JP2020024420A - Display device - Google Patents

Abstract

To provide a new display device that is foldable and excels in portability.SOLUTION: Provided is a display device comprising a first housing 502, a second housing 504, a display panel 501, and a cover film 503, the first housing accommodating the display panel, the second housing accommodating the cover film, the display panel having flexibility, the cover film having flexibility and visible light permeability. When the display device is unfolded, the cover film is positioned on the display surface of the display panel, and when folding, the first housing can be folded before the second housing and then the second housing can be folded so as to cover the first housing. When folded, the radius of curvature is larger for the cover film than for the display panel.SELECTED DRAWING: Figure 3

Description

One embodiment of the present invention relates to an object, a method, or a manufacturing method. Alternatively, one embodiment of the present invention relates to a process, a machine, a manufacture, or a composition (composition of matter). In particular, one embodiment of the present invention relates to, for example, a semiconductor device, a display device, a light-emitting device, a power storage device, a driving method thereof, or a manufacturing method thereof. In particular, one embodiment of the present invention relates to a display device.

The social infrastructure related to information transmission means has been enhanced. As a result, various and abundant information can be obtained or transmitted not only at work or at home but also on the go.

A display device provided with a large screen capable of listing and displaying a large amount of information is suitable for an information terminal device.

In addition, portable information terminal devices capable of acquiring information even when they are away from home are being actively developed. It is important to be portable for use on the go. It is very convenient to be able to change the size of the information terminal device and the size of the display area accordingly.

A portable information terminal device is often used outdoors, and unexpected force may be applied to the portable information terminal device due to dropping or the like.

As an example of a display device that withstands a force applied from the outside and is not easily broken, a configuration in which the adhesion between a structure for separating a light-emitting layer and a second electrode layer is known (Patent Document 1). .

JP 2012-190794 A

One embodiment of the present invention has been made under such a technical background. Therefore, it is an object to provide a novel display device which is excellent in portability and can be folded. Another object is to provide a novel display device capable of displaying on a seamless large screen. Another object is to provide a novel display device which is highly resistant to external physical forces when folded or opened to use a large screen.

Note that the description of these objects does not disturb the existence of other objects. Note that one embodiment of the present invention does not need to solve all of these problems. It should be noted that issues other than these are naturally evident from the description of the specification, drawings, claims, etc., and that other issues can be extracted from the description of the specifications, drawings, claims, etc. It is.

One embodiment of the present invention is a display device including a first housing, a display panel, and a first layer. The first housing houses the display panel, and the display panel has flexibility. The first layer has flexibility and transparency to visible light, and at least a part of the first layer is in both the expanded state and the folded state of the display device. Positioned on the display surface of the display panel, the display surface of the display device in a folded state has a display region and a region that transmits visible light,
A display device.

Another embodiment of the present invention is a display device including a first housing, a display panel, and a first layer, wherein the first housing houses the display panel, and the display panel has flexibility. And the first layer has flexibility and transparency to visible light, and the first layer is positioned on the display surface of the display panel when the display device is unfolded. Further, the display device is capable of independently folding the first housing and the first layer. In particular, it is preferable that the first housing can be folded before the first layer when folded, and then the first layer can be folded so as to cover the first housing.

It is preferable that the display device having any of the above structures be capable of folding a part of the display surface of the display panel so that the display surface can be viewed from the outside.

It is preferable that the display device having any of the above structures include a second housing, and the second housing house the first layer.

It is preferable that the radius of curvature when the display device having each of the above structures is folded is larger in the first layer than in the display panel.

The display device having each of the above structures has the first layer and further has the second housing, so that the display panel is not directly subjected to external physical force even when the display device is expanded or folded. .

It is preferable that the display device having any of the above structures include a touch sensor in the first layer.

It is preferable that the display device having each of the above structures has an antireflection layer on at least one of the surfaces of the first layer and the display panel facing each other.

By providing the antireflection function, interference unevenness does not occur even if there is a distribution in the distance between the first layer and the display panel.

In the display device having each of the above structures, the first casing and the first layer are preferably removable from each other. Alternatively, the first housing and the second layer may be removable from each other. Thus, if either of them is broken, only the broken one can be replaced, and the cost of repair and the like can be reduced.

There is a high possibility that the first layer or the second housing which receives physical force from the outside becomes unusable, but since the first layer or the second housing can be made cheaper than the display panel, By having a replacement function, it is possible to repair cheaply.

It is preferable that the first layer have a thickness larger than that of the display panel. The thicker the first layer, the more
The resistance of the display device to physical force can be increased. According to one embodiment of the present invention, the radius of curvature of the first layer can be set to be larger than that of the display panel; therefore, there is an advantage that the thickness of the first layer is not limited as much as the display panel.

In this specification, a display device refers to an image display device. A module in which a connector, for example, an FPC (Flexible printed circuit) or a TCP (Tape Carrier Package) is attached to the display device;
The display device also includes a module in which a printed wiring board is provided before the TCP, or a module in which an IC (integrated circuit) is directly mounted on a substrate on which a light-emitting element is formed by a COG (Chip On Glass) method.

According to one embodiment of the present invention, a novel display device which can be folded and has excellent portability can be provided. Alternatively, it is possible to provide a novel display device capable of displaying on a seamless large screen. Further, it is possible to provide a novel display device which is highly resistant to external physical forces when folded or opened to use a large screen.

FIG. 4 illustrates a state where a display device according to an embodiment is expanded. 5A and 5B illustrate a state where only a display panel of a display device according to an embodiment is folded. 4A and 4B illustrate a state where a display device according to an embodiment is folded. 4A and 4B illustrate a structure of a display panel of a display device according to an embodiment.

<Example of problem that one embodiment of the present invention can solve>
2. Description of the Related Art A flexible display panel in which a display element and the like are provided on a flexible substrate is known.

In order to make a flexible display panel bendable with a small radius of curvature, the thickness and hardness of the display panel are limited, and the physical strength of the display panel may be reduced.

When a physical force is directly applied to a highly flexible display panel, there is a problem that a functional film or a functional element of the display panel cannot be protected. On the other hand, when a functional film having high hardness is provided on the display panel, there is a problem that the bendable radius of curvature increases.

<One embodiment of the present invention>
In the embodiment described below, even when the display panel is expanded and displayed on a large screen, even when the display panel is folded, the housing having the cover film suppresses the display panel from directly receiving a physical force from the outside. One aspect of the present invention created by paying attention to the above configuration is included.

The display device of one embodiment of the present invention includes a first housing, a second housing, a display panel, and a cover film. The first housing houses the display panel. The second housing houses the cover film. The display panel has flexibility. The cover film has flexibility and transparency to visible light.

In one embodiment of the present invention, in both the unfolded state and the folded state of the display device, at least a portion of the cover film is located on the display surface of the display panel, and the display surface of the display device in the folded state is It is preferable to have a display region and a region that transmits visible light.

Alternatively, in one embodiment of the present invention, in a state where the display device is expanded, the cover film is located on the display surface of the display panel, and folds the first housing before the second housing when folded. Preferably, the second housing can then be folded to cover the first housing.

It is preferable that the display device having any of the above structures be capable of folding a part of the display surface of the display panel so that the display surface can be viewed from the outside.

It is preferable that the display device having any of the above structures include a second housing, and the second housing house the first layer.

It is preferable that the radius of curvature when the display device having each of the above structures is folded is larger in the first layer than in the display panel. Further, it is preferable that the thickness of the first layer be larger than that of the display panel.

In the above configuration, by including the cover film and the second housing, the display panel is not directly subjected to a physical force from the outside when the display device is expanded or folded.

As a result, a novel display device which can be folded and has excellent portability can be provided. Alternatively, a novel display device capable of displaying information or the like on a seamless large screen can be provided. In addition, it is possible to provide a novel display device which is highly resistant to external physical force when folded or opened to use a large screen.

Embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that the form and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention is not construed as being limited to the description of the embodiments below. Note that in the structures of the invention described below, the same portions or portions having similar functions are denoted by the same reference numerals in different drawings,
The description of the repetition is omitted.

(Embodiment 1)
In this embodiment, a structure of a display device of one embodiment of the present invention will be described with reference to FIGS.

FIGS. 1A to 3A are top views of display devices according to one embodiment of the present invention, and FIGS. 1B to 3B illustrate corresponding display devices in FIGS. It is a side view of A).

1A and 1B illustrate a state where a display device of one embodiment of the present invention is developed. The display device of one embodiment of the present invention can be displayed on a large seamless screen by being developed.

As shown in an enlarged view of a portion surrounded by a dashed line in FIG.
The cover film 503 is preferably thick. In the present embodiment, the first housing 5
Although an example in which the thickness of the second housing 504 is equal to that of the second housing 504 is described, one embodiment of the present invention is not limited thereto.

FIGS. 2A and 2B illustrate a display device of one embodiment of the present invention in which only a display panel is folded.

FIGS. 3A and 3B illustrate a state where the display device of one embodiment of the present invention is folded. The display device of one embodiment of the present invention can be improved in portability by being folded.

The display device 500 described in this embodiment includes a folding mechanism 550 and a display panel 501.
, A first housing 502, a cover film 503, and a second housing 504. The first housing 502 houses the display panel 501. Note that the display panel 501 includes a display area 505 on which information and the like can be displayed. The second housing 504 includes a cover film 503.
To store. When the display panel 501 is folded, the display device 500 may be provided with a region 506 including only the cover film 503 and transmitting visible light.

When the display device is deployed, the display panel 501 has a structure in which a cover film 503 is provided on the display surface side, and the display panel 501 can reduce damage due to external physical force ( (See FIG. 1).

Each of the first housing 502 and the second housing 504 has a folding mechanism 550, and it is possible to fold only the first housing 502. At that time, the display panel 501
Is folded inside the first housing 502, and a part of the display surface is inside. The location on the inside makes it possible to reduce external physical damage (see FIG. 2).

By folding the second housing 504 so as to cover the first housing 502 after the first housing 502 is folded, the display panel 501 is physically separated from the outside by the first housing 502 or the cover film 503. It is possible to reduce the target damage (see FIG. 3). Note that the second housing 504 does not need to cover all of the first housing 502.

As a result, a novel display device 500 which can be folded and has excellent portability can be provided. Alternatively, a novel display device 500 that can display an image on a large screen without a seam can be provided. Further, it is possible to provide a novel display device which is highly resistant to external physical forces when folded or opened to use a large screen.

When the display device is folded, the first housing and the second housing are separately folded. At this time, the second housing folds with a larger radius of curvature than the first housing. Therefore, the cover film installed in the second housing does not need to have as much bending resistance as the display panel installed in the first housing.

In the present embodiment, the case where the display panel is folded in three is shown in the drawings as an example, but the present invention is not limited to this. As long as the display area can be viewed from the outside when folded, any manner of folding is an embodiment of the present invention.

Hereinafter, individual components included in the display device of one embodiment of the present invention will be described.

《Cover film》
The cover film 503 needs to reduce external damage to the display panel 501. Therefore, it is necessary that the hardness is high enough to prevent distortion or the like when an external force is applied. When the hardness is high, it is possible to suppress the occurrence of scratches or the like that degrade display quality. Further, since it is necessary to emit light from the display panel to the outside, it is necessary to have transparency to visible light.

When the hardness is increased, the bending characteristics are lowered. However, as shown in FIG. 3, the cover film 503 folds with a larger radius of curvature than the display panel 501, so that in one embodiment of the present invention, sufficient hardness and bending characteristics are obtained. Obtainable.

Note that the cover film 503 may be provided with a touch sensor function. Cover film 503
Since the display panel 501 and the display panel 501 have different housings, a sufficient distance can be obtained and the display panel 501 is not affected by the parasitic capacitance of the display panel. Therefore, the sensitivity can be increased even in a capacitive touch sensor.

Since the first housing 502 and the second housing 504 can be separately folded, the distance between the cover film 503 and the display panel 501 can be easily distributed in a plane. If interference fringes due to distribution occur, the display quality deteriorates. Therefore, it is preferable to perform an anti-reflection process on the display panel side of the cover film 503. As the non-reflection treatment, a moth-eye structure having low wavelength dependence is preferable.

The non-reflection processing may be performed on the display surface side of the display panel 501. Also, a cover film 503,
The operation may be performed on both of the display panels 501. By performing the non-reflection processing, it is possible to suppress interference fringes and increase the light extraction efficiency.

As a material of the cover film 503, various plastics having transparency to visible light can be used. For example, polyimide (PI), aramid, polyethylene terephthalate (PET), polyether sulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC), nylon, polyether ether ketone (P
EEK), polysulfone (PSF), polyetherimide (PEI), polyarylate (
PAR), plastics such as polybutylene terephthalate (PBT) and silicone resin can be used. In particular, it is preferable to use inexpensive PET or PEN. Since high bending characteristics are not required, the thickness can be made sufficiently thicker than the display panel 501. Generally, the thickness of a flexible display panel is 100 μm or less,
3 may have a thickness of 100 μm or more and less than 1000 μm, preferably 200 μm or more and 400 μm or less.

In order to increase the surface hardness, an inorganic film may be formed on a plastic film. As the inorganic film, a film having a high light-transmitting property with respect to visible light can be used. For example, a silicon oxide film,
A silicon nitride film, a silicon oxynitride film, a silicon nitride oxide film, an aluminum oxide film, or the like can be used. As the inorganic film, either a single layer or a stacked layer can be used.

Although the cover film 503 is required to reduce physical damage and the like of the display panel 501, it does not contribute to suppressing moisture penetration into the display panel. No problem. By using this microcrack, a cover film 503 having high surface hardness and high bendability can be manufactured.

The surface of the cover film 503 may be treated to have water repellency and oil repellency.

<< First housing, second housing >>
For the first housing and the second housing, a material which can maintain mechanical strength to some extent can be used. Specifically, plastic, metal, wood, or the like can be used.

The second housing 504 is provided with a window in order to emit light from the display panel to the outside. A cover film is provided on the window.

The first housing 502 and the second housing 504 can be individually removed. If either one breaks, it can be used by replacing it with a new one.

The cover film 503 and the second housing 504, which receive physical force from the outside, are more likely to be damaged and become unusable before the display panel 501 and the first housing 502. In addition, since the first housing 502 and the second housing 504 can be detached, only a part to be replaced can be replaced, and repair can be performed at low cost. Also, since the cover film 503 can be made cheaper than the display panel 501, it can be repaired cheaply by having a replacement function.

《Folding mechanism》
The folding mechanism 550 can be bent at a folded portion of the first housing 502 and the second housing 504. For example, a hinge, a flexible member, or the like can be applied to the folding mechanism 550.

Note that a ratchet mechanism or a non-slip may be provided in the folding mechanism 550 so that the angle of the bending can be adjusted as appropriate.

《Display panel》
The display panel 501 has flexibility.

The structure of the display panel 501 which can be applied to the display device 500 includes a display element which can display information included in a supplied signal. The display element includes, for example, a light-emitting element, electronic ink, a liquid crystal element, and the like. Note that a structure in which a light-emitting element is used as a display element is described in Embodiment 2 as an example of the display panel 501 in detail.

Note that this embodiment can be combined with any of the other embodiments in this specification as appropriate.

(Embodiment 2)
In this embodiment, a structure of a display panel that can be applied to the display device of one embodiment of the present invention is described.
This will be described with reference to FIG.

FIG. 4A is a top view illustrating a structure of a display panel that can be used for the display device of one embodiment of the present invention.

FIG. 4B is a cross-sectional view taken along a cutting line AB and a cutting line CD in FIG.

FIG. 4C is a cross-sectional view taken along section line EF in FIG. 4A.

<Explanation of top view>
The display panel 200 illustrated in this embodiment has one end 200L and the other end 200R (see FIG. 4A). Note that in one embodiment of the present invention, the display panel 200 may not have one or both of the one end 200L and the other end 200R.

Further, the display panel 200 exemplified in this embodiment has a display area 201.

A plurality of pixels 202 are provided in the display area 201, and a plurality of sub-pixels (for example, the sub-pixel 202R) are provided in the pixel 202. The sub-pixel is provided with a light-emitting element and a pixel circuit which can supply power for driving the light-emitting element.

The pixel circuit is electrically connected to a wiring which can supply a selection signal and a wiring which can supply a data signal.

The display panel 200 includes a scan line driver circuit 203g that can supply a selection signal,
The data line driver circuit 203s that can supply a data signal is provided.

<Explanation of cross section>
The display panel 200 includes a substrate 210 and a counter substrate 270 facing the substrate 210 (see FIG. 4B).

The substrate 210 includes a flexible substrate 210b and a barrier film 210a for preventing diffusion into a light emitting element.
And a laminate of an adhesive layer 210c for bonding the substrate 210b and the barrier film 210a.

The opposing substrate 270 includes a flexible substrate 270b and a barrier film 27 for preventing diffusion to a light emitting element.
0a and a laminate of an adhesive layer 270c for bonding the substrate 270b and the barrier film 270a.

Further, the sealing material 260 bonds the counter substrate 270 and the substrate 210 together. Further, the pixel circuit and the light-emitting element (for example, the first light-emitting element 250R) are provided between the substrate 210 and the counter substrate 270.

<< Pixel configuration >>
The pixel 202 includes a sub-pixel 202R, a sub-pixel 202G, and a sub-pixel 202B (see FIG.
)reference). The sub-pixel 202R includes a light-emitting module 280R, the sub-pixel 202G includes a light-emitting module 280G, and the sub-pixel 202B includes a light-emitting module 280B.

For example, the sub-pixel 202R includes a first light-emitting element 250R and a pixel circuit including a transistor 202t that can supply power to the first light-emitting element 250R (see FIG. 4B).
. The sub-pixel 202R includes a light-emitting module 280R, and the light-emitting module 280R includes a first light-emitting element 250R and an optical element (for example, a first coloring layer 267R).

The first light-emitting element 250R includes a first lower electrode 251R, an upper electrode 252, and a layer 253 containing a light-emitting organic compound between the first lower electrode 251R and the upper electrode 252.

The layer 253 containing a light-emitting organic compound includes a light-emitting unit 253a, a light-emitting unit 253b, and an intermediate layer 254 between the light-emitting units 253a and 253b.

The light-emitting module 280R includes the first coloring layer 267R on the counter substrate 270. The coloring layer only needs to transmit light having a specific wavelength, and for example, a layer that selectively transmits light exhibiting red, green, blue, or the like can be used. Note that a region that transmits light emitted from the light-emitting element as it is may be provided.

For example, the light-emitting module 280R includes the sealing material 260 in contact with the first light-emitting element 250R and the first coloring layer 267R.

The first coloring layer 267R is located at a position overlapping with the first light-emitting element 250R. Thereby, the first
A part of the light emitted from the light emitting element 250R passes through the sealing material 260 and the first coloring layer 267R and is emitted to the outside of the light emitting module 280R as indicated by an arrow in the drawing.

《Configuration of display panel》
The display panel 200 includes the light-blocking layer 267BM on the counter substrate 270. The light-blocking layer 267BM is provided so as to surround the coloring layer (for example, the first coloring layer 267R).

The display panel 200 includes the antireflection layer 267p at a position overlapping the display region 201.

The display panel 200 includes an insulating film 221. The insulating film 221 covers the transistor 202t. Note that the insulating film 221 can be used as a layer for planarizing unevenness due to a pixel circuit. Further, an insulating film in which a layer which can suppress diffusion of impurities into the transistor 202t and the like can be used as the insulating film 221.

The display panel 200 includes a light-emitting element (eg, a first light-emitting element 250R) over the insulating film 221.

The display panel 200 has a structure in which the partition wall 22 overlapping the end of the first lower electrode
8 (see FIG. 4C). Further, a spacer 229 for controlling the distance between the substrate 210 and the counter substrate 270 is provided on the partition wall 228.

<< Configuration of data line drive circuit >>
The data line driving circuit 203s includes a transistor 203t and a capacitor 203c. Note that the driver circuit can be formed over the same substrate as the pixel circuit in the same step as the pixel circuit.

《Other configuration》
The display panel 200 includes a wiring 211 that can supply a signal, and a terminal 219 is provided for the wiring 211. Note that an FPC (flexible print circuit) 209 which can supply a signal such as a data signal and a synchronization signal is electrically connected to the terminal 219.

Note that a printed wiring board (PWB) may be attached to the FPC. The display panel in this specification includes not only the display panel main body but also a state in which an FPC or a PWB is attached thereto.

Note that this embodiment can be combined with any of the other embodiments in this specification as appropriate.

200 display panel 200L end 200R end 201 display area 202 pixel 202B sub-pixel 202G sub-pixel 202R sub-pixel 202t transistor 203c capacitance 203g scanning line driving circuit 203s data line driving circuit 203t transistor 210 substrate 210a barrier film 210b substrate 210c adhesive layer 211 wiring 219 Terminal 221 Insulating film 228 Partition 229 Spacer 250R Light emitting element 251R Lower electrode 252 Upper electrode 253 Layer 253a Light emitting unit 253b Light emitting unit 254 Intermediate layer 260 Sealing material 267BM Light shielding layer 267p Antireflection layer 267R Colored layer 270 Counter substrate 270a Barrier film 270b Substrate 270c Adhesive layer 280B Light emitting module 280G Light emitting module 280R Light emitting module 500 Display device 501 Display panel 502 First Casing 503 Cover film 504 Second casing 505 Display area 506 Visible light transmitting area 550 Folding mechanism

Claims (5)

A display device having a display panel and a first layer,
The display panel has flexibility,
The first layer has flexibility, and has transparency to visible light,
The display panel and the first layer can be independently folded,
The display panel has a plurality of folded portions,
In a state where the display device is expanded, the first layer is located on a display surface of the display panel,
In a state where the display device is folded, the display panel can be folded so that a part of a display surface of the display panel is outside,
The display device, wherein the first layer can be folded so as to cover a part of a display surface of the display panel in a state where the display device is folded. A display device including a first housing having a display panel and a second housing having a first layer,
The display panel has flexibility,
The first layer has flexibility, and has transparency to visible light,
The first housing and the second housing can be independently folded,
The first housing has a plurality of folded portions,
In a state where the display device is expanded, the first layer is located on a display surface of the display panel,
In a state where the display device is folded, the display panel can be folded so that a part of a display surface of the display panel is outside,
The display device, wherein the first layer can be folded so as to cover a part of a display surface of the display panel in a state where the display device is folded. In claim 1 or claim 2,
When the display device is folded, the display panel can be folded before the first layer, and then the first layer can be folded so as to cover the display panel. Display device. In any one of claims 1 to 3,
The display device, wherein the display device can be folded so that a part of a display surface of the display panel can be viewed from outside. In any one of claims 1 to 4,
The display device, wherein the first layer is thicker than the display panel.

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