KR102325014B1 - Flexible display device - Google Patents

Abstract

An embodiment of the present invention relates to a flexible display device that can be changed into two or more shapes by implementing the flexible display panel to have bistability for stably maintaining two or more shapes. A flexible display device according to an embodiment of the present invention includes a lower substrate, a plastic film, and first and second shape change means. The lower substrate is made of a bistable material stably maintaining at least two types of shapes. The plastic substrate is disposed on the lower substrate, and a pixel array is formed. The first shape changing means is disposed on one surface of the lower substrate to deform the lower substrate to a first stable state. The second shape changing means is disposed on the opposite surface of the one surface of the lower substrate to deform to the second stable state.

Description

Flexible display device {FLEXIBLE DISPLAY DEVICE}

An embodiment of the present invention relates to a flexible display device.

Recently, various display devices capable of reducing weight and volume, which are disadvantages of a cathode ray tube, have been developed. Examples of such display devices include a liquid crystal display, a field emission display, a plasma display panel, and an organic light emitting display. In particular, among display devices, a liquid crystal display device and an organic light emitting display device are being developed as flexible display devices having flexibility.

The flexible display device includes a flexible display panel. The flexible display panel may be implemented as a liquid crystal display panel and an organic light emitting display panel. In order to increase the flexibility of the flexible display panel, a plastic substrate such as a polyimide film is used as a substrate of the flexible display panel. In this case, it is difficult for the flexible display panel to be consistently maintained in any shape due to its flexibility. Therefore, the flexible display panel further includes a support substrate for supporting the flexible display panel.

However, since the support substrate has to maintain the display panel in a certain shape, flexibility is lower than that of the flexible display panel. As a result, since the flexible display panel is attached to a support substrate having low flexibility despite being implemented as flexible, there is a limitation in the variability of the flexible display device.

An embodiment of the present invention provides a flexible display device that can be changed into two or more shapes by implementing the flexible display panel to have bistability for stably maintaining two or more shapes.

A flexible display device according to an embodiment of the present invention includes a lower substrate, a plastic film, and first and second shape change means. The lower substrate is made of a bistable material stably maintaining at least two types of shapes. The plastic substrate is disposed on the lower substrate, and a pixel array is formed. The first shape changing means is disposed on one surface of the lower substrate to deform the lower substrate to a first stable state. The second shape changing means is disposed on the opposite surface of the one surface of the lower substrate to deform to the second stable state.

In an embodiment of the present invention, the lower substrate is made of a material having bistability to stably maintain at least two shapes. As a result, according to an embodiment of the present invention, the flexible display device can be implemented to have at least two types, and the user can deform the flexible display device by directly applying force to the lower substrate.

In addition, in the embodiment of the present invention, the lower substrate may be deformed from the second stable state to the first stable state by using the first shape changing means, and the lower substrate may be changed from the first stable state by using the second shape changing means. It can be transformed into a second stable state. As a result, according to the embodiment of the present invention, the lower substrate can be deformed by the first and second shape changing means even if the user does not directly apply force.

1A and 1B are perspective views illustrating a flexible display device according to a first embodiment of the present invention;
FIG. 2 is an exploded perspective view of the flexible display device of FIG. 1A;
3 is a cross-sectional view of a flexible display panel;
4A and 4B are perspective views illustrating an example of the lower substrate of FIGS. 1A and 1B and first and second shape changing means;
5 is an exemplary view showing that a lower substrate is deformed from a first stable state to a second stable state by a bend propagation action;
6A and 6B are perspective views showing still another example of a lower substrate and first and second shape changing means;
7A and 7B are perspective views illustrating still another example of the lower substrate of FIGS. 1A and 1B and first and second shape changing means;
8A and 8B are perspective views illustrating still another example of the lower substrate of FIGS. 1A and 1B and first and second shape changing means;
9A and 9B are perspective views illustrating a flexible display device according to a second exemplary embodiment of the present invention;
10 is an exploded perspective view of the flexible display device of FIG. 9A;
11A and 11B are perspective views illustrating a flexible display device according to a third exemplary embodiment of the present invention;
12 is an exploded perspective view of the flexible display device of FIG. 11A;
13A and 13B are perspective views illustrating an example of the lower substrate of FIGS. 7A and 7B and first and second shape changing means;
Fig. 14 is an exploded perspective view showing the first shape changing means in detail;
15A and 15B are perspective views illustrating a flexible display device according to a fourth embodiment of the present invention;
16 is an exploded perspective view of the flexible display device of FIG. 15A;

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, and thus the present invention is not limited to the illustrated matters. Like reference numerals refer to like elements throughout. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the case in which the plural is included is included unless otherwise explicitly stated.

In interpreting the components, it is interpreted as including an error range even if there is no separate explicit description.

In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' Alternatively, one or more other parts may be positioned between the two parts unless 'directly' is used.

In the case of a description of a temporal relationship, for example, 'immediately' or 'directly' when a temporal relationship is described with 'after', 'following', 'after', 'before', etc. It may include cases that are not continuous unless this is used.

Although the first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the spirit of the present invention.

"X-axis direction", "Y-axis direction" and "Z-axis direction" should not be construed only as a geometric relationship in which the relationship between each other is vertical, and is wider than within the range where the configuration of the present invention can function functionally. It may mean having a direction.

The term “at least one” should be understood to include all possible combinations from one or more related items. For example, the meaning of "at least one of the first, second, and third items" means 2 of the first, second, and third items as well as each of the first, second, or third items. It may mean a combination of all items that can be presented from more than one.

Each feature of the various embodiments of the present invention may be partially or wholly combined or combined with each other, technically various interlocking and driving are possible, and each of the embodiments may be implemented independently of each other or may be implemented together in a related relationship. may be

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

1A and 1B are perspective views illustrating a flexible display device according to a first exemplary embodiment of the present invention. FIG. 2 is an exploded perspective view of the flexible display device of FIG. 1A . 1A, 1B, and 2 , the flexible display device FDIS according to the first embodiment of the present invention includes a flexible display panel 100 , a transparent adhesive layer 300 , a touch panel 400 , and a polarizing plate. (500). In the case of an in-cell method in which the touch sensors are formed in the flexible display panel 100 , the touch panel 400 may be omitted.

The flexible display panel 100 includes a lower substrate 110 , a plastic film 120 , an upper substrate 130 , a driving integrated circuit (hereinafter referred to as “IC”, 150 ), a flexible film 150 , and a circuit board. 160 , a timing control circuit 170 , first and second shape changing means 210 and 220 , and a shape changing means driving unit 230 .

The lower substrate 110 is a substrate for supporting the flexible display panel 100 in a predetermined shape. The lower substrate 110 may be made of a material having bistability capable of stably maintaining at least two shapes. That is, the object generally has a single stable state that stably maintains one shape, but the lower substrate 110 according to the first embodiment of the present invention has a bistable state that can stably maintain at least two shapes. state) or have multiple stable states.

For example, the lower substrate 110 may have a first stable state curved in a "∪" shape in the short side direction as shown in FIG. 1A and a second stable state curved in a "∩" shape in the long side direction as shown in FIG. 1B . have. Alternatively, the lower substrate 110 may have a first stable state that is straight without being bent or bent and a second stable state that is curved in a “∪” shape in the short side direction or is curved in a “∩” shape in the long side direction. That is, since only some of the shapes that the lower substrate 110 may have are exemplified in FIGS. 1A and 1B , the shape of the lower substrate 110 in the first stable state and the shape of the lower substrate 110 in the second stable state are illustrated. is not limited to that shown in FIGS. 1A and 1B .

In addition, since the flexible display panel 100 has flexibility to be bent or bent, the flexible display device has a first stable shape curved in the short side direction as shown in FIG. 1A according to the deformation of the lower substrate 110 . It may have a state and a second stable state curved in the shape of “∩” in the long side direction as shown in FIG. 1B .

The lower substrate 110 may be made of a metal such as beryllium copper alloy, aluminum, or stainless steel to maintain a bistable state. For example, in order to remove the stress of the beryllium copper alloy, it should be heated at approximately 148°C to 204°C for 2 hours or more. Therefore, considering the temperature during the manufacturing process of the flexible display panel 100 , the stress of the beryllium copper alloy is not removed even through the manufacturing process of the flexible display panel 100 . Accordingly, the lower substrate 100 may have a bistable state. On the other hand, the lower substrate 110 may be made of carbon fiber reinforced plastic, but in this case, there is a high possibility that the lower substrate 100 will be damaged by the temperature of the manufacturing process of the flexible display panel 100, Due to this, the lower substrate 100 may not have a bistable state. Therefore, the lower substrate 110 is preferably made of a material capable of maintaining a bistable state, for example, a beryllium copper alloy, even though the lower substrate 110 undergoes a manufacturing process of the flexible display panel 100 rather than carbon fiber reinforced plastic. do.

Since the lower substrate 110 is a conductive metal material, a plastic substrate 120 is disposed on the lower substrate 110 to form signal lines of the pixel array. The plastic substrate 120 may be bent or bent, and may be formed of a material having high restoring force. For example, the plastic substrate 120 may be formed of any one of polyimide, polyethylene terephthalate, polyethylene naphthalate (PEN), polycarbonate, and polyester sulfone (PES). and it should be noted that the present invention is not limited thereto.

The flexible display panel 100 may be implemented as an organic light emitting display as shown in FIG. 3 , but is not limited thereto, and may be implemented as a liquid crystal display. Hereinafter, the flexible display panel 100 will be mainly described as an organic light emitting display device as shown in FIG. 3 .

A buffer layer BF may be formed on the plastic substrate 120 . The buffer layer BF may be formed of a multilayered inorganic layer or a multilayered inorganic layer, a composite layer of an organic layer, and an inorganic layer. For example, the buffer layer BF may include _{at least one of a silicon oxide layer (SiO 2} ) and a silicon nitride layer (SiNx). The buffer layer BF may be formed by an inorganic film deposition process and/or an organic film deposition process.

On the buffer layer BF of the plastic substrate 120 , the active layer ACT, the gate electrode GE connected to the gate line, the source electrode SE connected to the data line, and the drain electrode connected to the anode electrode AND A pixel array PA in which a thin film transistor T including DE is provided is formed. 3 illustrates that the thin film transistor T is formed in a top gate method, but is not limited thereto, and may be formed in a bottom gate method.

The active layer ACT is provided on the buffer layer BF, and the first gate insulating layer GI1 is provided on the buffer layer BF. The active layer ACT may be formed of a semiconductor material, and the first gate insulating layer GI1 _{is formed of a single layer of silicon oxide (SiO 2} ) or silicon nitride (SiNx), or silicon oxide (SiO ₂ ) and silicon nitride ( SiNx) as a composite film.

The gate electrode GE is provided on the first gate insulating layer GI1 , and the active layer ACT and the gate electrode GE are insulated by the first gate insulating layer GI1 . The gate electrode GE may be formed of any one of molybdenum (Mo), titanium (Ti), aluminum (Al), copper (Cu), and chromium (Cr) or an alloy thereof.

The second gate insulating layer GI2 is provided on the gate electrode GE, and the source electrode SE and the drain electrode DE are provided on the second gate insulating layer GI2. The gate electrode GE, the source electrode SE, and the drain electrode DE are insulated by the second gate insulating layer GI2. The source electrode SE is connected to the active layer ACT through the first contact hole CNT1 penetrating through the first and second gate insulating layers GI1 and GI2 to expose the active layer ACT. The drain electrode DE is connected to the active layer ACT through the second contact hole CNT2 through which the active layer ACT is discharged through the first and second gate insulating layers GI1 and GI2 . A second gate insulating film (GI2) may be formed of a composite film of a silicon oxide (SiO ₂₎ or silicon nitride (SiNx) is formed as a single film or a silicon oxide (SiO ₂₎ and silicon nitride (SiNx) of. The source electrode SE and the drain electrode DE may be formed of molybdenum (Mo) or a molybdenum alloy.

An interlayer insulating layer ILD is provided on the source electrode SE and the drain electrode DE. The interlayer insulating layer ILD may be formed of photo acryl (PAC).

An anode electrode AND is provided on the interlayer insulating layer ILD. The source electrode SE, the drain electrode DE, and the anode electrode AND are insulated by the interlayer insulating layer ILD. The anode electrode AND is connected to the drain electrode DE through the third contact hole CNT3 penetrating the interlayer insulating layer ILD and exposing the drain electrode DE. In a top emission structure as shown in FIG. 3 , the anode electrode AND may be formed of a metal material having a high reflectance, such as a stacked structure of aluminum and aluminum and ITO.

A partition wall W for partitioning a pixel area is provided between the anode electrode AND and the anode electrode AND adjacent thereto. The light emitting layer EL is provided on the anode electrode AND surrounded by the barrier rib W. As shown in FIG. The emission layer EL may include a hole transporting layer, an organic light emitting layer, and an electron transporting layer. A cathode electrode CAT is provided on the light emitting layer EL and the barrier rib W. The cathode electrode CAT may be formed of a transparent metal material such as ITO or IZO. When a voltage is applied to the anode electrode AND and the cathode electrode CAT, holes and electrons move to the organic light emitting layer through the hole transport layer and the electron transport layer, respectively, and combine with each other in the organic light emitting layer to emit light.

An organic/inorganic composite film OIC for protecting the light emitting layer EL and the cathode electrode CAT from oxygen and moisture is formed on the cathode electrode CAT. The organic-inorganic composite layer OIC may include a plurality of organic layers and at least one inorganic layer.

On the organic-inorganic composite layer OIC, the upper substrate 130 may be disposed on the organic-inorganic composite layer. Color filters and a black matrix may be formed on the upper substrate 130 . However, in the case of a colorfilter on tft array (COT) method in which the color filters and the black matrix are formed on the plastic substrate 120 , the color filters and the black matrix are not formed on the upper substrate 130 . The upper substrate 130 may also be bent or bent, may be formed of a material having high restoring force, and is preferably a plastic substrate. For example, the upper substrate 130 may be formed of any one of polyimide, polyethylene terephthalate, polyethylene naphthalate (PEN), polycarbonate, and polyester sulfone (PES). and it should be noted that the present invention is not limited thereto.

A gate driving circuit and a pad part may be further formed around the pixel array PA on the buffer layer of the plastic substrate 120 . The gate driving circuit is connected to the gate lines to supply gate signals. The gate driving circuit may be provided in the non-display area by a gate driver in panel (GIP) method. The pad part includes a plurality of pads, and may be provided on a buffer layer on one edge of the plastic substrate 120 . The pads may be connected to the data lines.

The flexible film 150 may be implemented as a chip on film on which the driving IC 140 is mounted as shown in FIGS. 1A and 1B . A plurality of wires connected to the driving IC 140 and a plurality of pads connected to the pads may be formed on the flexible film 150 .

The flexible film 150 may be attached to the pads. Specifically, an anisotropic conducting film for adhering the pads and the pads of the flexible film 150 may be provided between the pads and the flexible film 150 .

The driving IC 140 may be mounted on the flexible film 150 by a chip on plastic (COP) process. The driving IC 140 may output data voltages supplied to the data lines. In this case, the data voltages output from the driving IC 140 may be supplied to the data lines through the flexible film 150 and the pads.

The circuit board 170 is adhered to the flexible film 150 . A timing control circuit 160 for controlling driving timing of the gate driving circuit and the driving IC 140 may be mounted on the circuit board 170 . In addition, the circuit board 170 may be mounted with a shape changing means driving unit 230 for driving a shape changing means for controlling the shape change of the lower substrate 110 . The flexible film 150 and the circuit board 170 may be fixed by being folded to the opposite surface of one surface of the lower substrate 110 in order to minimize a bezel of the flexible display device.

The first shape changing means 210 is disposed on one surface of the lower substrate 110 on which the plastic substrate 120 is disposed. The second shape changing means 220 is disposed on the opposite surface of one surface of the lower substrate 110 as shown in FIGS. 4A, 4B, 6A, 6B, 7A, 7B, 8A, and 8B. do. One surface of the lower substrate 110 corresponds to a surface on which the plastic film 120 is disposed, that is, a surface facing the plastic film 120 .

The first and second shape changing means 210 and 220 are connected to the shape changing means driving unit 230 to receive voltage from the shape changing means driving unit 230 . The first shape changing means 210 may be contracted when a voltage is applied from the shape changing means driving unit 230 to deform the lower substrate 110 to a first stable state as shown in FIG. 1A . In addition, the second shape changing means 220 may be contracted when a voltage is applied from the shape changing means driving unit 230 to deform the lower substrate 110 to a second stable state as shown in FIG. 1B . Since the flexible display panel 100 has flexibility to be bent or bent, as the lower substrate 110 is deformed by the first and second shape changing means 210 and 220 , the flexible display panel 100 is can be deformed.

When the first and second shape changing means 210 and 220 are twisted shape memory alloys as shown in FIGS. 1A and 1B , they are preferably disposed so as not to overlap the pixel array PA. Since the shape memory alloy is changed by Joule's heat when current flows, the first and second shape changing means when each of the first and second shape changing means 210 and 220 is a shape memory alloy. When current flows through the fields 210 and 220, the shape is changed by Joule's heat. When the first and second shape changing means 210 and 220 are formed to overlap the pixel array PA, for example, the second shape changing means 220 is the lower substrate 110 on which the pixel array PA is formed. In the case of being formed on the opposite surface of one surface of the pixel array PA, the light emitting layer EL of the pixel array PA may be deteriorated due to the row rows of the second shape changing means 220 , and as a result, a luminance deviation within the pixel array PA may be reduced. can occur Accordingly, the first shape changing means 210 is disposed on the edge of one surface of the lower substrate 110 so as not to overlap the pixel array PA, and the second shape changing means 220 is arranged not to overlap the pixel array PA. It may be disposed on the edge of the opposite surface of the one surface of (110). For example, the first shape changing means 240 may be disposed on the edge of one surface of the lower substrate 110 not covered by the plastic film 120 .

A detailed description of the first and second shape changing means 210 and 220 will be described later in conjunction with FIGS. 4A, 4B, 6A, 6B, 7A, 7B, 8A and 8B.

The touch panel 400 may be disposed on the upper substrate 130 . The upper substrate 130 and the touch panel 400 may be bonded by the transparent adhesive layer 300 . The transparent adhesive layer 300 may be an optically clear resin layer (OCR) or an optically clear adhesive film (OCA).

The touch panel 400 may be implemented as any one of a capacitive type, a resistive type, a pressure type, an ultrasonic type, and an optical type touch panel. However, in the touch panel 400 according to the first embodiment of the present invention, a hover that detects not only a user's direct touch but also a user's finger or the like is located close to the touch panel 400 . It is preferable to be implemented in a capacitive method capable of sensing. Since the touch panel 400 may be implemented as any one of known touch panels, a detailed description thereof will be omitted.

The polarizing plate 500 may be disposed on the touch panel 400 to prevent image quality deterioration due to external light reflection.

Meanwhile, since the transparent adhesive layer 300 , the touch panel 400 , and the polarizing plate 500 are more flexible than the flexible display panel 100 , the flexible display device FIDS may be deformed according to the deformation of the flexible display panel 100 . .

As described above, in the first embodiment of the present invention, the lower substrate 110 is made of a material having bistability to stably maintain at least two shapes. As a result, according to the first embodiment of the present invention, the flexible display device FDIS may be implemented to have at least two types.

On the other hand, since the lower substrate 110 according to the first embodiment of the present invention is made of a material having bistability capable of stably maintaining at least two shapes, a user directly applies a force to the lower substrate 110 . ) can be transformed. However, in the first embodiment of the present invention, the lower substrate 110 may be deformed using the first and second shape changing means 210 and 220 even if the user does not directly apply force. Hereinafter, in conjunction with FIGS. 4A, 4B, 6A and 6B, 7A, 7B, 8A and 8B, the lower substrate 110 and the first and second shape changes according to embodiments of the present invention The means 210 and 220 will be described in detail.

4A and 4B are perspective views illustrating the lower substrate of FIGS. 1A and 1B and first and second shape changing means; In FIGS. 4A and 4B , only the lower substrate 110 and the first and second shape changing means 210 and 220 are illustrated for convenience of description.

4A and 4B , the first shape changing means 210 is disposed on the edge of one surface of the lower substrate 110 , and the second shape changing means 220 is disposed on the edge of the opposite surface of the lower substrate 110 . do. In FIGS. 4A and 4B , the second shape changing means 220 disposed on the opposite surface of the lower substrate 110 is not visible, so it is illustrated with a dotted line. In addition, the first shape changing means 210 may be disposed on one short side edge of the lower substrate 110 , and the second shape changing means 220 may be disposed on the other short side edge of the lower substrate 110 . On the other hand, the flexible film 150 and the circuit board 170 may be fixed by being folded from one short side edge to the opposite surface of one surface of the lower substrate 110 .

1A, 1B and 4A, and 4B illustrate that the first and second shape changing means 210 and 220 are twisted shape memory alloys. The shape memory alloy changes shape by Joule's heat when current flows. When the shape memory alloy is formed in a twisted shape, the shape memory alloy can be changed more rapidly than when the shape memory alloy is formed in a straight shape because the heat loss of the shape memory alloy is less. For this reason, when the shape memory alloy is formed in a twisted shape, it is possible to reduce power consumption for changing the shape of the shape memory alloy compared to when the shape memory alloy is formed in a straight shape.

When the first and second shape changing means 210 and 220 are formed to overlap the pixel array PA, the first and second shape changing means 210 and 220 are arranged in rows to change the shape of the pixel array PA. The light emitting layer EL may be deteriorated, which may cause a luminance deviation within the pixel array PA. Therefore, the first shape changing means 210 is disposed on one surface of the lower substrate 110 so as not to overlap the pixel array PA, and the second shape changing means 220 is disposed on the lower substrate 110 so as not to overlap the pixel array PA. 110) is disposed on the opposite side of the one side.

Since the first shape changing means 210 contracts as shown in FIG. 4A when a voltage is applied, the lower substrate 110 may be deformed from the second stable state to the first stable state. The first shape changing means 210 is disposed at the edge of one surface of the lower substrate 110 so as not to overlap the pixel array PA. In this case, the lower substrate 110 has a bend propagation action capable of changing the overall curvature of the lower substrate 110 by changing the shape of the edge of one surface of the lower substrate 110 by the first shape changing means 210 . can be transformed by actuation).

Since the second shape changing means 220 contracts as shown in FIG. 4B when a voltage is applied, the lower substrate 110 may be deformed from the first stable state to the second stable state. The second shape changing means 220 is disposed on the edge of the opposite surface of one surface of the lower substrate 110 so as not to overlap the pixel array PA. In this case, the lower substrate 110 may change the overall curvature of the lower substrate 110 by changing the shape of the edge of the opposite surface of the one surface of the lower substrate 110 by the second shape changing means 220 as shown in FIG. 5 . It can be deformed by bend propagation actuation.

As described above, in the first embodiment of the present invention, the first shape changing means 210 can be contracted to deform the lower substrate 110 from the second stable state to the first stable state, and for this purpose, the first A voltage is applied to the shape changing means 210 . In addition, in the first embodiment of the present invention, the second shape changing means 220 can be contracted to deform the lower substrate 110 from the first stable state to the second stable state, and for this purpose, the second shape changing means ( 220) is applied. As a result, in the first embodiment of the present invention, the lower substrate 110 may be deformed by the first and second shape changing means 210 and 220 even if the user does not directly apply force.

6A and 6B are perspective views illustrating still another example of a lower substrate and first and second shape changing means. In FIGS. 6A and 6B , only the lower substrate 110 and the first and second shape changing means 210 and 220 are illustrated for convenience of description.

As described with reference to FIGS. 4A and 4B except that the first and second shape changing means 210 and 220 shown in FIGS. 6A and 6B are disposed on one short edge of the lower substrate 110 . Practically the same. On the other hand, the flexible film 150 and the circuit board 170 may be fixed by being folded from one short side edge or the other short side edge to the opposite surface of the one surface of the lower substrate 110 .

7A and 7B are perspective views illustrating still another example of a lower substrate and first and second shape changing means. In FIGS. 7A and 7B , only the lower substrate 110 and the first and second shape changing means 210 and 220 are illustrated for convenience of description.

The first shape changing means 210 shown in FIGS. 7A and 7B is disposed on one long side edge of the lower substrate 110 , and the second shape changing means 220 is on the other long side edge of the lower substrate 110 . It is substantially the same as described in conjunction with FIGS. 4A and 4B except for the arrangement. On the other hand, the flexible film 150 and the circuit board 170 may be fixed by being folded from one long side edge to the opposite surface of one surface of the lower substrate 110 .

8A and 8B are perspective views illustrating still another example of a lower substrate and first and second shape changing means. In FIGS. 8A and 8B , only the lower substrate 110 and the first and second shape changing means 210 and 220 are illustrated for convenience of description.

The first and second shape changing means 210 and 220 shown in FIGS. 8A and 8B are the same as those described in connection with FIGS. 4A and 4B except that they are disposed on one long side edge of the lower substrate 110 . Practically the same. On the other hand, the flexible film 150 and the circuit board 170 may be fixed by being folded from one long side edge or the other long side edge to the opposite surface of one surface of the lower substrate 110 .

9A and 9B are perspective views illustrating a flexible display device according to a second exemplary embodiment of the present invention. 10 is an exploded perspective view of the flexible display device of FIG. 9A . 9A, 9B, and 10 , the flexible display device FDIS according to the second exemplary embodiment of the present invention includes a flexible display panel 100 , a transparent adhesive layer 300 , a touch panel 400 , and a polarizing plate. (500). The transparent adhesive layer 300, the touch panel 400, and the polarizing plate 500 of the second embodiment of the present invention shown in FIGS. Since the transparent adhesive layer 300, the touch panel 400, and the polarizing plate 500 of the first embodiment of the present invention are substantially the same, detailed descriptions thereof will be omitted.

The flexible display panel 100 includes a lower substrate 110 , a plastic film 120 , an upper substrate 130 , a driving IC 150 , a flexible film 150 , a circuit board 160 , a timing control circuit 170 , It includes first and second shape changing means 210 and 220 , and a shape changing means driving unit 230 . 9A and 9B, and the lower substrate 110, the plastic film 120, the upper substrate 130, the driving IC 150, the flexible film 150, and the circuit of the second embodiment of the present invention shown in Figs. The board 160 and the timing control circuit 170 are the lower substrate 110, the plastic film 120, the upper substrate 130, and the drive of the first embodiment of the present invention shown in FIGS. 1A, 1B, and 2 . Since the IC 150 , the flexible film 150 , the circuit board 160 , and the timing control circuit 170 are substantially the same, a detailed description thereof will be omitted.

In addition, the first and second shape changing means 210 and 220 of the second embodiment of the present invention shown in Figs. 9A and 9B, and Fig. 10, except for their arrangement positions, are The first and second shape changing means 210 and 220 of the first embodiment of the present invention shown in FIG. 2 are substantially the same.

The first shape changing means 210 is disposed on one surface of the lower substrate 110 on which the plastic film 120 is disposed, and the second shape changing means 220 is disposed on the opposite surface of the one surface of the lower substrate 110 . can For example, the first shape changing means 210 may be disposed at the edge of one surface of the lower substrate 110 not covered by the plastic film 120 .

Specifically, as shown in FIGS. 4A and 4B , the first shape changing means 210 is disposed on one short side edge of the lower substrate 110 , and the second shape changing means 220 is disposed on the other short side edge of the lower substrate 110 . can be Alternatively, as shown in FIGS. 6A and 6B , the first and second shape changing means 210 and 220 may be disposed on one short side edge of the lower substrate 110 . At this time, when the first shape changing means 210 is disposed on one short edge of the lower substrate 110 not covered by the plastic film 120 as shown in FIGS. 9A, 9B, and 10, the flexible film ( 150) and the circuit board 160 may be fixed by being folded to opposite surfaces at another short side edge of the lower substrate.

Alternatively, as shown in FIGS. 7A and 7B , the first shape changing means 210 is disposed on any one long side edge of the lower substrate 110 , and the second shape changing means 220 is disposed on the other long side edge of the lower substrate. can Alternatively, as shown in FIGS. 8A and 8B , the first and second shape changing means 210 and 220 may be disposed on one long side edge of the lower substrate 110 . At this time, when the first shape changing means 210 is disposed on any one of the long side edges of the lower substrate 110 not covered by the plastic film 120 , the flexible film 150 and the circuit board 160 are formed on the lower substrate. It can be fixed by folding it to the opposite side at another long edge of the

11A and 11B are perspective views illustrating a flexible display device according to a third exemplary embodiment of the present invention. 12 is an exploded perspective view of the flexible display device of FIG. 11A . 11A, 11B, and 12 , the flexible display device FDIS according to the third exemplary embodiment of the present invention includes a flexible display panel 100 , a transparent adhesive layer 300 , a touch panel 400 , and a polarizing plate. (500). 11A and 11B, and the transparent adhesive layer 300, the touch panel 400, and the polarizing plate 500 of the third embodiment of the present invention shown in FIGS. Since the transparent adhesive layer 300, the touch panel 400, and the polarizing plate 500 of the first embodiment of the present invention are substantially the same, detailed descriptions thereof will be omitted.

The flexible display panel 100 includes a lower substrate 110 , a plastic film 120 , an upper substrate 130 , a driving IC 150 , a flexible film 150 , a circuit board 160 , a timing control circuit 170 , It includes first and second shape changing means 240 , 250 , and a shape changing means driving unit 230 . 11A and 11B, and the lower substrate 110, the plastic film 120, the upper substrate 130, the driving IC 150, the flexible film 150, and the circuit of the third embodiment of the present invention shown in Figs. The board 160 and the timing control circuit 170 are the lower substrate 110, the plastic film 120, the upper substrate 130, and the drive of the first embodiment of the present invention shown in FIGS. 1A, 1B, and 2 . Since the IC 150 , the flexible film 150 , the circuit board 160 , and the timing control circuit 170 are substantially the same, a detailed description thereof will be omitted.

The first shape changing means 240 is disposed on one surface of the lower substrate 110 on which the plastic substrate 120 is disposed. The second shape changing means 250 is disposed on a surface opposite to one surface of the lower substrate 110 . The first and second shape changing means 240 and 250 are connected to the shape changing means driving unit 230 to receive voltage from the shape changing means driving unit 230 .

The first shape changing means 240 may transform the lower substrate 110 into a first stable state as shown in FIG. 11A by a piezoelectric effect when a voltage is applied from the shape changing means driving unit 230 . In addition, the second shape changing means 250 may transform the lower substrate 110 to a second stable state as shown in FIG. 11B by a piezoelectric effect when a voltage is applied from the shape changing means driving unit 230 . have. Since the flexible display panel 100 has flexibility to be bent or bent, as the lower substrate 110 is deformed by the first and second shape changing means 240 and 250 , the flexible display panel 100 is can be deformed.

The first and second shape changing means 240 and 250 may be piezo actuators capable of providing a piezoelectric effect. For example, the first and second shape changing means 240 and 250 may be macro fiber composite (MFC) capable of providing a piezoelectric effect. A piezo actuator is a device that generates kinetic energy using electrical energy, and in an embodiment of the present invention, the piezoelectric effect is a reverse piezoelectric effect ( converse piezoelectric effect).

In this case, since the shape of the first and second shape changing means 240 and 250 is not changed by Joule's heat like the shape memory alloy, the light emitting layer EL of the pixel array PA is deteriorated. Since there is a low possibility of the pixel array being formed, it is not necessary to be disposed so as not to overlap the pixel array PA as in FIGS. 11A and 11B . A detailed description of the first and second shape changing means 240 and 250 will be described later with reference to FIGS. 13A and 13B .

13A and 13B are perspective views illustrating the lower substrate of FIGS. 11A and 11B and first and second shape changing means; 13A and 13B show only the lower substrate 110 and the first and second shape changing means 240 and 250 for convenience of description.

13A and 13B , the first shape changing means 240 is disposed on one edge of the lower substrate 110 , and the second shape changing means 250 is disposed on the opposite side of the lower substrate 110 . . In FIGS. 13A and 13B , the second shape changing means 250 disposed on the opposite surface of the lower substrate 110 is not visible, so it is illustrated with a dotted line.

In the third embodiment of the present invention, since the shapes of the first and second shape changing means 240 and 250 are not changed by Joule's heat, the light emitting layer EL of the pixel array PA deteriorates. Since there is a low possibility of being formed, there is no need to be disposed so as not to overlap the pixel array PA. However, since the first shape changing means 240 is disposed on one surface of the lower substrate 110 on which the plastic film 120 is disposed, it is disposed on the edge of one surface of the lower substrate 110 not covered by the plastic film 120 . It is preferable to be When the first shape changing means 240 is disposed on one short edge of the lower substrate 110 that is not covered by the plastic film 120 , the flexible film 150 and the circuit board 160 are connected to the lower substrate. On the other short edge, it can be folded to the opposite side and secured.

11A, 11B and 13A and 13B illustrate that the first and second shape changing means 240 and 250 are macro fiber composite (MFC). In this case, each of the first and second shape changing means 240 and 250 includes the first and second electrodes e1 and e2 , and the second patterned on the first polyimide film pi1 as shown in FIG. 14 . The third and fourth electrodes e3 and e4 patterned on the polyimide film pi2 are disposed between the first polyimide film pi1 and the second polyimide film pi2, and a piezoelectric fiber ) formed using a piezoelectric composite material (fiber), a first polyimide film (pi1) and a first epoxy (epoxy1) disposed between the piezoelectric composite material (fiber), and a second polyimide film (pi2) and a piezoelectric composite material (fiber) ) and a second epoxy (epoxy2) disposed between.

Each of the first and second electrodes e1 and e2 includes a plurality of slits s, and the slits s of the first electrode e1 and the slits s of the second electrode e2 are interdigitated. It may be formed alternately as interdigitated. That is, the slit of the second electrode e2 is disposed between the slits of the first electrode e1 , and the slit of the first electrode e1 is disposed between the slits of the second electrode e2 . (s) may be placed.

In addition, each of the third and fourth electrodes e3 and e4 includes a plurality of slits s, slits s of the third electrode e3 and slits s of the fourth electrode e4. The fields may be alternately interdigitated. That is, the slit of the fourth electrode e4 is disposed between the slits s of the third electrode e3 , and the slit of the third electrode e3 is disposed between the slits s of the fourth electrode e4 . (s) may be placed.

When appropriate voltages are applied to the first to fourth electrodes e1 to e4 , a piezoelectric effect is generated by the piezoelectric composite material (fiber) according to the degree of the formed electric field. For example, the piezoelectric composite material (fiber) may contract or extend according to a voltage applied to the first to fourth electrodes e1 to e4 or generate vibration. Appropriate voltages applied to the first to fourth electrodes e1 to e4 may be predetermined through a prior experiment. When no voltage is applied to the first to fourth electrodes e1 to e4 , the piezoelectric effect does not occur due to the piezoelectric composite material (fiber).

The first shape changing means 240 may transform the lower substrate 110 from the second stable state to the first stable state as shown in FIG. 13A by a piezoelectric effect when a voltage is applied thereto. The second shape changing means 250 may transform the lower substrate 110 from the first stable state to the second stable state as shown in FIG. 13B by a piezoelectric effect when a voltage is applied thereto.

As described above, in the third embodiment of the present invention, a piezoelectric effect is generated in the first shape changing means 240 to deform the lower substrate 110 from the second stable state to the first stable state, and this A voltage is applied to the first shape changing means 240 for this purpose. In addition, in the third embodiment of the present invention, a piezoelectric effect is generated in the second shape changing means 250 to deform the lower substrate 110 from the first stable state to the second stable state, and for this purpose, the second shape A voltage is applied to the change means 250 . As a result, in the third embodiment of the present invention, the lower substrate 110 may be deformed by the first and second shape changing means 240 and 250 even if the user does not directly apply force.

15A and 15B are perspective views illustrating a flexible display device according to a fourth exemplary embodiment of the present invention. 16 is an exploded perspective view of the flexible display device of FIG. 15A . 15A, 15B, and 16 , the flexible display device FDIS according to the fourth embodiment of the present invention includes a flexible display panel 100 , a transparent adhesive layer 300 , a touch panel 400 , and a polarizing plate. (500). 15A and 15B, and the transparent adhesive layer 300, the touch panel 400, and the polarizing plate 500 of the fourth embodiment of the present invention shown in FIGS. Since the transparent adhesive layer 300, the touch panel 400, and the polarizing plate 500 of the first embodiment of the present invention are substantially the same, detailed descriptions thereof will be omitted.

The flexible display panel 100 includes a lower substrate 110 , a plastic film 120 , an upper substrate 130 , a driving IC 150 , a flexible film 150 , a circuit board 160 , a timing control circuit 170 , It includes first and second shape changing means 240 , 250 , and a shape changing means driving unit 230 . 15A and 15B, and the lower substrate 110, the plastic film 120, the upper substrate 130, the driving IC 150, the flexible film 150, and the circuit of the fourth embodiment of the present invention shown in Figs. The board 160 and the timing control circuit 170 are the lower substrate 110, the plastic film 120, the upper substrate 130, and the drive of the first embodiment of the present invention shown in FIGS. 1A, 1B, and 2 . Since the IC 150 , the flexible film 150 , the circuit board 160 , and the timing control circuit 170 are substantially the same, a detailed description thereof will be omitted.

In addition, the first and second shape changing means 240 and 250 of the fourth embodiment of the present invention shown in Figs. 15A and 15B, and Fig. 16, except for their arrangement positions, are shown in Figs. 1A, 1B, and The first and second shape changing means 240 and 250 of the third embodiment of the present invention shown in FIG. 2 are substantially the same.

The first shape changing means 240 is disposed on one surface of the lower substrate 110 on which the plastic film 120 is disposed, and the second shape changing means 250 is disposed on the opposite surface of the one surface of the lower substrate 110 . can Since the first shape changing means 240 is disposed on one surface of the lower substrate 110 on which the plastic film 120 is disposed, it is preferable to be disposed on the edge of one surface of the lower substrate 110 not covered by the plastic film 120 . desirable. When the first shape changing means 240 is disposed on one short edge of the lower substrate 110 that is not covered by the plastic film 120 , the flexible film 150 and the circuit board 160 are connected to the lower substrate. On the other short edge, it can be folded to the opposite side and secured.

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made within the scope without departing from the technical spirit of the present invention. . Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The protection scope of the present invention should be construed by the claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

FDIS: flexible display device 100: flexible display panel
110: lower substrate 120: plastic substrate
130: upper substrate 140: driving IC
150: flexible film 160: circuit board
170: timing control circuit 210, 240: first shape change means
220, 250: second shape changing means 230: shape changing means driving unit
300: transparent adhesive layer 400: touch panel
500: polarizer

Claims (12)

a lower substrate made of a bistable metal material stably maintaining at least two shapes;
a plastic film disposed on the lower substrate and having a pixel array formed thereon;
a first shape changing means disposed on one surface of the lower substrate facing the plastic film to transform the lower substrate into a first stable state; and
and a second shape changing means disposed on a surface opposite to the one surface of the lower substrate to deform the lower substrate to a second stable state. The method of claim 1,
The lower substrate is larger than the plastic film,
The first shape changing means is disposed on one surface of the lower substrate that is not covered by the plastic film. The method of claim 1,
The first and second shape changing means do not overlap the pixel array. 4. The method of claim 3,
The first shape changing means is disposed on an edge of one surface of the lower substrate, and the second shape changing means is disposed on an edge of an opposite surface of the one surface of the lower substrate. 5. The method of claim 4,
The first and second shape changing means are disposed at one short side edge of the lower substrate or at any one long side edge of the lower substrate. 5. The method of claim 4,
The first shape changing means is disposed on any one short side edge of the lower substrate and the second shape changing means is disposed on the other short side edge of the lower substrate,
The first shape changing means is disposed on one long side edge of the lower substrate, and the second shape changing means is disposed on the other long side edge of the lower substrate. The method of claim 1,
Each of the first and second shape changing means is a twisted shape memory alloy. 7. The method of claim 6,
When a voltage is applied to the first shape changing means, the lower substrate is deformed from the second stable state to the first stable state by contraction of the first shape changing means, and the voltage is applied to the second shape changing means When applied, the lower substrate is deformed from the first stable state to the second stable state by contraction of the second shape changing means. The method of claim 1,
Each of the first and second shape change means,
first and second electrodes formed on the first plastic film and each having a plurality of slits;
third and fourth electrodes formed on the second plastic film and each having a plurality of slits; and
It is disposed between the first and second plastic films and includes a piezoelectric composite formed using a piezoelectric fiber,
The slits of the first electrode and the slits of the second electrode are alternately arranged,
The slits of the third electrode and the slits of the fourth electrode are alternately arranged. 10. The method of claim 9,
When a voltage is applied to the first to fourth electrodes of the first shape changing means, the lower substrate is deformed from the second stable state to the first stable state by the piezoelectric effect of the first shape changing means, , a flexible display device that is deformed from the first stable state to the second stable state by the piezoelectric effect of the second shape changing means when a voltage is applied to the first to fourth electrodes of the second shape changing means . The method of claim 1,
The bistable material is a beryllium copper alloy. The method of claim 1,
a driving IC for driving the pixels of the pixel array;
a flexible film on which the driving IC is mounted and attached to the plastic film;
a circuit board attached to the flexible film; and
and a shape changing means driver mounted on the circuit board and configured to supply a voltage to the first and second shape changing means.

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