Patent Grant
9214640
This application claims priority to and the benefit of Korean Patent Application No. 2012-0155873, filed on Dec. 28, 2012, the disclosure of which is incorporated herein by reference in its entirety.
1. Field of the Invention
The present invention relates to a flexible display device, and more particularly to a narrow bezel or a bezel-free flexible display device and a method of manufacturing the same.
2. Discussion of Related Art
Display devices used in monitors of computers, TVs, and cell phones include organic light emitting display devices (OLEDs) and plasma display panels (PDPs), both of which autonomously emit light, and liquid crystal display devices (LCDs) requiring a separate light source, etc.
In recent years, flexible display devices manufactured using materials exhibiting inflexibility, such as flexible materials (i.e., plastics), to display an image even when bent like paper have received attention as next-generation display devices.
Flexible display devices have been widely used in the field of applications spanning from monitors of computers and TVs to personal portable equipment, and research on flexible display devices having a large display area and a smaller volume and weight has been conducted.
Various kinds of highly complicated technology, such as wire positioning, line width setting, and signal transfer, are required to realize a narrow bezel.
Embodiment relate to a flexible display device including a flexible display substrate and a support substrate. The flexible display substrate includes a display area and a peripheral circuit area. The display area is formed with pixel elements for generating an image. The peripheral circuit area includes components to transmitting signals to the pixel elements in the display area. A support substrate is attached to the flexible display substrate to provide rigidity to the flexible display device. The support substrate includes a non-bending area, and a bending area. The bending area extends along a boundary of the peripheral circuit area and the bending area, the bending area adjacent to the non-bending area, the bending area less rigid than the non-bending area.
In one embodiment, thin film transistors are formed as the pixel elements on the flexible display substrate. The thin film transistors operate light emitting elements formed on the flexible display substrate based on the transmitted signals.
In one embodiment, the bending area is formed with a plurality of holes, a slit extending across the bending area or a half-cut channel.
In one embodiment, the half-cut channel is a hollow channel with an opening facing towards the flexible display substrate or facing away from the flexible display substrate.
In one embodiment, the flexible display device further includes a cover glass having a display region corresponding to the display area of the flexible display substrate.
In one embodiment, the flexible display substrate is bent at a substantially right angle along the bending area.
In one embodiment, the flexible display device further includes a polarizer on the flexible display substrate. The polarizer is formed with a pattern along the bending area to provide flexibility to the polarizer in the bending area.
In one embodiment, the flexible display device further includes a metal substrate interposed between the flexible display substrate and the support substrate.
In one embodiment, the flexible display device further includes an encapsulation layer extending over at least a portion of the display area and at least a portion of the peripheral circuit area.
In one embodiment, the flexible display device further includes a layer on the components for transmitting the signals in the peripheral circuit area to reduce tensile stress in the components when bending occurs in the bending area.
Embodiments also relate to a flexible display device that includes a flexible display substrate and a support substrate disposed on the flexible display substrate. The flexible display substrate has a display area and a peripheral circuit area. The display area is juxtaposed to a peripheral circuit area. A support substrate is disposed on the flexible display substrate. The support substrate has a bending pattern to provide flexibility at a bending area of the support substrate and to reduce resilient force of the flexible display device. The bending area corresponds to a boundary between the display area and the peripheral circuit area of the flexible display substrate.
In one embodiment, the bending pattern is a plurality of holes spaced apart from each other by a predetermined distance.
In one embodiment, a bending angle between the display area and the peripheral circuit area is between 70 degrees and 110 degrees.
Embodiments also relate to a multi-layered substrate structure including a first flexible substrate, and a second flexible substrate. The second flexible substrate is fixed to the first flexible substrate and is more rigid than the first flexible substrate. The second flexible substrate is formed with a bending pattern to define a bending area along which the multi-layered substrate structure is bent. An organic light emitting element is also placed on the first flexible substrate of the multi-layered substrate structure.
In one embodiment, the bending pattern is formed along a boundary between a display area and a peripheral circuit area of the second flexible substrate.
In one embodiment, the multi-layered substrate structure is formed with at least another bending pattern at an end portion of the second flexible substrate.
In one embodiment, the multi-layered substrate structure includes at least two separated display areas of the first flexible substrate. The bending pattern is formed in a boundary of the at least two separated display areas.
In one embodiment, at least one display area is placed between the bending pattern and the other bending pattern.
In one embodiment, the bending pattern includes a plurality of holes aligned along the boundary between a display area and a peripheral circuit area of the multi-layered substrate structure.
In one embodiment, the bending pattern includes a half-cut channel on one surface of the second flexible substrate facing the first flexible display substrate or facing away from the first flexible display substrate.
In one embodiment, the multi-layered substrate structure is bent at a substantially right angle along the bending area and the organic light emitting element remains substantially planar.
Embodiments also relate to a flexible display device including a flexible display substrate and a plurality of support substrate. The flexible display substrate includes a plurality of display areas. Each of the display areas formed with pixel elements for generating an image. The support substrates are more rigid than the flexible display substrate, each of the support substrate fixed to a selected portion of the flexible display substrate to maintain the selected portion of the flexible substrate in a planar shape. The flexible display substrate is bent at a bending area not fixed with the at least one support substrates.
In one embodiment, the selected portion corresponds to one of the display areas of the flexible display substrate and the bending area includes a non-display area for transmitting signals to the one of the display areas.
In one embodiment, the flexible display substrate includes a first portion fixed with a first support substrate, a second portion fixed with a second support substrate, and a third portion fixed with a third support substrate. A first bending portion is formed between the first portion and the second portion, and a second bending portion is formed between the second portion and the third portion.
In one embodiment, each of at least two adjacent support substrates has a side end, which is not perpendicular to the corresponding portion of the flexible display substrate. Instead, the side end of at least two adjacent support substrates is angled so that the gap between the two adjacent support substrates is reduced upon bending of the flexible substrate.
It is to be understood that both the foregoing general description and the following detailed description are and explanatory and are intended to provide further explanation of the invention as claimed.
The accompanying drawings, which constitute a part of this specification, illustrate various embodiments of the present invention.
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It is noted that the drawings of the present application are provided for illustrative purposes only and, as such, the drawings are not drawn to scale. In the following description, numerous specific details are set forth, such as particular structures, components, materials, dimensions, processing steps and techniques, in order to provide an understanding of the various embodiments of the present disclosure. However, it will be appreciated by one of ordinary skill in the art that the various embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known structures or processing steps have not been described in detail in order to avoid obscuring the present disclosure.
It will be understood that when an element as a layer, region or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.
It will also be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present.
Further, it will be understood that when an element is referred to as being “overlapped” with another element, one element can be positioned above the other element or below the other element. Moreover, although some of the elements are designated with numerical terms (e.g., first, second, third, etc.), it should be understood that such designations are only used to specify one element from a group of similar elements, but not to limit the element in any specific order. As such, an element designated as a first element could be termed as a second element or as third element without departing from the scope of embodiments.
An organic light emitting display device described herein includes one or more OLED elements. The OLED elements can be configured to operate in one of a top, bottom or dual emission mode, depending on the direction light exiting the OLED elements. An OLED element is classified as bottom emission mode OLED element if the light emitted from the OLED element passes through a transparent or a semi-transparent bottom electrode and substrate on which the panel was manufactured. An OLED element is classified as a top emission mode OLED element if the light emitted from the OLED element exits through a transparent or a semi-transparent top electrode. An OLED element can be classified as a dual emission mode OLED element if the light emitted from the OLED element exits through both the top and bottom electrodes to emit light on both sides of the OLED element. The components of the organic light emitting display device including, but not limited to, a thin film transistor, an anode, and a cathode as well as the structure of organic EL layer design, may be configured differently based on the aforementioned emission modes without departing from the sprit of the present invention.
A flexible display device herein refers to a display device having some degree of flexibility. The flexible display device herein is synonymous with a bendable display device, a rollable display device, an unbreakable display device, or a foldable display device. As described herein, a flexible organic light emitting display device is one example of various flexible display devices.
The flexible display device described in the present disclosure may be transparent. In the present disclosure, the terms “transparent” and “translucent” are used interchangeably to indicate property that light at least partially passes through the flexible display device such that objects behind the display device is visible. Accordingly, a transparent display device refers to a display device in which at least a part of the screen is transparent or semi-transparent so that the viewer is able to see the content displayed by the device while still being able to see the objects behind the display device in some degree.
The term “peripheral circuit area” described herein refers to an area where various circuits and wires are provide to transmit signals to the OLED. To increase the transparency of the flexible display device, non-transparent or opaque components of the display device (e.g., battery, printed circuit board, metal frame), can be disposed in the peripheral circuit area rather than in the display/non-display display areas.
The term “display area” is described herein refers to an area of the flexible display device where image is actually displayed. In case of transparent flexible display device, the display area may include both a pixel area and a non-pixel area. In such embodiment, the pixel area is configured to emit light for displaying image, while the non-pixel area is formed to be transparent so that external light can pass through the display device.
Hereinafter, various embodiments of the present invention will be described in further detail with reference to the accompanying drawings.
The flexible substrate 120 is a substrate configured to support various elements of the flexible display device 100. The flexible substrate 120 may also be referred to as a flexible substrate, a first flexible substrate, or a flexible member. When the flexible substrate 120 is formed of a plastic, the flexible substrate 120 may be referred to as a plastic film, or a plastic substrate.
The flexible substrate 120 is made of a flexible material. The flexible substrate 120 may be made of material such as a polyester-based polymer, a silicone-based polymer, an acrylic polymer, a polyolefin-based polymer, and a copolymer thereof. More particularly, the flexible substrate 120 may be made of material such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polysilane, polysiloxane, polysilazane, polycarbosilane, polyacrylate, polymethacrylate, polymethylacrylate, polyethylacrylate, polyethylmetacrylate, a cyclic olefin copolymer (COC), a cyclic olefin polymer (COP), polyethylene (PE), polypropylene (PP), polyimide (PI), polymethylmetacrylate (PMMA), polystyrene (PS), polyacetal (POM), polyether ether ketone (PEEK), polyestersulfone (PES), polytetrafluoroethylene (PTFE), polyvinylchloride (PVC), polycarbonate (PC), polyvinylidenefluoride (PVDF), a perfluoroalkyl polymer (PFA), a styrene acrylonitrile copolymer (SAN), and a combination thereof. The flexible substrate 120 can also be formed of a transparent flexible material.
The flexible substrate 120 includes a display area “A” and a peripheral circuit area “B”. The display area A of the flexible substrate 120 refers to an area for displaying image, and the peripheral circuit area B refers to an area where no image is displayed. The peripheral circuit area B of the flexible substrate 120 may be positioned at one side of the display area A of the flexible substrate 120. Since the peripheral circuit area B only contains wires and circuits and does not display any images therefrom, a protective member (e.g., housing, bezel) often covers the peripheral circuit area B. The peripheral circuit area B of the flexible substrate 120 may be formed in a polygonal shape, and the peripheral circuit area B of the flexible substrate 120 may include an area extending from one side of the display area A of the flexible substrate 120. Since the peripheral circuit area B of the flexible substrate 120 is positioned at a peripheral or edge portion of the display area A of the flexible substrate 120, the peripheral circuit area B of the flexible substrate 120 may be referred to as a peripheral area, an edge area, or a bezel area.
Such protective member is usually formed with a material having substantially more rigidity than the flexible display device 100 and limits the design of the flexible display device 100. Further, the protective member makes the display device to stand out from the surroundings, thereby making impedes immersive viewing experience to the viewers. Accordingly, it is advantageous to bend or curve the peripheral circuit area B so that the bezel area for covering the peripheral circuit area B can be reduced (i.e., narrow-bezel) or eliminated (i.e., bezel-free). However, the support film 110 has much greater rigidity than the flexible substrate 120. When the display area A is bent, stress may be formed at or near the bend area of the display unit 130, causing the display unit 130 or other components on the display unit 130 to peel off from the flexible substrate 120.
A display unit 130 may extend partially or entirely over the display area A of the flexible substrate 120. The display unit 130 is a component that actually displays an image, and may be referred to as an image display unit or display panel. In some embodiments, display unit 130 is embodied as an OLED that generates images by emitting light from one or more organic light emitting layers.
Some or all of the elements of the display device that do not emit light can be disposed at the peripheral circuit area B of the flexible substrate 120. The elements disposed at the peripheral circuit area B of the flexible substrate 120 may be connected to a drive circuit unit 170 equipped within various ICs 175 (e.g., gate driver ICs or source driver ICs), a wire 171, and a wire 165 electrically connecting the drive circuit unit 170 to the display unit 130. The wire 165 electrically connects the display unit 130 disposed at the display area A to other elements disposed at the peripheral circuit area B of the flexible substrate 120. Therefore, part of the wire 165 may be disposed within the display area A of the flexible substrate 120. The drive circuit unit 170 may be installed in the flexible substrate 120 using various techniques such as tape-carrier-package (TCP), chip-on-film (COF), and gate-in-panel (GIP) methods.
The support film 110 may come in contact with the flexible substrate 120 and support the flexible substrate 120. The support film 110 may also be referred to as a back film, a rear film, a second flexible substrate, or a protective film. In embodiments where the flexible substrate 120 is formed of a flexible plastic thin film, but flexible substrate 120 is vulnerable to external moisture and air. As a result, the display unit 130 formed on the flexible substrate 120 may become damaged. Therefore, in the flexible display device 100 according to one embodiment of the present invention, the support film 110 may be disposed at a rear surface of the flexible substrate 120 to reduce penetration of moisture and air to the display unit 130. The support film 110 may be formed of substantially the same material as the flexible substrate 120, but may be thicker than the flexible substrate 120.
The support film 110 includes a non-bending area and a bending area formed with a bending pattern 111 to reduce rigidity of the support film 110 in the corresponding areas. That is, the bending area of the support film 110 formed with the bending pattern 111 is more flexible than other non-bending areas of the support film 110, and hence, the bending can be localized to bending area formed with the bending pattern 111. Because the support film 110 can be bent along the bending area formed with the bending pattern 111, the flexible substrate 120 and the support substrate 110 can remain fixed even after the bending of the flexible display device 100.
In the example of
The bending area formed with the bending pattern 111 may be centered at the boundary between the display area A and the peripheral circuit area B of the flexible substrate 120. In some embodiments, center of the bending area may be slightly offset towards the peripheral circuit area B so that the bending of the flexible substrate 120 and the support film 110 does not affect the display unit 130. The bending pattern 111 may also be in the form of a plurality of rows, at or near the boundary between the display area A and the peripheral circuit area B of the flexible substrate 120.
Referring to
The bending pattern 111C may be formed in a bending area using various stitching processes in which holes such as a via hole may be formed in the support film 110C. As the various stitching processes for forming the bending pattern 111C, laser processes and mechanical processes such as a piercing process, a punching process and a press process may be used.
Referring to
The flexibility of the support film 110D is increased as the support film 110D is partially carved out along the boundary between the display area A and the peripheral circuit area B. Also, the support film 110D remaining in the bending area (after forming the bending pattern 111D) functions as a hinge for bending the flexible display device 100D. Accordingly, when the half-cut channel has its opening on the bottom surface of the support film 110D, the support film 110D and the flexible substrate 120D can be bent or curved more easily towards the bottom surface of the support film 110D having the hollow channel formed therein.
As shown in
The bending patterns 111D, 111E and 111F may be formed in the bending area using a variety of methods capable of cutting out, or otherwise carving out, the support substrate. For instance, the support substrate can be carved out in a desired shape and size (e.g., depth, width, length) by using laser and/or mechanical tools. Such tools can be employed to conduct various processes, including but not limited to, a piercing process, a punching process and a press process to half-cut the support film according to the desired specification.
In the embodiments described herein, the bending patterns are illustrated as being formed in a bending area of the support film along the boundary between the display area A and the peripheral circuit area B. However, it should be noted that the bending pattern can be formed at a boundary between two adjacent but distinct display areas of the flexible display device. For example, a flexible display device may include two immediately adjacent display areas disposed next to a peripheral circuit area, and the bending patterns can be formed along the boundary between the two immediately adjacent display areas as well as the boundary between the juxtaposed adjacent display areas and the peripheral circuit area.
Further, each of the bending pattern types 111C, 111D, 111E and 111F are described herein as being formed in a discrete flexible display device. Some embodiments of the flexible display device may employ multiple types of the bending patterns described herein. For instance, a flexible display device may include a plurality of bending patterns formed on the support substrate, and one bending patterns can be formed with a plurality of holes and while another bending patterns is formed as a half-cut channel and/or recessed region described above. In some embodiments, one layer of the flexible display device (e.g., flexible display substrate 120) might be configured with one type of bending pattern, while another layer of the flexible display device (e.g., polarizer) is configured with different type(s) of bending pattern.
The bending pattern 111H for facilitating the bending of the support film 110H is formed in the bending area where the pattern 151H are also formed to facilitate the bending of the polarizer 150H. That is, both the pattern 151H and the bending pattern 111H may be formed in the bending area along the boundary between the display area A and the peripheral circuit area B of the flexible substrate 120H. The pattern 151H and the bending pattern 111H may be formed in the same or different shapes. The pattern 151H and the bending pattern 111H may facilitate the bending of the polarizer 150H, the flexible substrate 120H and the support film 110H, particularly, facilitate the bending of the polarizer 150H, the flexible substrate 120H and the support film 110H with respect to the boundary between the display area A and the peripheral circuit area B.
As briefly mentioned above, the flexible display device 100H may include two display areas that are immediately adjacent to each other, and the bending patterns 111H and 151H can be formed at or near the boundary between the two immediately adjacent display areas. Moreover, the bending pattern 111H formed on the support film 110H may differ from the bending pattern 151H formed on the polarizer 150H.
The cover 140I may have a first surface in contact with the flexible substrate 120I including the display unit 130I and corresponding to a top surface of a first area of the flexible substrate 120I, and a second surface extending from the first surface. The first surface of the cover 140I may extend along a plane parallel to the top surface of the display area A of the flexible substrate 120I, and the second surface of the cover 140I may extend along a plane that is not parallel to the top surface of the display area A of the flexible substrate 120I but parallel to the surface of the flexible substrate 120I in the peripheral circuit area B. The first and second surfaces of the cover 140I may adjoin at various angles such as an acute angle, a right angle and an obtuse angle. Preferably, the first and second surfaces of the cover 140I adjoin at an angle in the range of 70 degrees to 110 degrees.
When the first and second surfaces of the cover 140I adjoin at an acute angle, a right angle or an obtuse angle, at least one section of the cover 140I may have a curved shape. For example, when the first and second surfaces of the cover 140I form a right angle as shown in
The flexible substrate 120I may be bent according to the shape of the cover 140I. The flexible substrate 120I, the display unit 130I and the support film 110I may be coupled with the cover 140I as shown in
The cover 140I and the flexible substrate 120I including the display unit 130I may be attached to each other by means of a pressure-sensitive adhesive member. When the pressure-sensitive adhesive member such as a photocurable material or an optically clear adhesive (OCA) is disposed on the cover 140I or the flexible substrate 120I including the display unit 130I, and the cover 140I is coupled with the flexible substrate 120I, the display unit 130I and the support film 110I, the cover 140I may be coupled with the flexible substrate 120I, the display unit 130I and the support film 110I by means of the pressure-sensitive adhesive member.
The cover 140I may include a touch screen panel. The cover 140I may be formed on the first area of the flexible substrate 120I on which the display unit 130I is disposed. Therefore, an image generated on the display unit 130I may be viewed through the cover 140I, and the cover 140I may include a touch screen panel to accommodate an input by touch of a user.
The flexible substrate 220A is a substrate configured to support various elements such as a flexible display device 200A. The flexible substrate 220A may also be referred to as a flexible substrate, a first flexible substrate, or a flexible member. When the flexible substrate 220A is formed of a plastic, the flexible substrate 220A may also be referred to as a plastic film, or a plastic substrate. The flexible substrate 220A may be formed of a flexible material, for example, may be in the form of a film made of materials such as a polyester-based polymer, a silicone-based polymer, an acrylic polymer, a polyolefin-based polymer, and a copolymer thereof. The flexible substrate 220A includes a display area A and a peripheral circuit area B. The display area A of the flexible substrate 220A refers to a display area, that is, an area on which an image is actually displayed. The peripheral circuit area B of the flexible substrate 220A refers to a non-display area, that is, an area on which no image displayed. The flexible substrate 220A is substantially identical to the flexible substrate 120C shown in
The support film 210A is in contact with the flexible substrate 220A. One surface of the flexible substrate 220A on which the display unit 230A is disposed is referred to as a top surface or a front surface of the flexible substrate 220A while the other surface of the flexible substrate 220A coming in contact with the support film 210A may be referred to as a bottom surface or a rear surface of the flexible substrate 220A. The support film 210A may be referred to as a back film, a rear film, a second flexible substrate, or a protective film.
The support film 210A serves to support the flexible substrate 220A. The flexible substrate 220A may be in the form of a flexible plastic thin film. Since this plastic film is vulnerable to external moisture and air, a display unit 230A formed on the flexible substrate 220A may be damaged if exposed to the external moisture and air. Therefore, in the flexible display device 200A according to one embodiment, the support film 210A may be disposed at a rear surface of the flexible substrate 220A to reduce the damage of the elements such as a display unit 230A due to the penetration of external moisture and air. The support film 210A may be formed of substantially the same material as the flexible substrate 220A, but may be thicker than the flexible substrate 220A.
The support film 210A includes a bending area formed with a pattern 211A where the bending of the flexible substrate is localized. Bending of various elements included in the flexible display device 200A may be localized at or near the pattern 211A without affecting the display area A. The pattern 211A may also be referred to as an easily crookable shape, an easily bendable shape, a bendable print, or a bending line. The pattern 211A is substantially identical to the patterns 111C, 111D, 111E and 111F shown with reference to
Referring to
The support film 210A may have various sectional shapes. When an external force is applied to the support film 210A, the support film 210A may have a “-” letter-shaped section. On the other hand, when an external force is applied to the support film 210A, the support film 210A is bent at the boundary defined as the pattern 211A, and thus may have a curved shape or a curved state. For example, the support film 210A may have a “┐”-shaped section. Also, when an external force is applied to the support film 210A, the support film 210A may have a non-linear section. Here, the term “non-linear section” encompasses a case in which shapes other than a straight line are present in a section of the support film 210A, and may refer to a circular or curved section having a certain radius of curvature.
In some embodiments, the support film 210A may be bent at the boundary defined as the pattern 211A, and the flexible substrate 220A having the display unit 230A disposed thereon may then be attached to the bent support film 210A. That is, the support film 210A may be bent at the boundary defined as the pattern 211A into various shapes, and the flexible substrate 220A may then be attached to the bent support film 210A. Therefore, a tension of the bent flexible substrate 220A may be decreased. In some embodiments, to fix the bent support film 210A as necessary, a double-sided adhesive tape may be used. In this case, the flexible substrate 220A may be attached to the support film 210A in a bent state by means of the double-sided adhesive tape.
Referring to
The support film 210B includes a bending pattern 211B for facilitating bending thereof. The bending pattern 211B may include via holes, a groove or a combination thereof. The bending pattern 211B may be formed in an area of the support film 210B corresponding to the boundary between the display area A and the peripheral circuit area B of the flexible substrate 220B. The bending pattern 211B may be formed in an area of the support film 210B at or near the boundary between the display area A and the peripheral circuit area B of the flexible substrate 220B so as to facilitate bending of the support film 210B and the flexible substrate 220B disposed on the support film 210B. More particularly, the bending pattern 211B may serve to facilitate the bending of the support film 210B and the flexible substrate 220B with respect to the boundary between the display area A and the peripheral circuit area B. As described above, since the peripheral circuit areas B of the flexible substrate 220B are located at both sides of the display area A of the flexible substrate 220B, the patterns 211B may be formed in areas corresponding to the two boundaries between the display area A and the peripheral circuit areas B of the flexible substrate 220B. The support film 210B is substantially identical to the support film 210A shown in
Referring to
Referring to
Referring to
As previously described, however, each bending pattern 211D can be different bending pattern type (e.g., a plurality of holes, half-cut channel, recessed region). It should be appreciated that each of the plurality of via holes can have different shape and size depending on the desired flexibility of the support film 210D. For example, some part of the flexible display device may be need additional flexibility than some other parts of the flexible display device. As such, the bending pattern disposed at the part requiring more flexibility may be formed with more number of via holes or via holes having a larger size. When other types of the bending patterns are used, the part of the display device requiring more flexibility may employ a half-cut channel penetrating deeper (i.e., half-cut channel having larger depth) than the half-cut channel used in other parts of the display device. Likewise, larger area of the support film can be carved out at the part of the display device requiring more flexibility.
The bending pattern 211D may be formed in an area of the support film 210D corresponding to the boundary between a first area (e.g., display area or peripheral circuit area) and a second area (e.g., display area or peripheral circuit area) of a flexible substrate 220D. The bending pattern 211D may be formed in the area of the support film 210D corresponding to the boundary between the first area and the second area of the flexible substrate 220D so as to facilitate bending of the flexible substrate 220D disposed on the support film 210D and the support film 210D. More particularly, the pattern 211D may serve to facilitate bending of the support film 210D and the flexible substrate 220D with respect to the boundary between the first area and the second area. As described above, since the second areas of the flexible substrate 220D are positioned on both sides of the first area of the flexible substrate 220D, the patterns 211D may be formed in areas corresponding to the two boundaries between the first area and the second area of the flexible substrate 220D. The support film 210B is substantially identical to the support film 210B shown in
Referring to
Referring to
First, referring to
The protective layer 390A coming in contact with the flexible substrate 320A and covering a display area A and a peripheral circuit area B of the flexible substrate 320A is disposed. The protective layer 390A includes a sealant 395A and a protective film 396A. The protective layer 390A may be configured to be wider according to a method of sealing internal elements of the flexible display device 300A. For example, a method of sealing the flexible display device 300A includes thin film encapsulation (TFE), face sealing, etc. As described herein, a protective layer formed using a face sealing method favorable for flexible display applications among various sealing methods is used as the protective layer 390A, but the present invention is not limited thereto. The protective layer 390A may also be formed using other encapsulation methods. The protective film 396A is glued onto the sealant 395A in the form of a thin film, and the protective film 396A serves to protect the internal elements of the flexible display device 300A. The protective film 396A may be formed of a flexible material, for example, a plastic, a metal, a metal oxide, a ceramic oxide and a polymer material, or a combination of a plastic, a metal, a metal oxide, a ceramic oxide and/or a polymer material.
The sealant 395A in the protective layer 390A is formed at the display area A of the flexible substrate 320A, and the protective films 396A are formed at the display area A and the peripheral circuit area B of the flexible substrate 320A. The sealant 395A serves to seal the internal elements of the flexible display device 300A, especially the display unit 330A. The sealant 395A is formed at the display area A of the flexible substrate 320A on which the display unit 330A is disposed. The sealant 395A may be formed at the display area A of the flexible substrate 320A. In some embodiments, however, the sealant 395A may also be formed at both the display area A and the peripheral circuit area B of the flexible substrate 320A.
Next, referring to
A pattern 391B is formed in an area of a protective film 396B of the protective layer 390B corresponding to the boundary between a display area A and a peripheral circuit area B of the flexible substrate 320B. The pattern 391B may be formed in the area of the protective film 396B of the protective layer 390B corresponding to the boundary between the display area A and the peripheral circuit area B of the flexible substrate 320B to facilitate bending of a polarizer 390B, the flexible substrate 320B and the support film 310B, particularly, to localize bending of the protective layer 390B, the flexible substrate 320B and the support film 310B with respect to the boundary between the display area A and the peripheral circuit area B.
Subsequently, referring to
The polarizer 350C in contact with the flexible substrate 320C and covering a display area A of the flexible substrate 320C is disposed. The polarizer 350C may also be referred to as a polarizer film. In case where the display unit 330C is an organic light emitting diode, a contrast ratio (CR) is markedly degraded when an external light incident from the outside is reflected on a metal electrode or a wire of the organic light emitting diode. In the flexible display device 300C according to another embodiment of the present invention, degradation of the contrast ratio caused by reflection of external light may be reduced or eliminated by disposing the polarizer 350C on the display area A of the flexible substrate 320C, that is, the display unit 330C. Also, the polarizer 350C may be formed only on the display area A of the flexible substrate 320C to reduce or prevent peeling of the polarizer 350C when a peripheral circuit area B of the flexible substrate 320C is bent.
A flexible substrate 420A supports various elements of a flexible display device 400A. The flexible substrate 420A may also be referred to as a flexible substrate, a first flexible substrate, or a flexible member. When the flexible substrate 420A is formed of a plastic, the flexible substrate 420A may be referred to as a plastic film, or a plastic substrate.
The flexible substrate 420A may be formed of a flexible material such as a polyester-based polymer, a silicone-based polymer, an acrylic polymer, a polyolefin-based polymer, and a copolymer thereof. More particularly, the flexible substrate 420A may be formed of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polysilane, polysiloxane, polysilazane, polycarbosilane, polyacrylate, polymethacrylate, polymethylacrylate, polyethylacrylate, polyethylmetacrylate, a cyclic olefin copolymer (COC), a cyclic olefin polymer (COP), polyethylene (PE), polypropylene (PP), polyimide (PI), polymethylmetacrylate (PMMA), polystyrene (PS), polyacetal (POM), polyether ether ketone (PEEK), polyestersulfone (PES), polytetrafluoroethylene (PTFE), polyvinylchloride (PVC), polycarbonate (PC), polyvinylidenefluoride (PVDF), a perfluoroalkyl polymer (PFA), a styrene acrylonitrile copolymer (SAN), and a combination thereof. When the flexible display device 400A is to be transparent, the flexible substrate 420A may be formed of a transparent flexible material.
The flexible substrate 420A includes a display area A, a peripheral circuit area B and a third area C. The display area A of the flexible substrate 420A refers to a display area, that is, an area on which an image is actually displayed. The peripheral circuit area B and the third area C of the flexible substrate 420A refer to non-display areas, that is, areas on which no image is displayed.
The peripheral circuit area B of the flexible substrate 420A is a non-display area which is positioned at the outermost area of the flexible substrate 420A. The peripheral circuit area B of the flexible substrate 420A is positioned at an edge portion of the flexible substrate 420A, and thus may also be referred to as an edge area or a bezel area.
The third area C of the flexible substrate 420A is a non-display area which is positioned between the display area A and the peripheral circuit area B of the flexible substrate 420A. The third area C of the flexible substrate 420A is positioned at a peripheral portion of the first area of the flexible substrate 420A, and positioned between the display area A and the peripheral circuit area B of the flexible substrate 420A, and thus may also be referred to as a peripheral area, a middle area, or a bezel area.
A display unit 430A is disposed at all or part of the display area A of the flexible substrate 420A. The display unit 430A is an element for actually generating an image, and thus may be referred to as an image display unit 430A, or a display panel. The display unit 430A may be used without limitation as long as it can be configured to display an image. It is described herein that the display unit 430A is an organic light emitting diode for displaying an image through an organic light emitting layer, and define that the image is displayed on an entire area corresponding to the display unit 430A. A polarizer 450A capable of improving a contrast ratio is disposed on the display unit 430A.
The support film 410A serves to support the flexible substrate 420A. As described above, the flexible substrate 420A is in the form of a flexible plastic thin film. However, since this plastic film is vulnerable to penetration of moisture and air from the outside, there is a possibility of elements, such as a display unit 430A, formed on the flexible substrate 420A becoming damaged. Therefore, in the flexible display device 400A according to still another embodiment of the present invention, the support film 410A may be disposed at a rear surface of the flexible substrate 420A to minimize damage of the elements such as a display unit 430A caused by the penetration of moisture and air from the outside. The support film 410A may be formed of substantially the same material as the flexible substrate 420A, but have a relatively larger thickness than the flexible substrate 420A.
The support film 410A may be formed with a shape and size corresponding to those of the flexible substrate 420A. Since the support film 410A functions to support the flexible substrate 420A, the shape and size of the support film 410A may correspond to those of the flexible substrate 420A, but the present invention is not limited thereto. For example, the shape and size of the flexible substrate 420A and the shape and size of the support film 410A may be determined in an independent manner.
The support film 410A includes a pattern 411A for facilitating bending thereof. The pattern 411A for facilitating the bending may be referred to as a pattern 411A for facilitating bending of the support film 410A. As a result, bending of various elements included in the flexible display device 400A may also be facilitated by facilitating the bending of the support film 410A. The pattern 411A for facilitating the bending may also be referred to as an easily crookable shape, an easily bendable shape, a bendable print, or a bending line.
The pattern 411A may include at least one of a via hole and a groove of the support film 410A. The via hole and groove may be formed in various shapes such as a cylindrical shape, a polyprismatic shape, a conical shape, and a polypyramid shape, and the sizes of the via hole and groove may be determined according to various designs.
The pattern 411A may be formed using various processes capable of forming a via hole or a groove in the support film 410A. As various processes for forming the pattern 411A, laser processes and mechanical processes such as a piercing process, a punching process, and a press process may be used.
The pattern 411A may be formed in an area of the support film 410A corresponding to the third area C between the display area A and the peripheral circuit area B of the flexible substrate 420A. The pattern 411A may be formed in the area of the support film 410A corresponding to the third area C of the flexible substrate 420A so as to facilitate bending of the support film 410A and the flexible substrate 420A disposed on the support film 410A, particularly, to facilitate bending of the support film 410A and the flexible substrate 420A with respect to the third area C. For the sake of convenience of description,
An area of the support film 410A corresponding to the display area A or the peripheral circuit area B of the flexible substrate 420A may have a higher average volume than an area of the support film 410A corresponding to the third area C of the flexible substrate 420A. As described above, the pattern 411A is formed in the area of the support film 410A corresponding to the third area C of the flexible substrate 420A. Therefore, since a via hole or a groove is formed in the third area C of the flexible substrate 420A, the area of the support film 410A corresponding to the display area A or the peripheral circuit area B of the flexible substrate 420A may have a higher average than the area of the support film 410A corresponding to the third area C of the flexible substrate 420A. In some embodiments, the area of the support film 410A corresponding to the display area A or the peripheral circuit area B of the flexible substrate 420A may have a greater thickness than the area of the support film 410A corresponding to the third area C of the flexible substrate 420A.
As described above, the display area A of the flexible substrate 420A is a display area on which an image is actually displayed, but the peripheral circuit area B of the flexible substrate 420A is a non-display area. Even if the peripheral circuit area B of the flexible substrate 420A is positioned on the same plane as the display area A of the flexible substrate 420A, no image is visible on the peripheral circuit area B of the flexible substrate 420A. Therefore, a configuration of covering the peripheral circuit area B of the flexible substrate 420A should be present as a separate protective member that may be positioned on the flexible substrate 420A, which results in restriction on design of the flexible display device and can be aesthetically unpleasing to consumers. Accordingly, it is advantageous to decrease the bezel area by bending the peripheral circuit area B of the flexible substrate 420A toward a rear or lateral surface of the flexible substrate 420A. However, the support film 410A has a larger thickness than the flexible substrate 420A. Therefore, when the support film 410A is bent, an elastic restoring force may be generated, making it difficult to maintain a bent shape of the support film 410A. Alternatively or in addition, a configuration of the display unit 430A or the polarizer that may be disposed on the flexible substrate 420A may be peeled off in a bent state. In the flexible display device 400A according to one embodiment of the present invention, the pattern 411A for facilitating the bending may be formed in an area of the support film 410A corresponding to the third area C of the flexible substrate 420A to minimize an elastic restoring force of the support film 410A. As a result, it is possible to facilitate the bending of the flexible substrate 420A, improve peeling of the elements formed on the flexible substrate 420A, and provide a more improved design.
The drive circuit unit 470B configured to transfer various signals to the display unit 430B from the outside, and the wire 465B configured to provide electrical connection between the display unit 430B and the drive circuit unit 470B are formed. The wire 465B is electrically connected with a wire 471B of the drive circuit unit 470B. When flexible substrate 420B having the display unit 430B, the wire 465B and a pad portion 472B formed therein is bent, strain is caused in the display unit 430B and the wire 465B formed on the flexible substrate 420B. In the flexible display device 400B of
The organic film 480B is formed at a space between the display unit 430B and the drive circuit unit 470B. As described above, a pattern 411B is formed in an area corresponding to the third area C of the flexible substrate 420B, and the flexible display device 400B is bent with respect to the third area C of the flexible substrate 420B. As a result, an area in which the highest strain is formed at the third area C of the flexible substrate 420B. Therefore, it is preferred that the organic film 480B is formed to cover the third area C of the flexible substrate 420B. In some embodiments, when the space between the display unit 430B and the drive circuit unit 470B corresponds to a part of a second area and the third area C of the flexible substrate 420B as shown in
Since the flexible substrate 420B is flexible, the display area of the flexible display device 400B may also be bent in addition to the third area C. In such cases, the organic film 480B may be disposed on the display area A as well as the third area C of the flexible substrate 420B so as to configure the areas to be the neutral plane within the flexible display device 400B is bent as a whole.
A flexible substrate 420C includes a display area A, a peripheral circuit area B, a third area C, a fourth area D and a fifth area E. The display area A of the flexible substrate 420A refers to a display area, that is, an area on which an image is actually displayed. The peripheral circuit area B, the third area C, the fourth area D and the fifth area E of the flexible substrate 420C refer to non-display areas, that is, areas on which no image is displayed. The display area A, the peripheral circuit area B and the third area C of the flexible substrate 420C are substantially identical to the display area A, the peripheral circuit area B and the third area C of the flexible substrate 420A shown in
The fifth area E of the flexible substrate 420C is a non-display area which is positioned at the outermost area of the flexible substrate 420C. Since the fifth area E of the flexible substrate 420C is positioned at an edge portion of the flexible substrate 420C, the second area E of the flexible substrate 420C may also be referred to as an edge area or a bezel area.
The fourth area D of the flexible substrate 420C is a non-display area which is positioned between the third area C and the fifth area E of the flexible substrate 420C. Also, since the fourth area D of the flexible substrate 420C is positioned at a peripheral portion of the display area A of the flexible substrate 420C, and positioned between the display area A and the fifth area E of the flexible substrate 420C, the fourth area D of the flexible substrate 420C may be referred to as a peripheral area, a middle area or a bezel area.
A support film 410C is disposed to come in contact with the flexible substrate 420C. One surface of the flexible substrate 420C on which a display unit 430C is disposed is a top or front surface of the flexible substrate 420C while the other surface of the flexible substrate 420C with which the support film 410C comes in contact may be referred to as a bottom or rear surface of the flexible substrate 420C.
The support film 410C includes a bending pattern 411C for facilitating bending of the support film 410C. As a result, bending of various elements included in the flexible display device 400C may also be facilitated by facilitating the bending of the support film 410C. The pattern 411C for facilitating the bending may also be referred to as an easily crookable shape, an easily bendable shape, a bendable print, or a bending line.
The pattern 411C for facilitating the bending includes a pattern 411C1 for facilitating primary bending and a pattern 411C2 for facilitating secondary bending. The bending pattern 411C1 for facilitating the primary bending and the bending pattern 411C2 for facilitating the secondary bending may be formed in areas of the support film 410C corresponding to the third area C and the fourth area D of the flexible substrate 420C, respectively. The bending pattern 411C1 for facilitating the primary bending and the bending pattern 411C2 for facilitating the secondary bending may be formed with the same shape and size, or formed with different shapes and sizes.
A display unit 430D may include a first display unit 431D and a second display unit 432D. The first display unit 431D may be formed at a first area A of a flexible substrate 420D, and the second display unit 432D may be formed at a second area B of the flexible substrate 420D. As the display unit 430D is divided into the first display unit 431D and the second display unit 432D. In some embodiments, the first display unit 431D and the second display unit 432D are configured to operate independently from one another. That is, the first display unit 431D and the second display unit 432D may be configured to receive control signal from a different source (e.g., distinct GIP, distinct content source, distinct drive IC, etc). As such, one display unit may be turned off while the other display unit is displaying image. Also, one display unit may play content from a first input device while the other display unit plays content from a second input device.
When a support film 410D and the flexible substrate 420D are bent with respect to a third area C of the flexible substrate 420D, the second display unit 432D may display an image on a lateral or rear surface of a flexible display device 400D. In some embodiments, the display unit 430D may further include a third display unit. Here, the third display unit may be formed at a fifth area E of the flexible substrate 420D to independently display an image.
A polarizer 450D is formed on the first area A, the second area B and the third area C of the flexible substrate 420D. In the case where the display unit 430D is an organic light emitting diode, a contrast ratio is markedly degraded when an external light incident from the outside is reflected on a metal electrode or a wire of the organic light emitting diode. In the flexible display device 400D according to still another embodiment of the present invention, since the display unit 430D is formed on the first area A and the second area B of the flexible substrate 420D, degradation of the contrast ratio caused by reflection of external light may be prevented by disposing the polarizer 450D on the first area A, the second area B, and the third area C between the second area B and the first area A of the flexible substrate 420D. Also, since the polarizer 450D is formed on the first area A, the second area B and the third area C of the flexible substrate 420D, the polarizer 450D may be curved with respect to the third area C of the flexible substrate 420D as the flexible display device 400D is bent.
The support film 510 includes a first support film 515 and a second support film 516. The first support film 515 is disposed on a rear surface of the first area A, and the second support film(s) 516 is disposed the rear surface of the second area(s) B of the flexible substrate 520. The first support film 515 and the second support film(s) 516 are spaced apart from each other with a gap formed between the first support film 515 and the second support film(s) 516. Since there is the gap formed between the first support film 515 and the second support film 516 the elastic restoring force of the support film 510, as a whole, is reduced. Accordingly, bending of the flexible substrate 520 can be localized around the gap and thereby prevent or reduce the peeling of the elements formed on the flexible substrate 520.
In some embodiments, the gap between the first support film 515 and the second support film 516 may be filled with a resin material (e.g., sealant, thermosetting resin) to protect the components on the flexible substrate 520 from the external environments such as moisture or oxygen. The resin material, when filled and cured in the gap, should be less rigidity than the support films adhered on other parts of the display device.
In some embodiments, a side end of first support film 515 and a side end of the second support film 516 are not perpendicular to the corresponding portion of the flexible display substrate, but are angled so that the gap between the two adjacent support films 515 and 516 is reduced upon bending of the flexible substrate 520. This way, the resin material for filling the gap can be wholly eliminated or at least reduced in the flexible display device.
First, a display unit is formed on a flexible substrate (S60). Forming the display unit on the flexible substrate will be described in further detail with reference to
Referring to
Referring to
Referring to
Subsequently, a cover is disposed on the polarizer (S63). Disposing the cover is substantially identical to the process of disposing the cover shown in
A pattern for facilitating bending is formed in at least one of the support film 710, the polarizer 750 and a cover 740. For the sake of convenience of description,
According to the embodiments of the present invention, the flexible display device and the method of manufacturing the same have at least the following effects. The flexible display device capable of realizing a narrow bezel-type or bezel-free display device and also enables improved types of design and improved method of manufacturing the flexible display device. Also, narrow bezel-type or bezel-free display device can be embodied by facilitating bending of a bezel area of the flexible display device. Further, damage to the bending area can be reduced.
It will be apparent to those skilled in the art that various modifications can be made to the above-described embodiments of the present invention without departing from the scope of the invention. Thus, it is intended that the present invention covers all such modifications provided they come within the scope of the appended claims and their equivalents.
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