Patent Description:
A liquid crystal display generally receives light from a backlight assembly and displays an image. Some backlight assemblies include a light source and a light guide plate. The light guide plate may receive light from the light source, and guide the light toward a display panel. In some products, the light source provides white light, and the white light is filtered by a color filter of the display panel to realize color.

Recently, research has been conducted on application of a wavelength conversion film to improve image quality, such as color reproducibility of a liquid crystal display. Generally, a blue light source is used as a light source, and a wavelength conversion film is disposed on a light guide plate to convert blue light into white light. The wavelength conversion film typically includes wavelength conversion particles. Since the wavelength conversion particles are generally vulnerable to moisture, they are protected with a barrier film. However, the barrier film is expensive and may increase the overall thickness of a device. Further, since the wavelength conversion film should be laminated on the light guide plate, a complicated assembling process may be required.

<CIT> discloses a gas barrier film, a wavelength conversion member, and a backlight unit that have both gas barrier properties and optical properties.

<CIT> discloses an optical member including a wavelength conversion layer to convert a wavelength of an incident light; an upper anti-reflective layer of at least two layers disposed on a first surface of the wavelength conversion layer; and a lower anti-reflective layer of at least two layers disposed under a second surface of the wavelength conversion layer opposite to the first surface.

<CIT> discloses a liquid crystal display device having high transmittance and a high color reproduction region, which includes a backlight unit including a light conversion member; and a liquid crystal cell and in which the light conversion member includes a light conversion layer containing a fluorescent material and an optical film arranged on both surfaces of the light conversion layer, the optical film includes an optical thin film forming an air interface, and a layer directly adjacent to the optical thin film, the liquid crystal display device satisfies n(<NUM>)<nu(<NUM>), n(<NUM>)×d is in a specific range, transmittance of a laminated body of the optical thin film and the layer directly adjacent to the optical thin film is in a specific range, and the backlight unit emits blue light, green light, and red light.

<CIT> discloses a liquid crystal display device, which includes a backlight unit including a light conversion member; and a liquid crystal cell and in which the light conversion member includes a light conversion layer containing a fluorescent material and an optical film arranged on both surfaces of the light conversion layer, the optical film includes an optical thin film forming an air interface, and a layer directly adjacent to the optical thin film, the liquid crystal display device satisfies n(<NUM>).

<CIT> discloses devices, apparatuses and methods of providing an optical filter with quantum dot films for converting a first wavelength of light to a second wavelength of light. The optical filter includes a plurality of high refractive index layers and a plurality of low refractive index layers alternatingly disposed between the high refractive index layers. Quantum dots are dispersed in either the high refractive index layers or the low refractive index layers. In some implementations, the quantum dots are capable of absorbing blue light and emitting green light. Thus, the optical filter can be part of a red-green-blue lighting device that includes a first blue LED optically coupled with the optical filter to produce green light, a red LED and a second blue LED.

An optical member having a laminated structure and a display device including the same according to exemplary implementations of the invention are capable of providing improved light transmission efficiency.

According to an aspect of the invention, there is provided an optical member as set out in claim <NUM>. Preferred features of this aspect are set out in claims <NUM> to <NUM>.

According to an aspect of the invention, there is provided a display as set out in claim <NUM>.

<FIG> is a perspective view of an optical member <NUM> and a light source <NUM> according to an exemplary embodiment. <FIG> is a cross-sectional view taken along line II-II' of <FIG>.

Referring to <FIG> and <FIG>, the optical member <NUM> may include a light guide plate <NUM>, a wavelength conversion underlying layer <NUM> disposed on the light guide plate <NUM>, a wavelength conversion layer <NUM> disposed on the wavelength conversion underlying layer <NUM>, and a wavelength conversion overlying layer <NUM> disposed on the wavelength conversion layer <NUM>. The wavelength conversion underlying layer <NUM> may include a low refractive underlying layer <NUM>, a low refractive layer <NUM> disposed on the low refractive underlying layer <NUM>, and a low refractive overlying layer <NUM> disposed on the low refractive layer <NUM>.

The light guide plate <NUM> may guide the path of light. The light guide plate <NUM> may generally have a substantially polygonal column shape. The planar shape of the light guide plate <NUM> may be substantially rectangular, but embodiments of the inventive concept are not limited thereto. In an exemplary embodiment, the light guide plate <NUM> may have a substantially hexagonal column shape having a rectangular planar shape, and may include an upper surface 10a, a lower surface 10b, and four side surfaces 10S1, 10S2, 10S3, and 10S4. Hereinafter, the four side surfaces of the light guide plate <NUM> will be indicated as 10S1, 10S2, 10S3, and 10S4, respectively, and one of the four sides will be generally indicated as <NUM>.

In an exemplary embodiment, each of the upper surface 10a and the lower surface 10b of the light guide plate <NUM> may be disposed on respective plane. More particularly, the plane on which the upper surface 10a is disposed may be substantially parallel to the plane on which the lower surface 10b is disposed, such that the overall thickness of the light guide plate <NUM> is uniform. However, the upper surface 10a or the lower surface 10b may be formed of a plurality of planes, or the plane on which the upper surface 10a is disposed may intersect the plane on which the lower surface 10b is disposed. For example, the light guide plate <NUM> may become thinner from one side surface (e.g., a light incidence surface) toward another side surface (e.g., a counter surface) facing the one side surface, like a wedge-type light guide plate. Alternatively, the lower surface 10b may slope upward from one side surface (e.g., the light incidence surface) toward another side surface (e.g., the counter surface) facing the one side surface up to a predetermined distance, such that the light guide plate <NUM> becomes thinner up to the predetermined distance and then have substantially uniform thickness past the predetermined distance.

In the optical member <NUM> according to an exemplary embodiment, the light source <NUM> may be disposed adjacent to at least one side surface <NUM> of the light guide plate <NUM>. In <FIG>, a plurality of light-emitting diode (LED) light sources <NUM> are mounted on a printed circuit board <NUM>, and are disposed adjacent to a side surface 10S1 of the light guide plate <NUM>. However, embodiments of the inventive concept are not limited thereto, and the LED light sources <NUM>, for example, may be disposed adjacent to side surfaces 10S1 and 10S3 along both long sides or may be disposed adjacent to a side surface 10S2 or 10S4 along one short side, or the side surfaces 10S2 and 10S4 at both short sides. As shown in <FIG>, the side surface 10S1 of the light guide plate <NUM> adjacent to the light source <NUM> may be a light incidence surface, to which light of the light source <NUM> is directly incident, and the side surface 10S3 at the other long side facing the side surface 10S1 may be a counter surface.

The light guide plate <NUM> may include an inorganic material. For example, the light guide plate <NUM> may be made of glass.

Optical interfaces may be formed at surfaces where the layers <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> of the optical member <NUM> meet each other. The optical member <NUM> may include a plurality of optical interfaces 30a, 30b, 50a, and 50b. Each of the optical interfaces 30a, 30b, 50a, and 50b may be substantially parallel to the upper surface 10a of the light guide plate <NUM>.

The wavelength conversion underlying layer <NUM> is disposed on the upper surface 10a of the light guide plate <NUM>. The wavelength conversion underlying layer <NUM> may include the low refractive layer <NUM>, the low refractive underlying layer <NUM>, and the low refractive overlying layer <NUM>. The wavelength conversion underlying layer <NUM> may be formed directly on the upper surface 10a of the light guide plate <NUM> to contact the upper surface 10a of the light guide plate <NUM>. The wavelength conversion underlying layer <NUM> is interposed between the light guide plate <NUM> and the wavelength conversion layer <NUM> to help total reflection of the optical member <NUM>.

More specifically, in order for the light guide plate <NUM> to efficiently guide light from the light incidence surface 10S1 toward the counter surface 10S3, effective total internal reflection should occur in the light guide plate <NUM>. One of the conditions under which total internal reflection can occur in the light guide plate <NUM> is that a refractive index of the light guide plate <NUM> is greater than a refractive index of a medium that forms an optical interface with the light guide plate <NUM>. As the refractive index of the medium that forms the optical interface with the light guide plate <NUM> is lower, a total reflection critical angle becomes smaller, leading to more total internal reflections.

For example, when the light guide plate <NUM> is made of glass having a refractive index of about <NUM>, sufficient total reflection may occur on the lower surface 10b of the light guide plate <NUM>, because the lower surface 10b is exposed to an air layer having a refractive index of about <NUM>, and thus, forms an optical interface with the air layer.

On the other hand, since other optical functional layers are integrally laminated on the upper surface 10a of the light guide plate <NUM>, it may be difficult to achieve sufficient total reflection on the upper surface 10a as compared with the lower surface 10b. For example, if a material layer having a refractive index of <NUM> or more is laminated on the upper surface 10a of the light guide plate <NUM>, total reflection may not occur on the upper surface 10a of the light guide plate <NUM>. In addition, if a material layer having a refractive index of, e.g., about <NUM>, which is slightly less than that of the light guide plate <NUM>, is laminated on the upper surface 10a of the light guide plate <NUM>, while total internal reflection may occur on the upper surface 10a of the light guide plate <NUM>, sufficient total reflection may not occur due to increased critical angle. The wavelength conversion layer <NUM> laminated on the upper surface 10a of the light guide plate <NUM> typically has a refractive index of about <NUM>. If this wavelength conversion layer <NUM> is directly laminated on the upper surface 10a of the light guide plate <NUM>, it may be difficult to have sufficient total reflection on the upper surface 10a of the light guide plate <NUM>.

The low refractive layer <NUM> interposed between the light guide plate <NUM> and the wavelength conversion layer <NUM> to form an interface with the upper surface 10a of the light guide plate <NUM> has a refractive lower than that of the light guide plate <NUM>, so that total reflection may occur on the upper surface 10a of the light guide plate <NUM>. In addition, the low refractive layer <NUM> has a refractive less than that of the wavelength conversion layer <NUM>, which is a material layer disposed on the low refractive layer <NUM>, so that more total reflection can occur than when the wavelength conversion layer <NUM> is disposed directly on the upper surface 10a of the light guide plate <NUM>.

When the low refractive underlying layer <NUM> is disposed on the light guide plate <NUM>, total reflection may also occur at an interface between the light guide plate <NUM> and the low refractive underlying layer <NUM>, due to the difference in refractive index between the light guide plate <NUM> and the low refractive underlying layer <NUM>. However, light incident on the interface at an angle smaller than the total reflection critical angle may proceed toward the low refractive underlying layer <NUM>. Then, light may be reflected or refracted again at an interface between the low refractive underlying layer <NUM> and the low refractive layer <NUM>. When the refractive index of the low refractive layer <NUM> is less than the refractive index of the low refractive underlying layer <NUM>, total reflection may also occur at the interface. When the optical member <NUM> includes the low refractive underlying layer <NUM>, the low refractive underlying layer <NUM> is interposed between the light guide plate <NUM> and the low refractive layer <NUM>. However, it is the difference in refractive index between the light guide plate <NUM> and the low refractive layer <NUM> that ultimately determines the critical angle of total reflection. Since the difference in refractive index increases as the refractive index of the low refractive layer <NUM> is smaller, the total reflection critical angle may become smaller, leading to more total reflections.

The wavelength conversion underlying layer <NUM> interposed between the light guide plate <NUM> and the wavelength conversion layer <NUM> to form an interface with the upper surface 10a of the light guide plate <NUM> may include the low refractive layer <NUM>. The low refractive layer <NUM> has a refractive less than that of the light guide plate <NUM>, so that total reflection may occur on a lower surface 30b of the low refractive layer <NUM>. In addition, the low refractive layer <NUM> has a refractive index less than that of the wavelength conversion layer <NUM>, which is a material layer disposed on the low refractive layer <NUM>, so that more total reflection can occur than when the wavelength conversion layer <NUM> is disposed directly on the upper surface 10a of the light guide plate <NUM>.

The difference between the refractive index of the light guide plate <NUM> and the refractive index of the low refractive layer <NUM> is <NUM> or more. When the refractive index of the low refractive layer <NUM> is less than the refractive index of the light guide plate <NUM> by <NUM> or more, sufficient total reflection may occur on the lower surface 30b of the low refractive layer <NUM>. There is no upper limit on the difference between the refractive index of the light guide plate <NUM> and the refractive index of the low refractive layer <NUM>. However, considering the typical material of the light guide plate <NUM> and the typical refractive index of the low refractive layer <NUM>, the difference between the refractive index of the light guide plate <NUM> and the refractive index of the low refractive layer <NUM> may be <NUM> or less. The refractive index of the low refractive layer <NUM> is in the range of <NUM> to <NUM>. Generally, as the refractive index of a solid medium becomes closer to <NUM>, the manufacturing cost increases exponentially. When the refractive index of the low refractive layer <NUM> is <NUM> or more, an excessive increase in the manufacturing cost can be prevented. In addition, the low refractive layer <NUM> having a refractive index of <NUM> or less is advantageous in terms of sufficiently reducing the total reflection critical angle of the upper surface 10a of the light guide plate <NUM>. In an exemplary embodiment, the low refractive layer <NUM> having a refractive index of about <NUM> may be applied.

To have the above-mentioned low refractive index, the low refractive layer <NUM> may include voids. The voids may be made of vacuum or may be filled with an air layer, gas, or the like. The spaces of the voids may be defined by particles or a matrix, which is further described in more detail below with reference to <FIG> and <FIG>.

<FIG> and <FIG> are cross-sectional views of low refractive layers according to exemplary embodiments.

In an exemplary embodiment, a low refractive layer <NUM> may include a plurality of particles PT, a matrix MX surrounding the particles PT and formed as a single piece, and a plurality of voids VD, as shown in <FIG>. The particles PT may be a filler that adjusts the refractive index and mechanical strength of the low refractive layer <NUM>.

The particles PT may be dispersed within the matrix MX of the low refractive layer <NUM>, and the voids VD may be formed in open portions of the matrix MX. For example, after the particles PT and the matrix MX are mixed in a solvent, and when the mixture is dried and/or cured, the solvent may be evaporated. At this time, the voids VD may be formed between portions of the matrix MX.

In an exemplary embodiment, a low refractive layer <NUM> may include a matrix MX and voids VD without particles, as shown in <FIG>. For example, the low refractive layer <NUM> may include the matrix MX formed as a single piece, like foam resin, and a plurality of voids VD disposed in the matrix MX.

When the refractive layer <NUM> includes the voids VD as illustrated in <FIG> and <FIG>, a total refractive index of the low refractive layer <NUM> may have a value between a refractive index of the particles PT/ matrix MX and a refractive index of the voids VD. When the voids VD are filled with vacuum having a refractive index of <NUM>, or an air layer or gas having a refractive index of about <NUM>, even if a material having a refractive index of <NUM> or more is used as the particles PT/ matrix MX, the total refractive index of the low refractive layer <NUM> may have a value of <NUM> or less, for example, about <NUM>. In an exemplary embodiment, the particles PT may be made of an inorganic material, such as SiO<NUM>, Fe<NUM>O<NUM> or MgF<NUM>, and the matrix MX may be made of an organic material, such as polysiloxane. However, embodiments of the inventive concept are not limited thereto, and other organic materials or inorganic materials can be used.

Referring back to <FIG> and <FIG>, the low refractive layer <NUM> has a thickness of <NUM> to <NUM>. When the thickness of the low refractive layer <NUM> is <NUM> or more, which is a visible light wavelength range, the low refractive layer <NUM> may form an effective optical interface. Therefore, total reflection according to Snell's law may occur well on the lower surface 30b of the low refractive layer <NUM>. A low refractive layer <NUM> that is too thick may go against the thinning of the optical member <NUM>, increase the material cost, and undermine the luminance of the optical member <NUM>. Therefore, the low refractive layer <NUM> may be formed to have a thickness of <NUM> or less. In an exemplary embodiment, the thickness of the low refractive layer <NUM> may be about <NUM>.

The low refractive underlying layer <NUM> is disposed between the light guide plate <NUM> and the low refractive layer <NUM>. The low refractive underlying layer <NUM> may be formed directly on the upper surface 10a of the light guide plate <NUM> to contact the upper surface 10a of the light guide plate <NUM>. In addition, the low refractive underlying layer <NUM> may contact the lower surface 30b of the low refractive layer <NUM>. The low refractive underlying layer <NUM> may be interposed between the light guide plate <NUM> and the low refractive layer <NUM>. The refractive index of the low refractive underlying layer <NUM> may be greater than that of the low refractive layer <NUM>. The low refractive underlying layer <NUM> may have a single-layer structure, and include any one of a low refractive material and a high refractive material. Alternatively, the low refractive underlying layer <NUM> may have a multilayer structure, in which a low refractive material and a high refractive material are alternately laminated. The refractive index of the low refractive material may be <NUM> to <NUM>. The refractive index of the high refractive material may be <NUM> to <NUM>. In an exemplary embodiment, the low refractive material may be SiOx, and the high refractive material may be SiNx. However, the low refractive material and the high refractive material may be various other materials that satisfy the refractive indices described above.

Since the influence of constructive interference or destructive interference of light changes according to the laminated material and laminated thickness of the low refractive underlying layer <NUM>, light transmittance may be changed. That is, the light transmittance can be adjusted by controlling the laminated material and laminated thickness of the low refractive underlying layer <NUM>. In addition, when the low refractive underlying layer <NUM> includes an inorganic layer, the inorganic layer may function as a protective layer that prevents penetration of moisture/oxygen into the low refractive layer <NUM>.

The low refractive overlying layer <NUM> is disposed between the low refractive layer <NUM> and the wavelength conversion layer <NUM>. The low refractive overlaying layer <NUM> may be formed directly on an upper surface of the low refractive layer <NUM> to contact the upper surface of the low refractive layer <NUM>. In addition, the low refractive overlying layer <NUM> may contact a lower surface of the wavelength conversion layer <NUM>. The low refractive overlying layer <NUM> may be interposed between the low refractive layer <NUM> and the wavelength conversion layer <NUM>. The refractive index of the low refractive overlaying layer <NUM> may be greater than that of the low refractive layer <NUM>. The low refractive overlaying layer <NUM> helps to cause total reflection from the upper surface of the low refractive layer <NUM> toward the wavelength conversion layer <NUM>. The low refractive overlying layer <NUM> may have a single-layer structure including any one of a low refractive material and a high refractive material. Alternatively, the low refractive overlying layer <NUM> may have a multilayer structure, in which a low refractive material and a high refractive material are alternately laminated. As in the low refractive underlying layer <NUM>, the refractive index of the low refractive material may be <NUM> to <NUM>. The refractive index of the high refractive material may be <NUM> to <NUM>. In an exemplary embodiment, the low refractive material may be SiOx, and the high refractive material may be SiNx. However, the low refractive material and the high refractive material may include various other materials satisfying the refractive indices described above.

Since the influence of constructive interference or destructive interference of light changes according to the laminated material and laminated thickness of the low refractive overlying layer <NUM>, light transmittance may be changed. That is, the light transmittance can be adjusted by controlling the laminated material and laminated thickness of the low refractive overlying layer <NUM>. In addition, the low refractive overlying layer <NUM> may improve the optical efficiency of the optical member <NUM>. When light transmitted through the low refractive layer <NUM> enters the wavelength conversion layer <NUM> and encounters dispersed scattering particles, light is scattered as its wavelength is changed. Here, part of the scattered light may travel back toward the light guide plate <NUM>. If the low refractive overlying layer <NUM> has a refractive index higher than that of the low refractive layer <NUM>, the light may be totally reflected at the interface between the low refractive overlying layer <NUM> and the low refractive layer <NUM>, and may be reflected back upward, thereby increasing the optical efficiency, such as brightness, of a display.

The low refractive overlying layer <NUM> may entirely overlap the low refractive layer <NUM> to prevent moisture and/or oxygen from penetrating into the low refractive layer <NUM>. That is, the low refractive overlying layer <NUM> may prevent deformation of the low refractive layer <NUM> and secure structural stability by increasing hardness. In addition, the low refractive overlying layer <NUM> including an inorganic layer may prevent moisture and/or oxygen from penetrating into the wavelength conversion layer <NUM> disposed on the low refractive overlying layer <NUM> and the low refractive layer <NUM> disposed under the low refractive overlying layer <NUM>.

The wavelength conversion underlying layer <NUM> may be formed by methods, such as deposition and coating. The wavelength conversion underlying layer <NUM> may be formed on the light guide plate <NUM> in the order of the low refractive underlying layer <NUM>, the low refractive layer <NUM>, and the low refractive overlying layer <NUM>. In an exemplary embodiment, the low refractive underlying layer <NUM> and the low refractive overlying layer <NUM> may be formed of an inorganic layer including an inorganic material by using a chemical vapor deposition method. The low refractive layer <NUM> may be formed of an organic layer including an organic material by using a coating method. Examples of the coating method include slit coating, spin coating, roll coating, spray coating, and inkjet. However, embodiments of the inventive concept are not limited to a particular coating method, and various other lamination methods can be applied.

The wavelength conversion layer <NUM> is disposed on the wavelength conversion underlying layer <NUM>. In an exemplary embodiment, when the wavelength conversion underlying layer <NUM> includes the low refractive overlying layer <NUM>, the wavelength conversion layer <NUM> may be disposed on the upper surface of the low refractive overlying layer <NUM>. In an exemplary embodiment, when the wavelength conversion underlying layer <NUM> does not include the low refractive overlying layer <NUM>, the wavelength conversion layer <NUM> may be disposed on the upper surface of the low refractive layer <NUM>. The wavelength conversion layer <NUM> may include a binder layer and wavelength conversion particles dispersed in the binder layer. The wavelength conversion layer <NUM> may further include scattering particles dispersed in the binder layer, in addition to the wavelength conversion particles.

The binder layer is a medium to which the wavelength conversion particles are dispersed, and may be made of various resin compositions that can be generally referred to as binders. However, embodiments of the inventive concept are not limited thereto, and any medium to which the wavelength conversion particles and/or the scattering particles can be dispersed can be referred to as the binder layer, regardless of its name, additional other functions, constituent material and the like.

The wavelength conversion particles are particles that convert the wavelength of incident light. For example, the wavelength conversion particles may be quantum dots, a fluorescent material, or a phosphorescent material. Specifically, the quantum dots, which are an example of the wavelength conversion particles, are a material having a crystal structure of several nanometers in size. The quantum dots are composed of several hundreds to thousands of atoms, and exhibit a quantum confinement effect in which an energy band gap increases due to the small size of the quantum dots. When light of a wavelength having a higher energy than a band gap is incident on the quantum dots, the quantum dots become in excited-state by absorbing the light, and fall to a ground state while emitting light of a specific wavelength. The emitted light of the specific wavelength has a value corresponding to the band gap. Emission characteristics of the quantum dots from the quantum confinement effect can be adjusted by controlling the size and composition of the quantum dots.

The quantum dots may include at least one of a group II-VI compound, a group II-V compound, a group III-VI compound, a group III-V compound, a group IV-VI compound, a group I-III-VI compound, a group II-IV-VI compound, and a group II-IV-V compound.

A quantum dot may include a core and a shell overcoating the core. The core may be, but is not limited to, at least one of, for example, 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, Fe3O4, Si, and Ge. The shell may include, but is not limited to, at least one of, for example, 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 conversion particles may include a plurality of wavelength conversion particles that convert incident light into light having different wavelengths. For example, the wavelength conversion particles may include first wavelength conversion particles that convert incident light of a specific wavelength into light of a first wavelength and emit light of the first wavelength, and second wavelength conversion particles that convert the incident light of the specific wavelength into light of a second wavelength and emit light of the second wavelength. In an exemplary embodiment, light emitted from the light source <NUM> and then incident on the wavelength conversion particles may be light of a blue wavelength, the first wavelength may be a green wavelength, and the second wavelength may be a red wavelength. For example, the blue wavelength may be a wavelength having a peak at <NUM> to <NUM>, the green wavelength may be a wavelength having a peak at <NUM> to <NUM>, and the red wavelength may be a wavelength having a peak at <NUM> to <NUM>. However, embodiments of the inventive concept are not limited thereto, and all wavelength ranges that can be recognized as blue, green and red may be used.

In the above exemplary embodiment, when blue light incident on the wavelength conversion layer <NUM> passes through the wavelength conversion layer <NUM>, a portion of the blue light may be incident on the first wavelength conversion particles to be converted into the green wavelength and emitted as light of the green wavelength, another portion of the blue light may be incident on the second wavelength conversion particles to be converted into the red wavelength and emitted as light of the red wavelength, and the remaining portion of the blue light may be emitted as it is without entering the first and second wavelength conversion particles. Therefore, light that has passed through the wavelength conversion layer <NUM> includes all of the light of the blue wavelength, the light of the green wavelength, and the light of the red wavelength. If the ratio of the emitted light of the different wavelengths is appropriately adjusted, white light or outgoing light of other colors can be displayed. The light converted by the wavelength conversion layer <NUM> is concentrated in a narrow range of specific wavelengths and has a sharp spectrum with a narrow half width. Therefore, when light of such a spectrum is filtered using a color filter to realize color, color reproducibility can be improved.

Unlike in the above exemplary embodiment, incident light may be light having a short wavelength, such as ultraviolet light, and three types of wavelength conversion particles for converting the incident light into the blue, green and red wavelengths may be disposed in the wavelength conversion layer <NUM> to emit white light.

The wavelength conversion layer <NUM> may further include scattering particles. The scattering particles may be non-quantum dot particles without a wavelength conversion function. The scattering particles may scatter incident light to cause more incident light to enter the wavelength conversion particles. In addition, the scattering particles may uniformly control an output angle of light for each wavelength. Specifically, when a portion of incident light that enters the wavelength conversion particles is emitted after its wavelength is converted by the wavelength conversion particles, the emission direction of the portion of the incident light has random scattering characteristics. If there are no scattering particles in the wavelength conversion layer <NUM>, the green and red wavelengths emitted after colliding with the wavelength conversion particles may have scattering emission characteristics, but the blue wavelength emitted without colliding with the wavelength conversion particles may not have the scattering emission characteristics. Therefore, the emission amount of the blue/green/red wavelength may be varied according to the output angle. The scattering particles may give the scattering emission characteristics even to the blue wavelength emitted without colliding with the wavelength conversion particles, thereby controlling the output angle of light for each wavelength to be similar. The scattering particles may be made of TiO<NUM> or SiO<NUM>.

The wavelength conversion layer <NUM> may be thicker than the low refractive layer <NUM>. The thickness of the wavelength conversion layer <NUM> may be about <NUM> to <NUM>. In an exemplary embodiment, the thickness of the wavelength conversion layer <NUM> may be about <NUM>.

The wavelength conversion layer <NUM> may be formed by a method such as coating. For example, the wavelength conversion layer <NUM> may be formed by slit-coating a wavelength conversion composition on the light guide plate <NUM> having the wavelength conversion underlying layer <NUM>, and drying and curing the wavelength conversion composition. However, embodiments of the inventive concept are not limited to a particular method of forming the wavelength conversion layer <NUM>, and various other lamination methods can be applied.

The wavelength conversion overlying layer <NUM> may be disposed on the wavelength conversion layer <NUM>. The wavelength conversion overlying layer <NUM> may be a passivation layer that prevents the penetration of moisture and/or oxygen (hereinafter, referred to as 'moisture/oxygen'). The wavelength conversion overlying layer <NUM> may include a plurality of laminated layers. Each of the laminated layers may include an inorganic layer or an organic layer. The wavelength conversion overlying layer <NUM> may include at least one inorganic layer. That is, the wavelength conversion overlying layer <NUM> may include a single inorganic layer, a plurality of inorganic layers, or laminated organic and inorganic layers.

Each laminated layer may include a high refractive material, a low refractive material, and/or a transparent organic material. The wavelength conversion overlying layer <NUM> may have a single layer structure including a low refractive material, a high refractive material, or a transparent organic material, or may have a multilayer structure, in which materials having different refractive indices are laminated. In an exemplary embodiment, the high refractive material and the low refractive material may be silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide, titanium oxide, tin oxide, cerium oxide, or silicon oxynitride. In an exemplary embodiment, the high refractive material may be silicon nitride (SiNx), and the low refractive material may be silicon oxide (SiOx). The transparent organic material may be silicone resin, acrylic resin, or epoxy resin.

The wavelength conversion overlying layer <NUM> may entirely overlap the wavelength conversion layer <NUM> and cover an upper surface of the wavelength conversion layer <NUM>. In an exemplary embodiment, the wavelength conversion overlying layer <NUM> may cover only the upper surface of the wavelength conversion layer <NUM>. However, in an exemplary embodiment, the wavelength conversion overlying layer <NUM> may extend further outward so as to cover side surfaces of the wavelength conversion layer <NUM> and side surfaces of the wavelength conversion underlying layer <NUM>.

The thickness of the wavelength conversion overlying layer <NUM> may be <NUM> to <NUM>. In an exemplary embodiment, when the wavelength conversion overlying layer <NUM> does not include an organic layer, the thickness of the wavelength conversion overlying layer <NUM> may be <NUM> to <NUM>. In an exemplary embodiment, when the wavelength conversion overlying layer <NUM> includes an organic layer, the thickness of the wavelength conversion overlying layer <NUM> may be <NUM> to <NUM>. The thickness of the wavelength conversion overlying layer <NUM> may be less than that of the wavelength conversion layer <NUM>. If the thickness of the wavelength conversion overlying layer <NUM> is <NUM> or more, the wavelength conversion overlying layer <NUM> can exert a significant moisture/oxygen penetration preventing function. The wavelength conversion overlying layer <NUM> having a thickness of <NUM> or less is advantageous in terms of thinning and transmittance. However, embodiments of the inventive concept are not limited to a particular thickness of the wavelength conversion overlying layer <NUM>, and the wavelength conversion overlying layer <NUM> may have various thicknesses. The refractive index and thickness of the laminated material of the wavelength conversion overlying layer <NUM> may affect the amount of light extracted through an upper surface, that is, transmittance. This will be described in detail later.

The wavelength conversion overlying layer <NUM> may be formed by methods such as coating and deposition. For example, an inorganic layer including an inorganic material may be formed on the light guide plate <NUM>, on which the wavelength conversion underlying layer <NUM> and the wavelength conversion layer <NUM> are sequentially formed, by using a chemical vapor deposition method. An organic layer including an organic material may be formed on the light guide plate <NUM> by a coating method. However, embodiments of the inventive concept are not limited to a particular method of forming the wavelength conversion overlying layer <NUM>, and various other lamination methods can be applied.

As described above, the optical member <NUM> can perform a light guide function and a wavelength conversion function simultaneously. The optical member <NUM> may include the wavelength conversion underlying layer <NUM> and the wavelength conversion overlying layer <NUM>. The wavelength conversion underlying layer <NUM> may include the low refractive layer <NUM>, the low refractive underlying layer <NUM>, and the low refractive overlying layer <NUM>. The low refractive underlying layer <NUM> and the low refractive overlying layer <NUM> may include a material having a refractive index higher than that of the low refractive layer <NUM>. Since the low refractive underlying layer <NUM> and the low refractive overlying layer <NUM> change the influence of constructive interference or destructive interference of light incident on the optical member <NUM>, they can improve light transmittance. The wavelength conversion overlying layer <NUM> may include a layer made of at least one of a high refractive material and a low refractive material. In addition, the wavelength conversion overlying layer <NUM> may be a multilayer further including a transparent organic material. The wavelength conversion overlying layer <NUM> entirely covers the wavelength conversion layer <NUM> to prevent penetration of moisture/oxygen. In addition, the wavelength conversion overlying layer <NUM> allows light transmitted through the wavelength conversion layer <NUM> to be effectively output to the outside of the optical member <NUM>, thereby improving the optical efficiency.

In addition, the wavelength conversion overlying layer <NUM> disposed on the wavelength conversion layer <NUM> of the optical member <NUM> may lower the manufacturing cost and reduce the thickness, as compared with a wavelength conversion film provided as a separate film. For example, the wavelength conversion film includes a barrier film attached to the upper and lower surfaces of the wavelength conversion layer <NUM>. The barrier film is not only expensive but also has a thickness of <NUM> or more. Thus, the total thickness of the wavelength conversion film may be about <NUM>. On the other hand, the total thickness of the optical member <NUM> according to an exemplary embodiment excluding the light guide plate <NUM> can be maintained at about <NUM> to <NUM>. Thus, the thickness of a display employing the optical member <NUM> can be reduced. In addition, since the expensive barrier film can be omitted from the optical member <NUM>, the manufacturing cost can be managed at a level lower than that when the wavelength conversion film is used.

The laminated structure and thickness of the wavelength conversion underlying layer <NUM> for obtaining maximum light transmittance will now be described. When light passes through media having different refractive indices, reflection and refraction of the light occur at a point where the media having the different refractive indices meet. If the refractive indices and thicknesses of the media can be identified, the transmittance of the laminated structure can be obtained using the Fresnel equations relating to reflection and refraction of light. That is, a simulation for obtaining transmittance according to the laminated structure and thickness of the wavelength conversion underlying layer <NUM> can be performed.

<FIG> is a table illustrating a wavelength conversion underlying layer according to exemplary embodiments, and <FIG> is a graph showing the change in transmittance with respect to the thickness of SiNx on a light guide plate. <FIG> are tables showing the laminated structures and thicknesses for securing the maximum transmittance in each lamination case of the wavelength conversion underlying layer of <FIG>.

<FIG> is a table illustrating conditions for performing a simulation. In <FIG>, a case where each of a low refractive underlying layer and a low refractive overlying layer has two layers will be described as an example. When the low refractive underlying layer and the low refractive overlying layer are omitted or only one of the layers is provided, the omitted layer or layers will be expressed as having a thickness of <NUM>.

Referring to <FIG> and <FIG>, the wavelength conversion underlying layer <NUM> is laminated on the light guide plate <NUM> in the order of the low refractive underlying layer <NUM>, the low refractive layer <NUM>, and the low refractive overlying layer <NUM>. The wavelength conversion underlying layer <NUM> may be interposed between the light guide plate <NUM> and the wavelength conversion layer <NUM>. The low refractive underlying layer <NUM> and the low refractive overlying layer <NUM> may each include two layers or less.

In the simulation conditions, the thickness of each layer is selected in the range of <NUM> to <NUM>. As described above, a thickness of <NUM> indicates that a corresponding layer is not included. In the simulation conditions, the thickness of the low refractive layer <NUM> is set to <NUM>. The layers included in the low refractive underlying layer <NUM> and the low refractive overlying layer <NUM> may be made of a high refractive material and a low refractive material. In an exemplary embodiment, the high refractive material may be silicon nitride (SiNx), and the low refractive material may be silicon oxide (SiOx). The high refractive material will hereinafter be described as SiNx, and the low refractive material will hereinafter be described as SiOx. A layer including the high refractive material and a layer including the low refractive material may be alternately laminated. The refractive indices of the high refractive material and the low refractive material may be greater than that of the low refractive layer <NUM>. The conditions for obtaining the light transmittance of the wavelength conversion underlying layer <NUM> may be divided into four conditions according to the laminated structure.

Referring to <FIG>, the wavelength conversion underlying layer of case <NUM> includes a low refractive underlying layer <NUM> laminated on the light guide plate in the order of the high refractive material and the low refractive material, and a low refractive overlying layer <NUM> laminated on the low refractive layer in the order of the high refractive material and the low refractive material.

The wavelength conversion underlying layer of case <NUM> includes a low refractive underlying layer <NUM> laminated on the light guide plate in the order of a low refractive material and a high refractive material, and a low refractive overlying layer <NUM> laminated on the low refractive layer in the order of a high refractive material and a low refractive material.

The wavelength conversion underlying layer of case <NUM> includes a low refractive underlying layer <NUM> laminated on the light guide plate in the order of a high refractive material and a low refractive material, and a low refractive overlying layer <NUM> laminated on the low refractive layer in the order of a low refractive material and a high refractive material.

The wavelength conversion underlying layer of case <NUM> includes a low refractive underlying layer <NUM> laminated on the light guide plate in the order of a low refractive material and a high refractive material, and a low refractive overlying layer <NUM> laminated on the low refractive layer in the order of a low refractive material and a high refractive material.

<FIG> is a graph showing the change in transmittance in each lamination condition according to the SiNx thickness of the low refractive underlying layer disposed on the light guide plate in case <NUM>. <FIG> is an example of simulation results, and the transmittance of the wavelength conversion underlying layer having laminated structures of other cases can also be obtained in the same manner as in <FIG>. Here, the transmittance denotes the ratio of blue light transmitted through the lower wavelength conversion underlying layer to blue light incident from a light source. In the graph of <FIG>, SiNx refers to a high refractive material, and SiOx refers to a low refractive material.

Referring to <FIG> and <FIG>, the wavelength conversion underlying layer <NUM> on which the simulation of <FIG> is performed has the structure of case <NUM> described above. The wavelength conversion underlying layer <NUM> of case <NUM> includes the low refractive underlying layer <NUM> laminated in the order of SiNx and SiOx, and the low refractive overlying layer <NUM> laminated in the order of SiNx and SiOx. The SiNx of the low refractive underlying layer <NUM> corresponds to SiNx thickness corresponding to the X axis of the graph of <FIG>. That is, in the graph, the thickness of SiNx of the low refractive underlying layer <NUM> has a variable value, and the thickness of SiOx of the low refractive underlying layer <NUM> and the thicknesses of SiNx and SiOx of the low refractive overlying layer <NUM> have specified values. <FIG> illustrates three graphs G1, G2, and G3 showing the change in transmittance with respect to the SiNx thickness of the low refractive underlying layer <NUM> when the thickness of SiOx of the low refractive underlying layer <NUM> is <NUM>, <NUM>, and <NUM>, respectively. Here, the thicknesses of SiNx and SiOx of the low refractive overlying layer <NUM> are each o µm, indicating that the wavelength conversion underlying layer <NUM> does not include the low refractive overlying layer <NUM>.

G1 is a graph showing the change in transmittance when the thickness of SiOx of the low refractive underlying layer <NUM> is <NUM>. G2 is a graph showing the change in transmittance when the thickness of SiOx of the low refractive underlying layer <NUM> is <NUM>. G3 is a graph showing the change in transmittance when the thickness of SiOx of the low refractive underlying layer <NUM> is <NUM>. G1 has the maximum transmittance when the SiNx thickness of the low refractive underlying layer <NUM> is about <NUM>. G2 has the maximum transmittance when the SiNx thickness of the low refractive underlying layer <NUM> is about <NUM> or about <NUM>. G3 has the maximum transmittance when the SiNx thickness of the low refractive underlying layer <NUM> is about <NUM>. That is, when the laminated structure, such as the laminated order and the laminated thickness, is changed, the transmittance also changes. Therefore, the maximum transmittance in each lamination condition can be identified, and, accordingly, each lamination condition having the maximum transmittance can be determined.

<FIG> are tables showing the laminated structures and thicknesses for securing the maximum blue light transmittance in each lamination case of the wavelength conversion underlying layer. In <FIG>, three result values with high transmittance are shown for each lamination case. Glass of <NUM> T indicates the light guide plate having a thickness of <NUM>. The result values are the results of a simulation performed in a case the low refractive layer is <NUM> and the wavelength conversion layer is <NUM>. In <FIG>, SiOx is an example of a low refractive material, and SiNx is an example of a high refractive material.

Referring to <FIG> and <FIG>, result <NUM> of case <NUM> is a result value according to G1 described in <FIG>. Result <NUM> of case <NUM> shows the transmittance of the wavelength conversion underlying layer <NUM> including the low refractive underlying layer <NUM> in which SiNx of <NUM> and SiOx of <NUM> are laminated sequentially on the light guide plate, and including the low refractive overlying layer <NUM> in which SiNx and SiOx are <NUM>, that is, not including the low refractive overlying layer <NUM>. The wavelength conversion underlying layer <NUM> of result <NUM> has a blue light transmittance of <NUM>%. If the maximum blue light transmittance in each case is obtained like this, all of the four cases may have a maximum transmittance of about <NUM>%. Laminated structures of the wavelength conversion underlying layer according to various exemplary embodiments will now be described in detail with reference to <FIG>.

<FIG> are cross-sectional views of wavelength conversion underlying layers <NUM> through <NUM> according to exemplary embodiments. <FIG> show that elements of a wavelength conversion underlying layer can be variously arranged. The wavelength conversion underlying layers <NUM> through <NUM> may each include a low refractive layer <NUM>, and may further include a low refractive underlying layer <NUM> (see <FIG>) and a low refractive overlying layer <NUM> (see <FIG>). In some exemplary embodiments, a wavelength conversion underlying layer does not include a low refractive underlying layer or a low refractive overlying layer. However, in order to effectively induce total reflection and improve light transmittance, the wavelength conversion underlying layers <NUM> through <NUM> may each include at least one of the low refractive underlying layer <NUM> (see <FIG>) and the low refractive overlying layer <NUM> (see <FIG>). The low refractive underlying layer <NUM> (see <FIG>) and the low refractive overlying layer <NUM> (see <FIG>) may have a single-layer structure or a multilayer structure in which a high refractive material and a low refractive material are alternately laminated. SiNx will hereinafter be described as an example of the high refractive material, and SiOx will hereinafter be described as an example of the low refractive material. However, embodiments of the inventive concept are not limited to the above example.

In <FIG>, a low refractive underlying layer <NUM> and a low refractive overlying layer <NUM> of the wavelength conversion underlying layer <NUM> have a single-layer structure. The wavelength conversion underlying layer <NUM> of <FIG> is a structure corresponding to result <NUM> of case <NUM> in <FIG>. That is, in the wavelength conversion underlying layer <NUM> of <FIG>, the low refractive underlying layer <NUM> is a single layer made of a high refractive material, and the low refractive overlying layer <NUM> is a single layer made of a low refractive material. In an exemplary embodiment, the low refractive underlying layer <NUM> is made of SiNx and has a thickness of <NUM>. The low refractive overlying layer <NUM> is made of SiOx and has a thickness of <NUM>. The blue light transmittance of the wavelength conversion underlying layer <NUM> according to the illustrated exemplary embodiment is <NUM>%.

In <FIG>, a low refractive underlying layer 22a and 22b of the wavelength conversion underlying layer <NUM> includes alternately laminated materials having different refractive indices, and a low refractive overlying layer <NUM> is a single-layer structure. The wavelength conversion underlying layer <NUM> of <FIG> is a structure corresponding to result <NUM> and result <NUM> of case <NUM> in <FIG>. That is, in the wavelength conversion underlying layer <NUM> of <FIG>, the low refractive underlying layer 22a and 22b may be a multilayer including a first low refractive underlying layer 22a and a second low refractive underlying layer 22b having different refractive indices, and the low refractive overlying layer <NUM> may be a single layer of a low refractive material. The refractive index of the first low refractive underlying layer 22a may be greater than the refractive index of the second low refractive underlying layer 22b. The second low refractive underlying layer 22b may include the same material as the low refractive overlying layer <NUM>. In an exemplary embodiment, the first low refractive underlying layer 22a is made of SiNx and has a thickness of <NUM>. The second low refractive underlying layer 22b is made of SiOx and has a thickness of <NUM>. The low refractive overlying layer <NUM> is made of SiOx, which is a low refractive material, and has a thickness of <NUM>. Accordingly, the blue light transmittance of the wavelength conversion underlying layer <NUM> is <NUM>%. A wavelength conversion underlying layer <NUM> according to an exemplary embodiment is the same as the wavelength conversion underlying layer <NUM> of the above exemplary embodiment in terms of laminated materials, but is different in the thickness of each layer. The thickness of the first low refractive underlying layer 22a is <NUM>. The thickness of the second low refractive underlying layer 22b is <NUM>. The thickness of the low refractive overlying layer <NUM> is <NUM>. Accordingly, the blue light transmittance of the wavelength conversion underlying layer <NUM> is <NUM>%.

In <FIG>, a low refractive underlying layer 23a and 23b of the wavelength conversion underlying layer <NUM> includes alternately laminated materials having different refractive indices, and a low refractive overlying layer <NUM> has a single-layer structure. The wavelength conversion underlying layer <NUM> of <FIG> is a structure corresponding to result <NUM> and result <NUM> of Case <NUM> in <FIG>. That is, in the wavelength conversion underlying layer <NUM> of <FIG>, the low refractive underlying layer 23a and 23b may be a multilayer including a first low refractive underlying layer 23a and a second low refractive underlying layer 23b having different refractive indices, and the low refractive overlying layer <NUM> may be a single layer of a low refractive material. The wavelength conversion underlying layer <NUM> of <FIG> may include the same number of layers as that in <FIG>. In the illustrated exemplary embodiment of <FIG>, however, the refractive index of the first low refractive underlying layer 23a may be less than that of the second low refractive underlying layer 23b. In addition, the first low refractive underlying layer 23a may include the same material as the low refractive overlying layer <NUM>. In an exemplary embodiment, the first low refractive underlying layer 23a is made of SiOx and has a thickness of <NUM>. The second low refractive underlying layer 23b is made of SiNx and has a thickness of <NUM>. The low refractive overlaying layer <NUM> is made of SiOx and has a thickness of <NUM>. Accordingly, the blue light transmittance of the wavelength conversion underlying layer <NUM> is <NUM>%. A wavelength conversion underlying layer <NUM> according to an exemplary embodiment is the same as the wavelength conversion underlying layer <NUM> of the above exemplary embodiment in terms of laminated materials, but is different in the thickness of each layer. The thickness of the first low refractive underlying layer 23a is <NUM>. The thickness of the second low refractive underlying layer 23b is <NUM>. The thickness of the low refractive overlying layer <NUM> is <NUM>. Accordingly, the blue light transmittance of the wavelength conversion underlying layer <NUM> is <NUM>%.

In <FIG>, the wavelength conversion underlying layer <NUM> does not include a low refractive underlying layer, and a low refractive overlying layer 44a and 44b has a multilayer structure. The wavelength conversion underlying layer <NUM> of <FIG> is a structure corresponding to result <NUM> of Case <NUM> in <FIG>. That is, in the wavelength conversion underlying layer <NUM> of <FIG>, the low refractive underlying layer is not provided, that is, has a thickness of <NUM>, and the low refractive overlying layer 44a and 44b may be a multilayer including a first low refractive overlying layer 44a and a second low refractive overlying layer 44b having different refractive indices. The refractive index of the first low refractive overlying layer 44a may be less than the refractive index of the second low refractive overlying layer 44b. In an exemplary embodiment, the first low refractive overlaying layer 44a is made of SiOx and has a thickness of <NUM>. The second low refractive overlying layer 44b is made of SiNx and has a thickness of <NUM>. Accordingly, the blue light transmittance of the wavelength conversion underlying layer <NUM> is <NUM>%.

In <FIG>, a low refractive underlying layer <NUM> of the wavelength conversion underlying layer <NUM> is a single-layer structure, and a low refractive overlying layer 45a and 45b is a multilayer structure in which materials having different refractive indices are alternately laminated. The wavelength conversion underlying layer <NUM> of <FIG> is a structure corresponding to result <NUM> of Case <NUM> in <FIG>. That is, in the wavelength conversion underlying layer <NUM> of <FIG>, the low refractive underlying layer <NUM> may have a single-layer structure including a high refractive material, and the low refractive overlying layer 45a and 45b may be a multilayer including a first low refractive overlying layer 45a and a second low refractive overlying layer 45b having different refractive indices. The refractive index of the first low refractive overlying layer 45a may be less than the refractive index of the second low refractive overlying layer 45b. The low refractive underlying layer <NUM> may be made of the same material as the second low refractive overlying layer 45b. In an exemplary embodiment, the low refractive underlying layer <NUM> is made of SiNx and has a thickness of <NUM>. The first low refractive overlying layer 45a is made of SiOx and has a thickness of <NUM>. The second low refractive overlying layer 45b is made of SiNx and has a thickness of <NUM>. Accordingly, the blue light transmittance of the wavelength conversion underlying layer <NUM> is <NUM>%.

In <FIG>, a low refractive underlying layer <NUM> of the wavelength conversion underlying layer <NUM> has a single-layer structure, and a low refractive overlying layer 46a and 46b has a multilayer structure in which materials having different refractive indices are alternately laminated. The wavelength conversion underlying layer <NUM> of <FIG> is a structure corresponding to result <NUM> and result <NUM> of Case <NUM> in <FIG>. That is, in the wavelength conversion underlying layer <NUM> of <FIG>, the low refractive underlying layer <NUM> may have a single-layer structure including a high refractive material, and the low refractive overlying layer 46a and 46b may be a multilayer including a first low refractive overlying layer 46a and a second low refractive overlying layer 46b having different refractive indices. The refractive index of the first low refractive overlying layer 46a may be less than the refractive index of the second low refractive overlying layer 46b. The wavelength conversion underlying layer <NUM> in <FIG> may include the same number of layers as that in <FIG>. In the exemplary embodiment of <FIG>, however, the low refractive underlying layer <NUM> may be made of a low refractive material. In addition, the low refractive underlying layer <NUM> may be made of the same material as the first low refractive overlying layer 46a. In an exemplary embodiment, the low refractive underlying layer <NUM> is made of SiOx and has a thickness of <NUM>. The first low refractive overlying layer 46a is made of SiOx and has a thickness of <NUM>. The second low refractive overlying layer 46b is made of SiNx and has a thickness of <NUM>. Accordingly, the blue light transmittance of the wavelength conversion underlying layer <NUM> is <NUM>%. A wavelength conversion underlying layer <NUM> according to an exemplary embodiment is the same as the wavelength conversion underlying layer <NUM> of the above exemplary embodiment in terms of laminated materials, but is different in the thickness of each layer. The thickness of the low refractive underlying layer <NUM> is <NUM>. The thickness of the first low refractive overlying layer 46a is <NUM>. The thickness of the second low refractive overlying layer 46b is <NUM>. Accordingly, the blue light transmittance of the wavelength conversion underlying layer <NUM> is <NUM>%.

In <FIG>, a low refractive underlying layer 27a and 27b and a low refractive overlying layer 47a and 47b of the wavelength conversion underlying layer <NUM> have a multilayer structure in which materials having different refractive indices are alternately laminated. The wavelength conversion underlying layer <NUM> of <FIG> is a structure corresponding to result <NUM> and result <NUM> of case <NUM> in <FIG>. That is, in the wavelength conversion underlying layer <NUM> of <FIG>, the low refractive underlying layer 27a and 27b may be a multilayer including a first low refractive underlying layer 27a and a second low refractive underlying layer 27b having different refractive indices, and the low refractive overlying layer 47a and 47b may be a multilayer including a first low refractive overlying layer 47a and a second low refractive overlying layer 47b having different refractive indices. The refractive index of the first low refractive underlying layer 27a may be greater than that of the second low refractive underlying layer 27b. The refractive index of the first low refractive overlying layer 47a may be less than that of the second low refractive overlying layer 47b. In addition, the first low refractive underlying layer 27a may be made of the same material as the second low refractive overlying layer 47b, and the second low refractive underlying layer 27b may be made of the same material as the first low refractive overlying layer 47a. In an exemplary embodiment, the first low refractive underlying layer 27a is made of SiNx and has a thickness of <NUM>. The second low refractive underlying layer 27b is made of SiOx and has a thickness of <NUM>. The first low refractive overlying layer 47a is made of SiOx and has a thickness of <NUM>. The second low refractive overlying layer 47b is made of SiNx and has a thickness of <NUM>. Accordingly, the blue light transmittance of the wavelength conversion underlying layer <NUM> is <NUM>%. A wavelength conversion underlying layer <NUM> according to an embodiment is the same as the wavelength conversion underlying layer <NUM> of the above exemplary embodiment in terms of laminated materials, but is different in the thickness of each layer. The thickness of the first low refractive underlying layer 27a is <NUM>. The thickness of the second low refractive overlying layer 47b is <NUM>. The thickness of the first low refractive overlying layer 47a is <NUM>. The thickness of the second low refractive overlying layer 47b is <NUM>. Accordingly, the blue light transmittance of the wavelength conversion underlying layer <NUM> is <NUM>%.

In <FIG>, the wavelength conversion underlying layer <NUM> does not include a low refractive overlying layer, contrary to <FIG>, and a low refractive underlying layer 28a and 28b has a multilayer structure. The wavelength conversion underlying layer <NUM> of <FIG> is a structure corresponding to result <NUM> of case <NUM> in <FIG>. That is, in the wavelength conversion underlying layer <NUM> of <FIG>, the low refractive overlying layer is not provided, that is, has a thickness of <NUM>, and the low refractive underlying layer 28a and 28b may be a multilayer including a first low refractive underlying layer 28a and a second low refractive underlying layer 28b having different refractive indices. The refractive index of the first low refractive underlying layer 28a may be greater than that of the second low refractive underlying layer 28b. In an exemplary embodiment, the first low refractive underlying layer 28a is made of SiNx and has a thickness of <NUM>. The second low refractive underlying layer 28b is made of SiOx and has a thickness of <NUM>. Accordingly, the blue light transmittance of the wavelength conversion underlying layer <NUM> is <NUM>%.

<FIG> is a table illustrating lamination cases of a wavelength conversion overlying layer, and <FIG> is a graph showing the change in transmittance with respect to the thickness of SiNx on a wavelength conversion layer. The table in <FIG> shows the laminated structures and thicknesses for securing the maximum transmittance in each lamination case of the wavelength conversion overlying layer.

Referring to <FIG> and <FIG>, the table illustrates conditions for performing a simulation. The wavelength conversion overlying layer <NUM> may be disposed on the wavelength conversion layer <NUM>. The wavelength conversion overlying layer <NUM> may include a high refractive material, a low refractive material, and a transparent organic material. In an exemplary embodiment, the high refractive material may be silicon nitride (SiNx), and the low refractive material may be silicon oxide (SiOx). The high refractive material will hereinafter be described as SiNx, and the low refractive material will hereinafter be described as SiOx. The transparent organic material may be silicone resin, acrylic resin, or epoxy resin. Each layer including the high refractive material or the low refractive material may have a thickness of <NUM> to <NUM>. A layer including the transparent organic material may have a thickness of <NUM> to <NUM>. A thickness of <NUM> indicates that a corresponding layer is not included. There may be a total of six conditions according to the laminated structure of layers including the high refractive material, the low refractive material, and the transparent organic material. Hereinafter, three conditions exhibiting substantially high light transmittance will be described below.

The wavelength conversion overlying layer <NUM> of case <NUM> may have a structure in which layers including a high refractive material, a low refractive material, and a transparent organic material are sequentially laminated in this order on the wavelength conversion layer <NUM>.

The wavelength conversion overlying layer <NUM> of case <NUM> may have a structure in which layers including a high refractive material, a transparent organic material, and a low refractive material are sequentially laminated in this order on the wavelength conversion layer <NUM>.

The wavelength conversion overlying layer <NUM> of case <NUM> may include a structure in which layers including a transparent organic material, a high refractive material, and a low refractive material are sequentially laminated in this order on the wavelength conversion layer <NUM>.

<FIG> is a graph showing the change in transmittance with respect to the thickness of SiNx disposed on the wavelength conversion layer <NUM> in case <NUM> of <FIG>. <FIG> is an example of simulation results, and the transmittance of the wavelength conversion overlying layer <NUM> having laminated structures of other cases can also be obtained in the same manner as in <FIG>. Here, the transmittance denotes the ratio of white light transmitted through the lower wavelength conversion overlying layer <NUM> to white light incident through the wavelength conversion layer <NUM>. In the graph of <FIG>, SiNx refers to a high refractive material, and SiOx refers to a low refractive material.

Referring to <FIG>, it can be seen that the transmittance of the wavelength conversion overlying layer <NUM> changes as the SiNx thickness of the wavelength conversion overlying layer <NUM> changes. Since the influence of constructive interference or destructive interference of light changes according to the thickness of SiNx, the light transmittance also changes. As the thickness of SiNx increases, the value of the maximum light transmittance tends to decrease due to the absorption of light by the material. The wavelength conversion overlying layer <NUM> according to case <NUM> has the maximum transmittance when the SiNx thickness is about <NUM>. In this way, the maximum transmittance in each lamination condition can be obtained by changing the laminated structure, such as the laminated order and laminated thickness of the wavelength conversion overlying layer <NUM>, according to case <NUM> through case <NUM> shown in <FIG>.

<FIG> are tables showing the laminated structures and thicknesses for securing the maximum transmittance in each lamination case of the wavelength conversion overlying layer. In <FIG>, three result values with high transmittance are shown for each lamination case. In <FIG>, SiNx is an example of a high refractive material, and SiOx is an example of a low refractive material. OC refers to a transparent organic material. If the maximum light transmittance in each case is obtained, the wavelength conversion overlying layer <NUM> may have a maximum light transmittance of <NUM> to <NUM>%. Laminated structures of the wavelength conversion overlying layer <NUM> according to various exemplary embodiments will now be described in detail with reference to <FIG>.

<FIG> are cross-sectional views of wavelength conversion overlying layers <NUM> through <NUM> according to exemplary embodiments. The wavelength conversion overlying layers in <FIG> show that elements of a wavelength conversion overlying layer can be variously arranged. In order to effectively transmit light and prevent moisture/oxygen from penetrating into the wavelength conversion layer <NUM>, the wavelength conversion overlying layers <NUM> through <NUM> may each have a multilayer structure in which layers including at least two of a high refractive material, a low refractive material, and a transparent organic material are laminated.

In <FIG>, a wavelength conversion overlying layer 61a and 61b is disposed on the wavelength conversion layer <NUM> and has a multilayer structure including a first wavelength conversion overlying layer 61a and a second wavelength conversion overlying layer 61b. The wavelength conversion overlying layer 61a and 61b of <FIG> is a structure corresponding to result <NUM> through result <NUM> of case <NUM> in <FIG>. That is, the wavelength conversion overlying layer 61a and 61b of <FIG> may not include a high refractive material and may be a multilayer including the first wavelength conversion overlying layer 61a and the second wavelength conversion overlying layer 61b having different refractive indices. The refractive index of the first wavelength conversion overlying layer 61a may be greater than that of the second wavelength conversion overlying layer 61b. In an exemplary embodiment, the first wavelength conversion overlying layer 61a is made of SiOx and has a thickness of <NUM>. The second wavelength conversion overlying layer 61b is made of a transparent organic material and has a thickness of <NUM>. Accordingly, the white light transmittance of the wavelength conversion overlying layer 61a and 61b is <NUM>%. A wavelength conversion overlying layer 61a and 61b according to an exemplary embodiment is the same as the wavelength conversion overlying layer 61a and 61b of the above exemplary embodiment in terms of laminated materials, but is different in the thickness of each layer. The thickness of the first wavelength conversion overlying layer 61a is <NUM>. The thickness of the second wavelength conversion overlying layer 61b is <NUM>. Accordingly, the white light transmittance of the wavelength conversion overlying layer 61a and 61b is <NUM>%. A wavelength conversion overlying layer 61a and 61b according to an exemplary embodiment is the same as the wavelength conversion overlying layer 61a and 61b of the above exemplary embodiment in terms of laminated materials, but is different in the thickness of each layer. The thickness of the first wavelength conversion overlying layer 61a is <NUM>. The thickness of the second wavelength conversion overlying layer 61b is <NUM>. Accordingly, the white light transmittance of the wavelength conversion overlying layer 61a and 61b is <NUM>%.

In <FIG>, a wavelength conversion overlying layer 62a and 62b is disposed on the wavelength conversion layer <NUM> and has a multilayer structure including a first wavelength conversion overlying layer 62a and a second wavelength conversion overlying layer 62b. The wavelength conversion overlying layer 62a and 62b of <FIG> is a structure corresponding to result <NUM> through result <NUM> of case <NUM> in <FIG>. That is, the wavelength conversion overlying layer 62a and 62b of <FIG> may not include a transparent organic material, and may be a multilayer including the first wavelength conversion overlying layer 62a and the second wavelength conversion overlying layer 62b having different refractive indices. The refractive index of the first wavelength conversion overlying layer 62a may be greater than that of the second wavelength conversion overlying layer 62b. In an exemplary embodiment, the first wavelength conversion overlying layer 62a is made of SiNx and has a thickness of <NUM>. The second wavelength conversion overlying layer 62b is made of SiOx and has a thickness of <NUM>. Accordingly, the white light transmittance of the wavelength conversion overlying layer 62a and 62b is <NUM>%. A wavelength conversion overlying layer 62a and 62b according to an exemplary embodiment is the same as the wavelength conversion overlying layer 62a and 62b of the above exemplary embodiment in terms of laminated materials, but is different in the thickness of each layer. The thickness of the first wavelength conversion overlying layer 62a is <NUM>. The thickness of the second wavelength conversion overlying layer 62b is <NUM>. Accordingly, the white light transmittance of the wavelength conversion overlying layers 62a and 62b is <NUM>%. A wavelength conversion overlying layer 62a and 62b according to an exemplary embodiment is the same as the wavelength conversion overlying layer 62a and 62b of the above exemplary embodiment in terms of laminated materials, but is different in the thickness of each layer. The thickness of the first wavelength conversion overlying layer 62a is <NUM>. The thickness of the second wavelength conversion overlying layer 62b is <NUM>. Accordingly, the white light transmittance of the wavelength conversion overlying layer 62a and 62b is <NUM>%.

In <FIG>, a wavelength conversion overlying layer 63a and 63b is disposed on the wavelength conversion layer <NUM> and has a multilayer structure including a first wavelength conversion overlying layer 63a and a second wavelength conversion overlying layer 63b. The wavelength conversion overlying layer 63a and 63b of <FIG> is a structure corresponding to result <NUM> of case <NUM> in <FIG>. That is, the wavelength conversion overlying layer 63a and 63b of <FIG> may not include a low refractive material and may be a multilayer including the first wavelength conversion overlying layer 63a and the second wavelength conversion overlying layer 63b having different refractive indices. The refractive index of the first wavelength conversion overlying layer 63a may be less than that of the second wavelength conversion overlying layer 63b. In an exemplary embodiment, the first wavelength conversion overlying layer 63a is made of a transparent organic material and has a thickness of <NUM>. The second wavelength conversion overlying layer 63b is made of SiNx and has a thickness of <NUM>. Accordingly, the white light transmittance of the wavelength conversion overlying layer 63a and 63b is <NUM>%.

In <FIG>, a wavelength conversion overlying layer 64a, 64b and 64c is disposed on the wavelength conversion layer <NUM> and has a multilayer structure including a first wavelength conversion overlying layer 64a, a second wavelength conversion overlying layer 64b and a third wavelength conversion overlying layer 64c. The wavelength conversion overlying layer 64a, 64b, and 64c of <FIG> is a structure corresponding to result <NUM> and result <NUM> of case <NUM> in <FIG>. That is, the wavelength conversion overlying layer 64a, 64b, and 64c of <FIG> may be a multilayer including the first wavelength conversion overlying layer 64a, the second wavelength conversion overlying layer 64b, and the third wavelength conversion overlying layer 64c having different refractive indices. The refractive index of the first wavelength conversion overlying layer 64a may be the smallest, and the refractive index of the second wavelength conversion overlying layer 64b may be the largest. The refractive index of the third wavelength conversion overlying layer 64c may be greater than the refractive index of the first wavelength conversion overlying layer 64a and less than the refractive index of the second wavelength conversion overlying layer 64b. In an exemplary embodiment, the first wavelength conversion overlying layer 64a is made of a transparent organic material and has a thickness of <NUM>. The second wavelength conversion overlying layer 64b is made of SiNx and has a thickness of <NUM>. The third wavelength conversion overlying layer 64c is made of SiOx and has a thickness of <NUM>. Accordingly, the white light transmittance of the wavelength conversion overlying layer 64a, 64b, and 64c is <NUM>%. A wavelength conversion overlying layer 64a, 64b, and 64c according to an exemplary embodiment is the same as the wavelength conversion overlying layer 64a, 64b, and 64c of the above exemplary embodiment in terms of laminated materials, but is different in the thickness of each layer. The thickness of the first wavelength conversion overlying layer 64a is <NUM>. The thickness of the second wavelength conversion overlying layer 64b is <NUM>. The thickness of the third wavelength conversion overlying layer 64c is <NUM>. Accordingly, the white light transmittance of the wavelength conversion overlying layer 64a, 64b and 64c is <NUM>%.

<FIG> are cross-sectional views of optical members <NUM> through <NUM> according to exemplary embodiments. The optical members <NUM> of <FIG> show that the wavelength conversion underlying layer <NUM> and the wavelength conversion overlying layer <NUM> described above can be variously combined. The structures of the eight wavelength conversion underlying layers <NUM> through <NUM> described above with reference to <FIG> and the structures of the four wavelength conversion overlying layers <NUM> through <NUM> described above with reference to <FIG> can be combined to produce <NUM> optical members (<NUM>, <NUM>, <NUM>) according to exemplary embodiments. However, the laminated structure of an optical member is not limited to the above examples, and various other laminated structures can be applied in embodiments of the invention. In optical members according to exemplary embodiments, the wavelength conversion underlying layers <NUM> through <NUM> described above with reference to <FIG> may be divided into the wavelength conversion underlying layer <NUM> not including the low refractive underlying layer <NUM>, the wavelength conversion underlying layer <NUM> not including the low refractive overlying layer <NUM>, and the wavelength conversion underlying layers <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> including both the low refractive underlying layer and the low refractive overlying layer. The wavelength conversion overlying layer <NUM> may be any one of the four wavelength conversion overlying layers <NUM> through <NUM> described above with reference to <FIG>.

The final light transmittance of the optical member <NUM> may be obtained by multiplying the blue light transmittance of the wavelength conversion underlying layer <NUM> by the white light transmittance of the wavelength conversion overlying layer <NUM>.

Referring to <FIG>, the optical member <NUM> according to an exemplary embodiment may include a wavelength conversion underlying layer <NUM> and a wavelength conversion overlying layer 60a. The wavelength conversion underlying layer <NUM> may include a low refractive layer <NUM> and a low refractive overlying layer 40a, but may not include a low refractive underlying layer. The wavelength conversion underlying layer <NUM> may be the wavelength conversion underlying layer <NUM> described in <FIG>. That is, the wavelength conversion underlying layer <NUM> may be a wavelength conversion underlying layer not including a low refractive underlying layer and including the low refractive overlying layer 40a having a multilayer structure. The wavelength conversion overlying layer 60a may have a multilayer structure in which layers including inorganic or organic materials are laminated.

Referring to <FIG>, the optical member <NUM> according to an exemplary embodiment may include a wavelength conversion underlying layer <NUM> and a wavelength conversion overlying layer 60b. The wavelength conversion underlying layer <NUM> may include a low refractive underlying layer 20b and a low refractive layer <NUM>, but may not include a low refractive overlying layer. The wavelength conversion underlying layer <NUM> may be the wavelength conversion underlying layer <NUM> described in <FIG>. That is, the wavelength conversion underlying layer <NUM> may be a wavelength conversion underlying layer not including a low refractive overlying layer and including the low refractive underlying layer 20b having a multilayer structure. The wavelength conversion overlying layer 60b may have a multilayer structure in which layers including inorganic or organic materials are laminated.

Referring to <FIG>, the optical member <NUM> according to an exemplary embodiment may include a wavelength conversion underlying layer <NUM> and a wavelength conversion overlying layer 60c. The wavelength conversion underlying layer <NUM> may include a low refractive underlying layer 20c, a low refractive layer <NUM>, and a low refractive overlying layer 40c. The wavelength conversion underlying layer <NUM> may be any one of the wavelength conversion underlying layers <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> according to exemplary embodiments, excluding the wavelength conversion underlying layers <NUM> and <NUM> of <FIG> and <FIG> from the wavelength conversion underlying layers <NUM> through <NUM> described above with reference to <FIG>. That is, the wavelength conversion underlying layer <NUM> may include the low refractive underlying layer 20c having a single-layer structure or a multilayer structure, and the low refractive overlying layer 40c having a single-layer structure or a multilayer structure. The wavelength conversion overlying layer 60c may be a multilayer structure in which layers including inorganic or organic materials are laminated.

<FIG> is a cross-sectional view of a display <NUM> according to an exemplary embodiment.

Referring to <FIG>, the display <NUM> includes a light source <NUM>, an optical member <NUM> disposed on an emission path of the light source <NUM>, and a display panel <NUM> disposed above the optical member <NUM>.

All optical members according to the above-described exemplary embodiments can be applied as the optical member <NUM>. In <FIG>, a display will be described as including the optical member <NUM> of <FIG> as an example.

The light source <NUM> is disposed on a side of the optical member <NUM>. The light source <NUM> may be disposed adjacent to a light incidence surface 10S1 of a light guide plate <NUM> of the optical member <NUM>. The light source <NUM> may include a plurality of point light sources or linear light sources. The point light sources may be LED light sources <NUM>. The LED light sources <NUM> may be mounted on a printed circuit board <NUM>. The LED light sources <NUM> may emit light of a blue wavelength.

As illustrated in <FIG>, the LED light sources <NUM> may be top-emitting LEDs that emit light through their top surfaces. In this case, the printed circuit board <NUM> may be disposed on a sidewall <NUM> of the housing <NUM>.

The light of the blue wavelength emitted from the LED light sources <NUM> is incident on the light guide plate <NUM> of the optical member <NUM>. The light guide plate <NUM> of the optical member <NUM> guides the light and outputs the light through an upper surface 10a or a lower surface 10b. A wavelength conversion layer <NUM> of the optical member <NUM> converts part of the light of the blue wavelength incident from the light guide plate <NUM> into other wavelengths, such as a green wavelength and a red wavelength. The light of the green wavelength and the light of the red wavelength are emitted upward together with the unconverted light of the blue wavelength toward the display panel <NUM>.

Scattering patterns <NUM> may be disposed on the lower surface 10b of the light guide plate <NUM>. The scattering patterns <NUM> change the angle of light propagating in the light guide plate <NUM> through total reflection and output the light having the changed angle to the outside of the light guide plate <NUM>.

In an exemplary embodiment, the scattering patterns <NUM> may be provided as a separate layer or separate patterns. For example, a pattern layer including protruding patterns and/or concave groove patterns may be formed on the lower surface 10b of the light guide plate <NUM>, or printed patterns may be formed on the lower surface 10b of the light guide plate <NUM> to function as the scattering patterns <NUM>.

In an exemplary embodiment, the scattering patterns <NUM> may be formed of the surface shape of the light guide plate <NUM> itself. For example, concave grooves may be formed on the lower surface 10b of the light guide plate <NUM> to function as the scattering patterns <NUM>.

The arrangement density of the scattering patterns <NUM> may differ depending on area. For example, the arrangement density of the scattering patterns <NUM> may be low in an area adjacent to the light incidence surface 10s1 to which a relatively large amount of light is provided, and may be high in an area adjacent to a counter surface 10s3 to which a relatively small amount of light is provided.

The display <NUM> may further include a reflective member <NUM> disposed under the optical member <NUM>. The reflective member <NUM> may include a reflective film or a reflective coating layer. The reflective member <NUM> reflects light output from the lower surface 10b of the light guide plate <NUM> of the optical member <NUM> back into the light guide plate <NUM>.

The display panel <NUM> is disposed above the optical member <NUM>. The display panel <NUM> receives light from the optical member <NUM> and displays a screen. Examples of such a light-receiving display panel that receives light and displays a screen include a liquid crystal display panel and an electrophoretic panel. Hereinafter, the display panel <NUM> will be described as including a liquid crystal display panel, but embodiments of the inventive concept are not limited thereto, and various other light-receiving display panels can be applied as the display panel <NUM>.

The display panel <NUM> may include a first substrate <NUM>, a second substrate <NUM> facing the first substrate <NUM>, and a liquid crystal layer disposed between the first substrate <NUM> and the second substrate <NUM>. The first substrate <NUM> and the second substrate <NUM> overlap each other. In an exemplary embodiment, any one of the first and second substrates <NUM> and <NUM> may be larger than the other substrate and protrude further outward than the other substrate. <FIG> shows that the second substrate <NUM> disposed on the first substrate <NUM> is larger and protrudes on a side where the light source <NUM> is disposed. The protruding area of the second substrate <NUM> may provide a space in which a driving chip or an external circuit board is mounted. Unlike in the above example, the first substrate <NUM> disposed under the second substrate <NUM> may be greater in size than the second substrate <NUM> and may protrude outward. An overlapping area of the first substrate <NUM> and the second substrate <NUM> excluding the protruding area in the display panel <NUM> may be substantially aligned with side surfaces <NUM> of the light guide plate <NUM> of the optical member <NUM>.

The optical member <NUM> may be coupled to the display panel <NUM> by an inter-module coupling member <NUM>. The inter-module coupling member <NUM> may be shaped like a quadrilateral frame in plan view. The inter-module coupling member <NUM> may be located at edge portions of the display panel <NUM> and the optical member <NUM>.

In an exemplary embodiment, a lower surface of the inter-module coupling member <NUM> is disposed on an upper surface of a wavelength conversion overlying layer <NUM> of the optical member <NUM>. The lower surface of the inter-module coupling member <NUM> may be disposed on the wavelength conversion overlying layer <NUM> to overlap only an upper surface of the wavelength conversion layer <NUM> and not overlap side surfaces of the wavelength conversion layer <NUM>.

The inter-module coupling member <NUM> may include a polymer resin or an adhesive or sticky tape.

In an exemplary embodiment, the inter-module coupling member <NUM> may further perform a light transmission blocking function. For example, the inter-module coupling member <NUM> may include a light absorbing material, such as a black pigment or a dye, or may include a reflective material to perform the light transmission blocking function.

The display <NUM> may further include the housing <NUM>. The housing <NUM> has an open surface, and includes a bottom surface <NUM> and sidewalls <NUM> connected to the bottom surface <NUM>. The light source <NUM>, the optical member <NUM>, and the display panel <NUM> attached to each other, and the reflective member <NUM> may be accommodated in a space defined by the bottom surface <NUM> and the sidewalls <NUM>. The light source <NUM>, the reflective member <NUM>, and the optical member <NUM>, and the display panel <NUM> attached to each other are disposed on the bottom surface <NUM> of the housing <NUM>. The height of the sidewalls <NUM> of the housing <NUM> may be substantially the same as the height of the optical member <NUM> and the display panel <NUM> attached to each other inside the housing <NUM>. The display panel <NUM> may be disposed adjacent to an upper end of each sidewall <NUM> of the housing <NUM> and may be coupled to the upper end of each sidewall <NUM> of the housing <NUM> by a housing coupling member <NUM>. The housing coupling member <NUM> may be shaped like a quadrilateral frame in plain view. The housing coupling member <NUM> may include a polymer resin or an adhesive or sticky tape.

The display <NUM> may further include at least one optical film <NUM>. One or more optical films <NUM> may be accommodated in a space surrounded by the inter-module coupling member <NUM> between the optical member <NUM> and the display panel <NUM>. Side surfaces of one or more optical films <NUM> may be in contact with and attached to inner side surfaces of the inter-module coupling members <NUM>. Although <FIG> shows that there is a gap between the optical film <NUM> and the optical member <NUM>, and between the optical film <NUM> and the display panel <NUM>, the gap is not necessarily required and may be omitted.

The optical film <NUM> may be a prism film, a diffusion film, a micro-lens film, a lenticular film, a polarizing film, a reflective polarizing film, or a retardation film. The display1000 may include a plurality of optical films <NUM> of the same type or different types. When a plurality of optical films <NUM> are applied, the optical films <NUM> may be placed to overlap each other, and side surfaces of the optical films <NUM> may be in contact with and attached to the inner side surfaces of the inter-module coupling member <NUM>. The optical films <NUM> may be separated from each other, and an air layer may be disposed between the optical films <NUM>.

In the display <NUM> according to the exemplary embodiment of <FIG>, the optical member <NUM> and the display panel <NUM> and, further, the optical film <NUM> are integrated with each other by the inter-module coupling member <NUM>, and the display panel <NUM> and the housing <NUM> are coupled to each other by the housing coupling member <NUM>. Therefore, even if a mold frame is omitted, stable coupling of various members is possible, thus reducing the weight of the display <NUM>. In addition, since the light guide plate <NUM> and the wavelength conversion layer <NUM> are integrated with each other, the thickness of the display <NUM> can be reduced. Furthermore, since side surfaces of the display panel <NUM> are coupled to the sidewalls <NUM> of the housing <NUM> by the housing coupling member <NUM>, a bezel space on the display screen side can be eliminated or minimized.

Referring to <FIG>, the display <NUM> includes a light source <NUM>, an optical member 100_1 disposed on an emission path of the light source <NUM>, and a display panel <NUM> disposed above the optical member 100_1. Unlike the display <NUM> of <FIG>, the display <NUM> illustrated in <FIG> includes the optical member 100_1, in which a wavelength conversion overlying layer 60_1 covers upper and side surfaces of a wavelength conversion layer 50_1, and side surfaces of a wavelength conversion underlying layer 70_1.

The wavelength conversion layer 50_1, particularly wavelength conversion particles included in the wavelength conversion layer 50_1, is vulnerable to moisture/oxygen. In the case of a wavelength conversion film, a barrier film is laminated on upper and lower surfaces of a wavelength conversion layer to prevent the penetration of moisture/oxygen into the wavelength conversion layer. In the illustrated exemplary embodiment, however, since the wavelength conversion layer 50_1 is directly disposed without a barrier film, a sealing structure for protecting the wavelength conversion layer 50_1 is required. The sealing structure may be realized by the wavelength conversion overlying layer 60_1 and a light guide plate 10_1.

The gates through which moisture can penetrate into the wavelength conversion layer 50_1 are the upper surface, the side surfaces, and a lower surface of the wavelength conversion layer 50_1. As described above, since the upper surface and the side surfaces of the wavelength conversion layer 50_1 are covered and protected by the wavelength conversion overlying layer 60_1, the penetration of moisture/oxygen can be blocked or at least reduced.

On the other hand, the lower surface of the wavelength conversion layer 50_1 is in contact with an upper surface of the wavelength conversion underlying layer 70_1. If the wavelength conversion underlying layer 70_1 includes voids VD or is made of an organic material, the movement of moisture in the wavelength conversion underlying layer 70_1 is possible. Therefore, moisture/oxygen can be introduced into the lower surface of the wavelength conversion layer 50_1 through the wavelength conversion underlying layer 70_1. However, since the wavelength conversion underlying layer 70_1 according to an exemplary embodiment also has a sealing structure, penetration of moisture/oxygen through the lower surface of the wavelength conversion layer 50_1 can be blocked at source.

Specifically, since the side surfaces of the wavelength conversion underlying layer 70_1 are covered and protected by the wavelength conversion overlying layer 60_1, penetration of moisture/oxygen through the side surfaces of the wavelength conversion underlying layer 70_1 can be blocked/reduced. Even if the wavelength conversion underlying layer 70_1 protrudes further than the wavelength conversion layer 50_1, such that a portion of the upper surface is exposed, since the exposed portion is covered and protected by the wavelength conversion overlying layer 60_1, penetration of moisture/oxygen through the exposed portion can be blocked/reduced. A lower surface of the wavelength conversion underlying layer 70_1 is in contact with the light guide plate 10_1. When the light guide plate 10_1 is made of an inorganic material such as glass, it can block/reduce the penetration of moisture/oxygen, like the wavelength conversion overlying layer 60_1. That is, since the surfaces of a laminate of the wavelength conversion underlying layer 70_1 and the wavelength conversion layer 50_1 are surrounded and sealed by the wavelength conversion overlying layer 60_1 and the light guide plate 10_1, even if a moisture/oxygen movement path is formed inside the wavelength conversion underlying layer 70_1, penetration of moisture/oxygen can be blocked/reduced by the above sealing structure. Therefore, deterioration of the wavelength conversion particles due to moisture/oxygen can be prevented or at least mitigated.

An optical member according to an exemplary embodiment can simultaneously perform a light guide function and a wavelength conversion function while improving light transmission efficiency through a laminated structure of materials having different refractive indices. The optical member according to an exemplary embodiment is relatively thin and can improve the optical characteristics of a display by maximizing the light transmission efficiency.

Claim 1:
An optical member (<NUM>) comprising:
a light guide plate (<NUM>);
a low refractive layer (<NUM>) disposed on the light guide plate (<NUM>) and having a refractive index less than that of the light guide plate (<NUM>);
a wavelength conversion layer (<NUM>) disposed on the low refractive layer (<NUM>);
wherein the optical member further comprises a low refractive underlying layer (<NUM>) disposed between the low refractive layer (<NUM>) and the light guide plate (<NUM>); and a low refractive overlying layer (<NUM>) disposed between the low refractive layer (<NUM>) and the wavelength conversion layer (<NUM>),
wherein a difference in refractive index between the light guide plate (<NUM>) and the low refractive layer (<NUM>) is <NUM> or more,
wherein a refractive index of the low refractive layer (<NUM>) is <NUM> to <NUM>,
wherein a thickness of the low refractive layer (<NUM>) is <NUM> to <NUM>, and
wherein the low refractive underlying layer (<NUM>) is formed directly on an upper side of the light guide plate (<NUM>) to contact the upper side of the light guide plate (<NUM>) .