at the light-transmitting area Q from being affected.

[0416] If a gap J is provided between the first light-shielding layer 20 and the black matrix layer 71 (as shown in FIG18 ), some light will be emitted from the foldable display panel 100 through the gap J, thereby causing light leakage and affecting the quality of the foldable display panel 100 .

[0417] Based on this, referring to FIG19 , the first light shielding layer 20 can be connected to the black matrix layer 71. It can be understood that when the black matrix layer 71 is formed, it can be extended to the edge of the light-transmitting area Q so that the black matrix layer 71 in the area around the light-transmitting area Q can be reused as the light shielding layer 20.

[0418] With such a configuration, the black matrix layer 71 can be used to effectively block light, thereby preventing the foldable display panel 100 from leaking light, thereby improving the quality of the foldable display panel 100 .

[0419] It should be noted that the embodiment of the present disclosure does not specifically limit the positional relationship between the two black matrix layers 71 and the first light shielding layer 20 , and can be adjusted in a specific manner.

[0420] In some embodiments, please refer to Figures 18 and 19. Since the first light-shielding layer 20 is on the same layer as the black matrix layer 71, the first light-shielding layer 20 needs to include a first opening area K1, and the boundary of the positive projection of the light-transmitting area Q on the transparent cover 10 roughly coincides with the boundary of the positive projection of the first opening area K1 on the transparent cover 10.

[0421] Based on this, the light at the edge of the opening area Q can be blocked to improve the problem of light leakage in the opening area Q; and the first light-shielding layer 20 can be prevented from affecting the transmittance at the position of the light-transmitting area Q, so as to improve the quality of the foldable display panel 100.

[0422] It should be noted that "substantially overlapping" can include absolute overlap and approximate overlap. That is, the floating range of the gap between the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 and the boundary of the orthographic projection of the first opening area K1 on the transparent cover plate 10 does not exceed the error threshold. Alternatively, the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 and the boundary of the orthographic projection of the first opening area K1 on the transparent cover plate 10 can be considered to relatively "overlap." The ratio of the error threshold to the length of the light-transmitting area Q can be within a range of 1% to 5%.

[0423] In some examples, the black matrix layer 71 is provided as a whole layer when it is formed. Subsequently, when the light-transmitting area Q of the foldable display panel 100 is cut, the black matrix layer 71 within the light-transmitting area Q can be removed to form the first opening area K1. Furthermore, the first light-shielding layer 20 can include the first opening area K1, and the boundary of the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 substantially coincides with the boundary of the orthographic projection of the first opening area K1 on the transparent cover plate 10.

[0424] In some embodiments, referring to Figures 18 and 19 , the foldable display panel 100 further includes an overcoating (OC) 80, which is located on the side of the black matrix layer 71 away from the encapsulation layer 60. The overcoating 80 is used to cover the color filter structure layer 70. On the one hand, the overcoating 80 can protect the color filter structure layer 70, and on the other hand, the overcoating 80 can also play a flattening role. When the foldable display panel 100 is subsequently formed, the side of the overcoating 80 away from the color filter structure layer 70 can be attached to the cover assembly 101.

[0425] In some embodiments, as shown in conjunction with FIG. 18 and FIG. 19 , the foldable display panel 100 further includes an isolation dam R. The isolation dam R is co-layered with the encapsulation layer 60 and surrounds at least a portion of the encapsulation layer 60. Thus, the isolation dam R can both restrict the encapsulation layer 60 and prevent it from flowing. The isolation dam R can also improve the encapsulation capability of the light-transmitting area Q of the foldable display panel 100, helping to isolate it from moisture erosion.

[0426] The “isolation dam R is provided around at least a portion of the encapsulation layer 60 ” includes the following two situations:

[0427] The first type: the isolation dam R may be a closed-loop structure, and the isolation dam R is disposed around the encapsulation layer 60 .

[0428] The second type: the isolation dam R may also be a non-closed-loop structure, and the isolation dam R is provided around a portion of the encapsulation layer 60 .

[0429] The present disclosure does not specifically limit the above two situations. Both situations can utilize the isolation dam R to improve the encapsulation capability of the light-transmitting area Q of the foldable display panel 100, thereby helping to isolate it from water vapor erosion. The following describes the first situation, in which the isolation dam R can be a closed-loop structure and is disposed around the encapsulation layer 60.

[0430] In some embodiments, referring to Figures 18 and 19 , the foldable display panel 100 further includes a peripheral region FQ surrounding the light-transmitting region Q. The foldable display panel 100 further includes a plurality of first spacer columns C1, which are located between the first light-shielding layer 20 and the encapsulation layer 60. The plurality of first spacer columns C1 are located within the peripheral region FQ and are radially spaced apart along the light-transmitting region Q.

[0431] With such a configuration, the plurality of first spacer columns C1 can be used to improve the packaging capability of the light-transmitting area Q of the foldable display panel 100 , thereby helping to isolate the light-transmitting area Q from being corroded by water vapor.

[0432] 18 and 19 illustrate an example in which seven first isolation columns C1 are provided in the peripheral region FQ. However, the number of the first isolation columns C1 in the embodiment of the present disclosure is not limited thereto.

[0433] In some embodiments, referring to FIG. 18 and FIG. 19 , the foldable display panel 100 further includes a plurality of second spacer columns C2. The plurality of second spacer columns C2 are located between the black matrix layer 71 and the encapsulation layer 60. The plurality of second spacer columns C2 are located within the peripheral region FQ and radially spaced along the light-transmitting region Q. The second spacer columns C2 are closer to the display area AA than the first spacer columns C1.

[0434] With such a configuration, the plurality of second spacer columns C2 can be used to improve the packaging capability of the light-transmitting area Q of the foldable display panel 100 , thereby helping to isolate the light-transmitting area Q from being corroded by water vapor.

[0435] 18 and 19 illustrate an example in which four second isolation columns C2 are provided in the peripheral region FQ. However, the number of the second isolation columns C2 in the embodiment of the present disclosure is not limited thereto.

[0436] 18 and 19 , the display substrate 102 in the foldable display panel 100 further includes: a substrate 00 and a padding layer 90 located on the substrate 00 . The padding layer 90 includes a first padding layer 91 and a second padding layer 92 .

[0437] In some examples, the substrate 00 may be a flexible substrate. For example, the material of the substrate 00 may be an organic material. For example, the material of the substrate 00 may be any one of polyimide (PI), polycarbonate (PC), or polyvinyl chloride (PVC).

[0438] In some examples, the first liner layer 91 includes multiple first liners 911, and the multiple first liners 911 can correspond one-to-one to the first isolation column C1, and the orthographic projection of the first liners 911 on the substrate 00 at least partially overlaps with the orthographic projection of the first isolation column C1 on the substrate 00.

[0439] Based on this, the first spacer 911 can be used to increase the height of the first isolation column C1, so that the first isolation column C1 can better improve the packaging capability of the light-transmitting area Q of the foldable display panel 100 and help isolate it from water vapor erosion.

[0440] The orthographic projection of the first liner 911 on the substrate 00 at least partially overlaps with the orthographic projection of the first isolation column C1 on the substrate 00 , which may include the following three situations:

[0441] The first type: the orthographic projection of the first liner 911 on the substrate 00 at least partially overlaps with the orthographic projection of the first isolation column C1 on the substrate 00 .

[0442] The second type: the orthographic projection of the first liner 911 on the substrate 00 covers the orthographic projection of the first isolation column C1 on the substrate 00 .

[0443] The third type is that the boundary of the orthographic projection of the first liner 911 on the substrate 00 substantially overlaps with the boundary of the orthographic projection of the first isolation column C1 on the substrate 00 .

[0444] In the three methods described above, the first spacer 911 can be used to increase the height of the first isolation column C1, which helps to isolate the erosion of water vapor. Among them, since Figures 18 and 19 mainly introduce the positions of the first light-shielding layer 20 and the black matrix layer 71, Figures 18 and 19 do not illustrate the details of the surface of each film layer. For example, it is not directly illustrated that the first spacer 911 causes the film layer below the first isolation column C1 to bulge. However, in an actual foldable display panel, the film layer below the first isolation column C1 should be supported by the first spacer 911 to form a bulge.

[0445] In some examples, the second liner layer 92 includes multiple second liners 921, which can correspond one-to-one to the second isolation column C2, and the positive projection of the second liner 921 on the substrate 00 at least partially overlaps with the positive projection of the second isolation column C2 on the substrate 00.

[0446] Based on this, the second liner 921 can be used to increase the height of the second isolation column C2, so that the second isolation column C2 can better improve the packaging capability of the light-transmitting area Q of the foldable display panel 100, and help isolate it from water vapor erosion.

[0447] The orthographic projection of the second liner 921 on the substrate 00 at least partially overlaps with the orthographic projection of the second isolation column C2 on the substrate 00, which may include the following three situations:

[0448] The first type: the orthographic projection of the second liner 921 on the substrate 00 partially overlaps with the orthographic projection of the second isolation column C2 on the substrate 00 .

[0449] The second type: the boundary of the orthographic projection of the second liner 921 on the substrate 00 roughly overlaps with the boundary of the orthographic projection of the second isolation column C2 on the substrate 00 .

[0450] The third type: the orthographic projection of the second liner 921 on the substrate 00 covers the orthographic projection of the second isolation column C2 on the substrate 00 .

[0451] In the three methods described above, the second spacer 921 can be used to increase the height of the second isolation column C2, which helps to isolate the erosion of water vapor. Among them, since Figures 18 and 19 mainly introduce the positions of the first light shielding layer 20 and the black matrix layer 71, Figures 18 and 19 do not illustrate the details of the surface of each film layer. For example, it is not directly illustrated that the second spacer 921 causes the film layer below the second isolation column C2 to bulge. However, in an actual foldable display panel, the film layer below the first isolation column C1 should be supported by the second spacer 921 to form a bulge.

[0452] In some examples, the first and second liner layers 91 and 92 of the liner layer 90 are disposed on the same layer. The first and second liner layers 91 and 92 of the liner layer 90 can be formed using a single patterning process, which can help simplify the manufacturing process of the foldable display panel 100.

[0453] In some embodiments, as shown in FIG18 and FIG19 , the liner layer 90 may further include a third liner layer 93 disposed opposite the first liner layer 91. The third liner layer 93 is located between the first isolation pillar C1 and the first liner layer 91. The third liner layer 93 can further increase the height of the first isolation pillar C1, thereby helping to isolate it from water vapor erosion.

[0454] In some examples, the third liner layer 93 includes multiple third liners 931, and the multiple third liners 931 can correspond one-to-one to the first isolation column C1, and the orthographic projection of the third liners 931 on the substrate 00 at least partially overlaps with the orthographic projection of the first isolation column C1 on the substrate 00.

[0455] Based on this, the third spacer 931 can be used to increase the height of the first isolation column C1, so that the first isolation column C1 can better improve the packaging capability of the light-transmitting area Q of the foldable display panel 100 and help isolate it from water vapor erosion.

[0456] The orthographic projection of the third liner 931 on the substrate 00 at least partially overlaps with the orthographic projection of the first isolation column C1 on the substrate 00 , which may include the following three situations:

[0457] The first type: the orthographic projection of the third liner 931 on the substrate 00 at least partially overlaps with the orthographic projection of the first isolation column C1 on the substrate 00 .

[0458] The second type: the orthographic projection of the third liner 931 on the substrate 00 covers the orthographic projection of the first isolation column C1 on the substrate 00 .

[0459] The third type is that the boundary of the orthographic projection of the third pad 931 on the substrate 00 substantially overlaps with the boundary of the orthographic projection of the first isolation column C1 on the substrate 00 .

[0460] In the embodiments of the present disclosure, for all three of the above methods, the third liner 931 can be used to increase the height of the first isolation column C1, which helps to isolate it from water vapor erosion. Since Figures 18 and 19 mainly illustrate the positions of the first light shielding layer 20 and the black matrix layer 71, Figures 18 and 19 do not illustrate the details of the surface of each film layer. For example, it does not directly illustrate that the third liner 931 causes the film layer below the first isolation column C1 to bulge. However, in an actual foldable display panel, the film layer below the first isolation column C1 should be supported by the third liner 931 to form a bulge.

[0461] In some embodiments, referring to FIG. 18 and FIG. 19 , the liner layer 90 may further include a fourth liner layer 94 disposed opposite the second liner layer 92. The fourth liner layer 94 is located between the second isolation pillars C2 and the second liner layer 92. The fourth liner layer 94 can further increase the height of the second isolation pillars C2, thereby helping to isolate them from moisture erosion.

[0462] In some examples, the fourth liner layer 94 includes multiple fourth liners 941, and the multiple fourth liners 941 can correspond one-to-one to the second isolation column C2, and the positive projection of the fourth liners 941 on the substrate 00 at least partially overlaps with the positive projection of the second isolation column C2 on the substrate 00.

[0463] Based on this, the fourth spacer 941 can be used to increase the height of the second isolation column C2, so that the second isolation column C2 can better improve the packaging capability of the light-transmitting area Q of the foldable display panel 100, and help isolate it from water vapor erosion.

[0464] The orthographic projection of the fourth liner 941 on the substrate 00 at least partially overlaps with the orthographic projection of the second isolation column C2 on the substrate 00, which may include the following three situations:

[0465] The first type: the orthographic projection of the fourth liner 941 on the substrate 00 partially overlaps with the orthographic projection of the second isolation column C2 on the substrate 00 .

[0466] The second type: the boundary of the orthographic projection of the fourth pad 941 on the substrate 00 roughly overlaps with the boundary of the orthographic projection of the second isolation column C2 on the substrate 00 .

[0467] The third type: the orthographic projection of the fourth liner 941 on the substrate 00 covers the orthographic projection of the second isolation column C2 on the substrate 00 .

[0468] In the three methods described above, the fourth liner 941 can be used to increase the height of the second isolation column C2, which helps to isolate the erosion of water vapor. Among them, since Figures 18 and 19 mainly introduce the positions of the first light shielding layer 20 and the black matrix layer 71. Therefore, Figures 18 and 19 do not illustrate the details of the surface of each film layer. For example, it is not directly illustrated that the fourth liner 941 causes the film layer below the second isolation column C2 to bulge. However, in an actual foldable display panel, the film layer below the first isolation column C1 should be supported by the fourth liner 941 to form a bulge.

[0469] In some examples, the third liner layer 93 and the fourth liner layer 94 in the liner layer 90 are provided on the same layer. Based on this, the third liner layer 93 and the fourth liner layer 94 in the liner layer 90 can be formed using a single patterning process, which can help simplify the manufacturing process of the foldable display panel 100.

[0470] FIG20 is a diagram showing the film layer structure of a foldable display panel according to some further embodiments.

[0471] In some embodiments, referring to FIG. 20 and in combination with FIG. 6 , the foldable display panel 100 may further include a second light-shielding layer 01, which surrounds at least a portion of the display area AA, so as to utilize the second light-shielding layer 01 to block light at the edge of the display area AA of the foldable display panel 100, thereby preventing light leakage around the foldable display panel 100.

[0472] In some examples, the second light shielding layer 01 may be a non-closed loop structure, and the second light shielding layer 01 is disposed around a portion of the display area AA.

[0473] In other examples, the second light shielding layer 01 may be a closed-loop structure, and the second light shielding layer 01 is disposed around the display area AA.

[0474] The present disclosure does not specifically limit the above two situations. Both situations can improve the light leakage problem at the edge of the display area AA. The following describes the second situation, in which the second light shielding layer 01 can be a closed-loop structure and is disposed around the display area AA.

[0475] Because the second light-shielding layer 01 surrounds at least a portion of the display area AA, the orthographic projection of the second light-shielding layer 01 on the transparent cover 10 does not overlap with the orthographic projection of the light-transmitting area Q on the transparent cover 10. Therefore, the placement of the second light-shielding layer 01 in the foldable display panel 100 does not affect the PV value at the light-transmitting area Q of the foldable display panel 100. Furthermore, the second light-shielding layer 01 can be positioned on the side of the first protective layer 30 closest to the display substrate 102.

[0476] The “positioning of the second light shielding layer 01 on the side of the first protective layer 30 close to the display substrate 102 ” may include the following situations:

[0477] The first method: as shown in combination with FIG. 6 and FIG. 20 , the second light shielding layer 01 may be disposed between the first protective layer 30 and the transparent cover plate 10 .

[0478] For example, the second light shielding layer 01 may be disposed between the first protective layer 30 and the first adhesive layer F1 .

[0479] For example, the second light shielding layer 01 may be disposed between the transparent cover plate 10 and the first adhesive layer F1 .

[0480] The second method: when the foldable display panel 100 includes the first buffer layer 40 , the second light shielding layer 01 may be disposed between the transparent cover 10 and the first buffer layer 40 .

[0481] For example, the second light shielding layer 01 may be disposed between the transparent cover plate 10 and the second adhesive layer F2 .

[0482] For example, the second light shielding layer 01 may be disposed between the first buffer layer 40 and the second adhesive layer F2 .

[0483] The third method: when the foldable display panel 100 includes a first buffer layer 40 , a second light shielding layer 01 may be disposed between the first buffer layer 40 and the display substrate 102 .

[0484] For example, the second light shielding layer 01 may be disposed between the first buffer layer 40 and the third adhesive layer F3 .

[0485] For example, the second light shielding layer 01 may be disposed between the display substrate 102 and the third adhesive layer F3 .

[0486] Fourth: when the foldable display panel 100 further includes a second buffer layer 50 , a second light shielding layer 01 may be provided between the transparent cover plate 10 and the second buffer layer 50 .

[0487] For example, the second light shielding layer 01 may be disposed between the transparent cover plate 10 and the second adhesive layer F2 .

[0488] For example, the second light shielding layer 01 may be disposed between the second buffer layer 50 and the second adhesive layer F2 .

[0489] Fifth type: when the foldable display panel 100 further includes a second buffer layer 50 , a second light shielding layer 01 may be provided between the second buffer layer 50 and the first buffer layer 40 .

[0490] For example, the second light shielding layer 01 may be disposed between the second buffer layer 50 and the fourth adhesive layer F4 .

[0491] For example, the second light shielding layer 01 may be disposed between the first buffer layer 40 and the fourth adhesive layer F4 .

[0492] The sixth type: When the foldable display panel 100 also includes an encapsulation layer 60 and a color filter structure layer 70, a second light-shielding layer 01 can be set to contact the encapsulation layer 60, and the second light-shielding layer 01 is located on the side of the encapsulation layer 60 away from the display substrate 102, and is on the same layer as the color filter structure layer 70.

[0493] The embodiments of the present disclosure do not specifically limit the above six situations. The above six situations can all improve the light leakage problem at the edge position of the display area AA and will not affect the PV value at the light-transmitting area Q position of the foldable display panel 100.

[0494] In some embodiments, as shown in FIG20 , the second light shielding layer 01 and the first light shielding layer 20 are formed in the same layer. The second light shielding layer 01 and the first light shielding layer 20 can be formed using a single patterning process, which can simplify the manufacturing process of the foldable display panel 100 .

[0495] FIG. 21 is a diagram showing a film layer structure of a foldable display panel according to some further embodiments.

[0496] In some embodiments, referring to FIG. 21 , the first protective layer 30 in the cover assembly 101 may include a groove M, which surrounds at least a portion of the light-transmitting area Q, and the foldable display panel 100 may further include a third light-shielding layer 02, which is disposed in the groove M so that the third light-shielding layer 02 surrounds at least a portion of the light-transmitting area Q.

[0497] Based on this, the third light-shielding layer 02 can be used to prevent light leakage from the light-transmitting area Q. In addition, the third light-shielding layer 02 is disposed in the groove M to prevent the thickness of the third light-shielding layer 02 from causing unevenness in the adjacent adhesive layer. In other words, the problem of unevenness in the surface of the adhesive layer bonded to the first light-shielding layer 20 after bonding can be improved. Thus, the effect of the adhesive layer bonded to the first light-shielding layer 20 on the PV value at the position of the light-transmitting area Q can be reduced, so that the PV value at the position of the light-transmitting area Q is reduced to below 0.8λ. Furthermore, the effect on the propagation direction of light at the position of the light-transmitting area Q can be reduced, thereby improving the clarity of the photographic image and improving the quality of the foldable display panel 100.

[0498] In some examples, the depth of the groove M in the cover assembly 101 is substantially equal to the thickness of the third light shielding layer 02. Based on this, when the third light shielding layer 02 is formed in the groove M, the third light shielding layer 02 can fill the groove M, and the surface of the transparent cover 10 with the third light shielding layer 02 can be made flush.

[0499] Furthermore, the problem of unevenness of the film layer in the light-transmitting area Q caused by the third light-shielding layer 02 can be reduced, the influence of the third light-shielding layer 02 on the PV value at the position of the light-transmitting area Q can be reduced, and the quality of the foldable display panel 100 can be improved.

[0500] It should be noted that due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the difference between the depth of the groove M in the cover assembly 101 and the thickness of the third shading layer 02 fluctuates within the range of 10% of the thickness of the third shading layer 02 / the thickness of the third shading layer 02, it can also be considered that the depth of the groove M in the cover assembly 101 satisfies the thickness of the third shading layer 02.

[0501] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the difference between the depth of the groove M in the cover assembly 101 and the thickness of the third shading layer 02 fluctuates within the range of 5% of the thickness of the third shading layer 02 / the thickness of the third shading layer 02, it can also be considered that the depth of the groove M in the cover assembly 101 satisfies the thickness of the third shading layer 02.

[0502] It should be noted that the materials of the first light-shielding layer 20 and the third light-shielding layer 02 can be the same, the difference is that the position of the first light-shielding layer 20 in the cover assembly 101 is different from the position of the third light-shielding layer 02 in the cover assembly 101.

[0503] In other embodiments, the transparent cover plate 10 or the first buffer layer 40 in the cover plate assembly 101 may also be provided with a groove M. In still other embodiments, the second buffer layer 50 in the cover plate assembly 101 may also be provided with a groove M. The embodiments of the present disclosure are not limited thereto.

[0504] In some embodiments, the first light-shielding layer 20 and the third light-shielding layer 02 can cooperate with each other to prevent light leakage from the light-transmitting area Q. Furthermore, the effect of the first light-shielding layer 20 and the third light-shielding layer 02 on the PV value at the light-transmitting area Q can be reduced, thereby improving the quality of the foldable display panel 100.

[0505] In some of the above embodiments, the position of the first light-shielding layer 20 within the cover assembly 101 is adjusted, while in other embodiments, the position of the first light-shielding layer 20 outside the cover assembly 101 is adjusted. Specifically, by moving the first light-shielding layer 20 downward, the effect of the first light-shielding layer 20 on the PV value at the light-transmitting area Q of the foldable display panel 100 is reduced. The following, in conjunction with the accompanying drawings, provides another foldable display panel 100 that utilizes another method to reduce the effect of the first light-shielding layer 20 on the PV value at the light-transmitting area Q of the foldable display panel 100.

[0506] FIG22 is a structural diagram of a film layer of a foldable display panel according to some further embodiments, and FIG23 is a structural diagram of the cover assembly in FIG22 .

[0507] Referring to Figures 22 and 23 , an embodiment of the present disclosure provides another foldable display panel 100, comprising a display area AA and a light-transmitting area Q. The foldable display panel 100 further comprises a cover assembly 101 and a display substrate 102, wherein the cover assembly 101 is located on the light-emitting side of the display substrate 102. The cover assembly 101 comprises a transparent cover 10, which is located on the light-emitting side of the display substrate 102. The transparent cover 10 in the cover assembly 101 serves to protect the display substrate 102.

[0508] The cover assembly 101 is configured to include a groove M, which surrounds at least a portion of the light-transmitting area Q. The first light-shielding layer 20 is disposed in the groove M so that the first light-shielding layer 20 surrounds at least a portion of the light-transmitting area Q.

[0509] Based on this, the problem of uneven surface of the adhesive layer attached to the first light-shielding layer 20 after attachment can be alleviated. Consequently, the effect of the adhesive layer attached to the first light-shielding layer 20 on the PV value at the light-transmitting region Q can be reduced, lowering the PV value at the light-transmitting region Q to below 0.8λ. Furthermore, the effect on the propagation direction of light at the light-transmitting region Q can be reduced, thereby improving the clarity of photographic images and enhancing the quality of the foldable display panel 100.

[0510] In some examples, the depth of the groove M in the cover assembly 101 is substantially equal to the thickness of the first light shielding layer 20. Based on this, when the first light shielding layer 20 is formed in the groove M, the first light shielding layer 20 can fill the groove M, and the surface of the transparent cover 10 with the first light shielding layer 20 can be made flush.

[0511] Furthermore, the problem of unevenness of the film layer in the light-transmitting area Q caused by the first light-shielding layer 20 can be reduced, the influence of the first light-shielding layer 20 on the PV value at the position of the light-transmitting area Q can be reduced, and the quality of the foldable display panel 100 can be improved.

[0512] It should be noted that due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the difference between the depth of the groove M in the cover assembly 101 and the thickness of the first shading layer 20 fluctuates within the range of 10% of the thickness of the first shading layer 20 / the thickness of the first shading layer 20, it can also be considered that the depth of the groove M in the cover assembly 101 satisfies the thickness of the first shading layer 20.

[0513] In addition, in other examples, due to certain uncontrollable errors (such as manufacturing process errors, equipment accuracy, measurement errors, etc.), when the error floating range of the difference between the depth of the groove M in the cover assembly 101 and the thickness of the first shading layer 20 fluctuates within the range of 5% of the thickness of the first shading layer 20 / the thickness of the first shading layer 20, it can also be considered that the depth of the groove M in the cover assembly 101 satisfies the thickness of the first shading layer 20.

[0514] FIG24 is a diagram showing the film structure of a foldable display panel according to some further embodiments, wherein the structure of the transparent cover plate 10 may be similar to that of the cover plate assembly 101 shown in FIG23 .

[0515] In some embodiments, referring to FIG. 24 and in combination with FIG. 23 , the cover assembly 101 may include a transparent cover 10 , which is located on the light-emitting side of the display substrate 102 . The transparent cover 10 in the cover assembly 101 may protect the display substrate 102 .

[0516] The transparent cover plate 10 may be provided with the aforementioned groove M. That is, the first light-shielding layer 20 may be formed in the groove M in the transparent cover plate 10 so that the first light-shielding layer 20 is embedded in the transparent cover plate 10. This can reduce the problem of unevenness of the film layer in the light-transmitting area Q caused by the first light-shielding layer 20, reduce the impact of the first light-shielding layer 20 on the PV value at the position of the light-transmitting area Q, and improve the quality of the foldable display panel 100.

[0517] The position of the groove M on the transparent cover 10 may include the following two situations:

[0518] The first type: as shown in FIG. 24 , the groove M may be located on a side of the transparent cover plate 10 close to the display substrate 102 .

[0519] Second, the groove M may be located on a side of the transparent cover plate 10 away from the display substrate 102 .

[0520] In both of the above cases, the first light-shielding layer 20 can be embedded in the transparent cover 10 to reduce the problem of unevenness of the Q film layer in the light-transmitting area caused by the first light-shielding layer 20, reduce the influence of the first light-shielding layer 20 on the PV value at the position of the light-transmitting area Q, and improve the quality of the foldable display panel 100.

[0521] FIG25 is a diagram showing the film structure of a foldable display panel according to some further embodiments, wherein the structure of the first protective layer 30 may be similar to that of the cover assembly 101 shown in FIG23 .

[0522] In some embodiments, referring to FIG25 and in combination with FIG23 , the cover assembly 101 may further include a first protective layer 30 . The first protective layer 30 is located on a side of the transparent cover 10 away from the display substrate 102 .

[0523] Based on this, the transparent cover plate 10 can be covered with the first protective layer 30 so that the first protective layer 30 can protect the transparent cover plate 10 , thereby making the cover plate assembly 101 have better hardness and impact resistance.

[0524] In the case where the cover assembly 101 includes a transparent cover 10 and a first protective layer 30, the arrangement of the groove M may include the following two situations:

[0525] 25 , a groove M can be provided on the first protective layer 30. For example, the groove M can be formed on the side of the first protective layer 30 close to the transparent cover 10, so that the groove on the first protective layer 30 is formed inside the cover assembly 101.

[0526] Second, the groove M can be provided on the transparent cover plate 10. For example, the groove M can be located on a side of the transparent cover plate 10 close to the display substrate 102. Alternatively, the groove M can be located on a side of the transparent cover plate 10 far from the display substrate 102.

[0527] In both of the above cases, the first light-shielding layer 20 can be embedded in the cover assembly 101 to reduce the problem of unevenness of the film layer in the light-transmitting area Q caused by the first light-shielding layer 20, reduce the influence of the first light-shielding layer 20 on the PV value at the position of the light-transmitting area Q, and improve the quality of the foldable display panel 100.

[0528] Furthermore, because the transparent cover plate 10 is located on the side of the first protective layer 30 that is closer to the display substrate 102, when the groove M is provided on the transparent cover plate 10, it can be further away from the light-emitting surface of the foldable display panel 100 than when the groove M is provided on the first protective layer 30. Furthermore, the first light-shielding layer 20 embedded in the groove M can also be further away from the light-emitting surface of the foldable display panel 100, thereby further reducing the impact of the first light-shielding layer 20 on the PV value at the position of the light-transmitting area Q, thereby improving the quality of the foldable display panel 100.

[0529] FIG26 is a diagram showing the film structure of a foldable display panel according to some further embodiments, wherein the structure of the first buffer layer 40 may be similar to that of the cover assembly 101 shown in FIG23 .

[0530] In some embodiments, referring to FIG. 26 and in conjunction with FIG. 23 , the cover assembly 101 may further include a first buffer layer 40. The first buffer layer 40 is located on the side of the transparent cover 10 adjacent to the display substrate 102. The first buffer layer 40 may have excellent cushioning and recovery properties, providing excellent shock absorption. Specifically, the first buffer layer 40 can effectively absorb some of the bending stress and also provide a certain degree of protection for the transparent cover 10, preventing it from rupturing when the foldable display panel 100 is subjected to external impact.

[0531] When the cover plate assembly 101 includes the transparent cover plate 10 and the first protective layer 30, the following three situations may be included:

[0532] The first method is to provide the groove M on the transparent cover plate 10. For example, the groove M may be located on a side of the transparent cover plate 10 close to the display substrate 102. Alternatively, the groove M may be located on a side of the transparent cover plate 10 far from the display substrate 102.

[0533] The second method is to provide the groove M on the first protective layer 30. For example, the groove M is formed on a side of the first protective layer 30 close to the transparent cover 10.

[0534] Third method: Referring to FIG. 26 , a groove M may be provided on the first buffer layer 40. For example, the groove M may be formed on a side of the first buffer layer 40 close to the display substrate 102. For example, the groove M may be formed on a side of the first buffer layer 40 away from the display substrate 102.

[0535] In the above three situations, the first light-shielding layer 20 can be embedded in the cover assembly 101 to reduce the problem of unevenness of the film layer in the light-transmitting area Q caused by the first light-shielding layer 20, reduce the influence of the first light-shielding layer 20 on the PV value at the position of the light-transmitting area Q, and improve the quality of the foldable display panel 100.

[0536] Furthermore, because the first buffer layer 40 is located on the side of the first protective layer 30 and the transparent cover plate 10 close to the display substrate 102, when the groove M is provided on the first buffer layer 40, it can be further away from the light-emitting surface of the foldable display panel 100 than when the groove M is provided on the first protective layer 30 or the transparent cover plate 10. Furthermore, the first light-shielding layer 20 embedded in the groove M can also be away from the light-emitting surface of the foldable display panel 100, thereby further reducing the impact of the first light-shielding layer 20 on the PV value at the position of the light-transmitting area Q, thereby improving the quality of the foldable display panel 100.

[0537] FIG27 is a diagram showing the film structure of a foldable display panel according to some further embodiments, wherein the structure of the second buffer layer 50 may be similar to that of the cover assembly 101 shown in FIG23 .

[0538] Furthermore, when the cover assembly 101 includes other film layers, the grooves M may also be formed on these film layers. For example, the cover assembly 101 may further include a second buffer layer 50 disposed between the first buffer layer 40 and the transparent cover 10. The second buffer layer 50 can further disperse impact stress, thereby protecting the transparent cover 10 and preventing the transparent cover 10 from cracking when the foldable display panel 100 is subjected to external impact.

[0539] Based on this, in combination with Figures 27 and 23, the groove M can be formed on the side of the second buffer layer 50 close to the display substrate 102, or the groove M can be formed on the side of the second buffer layer 50 away from the display substrate 102.

[0540] Based on this, when the groove M is set on the second buffer layer 50, it is equivalent to setting the first shading layer 20 embedded in the groove M at a position further away from the light-emitting surface of the foldable display panel 100, thereby further reducing the influence of the first shading layer 20 on the PV value at the position of the light-transmitting area Q, thereby improving the quality of the foldable display panel 100.

[0541] In some embodiments, as shown in Figure 20 and in combination with Figure 6, the foldable display panel 100 may further include a second light-shielding layer 01, which surrounds at least a portion of the display area AA, so as to utilize the second light-shielding layer 01 to block light at the edge of the display area AA of the foldable display panel 100 to prevent light leakage around the foldable display panel 100.

[0542] Since the second light shielding layer 01 surrounds at least a portion of the display area AA, the orthographic projection of the second light shielding layer 01 on the transparent cover plate 10 does not overlap with the orthographic projection of the light-transmitting area Q on the transparent cover plate 10 .

[0543] Based on this, the setting of the position of the second light-shielding layer 01 in the foldable display panel 100 does not affect the PV value at the position of the light-transmitting area Q of the foldable display panel 100.

[0544] Furthermore, the second light shielding layer 01 may be located on the side of the first protective layer 30 close to the display substrate 102. “Locating the second light shielding layer 01 on the side of the first protective layer 30 close to the display substrate 102” may include the following situations:

[0545] The first method is to form the second light shielding layer 01 directly on the side of the first protective layer 30 close to the display substrate 102. Based on this, the second light shielding layer 01 is used to block light around the display area AA of the foldable display panel 100 to prevent light leakage around the foldable display panel 100.

[0546] The second method involves providing a groove corresponding to the second light-shielding layer 01 in the film layer on the side of the first protective layer 30 closest to the display substrate 102. The second light-shielding layer 01 is embedded in the corresponding groove. The film layer on the side of the first protective layer 30 closest to the display substrate 102 may include the first protective layer 30, a transparent cover plate 10, a first buffer layer 40, and a second buffer layer 50. In this manner, the second light-shielding layer 01 blocks light from the display area AA of the foldable display panel 100, preventing light leakage from the periphery of the foldable display panel 100.

[0547] In some embodiments, as shown in FIG20 , the second light shielding layer 01 and the first light shielding layer 20 are formed in the same layer. The second light shielding layer 01 and the first light shielding layer 20 can be formed using a single patterning process, which can simplify the manufacturing process of the foldable display panel 100 .

[0548] FIG28 is a structural diagram of a cover assembly according to some embodiments, wherein the first protective layer 30 is also shown to illustrate the position of the first light shielding layer 20 in the cover assembly 101 .

[0549] Please refer to Figure 28. Some embodiments of the present disclosure provide a cover assembly 101, which includes a light-transmitting area Q11. The cover assembly 101 may include a transparent cover 10 and a first light-shielding layer 20. The first light-shielding layer 20 is arranged on one side of the transparent cover 10, and the first light-shielding layer 20 is arranged around at least a portion of the light-transmitting area Q11.

[0550] When the foldable display panel 100 is subsequently formed and the cover assembly 101 is bonded to the display substrate 102, the light-transmitting region Q11 becomes the light-transmitting region Q of the foldable display panel 100, and one side of the first light-shielding layer 20 can be bonded to the display substrate 102. That is, after the cover assembly 101 and the display substrate 102 are bonded, the first light-shielding layer 20 is located between the transparent cover 10 and the display substrate 102.

[0551] Based on this, the distance between the first light-shielding layer 20 and the light-emitting surface of the foldable display panel 100 can be increased to reduce the effect of the adhesive layer (second adhesive layer F2) bonded to the first light-shielding layer 20 on the PV value at the light-transmitting area Q, thereby reducing the PV value at the light-transmitting area Q to below 0.8λ. Furthermore, the effect on the propagation direction of light at the light-transmitting area Q can be reduced, thereby improving the clarity of photographic imaging and enhancing the quality of the foldable display panel 100.

[0552] In other examples, the cover assembly 101 may further include a first protective layer 30, a first buffer layer 40, and a second buffer layer 50. In this case, the first light shielding layer 20 may be disposed on any one of the three film layers of the transparent cover 10, the first buffer layer 40, and the second buffer layer 50, close to the side of the display substrate 102.

[0553] That is, the first light-shielding layer 20 is moved downward so as to be away from the first protective layer 30, thereby increasing the distance between the first light-shielding layer 20 and the light-emitting surface of the foldable display panel 100. This reduces the effect of the adhesive layer (second adhesive layer F2) bonded to the first light-shielding layer 20 on the PV value at the position of the light-transmitting area Q, thereby reducing the PV value at the position of the light-transmitting area Q to below 0.8λ. Furthermore, the effect on the propagation direction of light at the position of the light-transmitting area Q can be reduced, thereby improving the clarity of the photographic image and enhancing the quality of the foldable display panel 100.

[0554] It should be noted that the cover assembly 101 has a similar structure to the cover assembly 101 in the foldable display panel 100 introduced in the above embodiments. The description of the structure of the cover assembly 101 in the above embodiments may be referred to and will not be repeated here.

[0555] FIG29 is a structural diagram of a cover assembly according to some other embodiments.

[0556] In other examples, as shown in Figures 22, 23 and 29, the cover assembly 101 can be provided with a groove M, which surrounds at least a portion of the light-transmitting area Q11, and the first light-shielding layer 20 is disposed in the groove M so that the first light-shielding layer 20 surrounds at least a portion of the light-transmitting area Q11.

[0557] Based on this, the problem of uneven surface of the adhesive layer attached to the first light-shielding layer 20 after attachment can be alleviated. Consequently, the effect of the adhesive layer attached to the first light-shielding layer 20 on the PV value at the light-transmitting region Q can be reduced, lowering the PV value at the light-transmitting region Q to below 0.8λ. Furthermore, the effect on the propagation direction of light at the light-transmitting region Q can be reduced, thereby improving the clarity of photographic images and enhancing the quality of the foldable display panel 100.

[0558] For the cover assembly 101 provided with a groove, when the cover assembly 101 may also include a first protective layer 30, a first buffer layer 40 and a second buffer layer 50, the groove M may be provided in any one of the four film layers of the transparent cover 10, the first protective layer 30, the first buffer layer 40 and the second buffer layer 50.

[0559] Based on this, when the first light-shielding layer 20 is formed in the groove M, the first light-shielding layer 20 can fill the groove M, and the surface of the cover assembly 101 with the first light-shielding layer 20 can be made flat. Furthermore, the problem of unevenness of the film layer in the light-transmitting area Q caused by the first light-shielding layer 20 can be reduced, and the influence of the first light-shielding layer 20 on the PV value at the position of the light-transmitting area Q can be reduced.

[0560] In this description, the groove M is provided on the transparent cover plate 10 as an example. After the first light-shielding layer 20 fills the groove M, that is, after the first light-shielding layer 20 is embedded in the groove M, the surface of the transparent cover plate 10 with the first light-shielding layer 20 can be made flush. In addition, the problem of unevenness of the film layer in the light-transmitting area Q caused by the first light-shielding layer 20 can be reduced, and the impact of the first light-shielding layer 20 on the PV value at the position of the light-transmitting area Q can be reduced.

[0561] It should be noted that the cover assembly 101 has a similar structure to the cover assembly 101 in the foldable display panel 100 introduced in the above embodiments. The description of the structure of the cover assembly 101 in the above embodiments may be referred to and will not be repeated here.

[0562] In addition, in some embodiments, the cover assembly 101 may also be provided with a second shading layer 01. The structure of the second shading layer 01 is similar to the structure of the second shading layer 01 provided in the cover assembly 101 in the foldable display panel 100 introduced in the above embodiments, and can be combined with the structural description of the second shading layer 01 in the cover assembly 101 in the above embodiments, which will not be repeated here.

[0563] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that a person skilled in the art can conceive within the technical scope disclosed in the present disclosure should be included within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A foldable display panel, characterized in that: The foldable display panel includes a display area and a light-transmitting area; the foldable display panel also includes: The display substrate comprises a via hole area, wherein the via hole area is located in the light transmission area; A transparent cover plate, located on the light-emitting side of the display substrate; A first buffer layer, located between the transparent cover plate and the display substrate; a first protective layer, located on a side of the transparent cover plate away from the first buffer layer, wherein the material of the first protective layer is different from that of the first buffer layer, and the elastic modulus of the first protective layer is greater than that of the first buffer layer; and A first light-shielding layer, wherein the first light-shielding layer is located between the transparent cover plate and the display substrate, and the first light-shielding layer is located between the first buffer layer and the transparent cover plate, or the first light-shielding layer is located between the first buffer layer and the display substrate, the first light-shielding layer surrounds at least a portion of the light-transmitting area, the first light-shielding layer includes a first opening area, and an orthographic projection of the light-transmitting area on the transparent cover plate at least partially overlaps with an orthographic projection of the first opening area on the transparent cover plate.

2. The foldable display panel according to claim 1, characterized in that: Also includes: a second buffer layer, located between the transparent cover plate and the first buffer layer; a material of the second buffer layer is different from that of the first buffer layer, and an elastic modulus of the second buffer layer is less than or equal to that of the first buffer layer; Wherein, the first light shielding layer is located between the second buffer layer and the transparent cover plate, or the first light shielding layer is located between the second buffer layer and the first buffer layer.

3. The foldable display panel according to claim 2, characterized in that: The elastic modulus of the second buffer layer ranges from 5 MPa to 100 MPa.

4. The foldable display panel according to claim 2 or 3, characterized in that: The thickness of the second buffer layer ranges from 50 μm to 200 μm.

5. The foldable display panel according to any one of claims 2 to 4, characterized in that: The thickness of the second buffer layer ranges from 80 μm to 120 μm.

6. The foldable display panel according to claim 1, characterized in that: Also includes: An encapsulation layer, located on a side of the display substrate close to the transparent cover plate; and, a color filter structure layer, located on a side of the encapsulation layer close to the transparent cover plate, the color filter structure layer comprising: a black matrix layer and a color filter unit, wherein the black matrix layer comprises a plurality of second opening regions that are spaced apart and penetrate the black matrix layer, and the color filter unit is located in the second opening region; The first light shielding layer and the black matrix layer are arranged on the same layer.

7. The foldable display panel according to any one of claims 1 to 6, characterized in that: Also includes a bending area located on one side of the display area; The first buffer layer comprises a first side edge and a second side edge which are arranged opposite to each other, and the first side edge is located on a side of the second side edge close to the bending area; The first side includes a first line segment, a first arc transition segment, a second line segment, a second arc transition segment and a third line segment connected in sequence, the second line segment protrudes toward the second side, the second line segment defines a groove structure, the bottom angle of the groove structure is rounded, and the groove structure is located in the bending area.

8. The foldable display panel according to any one of claims 1 to 7, characterized in that: The elastic modulus of the first protective layer ranges from 5.5 GPa to 7.5 GPa.

9. The foldable display panel according to any one of claims 1 to 8, characterized in that: The first protection layer includes a protection substrate, the material of the protection substrate includes transparent polyimide, and the thickness of the transparent polyimide ranges from 50 μm to 80 μm.

10. The foldable display panel according to claim 9, characterized in that: The thickness of the transparent polyimide ranges from 70 μm to 80 μm.

11. The foldable display panel according to claim 9 or 10, characterized in that: The first protection layer further includes a hard coating layer, and the hard coating layer is located on a side of the protection substrate away from the display substrate.

12. The foldable display panel according to claim 11, characterized in that: The thickness of the hard coating layer ranges from 5 μm to 20 μm.

13. The foldable display panel according to any one of claims 1 to 12, characterized in that: The elastic modulus of the first buffer layer ranges from 3.5 GPa to 4.5 GPa.

14. The foldable display panel according to any one of claims 1 to 13, characterized in that: The thickness of the first buffer layer ranges from 20 μm to 100 μm.

15. The foldable display panel according to claim 14, characterized in that: The thickness of the first buffer layer ranges from 20 μm to 50 μm.

16. The foldable display panel according to any one of claims 1 to 15, characterized in that: The first light shielding layer includes a first opening area, and the orthographic projection of the light-transmitting area on the transparent cover plate covers the orthographic projection of the first opening area on the transparent cover plate.

17. The foldable display panel according to any one of claims 1 to 16, characterized in that: Also includes: The second light shielding layer is located on a side of the first protection layer close to the display substrate, and the second light shielding layer surrounds at least a portion of the display area.

18. The foldable display panel according to claim 17, characterized in that: The second light shielding layer is in the same layer as the first light shielding layer.

19. The foldable display panel according to any one of claims 1 to 18, characterized in that: The first protective layer comprises a groove, and the groove surrounds at least a portion of the light-transmitting area; and The display panel further includes a third light shielding layer, and the third light shielding layer is located in the groove.

20. A foldable display device, characterized in that: It comprises the foldable display panel as claimed in any one of claims 1 to 19.

Images