CN109584728B

CN109584728B - Flexible display

Info

Publication number: CN109584728B
Application number: CN201910093187.7A
Authority: CN
Inventors: 徐明樟; 赖炎晖
Original assignee: AU Optronics Corp
Current assignee: AU Optronics Corp
Priority date: 2018-12-11
Filing date: 2019-01-30
Publication date: 2021-06-22
Anticipated expiration: 2039-01-30
Also published as: CN109584728A; TW202023089A; TWI695530B

Abstract

A flexible display includes a first substrate and a pixel definition layer. The pixel definition layer is located on the first substrate and provided with a plurality of openings. Each opening corresponds to a pixel region. The pixel definition layer has a transmittance of less than 1% and has a plurality of microstructures. Each microstructure protrudes in a direction away from the first substrate.

Description

Flexible display

Technical Field

The present invention relates to a flexible display (flexible display), and more particularly, to a flexible display with low light reflection.

Background

The flexible display has the advantages of small size, easy bending, convenient carrying and the like, so the market demand is increasingly promoted. In the conventional flexible display, in order to enable the display to be reduced in thickness and to be easily bent, the polarizing plate may be omitted. However, in a flexible display without a polarizing plate, there is a problem of metal reflection, which results in poor display effect of the display and makes viewers unable to enjoy good visual sense.

Therefore, there is still a need to provide a flexible display capable of reducing the reflection of light.

Disclosure of Invention

The present invention relates to a flexible display, and more particularly, to a flexible display with low light reflection. The pixel definition layer of the flexible display uses a material with the penetration rate less than 1 percent and has a plurality of micro structures, so the situation of metal reflection can be reduced, and the display quality is improved.

According to a first aspect of the invention, a flexible display is presented. The flexible display comprises a first substrate and a pixel definition layer. The pixel definition layer is located on the first substrate and provided with a plurality of openings. Each opening corresponds to a pixel region. The pixel definition layer has a transmittance of less than 1% and has a plurality of microstructures. Each microstructure protrudes in a direction away from the first substrate.

In order to better understand the above and other aspects of the present invention, the following detailed description of the embodiments is made with reference to the accompanying drawings:

drawings

Fig. 1A shows a cross-sectional view of a flexible display according to an embodiment of the invention.

Fig. 1B shows a schematic view of the flexible display of fig. 1A after bending.

Fig. 2A shows a cross-sectional view of a stacked structure of a flexible display according to an embodiment of the invention.

Fig. 2B shows a cross-sectional view of a stacked structure of a flexible display according to a further embodiment of the invention.

Fig. 3A shows a top view of a stacked structure of a flexible display according to an embodiment of the invention.

Fig. 3B shows a top view of a stacked structure of a flexible display according to yet another embodiment of the present invention.

Fig. 4A shows an enlarged cross-sectional view of a microstructure of a flexible display according to an embodiment of the invention.

Fig. 4B shows an enlarged cross-sectional view of a microstructure of a flexible display according to yet another embodiment of the invention.

Fig. 4C shows an enlarged cross-sectional view of a microstructure of a flexible display according to yet another embodiment of the invention.

Fig. 4D shows an enlarged cross-sectional view of a microstructure of a flexible display according to yet another embodiment of the invention.

Fig. 4E shows an enlarged cross-sectional view of a microstructure of a flexible display according to yet another embodiment of the invention.

Fig. 5A shows a cross-sectional view of a stacked structure of a flexible display according to a further embodiment of the invention.

Fig. 5B shows a cross-sectional view of a stacked structure of a flexible display according to a further embodiment of the invention.

Fig. 6A shows an oblique view of a stacked structure of a flexible display according to an embodiment of the invention.

Fig. 6B shows an oblique view of a stacked structure of a flexible display according to yet another embodiment of the present invention.

Fig. 7A shows a cross-sectional view of a stacked structure of a flexible display according to a further embodiment of the invention.

Fig. 7B shows a cross-sectional view of a stacked structure of a flexible display according to a further embodiment of the invention.

Fig. 8A shows a top view of a stacked structure of a flexible display according to an embodiment of the invention.

Fig. 8B shows a top view of a stacked structure of a flexible display according to yet another embodiment of the present invention.

Description of reference numerals:

2: flexible display

5: base film

10: laminated structure

15: covering plate

100A, 100B, 200A, 200B, 300A, 300B: laminated structure

101. 102, 103, 104, 105, 141, 161, 171, 181, 221, 231, 241, 251, 271, 341, 351, 361, 371, 421, 431, 441, 451, 461, 471, 541, 561, 571, 621, 631, 641, 661, 671: micro-structure

110: first substrate

110a, 111 a: upper surface of

111: flexible substrate

112: buffer layer

114: interlayer dielectric layer

110 s: switch unit

115: active layer

117: grid electrode

120. 220, 420, 620: planarization layer

130. 230, 430, 630: second electrode

140. 240, 340, 440, 540, 640: pixel definition layer

150. 250, 350, 450: light emitting element

160. 360, 460, 560, 660: spacer

170. 270, 370, 470, 570, 670: a first electrode

180: light shielding layer

184: hole(s)

190. 290, 390, 490, 590, 690: opening of the container

192: pixel region

1131: a first insulating layer

1132: a second insulating layer

1161: drain electrode

1162: source electrode

1181: drain electrode

1182: grid electrode

1183: source electrode

A. A': arrow head

D₁、D₂、D₃、D₄: distance between two adjacent plates

L₁、L₂、L₃、L₄: height

R, G, B: pixel

R₀、R₁、R₂、R₃: radius of

W₁、W₃、W₄: width of

Detailed Description

The present description provides various examples to illustrate the technical features of various embodiments of the present invention. The configuration of the elements in the embodiments is for illustration and not for limitation. And the reference numerals in the embodiments are partially repeated, so that the relevance between different embodiments is not intended for the sake of simplifying the description.

The flexible display has the pixel definition layer with the transmittance of less than 1 percent, and has a plurality of micro structures, so that the flexible display has lower reflectivity, the metal reflection condition in the display can be relieved, and the display quality is improved.

Fig. 1A shows a cross-sectional view of a flexible display 2 according to an embodiment of the invention.

Referring to fig. 1A, the flexible display 2 includes a substrate film 5, a stacked structure 10, and a cover plate 15. The laminated structure 10 is located on the base film 5 and the cover plate 15 is located on the laminated structure 10. That is, the laminated structure 10 is located between the base film 5 and the cover plate 15. The base film 5 may be formed of a polymer (e.g., PET, PI polyimide …, etc.). The laminated structure 10 may be a light emitting device array substrate (described in detail later). The cover plate 15 can be a glass plate or a plastic cover (material: PC, PET, PI …, etc.), and its top surface can be used as the observation surface. The flexible display 2 may be made of a bendable material, for example, bendable in the directions of arrows a and a', so that the user can carry the display conveniently.

Fig. 1B shows a schematic view of the flexible display 2 of fig. 1A after bending.

Referring to fig. 1B, after the flexible display 2 of fig. 1A is bent in the directions of arrows a and a', the bent curvature radius R₀May be less than 4 mm, for example 2 to 3 mm.

In the flexible display 2 of the present invention, the polarizing plate is not additionally disposed between the base film 5 and the cover plate 15, but the optical effect of the polarizing plate is directly replaced by the optical design in the laminated structure 10. Therefore, compared to the comparative example (the bending curvature radius is 4 mm, for example) with both the polarizer and the laminated structure between the substrate film and the cover plate, the flexible display 2 of the present invention has a smaller thickness, is easier to bend, is more portable, and still has good display quality (for example, the problem of metal reflection is improved by the optical design in the laminated structure 10).

Fig. 2A shows a cross-sectional view of a layered structure 100A of the flexible display 2 according to an embodiment of the invention.

Referring to fig. 2A, a partial enlarged view of an embodiment of the stacked structure 10 corresponding to the flexible display 2 shown in fig. 1 is shown. In the present embodiment, the stacked structure 100A of the flexible display 2 may include a first substrate 110, a planarization layer 120, a second electrode 130, a pixel defining layer 140, a plurality of light emitting elements 150 (only one is shown in fig. 2A), a spacer 160, a first electrode 170, and a light shielding layer 180. The first substrate 110 has an upper surface 110a, wherein the planarization layer 120, the second electrode 130, the pixel defining layer 140, the light emitting device 150, the spacer 160, the first electrode 170, and the light shielding layer 180 may be sequentially stacked on the upper surface 110a of the first substrate 110.

In one embodiment, the first substrate 110 may be a multi-layer composite structure. For example, the first substrate 110 may include a flexible (soft) substrate 111, a buffer layer 112, a first insulating layer 1131, a second insulating layer 1132, an interlayer dielectric layer 114, and a switch unit 110 s. The buffer layer 112, the first insulating layer 1131, the second insulating layer 1132 and the interlayer dielectric layer 114 may be sequentially stacked on the upper surface 111a of the flexible substrate 111 along a normal direction (e.g., a Z-axis direction) of the upper surface 111a of the flexible substrate 111. The switch unit 110s may include an active layer 115, a drain 1161, a source 1162, a gate 117, a drain electrode 1181, a gate electrode 1182, and a source electrode 1183. In the present embodiment, the active layer 115, the drain 1161 and the source 1162 may be formed on the same plane (e.g., on the upper surface of the buffer layer 112) and covered by the first insulating layer 1131. The gate 117 may be formed on an upper surface of the first insulating layer 1131 and covered by the second insulating layer 1132. The flexible substrate 111 may be made of polyimide. The buffer layer 112 and the interlayer dielectric layer 114 may be made of inorganic dielectric materials. The first insulating layer 1131 and the second insulating layer 1132 may be made of oxide, such as silicon oxide. The material of the active layer 115 may include an oxide semiconductor or polysilicon, and the oxide semiconductor may be a mixture of oxides of elements of groups 2 to 4 of the periodic table, such as Indium Gallium Zinc Oxide (IGZO), Indium Zinc Tin Oxide (IZTO), Indium Gallium Tin Oxide (IGTO), Indium Zinc Oxide (IZO), Indium Gallium Oxide (IGO), Zinc Tin Oxide (ZTO), and tin oxide (SnO). The drain electrode 1181, the gate electrode 1182, and the source electrode 1183 may be made of a metal material.

In the present embodiment, the pixel defining layer 140 is disposed on the first substrate 110, for example, on the upper surface of the planarization layer 120. The pixel defining layer 140 has low transmittance and reflectance and may be made of Black Matrix photoresist (Black Matrix Resist) such as acryl resin material. In one embodiment, the transmittance of the pixel defining layer 140 is less than 1%. That is, the material of the pixel defining layer 140 has low transmittance and may be a dark material. The pixel defining layer 140 has a plurality of micro-structures 141, and each micro-structure 141 protrudes away from the first substrate 110. In the normal direction of the upper surface 110a of the first substrate 110, the pixel defining layer 140 may overlap the drain electrode 1181, the gate electrode 1182 and the source electrode 1183 or a signal line electrically connected to the above electrodes. When the ambient light irradiates the inside of the stacked structure 100A and meets the metal elements (such as the drain electrode 1181, the gate electrode 1182, the source electrode 1183 and the signal line) to generate reflected light, the pixel defining layer 140 having a plurality of microstructures and having a low transmittance may absorb the reflected light at different angles, and may prevent the light from being too concentrated, thereby reducing the influence of the ambient light on the display quality of the image. The pixel defining layer 140 may form a plurality of openings 190 (shown in fig. 3A), and each opening 190 may correspond to one pixel region 192 or one sub-pixel region. The light emitting elements 150 respectively correspond to the openings 190 formed in the pixel defining layer 140 and are electrically connected to the first electrode 170 and the second electrode 130. The first electrode 170 covers the surfaces of the pixel defining layer 140, the light emitting element 150 and the spacer 160, and is conformal with the pixel defining layer 140, the light emitting element 150 and the spacer 160. That is, the first electrode 170 conforms to the topography of the pixel defining layer 140, the light emitting element 150 and the spacers 160, and has a corresponding shape or shape. The second electrode 130 may be formed on the upper surface of the planarization layer 120 and pass through the planarization layer 120 to electrically connect and contact the switch unit 110s (e.g., contact the drain electrode 1181). The light emitting element 150 is located between the first electrode 170 and the second electrode 130, and is electrically connected to the first electrode 170 and the second electrode 130. The light-emitting element 150 is, for example, an organic light-emitting diode. The first electrode 170 is, for example, a cathode, and the second electrode 130 is, for example, an anode.

In one embodiment, the number of spacers 160 is greater than 1 (fig. 2A only illustrates 1 spacer). The plurality of spacers 160 may be spaced apart from each other. The spacers 160 are disposed on the pixel defining layer 140, and may be made of Black Matrix photoresist (Black Matrix Resist), such as acryl resin material, and have low transmittance and reflectance. For example, the penetration rate of the spacers 160 is less than 1%. Also, the spacers 160 include microstructures 161. Each of the microstructures 161 may protrude in a direction away from the first substrate 110. The number of microstructures 161 may be equal to 1 or greater than 1. The top of the microstructure 161 of the spacer 160 has a first distance D from the upper surface 110a of the first substrate 110₁The microstructure 141 of the pixel defining layer 140 has a second distance D from the upper surface 110a of the first substrate 110₂And a first distance D₁Greater than the second distance D₂. Similar to the optical effect of the pixel defining layer 140, when the ambient light irradiates the interior of the stacked structure 100A, the ambient light encounters the metal elements (such as the drain electrode 1181, the gate electrode 1182, and the source electrode 11)83 and signal lines), the spacers with low transmittance and microstructures can absorb the reflected light at different angles and avoid the light from being too concentrated, so as to further reduce the influence of the ambient light on the display quality of the image compared to the optical design with the pixel definition layer 140 (e.g. using the material with low transmittance and the microstructures 141) and the spacers without the above optical design.

In one embodiment, the first electrode 170 covers the spacer 160 and the pixel defining layer 140, and has a plurality of microstructures 171. The portion of the first electrode 170 covering the light emitting element 150 does not have the microstructure 171. The microstructures 171 of a portion of the first electrode 170 have an outer shape corresponding to the microstructures 141 of the pixel defining layer 140, and the microstructures 171 of a portion of the first electrode 170 have an outer shape corresponding to the microstructures 161 of the spacers 160. A third distance D is provided between the top portion of the first electrode 170 corresponding to the microstructure 161 of the spacer 160 and the upper surface 110a of the first substrate 110₃A fourth distance D is provided between a top portion of the first electrode 170 corresponding to the microstructure 141 of the pixel defining layer 140 and the upper surface 110a of the first substrate 110₄A third distance D₃Is greater than the fourth distance D₄。

In one embodiment, the light shielding layer 180 is disposed on the first electrode 170 and has a hole 184 corresponding to the light emitting device 150. The light-shielding layer 180 has low reflectivity and transmittance, and is made of Black Matrix photoresist (Black Matrix Resist) such as acryl resin material, for example, the transmittance is less than 1%. Compared to the embodiment that only has the optical design of the pixel defining layer 140 (e.g., uses the material with low transmittance and has the microstructure 141) and the optical design of the spacer 160 (e.g., uses the material with low transmittance and has the microstructure 161) but does not have the optical design of the light shielding layer 180 (e.g., uses the material with low transmittance), the low transmittance material of the light shielding layer 180 in the embodiment can further reduce the influence of the ambient light on the display quality of the image. In other embodiments, the stacked structure 100A of the present invention may not have the light-shielding layer 180, and the first electrode 170 may not be covered by the light-shielding layer 180. The plurality of microstructures (e.g., between the

microstructures

141, 161, 171) may have partially the same or partially different dimensions, such as width and height.

Fig. 2B shows a cross-sectional view of a layered structure 100B of a flexible display 2 according to yet another embodiment of the invention. The structure of the stacked structure 100B is similar to the structure of the stacked structure 100A, except that the light-shielding layer 180 has a microstructure 181, the planarization layer 220 has a microstructure 221, the second electrode 230 has a microstructure 231, the light-emitting element 250 has a microstructure 251, and the arrangement of the microstructure 241 of the pixel defining layer 240 and the microstructure 271 of the first electrode 270 are different from the arrangement of the microstructure 141 of the pixel defining layer 140 and the microstructure 171 of the first electrode 170, respectively, and the other repeated points are not described in detail herein.

Referring to fig. 2B, the upper surface of the light-shielding layer 180 has a plurality of micro-structures 181, and the upper surface of the planarization layer 220 has a plurality of micro-structures 221. Each of the micro-structures 181 of the light-shielding layer 180 and each of the micro-structures 221 of the planarization layer 220 protrude away from the first substrate 110. The upper surface of the second electrode 230 also has the microstructure 231, that is, the microstructure 231 of the second electrode 230 directly contacts the light emitting device 250. Compared to the pixel defining layer 140 of fig. 2A, the pixel defining layer 240 has a smaller area on the planarization layer 220, and a portion of the planarization layer 220 can directly contact the first electrode 270. In the area where the first electrode 270 directly covers the planarization layer 220, the first electrode 270 may conform to the topography of the planarization layer 220, such that the micro-structures 271 of the first electrode 270 and the micro-structures 221 of the planarization layer 220 may have corresponding shapes. Also, a portion of the microstructure 271 of the first electrode 270 is located on the upper surface of the light emitting unit 150. Compared to the stacked structure 100A of fig. 2A, since the stacked structure 100B has more microstructures, for example, the number of the microstructures 271 of the first electrode 270 is larger, the light-shielding layer 180 has the microstructures 181, the planarization layer 220 has the microstructures 221, and the second electrode 230 also has the microstructures 231, the reflected light caused by the ambient light encountering the metal element can be better dispersed, the observer can be prevented from feeling more concentrated light, and the display quality of the image is better facilitated.

In fig. 2A and 2B, the

microstructures

141, 161, 171, 181, 221, 231, and 271 are illustrated as semi-spherical. However, the invention is not limited thereto, and the microstructure may be any geometric shape (for example, a sphere, a cone, a cylinder, a triangular cone, a triangular prism, a rectangular parallelepiped, a cube, or a trapezoidal cylinder), as long as the purpose of dispersing light can be achieved.

Fig. 3A illustrates a top view of a laminated structure 100A of the flexible display 2 according to an embodiment of the present invention, exemplarily illustrating a schematic diagram of relative positions of the micro structures in fig. 2A (omitting the light shielding layer 180 and the first electrode 170).

Referring to fig. 3A, the pixel defining layer 140 has a microstructure 141, and the spacer 160 has a microstructure 161. The pixel defining layer 140 forms a plurality of openings 190, and each opening 190 corresponds to one pixel region 192 (e.g., a red pixel R, a green pixel G, and a blue pixel B). The spacer 160 is disposed on the pixel defining layer 140. The

microstructures

141 and 161 may be round sphere, cylindrical or conical, respectively.

Fig. 3B illustrates a top view of a laminated structure 100B of a flexible display 2 according to yet another embodiment of the present invention, exemplarily illustrating a schematic diagram of relative positions of the micro-structures in fig. 2B (omitting the light shielding layer 180 and the first electrode 170).

Referring to fig. 3B, the pixel defining layer 240 has a microstructure 241, the spacer 160 has a microstructure 161, and the first electrode 270 has a microstructure 271. The pixel defining layer 240 forms a plurality of openings 290, and each opening 290 corresponds to one pixel region (e.g., a red pixel R, a green pixel G, and a blue pixel B). The spacers 160 are disposed on the pixel defining layer 240. The microstructure 271 of the first electrode 270 may correspond to the opening 290, for example, to cover the light emitting element 150 (shown in fig. 2B). The

microstructures

241, 161, and 271 may be spherical, cylindrical, or conical, respectively.

Fig. 4A shows an enlarged cross-sectional view of a microstructure 101 of a flexible display according to an embodiment of the invention. Any of the above-described microstructures (e.g., microstructure 141, microstructure),161. 181, 221, 231, 241, 271) can be applied to the micro-structure 101, and can be a spherical ball type or a semi-spherical ball type. Radius R of microstructure 101₁And may be between 0.1 microns and 10 microns.

Fig. 4B shows an enlarged cross-sectional view of a microstructure 102 of a flexible display according to yet another embodiment of the invention. The shape of any of the above-mentioned microstructures (e.g.,

microstructures

141, 161, 181, 221, 231, 241, 271) can be applied to the microstructure 102, and can be cylindrical. Radius R of microstructure 102₂Can be between 0.1 and 10 microns, height L₁And may be 0.1 to 5 microns.

Fig. 4C shows an enlarged cross-sectional view of a microstructure 103 of a flexible display according to yet another embodiment of the invention. The shape of any of the above-described microstructures (e.g.,

microstructures

141, 161, 181, 221, 231, 241, 271) can be applied to the microstructure 103, and can be a cone shape. Radius R of microstructure 103₃Can be between 0.1 and 10 microns, height L₂And may be 0.1 to 5 microns.

Fig. 4D shows an enlarged cross-sectional view of a microstructure 104 of a flexible display according to yet another embodiment of the invention. The shape of any of the above-mentioned microstructures (e.g.,

microstructures

141, 161, 181, 221, 231, 241, 271) can be applied to the microstructure 104, and can be a triangular pyramid. Width W of microstructure 104₁Can be between 0.1 and 10 microns, height L₃And may be 0.1 to 5 microns.

Fig. 4E shows an enlarged cross-sectional view of a microstructure 105 of a flexible display according to yet another embodiment of the invention. The shape of any of the above-described microstructures (e.g.,

microstructures

141, 161, 181, 221, 231, 241, 271) can be applied to the microstructure 105, and can be a trapezoidal pillar (i.e., a trapezoid in the cross-sectional view formed by the X-axis and the Z-axis). The microstructure 105 has a top width W at a top surface remote from the first substrate 110₃Having a bottom width W near the bottom surface of the first substrate 110₄. Width W of bottom₄Greater than the top width W₃. Width W of the top₃Can be between 0.1 and 10 microns, and a bottom width W₄Can be between 0.1 micron and 20 microns. Vertical height L between top and bottom surfaces of microstructure 105₄And may be 0.1 to 5 microns.

Fig. 5A shows a cross-sectional view of a layered structure 200A of a flexible display 2 according to yet another embodiment of the invention. The structure of the stacked structure 200A is similar to the stacked structure 100A, except that no light-shielding layer is disposed, and the shapes of the microstructure 341 of the pixel defining layer 340, the microstructure 361 of the spacer 360 and the microstructure 371 of the first electrode 370 are different from the shapes of the microstructure 141 of the pixel defining layer 140, the microstructure 161 of the spacer 160 and the microstructure 171 of the first electrode 170, respectively, and the other repeated points are not described in detail herein.

Referring to fig. 5A, the micro-structures 341 of the pixel defining layer 340 and the micro-structures 361 of the spacers 360 may have a conical shape (as in the embodiment of fig. 4C) or a triangular conical shape (as in the embodiment of fig. 4D). The microstructure 371 of the first electrode 370 then conforms to the

microstructure

341 or 361. When

microstructures

341 and 361 are conical, the dimension range can be the same as that of microstructure 103 in FIG. 4C. When

microstructures

341 and 361 are triangular pyramids, the size range can be the same as that of microstructure 104 in FIG. 4D.

Fig. 5B shows a cross-sectional view of a layered structure 200B of a flexible display 2 according to yet another embodiment of the invention. The structure of the stacked structure 200B is similar to the stacked structure 100B, except that no light-shielding layer is provided, and the shapes of the microstructure 421 of the planar layer 420, the microstructure 351 of the light-emitting element 350, the microstructure 431 of the second electrode 430, the microstructure 441 of the pixel defining layer 440, the microstructure 461 of the spacer 460, and the microstructure 471 of the first electrode 470 are different from the shapes of the microstructure 221 of the planar layer 220, the microstructure 251 of the light-emitting element 250, the microstructure 231 of the second electrode 230, the microstructure 241 of the pixel defining layer 240, the microstructure 161 of the spacer 160, and the microstructure 271 of the first electrode 270, respectively, and the other repeated points are not described in detail herein.

Referring to fig. 5B, the microstructure 421 of the planarization layer 420, the microstructure 351 of the light emitting device 350, the microstructure 431 of the second electrode 430, the microstructure 441 of the pixel definition layer 440, and the microstructure 461 of the spacer 460 may have a conical shape (as in the embodiment of fig. 4C) or a triangular cone shape (as in the embodiment of fig. 4D). The micro-structure 471 of the first electrode 470 is conformal to the micro-structure 351, 441 or 461. When the microstructure 421 of the planarization layer 420, the microstructure 431 of the second electrode 430, the microstructure 441 of the pixel definition layer 440, and the microstructure 461 of the spacer 460 are conical, the dimension range can be the same as the microstructure 103 of fig. 4C. When the microstructure 421 of the planarization layer 420, the microstructure 431 of the second electrode 430, the microstructure 441 of the pixel definition layer 440, and the microstructure 461 of the spacer 460 are triangular cones, the dimension ranges can be the same as the microstructure 104 of fig. 4D.

Fig. 6A shows an oblique view of a stacked structure 200A of the flexible display 2 according to an embodiment of the invention, exemplarily showing a schematic diagram of the relative positions of the micro-structures in fig. 5A (omitting the first electrode 370).

Referring to fig. 6A, the pixel defining layer 340 has a microstructure 341, and the spacer 360 has a microstructure 361. The pixel defining layer 340 forms a plurality of openings 390, and each opening 390 corresponds to a pixel region (e.g., a red pixel R, a green pixel G, and a blue pixel B). The spacer 360 is disposed on the pixel defining layer 340.

Microstructures

341 and 361 may be triangular cones or triangular columns, respectively.

Fig. 6B shows an oblique view of a layered structure 200B of the flexible display 2 according to yet another embodiment of the invention, exemplarily showing a schematic view of the relative positions of the micro-structures in fig. 5B.

Referring to fig. 6B, the pixel defining layer 440 has a microstructure 441, the spacer 460 has a microstructure 461, and the first electrode 470 has a microstructure 471. The pixel defining layer 440 forms a plurality of openings 490, each opening 490 corresponding to a pixel region (e.g., a red pixel R, a green pixel G, and a blue pixel B). The spacers 460 are disposed on the pixel defining layer 440. The micro-structure 471 of the first electrode 470 may correspond to the opening 490, for example, covering the light emitting element 150 (shown in fig. 5B).

Microstructures

441, 461, and 471 can be triangular cones or triangular columns, respectively.

Fig. 7A shows a cross-sectional view of a layered structure 300A of a flexible display 2 according to yet another embodiment of the invention. The structure of the stacked structure 300A is similar to the stacked structure 100A, except that no light-shielding layer is disposed, and the shapes of the microstructure 541 of the pixel defining layer 540, the microstructure 561 of the spacer 560, and the microstructure 571 of the first electrode 570 are different from the shapes of the microstructure 141 of the pixel defining layer 140, the microstructure 161 of the spacer 160, and the microstructure 171 of the first electrode 170, respectively, and the other repeated points are not described in detail herein.

Referring to fig. 7A, the microstructures 541 of the pixel defining layer 540 and the microstructures 561 of the spacers 560 may have a trapezoidal shape. The microstructures 571 of the first electrode 570 are conformal to the

microstructures

541 or 561.

Fig. 7B shows a cross-sectional view of a layered structure 300B of a flexible display 2 according to a further embodiment of the invention. The structure of the stacked structure 300B is similar to the stacked structure 100B, except that no light-shielding layer is provided, and the shapes of the microstructure 621 of the planar layer 620, the microstructure 451 of the light-emitting device 450, the microstructure 631 of the second electrode 630, the microstructure 641 of the pixel defining layer 640, the microstructure 661 of the spacer 660, and the microstructure 671 of the first electrode 670 are different from the shapes of the microstructure 221 of the planar layer 220, the microstructure 251 of the light-emitting device 250, the microstructure 231 of the second electrode 230, the microstructure 241 of the pixel defining layer 240, the microstructure 261 of the spacer 260, and the microstructure 271 of the first electrode 270, respectively, and the other repetition points are not described in detail herein.

Referring to fig. 7B, the microstructure 621 of the planarization layer 620, the microstructure 451 of the light emitting device 450, the microstructure 631 of the second electrode 630, the microstructure 661 of the spacer 660, and the microstructure 671 of the first electrode 670 may be trapezoidal columns having a trapezoidal shape in the cross-sectional view formed by the X-axis and the Z-axis. Micro-structure 671 of first electrode 670 conforms to a portion of micro-structure 621 and a portion of micro-structure 661.

Fig. 8A shows a top view of a stacked structure 300A of the flexible display 2 according to an embodiment of the invention, exemplarily showing a schematic diagram of the relative positions of the micro-structures in fig. 7A (omitting the first electrode 570).

Referring to fig. 8A, the pixel defining layer 540 has microstructures 541, and the spacers 560 have microstructures 561. The pixel defining layer 540 forms a plurality of openings 590, and each opening 590 corresponds to a pixel region or a sub-pixel region (e.g., a red pixel R, a green pixel G, and a blue pixel B). The spacers 560 are disposed on the pixel defining layer 540. The

microstructures

541 and 561 may be respectively a trapezoidal pillar, a rectangular parallelepiped, or a geometric pillar with a rectangular bottom surface.

Fig. 8B shows a top view of a stacked structure 300B of the flexible display 2 according to yet another embodiment of the invention, exemplarily showing a schematic view of the relative positions of the micro-structures in fig. 7B.

Referring to fig. 8B, the pixel defining layer 640 has a microstructure 641, the spacer 660 has a microstructure 661, and the first electrode 670 has a microstructure 671. The pixel defining layer 640 forms a plurality of openings 690, and each opening 690 corresponds to a pixel region (e.g., a red pixel R, a green pixel G, and a blue pixel B). The spacers 660 are disposed on the pixel defining layer 640. The microstructure 671 of the first electrode 670 may correspond to the opening 690, for example, to cover the light emitting element 150 (shown in fig. 7B). The

microstructures

641, 661, and 671 may be trapezoidal, rectangular, or a geometric cone or a geometric cylinder with a rectangular bottom surface.

In the above embodiments, the shape of each microstructure of the pixel definition layer may be a sphere, a cylinder, a cone, a pyramid, or a trapezoid, respectively, but the invention is not limited thereto.

Please refer to the following table one, which shows the bending results and optical characteristics of experimental example 1 and comparative example 1. Experimental example 1 is a flexible display 2 according to an embodiment of the present invention (shown in fig. 1A without a polarizing plate between the cover plate 15 and the base film 5). Comparative example 1 is a flexible display having a polarizing plate between the cover plate 15 and the base film 5. The thickness of comparative example 1 was larger than that of experimental example 1 because it had at least one more polarizing plate.

Watch 1

In table one, the flexible display of comparative example 1 and the flexible display of experimental example 1 were subjected to bending tests at different radii of curvature (2 mm, 3 mm, and 4 mm), respectively, and strain (strain) was calculated in a simulation manner. With a smaller radius of curvature, the more strain the flexible display under test is subjected to. In comparative example 1, the strains were all greater than 1% under bending with different radii of curvature, and the strains in inverse experimental example 1 were all less than 1%. It can be seen that experimental example 1 is more flexible than comparative example, does not undergo much strain, and has a lower probability of cracking and breaking. Also, the reflectance of experimental example 1 was only slightly higher than that of comparative example 1, and still had quite good anti-reflection optical characteristics.

The invention provides a flexible display, wherein the penetration rate of a pixel definition layer is less than 1%, and the flexible display is provided with a plurality of microstructures. Therefore, when the ambient light irradiates the interior of the flexible display and meets the metal element to generate the reflected light, the pixel definition layer with low transmittance and a plurality of microstructures can absorb the reflected light at different angles, and the design of the microstructures can avoid the light from being too concentrated, thereby reducing the influence of the ambient light on the display quality of the picture. In addition, since the pixel defining layer has the optical characteristics, the flexible display of the present invention can replace the polarizing plate, so that the flexible display of the present invention can have good optical characteristics (e.g., low reflectivity) without the polarizing plate, can reduce the thickness of the flexible display, and can be bent more easily without being damaged.

While the present invention has been described with reference to the above embodiments, it is not intended to be limited thereto. It will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention is subject to the claims.

Claims

1. A flexible display, comprising:

a first substrate including a drain electrode, a gate electrode and a source electrode;

a pixel defining layer on the first substrate and having a plurality of openings, each opening corresponding to a pixel region, wherein the pixel defining layer has a transmittance of less than 1% and has a plurality of microstructures, each microstructure protruding in a direction away from the first substrate; and

a first electrode on the pixel definition layer, wherein the first electrode has a plurality of microstructures, and a portion of the microstructures of the first electrode have shapes corresponding to the microstructures of the pixel definition layer;

the pixel defining layer can be overlapped with the drain electrode, the grid electrode and the source electrode.

2. The flexible display of claim 1, further comprising a plurality of light emitting elements, wherein the light emitting elements are disposed corresponding to the openings respectively, and each of the light emitting elements is electrically connected to the first electrode.

3. The flexible display of claim 2, wherein the microstructures of the portion of the first electrode are located on the light emitting elements.

4. The flexible display of claim 2, further comprising a second electrode on the first substrate, wherein each of the light emitting elements is disposed between the first electrode and the second electrode, and each of the light emitting elements is electrically connected to the second electrode.

5. The flexible display of claim 4, wherein the second electrode has a plurality of microstructures, the microstructures of the second electrode protrude away from the first substrate, and a portion of the microstructures of the second electrode underlie the light-emitting elements.

6. The flexible display of claim 2, further comprising a light-shielding layer disposed over the first electrode and having holes corresponding to the light-emitting elements, wherein the light-shielding layer has a transmittance of less than 1% and has a plurality of microstructures, and the microstructures of the light-shielding layer protrude away from the first substrate.

7. The flexible display of claim 1, further comprising a spacer on the pixel defining layer, the spacer having a transmittance of less than 1% and at least one microstructure, the at least one microstructure of the spacer protruding away from the first substrate.

8. The flexible display of claim 1, further comprising a planarization layer disposed between the first substrate and the pixel defining layer, the planarization layer having a transmittance of less than 1%.

9. The flexible display of claim 8, wherein the planar layer has a plurality of microstructures, each of the microstructures of the planar layer protruding away from the first substrate.

10. The flexible display of claim 1, wherein each of the microstructures of the pixel definition layer has a shape of a sphere, a cylinder, a cone, a pyramid, a trapezoid, or any combination thereof.