CN111580210A - Optical member and display apparatus including the same - Google Patents

Abstract

The present application relates to an optical member and a display apparatus. The optical member includes a light guide plate including an upper face, a first side face, and a first inclined face disposed between the upper face and the first side face, a wavelength conversion layer disposed on the upper face of the light guide plate, and a first reflection band including a first side portion covering the first side face and a first folding portion extending from one end of the first side portion and covering the first inclined face. The side surface of the wavelength conversion layer is disposed more inward than a boundary between the upper face and the first inclined face, and the first side portion includes a reflective layer and the first folded portion includes a light absorbing layer.

Description

Optical member and display apparatus including the same

Cross Reference to Related Applications

This application claims priority and benefit from korean patent application No. 10-2019-0019139, filed on 19.2.2019, which is incorporated herein by reference for all purposes as if fully set forth herein.

Technical Field

Exemplary embodiments of the present invention relate to an optical member and a display apparatus including the same.

Background

A Liquid Crystal Display (LCD) receives light from the backlight assembly and displays an image. Some backlight assemblies include a light source and a light guide plate. The light guide plate receives light from the light source and guides the light such that it propagates toward the display panel. In some display devices, the light source provides white light, and the white light is filtered through color filters in the display panel to render colors.

Recently, in order to improve image quality of display devices, such as color gamut, application of wavelength conversion films to liquid crystal display devices is being studied. In general, a blue light source may be used as the light source, and a wavelength conversion film is disposed over the light guide plate to convert the blue light into white light. If light emitted from the blue light source leaks through the side surface of the light guide plate, a user may recognize it due to the light leakage.

The above information disclosed in this background section is only for background understanding of the inventive concept and, therefore, it may include information that does not constitute prior art.

Disclosure of Invention

Exemplary embodiments of the present invention provide an optical member capable of preventing defects due to leakage of incident light.

Exemplary embodiments of the present invention also provide a display apparatus including an optical member capable of preventing defects due to leakage of incident light.

Additional features of the inventive concept will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the inventive concept.

An exemplary embodiment of the present invention provides an optical member including a light guide plate, a wavelength conversion layer, and a first reflection band, wherein the light guide plate includes an upper face, a first side face, and a first inclined face disposed between the upper face and the first side face, the wavelength conversion layer is disposed on the upper face of the light guide plate, and the first reflection band includes a first side portion covering the first side face, and a first folding portion extending from one end of the first side portion and covering the first inclined face. The side surface of the wavelength conversion layer is disposed more inward than a boundary between the upper face and the first inclined face, and the first side portion includes a reflective layer and the first folded portion includes a light absorbing layer.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the inventive concept.

Fig. 1 is a perspective view of an optical member and a light source according to an exemplary embodiment of the present invention.

Fig. 2 is a sectional view taken along line X1-X1' in fig. 1.

Fig. 3A and 3B are views illustrating a variation of the exemplary embodiment illustrated in fig. 2.

Fig. 4A and 4B are cross-sectional views of low refractive index layers according to various exemplary embodiments of the present invention.

Fig. 5 is a plan view of a reflection band according to an exemplary embodiment of the present invention.

Fig. 6 is a sectional view taken along line X2-X2' of fig. 5.

Fig. 7, 8 and 9 are plan views of reflection bands according to various exemplary embodiments.

Fig. 10 and 11 are views showing a modification of the structure shown in fig. 6.

Fig. 12 is a sectional view of an optical member according to another exemplary embodiment of the present invention.

Fig. 13 is a sectional view of an optical member according to still another exemplary embodiment of the present invention.

Fig. 14 is a plan view of the reflection band of fig. 13.

FIG. 15 is a cross-sectional view of the reflective tape taken along line X3-X3' of FIG. 14.

Fig. 16 is a perspective view of an optical member and a light source according to an exemplary embodiment of the present invention.

Fig. 17 is a sectional view of the optical member taken along line X4-X4' of fig. 16.

Fig. 18 is a sectional view of a display apparatus according to an exemplary embodiment of the present invention.

Detailed Description

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of various exemplary embodiments of the invention. As used herein, "embodiments" and "implementations" are interchangeable words, which are non-limiting examples of devices or methods that employ one or more of the inventive concepts disclosed herein. It may be evident, however, that the various exemplary embodiments may be practiced without these specific details or with one or more equivalent arrangements. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the various exemplary embodiments. Moreover, the exemplary embodiments may be different, but not necessarily exclusive. For example, the particular shapes, configurations and characteristics of the exemplary embodiments may be used or carried out in another exemplary embodiment without departing from the inventive concept.

Unless otherwise indicated, the illustrated exemplary embodiments are to be construed as exemplary features providing different details of some ways in which the inventive concepts may be practiced. Thus, unless otherwise indicated, features, components, modules, layers, films, panels, regions, and/or aspects and the like (individually or collectively, "elements" hereinafter) of the various embodiments may be otherwise combined, separated, interchanged, and/or rearranged without departing from the inventive concepts.

The use of cross-hatching and/or shading in the drawings is generally employed to clarify the boundaries between adjacent elements. As such, unless otherwise specified, the presence or absence of cross-sectional lines or shading does not convey or indicate any preference or requirement for a particular material, material property, dimension, proportion, commonality between the illustrated elements, and/or any other characteristic, attribute, property, etc., of an element. Further, in the drawings, the size and relative sizes of elements may be exaggerated for clarity and/or descriptive purposes. While example embodiments may perform differently, certain process sequences may be performed differently than those described. For example, two processes described in succession may be executed substantially concurrently or in the reverse order to that described. In addition, like reference numerals denote like elements.

When an element such as a layer is referred to as being "on," "connected to," or "coupled to" another element or layer, it can be directly on, connected or coupled to the other element or layer, or intervening elements or layers may be present. However, when an element or layer is referred to as being "directly on," "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers present. To this end, the term "connected" may mean physically, electrically, and/or fluidically connected, with or without intervening elements. Further, the D1 axis, the D2 axis, and the D3 axis are not limited to three axes of a rectangular coordinate system, such as an x-axis, a y-axis, and a z-axis, and may be interpreted in a broader sense. For example, the D1, D2, and D3 axes may be perpendicular to each other, or may represent different directions that are not perpendicular to each other. For purposes of this disclosure, "at least one of X, Y and Z" and "at least one selected from the group consisting of X, Y and Z" can be construed as X only, Y only, Z only, or any combination of two or more of X, Y and Z, such as, for example, XYZ, XYY, YZ, and ZZ. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Although the terms first, second, etc. may be used herein to describe various types of elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. Thus, a first element discussed below could be termed a second element without departing from the teachings of the present disclosure.

Spatially relative terms, such as "below", "over", "under", "lower", "over", "high", "side", etc. (e.g., as in "sidewall") may be used herein for descriptive purposes and thus may be used to describe one element's relationship to another element(s) as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use, operation, and/or manufacture in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. Moreover, the device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and, as such, the spatially relative descriptors used herein should be interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, the terms "comprises," "comprising," "including," "includes" and/or "including," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It is further noted that, as used herein, the terms "substantially," "about," and other similar terms are used as approximate terms and not as degree terms, and as such, are used to set aside margins for inherent deviations in measured, calculated, and/or provided values that would be recognized by one of ordinary skill in the art.

Exemplary embodiments are described herein with reference to cross-sectional and/or exploded views as illustrations of idealized exemplary embodiments and/or intermediate structures. Thus, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, the exemplary embodiments disclosed herein should not necessarily be construed as limited to the shapes of regions specifically illustrated, but should include deviations in shapes that result, for example, from manufacturing. In this manner, the regions illustrated in the figures may be schematic in nature and the shapes of these regions may not reflect the actual shape of a region of a device and, as such, are not necessarily intended to be limiting.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

Fig. 1 is a perspective view of an optical member and a light source according to an exemplary embodiment of the present invention. Fig. 2 is a sectional view taken along line X1-X1' in fig. 1. Fig. 3A and 3B are views illustrating a variation of the exemplary embodiment illustrated in fig. 2.

Referring to fig. 1, 2 and 3A to 3B, the optical member 100 may include a light guide plate 10, a low refractive index layer 20, a wavelength conversion layer 30, a passivation layer 40 and a reflection band 50, wherein the low refractive index layer 20 is disposed on the light guide plate 10, the wavelength conversion layer 30 is disposed on the low refractive index layer 20, and the passivation layer 40 is disposed on the wavelength conversion layer 30. The light guide plate 10, the low refractive index layer 20, the wavelength conversion layer 30, and the passivation layer 40 may be integrally combined to form the stack structure 11. In other words, the optical member 100 may include the stack structure 11 and the reflection band 50. The reflective tape 50 may cover one side surface of the light guide plate 10. In this case, the top surface of the stack structure 11 may be the upper surface 40a of the passivation layer 40, and the bottom surface of the stack structure 11 may be the lower surface 10b of the light guide plate 10. The stack structure 11 may further include a diffusion pattern 60 disposed on the lower face 10b of the light guide plate 10.

The light guide plate 10 serves to guide a path of light. The light guide plate 10 may have a general polygonal column shape. The shape of the light guide plate 10 may be, but is not limited to, a rectangle when viewed from the top. In an exemplary embodiment, the light guide plate 10 has a substantially hexahedral shape, when viewed from the top, like a rectangle, and the light guide plate 10 may include an upper face 10a, a lower face 10b, and four side faces 10s (10s1, 10s2, 10s3, and 10s 4). In the following description and the drawings, when it is necessary to distinguish one from another, four sides may be respectively represented by "10 s 1", "10 s 2", "10 s 3", and "10 s 4". However, when only one of them is referred to, each of them may be represented by "10 s".

In an exemplary embodiment, the upper face 10a and the lower face 10b of the light guide plate 10 are respectively located on planes, and the plane on which the upper face 10a is located is substantially parallel to the plane on which the lower face 10b is located, so that the light guide plate 10 may have a uniform thickness. However, it is to be understood that the inventive concept is not so limited. The upper face 10a or the lower face 10b may be constituted by a plurality of planes, or the plane in which the upper face 10a is located may intersect the plane in which the lower face 10b is located. For example, the light guide plate 10 may have a wedge shape such that its thickness may become smaller from one side (e.g., a light incident surface) to the other side (e.g., an opposite surface) opposite thereto. Alternatively, the lower face 10b may be inclined upward so that the thickness may be reduced to a certain position toward the other side (e.g., the opposing face) near one side (e.g., the light incident face), and then the upper face 10a and the lower face 10b may become flat.

As shown in fig. 2, the light guide plate 10 may include inclined surfaces 10r between the upper surface 10a and the respective side surfaces 10s and between the lower surface 10b and the respective side surfaces 10 s. In other words, the light guide plate 10 may include chamfered corners. Since the light guide plate 10 includes the chamfered corners, it is possible to alleviate the sharpness of the corners and prevent damage due to external impact. Although the inclined surface 10r is flat in shape as shown in the exemplary embodiment of fig. 1 and 2, in other exemplary embodiments, the inclined surface 10r may be curved.

Fig. 2 shows a structure in which an inclined surface 10r is formed between the upper surface 10a and each side surface 10s of the light guide plate 10 and between the lower surface 10b of the light guide plate 10 and each side surface 10s at each corner. In contrast, referring to fig. 3A and 3B showing modifications, the inclined surface 10r may be formed as a corner between the upper surface 10a of the light guide plate 10 and each side surface 10s or a corner between the lower surface 10B of the light guide plate 10 and each side surface 10 s.

Specifically, referring to fig. 3A, the display device 100a may include inclined surfaces 10r only between the upper surface 10a and the respective side surfaces 10s of the light guide plate 10. For example, the light guide plate 10 may include an inclined surface 10r1a between the upper surface 10a and the light incident surface 10s1 and an inclined surface 10r3a between the upper surface 10a and the opposing surface 10s 3.

Specifically, referring to fig. 3B, the display device 100B may include inclined surfaces 10r only between the lower surface 10B and the respective side surfaces 10s of the light guide plate 10. For example, the light guide plate 10 may include an inclined surface 10r1b between the lower surface 10b and the light incident surface 10s1 and an inclined surface 10r3b between the lower surface 10b and the opposing surface 10s 3.

Although not shown in fig. 3A and 3B, it is to be understood that the inclined surface 10r may also be formed between the upper face 10a or the lower face 10B and other side faces of the light guide plate 10.

In some exemplary embodiments, the plane in which the upper face 10a and/or the lower face 10b of the light guide plate 10 are located may form an angle of about 90 degrees with the plane in which the side face 10s is located. However, in the following description, the light guide plate 10 has inclined surfaces 10r between the upper surface 10a and/or the lower surface 10b and the respective side surfaces 10 s.

In the following description, unless otherwise specified, the inclined surfaces 10r1, 10r2, 10r3, and 10r4 provided adjacent to the respective side surfaces 10s are collectively referred to as the inclined surfaces 10 r.

In the application of the optical member 100, the light source 400 may be disposed adjacent to at least one side surface 10s of the light guide plate 10. Although the plurality of LED light sources 410 mounted on the printed circuit board 420 are disposed adjacent to the side surface 10s1 of the longer side of the light guide plate 10, the inventive concept is not limited thereto. For example, the LED light sources 410 may be disposed adjacent to the sides of the two longer sides 10s1 and 10s3, respectively, or may be disposed adjacent to the side of one of the shorter sides or adjacent to the sides of the two shorter sides 10s2 and 10s4, respectively. In the exemplary embodiment shown in fig. 1, the side face 10s1 (the light source 400 is disposed adjacent to the side face 10s1) of the longer side of the light guide plate 10 serves as a light incident face (denoted by 10s1 in the drawing) on which light is directly incident. The side face 10s3 of the other longer side opposite to the light incident face serves as an opposite face (indicated by 10s3 in the drawing).

The LED light source 410 may emit blue light. In other words, the light emitted from the LED light source 410 may be light having a blue wavelength band. In an exemplary embodiment, the blue light emitted from the LED light source 410 may have a wavelength band between 400 nanometers and 500 nanometers. Blue light emitted from the LED light source 410 may be incident into the light guide plate 10 through the light incident surface 10s 1.

The light guide plate 10 may include an inorganic material. For example, the light guide plate 10 may be made of, but not limited to, glass.

The low refractive index layer 20 is disposed on the upper surface 10a of the light guide plate 10. The low refractive index layer 20 may be directly formed on the upper face 10a of the light guide plate 10 and may be in contact with the upper face 10a of the light guide plate 10. The low refractive index layer 20 is interposed between the light guide plate 10 and the wavelength conversion layer 30 to promote total reflection of the light guide plate 10.

More specifically, in order to efficiently guide light from the light incident surface 10s1 toward the opposing surface 10s3 through the light guide plate 10, it is desirable to perform effective total internal reflection on the upper surface 10a and the lower surface 10b of the light guide plate 10. One of the conditions for achieving total internal reflection in the light guide plate 10 is that the refractive index of the light guide plate 10 is greater than the refractive index of the medium with which the optical interface is formed. As the refractive index of the medium forming the optical interface with the light guide plate 10 decreases, the critical angle for total reflection becomes smaller, so that more total internal reflection can be achieved.

It is assumed that the light guide plate 10 is made of glass having a refractive index of about 1.5. The lower face 10b of the light guide plate 10 is exposed to an air layer having a refractive index of about 1 to form an optical interface with the air layer, and thus, total reflection can be sufficiently achieved.

In contrast, since other optically functional layers are stacked and integrated on the upper face 10a of the light guide plate 10, it is difficult to achieve sufficient total reflection compared to the lower face 10 b. For example, if a material layer having a refractive index of 1.5 or more is stacked on the upper face 10a of the light guide plate 10, it is impossible to achieve total reflection on the upper face 10a of the light guide plate 10. If a material layer having a refractive index slightly smaller than that of the light guide plate 10 (for example, a refractive index of about 1.49) is stacked on the upper face 10a of the light guide plate 10, although total internal reflection may be achieved on the upper face 10a of the light guide plate 10, total reflection is insufficient due to a critical angle being too large. The wavelength conversion layer 30 stacked on the upper face 10a of the light guide plate 10 generally has a refractive index of about 1.5. When such a wavelength conversion layer 30 is directly stacked on the upper face 10a of the light guide plate 10, it is difficult to achieve sufficient total reflection on the upper face 10a of the light guide plate 10.

The low refractive index layer 20 interposed between the light guide plate 10 and the wavelength conversion layer 30 to form an interface with the upper face 10a of the light guide plate 10 has a refractive index lower than that of the light guide plate 10 so that total reflection is performed on the upper face 10a of the light guide plate 10. Further, the low refractive index layer 20 has a refractive index lower than that of the wavelength conversion layer 30 (which is a material layer disposed on the low refractive index layer 20), so that more total reflection can be performed than when the wavelength conversion layer 30 is disposed directly on the upper face 10a of the light guide plate 10.

The difference between the refractive index of the light guide plate 10 and the refractive index of the low refractive index layer 20 may be equal to or greater than 0.2. When the refractive index of the low refractive index layer 20 is smaller than that of the light guide plate 10 by 0.2 or more, sufficient total reflection may be achieved by the upper face 10a of the light guide plate 10. There is no upper limit to the difference between the refractive index of the light guide plate 10 and the refractive index of the low refractive index layer 20. However, the upper limit may be generally 1 or less in consideration of the refractive indices of the materials of the light guide plate 10 and the low refractive index layer 20.

The refractive index of the low refractive index layer 20 may be in the range from 1.2 to 1.4. In general, the manufacturing cost increases exponentially as the refractive index of the solid medium approaches 1. If the refractive index of the low refractive index layer 20 is 1.2 or more, the manufacturing cost can be prevented from increasing excessively. In order to make the critical angle of total reflection of the upper face 10a of the light guide plate 10 sufficiently small, it is advantageous that the refractive index of the low refractive index layer 20 is less than or equal to 1.4. In an exemplary embodiment, a low refractive index layer 20 having a refractive index of about 1.25 may be employed.

The low refractive index layer 20 may include voids to achieve the low refractive index described above. The voids may be made vacuum or may be filled with a layer of air, gas, or the like. The void space may be defined by particles, matrices, and the like. The voids will be described in more detail with reference to fig. 4A and 4B.

Fig. 4A and 4B are cross-sectional views of low refractive index layers according to various exemplary embodiments of the present invention.

In an exemplary embodiment, as shown in fig. 4A, the low refractive index layer 20 may include a plurality of particles PT, a matrix MX, and voids VD, wherein the matrix MX surrounds the particles PT as a single body. The particles PT may be fillers that adjust the refractive index and mechanical strength of the low refractive index layer 20.

The particles PT may be dispersed within the matrix MX in the low refractive index layer 20, and the matrix MX may be partially opened so that voids VD may be formed in the opened portion. For example, the particles PT and the matrix MX may be mixed in a solvent and may then be dried and/or solidified such that the solvent evaporates. In this case, the voids VD may be formed between the open portions of the matrix MX.

In another exemplary embodiment, as shown in fig. 4B, the low refractive index layer 20 may include the matrix MX and the voids VD without particles. For example, the low refractive index layer 20 may include a matrix MX (such as a foamed resin) as a single continuous whole and voids VD formed therein.

As shown in fig. 4A and 4B, when the low refractive index layer 20 (see fig. 2) includes the voids VD, the overall refractive index of the low refractive index layer 20 may be between the refractive index of the particles PT/matrix MX and the refractive index of the voids VD. When the voids VD are in vacuum having a refractive index of 1 or filled with an air layer, a gas, or the like having a refractive index of about 1 as described above, the overall refractive index of the low refractive index layer 20 may have a value of less than or equal to 1.4, for example, about 1.25, even if a material having a refractive index of greater than or equal to 1.4 is used as the particles PT/matrix MX. In an exemplary embodiment, the particles PT consist of e.g. SiO₂、Fe₂O₃And MgF₂And the matrix MX may be made of an organic material such as polysiloxaneThe material is prepared. However, they may be made of other organic or inorganic materials.

Referring back to fig. 1 and 2, the thickness of the low refractive index layer 20 may be in the range from 0.4 μm to 2 μm. In the visible light wavelength range, when the thickness of the low refractive index layer 20 is greater than or equal to 0.4 μm, an effective optical interface may be formed with the upper face 10a of the light guide plate 10, so that total reflection according to snell's law may be promoted on the upper face 10a of the light guide plate 10. If the low refractive index layer 20 is excessively thick, the thickness of the optical member 100 may increase (which is undesirable), the manufacturing cost may increase, and the luminance of the optical member 100 may decrease. Accordingly, the low refractive index layer 20 may have a thickness of less than or equal to 2 μm.

In an exemplary embodiment, the low refractive index layer 20 may cover most of the upper face 10a of the light guide plate 10, and may expose a portion of the edge of the upper face 10a of the light guide plate 10. The upper face 10a of the light guide plate 10 exposed through the low refractive index layer 20 may provide a space in which the side surface 20s of the low refractive index layer 20 may be stably covered by the passivation layer 40.

In another exemplary embodiment, the low refractive index layer 20 may completely cover the upper face 10a of the light guide plate 10. The side surfaces 20s of the low refractive index layer 20 may be aligned with the side surfaces 10s of the light guide plate 10, respectively. Such different exemplary embodiments may be applied according to a manufacturing process of the light guide plate 10.

The low refractive index layer 20 may be formed by coating or the like. For example, the low refractive index layer 20 may be formed by coating a composition for a low refractive index layer on the upper face 10a of the light guide plate 10 followed by drying and curing thereof. The composition for the low refractive index layer may be applied by, but not limited to, slit coating, spin coating, roll coating, spray coating, and inkjet. However, it is to be understood that the compositions may be stacked in a variety of ways.

Although not shown in the drawings, a barrier layer may also be disposed between the low refractive index layer 20 and the light guide plate 10. The blocking layer may cover the entire upper face 10a of the light guide plate 10. The side surfaces of the barrier layers may be aligned with the side surfaces 10s of the light guide plate 10, respectively. A low refractive index layer 20 is formed on top of the barrier layer. The low refractive index layer 20 may expose a portion of the edge of the barrier layer.

The barrier layer serves to prevent permeation of moisture and/or oxygen (hereinafter, referred to as "moisture/oxygen"), like the passivation layer 40, which will be described later. The barrier layer may comprise an inorganic material. For example, the barrier layer may include silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide, titanium oxide, tin oxide, cerium oxide, and silicon oxynitride, or a metal thin film having light transmittance. The barrier layer may be made of, but is not limited to, the same material as the passivation layer 40. The barrier layer may be formed by chemical vapor deposition or the like.

The wavelength conversion layer 30 is disposed on the upper surface 20a of the low refractive index layer 20. The wavelength conversion layer 30 converts the wavelength of at least a portion of the incident light. The wavelength conversion layer 30 may include a bonding layer and wavelength conversion particles dispersed in the bonding layer. In addition to the wavelength converting particles, the wavelength converting layer 30 may also include scattering particles dispersed in the adhesive layer.

The bonding layer is a medium in which wavelength converting particles are dispersed, and may be made of various resin compositions, which may be generally referred to as binders. However, it is to be understood that the inventive concept is not so limited. Any medium may be referred to as a bonding layer regardless of its name, additional other functions, or its constituent material, as long as it can disperse the wavelength converting particles and/or the diffusing particles.

The wavelength converting particles are used to convert the wavelength of incident light, and may be, for example, Quantum Dots (QDs), fluorescent materials, or phosphorescent materials. In the following description, the wavelength converting particles are quantum dots. However, it is to be understood that the inventive concept is not so limited.

Quantum dots are materials having a crystal structure of several nanometers in size, and are composed of hundreds to thousands of atoms. Due to such small size, it exhibits a quantum confinement effect resulting in an increase in the energy band gap. When light having a wavelength with an energy level higher than the band gap is incident on the quantum dot, the quantum dot is excited by absorbing the light and is released to a ground state while emitting light having a specific wavelength. The wavelength of the emitted light has a value corresponding to the band gap. By adjusting the size and composition of the quantum dots, the light emitting characteristics due to the quantum confinement effect can be adjusted.

The quantum dots can include, for example, at least one of: group II-VI compounds, group II-V compounds, group III-VI compounds, group III-V compounds, group IV-VI compounds, group I-III-VI compounds, group II-IV-VI compounds, and group II-IV-V compounds.

The quantum dot may include a core and a shell covering the core. The core may be, but is not limited to, CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InP, InAs, InSb, SiC, Ca, Se, In, P, Fe, Pt, Ni, Co, Al, Ag, Au, Cu, FePt, Fe₂O₃、Fe₃O₄At least one of Si and Ge. The shell may include, but is not limited to, at least one of ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, GaSe, InN, InP, InAs, InSb, TlN, TlP, TlAs, TlSb, PbS, PbSe, and PbTe.

The wavelength converting particles may comprise a plurality of wavelength converting particles that convert incident light to different wavelengths. For example, the wavelength converting particles may include first wavelength converting particles that convert incident light having a specific wavelength into a first wavelength to emit it and second wavelength converting particles that convert incident light into a second wavelength to emit it. In an exemplary embodiment, the light emitted from the light source 400 and incident on the wavelength conversion particles may be blue light, the first wavelength may be a green wavelength, and the second wavelength may be a red wavelength. For example, a blue wavelength may have a peak at 420 to 470 nanometers, a green wavelength may have a peak at 520 to 570 nanometers, and a red wavelength may have a peak at 620 to 670 nanometers. However, it is to be understood that the wavelengths of red, green and blue are not limited to the above numerical values, and encompass the entire range of wavelengths that can be considered in the art as red, green and blue.

In the above exemplary embodiment, blue light incident on the wavelength-converting layer 30 passes through the wavelength-converting layer 30, and a portion thereof is incident on the first wavelength-converting particles to be converted into a green wavelength and emitted. Another part of the light is incident on the second wavelength converting particles to be converted into a red wavelength and emitted. The other part of the light is incident on neither the first wavelength converting particle nor the second wavelength converting particle and may be emitted as it is. Accordingly, the light passing through the wavelength conversion layer 30 includes all of the blue wavelength light, the green wavelength light, and the red wavelength light. By appropriately adjusting the proportion of the outgoing light having different wavelengths, white light or light of another color can be emitted and displayed. The light converted in the wavelength conversion layer 30 is concentrated in a narrow range of specific wavelengths and has a sharp spectrum including a narrow half width. Therefore, the color gamut (color gamut) can be improved by filtering such spectrum of light with a color filter to reproduce the color.

Unlike the above exemplary embodiment, the incident light may be light of a short wavelength, such as ultraviolet light, and three kinds of wavelength conversion particles may be disposed in the wavelength conversion layer 30 for converting the incident light into blue, green, and red wavelengths, thereby emitting white light.

The wavelength conversion layer 30 may also include scattering particles. The scattering particles may be non-quantum dots that do not perform wavelength conversion. The scattering particles scatter incident light such that more incident light can be incident on the wavelength converting particles. Furthermore, the scattering particles can adjust the exit angle of light having different wavelengths. Specifically, when a part of incident light is incident on the wavelength converting particles and then the wavelength is converted and emitted, the emission direction has an arbitrary scattering property. If there are no scattering particles in the wavelength conversion layer 30, light having green and red wavelengths emitted after colliding with the wavelength conversion particles has a scattering property, but light having blue wavelengths emitted without colliding with the wavelength conversion particles does not have a scattering property. Therefore, the amount of exit light of blue/green/red wavelengths will become different depending on the exit angle. The scattering particles provide scattering properties to light of blue wavelength that does not collide with the wavelength converting particles in effect, so that the exit angles of light having different wavelengths can be regulated. TiO may be used₂、SiO₂Etc. as scattering particles.

The wavelength converting layer 30 may be thicker than the low refractive index layer 20. The thickness of the wavelength conversion layer 30 may be approximately in the range from 10 μm to 50 μm. In an exemplary embodiment, the thickness of the wavelength conversion layer 30 may be about 15 μm.

The wavelength conversion layer 30 may cover the upper surface 20a of the low refractive index layer 20 and may completely overlap with the low refractive index layer 20. The lower surface 30b of the wavelength conversion layer 30 may be in direct contact with the upper surface 20a of the low refractive index layer 20. In an exemplary embodiment, the side surfaces 30s of the wavelength conversion layer 30 may be aligned with the side surfaces 20s of the low refractive index layer 20, respectively. The side surface 30s of the wavelength conversion layer 30 may be positioned more inward than a boundary between the upper face 10a of the light guide plate 10 and each of the inclined faces 10r of the light guide plate 10.

The side surface 30s of the wavelength conversion layer 30 and the side surface 20s of the low refractive index layer 20 may not be perpendicular to the upper face 10a of the light guide plate 10, but may have a tilt angle less than 90 degrees. In some exemplary embodiments, the inclination angle of the side surface 30s of the wavelength conversion layer 30 may be smaller than the inclination angle of the side surface 20s of the low refractive index layer 20. When the wavelength conversion layer 30 is formed by slit coating or the like (which will be described later), the side surface 30s of the relatively thick wavelength conversion layer 30 may have a smaller inclination angle than the inclination angle of the side surface 20s of the low refractive index layer 20. However, it is to be understood that the inventive concept is not so limited. Depending on the formation method, the inclination angle of the side surface 30s of the wavelength conversion layer 30 may be substantially equal to or smaller than the inclination angle of the side surface 20s of the low refractive index layer 20. Further, the side surface 30s of the wavelength conversion layer 30 and the side surface 20s of the low refractive index layer 20 may not have an inclination angle smaller than 90 degrees, but may instead be perpendicular to the upper face 10a of the light guide plate 10.

The wavelength conversion layer 30 may be formed by coating or the like. For example, the wavelength conversion composition may be slit-coated on the light guide plate 10 on which the low refractive index layer 20 is formed, and then dried and cured, so that the wavelength conversion layer 30 may be formed. However, it is to be understood that the inventive concept is not so limited. Wavelength-converting layer 30 may be formed in a variety of other ways.

A passivation layer 40 may be disposed on the low refractive index layer 20 and the wavelength conversion layer 30. The passivation layer 40 serves to prevent the penetration of moisture and/or oxygen (hereinafter, referred to as "moisture/oxygen"). The passivation layer 40 may include an inorganic material. For example, the passivation layer 40 may include silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide, titanium oxide, tin oxide, cerium oxide, and silicon oxynitride or a metal thin film having light transmittance. In an exemplary embodiment, the passivation layer 40 may be made of silicon nitride.

The passivation layer 40 may completely cover the low refractive index layer 20 and the wavelength conversion layer 30 at least one side of the low refractive index layer 20 and the wavelength conversion layer 30. In an exemplary embodiment, for example, the passivation layer 40 may completely cover the low refractive index layer 20 and the wavelength conversion layer 30 on all sides.

The passivation layer 40 completely overlaps the wavelength conversion layer 30 and covers the upper surface 30a of the wavelength conversion layer 30. It may further extend outward to cover the side surface 30s of the wavelength conversion layer 30 and even the side surface 20s of the low refractive index layer 20. The passivation layer 40 may be in contact with the upper surface 30a and the side surface 30s of the wavelength conversion layer 30 and the side surface 20s of the low refractive index layer 20. The passivation layer 40 may extend to the upper face 10a of the light guide plate 10 exposed through the low refractive index layer 20 so that a portion of an edge of the passivation layer 40 may be in contact with the upper face 10a of the light guide plate 10. In an exemplary embodiment, the side surface 40s of the passivation layer 40 may be aligned with the side surface 10s of the light guide plate 10.

The thickness of the passivation layer 40 may be less than the thickness of the wavelength conversion layer 30, and may be similar to or less than the thickness of the low refractive index layer 20. The thickness of the passivation layer 40 may be in the range from 0.1 μm to 2 μm. If the thickness of the passivation layer 40 is greater than or equal to 0.1 μm, the passivation layer 40 may actually prevent the penetration of moisture/oxygen. If the thickness is greater than or equal to 0.3 μm, the passivation layer 40 may effectively prevent the penetration of moisture/oxygen. The passivation layer 40 having a thickness of less than or equal to 2 μm is advantageous in terms of reduction in size and increase in transmittance. In an exemplary embodiment, the thickness of the passivation layer 40 may be about 0.4 μm.

The wavelength converting layer 30, in particular the wavelength converting particles comprised therein, is susceptible to moisture/oxygen. When the wavelength conversion layer is employed, barrier films are stacked on the top and bottom surfaces of the wavelength conversion layer to prevent moisture/oxygen from penetrating into the wavelength conversion layer. However, according to this exemplary embodiment, the wavelength conversion layer 30 is directly provided without the blocking film, and thus, a sealing structure for protecting the wavelength conversion layer 30 is required. The sealing structure may be implemented by the passivation layer 40 and the light guide plate 10.

Moisture may penetrate into the wavelength conversion layer 30 through the upper surface 30a, the side surface 30s, and the lower surface 30b of the wavelength conversion layer 30. As described previously, the upper surface 30a and the side surface 30s of the wavelength conversion layer 30 are covered and protected by the passivation layer 40, and thus, the penetration of moisture/oxygen can be blocked or at least reduced (hereinafter referred to as "blocking/reducing").

The lower surface 30b of the wavelength conversion layer 30 is in contact with the upper surface 20a of the low refractive index layer 20. When the low refractive index layer 20 contains the voids VD or the organic material, moisture may move into the low refractive index layer 20, and thus, moisture/oxygen may permeate through the lower surface 30b of the wavelength conversion layer 30. However, according to this exemplary embodiment, the low refractive index layer 20 is also sealed, so that moisture/oxygen can be prevented from permeating through the lower surface 30b of the wavelength conversion layer 30.

Specifically, covering the side surface 20s of the low refractive index layer 20 by the passivation layer 40 enables blocking/reducing permeation of moisture/oxygen through the side surface 20s of the low refractive index layer 20. Even if the low refractive index layer 20 protrudes from the wavelength conversion layer 30 such that a portion thereof is exposed, the protruding portion may be covered and protected by the passivation layer 40, so that moisture/oxygen permeation through the protruding portion can be blocked/reduced. The lower surface 20b of the low refractive index layer 20 is in contact with the light guide plate 10. Similar to the passivation layer 40, when the light guide plate 10 is made of an inorganic material such as glass, it is possible to block/reduce the penetration of moisture/oxygen. Finally, the stack of the low refractive index layer 20 and the wavelength conversion layer 30 is surrounded and sealed by the passivation layer 40 and the light guide plate 10. Therefore, even if there is a path through which moisture/oxygen can move into the low refractive index layer 20, it is practically impossible for moisture/oxygen to enter into the low refractive index layer 20 due to the influence of the sealing structure. As a result, deterioration of the wavelength converting particles due to moisture/oxygen may be prevented or at least mitigated.

The passivation layer 40 may be formed by deposition or the like. For example, the passivation layer 40 may be formed by performing chemical vapor deposition on the light guide plate 10 on which the low refractive index layer 20 and the wavelength conversion layer 30 are sequentially formed. However, it is to be understood that the inventive concept is not so limited. The passivation layer 40 may be formed in a variety of other ways.

As described above, the optical member 100 may simultaneously perform the light guiding function and the wavelength converting function as an integrated single member. By implementing the optical member as an integrated single member, the process of assembling the display device can be made simpler. Further, in the optical member 100, the low refractive index layer 20 is disposed on the upper face 10a of the light guide plate 10, so that total reflection can be efficiently performed on the upper face 10a of the light guide plate 10. Further, the low refractive index layer 20 and the wavelength conversion layer 30 are sealed by the passivation layer 40 or the like, so that the wavelength conversion layer 30 can be prevented from being deteriorated.

The diffusion pattern 60 may be disposed on the lower face 10b of the light guide plate 10. The scattering pattern 60 serves to change the angle of light propagating in the light guide plate 10 by total reflection so that the light exits from the light guide plate 10.

In an exemplary embodiment, the light guide plate 10 itself may have the scattering pattern 60. For example, a recess groove formed in the lower face 10b of the light guide plate 10 may serve as the scattering pattern 60.

In another exemplary embodiment, the scattering pattern 60 may be implemented as a separate layer or pattern. For example, a pattern layer including a protrusion pattern and/or a recess groove pattern may be formed on the lower face 10b of the light guide plate 10, or a printed pattern may be formed on the lower face 10b of the light guide plate 10 to serve as the diffusion pattern 60.

The scattering pattern 60 may have different densities according to regions. For example, the scattering pattern 60 may have a lower density near the light incident surface 10s1 and may have a higher density near the opposite surface 10s3, where a larger amount of light propagates at the light incident surface 10s1 and a smaller amount of light propagates at the opposite surface 10s 3.

The reflective tape 50 may be disposed on at least one side surface 10s of the light guide plate 10. Fig. 1 and 2 show that the reflection tape 50 is disposed so as to cover the opposing face 10s3 opposite to the light incident face 10s 1. The reflection tape 50 may cover the facing surface 10s3 and the inclined surface 10r3 connected to the facing surface 10s3 of the light guide plate 10. In some exemplary embodiments, the reflection band 50 may also cover the side surface 20s of the low refractive index layer 20, the side surface 30s of the wavelength conversion layer 30, and the side surface 40s of the passivation layer 40, and the light guide plate 10.

The reflection band 50 may include a first folded portion 50a, a second folded portion 50b, and a side cover portion 50 s. The side cover portion 50s faces the side face 10s of the light guide plate 10. The first folding portion 50a extends from one end of the side cover portion 50s and is foldable along a first folding line FL1 to cover the first inclined surface 10r3a of the light guide plate 10. The second folding portion 50b extends from the other end of the side cover portion 50s and may be folded along a second folding line FL2 to cover the second inclined surface 10r3b of the light guide plate 10.

The first and second folded portions 50a and 50b of the reflection band 50 may be regions of the reflection band 50. The first and second folded portions 50a and 50b of the reflection band 50 may extend to the ends of the reflection band 50, respectively. The first and second folded portions 50a and 50b of the reflective tape 50 may be distinguished from the side cover portion 50s by fold lines FL1 and FL 2. In the following description, unless otherwise noted, the first folding line FL1 and the second folding line FL2 will be collectively referred to as a folding line FL.

As described above with reference to fig. 3A and 3B, when the inclined surface 10r is formed only on the upper or lower side of the light guide plate 10, the reflection band 50 may include only the first folding portion 50a or the second folding portion 50B.

For example, as shown in fig. 3A, when the inclined surface 10r is formed only between the upper surface 10a and the side surface 10s of the light guide plate 10, the reflection tape 50 may include the first folding portion 50a without including the second folding portion 50 b. That is, the side cover portion 50s of the reflection band 50 may extend to the boundary between the opposite face 10s3 and the lower face 10 b.

Further, as shown in fig. 3B, when the inclined surface 10r is formed only between the lower surface 10B and the side surface 10s of the light guide plate 10, the reflection tape 50 may include the second folding portion 50B without the first folding portion 50 a. That is, the side cover portion 50s of the reflection band 50 may extend to the boundary between the opposite face 10s3 and the upper face 10 a.

The reflection tape 50 is disposed on the side surface 10s of the light guide plate 10 to prevent light incident into the light guide plate 10 from leaking to the outside. Specifically, referring to fig. 1, light emitted from a light source 400 is incident into the light guide plate 10 through the light incident surface 10s1 of the light guide plate 10. Light incident into the light guide plate 10 may be guided by the light guide plate 10 and propagate to a side where the wavelength conversion layer 30 is disposed. However, some of the light may not propagate toward the wavelength conversion layer 30, but may instead leak out of the light guide plate 10. The incident light may particularly leak from the opposite face 10s3 of the light guide plate 10. The side cover portion 50s of the reflection band 50 may include a reflection surface for reflecting light, while each of the first and second folding portions 50a and 50b may include a light absorbing layer for absorbing light. Accordingly, light incident into the light guide plate 10 may be prevented from leaking by attaching the reflection tape 50 to the side surface 10s3 and the inclined surface 10r3 of the light guide plate 10.

The reflection band 50 includes first and second folding portions 50a and 50b to effectively block light from leaking through the first and second inclined surfaces 10r3a and 10r3b of the light guide plate 10. In addition, the first and second folded portions 50a and 50b of the reflection tape 50 may improve the adhesion of the reflection tape 50 attached to the opposite surface 10s3 of the light guide plate 10. If a portion of the contact surface between the light guide plate 10 and the reflection tape 50 is peeled off, incident light may leak through the portion. Therefore, by forming the first folding portion 50a and the second folding portion 50b, the reflection tape 50 can be attached to the opposite face 10s3 of the light guide plate 10 without any peeling of any part of the contact surface.

The structure of the reflection band 50 will be described in detail with reference to fig. 5 and 6.

Fig. 5 is a plan view of a reflection band according to an exemplary embodiment of the present invention. Fig. 6 is a sectional view taken along line X2-X2' of fig. 5.

Referring to fig. 5 and 6 in conjunction with fig. 1 and 2, as described above, the reflection band 50 may include the first folding portion 50a, the second folding portion 50b, and the side cover portion 50 s. The first folding portion 50a may be connected to one end of the side cover portion 50s, and the second folding portion 50b may be connected to the other end of the side cover portion 50 s. The portions may be separated by fold lines FL. The area of the first folded portion 50a may be equal to the area of the second folded portion 50 b. Further, the area of the first folding portion 50a and the area of the second folding portion 50b may be smaller than the area of the side cover portion 50 s. It should be understood that the area of each of the first folding portion 50a, the second folding portion 50b, and the side cover portion 50s is not limited thereto. The area of the first folded portion 50a may be larger than that of the second folded portion 50b, or conversely, the area of the second folded portion 50b may be larger than that of the first folded portion 50 a. In some exemplary embodiments, each of the first and second folding portions 50a and 50b may have an area greater than that of the side cover portion 50 s.

Further, the first and second folded portions 50a and 50b are attached along the first and second inclined faces 10r3a and 10r3b, respectively, and thus may conform to the shapes of the first and second inclined faces 10r3a and 10r3b, respectively. Fig. 5 is a plan view showing a part of the reflection band 50, and therefore, the shape of the reflection band 50 may not be rectangular. For example, the first and second inclined surfaces 10r3a and 10r3b may have a substantially trapezoidal shape, and thus, the shapes of the first and second folded portions 50a and 50b may also have a trapezoidal shape. Specifically, the first folding portion 50a may have a trapezoidal shape such that the length of the boundary between one side of the first folding portion 50a and the side cover portion 50s may be greater than the length of the other side of the first folding portion 50 a.

The reflective tape 50 may include a base layer 51, a reflective layer 53, a light absorbing layer 55, a protective layer 57, and an adhesive layer 59.

The base layer 51 may be a support member for supporting the layers of the reflective tape 50. The dimensions of the substrate layer 51 may be substantially equal to the dimensions of the reflective strips 50. The base layer 51 may be in the form of a thin film and the upper and lower surfaces of the base layer 51 are parallel to each other. In an exemplary embodiment, the base layer 51 may be a polyethylene terephthalate (PET) film. Note that, herein, the material of the base layer 51 is not particularly limited as long as it is flexible and can prevent the penetration of moisture/oxygen.

The reflective layer 53 may be disposed on the base layer 51. The reflective layer 53 may be formed to cover the entire surface of the base layer 51. That is, the reflective layer 53 may be formed on the entire surface of the reflective band 50 including the first and second folded portions 50a and 50b and the side cover portion 50s of the reflective band 50. The reflective layer 53 may be formed such that the upper surface of the reflective layer 53 is parallel to the upper surface of the base layer 51. The reflective layer 53 may have a property of reflecting all light incident on the reflective tape 50. The reflective layer 53 may reflect the entire visible ray regardless of the wavelength band of the light. Herein, the material of the reflective layer 53 is not particularly limited as long as it can reflect light in all wavelength bands. For example, the reflective layer 53 may include a light reflective material having a high reflectivity, such as a metal. In an exemplary embodiment, the reflective layer 53 may include silver (Ag). In another exemplary embodiment, the reflective layer 53 may have a structure in which a plurality of layers having different refractive indexes are stacked on one another, such as a reflective polarizing film. The reflective layer 53 may be deposited or coated directly on the upper surface of the base layer 51. As another example, it may be formed by attaching a separate member including the reflective layer 53.

The light absorbing layer 55 may be disposed on the reflective layer 53. Fig. 6 shows the light absorbing layer 55 formed in the first and second folded portions 50a and 50b of the reflection band 50. The reflection band 50 may be divided into an area where the light absorbing layer 55 is formed and other areas that do not overlap with the light absorbing layer 55. In an exemplary embodiment, the region where the light absorbing layer 55 is formed may be the first and second folded portions 50a and 50b, and the region not overlapping with the light absorbing layer 55 may be the side cover portion 50 s. The region where the light absorbing layer 55 is formed may absorb the incident light of the entire wavelength band, and the region of the reflective layer 53 not overlapping with the light absorbing layer 55 may reflect the incident light of the entire wavelength band. The reflection tape 50 absorbs the leaked light through the light absorbing layer 55 disposed in the first and second folding portions 50a and 50b, thereby preventing the user from recognizing the light leakage at the edge portion of the display apparatus.

In an exemplary embodiment, the light absorbing layer 55 may be a black printed layer absorbing all of the visible light wavelength band. Further, the light absorbing layer 55 may include a light absorbing material. Herein, the light absorbing material is not particularly limited as long as it is a material that absorbs light. The light absorbing layer 55 may include a material that absorbs light, such as a black pigment or dye. The light absorbing layer 55 may be coated directly on the reflective layer 53 or may be attached on the reflective layer 53 by a separate adhesive layer.

In an exemplary embodiment, as shown in fig. 6, the light absorbing layer 55 may be disposed in the regions of the first and second folded portions 50a and 50b, not in the side cover portion 50 s. That is, the area of the light absorbing layer 55 may be equal to the area of each of the first and second folded portions 50a and 50b when viewed from the top. However, the arrangement of the light absorbing layer 55 is not limited thereto. In some exemplary embodiments, the light absorbing layer 55 may be larger or smaller than the first and second folded portions 50a and 50 b. Further, the light absorbing layer 55 may be disposed on the entire surface of each of the first and second folded portions 50a and 50b, or in some exemplary embodiments, the light absorbing layer 55 may be disposed in the form of a light absorption pattern.

As described above, the side cover portion 50s of the reflection tape 50 includes the reflection layer 53 so that it can reflect all incident light directed to the opposite face 10s3 of the light guide plate 10. In addition, the first and second folded portions 50a and 50b of the reflection band 50 include the light absorbing layer 55 so that they can absorb all incident light directed toward the first and second inclined surfaces 10r3a and 10r3b of the light guide plate 10.

Fig. 7 to 9 are plan views of reflection bands according to exemplary embodiments.

Referring to fig. 7 and 8, when viewed from the top, the area of the light absorbing layer may be different from the area of each of the first and second folded portions.

For the first folded portion 50a _1 shown in fig. 7, the width Wr of the first folded portion 50a _1 may be a distance from one end of the reflective tape 50_1 to the first folding line FL 1. That is, in the reflection band 50_1 according to the exemplary embodiment shown in fig. 7, the light absorbing layer 55_1 may have a width Wt _1 greater than a width Wr of the first folded portion 50a _ 1. In other words, the side cover portion 50s _1 may include at least a portion of the light absorbing layer 55_ 1. However, it should be noted that even when the width Wt _1 of the light absorbing layer 55_1 is larger than the width Wr of the first folded portion 50a _1 as described above, at least a part of the side cover portion 50s _1 may not overlap with the light absorbing layer 55_1, and the reflective layer 53_1 may be exposed.

When the width Wt _1 of the light absorbing layer 55_1 is greater than the widths Wr of the first folded portion 50a _1 and the second folded portion 50b _1, the light absorbing layer 55_1 can reliably cover the boundary between the first inclined surface 10r3a and the opposing surface 10s3 and the boundary between the second inclined surface 10r3b and the opposing surface 10s 3. As a result, light leakage that may occur at the boundary can be effectively prevented.

The exemplary embodiment shown in fig. 8 differs from the exemplary embodiment of fig. 7 in that: the light absorbing layer 55_2 has a width Wt _2 smaller than a width Wr of the first folded portion 50a _ 2. When the width Wt _2 of the light absorbing layer 55_2 is less than the width Wr of the first folded portion 50a _2, at least a portion of the first folded portion 50a _2 does not overlap with the light absorbing layer 55_2, so that the reflective layer 53_2 may be exposed.

Such an exposed portion may be a tolerance area for preventing the light absorbing layer 55_2 from overlapping the opposite face 10s3 of the light guide plate 10 due to an error during the process of attaching the reflection tape 50_ 2. In other words, since the light absorbing layer 55_2 does not overlap the opposing face 10s3, the reflection tape 50_2 can completely reflect light incident on the opposing face 10s3 without absorbing it. As a result, light extraction efficiency can be improved.

Further, the light absorbing layer may have various shapes. Referring to fig. 9, the light absorbing layer 55_3 is formed in a pattern of two rows of dots. Note, however, that the shape of the light absorbing layer 55_3 is not limited thereto. It may have a polygonal pattern or an irregular pattern. In addition, the light absorbing layer 55_3 may be formed in two or more rows. That is, the light absorbing layer 55_3 may include a plurality of light absorbing patterns, and the light absorbing patterns may be spaced apart from each other.

Referring back to fig. 5 and 6, a protective layer 57 may be disposed on the light absorbing layer 55.

A protective layer 57 may be disposed on the reflective layer 53 and the light absorbing layer 55 to protect the reflective layer 53 and the light absorbing layer 55. In addition, the protective layer 57 may be disposed on the entire surfaces of the reflective layer 53 and the light absorbing layer 55. That is, the area of the protective layer 57 may be equal to the area of the reflection band 50. Herein, the material of the protective layer 57 is not particularly limited as long as it is flexible, can block moisture/oxygen permeation, and can transmit light. In some exemplary embodiments, the protective layer 57 may be removed. That is, the adhesive layer 59 may be directly disposed on the reflective layer 53 and the light absorbing layer 55 without the protective layer 57.

An adhesive layer 59 may be disposed on the protective layer 57. When the reflective tape 50 is attached to the light guide plate 10, the adhesive layer 59 may be in contact with the light guide plate 10. That is, one surface of the adhesive layer 59 may be in contact with the opposite surface 10s3 and the inclined surface 10r3 of the light guide plate 10, and the other surface of the adhesive layer 59 may be in contact with the protective layer 57 of the reflective tape 50. In some exemplary embodiments, when the protective layer 57 is removed, the other surface of the adhesive layer 59 may be directly disposed on the reflective layer 53 and the light absorbing layer 55. Further, in another exemplary embodiment, the adhesive layer 59 may be in contact with the base layer 51 and disposed on the base layer 51. For example, the adhesive layer 59 may include, for example, a transparent adhesive material such as an Optically Clear Resin (OCR) or an Optically Clear Adhesive (OCA).

Fig. 10 and 11 are views showing a modification of the structure shown in fig. 6. The structure shown in fig. 10 and 11 is substantially the same as that of fig. 6 except that the layers are disposed in different orders and at different positions, and therefore, any redundant description will be omitted.

Referring to fig. 10, the reflection band 50_4 may include a base layer 51, a reflection layer 53_4 and a light absorption layer 55_4 disposed on the base layer 51, and a protection layer 57_4 covering the reflection layer 53_4 and the light absorption layer 55_ 4.

Unlike the exemplary embodiment of fig. 6, the reflective layer 53_4 is provided only in the side cover portion 50s, and the light absorbing layer 55_4 is provided in the first and second folded portions 50a and 50 b.

The reflective layer 53_4 may be disposed on the base layer 51. Further, the reflective layer 53_4 may overlap with the side cover portion 50s, and may not overlap with the first and second folding portions 50a and 50 b. That is, the first and second folding portions 50a and 50b may not include the reflective layer 53_ 4. The light absorbing layer 55_4 may be directly disposed on the base layer 51, and may overlap the first and second folded portions 50a and 50 b.

The protective layer 57_4 may be disposed on the reflective layer 53_4 and the light absorbing layer 55_ 4. When the height of the reflective layer 53_4 is substantially equal to the height of the light absorbing layer 55_4, the protective layer 57_4 disposed on the reflective layer 53_4 and the light absorbing layer 55_4 may have a uniform thickness. That is, the upper and lower surfaces of the protective layer 57_4 may be arranged parallel to each other.

When the reflective layer 53_4 and the light absorbing layer 55_4 are disposed on the same layer, the manufacturing cost of the reflective tape 50_4 can be reduced. Specifically, when the reflective layer 53_4 overlaps the light absorbing layer 55_4 as in the exemplary embodiment of fig. 6, the overlapping area (e.g., the folded portion) absorbs the entire light, and thus the reflective layer 53_4 may not be required. That is, by removing the reflective layer 53_4 from the overlapping area, the manufacturing cost can be reduced. Further, since the reflective layer 53_4 and the light absorbing layer 55_4 are provided on the same layer, the reflective tape 50_4 can be provided thinner overall.

Referring to fig. 11, the reflection tape 50_5 may include a base layer 51, a light absorbing layer 55_5 disposed on the base layer 51, a reflection layer 53_5 disposed on the base layer 51 and the light absorbing layer 55_5, a protection layer 57_5 covering the reflection layer 53_5, and an adhesive layer 59_5 disposed under the base layer 51.

Unlike the exemplary embodiment of fig. 6, the light absorbing layer 55_5 is disposed between the base layer 51 and the reflective layer 53_ 5.

The light absorbing layer 55_5 may be directly disposed on the base layer 51, and may overlap the first and second folded portions 50a and 50 b.

The reflective layer 53_5 may be entirely disposed on the base layer 51 on which the light absorbing layer 55_5 is disposed. Although the upper surface of the reflective layer 53_5 is illustrated as being flat in fig. 11, in another exemplary embodiment, the reflective layer 53_5 may have a uniform thickness along the surfaces of the base layer 51 and the light absorbing layer 55_ 5.

The protective layer 57_5 may be disposed on the reflective layer 53_ 5. Specifically, the reflective layer 53_5 may be disposed between the protective layer 57_5 and the light absorbing layer 55_5, and the protective layer 57_5 may be spaced apart from the light absorbing layer 55_ 5. The protective layer 57_5 may have a uniform thickness along the surface of the reflective layer 53_ 5.

Adhesive layer 59_5 may be disposed below base layer 51. That is, the light absorbing layer 55_5 may be disposed on the upper surface of the base layer 51, and the adhesive layer 59_5 may be disposed on the lower surface of the base layer 51. As described above, the adhesive layer 59_5 may be a layer containing an adhesive material and attached to the light guide plate 10.

Since the adhesive layer 59_5 is disposed on the lower surface of the base layer 51 unlike the above-described exemplary embodiment, when the coupling force between the adhesive layer 59_5 and the base layer 51 is greater than the coupling force between the adhesive layer 59_5 and the protective layer 57_5, the coupling force between the light guide plate 10 and the reflective tape 50_5 may be enhanced.

Fig. 12 is a sectional view of an optical member according to another exemplary embodiment of the present invention. Fig. 13 is a sectional view of an optical member according to still another exemplary embodiment of the present invention. Fig. 14 is a plan view of the reflection band of fig. 13. FIG. 15 is a cross-sectional view of the reflective tape taken along line X3-X3' of FIG. 14.

Referring to fig. 12, the optical member 100_6 includes a stack structure 11_6 and a reflection band 50_6 covering a side surface of the stack structure 11_ 6.

The stack structure 11_6 may include an inclined surface 11_6 r. The inclined surface 11_6r of the stack structure 11_6 may include the inclined surface 10r3 of the light guide plate 10 and at least a portion of the side surface 40s of the passivation layer 40. The side surface 40s of the passivation layer 40 may be formed by cutting together when the inclined surface 10r3 of the light guide plate 10 is formed.

The reflection band 50_6 may be disposed on the side surface of the stack structure 11_6 and the inclined surface 11_6 r. The side of the stack structure 11_6 may be the same as the side 10s3 of the light guide plate 10. The reflection band 50_6 disposed on the inclined surface 11_6r may at least partially contact the side surface 40s of the passivation layer 40.

When the reflection band 50_6 is in contact with the side surface 40s of the passivation layer 40, the first folding portion 50a of the reflection band 50_6 covers the contact portion between the light guide plate 10 and the passivation layer 40, so that oxidation of the wavelength conversion material, which may occur on the side surface 30s of the wavelength conversion layer 30, can be more effectively prevented.

Referring to fig. 13 to 15, the optical member 100_7 may include a stack structure 11_7 and a reflective tape 50_7 attached to a side surface of the stack structure 11_ 7.

The exemplary embodiment shown in fig. 13 differs from the exemplary embodiment shown in fig. 12 in that: the reflection band 50_7 further includes a third folded portion 50c and a fourth folded portion 50 d.

The third folded portion 50c and the fourth folded portion 50d may be regions of the reflection band 50_ 7. That is, the third folded portion 50c of the reflection band 50_7 may extend from one end of the first folded portion 50a, and the fourth folded portion 50d may extend from one end of the second folded portion 50 b. The third folded portion 50c and the first folded portion 50a may be distinguished by a third fold line FL3, and the fourth folded portion 50d and the second folded portion 50b may be distinguished by a fourth fold line FL 4.

In the first and second folded portions 50a and 50b, the reflection band 50_7 may include a base layer 51_7, a reflection layer 53_7 disposed on the base layer 51_7, and a light absorption layer 55_7 disposed on the reflection layer 53_ 7.

The reflective layer 53_7 may be disposed to overlap the entire area of the reflective tape 50_ 7. That is, it may be a layer formed on the entire surface of the reflection band 50_ 7. The light absorbing layer 55_7 may not overlap the third and fourth folded portions 50c and 50d of the reflection band 50_ 7. In other words, the third and fourth folded portions 50c and 50d may overlap the reflective layer 53_7 and not the light absorbent layer 55_ 7. That is, the third folded portion 50c and the fourth folded portion 50d may reflect light.

The folding line FL may form a position where the ends of the folded portions 50a, 50b, 50c, and 50d of the reflection band 50_7 intersect. When the inclined surface 11_7r of the stacked structure 11_7 is formed in a plane, the reflective tape 50_7 may include four folding lines FL1, FL2, FL3, and FL4 in total. In the following description, the first folding line FL1_7, the second folding line FL2_7, the third folding line FL3, and the fourth folding line FL4 are collectively referred to as a folding line FL.

The reflective tape 50_7 may be attached along the side surface of the stacked structure 11_7 and the inclined surface 11_7r so that any portion of the contact portion between the stacked structure 11_7 and the reflective tape 50_7 is not peeled off by the folding line FL. The side of the stack structure 11_7 may be the same as the side 10s3 of the light guide plate 10.

Since the inclined surface 11_7r of the stack structure 11_7 has an uneven surface, a portion of the reflective tape 50_7 may be peeled off. Incident light may leak through such a portion. However, according to an exemplary embodiment of the present invention, when the reflection band 50_7 includes the third and fourth folded portions 50c and 50d, light leakage, which may occur when a portion of the reflection band 50_7 is peeled, may be prevented.

Fig. 16 is a perspective view of an optical member and a light source according to an exemplary embodiment of the present invention. Fig. 17 is a sectional view of the optical member taken along line X4-X4' of fig. 16.

According to the exemplary embodiments shown in fig. 16 and 17, a plurality of reflection tapes may cover a plurality of side surfaces of the light guide plate. Other elements may be the same as those of the exemplary embodiment described above with reference to fig. 1 and 2, except for the configuration of the reflection band. Therefore, any redundant description will be omitted.

Specifically, referring to fig. 16 and 17, the optical member 100_8 may include a light guide plate 10 and first, second, and third reflection bands 50_8A, 50_8B, and 50_8C covering side surfaces 10s of the light guide plate 10, respectively. The first reflection tape 50_8A may cover the opposite surface 10s3 of the light guide plate 10. The second and third reflection bands 50_8B and 50_8C may cover the side faces 10s2 and 10s4 and the inclined faces 10r2 (e.g., 10r2a and 10r2B) and 10r4 (e.g., 10r4a and 10r4B), respectively, connected to the opposite face 10s3 of the light guide plate 10. That is, the first, second, and third reflection tapes 50_8A, 50_8B, and 50_8C may cover the side surfaces 10s2, 10s3, and 10s4, in addition to the light incident surface 10s 1. The first reflection band 50_8A is substantially the same as those described above with reference to the above embodiments. Therefore, a detailed description thereof will be omitted.

The second reflective band 50_8B can include a second side cover portion 50s _8B, a third folded portion 50a _8B extending from one end of the second side cover portion 50s _8B, and a fourth folded portion 50B _8B extending from the other end of the second side cover portion 50s _ 8B.

The third reflection band 50_8C may include a third side cover portion 50s _8C, a fifth folded portion 50a _8C extending from one end of the third side cover portion 50s _8C, and a sixth folded portion 50b _8C extending from the other end of the third side cover portion 50s _ 8C.

The first, second, and third reflection bands 50_8A, 50_8B, and 50_8C may not overlap each other at the boundaries of the sides 10s2, 10s3, and 10s 4. However, in some exemplary embodiments, the first, second, and third reflection bands 50_8A, 50_8B, and 50_8C may at least partially overlap one another.

Light incident through the light incident surface 10s1 may leak through the opposing surface 10s3 and the side surfaces 10s2 and 10s4 connected to the opposing surface 10s 3. Accordingly, the incident light may be prevented from leaking by the second and third reflection tapes 50_8B and 50_8C further covering the right and left side faces 10s2 and 10s4 of the light guide plate 10.

Although the light guide plate 10 including three side surfaces in addition to the light incident surface 10s1 is illustrated in fig. 16 and 17, the inventive concept is not limited thereto. For example, the reflection tape 50_8 may also cover only the right side face 10s2 or the left side face 10s4 of the light guide plate 10. In summary, the reflection tape may cover at least two side surfaces among a plurality of side surfaces of the light guide plate in addition to the light incident surface, wherein the light guide plate is a polygonal light guide plate having three or more side surfaces.

Fig. 18 is a sectional view of a display apparatus according to an exemplary embodiment of the present invention. The display apparatus 1000 shown in fig. 18 may include the optical member 100 described above with reference to fig. 1 and 2. The optical member 100 provided in the display apparatus 1000 is merely an example, and the present disclosure is not limited thereto. The optical member according to any of the above-described exemplary embodiments may be employed.

Referring to fig. 18, the display apparatus 1000 includes a light source 400, an optical member 100 disposed on an emission path of the light source 400, and a display panel 300 disposed over the optical member 100.

The light source 400 is disposed on one side of the optical member 100. The light source 400 may be disposed adjacent to the light incident surface 10s1 of the light guide plate 10 of the optical member 100. The light source 400 may include a point light source or a line light source. As previously described, the point light sources may be Light Emitting Diode (LED) light sources 410. A plurality of LED light sources 410 may be mounted on a printed circuit board 420. The LED light source 410 may emit blue light.

In an exemplary embodiment, as shown in fig. 18, the LED light source 410 may be a top-emitting LED that emits light upward. In such a case, the printed circuit board 420 may be disposed on the sidewall 520 of the case 500. Although not shown in the drawings, in another exemplary embodiment, the LED light source 410 may be a side-emitting LED that emits light through a side surface. In such a case, the printed circuit board 420 may be disposed on the bottom 510 of the case 500.

Blue light emitted from the LED light source 410 is incident on the light guide plate 10 of the optical member 100. The light guide plate 10 of the optical member 100 guides light and outputs the light through an upper face 10a or a lower face 10b of the light guide plate 10. The wavelength conversion layer 30 of the optical member 100 converts a part of light of a blue wavelength incident from the light guide plate 10 into other wavelengths, such as a green wavelength and a red wavelength. The converted green and red wavelengths of light, along with the blue wavelength of unconverted light, exit upward toward the display panel 300.

The display apparatus 1000 may further include a reflective member 70 disposed under the optical member 100. The reflective member 70 may include a reflective film or a reflective coating layer. The reflection member 70 reflects the light emitted through the lower surface 11b of the light guide plate 10 of the optical member 100 back toward the inside of the light guide plate 10.

The display panel 300 is disposed over the optical member 100. The display panel 300 receives light from the optical member 100 to display an image. Examples of such a light receiving display panel displaying an image by receiving light may include a liquid crystal display panel, an electrophoretic panel, and the like. Although the liquid crystal display panel is described as an example in the following description, any of various other light receiving display panels may be employed.

The display panel 300 may include a first substrate 310, a second substrate 320 facing the first substrate 310, and a liquid crystal layer (not shown) disposed between the first substrate 310 and the second substrate 320. The first substrate 310 and the second substrate 320 overlap each other. In an exemplary embodiment, one of the substrates may be larger than the other substrates so that it may protrude further outward. In the drawing, the second substrate 320 located above the first substrate 310 is larger than the first substrate 310 and may protrude from a side where the light source 400 is disposed. The protruding portion of the second substrate 320 may provide a space for mounting a driving chip or an external circuit board. Unlike the illustrated example, the first substrate 310 located under the second substrate 320 may be larger than the second substrate 320 and protrude outward. In the display panel 300, the first substrate 310 and the second substrate 320 overlapped with each other may be substantially aligned with the side face 10s of the light guide plate 10 of the optical member 100 except for the protruding portion.

The optical member 100 may be coupled with the display panel 300 by the inter-module coupling member 610. The inter-module coupling member 610 may have a rectangular frame shape when viewed from the top. The inter-module coupling member 610 may be located at an edge of each of the display panel 300 and the optical member 100.

In an exemplary embodiment, the bottom surface of the inter-module coupling member 610 is disposed on the upper surface 40a of the passivation layer 40 of the optical member 100. The bottom surface of the inter-module coupling member 610 may be disposed on the passivation layer 40 such that it overlaps only the upper surface 30a of the wavelength conversion layer 30 and does not overlap the side surface 30 s.

The inter-module coupling member 610 may include a polymer resin, an adhesive tape, a detachable tape, and the like.

In some exemplary embodiments, the inter-module coupling member 610 may serve as a pattern for blocking light transmission. For example, the inter-module coupling member 610 may include a light absorbing material such as black pigment and dye, or may include a reflective material for blocking light transmission.

The display device 1000 may further include a housing 500. The housing 500 has an open face and includes a bottom 510 and a sidewall 520 connected to the bottom 510. The assembly of the light source 400, the optical member 100 and the display panel 300, and the reflection member 70 may be accommodated in a space defined by the bottom 510 and the sidewall 520. The light source 400, the reflection member 70, and the assembly of the optical member 100 and the display panel 300 may be disposed on the bottom 510 of the case 500. The height of the sidewall 520 of the case 500 may be substantially equal to the height of the assembly of the optical member 100 and the display panel 300 placed inside the case 500. The display panel 300 is disposed adjacent to the upper end of the sidewall 520 of the case 500, and they may be coupled to each other by the case coupling member 620. The case coupling member 620 may have a rectangular frame shape when viewed from the top. The housing coupling member 620 may include a polymer resin, an adhesive tape, a detachable tape, and the like.

The display device 1000 may further include at least one optical film 200. One or more optical films 200 may be accommodated in a space surrounded by the inter-module coupling member 610 between the optical member 100 and the display panel 300. The side surfaces of one or more optical films 200 may be attached to the inner side surfaces of the inter-module coupling members 610 in contact therewith. Although the optical film 200 and the optical member 100 are spaced apart from each other and the optical film 200 and the display panel 300 are spaced apart from each other, they are not necessarily spaced apart from each other.

The optical film 200 may be a prism film, a diffusion film, a microlens film, an uneven film (lenticular film), a polarizing film, a reflective polarizing film, a retardation film, or the like. The display device 1000 may also include a plurality of optical films 200 of the same type or different types. When a plurality of optical films 200 are employed, each of the optical films 200 may overlap each other, and a side surface of each of the optical films 200 may be in contact with an inner side surface of the inter-module coupling member 610 and attached to the inner side surface of the inter-module coupling member 610. The optical films 200 may be spaced apart from each other and an air layer may be disposed therebetween.

According to the exemplary embodiments of the present invention, the optical member may effectively prevent light incident into the light guide plate from leaking through the opposite surface, rather than exiting toward the wavelength conversion layer.

Although certain exemplary embodiments have been described herein, other embodiments and modifications will be apparent from this description. Accordingly, the inventive concept is not limited to such embodiments, but lies in the broader scope of the appended claims and various obvious modifications and equivalent arrangements as would be apparent to those skilled in the art.

Claims (17)

1. An optical member comprising:

a light guide plate including an upper surface, a first side surface, and a first inclined surface disposed between the upper surface and the first side surface;

a wavelength conversion layer disposed on the upper face of the light guide plate; and

a first reflection band including a first side portion covering the first side face and a first folding portion extending from one end of the first side portion and covering the first inclined face,

wherein the content of the first and second substances,

a side surface of the wavelength conversion layer is disposed more inward than a boundary between the upper face and the first inclined face; and

the first side portion includes a reflective layer and the first fold portion includes a light absorbing layer.

2. The optical member according to claim 1,

the light guide plate includes a lower face and a second inclined face disposed between the lower face and the first side face; and

the first reflection band includes a second folded portion extending from the other end of the first side portion and covering the second inclined surface.

3. The optical member of claim 2, wherein the first side portion further comprises a base layer, and the reflective layer is disposed on a surface of the base layer facing the first side.

4. The optical member of claim 3, wherein the first and second folded portions further comprise the base layer, and the light absorbing layer is disposed on the surface of the base layer.

5. The optical member of claim 4, wherein the first and second folded portions further comprise a reflective layer disposed between the base layer and the light absorbing layer.

6. The optical member of claim 5, wherein at least a portion of the first side portion includes the light absorbing layer.

7. The optical member according to claim 5,

the light absorbing layer includes a plurality of light absorbing patterns, an

The light absorbing patterns are spaced apart from each other.

8. The optical member of claim 4, wherein the first and second folded portions further comprise the reflective layer, the light absorbing layer being disposed between the base layer and the reflective layer.

9. The optical member according to claim 1,

the light guide plate includes a second side surface adjacent to the first side surface and a third inclined surface disposed between the upper surface and the second side surface; and

the optical member further includes a second reflective tape including:

a second side portion covering the second side; and

a third folded portion extending from one end of the second side portion and covering the third inclined face.

10. The optical member according to claim 9,

the light guide plate includes a lower face opposing the upper face and a fourth inclined face disposed between the lower face and the second side face; and

the second reflection band includes a fourth folded portion extending from the other end of the second side portion and covering the fourth inclined face.

11. The optical member according to claim 9,

the light guide plate includes a third side surface opposite to the second side surface and a fifth inclined surface disposed between the upper surface and the third side surface; and

the optical member further includes a third reflective band, the third reflective band including:

a third side portion covering the third side; and

a fifth folding portion extending from one end of the third side portion and covering the fifth inclined surface.

12. The optical member according to claim 11,

the light guide plate includes a lower face opposite to the upper face and a sixth inclined face disposed between the lower face and the third side face; and

the third reflection band includes a sixth folding portion extending from the other end of the third side portion and covering the sixth inclined surface.

13. The optical member of claim 11, wherein the length of the first reflection band is greater than the length of each of the second reflection band and the third reflection band.

14. The optical member as claimed in claim 1, wherein a length of a boundary between one end of the first folding portion and the one end of the first side portion is greater than a length of the other end of the first folding portion.

15. A display device, comprising:

a light guide plate including an upper surface, a first side surface, a first inclined surface disposed between the upper surface and the first side surface, and a second side surface opposite to the first side surface;

a wavelength conversion layer disposed on the upper face of the light guide plate;

a light source disposed to face the second side of the light guide plate;

a reflection band including a first side portion covering the first side surface and a first folding portion extending from one end of the first side portion and covering the first inclined surface; and

a display panel disposed above the light guide plate,

wherein the content of the first and second substances,

a side surface of the wavelength conversion layer is disposed more inward than a boundary between the upper face and the first inclined face; and

the first side portion includes a reflective layer and the first fold portion includes a light absorbing layer.

16. The display device of claim 15,

the light guide plate comprises a lower surface and a second inclined surface arranged between the lower surface and the first side surface; and

the reflection band includes a second folded portion extending from the other end of the first side portion and covering the second inclined surface.

17. The display device of claim 16,

the light source emits blue light; and

the wavelength conversion layer includes a first wavelength conversion material for converting the blue light into red light and a second wavelength conversion material for converting the blue light into green light.

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