KR102338062B1 - Shape memory composite and variable display device - Google Patents

Abstract

A shape memory composite according to an embodiment of the present invention includes a shape memory layer, an insulating layer positioned on the shape memory layer, a heat supply layer positioned on the insulating layer, a protective layer positioned on the heat supply layer, and and a heat dissipation layer positioned below the shape memory layer.

Description

A shape memory complex and a variable display device including the same

The present invention relates to a shape memory composite and a variable display device including the same, and more particularly, to a shape memory composite capable of reducing the variable driving time of a variable display device by improving the driving force and reactivity of the shape memory composite, and a variable type display including the same It is about the display device.

In recent years, the importance of a display device is increasing with the development of multimedia. In response to this, Liquid Crystal Display (LCD), Plasma Display Panel (PDP), Field Emission Display (FED), Organic Light Emitting Diode Display Device (OLED) ), and various flat display devices such as an electrophoretic display (EPD) are being put to practical use.

Recently, the portability of a display device is required so that information can be accessed at a desired time and place, and lightness for portability is also required. Such a portable display device requires a display unit for displaying images in order to support various functions, and it is difficult to form a display unit having a size larger than a certain size due to spatial restrictions due to portability and other device arrangements during the manufacture of a terminal. However, with the development of a display unit that can satisfy these spatial constraints and portability, a foldable display device has been recently proposed.

The variable display device uses a motor to allow a panel made of flexible materials to have an appropriate curvature. In the case of mobile, when a motor is used, noise from the motor driving unit and a motor unit must be provided. To this end, additional components other than the back plate take up the volume of the display device, which is reduced to a thick and heavy phone.

In order to solve this problem, it is trying to drive by self-heating by using shape memory alloy rather than a motor method. However, in the case of commonly used nitinol, the resistance value is low (less than 1.0), so in order to actually generate self-heating, it must be designed as a thin and long wire of a wire type to generate heat, and thus the shape can be deformed. . However, in order to bend the mobile, it must have a fairly large bending force, so it cannot be applied to the wire type. Therefore, the shape memory alloy must be a wire type for self-heating, but there is a problem in that it has to go to a sheet type in order to generate force.

The present invention provides a shape memory composite capable of reducing a variable driving time of a variable display device by improving driving force and reactivity of the shape memory composite, and a variable display device including the same.

In order to achieve the above object, the shape memory composite according to an embodiment of the present invention includes a shape memory layer, an insulating layer positioned on the shape memory layer, a heat supply layer positioned on the insulating layer, and the heat supply layer It characterized in that it comprises a protective layer positioned on the, and a heat dissipation layer positioned under the shape memory layer.

The shape memory layer is characterized in that it consists of a sheet shape.

The heat supply layer is characterized in that it comprises a planar heating layer and electrodes positioned on both sides of the planar heating layer.

The shape memory composite has a thickness of 0.1 mm to 1 mm.

In addition, the variable display device according to an embodiment of the present invention includes a main frame, a display panel positioned on the main frame, a cover positioned on the display panel, at least one shape memory complex positioned under the main frame, and a rear cover coupled to the cover to accommodate the display panel, the main frame, and a shape memory composite, wherein the shape memory composite includes a shape memory layer, an insulating layer positioned on the shape memory layer, and positioned on the insulating layer a heat supply layer, a protective layer positioned on the heat supply layer, and a heat dissipation layer positioned below the shape memory layer.

The display device may further include a stopper positioned under the main frame, wherein the stopper is interlocked and fixed with each other by a bending or unfolding force of the shape memory composite, thereby maintaining the shape of the variable display device.

It is located under the main frame and further includes a fixing part including a ball, wherein the fixing part is moved and fixed by the force of bending or unfolding the shape memory complex, thereby maintaining the shape of the variable display device It is characterized as a means to do it.

It characterized in that it further comprises a slide plate located under the main frame, wherein the slide plate is a means for maintaining the shape of the variable display device by moving and fixing the shape memory complex by a bending or unfolding force. .

The shape memory composite according to an embodiment of the present invention and a variable display device including the same have an advantage in that the variable driving time of the variable display device can be shortened by improving the driving force and reactivity of the shape memory composite. In addition, by providing various fixing members to the variable display device having the shape memory composite, there is an advantage in that the shape memory composite can be maintained in a curved or flat shape without driving.

1 is a diagram schematically illustrating a driving principle of a shape memory alloy according to an embodiment of the present invention.
2 is a view showing a shape memory composite according to an embodiment of the present invention.
Figure 3a is an image showing the shape memory alloy wire used in Example 1 of the present invention, Figure 3b is a graph measuring the exothermic temperature according to the voltage applied to the shape memory alloy wire according to Example 1 of the present invention.
Figure 4a is an image showing the shape memory alloy wire used in Example 2 of the present invention, Figure 4b is a graph measuring the exothermic temperature according to the voltage applied to the shape memory alloy wire according to Example 2 of the present invention.
Figure 5a is an image showing the shape memory alloy wire used in Example 3 of the present invention, Figure 5b is a graph measuring the exothermic temperature according to the voltage applied to the shape memory alloy wire according to Example 3 of the present invention.
Figure 6a is an image showing the shape memory alloy wire used in Example 4 of the present invention, Figure 6b is a graph measuring the exothermic temperature according to the voltage applied to the shape memory alloy wire according to Example 4 of the present invention.
Figure 7a is an image showing the shape memory alloy wire used in Example 5 of the present invention, Figure 7b is a graph measuring the exothermic temperature according to the voltage applied to the shape memory alloy wire according to Example 5 of the present invention.
8A is an image showing the shape memory composite sheet bent according to Example 6 of the present invention, and FIG. 8B is an image showing the shape memory composite sheet restored according to Example 6 of the present invention.
9 is a perspective view illustrating a variable display device according to a first embodiment of the present invention;
10A and 10B are perspective views illustrating a variable display device according to a second embodiment of the present invention;
11 is a perspective view illustrating a variable display device according to a third embodiment of the present invention;
12 is an image illustrating shape deformation driving of the variable display device manufactured according to the first embodiment of the present invention;

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The shape memory material disclosed in the embodiment of the present invention may use a shape memory alloy (SMA) or a shape memory polymer (SMP). A shape memory alloy refers to an alloy that has a property of returning to its original shape when it becomes above the transition temperature even if it deforms below the transition temperature among various metal alloys. The transition temperature refers to the intrinsic constant temperature of a material when the state of the material is transitioned. For example, the shape memory alloy is formed to memorize a deformed shape, maintains a flat shape, and is configured to deform into a curved shape when heat is applied to reach a certain temperature or higher.

1 is a diagram schematically illustrating a driving principle of a shape memory alloy according to an embodiment of the present invention. Referring to the driving principle of the shape memory alloy with reference to FIG. 1 , the shape memory alloy has an austenite structure in a memory state that remembers a flat or curved shape. When the shape memory alloy is cooled, it is transformed into a martensite structure of a random state, and when heated again, it returns to the original austenite structure and returns to the shape of the original memory state. That is, when heat is applied after deformation occurs, it has a shape memory effect due to thermoelastic martensitic transformation that returns to an original shape.

On the other hand, the shape memory polymer is formed in a form in which various phases such as a stationary (hard) phase and a reversible (soft) phase exist together, and the stationary phase acts as a thermally stable crosslinking point. In general, a 'crosslinking point' may be a crystal, a glassy phase, or an entangled polymer chain that prevents the free movement of at least one part of the material. On the other hand, the reversible phase is a major part of shape memory polymers and plays an elastic role in deformation or recovery. Above a certain temperature, the reversible phase becomes a 'fluid' and has the property of being able to move freely. Conversely, below a certain temperature, the reversible phase may form a glassy or crystalline structure. This constant temperature is generally called a triggered temperature and corresponds to a glass transition temperature (Tg) or a melting point (Tm). When a strain is applied to the shape memory polymer, such as pulling at a temperature higher than the induced temperature, the polymer chains of the specimen are aligned, which in turn leads to a decrease in structural entropy. This state can be referred to as an entropy unstable or unfavorable state. This alignment can be maintained by rapidly cooling to the induced temperature in the strained state, except for the fine recovery performance.

Looking at the shape restoration process of the shape memory polymer, first, a specific deformation is applied to the shape memory polymer material, which exhibits elastic rubber properties at a temperature (Td) higher than the transition temperature (T trans), to give a change. At this time, the polymer chains are aligned according to the deformation. When a force capable of sustaining deformation is continuously applied and the material is cooled below the transition temperature (Tf < Ttrans) at which the material can be hardened, the chains constituting the polymer become immobile and change in the form of potential deformation energy and become fixed. remain in the state When the force given at the transition temperature is removed, a slight temporary recovery occurs. Shape recovery generally occurs without any external force by heating the temperature above the transition temperature, and the stored strain energy is released by allowing the polymer chain to move again.

The present invention discloses a shape-memory composite including a shape-memory material having the above-described properties. A more detailed look at the shape memory composite of the present invention is as follows.

2 is a diagram illustrating a shape memory composite according to an embodiment of the present invention. Referring to FIG. 2 , the shape memory composite 100 according to an embodiment of the present invention supplies heat including a shape memory layer 110 , an insulating layer 120 , a planar heating layer 132 and an electrode layer 134 . It includes a layer 130 , a protective layer 140 , and a heat diffusion layer 150 .

In more detail, the shape memory layer 110 serves as a core of the shape memory composite 100 and is a substantially deformable layer made of shape memory materials that is bent or stretched by heat. The shape memory layer 110 is formed in a sheet shape and is bent or flattened by heat transferred from the heat supply layer 130 . The shape memory layer 110 is made of shape memory materials, for example, a shape memory alloy or a shape memory polymer. Shape memory alloys can be classified into nickel-based (Ni), copper-based (Cu), iron-based (Fe), and the like, and include metals such as zinc (Zn), aluminum (Al), gold (Au), and silver (Ag). The combined Cu-Zn-Ni, Cu-Al-Ni, Ag-Ni, Au-Cd, etc. may be made of at least one selected from among dozens of alloys. The shape memory polymer may be made of at least one selected from polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, ethylene propylene rubber, chloroprene rubber, styrene butadiene rubber, nitrile butadiene rubber, and Teflon.

The insulating layer 120 is positioned on the shape memory layer 110 . The insulating layer 120 insulates the heat supply layer 130 and the shape memory layer 110 and is made of an organic material, an inorganic material, or an organic-inorganic hybrid material. For example, the insulating layer 120 is polycarbonate (PC), polyethylene terephthalate (PET), polyimide (poly imide, PI), polyethylstyrene (poly ether sulfone, PES) An organic material such as an organic material, an inorganic material such as silicon oxide (SiOx) or silicon nitride (SiNx), silica, and a low-k metal-based material may be formed of an organic-inorganic hybrid material mixed with an organic material.

The heat supply layer 130 is positioned on the insulating layer 120 . The heat supply layer 130 includes a planar heating layer 132 adjacent to the insulating layer 120 and an electrode layer 134 positioned on the planar heating layer 132 . The planar heating layer 132 is a layer that generates heat by acting as a resistance by the current applied from both electrodes of the electrode layer 134, and is made of a conductive material. The planar heating layer 132 may be made of, for example, a conductive material such as indium tin oxide (ITO), carbon nano tube (CNT), graphene, or graphite. However, the present invention is not limited thereto, and any material capable of generating resistance heat by an applied current is applicable. The electrode layer 134 is composed of a positive electrode and a negative electrode respectively positioned on one side and the other side of the planar heating layer 132 . For example, when the positive electrode is positioned on one side of the planar heating layer 132 in a line shape, the negative electrode is positioned on the other side facing it in a line shape. The electrode layer 134 is made of a metal such as copper (Cu), silver (Ag), or gold (Au) having excellent electrical conductivity and low resistance, and these metals may be applied in the form of a paste. Accordingly, a current flows between the positive electrode and the negative electrode, and the planar heating layer 132, which is a conductor through which the current flows, generates heat according to its resistance. Accordingly, the heat generated in the planar heating layer 132 is transferred to the shape memory layer 110 through the insulating layer 120 to deform the shape of the shape memory layer 110 .

A passivation layer 140 is positioned on the heat supply layer 130 . The protective layer 140 is to protect the components of the shape memory composite 100 , and is made of an organic material such as polycarbonate, polyethylene terephthalate, polyimide, or polyethylene styrene.

Meanwhile, the heat diffusion layer 150 is positioned under the shape memory layer 110 . The heat diffusion layer 150 serves to dissipate heat so that the heat of the shape memory layer 110 is easily discharged. Accordingly, the heat diffusion layer 150 is positioned to contact the entire lower surface of the shape memory layer 110 so that heat conduction of the shape memory layer 110 is good, and is made of a material having excellent thermal conductivity. For example, the heat diffusion layer 150 may be made of carbon nanotubes (CNT), graphite, aluminum (Al), copper (Cu), tungsten (W), or the like.

As described above, the shape memory composite 100 of the present invention includes a heat diffusion layer 150 , a shape memory layer 110 , an insulating layer 120 , a heat supply layer 130 , and a protective layer 140 from the bottom. do. That is, the shape memory composite 100 has the shape memory layer 110 as a core and the heat diffusion layer 150 , the insulating layer 120 , the heat supply layer 130 , and the protective layer 140 are multi-shell ) as a wrapper structure. In addition, the thickness of the shape memory composite 100 is made of 0.1 mm to 1 mm. Here, when the thickness of the shape-memory composite 100 is 0.1 mm or more, the sheet resistance is increased to improve heat generation characteristics, and when the thickness of the shape-memory composite 100 is 1 mm or less, it is possible to prevent an increase in the thickness of the display device. There are advantages that can be

Hereinafter, the shape memory layer of the shape memory composite of the present invention will be described in detail in the following experimental examples. However, the following experimental examples are merely illustrative of the present invention, and the present invention is not limited to the following experimental examples.

<Example 1>

Nitinol (NiTi) having a size of 0.5 mm in diameter and 100 mm in length was prepared as a shape memory alloy wire. (FIG. 3a) By measuring the exothermic temperature according to the voltage applied to the shape memory alloy wire, in the graph of Table 1 and FIG. 3B indicated. Here, the temperature was measured using a thermal imaging camera, and the resistance of nitinol was 1.2 Ω.

time (seconds)
Voltage (V) 4 5 6 7 8 9 10 5 23 23 23.5 24 26.5 29 33 10 23 23.2 23.9 24.5 27 31 36.3 15 23 23.4 24.2 25.6 27.6 32.2 38 20 23 23.4 24.5 27.1 28.6 33.2 38.5 30 23 23.5 25.5 28 29.8 34.2 39.3

Referring to Table 1 and FIG. 3B , the nitinol shape memory alloy wire having a diameter of 0.5 mm and a length of 100 mm exhibited an exothermic temperature of 23 to 39.3 degrees when a voltage of 4 to 10V was applied.

<Example 2>

Under the same conditions as in Example 1 described above, only the shape memory alloy wire (FIG. 4a) was prepared using nitinol having a diameter of 1 mm and a length of 100 mm. The heating temperature according to the voltage applied to the shape memory alloy wire was measured and shown in Table 2 and the graph of FIG. 4B. At this time, the resistance of nitinol was 0.9Ω.

time (seconds)
Voltage (V) 4 5 6 7 8 9 10 5 23 23 23 23.3 24 28.1 31 10 23 23.2 23.2 23.8 24.3 29.8 33.9 15 23 23.4 23.4 24.1 24.9 30.5 35 20 23 23.4 23.4 24.3 25.1 31.2 35.6 30 23 23.5 23.5 24.3 25.5 32 35.5

Referring to Table 2 and FIG. 4B , the nitinol shape memory alloy wire having a diameter of 1 mm and a length of 100 mm exhibited an exothermic temperature of 23 to 35.6 degrees when a voltage of 4 to 10V was applied.

<Example 3>

Under the same conditions as in Example 1 described above, only the shape memory alloy wire (FIG. 5a) was prepared using nitinol having a diameter of 3 mm and a length of 100 mm. The heating temperature according to the voltage applied to the shape memory alloy wire was measured and shown in Table 3 and the graph of FIG. 5B. At this time, the resistance of nitinol was 0.07Ω.

time (seconds)
Voltage (V) 4 5 6 7 8 9 10 5 23 23 23 23 23 23 23 10 23 23.1 23.2 23.2 23.2 23.2 23.2 15 23 23.1 23.4 23.4 23.4 23.4 23.4 20 23 23.2 23.4 23.4 23.4 23.4 23.4 30 23 23.3 23.5 23.5 23.5 23.5 23.5

Referring to Table 3 and FIG. 5B , the nitinol shape memory alloy wire having a diameter of 3 mm and a length of 100 mm exhibited an exothermic temperature of 23 to 23.5 degrees when a voltage of 4 to 10V was applied.

<Example 4>

Under the same conditions as in Example 1 described above, only a nitinol shape memory alloy wire ( FIG. 6A ) having a size of 10 mm in width, 100 mm in length and 0.5 mm in thickness was prepared. The heating temperature according to the voltage applied to the shape memory alloy wire was measured and shown in Table 4 and the graph of FIG. 6B. At this time, the resistance of nitinol was 0.07Ω.

time (seconds)
Voltage (V) 4 5 6 7 8 9 10 5 23 23 23 23 23 23 23 10 23 23.1 23.2 23.2 23.2 23.2 23.2 15 23 23.1 23.4 23.4 23.4 23.4 23.4 20 23 23.2 23.4 23.4 23.4 23.4 23.4 30 23 23.3 23.5 23.5 23.5 23.5 23.5

Referring to Table 4 and Figure 6b, the nitinol shape memory alloy wire having a size of 10mm in width, 100mm in length, and 0.5mm in thickness exhibited an exothermic temperature of 23 to 23.5 degrees when a voltage of 4 to 10V was applied.

<Example 5>

Under the same conditions as in Example 1 described above, only a shape memory composite sheet ( FIG. 7A ) having a size of 10 mm in width, 100 mm in length and 0.5 mm in thickness was prepared. The exothermic temperature according to the voltage applied to the shape memory composite sheet was measured and shown in Table 5 and the graph of FIG. 7B . At this time, the resistance of the shape memory composite was 20Ω.

time (seconds)
Voltage (V) 4 5 6 7 8 5 28 28.3 31.6 32.7 35.8 10 29.8 30.2 33.4 36.5 39 20 31.1 33.1 34.3 39.4 42.6 30 31.9 35 38.6 41.3 48.5 40 33.5 37.6 41.6 42.7 55 50 35 38.8 44 51 65 60 35.8 39.5 46.9 54.3 70.9

Referring to Table 5 and FIG. 7B , the shape memory composite sheet having a size of 10 mm in width, 100 mm in length, and 0.5 mm in thickness exhibited an exothermic temperature of 28 to 70.9 degrees when a voltage of 4 to 10V was applied.

<Example 6>

A shape memory composite sheet having a size of 10 mm in width, 100 mm in length, and 0.5 mm in thickness described in Example 5 was prepared. As shown in FIG. 8A , the shape memory composite sheet was bent to a curvature of 100R before voltage application. Then, a voltage was applied to the shape memory composite sheet, and the time required for flat restoration as shown in FIG. 8B according to the applied voltage was measured and shown in Table 6 below. In Sample #1, the shape memory layer had a heat deformation temperature of 70 degrees, and in Sample #2, the shape memory layer had a heat deformation temperature of 50 degrees.

Voltage (V)/Sample #One #2 4 - - 5 - - 6 120 seconds 60 seconds 7 65 seconds 45 seconds 8 60 seconds 40 seconds

Referring to Table 6, the shape memory complex of Sample #1 took 120 seconds to fully recover at 6V, but took 60 seconds at 8V. In addition, the shape memory complex of Sample #2 took 60 seconds to fully recover at 6V, but took 40 seconds at 8V.

Through the above-described Examples 1 to 5, the shape memory composite sheet of the present invention exhibits a heating temperature of about 70 degrees in the range of 4 to 8 V, which is a voltage applicable to a mobile device. Therefore, as shown in Example 6, the shape memory composite showed a complete recovery time of as long as 120 seconds and as short as 40 seconds, proving that the shape memory composite of the present invention is applicable to mobile.

Hereinafter, the variable display device including the shape memory composite according to the embodiment of the present invention described above will be described.

9 is a perspective view showing a variable display device according to a first embodiment of the present invention, FIGS. 10A and 10B are perspective views illustrating a variable display device according to a second embodiment of the present invention, and FIG. 11 is a first embodiment of the present invention. A perspective view showing a variable display device according to a third embodiment, and FIG. 12 is a photograph showing shape deformation driving of the variable display device manufactured according to the first embodiment of the present invention.

Referring to FIG. 9 , in the variable display device 200 according to the first embodiment of the present invention, an organic light emitting diode panel 220 is positioned on a main frame 210 and a cover is provided on the organic light emitting diode panel 220 . 230 is provided. A washer 240 is positioned at one lower side of the main frame 210 to prevent heat from the shape memory composite 250 from being transferred to the main frame 210 . At least one shape memory composite 250 is disposed adjacent to the washer 240 . The shape memory composite 250 includes two types of shape memory composites 250 that bend when heat is applied and become flat when cooled, and become flat when heat is applied and bend when cooled. A stopper 260 is positioned adjacent to the shape memory composite 250 to maintain a curved or flat state of the display device. A rear cover 280 is provided under the main frame 210 , and the variable display device 200 is configured by combining the cover 230 , the main frame 210 , and the rear cover 280 .

Such a variable display device 200 drives the shape-memory composite 250, which is bent when heat is applied, to cause the display device to be bent. When the display device is bent, the stoppers 260 are engaged with each other to maintain the bent state. Accordingly, the display device maintains a curved state even if the shape memory composite 250 is not driven. Conversely, when the display device is flattened again, when the shape memory composite 250 that is flattened when heat is applied is driven, the interlocked stopper 260 is released, so that the display device becomes flat.

In the above-described variable display device 200 according to the first embodiment of the present invention, the shape memory complex 250 is provided on the rear surface of the main frame 210 , and the display device is fixed by a stopper 260 , so that the shape memory A variable display device in which the display device is curved or flat can be implemented by the composite 250 .

Meanwhile, the variable display device 200 according to the second embodiment of the present invention will be described with reference to FIGS. 10A and 10B . Hereinafter, the same reference numerals are given to the same components as those of the above-described first embodiment, and overlapping descriptions will be omitted.

Referring to FIG. 10A , in the variable display device 200 according to the second embodiment of the present invention, a cover 230 and an organic light emitting diode panel (not shown) are positioned on a main frame 210 , and a main frame 210 is provided. ), the shape memory composite 250 and the fixing part 300 are provided on the rear surface. The cover 230 and the main frame 210 are coupled to the rear cover 270 to constitute a display device. The shape memory composite 250 includes a first shape memory composite 252 that is bent when heat is applied and a second shape memory composite 254 that becomes flat when heat is applied. Referring to FIG. 10B , the fixing unit 300 provided in the variable display device 200 according to the second embodiment includes a spring 320 fixed to the support unit 310 and a ball 330 provided at the end of the spring 320 ( ball) is provided. The support part 310 is configured to be movable left and right according to the bending of the display device. As the support 310 moves, the spring 320 and the ball 330 fixed to the support 310 move together.

Such a variable display device 200 drives the first shape memory composite 252, which is bent when heat is applied, to cause the display device to be bent. When the display device is bent, the fixing part 300 is moved from the first groove 340 to the second groove 350 by the bending force and is fixed. In more detail, as the spring 320 is reduced, the support 310 is moved from the first groove 340 to the second groove 350 . At this time, the ball 320 is detached from the first hole 340 and moved to the second hole 350 , and the ball 320 reaches the second hole 350 and is coupled thereto. Accordingly, when the fixing part 300 is coupled to the second groove 350 , the display device maintains a curved state even if the shape memory composite 250 is not driven. Conversely, when the display device is flattened again, if the second shape memory composite 254 that becomes flat when heat is applied is driven, the fixing part 300 is moved back to the first groove 340 to be coupled to the flat display device. will keep

In the above-described variable display device 200 according to the second embodiment of the present invention, the shape memory complex 250 is provided on the rear surface of the main frame 210 , and the display device is fixed by the ball-type fixing unit 300 . By doing so, a variable display device in which the display device is curved or flat by the shape memory composite 250 may be implemented.

Meanwhile, with reference to FIG. 11 , the variable display device 200 according to the third embodiment of the present invention will be described as follows. Hereinafter, the same reference numerals are assigned to the same components as those of the above-described first and second embodiments, and overlapping descriptions will be omitted.

Referring to FIG. 11 , in the variable display device 200 according to the third exemplary embodiment of the present invention, a cover 230 and an organic light emitting diode panel (not shown) are positioned on a main frame 210 , and a main frame 210 is provided. ), the shape memory complex 250 is provided on the rear surface. The shape memory composite 250 includes a first shape memory composite 252 that is bent when heat is applied and a second shape memory composite 254 that becomes flat when heat is applied. The cover 230 and the main frame 210 are coupled to the rear cover 270 to configure the display device. In particular, in the third embodiment of the present invention, the adjustment pin 400 , the slide plate 410 , and the adjustment cam 420 are provided on the upper side of the main frame 210 to maintain the curved or flat shape of the display device.

In more detail, in the variable display device 200 of the third embodiment, the slide plate 410 is positioned above the main frame 210 . The slide plate 410 is moved downward or upward according to the bending of the display device to maintain the shape of the display device. Adjusting pins 400 are positioned at both edges of the upper side of the slide plate 410 to control the moving speed when the slide plate 410 moves downward or moves upward. Adjustment cams 420 are positioned on both sides of the slide plate 410 to fix the slide plate 410 . The adjustment pin 400 and the adjustment cam 420 are respectively provided with springs 405 and 425 to support the adjustment pin 400 and the adjustment cam 420 .

Such a variable display device 200 drives the first shape memory composite 252, which is bent when heat is applied, to cause the display device to be bent. When the display device is bent, the slide plate 410 is moved downward by the bending force. In more detail, when the display device is bent, the slide plate 410 is moved downward by the bending force and the spring 405 of the adjustment pin 400 is stretched to push the slide plate 410 . When the slide plate 410 starts to move, the spring 425 of the adjustment cam 420 is reduced and the slide plate 410 is unfixed and the slide plate 410 is moved. When the bending of the display device is maximized, that is, when the slide plate 410 is completely moved downward, the spring 425 of the adjustment cam 420 is extended and the adjustment cam 420 fixes the slide plate 410 . . Accordingly, the display device maintains a curved state even if the shape memory composite 250 is not driven. Conversely, when the display device is flattened again, if the second shape memory complex 254, which becomes flat when heat is applied, is driven, the spring 425 of the adjustment cam 420 is reduced, and the fixing of the slide plate 410 is released. do. Accordingly, the slide plate 410 is moved upward. At this time, as the spring 405 of the adjustment pin 400 is gradually reduced, the shape of the display device is gradually deformed. When the movement of the slide plate 410 is completely finished, the spring 425 of the adjustment cam 420 is extended to fix the slide plate 410, thereby maintaining a flat display device.

In the above-described variable display device 200 according to the third embodiment of the present invention, the shape memory composite 250 is provided on the rear surface of the main frame 210 , and the display device is fixed in a slide type, so that the shape memory composite 250 is provided. ), it is possible to realize a variable display device in which the display device is curved or flat.

As described above, the shape memory composite and the variable display device including the same according to the embodiments of the present invention have the advantage of reducing the variable driving time of the variable display device by improving the driving force and reactivity of the shape memory composite. In addition, there is an advantage in that a curved or flat shape can be maintained without driving the shape memory composite by providing various fixing members in the variable display device including the shape memory composite.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention can be changed to other specific forms by those skilled in the art to which the present invention pertains without changing the technical spirit or essential features of the present invention. It will be appreciated that this may be practiced. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. In addition, the scope of the present invention is indicated by the claims to be described later rather than the above detailed description. In addition, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention.

100: shape memory complex 110: shape memory layer
120: insulating layer 130: heat supply layer
140: protective layer 150: heat diffusion layer

Claims (12)

delete delete delete delete main frame;
a display panel positioned on the main frame;
a cover positioned on the display panel;
at least one shape memory complex positioned under the main frame;
and a rear cover coupled to the cover to accommodate the display panel, the main frame, and the shape memory composite,
The shape memory complex,
a first shape memory composite that is bent when heated and flattened when cooled; and
a second shape memory composite that flattens when heated and bends when cooled;
Each of the first and second shape memory complexes,
a shape memory layer, an insulating layer positioned on the shape memory layer, a heat supply layer positioned on the insulating layer, a protective layer positioned on the heat supply layer, and a heat diffusion layer positioned below the shape memory layer and
and a structure in which the heat diffusion layer, the insulating layer, the heat supply layer, and the protective layer are surrounded as a multi-shell with the shape memory layer as a core.
6. The method of claim 5,
a washer disposed on a lower side of the main frame; and
Further comprising a stopper positioned adjacent to the shape memory composite under the main frame,
The washer prevents the heat of the shape memory composite from being transferred to the main frame,
The stopper is fixed to each other by a force that bends or unfolds the shape memory composite, thereby maintaining the shape of the variable display device.
6. The method of claim 5,
Further comprising a fixing part,
The fixing part includes a support part, a spring fixed to the support part, and a ball provided at an end of the spring,
The variable display device according to claim 1, wherein the fixing part is a means for maintaining the shape of the variable display device by moving and fixing the ball by the force of bending or unfolding the shape memory composite.
6. The method of claim 5,
Further comprising a slide plate located under the main frame,
The slide plate includes an adjustment pin positioned at both upper corners to adjust a moving speed when the slide plate moves upward or downward, and an adjustment cam for fixing the slide plate,
The slide plate is a means for maintaining the shape of the variable display device by moving and fixing the shape memory composite by a bending or unfolding force.
6. The method of claim 5,
The shape memory layer is a variable display device, characterized in that made of a sheet shape.
6. The method of claim 5,
The heat supply layer includes a planar heating layer and electrodes positioned on both sides of the planar heating layer.
6. The method of claim 5,
The shape memory composite has a thickness of 0.1 mm to 1 mm.
12. The method according to any one of claims 5 to 11,
The shape memory layer is Cu-Zn in which metals such as nickel-based (Ni), copper-based (Cu), iron-based (Fe), zinc (Zn), aluminum (Al), gold (Au), and silver (Ag) are combined. -Ni, Cu-Al-Ni, Ag-Ni, at least one selected from the alloy system of Au-Cd, or polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, ethylene propylene rubber, chloroprene rubber, styrene butadiene rubber, nitrile Variable display device comprising at least one selected from butadiene rubber and Teflon

Images