CN102902109A - Flexible display panel - Google Patents

Abstract

The invention provides a flexible display panel, comprising: a first flexible substrate; the second flexible substrate is arranged opposite to the first flexible substrate; and a frame glue between the first flexible substrate and the second flexible substrate for bonding the first flexible substrate and the second flexible substrate, wherein the frame glue is made of an elastic material, the flexible display panel has a curvature radius, and the Young modulus value of the frame glue corresponds to the curvature radius. By adopting the flexible display panel of the invention, the frame glue made of elastic material is arranged between the two substrates, when the flexible element in the flexible display panel is bent, the stress between the frame glue and the substrates can be buffered by the elastic frame glue material, and the structural stability of the flexible element is improved.

Description

A flexible display panel

technical field

The present invention relates to a display panel, in particular to a flexible display panel.

Background technique

With the rapid development of display technology, the display has gradually developed from the early cathode ray tube (Cathode Ray Tube, CRT) display to the current flat panel display (Flat Panel Display, FPD). Compared with flat-panel displays composed of rigid substrates (such as glass substrates), since flexible substrates (such as plastic substrates) have the characteristics of flexibility and impact resistance, research has been carried out in recent years to make active components Flexible displays on flexible substrates.

In the prior art, when making a traditional flexible display, a sealant is first applied between the active element substrate and the opposite substrate, then the active element substrate and the opposite substrate are pressed together, and the display medium is injected into the active element. between the component substrate and the counter substrate, and then seal it. For example, the frame glue is usually a thermosetting resin or an ultraviolet curable glue, which will harden after heating and pressing the two substrates (the active component substrate and the opposite substrate) for pressing. Then, when the flexible display is bent, the hardened frame rubber is often difficult to bend, and even during the bending process, the hardened frame rubber is damaged due to excessive stress, causing the substrate to break or the active components to be damaged, thus affecting to product reliability.

In view of this, how to design an improved flexible display panel to solve the above-mentioned problem that the sealant is often difficult to bend after hardening is a problem to be solved urgently by relevant technical personnel in the industry.

Contents of the invention

Aiming at the above defects of the flexible display panel in the prior art, the present invention provides a novel flexible display panel.

According to one aspect of the present invention, a flexible display panel is provided, including:

a first flexible substrate;

a second flexible substrate disposed opposite to the first flexible substrate; and

a frame glue, located between the first flexible substrate and the second flexible substrate, for bonding the first flexible substrate and the second flexible substrate,

Wherein, the sealant is made of an elastic material, the flexible display panel has a radius of curvature, and the Young's modulus of the sealant corresponds to the size of the radius of curvature .

Preferably, the relationship between the radius of curvature of the flexible display panel and the Young's modulus of the sealant is:

When the radius of curvature is greater than 100mm and less than 200mm, the Young's modulus of the sealant is between 2000MPa and 3000MPa;

When the radius of curvature is greater than 50mm and less than 100mm, the Young's modulus of the sealant is between 1000MPa and 2000MPa; and

When the radius of curvature is less than 50 mm, the Young's modulus of the sealant is less than 1000 MPa.

Preferably, the first flexible substrate and the second flexible substrate are made of plastic material.

Preferably, the frame glue is made of polymethyl methacrylate (acrylic) or epoxy resin (epoxy).

Preferably, the extending direction of the sealant is perpendicular to the first flexible substrate, and the sealant, the first flexible substrate and the second flexible substrate form a closed space for accommodating A display medium. More preferably, the display medium includes a liquid crystal, an electrophoretic display layer or an organic electroluminescence element layer.

With the flexible display panel of the present invention, a frame glue is provided between the first flexible substrate and the second flexible substrate, and the frame glue is made of elastic material. When the flexible element bends, the elastic frame glue material can buffer the stress between the frame glue and the substrate, and improve the structural stability of the flexible element.

Description of drawings

Readers will have a clearer understanding of various aspects of the present invention after reading the detailed description of the present invention with reference to the accompanying drawings. in,

Fig. 1(a) shows a schematic structural diagram of a flexible display panel in the prior art;

Fig. 1(b) shows a schematic diagram of the state where the substrate is broken due to the stress generated between the substrate and the sealant when the flexible display panel in Fig. 1(a) is bent;

Figure 1(c) shows a schematic diagram of the state where the film is partially peeled off due to the stress generated between the substrate and the sealant when the flexible display panel in Figure 1(a) is bent;

Fig. 2 shows a structural block diagram of a flexible display panel according to an embodiment of the present invention; and

FIG. 3 is a schematic diagram of the radius of curvature corresponding to the Young's modulus of the sealant material when the substrate of the flexible display panel in FIG. 2 is bent.

Detailed ways

In order to make the technical content disclosed in this application more detailed and complete, reference may be made to the drawings and the following various specific embodiments of the present invention, and the same symbols in the drawings represent the same or similar components. However, those skilled in the art should understand that the examples provided below are not intended to limit the scope of the present invention. In addition, the drawings are only for schematic illustration and are not drawn according to their original scale.

The specific implementation manners of various aspects of the present invention will be further described in detail below with reference to the accompanying drawings.

FIG. 1( a ) shows a schematic structural diagram of a flexible display panel in the prior art. As shown in FIG. 1(a), the flexible display panel includes a first substrate 101, a second substrate 201 and a sealant 30, and the first substrate 101 is located above the second substrate 201, and the sealant 30 is located between the first substrate 101 and the second substrate 201 . In addition, an optical film layer 103 is provided below the first substrate 101, and an optical film layer 203 is also provided above the second substrate 201. A closed space is formed so as to accommodate a display medium, such as liquid crystal molecules, in the closed space.

In some cases, the flexible component in the flexible display panel does not bend, at this time, the first substrate 101 and the second substrate 201 are parallel to each other, and the bonding position of the sealant 30 and the optical film layer 103 is fixed, In addition, the bonding position between the sealant 30 and the optical film layer 203 is fixed. In other cases, the flexible component in the flexible display panel is bent, and at this time, the first substrate 101 and the second substrate 201 will be deformed to a certain extent. As mentioned above, in the prior art, the frame glue is usually thermosetting resin or ultraviolet curable glue, which will harden after the two substrates 101 and 201 are heated and pressed together, so that the hardened frame glue bends It is relatively difficult, and may even be damaged due to excessive stress, causing the substrate to break or the active components to be damaged.

More specifically, Fig. 1(b) shows a schematic diagram of the state where the substrate is broken due to the stress generated between the substrate and the sealant when the flexible display panel in Fig. 1(a) is bent, and Fig. 1(c) shows the state of Fig. (a) Schematic diagram of the state where the film is partially peeled off due to the stress generated between the substrate and the sealant when the flexible display panel is bent.

Referring to FIG. 1(b), the first substrate 101 and the optical film layer 103 are bent upwards. At this time, due to the large stress, the hardened sealant is connected to a part of the substrate 201b in the second substrate 201 and the optical film layer 203. A part of the film 203b moves upward together. At this time, the second substrate 201 and the optical film layer 203 will be broken, that is, the other part of the substrate 201a of the second substrate 201 and the other part of the film 203a of the optical film layer 203, and the part of the substrate 201b and the optical film layer 203a of the second substrate 201. Part of the film 203b of the film layer 203 is divided.

Referring to FIG. 1( c ), the first substrate 101 and the optical film layer 103 also bend upwards, and the hardened frame sealant moves upward together with a part of the film 203b of the optical film layer 203 due to greater stress. At this moment, other parts of the films 203 a and 203 c of the optical film layer 203 are still located above the second substrate 201 . In this way, the stress suffered by the sealant 30 causes peeling of part of the film of the optical film layer 203 , seriously affecting its optical performance, and even causing the entire flexible display panel to be scrapped.

In order to effectively relieve or reduce the above problems caused by the stress between the substrate and the sealant, FIG. 2 shows a structural block diagram of a flexible display panel according to an embodiment of the present invention.

Referring to FIG. 2 , the flexible display panel includes a first flexible substrate 401 , a second flexible substrate 403 and a frame glue 405 . Wherein, the second flexible substrate 403 is located below the first flexible substrate 401 and is opposite to the first flexible substrate 401 . The sealant 405 is disposed between the first flexible substrate 401 and the second flexible substrate 403, and serves as a sealing member of the flexible display panel, and is used for bonding the first flexible substrate 401 and the second flexible substrate. Flexible substrate 403. For example, on the cross-section of the flexible display panel, the sealant 405 in a frame-like structure as a whole includes a glued portion 405a and another glued portion 405b. It should be pointed out that, unlike the sealant in the prior art, the sealant 405 of the present invention is made of an elastic material, the flexible display panel has a radius of curvature, and the Young's modulus of the sealant 405 (Young's modulus) corresponds to the size of the radius of curvature. When compressive stress occurs between the flexible substrates 401 and 403 and the frame glue 405, the frame glue 405 can relieve or reduce the compression by using the elastic deformation of its own material. stress.

In a specific embodiment, the first flexible substrate 401 and the second flexible substrate 403 are made of plastic materials.

In a specific embodiment, the material of the sealant 405 is polymethyl methacrylate (acrylic) or epoxy resin (epoxy). For example, the Young's modulus of the sealant made of epoxy resin is between 1000MPa and 10000MPa.

In addition, in the above-mentioned FIG. 2, when the flexible display panel is not bent, the extension direction of the sealant 405 is perpendicular to the first flexible substrate 401. By the glue frame 405, the first flexible substrate 401 and the The second flexible substrate 403 forms a closed space for accommodating a display medium. For example, the display medium in the closed space includes a liquid crystal, an electrophoretic display layer, or an organic electroluminescence element layer.

FIG. 3 is a schematic diagram of the radius of curvature corresponding to the Young's modulus of the sealant material when the substrate of the flexible display panel in FIG. 2 is bent.

Referring to FIG. 3 , taking the second flexible substrate 403 as an example, when the leftmost and rightmost sides of the second flexible substrate 403 are bent downward, the second flexible substrate 403 and the sealant 405 form a shape. arc shape. In the present invention, in order to achieve the effect of relieving the stress between the substrate and the sealant by using the sealant made of elastic material, the value between the radius of curvature of the flexible display panel and the Young's modulus of the sealant can be set correspondingly relation.

In more detail, the flexible display panel (the first flexible substrate 401 or the second flexible substrate 403) has a curvature radius R, and the value of the Young's modulus (Young's modulus) of the frame glue 405 and the curvature radius Corresponding to the size of R. When the radius of curvature is greater than 100 mm and less than 200 mm, the Young's modulus of the sealant 405 is between 2000 MPa and 3000 MPa. When the radius of curvature is greater than 50 mm and less than 100 mm, the Young's modulus of the sealant 405 is between 1000 MPa and 2000 MPa. When the radius of curvature is less than 50 mm, the Young's modulus of the sealant 405 is less than 1000 MPa. It can be seen that the greater the value of the Young's modulus of the sealant 405 is, the greater the curvature radius of the flexible display panel is, and thus the greater the rigidity of the flexible display panel is. Conversely, the smaller the value of the Young's modulus of the sealant 405, the smaller the radius of curvature of the flexible display panel. Therefore, the greater the flexibility of the flexible display panel, the smaller the stress between the substrate and the sealant. .

With the flexible display panel of the present invention, a frame glue is provided between the first flexible substrate and the second flexible substrate, and the frame glue is made of elastic material. When the flexible element bends, the elastic frame glue material can buffer the stress between the frame glue and the substrate, and improve the structural stability of the flexible element.

Hereinbefore, specific embodiments of the present invention have been described with reference to the accompanying drawings. However, those skilled in the art can understand that without departing from the spirit and scope of the present invention, various changes and substitutions can be made to the specific embodiments of the present invention. These changes and substitutions all fall within the scope defined by the claims of the present invention.

Claims (6)

1. A flexible display panel, comprising:

a first flexible substrate;

the second flexible substrate is arranged opposite to the first flexible substrate; and

a frame glue between the first flexible substrate and the second flexible substrate for bonding the first flexible substrate and the second flexible substrate,

the frame glue is made of an elastic material, the flexible display panel is provided with a curvature radius, and the numerical value of Young's modulus of the frame glue corresponds to the curvature radius.

2. The flexible display panel of claim 1, wherein the relationship between the curvature radius of the flexible display panel and the young's modulus of the sealant is:

when the curvature radius is larger than 100mm and smaller than 200mm, the Young modulus of the frame glue is between 2000MPa and 3000 MPa;

when the curvature radius is larger than 50mm and smaller than 100mm, the Young modulus of the frame glue is between 1000MPa and 2000 MPa; and

and when the curvature radius is less than 50mm, the Young modulus of the frame glue is less than 1000 MPa.

3. The flexible display panel of claim 1, wherein the first flexible substrate and the second flexible substrate are made of a plastic material.

4. The flexible display panel of claim 1, wherein the sealant is polymethyl methacrylate or epoxy resin.

5. The flexible display panel of claim 1, wherein the extending direction of the sealant is perpendicular to the first flexible substrate, and the sealant, the first flexible substrate and the second flexible substrate form a closed space for accommodating a display medium.

6. The flexible display panel of claim 5, wherein the display medium comprises a liquid crystal, an electrophoretic display layer, or an organic electroluminescent device layer.

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