TWI661344B - Display device - Google Patents

Abstract

A display device includes a flexible display panel, a support layer, and a buffer layer. A flexible display panel is disposed above the support layer, and the support layer is disposed above the buffer layer. In the display device, the Young's coefficient of the support layer is greater than the Young's coefficient of the buffer layer, and the damping coefficient of the buffer layer is greater than or equal to 0.25.

Description

Display device

The present invention relates to an electronic device, and more particularly to a flexible display device.

Different from the flat display technology currently widely used in electronic devices such as computer screens, television screens, and mobile phones, the display screen can only be displayed on a fixed flat surface. Flexible display technology has the characteristics of bending or curling. With the recent development of display technology, flexible display technology has begun to attract the attention of a large number of consumer device manufacturers, and this type of display technology has also begun to be applied to consumer electronic products such as e-readers and mobile phones. in.

In order to provide a flexible effect, a flexible display device is manufactured based on a flexible substrate. Flexible substrates include flexible metal, glass, or plastic materials. The thickness of these flexible substrates is lower and the impact resistance is reduced accordingly. Compared with the existing flat display device, the flexible display device has a poorer performance in the impact test such as a falling ball test. Since the flexible display device can be deformed with external force, the position where the sphere strikes will be greatly deformed, which will damage the electronic components there, and even damage the entire display device. Therefore, how to make a flexible display device with anti-impact capability is one of the problems to be solved in current display technology.

An object of the present invention is to provide a display device having impact resistance force.

The display device of the present invention includes a flexible display panel, a support layer, and a buffer layer. A flexible display panel is disposed above the support layer, and the support layer is disposed above the buffer layer. In the display device, the Young's coefficient of the support layer is greater than the Young's coefficient of the buffer layer, and the damping coefficient of the buffer layer is greater than or equal to 0.25.

With the support layer and the buffer layer described above, the pressure on the flexible display panel can be absorbed by the buffer layer, thereby improving the impact resistance of the display device.

A‧‧‧ projection area

d‧‧‧direction

F‧‧‧Strength

50‧‧‧ sphere

100, 200, 300, 400, 500, 600‧‧‧ display device

110, 210‧‧‧ flexible display panel

111, 410A, 510A, 610A‧‧‧ Protective layer

112‧‧‧touch layer

113‧‧‧polarizing layer

114‧‧‧Display layer

120, 220, 320, 420, 520, 620‧‧‧ support layers

130, 230, 430, 530, 630‧‧‧ buffer layer

140, 240, 440, 540, 640‧‧‧ housing

220A, 220B, 320A, 320B ‧‧‧ sub support

242, 244‧‧‧ Sub-shell

246‧‧‧Shaft

250‧‧‧ connection layer

350C‧‧‧Slotted

410B, 510B, 610B‧‧‧ flexible display layer

401, 501, 601‧‧‧‧Transparent adhesive layer

402, 502, 602‧‧‧‧ first adhesive layer

403, 603‧‧‧Second adhesive layer

404, 503‧‧‧shell adhesive layer

1 is a schematic perspective view of a display device according to a first embodiment of the present invention; FIG. 2A is a schematic sectional view according to a section line I of FIG. 1; and FIG. 2B is a schematic sectional view of a display device according to the first embodiment when it is impacted FIGS. 3A to 3C are schematic diagrams of manufacturing the display device of the first embodiment; FIGS. 4A to 4B are schematic diagrams of manufacturing another display device of the first embodiment; FIGS. 5A to 5B are 5C is a schematic cross-sectional view of a display device according to a third embodiment of the present invention; and FIGS. 6A to 6C are schematic cross-sectional views of a display device of other embodiments of the present invention.

The proposed display device of the present invention can be applied, for example, to a display screen of a portable electronic device such as a mobile phone, a tablet computer, a notebook computer, an e-reader, etc., or can be applied to a computer screen, a television screen, and the like. The flexible characteristics provide an appropriate curved display. On the other hand, the display device provided by the present invention is not limited to the type of display technology. It can be applied to display technologies such as e-paper and Organic Light Emitting Diode (OLED). Hereinafter, several embodiments will be listed to describe the display device proposed by the present invention in detail.

FIG. 1 is a schematic perspective view of a display device according to a first embodiment of the present invention. Referring to FIG. 1, the display device 100 includes a flexible display panel 110. The flexible display panel 110 may be, for example, an electronic paper or an OLED display panel, preferably an OLED display panel with a touch panel. The touch OLED display panel is taken as an example below, but the present invention is not limited thereto.

The flexible display panel 110 in this embodiment includes a protective layer 111, a touch layer 112, a polarizing layer 113, and a display layer 114. The protective layer 111 is made of a flexible material. For example, the material of the protective layer 111 includes a plastic material such as polyethylene terephthalate (PET), polyimide (PI), or ultra-thin glass, and its Young's coefficient ( Young's modulus) falls in the range of 3 GPa to 80 GPa, and the thickness falls in the range of 50 micrometers to 150 micrometers, but the present invention is not limited to the thickness and material characteristics of the protective layer.

The flexible display panel 110 has a characteristic that it can be deformed, bent, or curled with an external force, and can also be bent with a surface provided. For example, the flexible display panel 110 of this embodiment is disposed on a casing 140 through a supporting layer 120 and a buffer layer 130 described in detail below, and the flexible display panel 110 may follow the surface of the casing 140. Bend and bend.

The display device 110 of this embodiment further includes a support layer 120 and a buffer layer 130. The flexible display panel 110 is disposed on the support layer 120, and the support layer 120 is disposed on the buffer layer 130. In other words, the support layer 120 and the buffer layer 130 form a multilayer structure for the flexible display panel 110 to be disposed, and the support layer 120 is located between the flexible display panel 110 and the buffer layer 130.

The support layer 120 and the buffer layer 130 of this embodiment have different elasticities. When an external force is applied, the strain of the support layer 120 is lower than that of the buffer layer 130. The coefficient is high. In other words, the support layer 120 provides a platform with higher stiffness for the flexible display panel 110 to be disposed.

Because the pressure is related to the magnitude of the force and the size of the surface on which the force is dispersed, when the flexible display panel 110 is impacted by an external force, the support layer 120 can quickly disperse the force across the entire surface, and the pressure caused by the external force is also reduced. The following will be further described with a schematic sectional view.

For example, referring to the schematic cross-sectional view shown in FIG. 2A, the support layer 120 and the buffer layer 130 in this embodiment are stacked along the direction d to form a platform for the flexible display panel 110 to be disposed, and the flexible display panel 110 is provided. The connected support layer 120 has a high Young's coefficient. When the flexible display panel 110 is impacted by an external force, please refer to FIG. 2B together. In addition, the external force F provided by the falling ball 50 is taken as an example. The flexible display panel 110 transmits the external force F to the supporting layer 120. The supporting layer 120 spreads the force laterally across the entire surface by its material characteristics; the pressure applied by the supporting layer 120 downward to the buffer layer 130 decreases as the area of the dispersion increases, and the amount of deformation of the buffer layer 130 is reduced, making The flexible display panel 110 can receive a small reaction force, and the element is not damaged due to an excessive amount of deformation.

On the other hand, the material of the support layer 120 may be, for example, plastic materials such as poly (methyl methacrylate, PMMA), acrylic resin (Acrylic); magnesium, nickel, titanium, aluminum, copper, iron, stainless steel And other metal materials; carbon fiber or ultra-thin glass, whose Young's modulus falls in the range of 1GPa to 250GPa, and the thickness falls in the range of 15 microns to 2000 microns.

The buffer layer of this embodiment can provide an isolation effect, and a damping coefficient thereof is greater than or equal to 0.25. Explanation Definition Here, the damping coefficient is represented by, for example, tan δ, and tan δ is a ratio of a loss modulus and a storage modulus. The storage modulus is the elastic properties of the material and the ability to store energy, and the loss modulus is the viscosity properties of the material and the ability to consume energy.

For example, please refer to FIG. 2B. When the impact force F of the sphere 50 is received, the storage modulus may correspond to the initial kinetic energy of the sphere when it contacts the surface of the object and receives a reaction force, and the loss modulus may correspond to the sphere leaving The difference between the initial kinetic energy and the remaining kinetic energy after the energy is lost due to deformation and other factors on the surface of the object. In short, the larger the damping coefficient, the better the ability of the buffer layer 130 to absorb and dissipate external forces, and thus the external force that the flexible display panel 110 can dissipate.

Further, the buffer layer 130 of this embodiment can absorb the impact between the shell 140 and the support layer 120 and provide a good vibration isolation effect between the two.

Since the display device 100 of this embodiment has a supporting layer 120, the external force received by the flexible display panel 110 can be spread to a large area; and by the absorption and dissipation effect of the buffer layer 130, the flexible display panel 110 can avoid the excessive High local external force causes large deformation and damage. The results of several test experiment examples are listed below.

In this experimental example, an impact test is performed on three display devices by using a falling ball, and the lateral stress and vertical stress of each display device under impact are measured, where the vertical stress is parallel to the display surface of the display device (that is, the surface impacted by the sphere). The normal vector, the lateral stress is perpendicular to the normal vector.

The above three display devices are respectively set as follows: Display device A: the flexible display panel is directly provided on the housing; display device B: the flexible display panel is provided on the housing through a cushioning material, such as a commercially available shock-absorbing material; display device C: flexible display The panel is disposed on the casing through the support layer and the buffer layer described above. The mass of the sphere is 32 grams, the diameter of the sphere is 19.8 mm, and the height of the falling ball is 60 mm; the Young's coefficient of the buffer layer is 0.45 MPa, the thickness is 300 micrometers, and the damping coefficient tan δ is about 0.6; the Young's coefficient of the support layer It was 70 GPa and the thickness was 100 micrometers.

When a sphere impacts these display devices, the lateral stress of display device A is 498 MPa, the lateral stress of display device B is 275 MPa, the lateral stress of display device C is 212 MPa; the vertical stress of display device A is 1244 MPa, and the display device The vertical stress of B is 109 MPa, and the vertical stress of display device C is 57 MPa. It can be known from the above experimental results that a display device including a support layer and a buffer layer can obviously allow the internal flexible display panel to bear lower vertical stress and lateral stress, thereby improving the impact resistance of the display device.

The support layer and the buffer layer of the display device provided by the present invention can be matched with various flexible display panels with different hardness requirements. The thickness and hardness relationships of the buffer layer and the support layer in the examples of the present invention will be enumerated below.

When the Young's coefficient of the protective layer of the flexible display panel of an embodiment is, for example, 5.8 GPa, and the thickness is, for example, 125 micrometers. The Young's coefficient of the support layer can be, for example, 70 GPa, and the thickness can be 1000 micrometers; the Young's coefficient of the buffer material can be 0.3 MPa, and the thickness can be 300 micrometers. In another embodiment, a flexible display panel with the same protective layer can also be used with a supporting layer having a Young's coefficient of 200 GPa, a thickness of 500 microns, and a buffer material with a Young's coefficient of 0.3 MPa and a thickness of 300 microns.

When the Young's coefficient of the protective layer of the flexible display panel according to an embodiment is 70 GPa, for example, the thickness is 75 micrometers. The Young's coefficient of the support layer can be, for example, 70 GPa, and the thickness can be 500 micrometers; the Young's coefficient of the buffer material can be 0.3 MPa, and the thickness can be 300 micrometers. In another embodiment, a flexible display panel having the same protective layer can also be used with a supporting layer having a Young's coefficient of 200 GPa, a thickness of 250 micrometers, and a buffer material having a Young's coefficient of 0.3 MPa and a thickness of 300 micrometers.

It can be known from the above that the thickness of the support layer can be reduced as the Young's coefficient is increased; the thickness of the buffer material can also be decreased as the damping coefficient is increased. Furthermore, the thickness of the protective layer can be reduced as the Young's coefficient is increased. For those having ordinary knowledge in the art, the thickness of the support layer, the buffer layer, and the protective layer may be determined according to requirements and materials, and the present invention is not limited thereto.

On the other hand, please refer to the above-mentioned FIGS. 1 to 2A regarding the first embodiment of the present invention, wherein the support layer 120 provides a large-area riding platform for the flexible display panel 110 to be disposed. In detail, when the flexible display panel 110 is disposed on the support layer 120, the vertical projection area A of the flexible display panel 110 on the support layer 120 is located within the outline of the support layer 120, that is, the support layer 120 faces the flexibility. A surface area of the display panel 110 is greater than or equal to an area of a distribution area of the flexible display panel 110. Therefore, the supporting layer 120 can effectively disperse the impact force received by the flexible display panel 110.

The buffer layer 130 of this embodiment also provides a suitable platform for the support layer 120 and the flexible display panel 110 to be disposed. When the flexible display panel 110 and the support layer 120 are disposed on the buffer layer 130, the vertical projection area A of the flexible display panel 110 on the buffer layer 130 is located within the outline of the buffer layer 130, that is, the buffer layer 130 faces the flexibility. The surface area of the display panel 110 is larger than or equal to The area of the distribution area of the flexible display panel 110. Therefore, the buffer layer 130 can effectively absorb an impact force from the flexible display panel 110.

In terms of assembly methods, the display device of the present invention also provides a variety of suitable mounting methods, and several items will be listed below for explanation. Referring to FIG. 3A, when the display device 100 according to the first embodiment of the present invention is manufactured, the flexible display panel 110 may be first disposed on the support layer 120. Referring to FIG. 3B, the buffer layer 130 may be disposed on the casing 140 first. Referring to FIG. 3C, after the above two laminations are completed, the supporting layer 120 carrying the flexible display panel 110 is disposed on the buffer layer 130 on the casing 140. In short, the support layer 120 can initially strengthen the structure of the flexible display panel 110 so that the flexible display panel 110 can be easily mounted on the device casing 140.

In the display device 100 according to the first embodiment of the present invention, the platform under the flexible display panel 110 can be manufactured first. Please refer to FIG. 4A. In this method, the buffer layer 130 and the support layer 120 are disposed on the casing 140, and a platform for setting the flexible display panel 110 is completed in advance. Referring to FIG. 4B, the flexible display panel 110 is directly disposed on the support layer 120, the buffer layer 130 and the casing 140 to complete the assembly of the display device. By completing the platform for setting the flexible display panel in advance, the above-mentioned assembly method can also improve the overall production efficiency.

The display device of the present invention can be further applied to a bendable display device. 5A, a display device 200 according to a second embodiment of the present invention is similar to the display device 100 described above, and includes a flexible display panel 210 and a buffer layer 230; the support layer 220 is formed by the sub-supporting portion 220A and the sub-supporting portion 220B; The body 240 is formed by the sub-housings 242 and 244 and a rotating shaft 246 that connects the two and can rotate along the axis R.

The display device 200 of this embodiment further includes a connection layer 250 that extends along an axis R. The connection layer 250 is located between the sub-supporting portion 220A and the sub-supporting portion 220B, and Connect with both separately. In addition, the support layer may be bent along an extension axis of the connection layer 250.

Specifically, referring to FIG. 5B, when the casing is bent with the axis R as the axis, the supporting layer on the buffer layer 230 may be bent to bring the sub-supporting portion 220A closer to the sub-supporting portion 220B. The connection layer 250 is adapted to be bent and connected to the sub-supporting portion 220A and the sub-supporting portion 220B at two sides, respectively. In this embodiment, the Young's coefficient of the connection layer 250 is lower than the Young's coefficient of the sub-support portions 220A and 220B. Specifically, the material of the connection layer 250 is, for example, silicone, rubber, or foam. The Young's coefficient is less than or equal to 0.1 GPa, and the thickness can be designed with the requirements of the sub-supports 220A, 220B and bending. The thickness is between 15 and 2000 micron range.

On the other hand, the width of the connection layer 250 also corresponds to the requirement of bending to provide a good bending effect. Please refer to FIG. 5A. The relationship between the maximum width of the connecting layer 250 on the axis perpendicular to the extending layer and the minimum radius of curvature during bending is as follows: πr ≦ L ≦ πr + 20, where L is the above-mentioned maximum width, r Is the minimum radius of curvature when bending, that is, the radius of curvature when the support layer is bending the most. Therefore, during the bending, the sub-supporting portions 220A and 220B connected by the connecting layer 250 can still provide a good effect of dispersing force, and at the same time can provide a good bending function.

The display device of the present invention is not limited to the connection layer 250 described above. 5C, the support layer 320 of the display device 300 according to the third embodiment is composed of sub-support portions 320A and 320B, and the sub-support portions 320A and 320B are connected by a connection layer. The connection layer of this embodiment includes a plurality of slots. 350C, so that the support layer can compress these slotted 350C to provide good bending function during bending.

Hereinafter, several embodiments will be listed to explain the manufacturing method of the display device of the present invention. law. Referring to FIG. 6A, a display device 400 according to a fourth embodiment of the present invention includes a protective layer 410A, a flexible display layer 410B, a support layer 420, a buffer layer 430, and a case 440 similar to the display device 100 described above, in which the flexible display layer 410B A flexible display panel similar to the above is formed with the protective layer 410A. Specifically, the flexible display layer 410B of this embodiment is connected to the protective layer 410A through the light-transmissive adhesive layer 401. The light-transmissive adhesive layer 401 is, for example, an optical clear adhesive layer (Optical Clear Adhesive, OCA) or a light-transparent resin ( Optical Clear Resin (OCR), whose thickness preferably falls in the range of 25 to 100 microns.

The flexible display layer 410B of this embodiment is connected to the support layer 420 through the first adhesive layer 402. Specifically, the first adhesive layer 402 is, for example, an optically transparent adhesive layer, an optically transparent resin layer, or an optical adhesive layer; or epoxy, acrylic, silicon, or polyurethane. And other non-optical adhesives, and the thickness of the first adhesive layer 402 falls within a range of 12 to 100 microns.

The support layer, the buffer layer, and the casing in the display device of the present invention may also be bonded by an adhesive layer. The support layer 420 of this embodiment is connected to the buffer layer 430 through the second adhesive layer 403, and the buffer layer 430 is connected to the housing 440 through the shell adhesive layer 404. Specifically, the second adhesive layer 403 and the shell adhesive layer 404 are, for example, optical adhesive layers such as optically transparent adhesive layers and optically transparent resins; or epoxy, acrylic, and silicone ( silicon) or polyurethane (Urethane), and the thickness of these adhesive layers is preferably in the range of 8 to 50 microns.

The connection between the support layer, the buffer layer and the casing of the present invention is not limited to the above-mentioned connection manner. Referring to FIG. 6B, a display device 500 according to a fifth embodiment of the present invention is similar to the display device 400 described above, and the light-transmissive adhesive layer 501 is connected to the protective layer 510A forming a flexible display panel. And the flexible display layer 510B; the flexible display layer 510B and the support layer 520 are connected by a first adhesive layer 502; the buffer layer 530 and the casing 540 are connected by a casing adhesive layer 503. Different from the above display device 400, the buffer layer 530 of this embodiment is directly foamed and formed on the support layer 520, that is, the resin layer and the foaming agent are directly heated and foamed to form the buffer layer 530 on the support layer. 520 on.

On the other hand, the buffer layer can also be formed on the shell by foaming. 6C, a buffer layer 630 in a display device 600 according to a sixth embodiment of the present invention is formed on the casing 640 by foaming, and then the support layer 620 is connected to the buffer layer 630 by a second adhesive layer 603. The first adhesive layer 602 and the light-transmissive adhesive layer 601 sequentially connect the flexible display layer 611B and the protective layer 611B to the support layer 620.

In summary, the flexible display panel in the display device of the embodiment of the present invention is disposed on the support layer, and the support layer is further disposed on the buffer layer, so the impact force received by the flexible display panel can be dispersed in the support layer. At the same time, the impact force can be absorbed by the buffer layer, thereby improving the impact resistance of the display device.

Claims (15)

A display device includes: a flexible display panel; a support layer, the flexible display panel is disposed on the support layer; and a buffer layer, the support layer is disposed on the buffer layer; Its coefficient is greater than the Young's coefficient of the buffer layer, and the damping coefficient of the buffer layer is greater than or equal to 0.25. The display device according to item 1 of the scope of patent application, wherein the Young's coefficient of the support layer is 1 Gpa to 250 GPa. The display device according to item 1 of the scope of patent application, wherein a vertical projection area of the flexible display panel on the support layer is located within a contour range of the support layer. The display device according to item 1 of the scope of patent application, wherein a vertical projection area of the flexible display panel on the buffer layer is located within a contour range of the buffer layer. The display device according to item 1 of the patent application scope further includes a connection layer, wherein the support layer includes two sub-support portions side by side, the connection layer connects the two sub-support portions; the connection layer extends along an axis, and the support The layer is bent along the axis so that the two sub-support portions connected by the connection layer are close to each other. The display device according to item 5 of the patent application, wherein the connection layer has at least one slot. The display device according to item 5 of the application, wherein the Young's coefficient of the connection layer is smaller than the Young's coefficient of the support layer. The display device according to item 5 of the scope of patent application, wherein the Young's coefficient of the connection layer is less than 0.1 GPa. The display device according to item 5 of the scope of patent application, wherein the maximum width of the connection layer in a direction perpendicular to the axis line and the minimum radius of curvature of the connection layer when bent are: πr L πr +20 where r is the minimum radius of curvature when the connecting layer is bent, and L is the maximum width. The display device according to item 1 of the scope of patent application, further comprising: a casing, the flexible display panel is connected to the casing via the supporting layer and the buffer layer, and the buffer layer is located on the casing and the supporting layer between. According to the display device of claim 10, the buffer layer is formed by foaming the casing. According to the display device described in claim 10, the buffer layer is adhered to the casing by a casing adhesive layer. According to the display device described in item 1 of the patent application scope, the support layer is adhered to the flexible display panel through a first adhesive layer. According to the display device described in item 1 of the patent application scope, the buffer layer is adhered to the support layer through a second adhesive layer. According to the display device described in item 1 of the patent application scope, the buffer layer is formed by foaming the support layer.