WO2022016399A1

WO2022016399A1 - Stretchable display and method of manufacturing display device using the same

Info

Publication number: WO2022016399A1
Application number: PCT/CN2020/103382
Authority: WO
Inventors: Kinoshita TOMOATSU
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2020-07-22
Filing date: 2020-07-22
Publication date: 2022-01-27
Also published as: CN116210039A

Abstract

A stretchable display (1) having an improved image quality. The stretchable display (1) comprises: a substrate (10); a plurality of pixel islands (20) arranged on the substrate (10); a first portion (100) in which the pixel islands (20) are arranged in a first direction with a first space (S1); and a second portion (200) in which the pixel islands (20) are arranged in a first direction with a second space (S2) which is different from the first space (S1). In addition, a method of manufacturing a display device attaching the stretchable display according to the present disclosure is provided. The method comprises: aligning the first portion (100) with a first position of the object; and aligning the second portion (200) with a second position of the object.

Description

STRETCHABLE DISPLAY AND METHOD OF MANUFACTURING DISPLAY DEVICE USING THE SAME

TECHNICAL FIELD

The present disclosure relates to a structure of a display panel, and particularly relates to a new design of a stretchable display.

BACKGROUND TECHNOLOGY

In recent years, a stretchable display that can be stretched and attached to an object, and can be formed by using stretchable materials, has been developed. Because the stretchable display can stretch partially or wholly in one direction or multiple directions, the stretchable display can be attached to various surfaces of an object.

PROBLEMS TO BE SOLVED BY THE INVENTION

FIG. 1 is a schematic top view of a stretchable display in the prior art. In FIG. 1, the stretchable display 1 comprises a substrate 10 and a plurality of pixel islands 20 arranged on the substrate 10.

Each pixel island 20 can emit light to form a part of image to be displayed by the stretchable display 1. In each pixel island 20, at least one pixel (not shown) and at least one thin film transistor (not shown) are incorporated. For example, a wiring layer pattern (not shown) is arranged on the substrate 10, and the pixel islands are electrically connected to each other through the wiring layer.

Referring again to FIG. 1, the pixel islands 20 of each row in the stretchable display are arranged at equal intervals with a space S in the row direction. An area where the pixel island 20 is located cannot stretch, but an area where the space S between the pixel islands 20 is located can stretch. This makes it possible for the stretchable display to be stretched in the row direction.

Also, the area where the space S is located does not emit light, in other words, the area where the space S is located is a non-light emitting area. Therefore, the presence of the space S which is required to realize the stretchable display reduces the pixel density of the stretchable display. That is, the pixel density of the stretchable display is low compared to a non-stretchable display wherein no or very small spaces between the pixel islands are provided.

When attaching the stretchable display to an object to be a display device, there may be an area where the stretchable display does not need to be stretched, such as a flat area. However, as described above, in a conventional stretchable display, all pixel islands are arranged at equal intervals with the space S between them. As a result, the image quality in the area where the stretchable display is not stretched (e.g. flat area) is reduced due to the structure of the stretchable display as described above.

Besides, there may be a case wherein the tensile force applied to the stretchable display changes depending on the position of the stretchable display due to the shape of an object to be a display device. In such a case, if all the pixel islands are arranged at equal intervals with the space S before stretching, the space after stretching between the pixel islands in the portion having a large stretching rate becomes relatively large, and the space after stretching between the pixel islands in the portion having a small stretching rate becomes relatively small. That is, because the pixel density after the stretchable display is attached becomes different between the portion having the large stretching rate and the portion having the small stretching rate, a homogeneous pixel density cannot be obtained, and thus unevenness in image quality will occur. As a result, the image quality will be reduced as the whole stretchable display.

In the invention disclosed in United States Patent Application, Publication No. 2018/0212188, which relates to a pixel encapsulation layer in a stretchable display, predetermined gaps as stretchable areas between pixel regions are provided. Because such gaps are uniformly provided over the whole stretchable display, the image quality in an area where the stretchable display is not stretched (for example, flat area) will be inferior to that of a non-stretchable display. In addition, in a case that the tensile force applied to the stretchable display changes depending on the position of the stretchable display due to the shape of an object to be a display device, because the spaces after stretching become different at different positions depending on the stretching rate, a homogeneous pixel density cannot be obtained, and thus unevenness in image quality will occur.

In the invention disclosed in United States Patent Application, Publication No. 2016/0240802, which discloses a stretchable display that is able to stretch in a predetermined direction, predetermined gaps before stretching as a stretchable area between light emitters are provided in a stretching direction. Because such gaps are uniformly provided over the whole stretchable display, the image quality in an area where the stretchable display is not stretched (for example, flat area) will be inferior to that of a non-stretchable display. In addition, in a case wherein the tensile force applied to the stretchable display changes depending on the position of the stretchable display due to the shape of an object to be a display device, because the spaces after stretching become different at different positions depending on the stretching rate, an homogeneous pixel density cannot be obtained, and thus unevenness in image quality will occur.

MEANS FOR SOLVING THE PROBLEMS

The present inventor found that the image quality of the stretchable display after it is attached to an object can be improved by making the spaces between the pixel islands before stretching be non-uniform.

A stretchable display according to one embodiment of the present invention comprises: a substrate; a plurality of pixel islands arranged on the substrate; a first portion in which the pixel islands are arranged in a first direction with a first space, and a second portion in which the pixel islands are arranged in the first direction with a second space which is different from the first space.

In the above configuration, the stretchable display may further comprise a third portion located between the first portion and the second portion, wherein the pixel islands in the third portion are arranged in the first direction with a third space which is intermediate between the first space and the second space.

In the above configuration, the second space may be larger than the first space, and the third space may gradually increase from the first portion toward the second portion.

In the above configuration, the first space may differ from the second space by at least 10%.

In the above configuration, at least one of the first space and the second space may be in the range from 10 μm to 200 μm.

In the above configuration, each of the plurality of pixel islands may comprise at least two pixels.

In the above configuration, the pixel may comprise an OLED.

In the above configuration, the substrate may be a stretchable substrate.

A method of manufacturing a display device according to another embodiment of the present invention is a method of manufacturing a display device attaching the stretchable display having the above configuration to an object, wherein the method comprises: aligning the first portion with a first position of the object; and aligning the second portion to a second position of the object.

In the above method, the stretching rate in the second portion may be larger than that of the first portion, and the second space may be larger than the first space.

In the above method, the pixel islands in the first portion may be arranged adjacent to each other.

In the above method, the stretching rate in the second portion may be larger than that of the first portion, and the second space may be smaller than the first space.

In the above method, the object may be in the shape of a cone or a truncated cone, and the stretchable display having the above configuration may be attached to the side surface of the cone or the truncated cone.

EFFECTS OF THE INVENTION

The stretchable display having the above configuration improves the image quality after it is attached to the object.

For example, in the stretchable display according to one embodiment of the present invention, the space between the pixel islands may be varied depending on the stretching rate at each portion. For example, the space between the pixel islands in an area where the stretchable display is not stretched (e.g. flat area) may be smaller. In this case, a portion to be stretched can be stretched at a desired stretching rate as usual, and at the same time, the image quality in the non-stretching area (e.g. the flat area) can be increased.

For example, in the stretchable display according to one embodiment of the present invention, the space before stretching between the pixel islands in a portion having a large stretching rate (that is, a portion that is relatively largely stretched) may be small, and the space before stretching between the pixel islands in a portion having a small stretching rate (that is, a portion that is relatively slightly stretched) may be large. In this case, it is possible to equalize the space after stretching between the pixel islands in the whole stretchable display, thereby eliminating unevenness in image quality and increasing the image quality of the whole stretchable display.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic top view for describing the basic structure of a conventional stretchable display.

FIG. 2 is a schematic top view for describing the basic structure of a stretchable display according to the present disclosure, and shows one aspect of the pixel island arrangement.

FIG. 3 is a cross-sectional view taken along the A-Aline in FIG. 2, and shows an exemplary structure of a pixel island in a stretchable display according to the present disclosure.

FIG. 4 shows another aspect of the pixel island arrangement of the stretchable display according to the present disclosure.

FIG. 5A is a graph showing pixel density versus stretching rate in a stretched portion of a stretchable display when a stretching rate E in a soft area is 5%.

FIG. 5B is a graph showing pixel density versus stretching rate in a stretched portion of the stretchable display when the stretching rate E in the soft area is 10%.

FIG. 5C is a graph showing pixel density versus stretching rate in a stretched portion of the stretchable display when the stretching rate E in the soft area is 20%.

FIG. 5D is a graph showing pixel density versus stretching rate in a stretched portion of the stretchable display when the stretching rate E in the soft area is 50%.

FIG. 6A is a cross-sectional view showing one step in an exemplary method of manufacturing a stretchable display according to the present disclosure.

FIG. 6B is a cross-sectional view showing another step in the exemplary method of manufacturing the stretchable display according to the present disclosure.

FIG. 6C is a cross-sectional view showing yet another step in the exemplary method of manufacturing the stretchable display according to the present disclosure.

FIG. 6D is a cross-sectional view showing yet another step of the exemplary method of manufacturing the stretchable display according to the present disclosure.

FIG. 7 shows (a) a schematic top view and (b) a schematic perspective view of a display device in which four apexes of an image displaying surface are not only rounded in plane but also rounded in a depth direction.

FIG. 8 shows one aspect of pixel island arrangement of the stretchable display according to the present disclosure, which is suitable for attaching to the display device of FIG. 7.

FIG. 9 shows another aspect of pixel island arrangement of the stretchable display according to the present disclosure, which is suitable for attaching to the display device of FIG. 7.

FIG. 10 shows yet another aspect of pixel island arrangement in the stretchable display according to the present disclosure.

FIG. 11 shows (a) an overall view and (b) a partially enlarged view which illustrate a state in which the stretchable display shown in FIG. 10 is attached to the side surface of a truncated cone-shaped object.

DESCRIPTION OF EMBODIMENTS

FIG. 2 shows a stretchable display 2 according to one embodiment of the present disclosure. The stretchable display 2 comprises: a substrate 10, a plurality of pixel islands 20 arranged on the substrate 10, a first portion 100 in which the pixel islands 20 are arranged with a first space S1 in a first direction which is a row direction, and a second portion 200 in which the pixel islands 20 are arranged with a second space S2 different from the first space S1 in the first direction. The first space S1 preferably differs from the second space S2 by at least 10%. When the first space S1 differs from the second space S2 by 10%or more, the improvement of the image quality of the stretchable display 2 after it is attached to an object becomes significant. For example, the first space S1 may differ from the second space S2 by 20%or more, 50%or more, or 80%or more.

The substrate 10 may be a stretchable substrate. The substrate 10 can stretch or contract within the elastic range of the substrate 10. The substrate 10 may be made of an elastic and/or stretchable material. The substrate 10 may be made of, for example, polydimethylsiloxane (PDMS) , epoxy, polystyrene, or polyurethane.

The pixel island 20 has a function of emitting light toward the top of the drawing, and each pixel island 20 emits light of various colors, such that the stretchable display can display an image.

The structure of the pixel island 20 will be described with reference to FIG. 3. FIG. 3 is a cross-sectional view taken along the A-A line in FIG. 2 and shows an exemplary structure of the pixel island 20 in the stretchable display according to the present disclosure. Referring to FIG. 3, the pixel island 20 comprises: for example, a pixel substrate 30; a thin film transistor (TFT) 40 on the pixel substrate 30; a planarization layer 50 on the TFT 40; a pixel 60 on the planarization layer 50; and a thin film encapsulation layer 70 on the pixel 60.

The pixel substrate 30 may include an organic material layer. The organic material layer may be made of, for example, polyether sulfone (PES) , polyacrylate, polyetherimide (PEI) , polyethylene naphthalate (PEN) , polyethylene terephthalate (PET) , polyphenylene sulfide (PPS) , polyarylate, polyimide, polycarbonate (PC) , triacetyl cellulose (TAC) , cellulose acetate propionate (CAP) , or a combination thereof.

The pixel substrate 30 may include an inorganic material layer. The inorganic material layer may be made of, for example, silicon oxide (SiO _x) or silicon nitride (SiN _x) .

The TFT 40 is provided to control the emission of light from the pixel 60, and may be formed using a well-known manner in the field of display technology.

The planarization layer 50 is provided to provide a flat surface on which the pixels 60 are arranged. The planarization layer 50 may be made of, for example, polyimide resin, acrylic resin, tetraethyl orthosilicate (TEOS) , silicon oxide, silicon nitride, or a combination thereof.

The pixel 60 may comprise an organic light emitting diode (OLED) . The OLED may comprise: an anode; a hole injection layer (HIL) ; a hole transport layer (HTL) ; a light emitting layer (EML) ; an electron transport layer (ETL) ; an electron injection layer (EIL) ; and a cathode. The OLED is preferably used in the stretchable display of the present disclosure because it has a wide viewing angle, good contrast, quick response, high brightness, excellent driving voltage characteristics, and color reproducibility. However, the pixel 60 in the present disclosure is not limited to the OLED, and any light emitting element having a function of emitting light to display an image is available.

The sub-pixel arrangement of the pixel 60 may adopt the RGB stripe manner in which three color sub-pixels of red, green and blue are arranged in the same size to form one pixel. Alternatively, the sub-pixel arrangement of the pixel 60 may adopt the RGB PenTile manner in which three color sub-pixels of red, green, and blue are arranged in different sizes to form one pixel. However, the arrangement manner of the sub-pixels in the present disclosure is not limited to the above-mentioned manners, and any arrangement manner is available as long as it can achieve a function of displaying an image.

In the pixel island 20 shown in FIG. 3, two pixels 60 are formed within one pixel island, but the number of the pixel 60 may be one, or be two or more. When the pixel island 20 includes at least two pixels, the image quality will be improved.

The thin film encapsulation layer 70 is provided to protect the pixel 60 and the pixel island 20. The thin film encapsulation layer 70 may include an organic encapsulation layer. The organic encapsulation layer may be made of, for example, polyethylene terephthalate, polyimide, polycarbonate, epoxy, polyethylene, polyacrylate, or a combination thereof.

The thin film encapsulating layer 70 may include an inorganic encapsulation layer. The inorganic encapsulation layer may be made of, for example, silicon nitride (SiN _x) , aluminum oxide (Al ₂O ₃) , silicon dioxide (SiO ₂) , titanium nitride (TiO ₂) , or a combination thereof.

The pixel islands 20 may be electrically connected to each other through a wiring layer 80. The wiring layer 80 may be made of a material capable of conducting current and capable of stretching in response to the stretching of the stretchable display 2. The wiring layer 80 may be made of, for example, a metal such as gold or silver, or a conductive paste in which conductive fillers are dispersed in an organic binder.

The stretchable display 2 may further comprise an overcoat layer 90 that covers the plurality of pixel islands 20. The overcoat layer 90 is provided to protect the plurality of pixel islands 20. The overcoat layer 90 may be made of an elastic and stretchable material. The overcoat layer 90 may be made of, for example, polydimethylsiloxane (PDMS) , epoxy, polystyrene, or polyurethane.

As can be seen from the above-mentioned structure of the pixel island 20, the pixel island 20 cannot stretch. Therefore, the stretchable display can stretch by stretching the substrate 10 and the overcoat layer 90 located in the gap between the pixel islands (that is, the space S1 and the space S2) . The stretchable area located in the gap between the pixel islands is referred to below as soft area.

Referring again to FIG. 2, the pixel islands 20 in the first portion 100 are arranged with a first space S1 in the first direction which is the row direction. Also, the pixel islands 20 in the second portion 200 are arranged in the first direction with a second space S2 different from the first space S1. At least one of the first space S1 and the second space S2 is preferably in the range of 10 μm to 200 μm. By setting the space in this range, a desired image quality can be obtained after the stretchable display is attached.

The second space S2 may be larger than the first space S1. For example, the second space S2 may be larger than the first space S1 by 10%or more, 50%or more, 100%or more, or 200%or more. Specifically, the size of the soft area in the second portion 200 may be larger than the size of the soft area in the first portion 100, such that the second portion 200 can largely stretch compared to the first portion 100. Accordingly, the second portion 200 may be applied to a portion where the stretchable display is relatively largely stretched, such that the second portion 200 can be stretched with a required range and attached to an object of a display device. On the other hand, the first portion 100 may be applied to a portion where the stretchable display is not stretched at all or slightly stretched. Because the pixel density in the first portion 100 is higher than the pixel density in the second portion 200, the image quality of the portion where the stretchable display is not stretched at all or is slightly stretched can be improved. Thus, it is possible to increase the image quality of the portion where the high image quality is required while increase the stretchability of the portion where the stretchability is required rather than the image quality. Note that the arrangement design of the pixel island 20 is not limited to the first direction as described above, and is applicable to a second direction intersecting the first direction.

FIG. 4 shows another aspect of arrangement of the pixel islands 20 in the stretchable display 2 according to the present disclosure. The arrangement of the pixel islands 20 shown in FIG. 4 is different from that of the pixel islands 20 shown in FIG. 2 in the point that a third portion 300 is provided between the first portion 100 and the second portion 200. The pixel islands 20 in the third portion 300 may be arranged in the first direction with a third space S3 that is intermediate between the first space S1 and the second space S2. Because the pixel density in the third portion 300 is between the pixel density of the first portion 100 and the pixel density of the second portion 200, the difference in image quality between the image displayed in the first portion 100 and the image displayed in the second portion 200, in other worlds the boundary of the image quality between the first portion 100 and the second portion 200 can be obscured.

Also, the second space S2 may be larger than the first space S1, and the third space S3 may vary so as to gradually increase from the first portion 100 toward the second portion 200. By gradually varying the third space S3, the difference in image quality between the image displayed in the first portion 100 and the image displayed in the second portion 200 can further effectively be obscured. In other words, the sharp boundary of the image quality between the first portion 100 and the second portion 200 can be eliminated.

Next, the relationship between the stretching rate and the pixel density in a stretched portion of the stretchable display will be described. Specifically, this relationship is related to the space S between the pixel islands and the stretching rate E of the soft area located in the space S. Here, the “stretched portion of the stretchable display” means a part or the whole of the stretchable display including the pixel islands and the soft areas. The “stretched portion of the stretchable display” may be a part or the whole of the stretchable display which is intended to be stretched.

FIG. 5A to FIG. 5D show graphs which each simulate the pixel density versus the stretching rate of the stretched portion of the stretchable display when the stretching rate E in the soft area is 5%, 10%, 20%and 50%, respectively.

Specifically, the stretching rate E in the soft area means the stretching amount with which the area located in the space S between the pixel islands 20 shown in FIG. 3 can be stretched.

W indicated in each graph of FIG. 5A to FIG. 5D is the width of the thin film encapsulation layer 70 which surrounds the side of the pixel island 20 shown in FIG. 3. Each of W10, W20, W30, W50, and W100 means that the width of the thin film encapsulation layer 70 is 10 μm, 20 μm, 30 μm, 50 μm, and 100 μm, respectively. In each graph of FIG. 5A to FIG. 5D, five straight lines are plotted based on the values of the width W of the thin film encapsulation layer 70. The thin film encapsulation layer 70 does not stretch. Because the width W of the thin film encapsulation layer 70 is the extra width of the unstretched portion included in each pixel island, it can be understood that the unstretched area increases as the value of W increases. Also, in FIG. 5A to FIG. 5D, the width of each pixel island 20 excluding the thin film encapsulation layer 70 is set to about 54 μm.

Furthermore, each straight line in each graph of FIG. 5A to FIG. 5D shows five points, and the value of the space S between the pixel islands 20 shown in FIG. 3 is different at each point. Specifically, the five points of each straight line have values of S different from each other, and have values of 13 μm, 27 μm, 54 μm, 108 μm, and 216 μm in order from the left. For example, referring to FIG. 5B, because the soft area can stretch by 10% (that is, E=10%) , in the case that the width W of the thin film encapsulation layer 70 is set to 50 μm, and the space S between the pixel islands 20 is set to 108 μm (that is, the fourth point from the left of the straight line of W50) , when the stretched portion of the stretchable display is stretched by 5% (that is, when the value of the x-axis is 5%) , it can be seen that the pixel density is approximately 120 (ppi) . If the portion to be stretched of the stretchable display can be stretched by 5%, it can be said that the stretchable display comprises a stretching function as a stretchable display.

As can be seen from the graph of FIG. 5A, it can be understood that in the case that the stretching rate E in the soft area is 5%, that is, the soft area can stretch by only 5%, it is difficult to stretch the portion to be stretched of the stretchable display by 5%, even if the space S between the pixel islands is set larger than 216 μm, . In addition, it can be seen that in order to stretch the portion to be stretched of the stretchable display by 5%, the space S between the pixel islands must be set larger than 216 μm, and as a result the pixel density must be significantly reduced.

As can be seen from the graph of FIG. 5B, it can be understood that in the case wherein the stretching rate E in the soft area is 10%, that is, the soft area can stretch by 10%, the portion to be stretched of the stretchable display can be stretched by 5%by setting the space S between the pixel islands from 54 μm to 216 μm. For example, when the width W is set to 10 μm and the space S is set to 54 μm, even if the portion to be stretched of the stretchable display is stretched by 5%, the pixel density thereof of about 200 (ppi) can be obtained.

As can be seen from the graph of FIG. 5C, it can be understood that in the case wherein the stretching rate E in the soft area is 20%, that is, the soft area can stretch by 20%, the portion to be stretched of the stretchable display can be stretched by 5%by setting the space S between the pixel islands from 27 μm to 54 μm. For example, when the width W is set to 30 μm and the space S is set to 27 μm, even if the portion to be stretched of the stretchable display is stretched by 5%, the pixel density thereof of about 240 (ppi) can be obtained.

Finally, as can be seen from the graph of FIG. 5D, it can be understood that in the case wherein the stretching rate E in the soft area is 50%, that is, the soft area can stretch by 50%, the portion to be stretched of the stretchable display can be stretched by 5%even by setting the space S between the pixel islands less than 13 μm. That is, if a material which has a large value of E is employed, the width W and the space S can be small, and thereby an image having high pixel density can be displayed.

FIG. 6A to FIG. 6D show an exemplary method of manufacturing a stretchable display of the present disclosure.

As shown in FIG. 6A, a pixel substrate layer 32 is formed on a first support substrate 800. The first support substrate 800 supports the pixel substrate layer 32 and may be made of, for example, glass, metal, or ceramic.

The pixel substrate layer 32 may be formed of, for example, an organic material layer having polyimide and/or an inorganic material layer having SiO _x, SiN _y, SiO _xN _y, or combination thereof.

The organic material layer may be formed by applying polyimide in a liquid state and then curing it, and as needed, may be formed as multilayer by repeatedly carrying out applying and curing polyimide. The organic material layer may be coated on the first support substrate 800 according to spin coating, slit coating, and/or ink-jet coating process. The inorganic material layer may be formed by chemical vapor deposition.

The organic material layer and the inorganic material layer may be formed as a single layer respectively, or at least one of the organic material layer and the inorganic material layer may be formed as multilayer, or furthermore the organic material layer and the inorganic material layer may be alternately and repeatedly stacked.

As shown in FIG. 6A, a thin film transistor 40, a planarization layer 50, and pixel 60 are formed on the pixel substrate layer 32.

As shown in FIG. 6B, the first support substrate 800 is removed from the pixel substrate layer 32 and the pixel substrate layer 32 is attached to a substrate 10.

The substrate 10 may be formed by coating and curing, for example, polydimethylsiloxane (PDMS) or polyurethane (PU) on a second support substrate 900. The substrate 10 may be attached to the pixel substrate layer 32, for example, by using an adhesive layer (not shown) .

As shown in FIG. 6C, the planarization layer 50 and the pixel substrate layer 32 are subject to etching by means of lithography, etc., and then a pattern of pixel islands 20 is formed.

As shown in FIG. 6D, the thin film encapsulation layer 70 and the overcoat layer 90 are formed to encapsulate the pixel islands 20. Finally, the substrate 10 is detached from the second support substrate 900 and then the stretchable display of the present disclosure is obtained.

The thin film encapsulation layer 70 may include an organic encapsulation layer. The organic encapsulation layer may be made of, for example, polyethylene terephthalate, polyimide, polycarbonate, epoxy, polyethylene, polyacrylate, or a combination thereof, and may be formed by, for example, ink-jet printing.

The thin film encapsulation layer 70 may include an inorganic encapsulation layer. The inorganic encapsulation layer may be made of, for example, silicon nitride (SiN _x) , aluminum oxide (Al ₂O ₃) , silicon dioxide (SiO ₂) , titanium nitride (TiO ₂) , or a combination thereof, and may be formed by, for example, chemical vapor deposition or physical vapor deposition.

The overcoat layer 90 may be formed by coating and curing, for example, polydimethylsiloxane (PDMS) or polyurethane (PU) .

The method of manufacturing a display device according to another embodiment of the present disclosure is a method attaching the stretchable display having the above-mentioned configuration to an object to produce a display device, wherein the method comprises: aligning the first portion to a first position of the object; and aligning the second portion to a second position of the object.

FIG. 7 shows an example of the display device in which the stretchable display 2 shown in FIG. 2 is attached to the object. FIG. 7 (a) is a schematic top view which shows an image displaying surface of the display device, and FIG. 7 (b) is a schematic perspective view of the display device. The display device of FIG. 7 has a rectangular parallelepiped shape, as can be seen from FIG. 7 (a) , each apex of the rectangular parallelepiped is rounded in plane. Furthermore, as can be seen from FIG. 7 (b) , each apex is also rounded in a depth direction. Accordingly, in the case that one surface of the rectangular parallelepiped is designed as a full screen display, that is, continuously displaying an image up to four apexes of the image displaying surface, four portions of the stretchable display corresponding said four apexes are needed to be largely stretched compared to the other portion in order to attach it to the object.

In the display device having the shape shown in FIG. 7, the positions of four apexes of the image displaying surface are designated as a second position 450 of the object and another position is designated as a first position 400 of the object. In this case, the method of manufacturing the display device attaching the stretchable display of the present disclosure to the object comprises: aligning the first portion 100 of the stretchable display with the first position 400 of the object; and aligning the second portion 200 of the stretchable display with the second position 450 of the object. The stretching rate in the second portion 200 of the stretchable display may be larger than that in the first portion 100 of the stretchable display, and the second space S2 may be larger than the first space S1.

FIG. 8 shows one aspect of the arrangement of the pixel islands 20 in the stretchable display 2 according to the present disclosure, which is suitable for attaching to the display device of FIG. 7. The pixel islands 20 in the second portion 200 corresponding to the second position 450 are arranged in the first direction with the second space S2. The space S2 may be larger than the space S1. Accordingly, the image quality of the stretchable display in the second position 450 will be reduced due to the reduction of the pixel density, however, the stretchable display can be smoothly attached to the object by stretching it as needed. On the other hand, the pixel islands 20 in the first portion 100 corresponding to the first position 400 where the stretchable display is not stretched are arranged in the first direction with the first space S1. The first space S1 may be smaller than the second S2. Accordingly, because the pixel density in the area where the stretchable display is not stretched is large compared to that in the area where the stretchable display is stretched, the image quality in the area where the stretchable display is not stretched can be improved.

Furthermore, the pixel islands 20 in the first portion 100 may be arranged adjacent to each other in order to maximize the image quality in the area where the stretchable display is not stretched. That is, the value of the first space S1 may be 0 μm.

FIG. 9 shows another aspect of the arrangement of the pixel islands 20 in the stretchable display 2 according to the present disclosure, which is suitable for attaching to the display device of FIG. 7. The arrangement of the pixel islands 20 shown in FIG. 9 is different from that shown in FIG. 8 in the point that the third portion 300 is provided between the first portion 100 and the second portion 200. The pixel islands 20 in the third portion 300 may be arranged in the first direction with the third space S3 that is intermediate between the first space S1 and the second space S2. Accordingly, the difference in image quality between the image displayed in the first portion 100 and the image displayed in the second portion 200, in other words, the boundary of image quality between the first portion 100 and the second portion 200 can be obscured.

As shown in FIG. 9, the second space S2 may be larger than the first space S1 and the third space S3 may vary so as to gradually increase from the first portion 100 toward the second portion 200. Gradually varying the third space S3 can further effectively obscure the difference in image quality between the image displayed in the first portion 100 and the image displayed in the second portion 200. In other words, the sharp boundary of image quality between the first portion 100 and the second portion 200 can be eliminated.

The shape of the object used as the display device is not limited to the shape shown in FIG. 7. It could be understood that the stretchable display according to the present disclosure may be effectively applicable as long as the object to be a display device has a shape including a portion where the high image quality is required (for example, a main image displaying surface) and a portion where the high stretchability is required (for example, the edge of the object) .

FIG. 10 and FIG. 11 show another aspect of the method of manufacturing the display device according to the present disclosure. FIG. 10 shows the arrangement configuration of the pixel islands 20 before the stretchable display 3 is attached to the object to be a display device, and FIG. 11 (b) shows the arrangement configuration of the pixel islands 20 after the stretchable display 3 is attached to the object.

As can be seen from Fig. 11 (a) , the display device has a truncated cone shape, and the circumference increases from top to bottom. The object may be a cone shape or a truncated cone shape, and the stretchable display may be attached to the side surface of the cone or the truncated cone. Therefore, when attaching the stretchable display to the side surface of the truncated cone shown in FIG. 11 (a) , the stretching rate of the stretchable display may increase from top to bottom.

In the display device having the shape as shown in FIG. 11, the upper position of the image displaying surface is designated as a first position 500 of the object, and the lower position of the image displaying surface is designated as the second position 550 of the object. In this case, the method of manufacturing the display device attaching the stretchable display of the present disclosure to the object comprises: aligning the first portion 600 of the stretchable display 3 with the first position 500 of the object; and aligning the second portion 700 of the stretchable display 3 with the second position 550 of the object. The stretching rate in the second portion 700 of the stretchable display may be larger than that in the first portion 600 of the stretchable display, and as shown in FIG. 10, the second space S5 between the pixel islands 20 in the second portion 700 may be smaller than the first space S4 between the pixel islands 20 in the first portion 600.

FIG. 11 shows the display device after the stretchable display 3 is attached to the object, wherein the second portion 700 is largely stretched compared to the first portion 600. Specifically, the first portion 600 is stretched in the left and right directions with a relatively small stretching rate, and thus the pixel islands 20 in the first portion 600 are arranged with the fourth space S6. On the other hand, the second portion 700 is stretched in the left and right directions with a relatively large stretching rate, but the second space S5 before stretching is set smaller than the first space S4 before stretching, thus the pixel islands 20 in the second portion 700 can be arranged with the fourth space S6.

Furthermore, also in portions not shown in FIGS. 10 and 11 other than the first portion 600 and the second portion 700, spaces therein before stretching are designed depending on their respective stretching rate such that the all pixel islands 20 are arranged with the fourth space S6 after the stretchable display is stretched. As a result, after the stretchable display 3 is attached to the side surface of the object in the shape of truncated cone, the pixel islands 20 can be uniformly arranged with the fourth space S6. Therefore, the pixel density becomes homogeneous in the whole stretchable display, the unevenness of the image quality can be eliminated, and as a result, the image quality can be improved as the whole stretchable display.

The shape of the object used as the display device is not limited to the shape shown in FIG. 11. It could be understood that the stretchable display according to the present disclosure may be effectively applicable as long as the object to be a display device has a shape wherein the stretchable display needs to be stretched with different stretching rate depending on the position of the object.

DESCRIPTION OF REFERENCE NUMERALS

1: Stretchable display

2: Stretchable display

3: Stretchable display

10: Substrate

20: Pixel island

30: Pixel substrate

32: Pixel substrate layer

40: Thin film transistor

50: Planarization layer

60: Pixel

70: Thin film encapsulation layer

80: Wiring layer

90: Overcoat layer

100: First portion

200: Second portion

300: Third portion

400: First position

450: Second position

500: First positon

550: Second position

600: First portion

700: Second portion

800: First support substrate

900: Second support substrate

Claims

A stretchable display comprising:

a substrate;

a plurality of pixel islands arranged on the substrate;

a first portion in which the pixel islands are arranged in a first direction with a first space, and

a second portion in which the pixel islands are arranged in a first direction with a second space which is different from the first space.
The stretchable display according to claim 1, further comprising a third portion located between the first portion and the second portion,

wherein the pixel islands in the third portion are arranged in the first direction with a third space which is intermediate between the first space and the second space.
The stretchable display according to claim 2,

wherein the second space is larger than the first space, and the third space gradually increase from the first portion toward the second portion.
The stretchable display according to any one of claims 1 to 3,

wherein the first space differs from the second space by at least 10%.
The stretchable display according to any one of claims 1 to 4,

wherein at least one of the first space and the second space is in the range from 10 μm to 200 μm.
The stretchable display according to any one of claims 1 to 5,

wherein each of the plurality of pixel islands comprises at least two pixels.
The stretchable display according to any one of claims 1 to 7,

wherein the substrate is a stretchable substrate.
A method of manufacturing a display device attaching the stretchable display according to any one of claims 1 to 8 to an object, comprising:

aligning the first portion with a first position of the object; and

aligning the second portion with a second position of the object.
The method of manufacturing the display device according to claim 9,

wherein the stretching rate in the second portion is larger than that in the first portion, and the second space is larger than the first space.
The method of manufacturing the display device according to claim 10,

wherein the pixel islands in the first portion are arranged adjacent to each other.
The method of manufacturing the display device according to claim 9,

wherein the stretching rate in the second portion is larger than that in the first portion, and the second space is smaller than the first space.
The method of manufacturing the display device according to claim 12,

wherein the object is in the shape of a cone or a truncated cone, and the stretchable display is attached to the side surface of the cone or the truncated cone.