Display device

Abstract

A display device comprising: a display panel comprising a folding region configured to be foldable about a folding axis and a non-folding region adjacent to the folding region; and a window on the display panel and configured to be foldable with the display panel, wherein: a side surface of the display panel has a first surface roughness in the folding region and a second surface roughness in the non-folding region; the first surface roughness is lower than the second surface roughness; and a side surface of the window has a same surface roughness in the non-folding region and the folding region.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2021-0037484, filed with the Korean Intellectual Property Office on March 23, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Some aspects of embodiments of this disclosure relate to display devices and methods of manufacturing display devices. Background Technology

[0004] Electronic devices such as smartphones, tablets, laptops, and smart TVs are being developed. These devices typically have displays to graphically present information. In addition to displays, they usually include various electronic modules.

[0005] Display devices can have flexible display components that can be folded or rolled up. Unlike flat panel displays, flexible displays can be folded, rolled up, or bent (e.g., similar to paper). Flexible displays, which can change shape in various ways, are easier for users to carry and can improve user convenience.

[0006] The information disclosed in this background section is only intended to enhance the understanding of the background art, and therefore the information discussed in this background section does not necessarily constitute prior art. Summary of the Invention

[0007] Some aspects of embodiments of this disclosure relate to display devices and methods of manufacturing display devices, and for example, to display devices that can be folded about a folding axis and methods of manufacturing said display devices.

[0008] Some aspects of embodiments of this disclosure include a display device with relatively improved folding reliability and a method of manufacturing the display device.

[0009] Some embodiments of the present invention include a display device comprising: a display panel including a folding region configured to be foldable about a folding axis and a non-folding region adjacent to the folding region; and a window on the display panel and configured to be foldable together with the display panel. A side surface of the display panel has a first surface roughness in the folding region and a second surface roughness in the non-folding region. The first surface roughness is lower than the second surface roughness. The side surface of the window has the same surface roughness in both the non-folding region and the folding region.

[0010] According to some embodiments, the window may include thin-film glass.

[0011] According to some embodiments, the display device may further include an anti-reflective layer on the display panel and foldable together with the display panel.

[0012] According to some embodiments, the side surface of the antireflective layer has a third surface roughness in the folded region and a fourth surface roughness in the unfolded region. The third surface roughness may be lower than the fourth surface roughness.

[0013] According to some embodiments, the display panel includes a recessed portion in the folded region. When the direction of the folding axis is referred to as a reference direction, the display panel has a first width in the non-folded region and a second width in the folded region in the reference direction. The second width may be smaller than the first width.

[0014] According to some embodiments, the recessed portion may include a curved shape.

[0015] According to some embodiments, in the reference direction, the window has the same width in the folded area and in the non-folded area.

[0016] According to some embodiments, the window includes a transmissive region and a frame region adjacent to the transmissive region, through which light passes; and the recessed portion is spaced apart from the transmissive region.

[0017] According to some embodiments of the present invention, a display device includes: a display panel including a folding region configured to be foldable about a folding axis and a non-folding region adjacent to the folding region; and a window on the display panel and configured to be foldable together with the display panel. A plurality of side surfaces of the display panel include a first side surface having a first surface roughness and a second side surface having a second surface roughness higher than the first surface roughness. The side surfaces of the window have the same surface roughness in both the non-folding region and the folding region. The first side surface includes at least one of the plurality of side surfaces of the display panel that overlaps with the folding region.

[0018] According to some embodiments, the window may include thin-film glass.

[0019] According to some embodiments, the first side surface may have a curved shape.

[0020] According to some embodiments, the first side surface may include one of the plurality of side surfaces of the display panel that overlaps with the folded region.

[0021] According to some embodiments, the first side surface may further include one of the plurality of side surfaces of the display panel that overlaps with a portion of the non-folded region.

[0022] According to some embodiments of the present invention, the display device may further include an anti-reflective layer on the display panel and foldable together with the display panel. The side surface of the anti-reflective layer includes a third side surface having a third surface roughness and a fourth side surface having a fourth surface roughness higher than the third surface roughness. The third side surface overlaps with the first side surface.

[0023] According to some embodiments of the present invention, a method of manufacturing a display device includes: manufacturing a display module comprising a foldable region foldable about a folding axis and a non-foldable region adjacent to the foldable region; and arranging a window foldable together with the display module on the display module. The manufacturing of the display module includes obtaining a preliminary display module comprising an effective region and a non-effective region from a parent substrate by performing a first cutting process along a first cutting line. The manufacturing of the display module further includes removing the non-effective region from the effective region by performing a second cutting process along a second cutting line located at the boundary between the non-effective region and the effective region. The non-effective region includes at least a region extending from the foldable region.

[0024] According to some embodiments, the window may include thin-film glass.

[0025] According to some embodiments, the first cutting process may use a first laser having a first wavelength, and the second cutting process may use a second laser having a second wavelength different from the first wavelength.

[0026] According to some embodiments, the first cutting process includes irradiating the first laser repeatedly n times, and the second cutting process includes irradiating the second laser repeatedly m times. n can be a natural number greater than 1, and m can be a natural number greater than n.

[0027] According to some embodiments, the first laser is irradiated at a first frequency in the first cutting process, and the second laser is irradiated at a second frequency in the second cutting process, wherein the second frequency may be greater than the first frequency.

[0028] According to some embodiments, the manufacturing of the display module may further include arranging an anti-reflective layer on the preliminary display module.

[0029] According to some embodiments, the display panel includes a recessed portion formed by the second cutting process, and the window includes a transmissive region and a frame region adjacent to the transmissive region, through which light passes. The recessed portion is spaced apart from the transmissive region.

[0030] According to some embodiments, the recessed portion may include a curved shape. Attached Figure Description

[0031] The accompanying drawings are included to provide a further understanding of the inventive concept and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the inventive concept and, together with this description, serve to explain the principles of the inventive concept. In the drawings:

[0032] Figure 1 These are perspective views of display devices according to some embodiments of the present invention;

[0033] Figure 2A It shows Figure 1 The display device shown is folded along the first folding axis.

[0034] Figure 2B It shows Figure 1 The display device shown is folded outward along the first folding axis;

[0035] Figure 3A It shows Figure 1 The display device shown is folded inward along the second folding axis;

[0036] Figure 3B It shows Figure 1 The display device shown is in a state where it is folded outward along the second folding axis;

[0037] Figure 4A and Figure 4B This is an exploded perspective view of a display device according to some embodiments of the present invention;

[0038] Figure 5A It is along Figure 4B The cross-sectional view of the folded region intercepted by line I-I' is shown in the figure;

[0039] Figure 5B It is along Figure 4B The cross-sectional view of the non-folded region intercepted by line II-II' is shown in the figure;

[0040] Figure 6 It is a photograph of the side surface of the display module positioned in the folded and non-folded areas;

[0041] Figures 7A to 7C This is a process diagram illustrating the first cutting process according to some embodiments of the concept of the present invention;

[0042] Figures 8A to 8C This is a process diagram illustrating a second cutting process according to some embodiments of the concept of the present invention; and

[0043] Figures 9A to 12B This is a plan view illustrating a second cutting process according to some embodiments of the concept of the present invention. Detailed Implementation

[0044] In this specification, it will be understood that when an element (or region, layer, portion, etc.) is referred to as being "on", "connected to", or "coupled to" another element, the element may be directly on, directly connected to, or directly coupled to the other element, or there may be intermediary elements.

[0045] The same reference numerals always refer to the same elements. Additionally, in the accompanying drawings, the thickness, scale, and dimensions of elements are exaggerated for the purpose of effectively describing the technical content.

[0046] As used herein, the term “and / or” includes any and all combinations of one or more of the listed items.

[0047] It will be understood that although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be named a second element without departing from the scope of the invention. Similarly, a second element may be named a first element. Unless otherwise stated, singular terms include plural forms.

[0048] For ease of description, terms such as "below," "under," "above," and "above" are used herein to describe the relationship of one element to other elements (multiple elements) as shown in the accompanying drawings. These terms are relative concepts and are described based on the directions indicated in the drawings.

[0049] It will be understood that, when used in this specification, the terms “comprising” and / or “having” indicate the presence of the stated features, integrals, steps, operations, elements, components and / or groups thereof, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or groups thereof.

[0050] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It will also be understood that, unless expressly defined herein, terms (such as those defined in general dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant field and should not be interpreted as having an idealized or overly formal meaning.

[0051] In the following description, some aspects of embodiments of the inventive concept will be described in more detail with reference to the accompanying drawings.

[0052] Figure 1 This is a perspective view of a display device according to some embodiments of the present invention.

[0053] Reference Figure 1 The display device DD has a rectangular shape, which has a short side in a first direction DR1 and a long side in a second direction DR2 intersecting the first direction DR1. However, the shape of the display device DD is not limited to this, and the display device DD can have any suitable shape (e.g., circular, elliptical, square, rectangular, irregular shape, etc.) depending on the design of the display device DD.

[0054] The display device DD can be a foldable electronic device. For example, according to some embodiments of the present invention, the display device DD can be folded along folding axes FX1 and FX2 extending in one direction (e.g., a set or predetermined direction). Hereinafter, the folded state along folding axes FX1 and FX2 is defined as the folded state, and the unfolded state is defined as the unfolded state.

[0055] Folding axes FX1 and FX2 can extend along either a first direction DR1 or a second direction DR2. According to some embodiments of the present invention, the folding axis extending along the second direction DR2 is defined as the first folding axis FX1, and the folding axis extending along the first direction DR1 is defined as the second folding axis FX2. The display device DD can include one of the first folding axis FX1 and the second folding axis FX2. That is, the display device DD can be folded along one of the first folding axis FX1 and the second folding axis FX2.

[0056] The display device DD according to some embodiments of the present invention can be not only a large display device such as a television or monitor, but also a small to medium-sized display device such as a mobile phone, tablet computer, car navigation system, or game console. These are presented by way of example only, and the display device DD according to the present invention can be applied to any suitable electronic device without departing from the spirit and scope of the embodiments of the present invention.

[0057] like Figure 1 As shown, the display device DD can display an image IM on a display surface IS parallel to each of the first direction DR1 and the second direction DR2, facing a third direction DR3. The display surface IS on which the image IM is displayed can correspond to the front surface of the display device DD.

[0058] The display surface IS of the display device DD can be divided into multiple regions. The display surface IS of the display device DD can be divided into a transmissive region TA and a border region BZA. The transmissive region TA can be the area where the image IM is displayed. The user visually identifies the image IM through the transmissive region TA. According to some embodiments, the transmissive region TA is shown in a quadrilateral shape with rounded vertices. However, this is shown as an example, and the transmissive region TA can have various shapes and is not limited to any one embodiment.

[0059] The border region BZA is adjacent to the transmissive region TA. The border region BZA may have a color (e.g., a set or predetermined color). The border region BZA may surround the transmissive region TA. Therefore, the shape of the transmissive region TA can be substantially defined by the border region BZA. However, this is shown by way of example, and the border region BZA may be arranged to be adjacent only to one side of the transmissive region TA, or the border region BZA may be omitted. The display device DD according to some embodiments of the present invention may include various embodiments and is not limited to any one embodiment.

[0060] The display device DD according to the present invention can sense user input TC (e.g., touch input) applied externally. User input TC includes various types of external input, such as a part of the user's body, light, heat, or pressure. According to some embodiments, user input TC is shown as a user's hand applied to the front surface of the display device DD. However, this is shown as an example, and as mentioned above, user input TC can be provided in various forms. Furthermore, depending on the structure of the display device DD, the display device DD can sense user input TC applied to the side or rear surface of the display device DD, and embodiments according to the present invention are not limited to any one embodiment.

[0061] The display device DD can display an image IM and simultaneously sense user input TC by activating the display surface IS. According to some embodiments, the area for sensing user input TC is shown as being provided in the transmissive area TA of the displayed image IM. However, this is shown as an example, and the area for sensing user input TC can be provided in the border area BZA or in the entire area of ​​the display surface IS.

[0062] Figure 2A It shows Figure 1The display device shown is folded inward along the first folding axis, and Figure 2B It shows Figure 1 The display device shown is in a state where it is folded outward along the first folding axis.

[0063] Reference Figure 1 and Figure 2A Depending on the type of operation, the display device DD may have multiple regions defined within it. These multiple regions may be divided into at least one of non-folding regions NFA1 and NFA2, and a folding region FA. According to some embodiments of the present invention, the display device DD includes two non-folding regions NFA1 and NFA2, and a folding region FA defined between the two non-folding regions NFA1 and NFA2.

[0064] According to some embodiments of the present invention, the non-foldable regions NFA1 and NFA2 may include a first non-foldable region NFA1 and a second non-foldable region NFA2. The first non-foldable region NFA1 is adjacent to one side of the foldable region FA in a first direction DR1, and the second non-foldable region NFA2 is adjacent to the other side of the foldable region FA in the first direction DR1. The foldable region FA is a region that is foldable along a first folding axis FX1 and substantially forms a curvature. Here, the first folding axis FX1 may extend in a second direction DR2 (i.e., in a direction parallel to the long axis of the display device DD).

[0065] The display device DD can be folded inward or outward. Here, folding inward means folding so that the two parts of the display surface IS face each other, and folding outward means folding so that the two parts of the rear surface of the display device DD face each other.

[0066] Figure 2A The display device DD shown can be folded inward so that the display surface IS of the first non-folded region NFA1 and the display surface IS of the second non-folded region NFA2 face each other.

[0067] Reference Figure 2B The display device DD can be folded outward along the first folding axis FX1. When the display device DD is folded outward, the display surface IS can be exposed to the outside.

[0068] The display device DD can be folded into an inward folded state and an outward folded state, but according to some embodiments of the present invention, the display device DD can be folded only in one of the inward folded state and the outward folded state.

[0069] Figure 3A It shows Figure 1 The display device shown is folded inward along the second folding axis. Figure 3B It shows Figure 1The display device shown is in a state where it is folded outward along the second folding axis.

[0070] According to some embodiments of the present invention, a first non-foldable region NFA1 may be adjacent to one side of the foldable region FA in a second direction DR2, and a second non-foldable region NFA2 may be adjacent to the other side of the foldable region FA in the second direction DR2. The foldable region FA is a region that is foldable along a second folding axis FX2 and substantially forms a curvature. Here, the second folding axis FX2 may extend in a first direction DR1 (i.e., in a direction parallel to the minor axis direction of the display device DD).

[0071] The display device DD can be folded inward or outward along the second folding axis FX2.

[0072] Because the display device DD includes a first folding axis FX1 and a second folding axis FX2, the display device DD can be folded in both the minor axis direction and the major axis direction. However, as an example for illustrating an embodiment of the inventive concept, the display device DD may have only one of the first folding axis FX1 and the second folding axis FX2.

[0073] According to some embodiments, the display device DD has a folded region FA defined within the display device DD; however, embodiments based on the present invention are not limited thereto. According to some embodiments based on the present invention, the display device DD may have multiple folded regions FA defined within the display device DD.

[0074] Figure 4A and Figure 4B This is an exploded perspective view of a display device according to some embodiments of the present invention.

[0075] Reference Figure 4A A display device DD according to some embodiments of the present invention may include a display module DM and a window WM disposed on the display module DM. The display module DM may include a display panel DP and an upper module UM. In the following general description of the display module DM, it can also be understood as a description of each component included in the display module DM. For example, "the display module DM includes a recessed portion HM (see Figure 4B ")" can be understood as "the display panel DP includes the recessed portion HM", and "the width of the display module DM" can be understood as "the width of the display panel DP".

[0076] The display panel DP according to some embodiments of the present invention can be a light-emitting display panel and is not particularly limited thereto. For example, the display panel DP can be an organic light-emitting display panel, an inorganic light-emitting display panel, or a quantum dot light-emitting display panel. The light-emitting element of an organic light-emitting display panel can contain organic light-emitting materials, and the light-emitting element of an inorganic light-emitting display panel can contain inorganic light-emitting materials. The light-emitting element of a quantum dot light-emitting display panel can contain quantum dots and quantum rods, etc. Hereinafter, the display panel DP will be described as an organic light-emitting display panel. The display panel DP can output an image IM (see...). Figure 1 ), and the output image can be displayed on the display surface IS.

[0077] The display panel DP can be a flexible display panel. Therefore, the display panel DP can rotate around the first folding axis FX1 (see...). Figure 1 ) or the second folding axis FX2 (see Figure 1 Folding or unfolding. In other words, corresponding to the folding area FA and non-folding areas NFA1 and NFA2 of the display device DD, the display panel DP may also include a folding area FA configured to be foldable about a folding axis FX1 or FX2 and non-folding areas NFA1 and NFA2 adjacent to the folding area FA.

[0078] The display panel DP includes a display area DA for displaying an image and a non-display area NDA adjacent to the display area DA. In some embodiments of the present invention, the non-display area NDA may surround the display area DA. However, this is shown by way of example, and the non-display area NDA may be defined in various shapes and is not limited to any one embodiment. In some embodiments of the present invention, the display area DA of the display panel DP may correspond to at least a portion of the transmissive area TA.

[0079] The upper module UM may include various components. According to some embodiments of the present invention, the upper module UM may include an anti-reflective layer RPL and an input sensor layer ISP.

[0080] The anti-reflective layer RPL can be disposed on the display panel DP. The anti-reflective layer RPL can be arranged together with the display panel DP around the first folding axis FX1 (see...). Figure 1 ) or the second folding axis FX2 (see Figure 1 (Bend or fold)

[0081] An anti-reflective layer (RPL) can prevent or reduce the visual recognition or perception of components constituting or forming a display panel (DP) from the outside by external light incident through the front surface of the display device (DD). The RPL may include a polarizing film and / or a phase retardation film. The number of phase retardation films and the phase retardation length (λ / 4 or λ / 2) of the phase retardation films can be determined according to the operating principle of the RPL. However, embodiments of the invention are not limited thereto, and the RPL may include a plurality of color filters and a light-blocking pattern arranged between the color filters.

[0082] The input sensor layer (ISP) can sense external input using capacitive, pressure-sensing, or electromagnetic induction methods. The ISP can be formed on the display panel (DP) using a continuous process. Alternatively, the ISP and DP can be bonded to each other using an adhesive film. In this case, the ISP can be manufactured separately from the process used for the DP, and then bonded to the upper surface of the DP using an adhesive film, rather than being manufactured together with the DP using a continuous process.

[0083] Window WM can be generated by image IM (see Figure 1 It is made of a transparent material that can be passed through. For example, the window WM can be made of glass, sapphire, or plastic. The window WM is shown as a single layer, but embodiments according to this disclosure are not limited thereto and the window WM may include multiple layers.

[0084] The upper surface of the window WM defines the display surface IS of the display device DD. The window WM can be optically transparent. Therefore, the user can easily recognize the image generated by the display panel DP through the window WM.

[0085] Meanwhile, the bezel area BZA of the aforementioned display device DD can be substantially provided as an area in which a material containing color (e.g., a set or predetermined color) is printed on an area of ​​the window WM. According to some embodiments of the present invention, the window WM may include a light-blocking pattern for defining the bezel area BZA. The light-blocking pattern is a colored organic film and can be formed by, for example, a coating method. In other words, corresponding to the transmissive area TA and the bezel area BZA of the display device DD, the window WM may also include a transmissive area TA and a bezel area BZA adjacent to the transmissive area TA, through which light passes.

[0086] The window WM can be made of a soft material. Therefore, the window WM can be folded or unfolded around the first folding axis FX1 or the second folding axis FX2. That is, when the shape of the display module DM is changed, the shape of the window WM can change along with the display module DM. In other words, the window WM can be configured to fold together with the display panel DP.

[0087] According to some embodiments of the present invention, the window WM may comprise flexible glass or a synthetic resin film. For example, when the window WM comprises flexible glass, the thickness of the glass may be approximately 80 μm or less. Therefore, the flexible glass may be referred to as thin-film glass. For example, the thickness of the window WM may be approximately 30 μm, but the thickness of the window WM is not limited to this. When the window WM comprises a synthetic resin film, the window WM may comprise a polyimide (PI) film or a polyethylene terephthalate (PET) film. When the window WM comprises a synthetic resin film, the thickness of the window WM may be approximately 50 μm. The window WM may have a multilayer structure or a single-layer structure. Hereinafter, the window WM is described as comprising thin-film glass.

[0088] The window WM can be coupled to the display module DM via an adhesive film. According to some embodiments of the present invention, the adhesive film may include an optically clear adhesive (OCA) film. However, the adhesive film is not limited to this and may include conventional adhesives or glues. For example, the adhesive film may include an optically clear resin (OCR) film or a pressure-sensitive adhesive (PSA) film.

[0089] Reference Figure 4B The display module DM may include a recessed portion HM. According to some embodiments of the present invention, the recessed portion HM may be included in the folding region FA. In the following description, only the folding region FA foldable along the second folding axis FX2 is shown. However, embodiments of the present invention are not limited thereto and can be applied to regions including those foldable along the first folding axis FX1 (see...). Figure 1 A display device with a foldable foldable area.

[0090] According to some embodiments of the present invention, the recessed portion HM can be included in the non-display area NDA. The recessed portion HM does not overlap with the display area DA of the displayed image.

[0091] According to some embodiments of the present invention, the recessed portion HM is spaced apart from the transmissive region TA of the window WM. The recessed portion HM does not overlap with the transmissive region TA but overlaps with the border region BZA. Due to the light-blocking pattern included in the border region BZA, the recessed portion HM can be visually undetectable by the user.

[0092] The shape and formation steps of the recessed portion HM will be referred to later. Figures 9A to 12B Describe it.

[0093] When the direction parallel to the second folding axis FX2 is referred to as the reference direction, in the reference direction, the window WM has a first width W1 in the non-folded region NFA and a second width W2 in the folded region FA. According to some embodiments of the invention, the first width W1 and the second width W2 may be the same as each other. However, embodiments of the invention are not limited thereto, and the second width W2 may be smaller than the first width W1.

[0094] The multiple side surfaces DD_S of the display device DD include the multiple side surfaces DM_S of the display module DM and the multiple side surfaces WM_S of the window WM.

[0095] According to some embodiments of the present invention, the multiple side surfaces DM_S of the display module DM include a first module side surface DM_S1 and a second module side surface DM_S2.

[0096] According to some embodiments of the present invention, the first module side surface DM_S1 may be one of the plurality of side surfaces DM_S of the display module DM that overlaps with the folded region FA. The second module side surface DM_S2 may be one of the plurality of side surfaces DM_S of the display module DM that overlaps with the first non-folded region NFA1 and the second non-folded region NFA2. However, embodiments of the present invention are not limited thereto, and the first module side surface DM_S1 may include at least a portion overlapping with the folded region FA. According to some embodiments of the present invention, the first module side surface DM_S1 may further include portions of the plurality of side surfaces DM_S of the display module DM that overlap with some of the first non-folded regions NFA1 and the second non-folded regions NFA2.

[0097] The multiple side surfaces WM_S of window WM include a first window side surface WM_S1 and a second window side surface WM_S2. The first window side surface WM_S1 may be a side surface that overlaps with the folded region FA, and the second window side surface WM_S2 may be a side surface that overlaps with the non-folded region NFA.

[0098] Figure 5A It is along Figure 4B The cross-sectional view of the folded region intercepted by line I-I' is shown in the figure. Figure 5B It is along Figure 4B The cross-sectional view of the non-folded region intercepted by line II-II' is shown in the figure. To clearly illustrate the correspondence of the main structures, Figure 4B The anti-reflective layer RPL and the input sensor layer ISP are not shown in the diagram, but... Figure 5A and Figure 5B The image shows the anti-reflective layer RPL and the input sensor layer ISP.

[0099] Reference Figures 4B to 5BThe side surface of the display device DD that overlaps with the folded region FA among its multiple side surfaces DD_S is referred to as the first device side surface DD_S1. The first device side surface DD_S1 includes the first module side surface DM_S1 and the first window side surface WM_S1. The side surface of the display device DD that overlaps with the non-folded region NFA among its multiple side surfaces DD_S is referred to as the second device side surface DD_S2. The second device side surface DD_S2 includes the second module side surface DM_S2 and the second window side surface WM_S2.

[0100] Among the multiple side surfaces of the display panel DP, the side surface overlapping the folded region FA is referred to as the first panel side surface DP_S1, and the side surface overlapping the non-folded region NFA is referred to as the second panel side surface DP_S2. Similarly, among the multiple side surfaces of the input sensor layer ISP, the side surface overlapping the folded region FA is referred to as the first sensor side surface ISP_S1, and the side surface overlapping the non-folded region NFA is referred to as the second sensor side surface ISP_S2. Likewise, among the multiple side surfaces of the anti-reflective layer RPL, the side surface overlapping the folded region FA is referred to as the first anti-reflective side surface RPL_S1, and the side surface overlapping the non-folded region NFA is referred to as the second anti-reflective side surface RPL_S2.

[0101] According to some embodiments of the present invention, the first module side surface DM_S1 includes a first panel side surface DP_S1, a first sensor side surface ISP_S1, and a first anti-reflective side surface RPL_S1. Additionally, the second module side surface DM_S2 includes a second panel side surface DP_S2, a second sensor side surface ISP_S2, and a second anti-reflective side surface RPL_S2.

[0102] However, when the adhesive layer is located between the display panel DP and the input sensor layer ISP, or between the input sensor layer ISP and the anti-reflective layer RPL, the first module side surface DM_S1 and the second module side surface DM_S2 may also include the side surface of the adhesive layer.

[0103] When the degree of irregularity of the pattern formed on the processed surface is referred to as surface roughness, the first window-side surface WM_S1 has a first window surface roughness WM_SR1, and the second window-side surface WM_S2 has a second window surface roughness WM_SR2.

[0104] The surface roughness WM_SR1 of the first window can be defined as the average height from the reference surface RS to the first window side surface WM_S1 in the folded region FA. The surface roughness WM_SR2 of the second window can be defined as the average height from the reference surface RS to the second window side surface WM_S2 in the unfolded region NFA. According to some embodiments of the present invention, the surface roughness WM_SR1 and the surface roughness WM_SR2 of the first window can be identical to each other.

[0105] The first module side surface DM_S1 has a first module surface roughness DM_SR1, and the second module side surface DM_S2 has a second module surface roughness DM_SR2. The first module surface roughness DM_SR1 can be defined as the average height from the reference surface RS to the first module side surface DM_S1 in the folded region FA. The second module surface roughness DM_SR2 can be defined as the average height from the reference surface RS to the second module side surface DM_S2 in the unfolded region NFA. According to some embodiments of the present invention, the first module surface roughness DM_SR1 can be lower than the second module surface roughness DM_SR2.

[0106] The surface roughness DM_SR1 of the first module can be the average of the surface roughness DP_SR1 of the first panel (the surface roughness DP_SR1 of the first panel is the surface roughness of the first panel side surface DP_S1), the surface roughness ISP_SR1 of the first sensor (the surface roughness ISP_SR1 of the first sensor is the surface roughness of the first sensor side surface ISP_S1), and the surface roughness RPL_SR1 of the first anti-reflective surface (the surface roughness RPL_SR1 of the first anti-reflective side surface RPL_S1).

[0107] The second module surface roughness DM_SR2 can be the average of the second panel surface roughness DP_SR2 (the second panel surface roughness DP_SR2 is the surface roughness of the second panel side surface DP_S2), the second sensor surface roughness ISP_SR2 (the second sensor surface roughness ISP_SR2 is the surface roughness of the second sensor side surface ISP_S2), and the second anti-reflective surface roughness RPL_SR2 (the second anti-reflective surface roughness RPL_SR2 is the surface roughness of the second anti-reflective side surface RPL_S2).

[0108] According to some embodiments of the present invention, the surface roughness DP_SR1 of the first panel can be lower than that of the surface roughness DP_SR2 of the second panel.

[0109] The surface roughness of the first sensor, ISP_SR1, can be lower than that of the second sensor, ISP_SR2.

[0110] The first anti-reflective surface roughness RPL_SR1 can be lower than the second anti-reflective surface roughness RPL_SR2.

[0111] By following the first cutting line CL1 (see...) Figure 7A The first cutting process is performed to process and form the second module side surface DM_S2 that overlaps with the non-folded region NFA. This is done along the second cutting line CL2 (see...). Figure 8A The second cutting process is performed to process and form the first module side surface DM_S1 that overlaps with the folded region FA.

[0112] The area of ​​a surface damaged during the cutting process is called the heat-affected zone (HAZ). The wider the HAZ, the greater the potential damage to the surface and the higher the surface roughness.

[0113] According to some embodiments of the present invention, the heat-affected zone caused by the first cutting process can be referred to as the first heat-affected zone HAZ1, and the heat-affected zone caused by the second cutting process can be referred to as the second heat-affected zone HAZ2. When the width of the first heat-affected zone HAZ1 in the first direction DR1 is referred to as the first heat-affected width HAW1 and the width of the second heat-affected zone HAZ2 in the first direction DR1 is referred to as the second heat-affected width HAW2, the first heat-affected width HAW1 can be greater than the second heat-affected width HAW2. Therefore, the first module surface roughness DM_SR1 of the first module side surface DM_S1 processed by the second cutting process can be lower than the second module surface roughness DM_SR2 of the second module side surface DM_S2 processed by the first cutting process.

[0114] In contrast, the first window-side surface WM_S1 and the second window-side surface WM_S2 can be formed by the same cutting process. Therefore, the width HAW3 of the heat-affected zone HAZ3 formed on the first window-side surface WM_S1 in the first direction DR1 can be the same as the width HAW3 of the heat-affected zone HAZ3 formed on the second window-side surface WM_S2 in the first direction DR1. Therefore, the first window-side surface WM_S1 can have the same surface roughness as the second window-side surface WM_S2.

[0115] Figure 6 It is a photograph of the side surface of the display module positioned in the folded and non-folded areas.

[0116] Reference Figure 6The surface roughness of the first module side surface DM_S1, where the display module DM is located in the folded region FA, is lower than the surface roughness of the second module side surface DM_S2, where the display module DM is located in the first non-folded region NFA1 and the second non-folded region NFA2. That is, relatively small and regular bumps are formed on the first module side surface DM_S1, while relatively large and irregular bumps are formed on the second module side surface DM_S2.

[0117] Small and large black dots BD are visually identified on the second module side surface DM_S2. Here, the black dot BD may be a recessed portion of the second module side surface DM_S2, and the relatively bright portion around the black dot BD may be a protruding portion of the second module side surface DM_S2. In some embodiments of the present invention, the black dot BD may be located on the antireflective layer RPL (see...). Figure 5B However, embodiments of the present invention are not limited thereto. The black dot BD can be located both on the anti-reflective layer RPL and on the display panel DP (see [reference]). Figure 5B ) on or into the sensor layer ISP (see Figure 5B )superior.

[0118] On the other hand, the difference in brightness at the location on the first module side surface DM_S1 is not significant, and almost no black spots can be detected. Therefore, it can be seen that the first module side surface DM_S1 has a lower surface roughness than the second module side surface DM_S2.

[0119] Figures 7A to 7C This is a process diagram illustrating a first cutting process according to some embodiments of the concept of the present invention, and Figures 8A to 8C This is a process diagram illustrating a second cutting process according to some embodiments of the concept of the present invention.

[0120] Reference Figures 7A to 8C Prepare a parent substrate MG comprising multiple cell regions CE. Each cell region CE includes a valid region AA and an invalid region NAA.

[0121] Each preliminary display module (PDM) is obtained from the parent substrate (MG) by performing a first cutting process along the first cutting line CL1 surrounding each unit region (CE).

[0122] The first cutting process can be performed using a first laser LD1 having a first wavelength. According to some embodiments of the invention, the first laser LD1 can be generated using carbon dioxide as a medium, and the first wavelength can be from approximately 1000 nm to approximately 1400 nm. The first cutting process can be performed by repeatedly irradiating the first laser LD1 n times, where n is a natural number greater than 1. The first laser LD1 can be irradiated at a first frequency and at a first power.

[0123] According to some embodiments of the present invention, the first cutting process can be performed by moving the mother substrate MG while the position of the first laser LD1 is fixed.

[0124] Reference Figure 8A Each preliminary display module (PDM) obtained through the first cutting process is prepared. The invalid region NAA can be removed from the valid region AA by performing a second cutting process along the second cutting line CL2 located at the boundary between the valid region AA and the invalid region NAA included in each preliminary display module PDM.

[0125] The second cutting process can be performed using a second laser LD2 having a second wavelength different from the first wavelength. In some embodiments of the invention, the second wavelength can be shorter than the first wavelength. The second wavelength can be approximately 300 nm to approximately 400 nm. The second cutting process can be performed by repeatedly irradiating the target area m times with the second laser LD2. In some embodiments of the invention, m can be a natural number greater than n.

[0126] The second laser LD2 can be irradiated at a second frequency. In some embodiments of the present invention, the second frequency can be greater than the first frequency. The second laser LD2 can be irradiated at a second power. In some embodiments of the present invention, the second power can be less than the first power.

[0127] According to some embodiments of the present invention, the second cutting process can be performed by moving the second laser LD2 while the position of each preliminary display module (PDM) is fixed. According to some embodiments of the present invention, the second cutting process can be performed as long as the second laser LD2 can perform the second cutting process along the second cutting line CL2. That is, although the size of the preliminary display module (PDM) increases, the length of the second cutting line CL2 is limited by the boundary between the ineffective region NAA and the effective region AA. Therefore, even if the size of the preliminary display module (PDM) is changed, it is not necessary to replace the device to perform the second cutting process. Furthermore, because the second cutting process is performed only at the portion where the effective region AA and the ineffective region NAA contact each other, the processing time can be shortened.

[0128] Figure 7B and Figure 7C It is along Figure 7A The cross-sectional view taken by line III-III' is shown in the figure. (Refer to...) Figure 7B and Figure 7C The parent substrate MG may include a preliminary display panel (PDP) and a preliminary input sensor layer (PIS). However, according to some embodiments of the present invention, the parent substrate MG may not include the preliminary input sensor layer (PIS).

[0129] The first heat-affected zone (HAZ1) is formed adjacent to the side surface PDM_S of the preliminary display module PDM obtained by performing a first cutting process along the first cutting line CL1 using a first laser LD1. The first heat-affected zone HAZ1 includes a first sub-heat-affected zone HAZ1_a formed adjacent to the side surface of the input sensor layer ISP and a second sub-heat-affected zone HAZ1_b formed adjacent to the side surface of the display panel DP. The first sub-heat-affected zone HAZ1_a and the second sub-heat-affected zone HAZ1_b may have the same width in the first direction DR1. However, the widths of the first sub-heat-affected zone HAZ1_a and the second sub-heat-affected zone HAZ1_b in the first direction DR1 can vary depending on the materials contained in the input sensor layer ISP and the display panel DP.

[0130] According to some embodiments of the present invention, the width NAW of the invalid region NAA in the first direction DR1 (see...) Figure 9A The width of the first heat-affected zone HAZ1 in the first direction DR1 can be greater than or equal to the width of the first heat-affected zone HAW1 (see [reference]). Figure 9A ).

[0131] Figure 8B and Figure 8C It is along Figure 8A The cross-sectional view taken along line IV-IV' is shown in the figure. (Refer to...) Figure 8B and Figure 8C Each preliminary display module (PDM) may also include an anti-reflective layer (RPL). The RPL can be placed on the input sensor layer (ISP). Although Figure 8B The width of the third sub-heat-affected zone HAZ1_c generated on the side surface of the anti-reflective layer RPL in the first direction DR1 is the same as the width of the first sub-heat-affected zone HAZ1_a and the second sub-heat-affected zone HAZ1_b in the first direction DR1, but the width of the third sub-heat-affected zone HAZ1_c in the first direction DR1 may be different from the width of the first sub-heat-affected zone HAZ1_a and the second sub-heat-affected zone HAZ1_b in the first direction DR1.

[0132] By using the second laser LD2 to perform a second cutting process along the second cutting line CL2, a display module DM in which the invalid region NAA is removed from the valid region AA of the initial display module PDM can be obtained.

[0133] A second heat-affected zone (HAZ2) is formed on the first module side surface DM_S1 of the display module DM obtained by performing a second cutting process. The second heat-affected zone HAZ2 includes a fourth sub-heat-affected zone HAZ2_a formed adjacent to the side surface of the input sensor layer ISP, a fifth sub-heat-affected zone HAZ2_b formed adjacent to the side surface of the display panel DP, and a sixth sub-heat-affected zone HAZ2_c formed adjacent to the side surface of the anti-reflective layer RPL. The widths of the fourth sub-heat-affected zone HAZ2_a, the fifth sub-heat-affected zone HAZ2_b, and the sixth sub-heat-affected zone HAZ2_c in the first direction DR1 can be the same. However, depending on the materials contained in the input sensor layer ISP, the display panel DP, and the anti-reflective layer RPL, the widths of the fourth sub-heat-affected zone HAZ2_a, the fifth sub-heat-affected zone HAZ2_b, and the sixth sub-heat-affected zone HAZ2_c in the first direction DR1 can be different.

[0134] Because the second cutting process is performed by a laser LD1 with the same characteristics as the first laser (see...). Figure 7A The first power of the second laser LD2 is performed compared to the relatively smaller second power, so a smaller heat-affected width HAW1 can be formed (see [link]). Figure 5B The second thermally affected width HAW2 (see) Figure 5A ).

[0135] Therefore, when a second cutting process is performed along the second cutting line CL2 after the first cutting process is performed to obtain a preliminary display module PDM including an effective area AA and an invalid area NAA that is preset to include an area extending from any area of ​​the display module DM, the display module DM in which the second heat-affected zone HAZ2 is generated can be obtained in the effective area AA that is in contact with the invalid area NAA.

[0136] According to some embodiments of the present invention, the invalid region NAA may at least include the folded region FA from the display module DM (see...). Figure 9B The region extending from the non-folded region NFA (see [reference]). However, embodiments of the present invention are not limited thereto, and the invalid region NAA may include the region extending from the non-folded region NFA (see [reference]). Figure 9B (a region that extends from a part of the area.)

[0137] When the invalid region NAA includes the folded region FA (see...) Figure 9B When the region extends, the first heat-affected zone HAZ1 is formed in the non-folded region NFA in which only the first cutting process is performed (see [link]). Figure 9B In the first module side surface DM_S1, the second heat-affected zone HAZ2 is formed in the folded region FA in which the first and second cutting processes are performed. Therefore, the first module surface roughness DM_SR1 (see...) is... Figure 5AIt can be below the second module side surface DM_S2 (see...) Figure 4B The second module, surface roughness DM_SR2 (see...) Figure 5B ).

[0138] Therefore, damage to the display module DM due to stress applied to the first module side surface DM_S1 caused by repeated folding operations can be prevented or reduced. As a result, the display device DD (see...) can be improved. Figure 1 Product reliability.

[0139] Figures 9A to 12B This is a plan view illustrating a second cutting process according to some embodiments of the concept of the present invention.

[0140] Reference Figure 9A and Figure 9B The invalid region NAA can be rectangular. The second cutting line CL2 is located at the boundary between the invalid region NAA and the valid region AA.

[0141] The effective area AA includes the display area DA and the non-display area NDA. The display module DM may include a first recessed portion HM1. The first recessed portion HM1 can be formed by removing the ineffective area NAA from the effective area AA by a second cutting process. The first recessed portion HM1 may have a rectangular shape corresponding to the ineffective area NAA, which has a rectangular shape.

[0142] According to some embodiments of the present invention, when the invalid region NAA includes a region extending from the folded region FA, the first recessed portion HM1 may be located in the region extending from the folded region FA.

[0143] In the reference direction, the display module DM has a third width W3 in the non-folded region NFA and a fourth width W4 in the folded region FA. According to some embodiments of the present invention, when the display module DM includes a first recessed portion HM1, the fourth width W4 may be smaller than the third width W3.

[0144] Reference Figure 10A and Figure 10B The invalid region NAA can have a polygonal shape other than a rectangle. According to some embodiments of the present invention, the invalid region NAA can have a trapezoidal shape.

[0145] The display module DM may include a second recessed portion HM2. The second recessed portion HM2 may have a trapezoidal shape corresponding to the inactive region NAA, which has a trapezoidal shape.

[0146] According to some embodiments of the present invention, when the invalid region NAA includes a region extending from the folded region FA, the second recessed portion HM2 may be located in the region extending from the folded region FA.

[0147] Reference Figure 11A and Figure 11B The invalid region NAA includes: a first invalid region NAA_a extending from the folded region FA; and a second invalid region NAA_b extending from a corner portion that is part of the unfolded region NFA. At least one of the first invalid region NAA_a and the second invalid region NAA_b may have a curved shape.

[0148] The second cutting line CL2 includes a first sub-cutting line CL2_a located at the boundary between the valid region AA and the first invalid region NAA_a, and a second sub-cutting line CL2_b located at the boundary between the valid region AA and the second invalid region NAA_b.

[0149] The display module DM may include a third recessed portion HM3. The third recessed portion HM3 can be formed by removing a first invalid region NAA_a from the valid region AA using a second cutting process. The third recessed portion HM3 may have a curved shape corresponding to the first invalid region NAA_a, which has a curved shape.

[0150] According to some embodiments of the present invention, the display module DM may have a curved shape at its corners. This curved shape can be formed by removing a second invalid region NAA_b from the effective region AA using a second cutting process. When the invalid region NAA is configured to include both the second invalid region NAA_b and the first invalid region NAA_a, the second cutting process enables obtaining the desired shape of the display module DM, in addition to preventing or reducing damage to the display module DM during folding operations.

[0151] Reference Figure 12A and Figure 12B The invalid region NAA can extend from the folded region FA and can have a shape that protrudes from the valid region AA. According to some embodiments of the invention, the invalid region NAA can have a curved shape and protrude.

[0152] When the invalid region NAA has a shape that protrudes from the valid region AA, the display module DM may not include a recessed portion. The display module DM from which the invalid region NAA is removed by a second cutting process may have a rectangular shape. However, even in this case, when the second module side surface DM_S2 overlaps with the non-folded region NFA (see...) Figure 4B In comparison, the multiple side surfaces DM_S of the display module DM (see...) Figure 4BThe first module side surface DM_S1 that overlaps with the folded region FA (see) Figure 4B It can have a relatively low surface roughness. Therefore, by preventing or reducing damage to the display module DM during the folding operation, product reliability can be improved.

[0153] According to some embodiments of the present invention, in order to reduce stress applied to the side surfaces of the display panel and damage to the side surfaces of the display panel, a cutting process using a low-energy laser can be performed along a cutting line located at least in the folding region. Therefore, even if the size of the display panel increases, a cutting process using a low-energy laser can be performed in the folding region without moving the laser device. Thus, the folding reliability of the display device can be improved by reducing defects such as cracks in the folding region during the folding operation of the display device.

[0154] While aspects of embodiments of the invention have been described with reference to some exemplary embodiments thereof, it will be understood by those skilled in the art or of ordinary skill in the art that various modifications and changes may be made to the invention without departing from the spirit and scope of the invention as described in the claims and their equivalents.

[0155] Therefore, the technical scope of the embodiments of the present invention should not be limited to what is described in the detailed description of this specification, but should be determined by the claims and their equivalents.

Claims

1. A display device, wherein, The display device includes: The display panel includes a folding region configured to be foldable about a folding axis and a non-folding region adjacent to the folding region; and A window, located on the display panel and configured to fold together with the display panel. in: The side surface of the display panel has a first surface roughness in the folded area and a second surface roughness in the non-folded area; The first surface roughness is lower than the second surface roughness; The side surface of the window has the same surface roughness in both the non-folded and folded regions; and In the folded region, the surface roughness of the side surface of the window is different from the first surface roughness of the side surface of the display panel.

2. The display device as claimed in claim 1, wherein, The window comprises thin-film glass.

3. The display device as claimed in claim 1, wherein, The display device also includes an anti-reflective layer on the display panel and foldable together with the display panel.

4. The display device as claimed in claim 3, wherein: The side surface of the antireflective layer has a third surface roughness in the folded region and a fourth surface roughness in the unfolded region; and The third surface roughness is lower than the fourth surface roughness.

5. The display device as claimed in claim 1, wherein: The display panel includes a recessed portion in the folded area; When the direction of the folding axis is referred to as the reference direction, the display panel has a first width in the non-folded area and a second width in the folded area in the reference direction; and The second width is smaller than the first width.

6. The display device as claimed in claim 5, wherein, The recessed portion includes a curved shape.

7. The display device as claimed in claim 5, wherein, In the reference direction, the window has the same width in the folded area and in the non-folded area.

8. The display device as claimed in claim 7, wherein: The window includes a transmissive area and a border area adjacent to the transmissive area, through which light passes; and The recessed portion is spaced apart from the transmission region.

9. A display device, wherein, The display device includes: The display panel includes a folding region configured to be foldable about a folding axis and a non-folding region adjacent to the folding region; and A window, located on the display panel and configured to be foldable together with the display panel. in: The multiple side surfaces of the display panel include a first side surface having a first surface roughness and a second side surface having a second surface roughness higher than the first surface roughness; The side surface of the window has the same surface roughness in both the non-folded and folded regions; The first side surface includes at least one of the plurality of side surfaces of the display panel that overlaps with the folded region; In the folded region, the surface roughness of the side surface of the window is different from the first surface roughness of the side surface of the display panel.

10. The display device as claimed in claim 9, wherein, The window comprises thin-film glass.

11. The display device as claimed in claim 9, wherein, The first side surface has a curved shape.

12. The display device as claimed in claim 9, wherein, The first side surface also includes one of the plurality of side surfaces of the display panel that overlaps with a portion of the non-folded region.

13. The display device as claimed in claim 9, wherein, The display device also includes an anti-reflective layer on the display panel and foldable together with the display panel. in: The side surface of the antireflective layer includes a third side surface with a third surface roughness and a fourth side surface with a fourth surface roughness higher than the third surface roughness; and The third side surface overlaps with the first side surface.

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