WO2018117586A1

WO2018117586A1 - Flexible display device and method for transforming display device

Info

Publication number: WO2018117586A1
Application number: PCT/KR2017/014996
Authority: WO
Inventors: 황창순
Original assignee: 황창순
Priority date: 2016-12-19
Filing date: 2017-12-19
Publication date: 2018-06-28
Also published as: KR101815450B1

Abstract

The present invention relates to a flexible display device and a method for transforming a display device. The flexible display device according to the present invention comprises: a display panel which is made of a flexible material and thus is transformable and generates heat in an operating state; and an elastic member which is bonded to one surface of the display panel so as to support the display panel and is configured to change elasticity thereof by heat generated during operation of the display panel by containing Nitinol. Accordingly, when the display panel is in an operating state, the elastic member made of Nitinol has high elasticity and supports the display panel, thereby realizing a stable image, and when the display panel is in a non-operating state, the elastic member becomes flexible and thus the display panel and the elastic member can be easily transformed, such that the display device may be embodied as a rollable or foldable display device.

Description

Flexible display device and variant of display device

The present invention relates to a flexible display device and a method of modifying the display device. More particularly, the present invention relates to a flexible display device and a method of deforming the display device, in which the shape of the display device is adjusted by controlling the elasticity of the member attached to the display panel by heat generated during operation of the display panel.

Electronic devices are provided with display means called display panels to represent images, characters, and the like. The larger the size of the display panel is, the more realistic the image is, but the disadvantage is that the size of the device is larger and takes up more space. For example, large TVs recently released have many screen sizes of 60 inches or more. In addition, in the case of a mobile computing device such as a smart phone, the smaller the screen, the better the portability, but it becomes difficult to see the screen, there is a problem that must meet the screen size and portability at the same time.

In order to solve such a problem, researches on a flexible display device in which a display panel is made of a flexible material to deform the shape are being actively conducted. The flexible display device includes a rollable display device in which a panel is bent, a foldable display device in which a panel is folded, and the like.

On the other hand, a display panel made of a flexible material, such as an organic light-emitting diode (OLED), is usually configured to support it by an elastic panel. If there is no elastic panel, the OLED display panel may be wrinkled or the screen may be broken by an external force. Because it can. Therefore, in the case of a flexible display panel such as an OLED, a stable image may be realized only when combined with an elastic panel.

As a material of an elastic panel, the polymer composite material, such as metal, such as spring stainless steel, and carbon composite material which has a high elasticity value, is used normally. However, when the elasticity of the elastic panel is too high, it is advantageous to support the display panel, but it is difficult to fold or bend the display panel due to the highly elastic elastic panel. That is, in the case of a flexible display panel such as an OLED, a flexible display device is not easily implemented due to a high elastic elastic panel for supporting the same.

Accordingly, in the present invention, when the display panel is operated, the elastic member has a high elasticity to support the display panel, and thus, a stable image can be realized. An object of the present invention is to provide a flexible display device and a method of modifying the display device.

The object of the present invention is a display panel which is made of a flexible material and which can be deformed and generates heat in an operating state; And an elastic member bonded to one surface of the display panel to support the display panel and configured to change elasticity by heat generated during operation of the display panel including nitinol. do.

The elastic member may have a first elastic value at a first temperature corresponding to an operating temperature of the display panel, and may have a second elastic value smaller than the first elastic value at a second temperature smaller than the first temperature. have.

The elastic member is made of a shape memory alloy containing nitinol, wherein the first temperature is preferably the shape recovery temperature of the shape memory alloy.

The flexible display device may further include a driver configured to deform the display panel and the elastic member.

The elastic member may have a first shape at the first temperature, and may be deformed into a second shape that is bent or folded from the first shape by the driving unit at the second temperature.

It is preferable that the said 1st temperature is 30 degreeC-80 degreeC, and the said 2nd temperature is 0 degreeC-30 degreeC.

Preferably, the elastic member has a thickness of 30 micrometers to 200 micrometers.

On the other hand, providing a flexible member made of a flexible material including a display panel and nitinol and bonded to one surface of the display panel to support the display panel; Deforming the display panel from an initial shape to an unfolded shape, wherein the initial shape is bent or folded from the unfolded shape; Operating the display panel; And increasing the elasticity of the elastic member by heating the elastic member by the heat generated from the operated display panel.

The elastic member may be formed of a shape memory alloy including nitinol, and the increasing of the elasticity of the elastic member may include heating the elastic member to a shape recovery temperature of the shape memory alloy.

Increasing the elasticity of the elastic member may include heating the elastic member to 30 ℃ to 80 ℃.

The method may further include providing a display panel made of a flexible material and deformable, and an elastic member including nitinol and bonded to one surface of the display panel to support the display panel; Reducing the elasticity of the elastic member by stopping the operation of the display panel while the display panel is in operation; And deforming the elasticity of the elastic member to deform the display panel from an initial shape to a bent or folded shape.

In the deforming step, the temperature of the elastic member is preferably 0 ° C to 30 ° C.

According to the flexible display device and the method of deforming the display device according to the present invention, the elastic member that supports the display panel is formed of nitinol material, so that the elasticity of the elastic member is reduced due to the slight heat generated in the display panel when the display panel is opened and the image is viewed. Can be increased. In addition, when the power of the display panel is turned off, the soft heat applied to the elastic member made of nitinol disappears and the elastic member becomes flexible, so that the elastic member can be easily deformed, thereby implementing a rollable or foldable display device.

1 is a diagram illustrating a rolled-up state of a rollable display device as a flexible display device according to an exemplary embodiment of the present invention.

FIG. 2 is a diagram illustrating an expanded state of the display device illustrated in FIG. 1.

3 is a diagram illustrating a folded state of a foldable display device as a flexible display device according to another embodiment of the present invention.

FIG. 4 is a view illustrating an expanded state of the display device illustrated in FIG. 3.

5 is a flowchart illustrating a method of modifying a display device according to an exemplary embodiment of the present invention.

6 is a flowchart illustrating a method of modifying a display device according to another exemplary embodiment of the present invention.

7 is a photograph comparing the elasticity of the nitinol plate and the steel plate at room temperature,

8 is a photograph showing that the elasticity of the nitinol plate increases as the temperature increases to become a super-elastic state.

Hereinafter, a flexible display device and a method of modifying the display device according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a partially rolled-up state of a rollable display device as a flexible display device according to an exemplary embodiment of the present invention, and FIG. 2 is a view illustrating an unfolded state of the display device shown in FIG. 1. The apparatus illustrated in the drawings attached to this specification shows only some components representing technical features of the present invention in order to clarify the gist of the present invention, and other components are reduced or omitted, and the drawings are provided for realization of the actual apparatus. It is to be understood that one or more other components not shown in the following can be additionally included.

1 and 2, a flexible display device according to an exemplary embodiment of the present invention includes a display panel 10 and an elastic member 20 attached to one surface of the display panel 10. The display panel 10 is a means for displaying an image, a character, or the like using an applied electric signal. Generally, the display panel 10 is a display unit including a light source unit, an optical sheet, a light guide plate, a reflective sheet, and / or a frame for maintaining a shape. It is. For example, the display panel 10 may be a liquid crystal display (LCD) or an organic light-emitting diode (OLED), but is not limited thereto.

The elastic member 20 is attached to one surface of the display panel 10 to provide elasticity to the display device 10. 1 and 2, the elastic member 20 is composed of one and attached to the rear surface of the display device 10. However, this is merely an example, and in other embodiments, the elastic members 20 may be provided in different numbers and may be attached at different positions from those shown in the drawings. In one embodiment of the present invention, the thickness t of the elastic member 20 is 30 micrometers to 200 micrometers.

In an embodiment of the present invention, the elastic member 20 includes nitinol, and the nitinol material constituting the elastic member 20 has physical properties in which elasticity changes with temperature. For example, the elastic member 20 has a first elastic value at a first temperature, and has a second elastic value smaller than the first elastic value at a second temperature smaller than the first temperature. As the display panel 10 is an electronic device, a predetermined level of heat is generated from the display panel 10 during an operation of displaying an image. In the present specification, the first temperature is heat transmitted when the display panel 10 is operated. It refers to the temperature of the elastic member 20 when it is heated. Since nitinol has a property of increasing elasticity with increasing temperature, the elastic member 20 has a relatively high elasticity so that the display panel 10 can be flatly supported in the first temperature state. For example, the first temperature may be 30 ° C to 80 ° C. More preferably, the first temperature may be 40 ° C to 50 ° C.

On the other hand, the second temperature is lower than the first temperature. The first temperature corresponds to the temperature of the elastic member 20 when heat generated during the operation of the display panel 10 is transferred to the elastic member 20. On the contrary, the second temperature corresponds to the operation of the display panel 10. The temperature of the elastic member 20 at the time of stopping corresponds to room temperature. For example, the second temperature may be 0 ° C to 30 ° C. More preferably, the second temperature may be 25 ° C. or less. Since nitinol has a property of increasing elasticity with increasing temperature, the elastic member 20 is elastically reduced in a second temperature state relatively lower than the first temperature, and thus the shape deformation is easy.

In one embodiment of the present invention, the elastic member 20 is a shape memory alloy for storing a flat shape with the first temperature as the shape recovery temperature. That is, in the state where the temperature of the elastic member 20 is reduced to the second temperature, the elastic member 20 is in a flexible state that can be deformed, but when the temperature of the elastic member 20 increases to the first temperature, the elastic member ( 20 is deformed into a flat shape which is a memorized shape while the elasticity of the elastic member 20 increases.

When the elastic member 20 is formed of a nitinol material having the properties described above, the display panel 10 operates to generate a slight heat corresponding to the first temperature, and the elastic member 20 is relatively at the first temperature. It has a large 1st elasticity value. As a result, since the elastic member 20 is attached to the display panel 10, the display panel 10 is flattened as if it is stretched with an iron while heat is gradually applied to the elastic member 20.

On the contrary, when the operation of the display panel 10 is stopped, the slight heat applied to the elastic member 20 disappears and the elastic member 20 is in a second temperature state, and has a relatively small second elastic value. In this state, the shape of the display panel 10 may be modified by deforming the elastic member 20. For example, the elastic member 20 may be configured such that the elasticity of the elastic member 20 at the second temperature is similar to that of the OLED panel.

Conventionally, in order to flatten a display panel, the steel plate about 80 micrometers in thickness was normally attached behind a display panel. In this case, even though the display panel 10 made of a flexible material such as an OLED can be kept flat without being wrinkled or curled, the flexible display device is not easy because deformation is difficult due to the elasticity of the steel sheet. In addition, when the display panel 10 adheres to and deforms the steel sheet, a bending mark may occur on the steel sheet, thereby causing the display panel 10 to be damaged. On the contrary, when the steel sheet is not attached while using a flexible display panel such as an OLED, there is a problem in that the surface of the display panel 10 is uneven and a so-called shape occurs.

According to the exemplary embodiments of the present invention, by using the elastic member 20 made of nitinol, in which the elasticity increases during operation of the display panel 10 and decreases in elasticity when the display panel 10 is turned off, The problem of the prior art can be solved. That is, when the display panel 10 is to be rolled or folded, the elastic member 20 is in a flexible state so that damage such as bending does not occur. In addition, when power is supplied to the display panel 10 and gradually generates heat, the elastic member 20 is heated to increase the elasticity of the elastic member 20, so that the display panel 10 is flat and a stable screen can be obtained. .

In an exemplary embodiment, the flexible display device further includes a driver 30 to deform the display panel 10 and the elastic member 20. For example, the driving unit 30 is in the form of a roller, and the flexible display device has an arrangement in which the display panel 10 is wound around a roller as illustrated in FIG. 1 and an arrangement in which the display panel 10 is unfolded as shown in FIG. 2. You can switch between forms. Switching of the arrangement may be performed by rotating the drive unit 30 in the form of a roller, but is not limited thereto. In another embodiment, the degree of curvature of the display panel 10 and the elastic member 20 may be adjusted. Other different means may be included in the drive 30. The driver 30 may deform the display panel 10 and the elastic member 20 while the display panel 10 is not operated and the elastic member 20 is flexible.

Meanwhile, the above-described driving unit 30 is merely an example, and in another embodiment, the flexible display device may be configured to be deformed by an attraction force without providing a separate driving unit.

FIG. 3 is a diagram illustrating a folded state of a foldable display device as a flexible display device according to another exemplary embodiment. FIG. 4 is a diagram illustrating an unfolded state of the display device illustrated in FIG. 3.

3 and 4 show that the deformation method of the display panel 10 and the elastic member 20 is folded based on a predetermined line instead of bending and drying as shown in FIGS. 1 and 2. Only there is a difference. The elastic member 20 may be folded together with the display panel 10 by an external force as shown in FIG. 3, and may be deformed in an unfolded state as shown in FIG. 4 when the display panel 10 is to be used. have. In order to implement the foldable display device, the elasticity of the elastic member 20 at the second temperature may fold the elastic member 20 by an external force. When the elastic member 20 in the folded state reaches the first temperature by configuring the elastic member 20 with the shape memory alloy, the display panel 10 is returned to a flat shape which is a stored shape. The elastic member 20 may be comprised so that it may be.

The deformation itself from the shape of FIG. 3 to the shape of FIG. 4 is caused by a driving force of an attraction force or other device, but once the display panel 10 is operated after being unfolded, the slight heat generated in the display panel 10 is reduced to an elastic member ( 20 to increase the elasticity of the elastic member 20, which makes the surface of the display panel 10 flat so that a stable screen can be seen even in the folded portion of the display panel 10.

Other configurations of the embodiments shown in FIGS. 3 and 4 may be the same as or easily understood from the corresponding configurations of the embodiments described above with reference to FIGS. 1 and 2, and thus detailed descriptions thereof will be omitted.

FIG. 5 is a flowchart illustrating a method of deforming a display device according to an exemplary embodiment, and illustrates a process of changing a display panel from a folded or bent state to an unfolded state.

Referring to FIG. 5, the display panel and the elastic member as described above with reference to FIGS. 1 to 4 may be provided (S1). In this case, the display panel has a curved or folded shape as shown in FIGS. 1 and 3, and the display panel is in a non-operating state. In this state, the nitinol elastic member has a second temperature, for example, a temperature of 0 ° C to 30 ° C, and has a flexible elasticity deformable by applying an external force.

Since the elastic member is in a flexible state, the display panel can be deformed from a bent or folded shape to an unfolded shape (S2). This modification may be performed using the driving unit 30 or the attraction of the embodiment described above with reference to FIGS. 1 and 2.

In operation S3, the display panel may be supplied and operated while the display panel is unfolded. When the display panel is operated, the elastic member is heated by the mild heat generated in the display panel, and as a result, the elasticity of the elastic member is increased (S4). For example, the temperature of the elastic member may be 30 ° C. to 80 ° C. during operation of the display panel. Since the elastic member is attached to one surface of the display panel, as the elasticity of the elastic member is increased, the elastic member and the display panel attached thereto are gradually flattened to allow stable viewing.

FIG. 6 is a flowchart illustrating a method of modifying a display device according to still another exemplary embodiment, and illustrates a process of converting an unfolded display panel into a folded or bent state.

Referring to FIG. 6, a display panel and an elastic member as described above with reference to FIGS. 1 to 4 may be provided (S1). In this case, the display panel has an unfolded shape as shown in FIGS. 2 and 4, and the display panel is operated to display characters or images. In this case, due to the mild heat generated in the display panel, the nitinol elastic member has a first temperature, for example, a temperature of 30 ° C. to 80 ° C., and has a relatively high elasticity.

As described above, while the display panel is operating, the operation of the display panel may be stopped in order to change the shape of the display panel (S2). When the operation of the display panel is stopped, the slight heat generated in the display panel disappears, so that the temperature of the elastic member gradually decreases. As the temperature decreases, the elasticity of the elastic member also decreases.

Next, when the temperature is reduced to such an extent that the elastic member becomes flexible, the display panel may be deformed from an unfolded shape to a curved or folded shape (S3). For example, the above deformation may be made in a state where the temperature of the elastic member is 0 ° C to 30 ° C. This modification may be carried out by manpower, or may be carried out using a driving means such as the drive unit 30 of the embodiment described above with reference to FIGS. 1 and 2.

FIG. 7 is a photograph comparing the elasticity of a nitinol plate and a steel plate having a thickness of about 0.1 mm at room temperature, and FIG. 8 is a super-elastic material due to an increase in elasticity of the nitinol plate with increasing temperature. It is photograph which shows state. As shown in Figure 7, it can be seen that Nitinol is more flexible at room temperature. However, the steel sheet has a constant elasticity regardless of the temperature, while nitinol is more flexible at room temperature, the elasticity increases as shown in Figure 8 with increasing temperature. Accordingly, above a certain temperature, the nitinol plate may exhibit higher elasticity than the steel plate. Accordingly, by using nitinol as an elastic member for supporting a flexible display panel such as an OLED, it is possible to achieve stable image quality without crumpling the image of the display panel.

Although the present invention described above has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and variations may be made therefrom. However, such modifications should be considered to be within the technical protection scope of the present invention. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims

A display panel made of a flexible material and capable of deformation and generating heat in an operating state; And

And an elastic member bonded to one surface of the display panel to support the display panel and configured to change elasticity by heat generated during operation of the display panel including nitinol.
The method of claim 1,

The elastic member has a first elastic value at a first temperature corresponding to an operating temperature of the display panel, and has a second elastic value smaller than the first elastic value at a second temperature smaller than the first temperature. Flexible display device characterized in that.
The method of claim 2,

And the elastic member is formed of a shape memory alloy including nitinol, and the first temperature is a shape recovery temperature of the shape memory alloy.
The method of claim 2,

And a driving unit configured to deform the display panel and the elastic member.
The method of claim 4, wherein

The elastic member,

Has a first shape at the first temperature,

And at the second temperature, deform to a second shape that is bent or folded from the first shape by the driving unit.
The method of claim 2,

The first temperature is 30 ℃ to 80 ℃,

The second temperature ranges from 0 ° C to 30 ° C.
The method of claim 1,

The thickness of the elastic member is 30 to 200 micrometers, the flexible display device.
Providing an elastic member including a display panel and a nitinol made of a flexible material and bonded to one surface of the display panel to support the display panel;

Deforming the display panel from an initial shape to an unfolded shape, wherein the initial shape is bent or folded from the unfolded shape;

Operating the display panel; And

And increasing the elasticity of the elastic member by heating the elastic member by the heat generated from the operated display panel.
The method of claim 8,

The elastic member is made of a shape memory alloy containing nitinol,

The increasing of the elasticity of the elastic member may include heating the elastic member to a shape recovery temperature of the shape memory alloy.
The method of claim 8,

The increasing of the elasticity of the elastic member may include heating the elastic member to 30 ° C to 80 ° C.
Providing an elastic member including a display panel made of a flexible material and deformable and a nitinol, the elastic member being bonded to one surface of the display panel to support the display panel;

Reducing the elasticity of the elastic member by stopping the operation of the display panel while the display panel is in operation; And

And deforming the display panel from an initial shape to a bent or folded shape after reducing the elasticity of the elastic member.
The method of claim 11,

The deformation method of the display device, characterized in that the temperature of the elastic member in the deforming step is 0 ℃ to 30 ℃.