Patent Description:
Various display devices used for multimedia devices such as televisions, mobile phones, tablet computers, and game consoles are being developed. The display device may include different types of wavelength control layers according to pixels to generate a color image. The wavelength control layer may transmit a portion of the wavelength range of the source light or convert the wavelength range of the source light.

Such a display device may include various optical functional layers to provide users with improved quality color images, and research is being conducted to reduce external light reflectance.

A display device comprising a display panel, a wavelength control layer disposed on the display panel, a light control member disposed on the wavelength control layer, a color filter, and a cover layer disposed on the light control member is known from <CIT>.

<CIT> describes a display device comprising a display panel, a wavelength control layer, a light control member and a cover layer; the light control member comprising an inorganic layer having a first refractive index, a first light control layer having a second refractive index, a second light control layer having a third refractive index; and a color filter layer with the first and third refractive indices being greater than the second refractive index.

The disclosure provides a display device having a reduced external light reflectance.

An embodiment of the invention provides a display device including: a display panel; a wavelength control layer disposed on the display panel; a light control member disposed on the wavelength control layer; and a cover layer disposed on the light control member, where the light control member includes: an inorganic layer disposed on the wavelength control layer and having a first refractive index; a first light control layer disposed on the inorganic layer and having a second refractive index; a second light control layer disposed on the first light control layer and having a third refractive index; and a color filter layer disposed on the second light control layer. In such an inventive embodiment, the first refractive index is greater than the second refractive index and is less than a refractive index of the wavelength control layer, and the third refractive index is greater than the second refractive index and is less than a refractive index of the color filter layer.

In an embodiment, each of the first refractive index and the third refractive index may be in a range of about <NUM> to about <NUM>.

In an embodiment, a thickness of the inorganic layer may be in a range of about <NUM> kiloangstrom (kÅ) (<NUM>) to about <NUM> kÅ (<NUM>).

In an embodiment, a thickness of the second light control layer may be in a range of about <NUM> kÅ (<NUM>) to about <NUM> kÅ (<NUM>) or in a range of about <NUM> kÅ to about <NUM> kÅ.

In an embodiment, the second light control layer may include an inorganic film or an organic film.

In an embodiment, the second light control layer may include an optically transparent organic film.

In an embodiment, the second light control layer may include an organic film, in which a light transmittance in a yellow light wavelength range is less than a light transmittance in a blue light wavelength range.

In an embodiment, the second refractive index may be about <NUM> or less.

In an embodiment, the display panel may include a pixel area and a peripheral area adjacent to the pixel area, and the display panel may include a light emitting element which generates first light and is disposed in the pixel area. In such an embodiment, the wavelength control layer may include: a partition part in which a plurality of opening parts are defined; a first wavelength control unit disposed in one of the opening parts, where the first wavelength control unit may convert the first light into a second light; and a second wavelength control unit disposed in another of the opening parts, where the second wavelength control unit may convert the first light to a third light. In such an embodiment, the color filter layer may include: a first color filter part overlapping the first wavelength control unit, where the first color filter part may transmit the second light; and a second color filter part overlapping the second wavelength control unit, where the second color filter part may transmit the third light.

In an embodiment, a portion of the first color filter part and a portion of the second color filter part may overlap the partition part.

In an embodiment, the wavelength control layer may further include a transmission part disposed in an opening part, in which the first wavelength control unit and the second wavelength control unit are not disposed among the opening parts, where the transmission part may transmit the first light.

In an embodiment, the second light control layer may overlap the transmission part, where a portion of the second light control layer overlapping the transmission part may directly contact the cover layer.

In an embodiment, the first wavelength control unit and the second wavelength control unit may include a quantum dot, where the transmission part may include a scatterer.

In an embodiment, the transmission part may further include a colorant which transmits the first light and absorbs the second light and the third light.

In an embodiment, a thickness of the transmission part may be greater than a thickness of the first wavelength control unit and a thickness of the second wavelength control unit.

In an embodiment, the light emitting element may be an organic light emitting diode element, a micro light emitting diode element or a nano light emitting diode element.

In an embodiment of the invention, a display device includes: a light emitting element layer which outputs a first light; a wavelength control layer disposed on the light emitting element layer; and a light control member disposed on the wavelength control layer, where the light control member includes: an inorganic layer disposed on the wavelength control layer and having a first refractive index; a first light control layer disposed on the inorganic layer and having a second refractive index; and a color filter layer disposed on the first light control layer, wherein the first refractive index is greater than the second refractive index of the wavelength control layer and is less than a refractive index of the wavelength control layer and a thickness of the inorganic layer is in a range of about <NUM> kÅ (<NUM>) to about <NUM> kÅ (<NUM>).

In an embodiment, the light control member may further include a second light control layer between the first light control layer and the color filter layer, where each of a refractive index of the inorganic layer and a refractive index of the second light control layer may be in a range of about <NUM> to about <NUM>.

In an embodiment, a thickness of the second light control layer may be in a range of about <NUM> kÅ (<NUM>) to about <NUM> kÅ (<NUM>) or in a range of about <NUM> kÅ (<NUM>) to about <NUM> kÅ (<NUM>).

In an embodiment, the wavelength control layer may include: a first wavelength control unit including a first quantum dot which converts the first light into red light; a second wavelength control unit including a second quantum dot which converts the first light into green light; and a transmission part including a blue colorant and a scatterer. In such an embodiment, the color filter layer may include: a first color filter part overlapping the first wavelength control unit, where the first color filter part may transmit the red light; and a second color filter part overlapping the second wavelength control unit, where the second color filter part may transmit the green light.

The above and other features of the invention will become more apparent by describing in further detail embodiments thereof with reference to the accompanying drawings, in which:.

The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments are shown. This invention may, however, be embodied in many different forms, and should not be construed as limited to the embodiments set forth herein. The invention is defined in claim <NUM> or claim <NUM>. Preferred embodiments are defined in dependent claims <NUM> to <NUM>. In the drawings, the thicknesses, proportions, and dimensions of components are exaggerated for effective description.

In this specification, when it is mentioned that a component (or, an area, a layer, a part, etc.) is referred to as being "on", "connected to" or "combined to" another component, this means that the component may be directly on, connected to, or combined to the other component or a third component therebetween may be present therebetween. In contrast, when an element is referred to as being "directly on", "connected directly to" or "combined directly to" another element, there are no intervening elements present.

It will be understood that the terms "first" and "second" are used herein to describe various components but these components should not be limited by these terms. The above terms are used only to distinguish one component from another. For example, a first component may be referred to as a second component and vice versa without departing from the scope of the invention. The terms of a singular form may include plural forms unless otherwise specified.

The term "lower," can therefore, encompass both an orientation of "lower" and "upper," depending on the particular orientation of the figure.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as terms commonly understood by those skilled in the art to which this invention belongs. In general, the terms defined in the dictionary should be considered to have the same meaning as the contextual meaning of the related art, and, unless clearly defined herein, should not be understood abnormally or as having an excessively formal meaning.

Embodiments are described herein with reference to cross section illustrations that are schematic illustrations of embodiments.

Hereinafter, embodiments of a display device will be described in detail with reference to the accompanying drawings.

<FIG> is a perspective view of a display device.

In <FIG>, the display device DD may be a portable electronic device. Alternatively, the display device DD may be a medium-sized electronic device such as personal computers, notebook computers, personal digital assistants, car navigation units, game machines, smart phones, tablets and cameras, or a large-sized electronic device such as televisions, monitors, or external billboards. However, embodiments of the display device DD are not limited to those listed above, but the display device DD may be another electronic device.

An embodiment of the display device DD may have a hexahedral shape having a thickness in the third direction DR3 on a plane defined by a first direction DR1 and a second direction DR2 intersecting each other, but not being limited thereto. Alternatively, the display device DD may have one of various shapes.

Herein, the upper surface (or front surface) and the lower surface (or back surface) of each member is defined based on the direction in which the image IM is displayed. The upper surface and the lower surface may be opposite to each other in the third direction DR3, and the normal directions of the upper surface and the lower surface may be parallel to the third direction DR3 and a fourth direction DR4. Here, the fourth direction DR4 is a direction opposite to the third direction DR3.

Herein, the directions indicated by the first to fourth directions DR1, DR2, DR3, and DR4 are relative concepts and may be converted to other directions. Hereinafter, the first to fourth directions refer to the same reference numerals in the directions indicated by the first to fourth directions DR1, DR2, DR3, and DR4, respectively.

The display device DD may display the image IM through a display surface IS. The display surface IS includes a display area DA for displaying the image IM and a non-display area NDA adjacent to the display area DA. The non-display area NDA is an area on which no image is displayed. The image IM may be a dynamic image or a static image. In an embodiment, as shown in <FIG>, the image IM may include a plurality of application icons and a clock.

The display area DA may be in a rectangular shape. The non-display area NDA may surround the display area DA. However, the invention is not limited thereto, and a form of the display area DA and a form of the non-display area NDA may be variously modified. In an embodiment, the non-display area NDA on a front surface of the display device DD may be omitted.

In an embodiment, the display device DD may be flexible. In such an embodiment, the display device DD may have a property that allows the display device DD to be bent, which includes a fully folded structure to a structure that may be bent at a level of several nanometers. In one embodiment, for example, the display device DD may be a curved display device or a foldable display device. However, the display device DD is not limited thereto, and alternatively, the display device DD may be rigid.

<FIG> is an exploded perspective view of a display device.

Referring to <FIG>, an embodiment of the display device DD includes a display panel DP, a wavelength control layer WCL, a light control member LP, and a cover layer CV sequentially arranged along the third direction DR3.

The display panel DP may include a plurality of pixels PX in an area corresponding to the display area DA of the display device DD. The plurality of pixels PX may be arranged to be spaced apart from each other in the display area DA. The pixels PX may display an image IM on the display area DA by outputting light having color information based on an electrical signal. The plurality of pixels PX may correspond to a pixel area PXA (see <FIG>).

The display panel DP may be a light emitting display panel. For example, the display panel DP may be an organic light emitting display panel, a quantum dot light emitting display panel, a micro light emitting diode ("LED") display panel, or a nano LED display panel. The light emitting layer of the organic light emitting display panel may include an organic light emitting material. The light emitting layer of the quantum dot light emitting display panel may include a quantum dot and/or a quantum rod. The micro LED display panel may include a micro LED element, which is an ultra-small light emitting element, and the nano LED display panel may include a nano LED element.

The wavelength control layer WCL is disposed on the display panel DP. The wavelength control layer WCL transmits light outputted from the display panel DP or converts the light from the display panel DP into light having a different wavelength to output various color lights.

The light control member LP is disposed on the wavelength control layer WCL. The light control member LP may increase light conversion efficiency by reflecting light transmitted through the wavelength control layer WCL back to the wavelength control layer WCL. The light control member LP may improve the visibility of the light provided by the wavelength control layer WCL by reducing the reflectance of light incident from the outside to the display device DD.

The cover layer CV is disposed on the light control member LP. The cover layer CV may protect components disposed under the cover layer CV from external factors. The cover layer CV may include glass.

<FIG> is an enlarged view of a portion of the display area DA shown in <FIG>. The display area DA may include a pixel area PXA and a peripheral area NPXA adjacent to the pixel area PXA.

For convenience of illustration and description, <FIG> mainly shows three types of pixel areas PXA1, PXA2, and PXA3. The three types of pixel areas PXA1, PXA2, and PXA3 shown in <FIG> may be repeatedly disposed in the entire display area DA. The peripheral area NPXA may set a boundary between the first to third pixel areas PXA1, PXA2, and PXA3 to prevent color mixing between the first to third pixel areas PXA1, PXA2, and PXA3.

In <FIG>, the first to third pixel areas PXA1, PXA2, and PXA3 may have a same planar area as each other, but are not limited thereto. Alternatively, the first to third pixel areas PXA1, PXA2, and PXA3 may have different areas from each other, or only one or two of the first to third pixel areas PXA1, PXA2, and PXA3 may have different areas from another. The shapes of the first to third pixel areas PXA1, PXA2, and PXA3 are not limited to the illustrated rectangular shape and may have another shape such as a polygonal shape.

One of the first to third pixel areas PXA1, PXA2, and PXA3 provides a first light to the user, another provides a second light different from the first light, and the remaining one provides a third light different from the first light and the second light. In one embodiment, for example, the first pixel area PXA1 provides red light, the second pixel area PXA2 provides green light, and the third pixel area PXA3 provides blue light.

Each of the first to third pixel areas PXA1, PXA2, and PXA3 may correspond to the pixel PX (see <FIG>). The first to third pixel areas PXA1, PXA2, and PXA3 may provide or emit different color light from each other based on an electrical signal applied thereto. Accordingly, the plurality of pixels PX corresponding to the first to third pixel areas PXA1, PXA2, and PXA3 may output light having color information.

<FIG> are cross-sectional views taken along line I-I' of <FIG> of a display device. Each of embodiments of the display device DD illustrated in <FIG> includes a display panel DP, a cover layer CV, a light control member LP-a and LP-b, and a wavelength control layer WCL. The embodiments of the display device DD illustrated in <FIG> have substantially the same configuration as each other except for the wavelength control layer WCL and the light control members LP-a and LP-b. Hereinafter, a non inventive display device will be described with reference to <FIG> and embodiments of the invention will be described with reference to <FIG>.

The display panel DP may include a base layer BL, a circuit layer DP-CL, and a light emitting element layer DP-EDL sequentially stacked along the third direction DR3. Pixel areas PXA1, PXA2, and PXA3 and a peripheral area NPXA adjacent to the pixel areas PXA1, PXA2, and PXA3 may be defined in the display panel DP. In <FIG>, three types of pixel areas, i.e., first to third pixel areas PXA1, PXA2, and PXA3 are shown.

The base layer BL included in the display panel DP may be rigid or flexible. The base layer BL may be a polymer substrate, a plastic substrate, a glass substrate, a metal substrate, or a composite material substrate. In one embodiment, for example, the base layer BL may be a flexible substrate including a polyimide resin. However, the material included in the base layer BL is not limited to those described above.

The circuit layer DP-CL may be disposed on the base layer BL. The circuit layer DP-CL may include a plurality of transistors (not shown). Each of the transistors (not shown) may include a control electrode, an input electrode, and an output electrode. In one embodiment, for example, the circuit layer DP-CL may include a switching transistor and a driving transistor for driving a light emitting element EDL.

The light emitting element layer DP-EDL may be disposed on the circuit layer DP-CL. The light emitting element layer DP-EDL may include a pixel defining film PDL, the light emitting element EDL, and an encapsulation layer TFE. The light emitting element layer DP-EDL may display an image by emitting light corresponding to an electrical signal transmitted through a plurality of transistors (not shown) included in the circuit layer DP-CL.

The light emitting element EDL may be disposed in the pixel areas PXA1, PXA2, and PXA3. The light emitting element EDL may include a first electrode EL1, a second electrode EL2, and a light emitting layer EML. The first electrode EL1 and the second electrode EL2 may be disposed opposite to each other. The light emitting layer EML may be disposed between the first electrode EL1 and the second electrode EL2.

The light emitting element EDL may generate light by activating the light emitting layer EML based on a potential difference between the first electrode EL1 and the second electrode EL2. The light emitting element EDL may be an organic light emitting diode ("OLED") element, a micro LED element, or a nano LED element.

The light emitting layer EML may include an organic light emitting material, an inorganic light emitting material, and the like, and may include a micro-scale or nano-scale light-emitting body or unit. The light emitting element EDL may generate first light by recombining holes and electrons injected from the first electrode EL1 and the second electrode EL2 in the light emitting layer EML.

The first light may be blue light. The blue light may be light in a wavelength range of about <NUM> nanometers (nm) to about <NUM>, but is not limited thereto, and may be in a wavelength range recognized as a blue color. However, the first light is not limited to the blue light, but the first light may be designed as light of one of various colors.

Although not shown in the drawings, the light emitting element EDL may further include a hole transport area and an electron transport area. The hole transport area may be disposed between the light emitting layer EML and the first electrode EL1, and the electron transport area may be disposed between the light emitting layer EML and the second electrode EL2. The hole transport area may transport holes injected from the first electrode EL1 to the light emitting layer EML. The electron transport area transports electrons injected from the second electrode EL2 to the light emitting layer EML. Each of the light emitting layer EML, the electron transport area, and the hole transport area may also be provided in plurality, but not being limited thereto.

The pixel defining film PDL may be disposed on the circuit layer DP-CL. Predetermined opening parts may be defined in the pixel defining film PDL. The opening parts defined in the pixel defining film PDL may correspond to pixel areas PXA1, PXA2, and PXA3, respectively. The pixel defining film PDL may correspond to the peripheral area NPXA.

The pixel defining film PDL may include an organic resin or an inorganic material. In one embodiment, for example, the pixel defining film PDL may include or be formed of a polyacrylate-based resin, a polyimide-based resin, silicon nitride (SiNx), silicon oxide (SiOx), or silicon oxynitride (SiOxNy).

The encapsulation layer TFE may be disposed on the light emitting element EDL to seal the light emitting element EDL. The encapsulation layer TFE may protect the light emitting element EDL from moisture/oxygen and protect the light emitting element EDL from foreign substances such as dust particles.

The encapsulation layer TFE may include an organic film or an inorganic film. In one embodiment, for example, the encapsulation layer TFE may include an organic film and an inorganic film. The encapsulation layer TFE may have a structure in which the organic film OL and the inorganic films IL1 and IL2 are alternately stacked one on another.

The inorganic film IL1 and IL2 included in the encapsulation layer TFE may include, for example, a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminium oxide layer, but not being limited thereto. The organic film OL included in the encapsulation layer TFE may include an acrylic-based organic film, but not being limited thereto.

The display device DD may include the cover layer CV, the light control member LP-a and LP-b, the wavelength control layer WCL, and a capping layer CP disposed on the display panel DP. The cover layer CV, the light control member LP-a and LP-b, the wavelength control layer WCL and the capping layer CP may be sequentially disposed on the display panel DP in the fourth direction DR4.

The cover layer CV isdisposed on the display panel DP. The cover layer CV may protect components disposed below. The cover layer CV serves as a substrate for forming the light control member LP-a and LP-b and the wavelength control layer WCL, which is disposed between the cover layer CV and the display panel DP. The cover layer CV may include glass.

The light control members LP-a and LP-b may be disposed on the cover layer CV in the fourth direction DR4. The light control members LP-a and LP-b may reduce the external light reflectance of the display device DD and improve the light output efficiency. Each of the light control members LP-a and LP-b may include a color filter layer CFL, a light control layer LL1 or LL2, and an inorganic layer IO.

The color filter layer CFL is disposed on the cover layer CV in the fourth direction DR4. The color filter layer CFL may be disposed directly on the cover layer CV. The color filter layer CFL may have a patterned structure formed on the cover layer CV. The color filter layer CFL may reduce reflection of external light and prevent color mixing. The color filter layer CFL may include a first color filter part CF1 and a second color filter part CF2. Each of the color filter parts CF1 and CF2 may transmit light only in a specific wavelength range and absorb light in the remaining wavelength range.

The second color filter part CF2 may be disposed on the cover layer CV in the fourth direction DR4. The front surface of the second color filter part CF2 may directly contact the cover layer CV. The second color filter part CF2 may be formed on a portion of the cover layer CV. The second color filter part CF2 may be arranged to overlap some pixel areas among the plurality of pixel areas. Referring to <FIG>, the second color filter part CF2 may overlap the second pixel area PXA2. A portion of the second color filter part CF2 may overlap the peripheral area NPXA.

The second color filter part CF2 may transmit third light having a wavelength range different from that of the first light provided by the light emitting element EDL, and block the first light and the second light. For example, the third light may be green light. The green light may be light in a wavelength range of about <NUM> to about <NUM>, but is not limited thereto, and may include a wavelength range recognized as a green color. The second color filter part CF2 may include a green pigment or a green dye.

The first color filter part CF1 may be disposed on the cover layer CV in the fourth direction DR4. A portion of the first color filter part CF1 may be in direct contact with the cover layer CV, and another portion may be in contact with a portion of the second color filter part CF2. The first color filter part CF1 may be formed in a portion of the cover layer CV on which the second color filter part CF2 is formed. The first color filter part CF1 may be arranged to overlap some pixel areas among the plurality of pixel areas. Referring to <FIG>, the first color filter part CF1 may overlap the first pixel area PXA1 that is non-overlapping with the second color filter part CF2. A portion of the first color filter part CF1 may overlap the peripheral area NPXA.

The first color filter part CF1 may transmit second light having a wavelength range different from the first light provided by the light emitting element EDL, and may block the first light and the third light. For example, the second light may be red light. The red light may be light having a wavelength range of about <NUM> to about <NUM>, but is not limited thereto, and may include a wavelength range recognized as a red color. The first color filter part CF1 may include a red pigment or a red dye.

A portion of the first color filter part CF1 and a portion of the second color filter part CF2 may be disposed to overlap the peripheral area NPXA. A portion of the first color filter part CF1 overlaps the peripheral area NPXA to cover a portion of the lower surface of the second color filter part CF2. The first color filter part CF1 may block the first light and the third light, and the second color filter part CF2 may block the first light and the second light. Therefore, the overlapping portion of the first color filter part CF1 and the second color filter part CF2 may serve as a light blocking layer and effectively prevent light leakage.

Although not illustrated in the drawing, the color filter layer CFL may further include a light blocking part including a light blocking material. The light blocking part may be disposed to overlap the peripheral area NPXA. The plurality of color filter parts may be spaced apart from each other with an adjacent light blocking part interposed therebetween. Therefore, the light blocking part may be a boundary between color filter parts.

A color filter layer CFL may not be disposed on some areas of the cover layer CV. The color filter layer CFL may not be placed in an area overlapping some pixel areas among the plurality of pixel areas. Referring to <FIG>, a color filter part (e.g., CF1 or CF2) is not disposed in an area overlapping the third pixel area PXA3. Therefore, the first color filter part CF1 and the second color filter part CF2 may not overlap the third pixel area PXA3 in the third direction DR3.

The light control layer LL1 or LL2 is disposed on the color filter layer CFL in the fourth direction DR4. According to an embodiment of the light control member, a single light control layer may be included, or a plurality of light control layers having different refractive indices from each other may be included. <FIG> shows an embodiment where a light control member LP-a includes a single light control layer, e.g., a first light control layer LL1, and <FIG> shows a display device where a light control member LP-b includes a plurality of light control layers, e.g., a first light control layer LL1 and a second light control layer LL2.

The first light control layer LL1 is disposed on the color filter layer CFL in the fourth direction DR4, and referring to <FIG>, may be directly disposed on the lower surface of the color filter layer CFL. The first light control layer LL1 may be disposed on the cover layer CV where the first color filter part CF1 and the second color filter part CF2 are disposed to cover the lower surface of the first color filter part CF1 and the second color filter part CF2. In the area where the color filter part is not disposed, the first light control layer LL1 may directly contact the cover layer CV.

The first light control layer LL1 may have a relatively low refractive index compared to other stacked structures. For example, the refractive index of the first light control layer LL1 may be about <NUM> or less. For example, the refractive index of the first light control layer LL1 may about <NUM> or less in the wavelength range of visible light. The first light control layer LL1 may reflect the light provided through the display panel DP at a wider angle using a difference in refractive index and improve a viewing angle.

The wavelength control layer WCL is disposed below the first light control layer LL1. The wavelength control layer WCL may convert light provided by the display panel DP into light in a different wavelength range and provide light of various colors. The first light control layer LL1 may increase the wavelength conversion efficiency of light by reflecting light having no wavelength conversion back to the wavelength control layer WCL using a difference in refractive index.

The first light control layer LL1 may include an organic film, and may further include inorganic particles included in the organic film. In one embodiment, for example, the organic film may include acrylic, polysiloxane, polyurethane, polyimide or the like, and the inorganic particles may include silica or the like, but not being limited thereto.

The inorganic layer IO is disposed on the first light control layer LL1 in the fourth direction DR4. The inorganic layer IO may be directly disposed on the first light control layer LL1 and may cover the lower surface of the first light control layer LL1. The wavelength control layer WCL is disposed under the inorganic layer IO.

A refractive index of the inorganic layer IO (n1) is less than a refractive index of the wavelength control layer WCL (nWCL), and is greater than a refractive index of the first light control layer LL1 (n2). The inorganic layer IO may reduce the difference between the refractive index of the first light control layer LL1 and the refractive index of the wavelength control layer WCL, thereby reducing the amount of light reflected and reducing external light reflection. In one embodiment, for example, the refractive index of the inorganic layer IO may be in a range of about <NUM> to about <NUM>. For example, the refractive index of the inorganic layer IO may be in a range of about <NUM> to about <NUM> in the wavelength range of visible light.

The inorganic layer IO may include an inorganic material satisfying the refractive index relationship described above. In one embodiment, for example, the inorganic layer IO may include silicon oxide (SiOx), but is not limited thereto.

The inorganic layer IO may have a specific thickness to reduce light reflectance in a specific wavelength range. The reflectance of light irradiated to the inorganic layer IO may be repeatedly increased and decreased depending on the wavelength. The wavelength range in which the reflectance is reduced may vary depending on the thickness of the inorganic layer IO. Therefore, the light reflectance in the visible light region may be reduced by adjusting the thickness of the inorganic layer IO. In an inventive embodiment,the relation between the refractive indices is n2<n1<nWCL and the thickness of the inorganic layer IO is in a range of about <NUM> kiloangstrom (kÅ) to about <NUM> kÅ (i.e. about <NUM> to about <NUM>).

Referring to <FIG>, in an alternative embodiment, the light control member LP-b further includes a second light control layer LL2. The second light control layer LL2 is disposed between the color filter layer CFL and the first light control layer LL1. Accordingly, the second light control layer LL2 may be disposed directly on the lower surface of the color filter layer CFL, and the first light control layer LL1 may be directly disposed directly on the lower surface of the second light control layer LL2. In the area where the color filter part is not disposed, the second light control layer LL2 may directly contact the cover layer CV. The second light control layer LL2 may be disposed or formed on the cover layer CV where the first color filter part CF1 and the second color filter part CF2 are disposed to cover the lower surface of the first color filter part CF1 and the second color filter part CF2.

The external light visibility of the display device DD may be improved by adjusting the refractive index or thickness of the second light control layer LL2. In an inventive embodiment, the relation between refractive indices n2<n1<nWCL holds and the refractive index of the second light control layer LL2 is less than the refractive index of the color filter layer CFL, and is greater than the refractive index of the first light control layer LL1. The second light control layer LL2 may reduce the difference between the refractive index of the first light control layer LL1 and the refractive index of the color filter layer CFL, thereby reducing the amount of light reflected and reducing external light reflection. In one embodiment, for example, the refractive index of the second light control layer LL2 may be in a range of about <NUM> to about <NUM>. For example, the refractive index of the second light control layer LL2 may be in a range of about <NUM> to about <NUM> in the wavelength range of visible light.

The second light control layer LL2 may include an inorganic film satisfying the refractive index relationship described above. In one embodiment, for example, the inorganic film may be a silicon oxide (SiOx) inorganic film. However, the material of the inorganic film is not limited thereto.

The second light control layer LL2 may include an organic film satisfying the refractive index relationship described above. The second light control layer LL2 may include an optically transparent organic film.

The organic film included in the second light control layer LL2 may have a light transmittance in the yellow light wavelength range, which is less than a light transmittance in the blue light wavelength range. For example, the organic film included in the second light control layer LL2 may have a light transmittance in the wavelength range of about <NUM> to about <NUM>, which is lower than the light transmittance in the wavelength range of about <NUM> to about <NUM>. However, the wavelength range is not limited thereto, and the yellow light wavelength range and the blue light wavelength range may include a wavelength range recognized as yellow and blue, respectively.

For example, the light transmittance of the second light control layer LL2 may have a same trend as the graph illustrated in <FIG> and will be described later in detail with reference to <FIG>. When the second light control layer LL2 includes the above-described organic film, the external light reflectance of the display device DD may be more effectively reduced.

By controlling the thickness of the second light control layer LL2, the effect of reducing external light reflectance may be improved. The light reflected at the interface between the color filter layer CFL and the second light control layer LL2 and the light reflected at the interface between the inorganic layer IO and the wavelength control layer WCL may be destructively inteferenced, and the degree of destructive interference may vary depending on the thickness of the second light control layer LL2 and the inorganic layer IO. In a display device, where the second light control layer LL2 includes an inorganic film, the external light reflectance effect according to the thickness control may be greater. For example, the thickness of the second light control layer LL2 may be in a range of about <NUM> kÅ (<NUM>) to about <NUM> kÅ (<NUM>) or in a range of about <NUM> kÅ (<NUM>) to about <NUM> kÅ (<NUM>).

Referring to <FIG>, the wavelength control layer WCL is disposed in the fourth direction DR4 on the inorganic layer IO. The wavelength control layer WCL can be in direct contact with the inorganic layer IO, thereby protecting the upper surface of the wavelength control layer WCL from moisture, oxygen or foreign matter.

The wavelength control layer WCL may transmit light provided by the light emitting element EDL or convert light provided by the light emitting element EDL into light having a different wavelength range. The wavelength control layer WCL may provide light having different colors in correspondence with the first to third pixel areas PXA1, PXA2, and PXA3.

The wavelength control layer WCL may include a partition part BK in which a plurality of opening parts are defined, a first wavelength control unit WC1, and a second wavelength control unit WC2. The wavelength control layer WCL may further include a transmission part TP.

The partition part BK may be disposed on the lower surface of the inorganic layer IO. The partition part BK may directly contact the inorganic layer IO. After placing the light control members LP-a and LP-b on the cover layer CV, the partition part BK, in which the plurality of opening parts are defined, may be provided or formed on the light control members LP-a and LP-b. The partition part BK may overlap the peripheral area NPXA. The partition part BK may prevent light leakage and define a boundary between adjacent wavelength control units WC1 and WC2 and the transmission part TP. The partition part BK may include an organic material. The partition part BK may include an organic light blocking material including black pigment or dye.

A portion of the first color filter part CF1 and a portion of the second color filter part CF2 may overlap the partition part BK. A portion of the first color filter part CF1 and a portion of the second color filter part CF2 may be in contact with each other on the partition part BK.

The first wavelength control unit WC1 may be disposed in one of the plurality of opening parts defined in the partition part BK, and the second wavelength control unit WC2 may be disposed in another of the plurality of opening parts. In such an embodiment, the second wavelength control unit WC2 may be disposed in opening parts of the partition part BK in which the first wavelength control unit WC1 is not disposed.

The wavelength control layer WCL may further include a transmission part TP. The transmission part TP may be disposed in one of a plurality of opening parts defined in the partition part BK. The transmission part TP may be disposed in opening parts of the partition part BK in which the first wavelength control unit WC1 and the second wavelength control unit WC2 are not disposed. Accordingly, each of the first wavelength control unit WC1, the second wavelength control unit WC2, and the transmission part TP is spaced apart from each other when viewed on a plane defined by the first direction DR1 and the second direction DR2.

The first wavelength control unit WC1 and the second wavelength control unit WC2 may be disposed under the inorganic layer IO. The first wavelength control unit WC1 and the second wavelength control unit WC2 may be in direct contact with the inorganic layer IO.

The first wavelength control unit WC1 may be arranged to overlap the first pixel area PXA1. The first wavelength control unit WC1 may overlap the first color filter part CF1. The first wavelength control unit WC1 may convert the first light provided by the display panel DP into second light having a different wavelength range. In one embodiment, for example, the second light may be red light. Therefore, the first pixel area PXA1 may provide red light.

The first wavelength control unit WC1 may include a base resin and a quantum dot QD1. The quantum dot QD1 may be dispersed in the base resin included in the first wavelength control unit WC1. The quantum dot QD1 included in the first wavelength control unit WC1 may be particles that convert the first light into second light in a different wavelength range.

The second wavelength control unit WC2 may be arranged to overlap the second pixel area PXA2. The second wavelength control unit WC2 may overlap the second color filter part CF2. The second wavelength control unit WC2 may convert the first light provided by the display panel DP into third light in a different wavelength range. For example, the third light may be green light. Therefore, the second pixel area PXA2 may provide green light.

The second wavelength control unit WC2 may include a base resin and a quantum dot QD2. The quantum dot QD2 may be dispersed within the base resin included in the second wavelength control unit WC2. The quantum dot QD2 included in the second wavelength control unit WC2 may be particles that convert the first light into third light in a different wavelength range.

The quantum dots QD1 and QD2 included in the wavelength control units WC1 and WC2 may be a semiconductor nanocrystal including at least one material selected from group II-VI compounds, group III-VI compounds, group III-V compounds, group IV-VI compounds, group IV elements or compounds, group I-III-VI compounds, and a combination thereof.

The Group II-VI compound may include: binary element compounds selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS and a combination (e.g., a compound) thereof; ternary element compounds selected from CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS and a combination thereof; and quaternary element compounds selected from CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe and a combination thereof.

The group III-VI compound may include a binary element compound such as In<NUM>S<NUM>, In<NUM>Se<NUM>, and the like, a trielement compound such as InGaS<NUM>, InGaSe<NUM>, and the like, or any combination thereof.

The group III-V compound may include: binary element compounds selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb and a combination thereof; ternary element compounds selected from GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InAlP, InNP, InNAs, InNSb, InPAs, InPSb and combination thereof; and quaternary element compounds selected from GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb and combination thereof.

The group III-V semiconductor compound may further include a group II metal such as InZnP.

The Group IV-VI compound may include: binary element compounds selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe and a combination thereof; ternary element compounds selected from SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe and a combination thereof; and quaternary element compounds selected from SnPbSSe, SnPbSeTe, SnPbSTe and a combination thereof. The group IV elements may include Si, Ge and a combination thereof. The IV group compound may include a binary element compound selected from SiC, SiGe and a combination thereof.

The group I-III-VI semiconductor compound may include AgInS, AgInS<NUM>, CuInS, CuInS<NUM>, CuGaO<NUM>, AgGaO<NUM>, AgAlO<NUM>, and the like, or any combination thereof.

The binary element compound, the ternary element compound, or the quaternary element compound may be in the particle at a uniform concentration, or may be in a same particle by dividing the concentration distribution into a partially different state.

The quantum dots QD1 and QD2 may have a core shell structure including a core and a shell surrounding the core. One quantum dot may have a core/shell structure surrounding other quantum dots. In the core-shell structure, a concentration of elements existing in the shell may have a concentration gradient that decreases toward the core.

The shells of the quantum dots QD1 and QD2 may include an oxide of a metal or a nonmetal, semiconductor compound, or a combination thereof.

For example, the metal or nonmetal oxide used in the shell may include a binary element compound such as SiO<NUM>, Al<NUM>O<NUM>, TiO<NUM>, ZnO, MnO, Mn<NUM>O<NUM>, Mn<NUM>O<NUM>, CuO, FeO, Fe<NUM>O<NUM>, Fe<NUM>O<NUM>, CoO, Co<NUM>O<NUM>, NiO, and the like or a ternary element compound such as MgAl<NUM>O<NUM>, CoFe<NUM>O<NUM>, NiFe<NUM>O<NUM>, CoMn<NUM>O<NUM>, and the like.

In addition, the semiconductor compound may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, and the like.

The quantum dots QD1 and QD2 can control the color of emitted light according to the particle size, and thus the quantum dots QD1 and QD2 may have various luminescent colors such as green, red, and the like. As the particle size of the quantum dots QD1 and QD2 becomes smaller, the quantum dots QD1 and QD2 may emit light in the short wavelength region. In one embodiment, for example, the particle size of the quantum dot emitting green light may be smaller than the particle size of the quantum dot emitting red light.

The transmission part TP may be disposed under the inorganic layer IO. The transmission part TP may be in direct contact with the inorganic layer IO. The transmission part TP may be arranged to overlap the third pixel area PXA3. A color filter part may not be disposed on the transmission part TP. The transmission part TP may transmit the first light provided by the display panel DP. In one embodiment, for example, the first light may be blue light. Therefore, the third pixel area PXA3 may provide blue light.

The transmission part TP may include a base resin and a scatterer SP. The base resin included in the transmission part TP may be a transparent resin. The scatterer SP may be dispersed in the base resin included in the transmission part TP.

The scatterer SP scatters incident light in various directions to increase light output efficiency. The scatterer SP may include a light reflective material or a material having a predetermined refractive index. In one embodiment, for example, the scatterer SP may include at least one selected from TiO<NUM>, ZrO<NUM>, Al<NUM>O<NUM>, SiO<NUM>, MgO, In<NUM>O<NUM>, ZnO, SnO<NUM>, Sb<NUM>O<NUM>, SiO<NUM> and indium tin oxide ("ITO").

Although not shown in the drawing, the wavelength control units WC1 and WC2 may further include a scatterer SP. The scatterer SP may be dispersed in a base resin included in each of the first wavelength control unit WC1 and the second wavelength control unit WC2. The scatterer SP may be included in each of the first wavelength control unit WC1, the second wavelength control unit WC2, and the transmission part TP. However, the scatterer SP may be included only in one of the first wavelength control unit WC1, the second wavelength control unit WC2, and the transmission part TP.

A thickness of the transmission part TP may be greater than a thickness of the first wavelength control unit WC1 and a thickness of the second wavelength control unit WC2. As the color filter part is not placed on the transmission part TP, steps may be defined or formed on the light control member LP-a and LP-b, and the thickness of the transmission part TP may be greater than the thickness of the first wavelength control unit WC1 and the thickness of the second wavelength control unit WC2 to reduce the difference in that step.

Referring to <FIG>, the transmission part TP may further include a colorant CM. The colorant CM may be dispersed in the base resin included in the transmission part TP. The colorant CM may transmit light in a specific wavelength range. The colorant CM transmits the first light provided by the display panel DP and absorbs the second light and the third light having a wavelength range different from the first light. For example, the colorant CM can transmit blue light and absorb red light and green light. The colorant CM may be a blue colorant, and may include a blue pigment or blue dye.

After providing or forming the light control member LP-a and LP-b on the cover layer CV, the wavelength control layer WCL may be provided or formed by forming a partition part BK in which a plurality of opening parts are defined on the light control member LP-a and LP-b, providing a first wavelength control unit WC1 in some of the plurality of opening parts, placing a second wavelength control unit WC2 in another part of the plurality of opening parts, and providing a transmission part TP in the remaining part of the plurality of opening parts. The first wavelength control unit WC1, the second wavelength control unit WC2, and the transmission part TP may be formed using an inkjet process.

The capping layer CP may be disposed between the wavelength control layer WCL and the encapsulation layer TFE. The capping layer CP may be disposed on the lower surface of the wavelength control layer WCL to cover the wavelength control layer WCL. The capping layer CP may protect the wavelength control layer WCL from oxygen, moisture, and foreign matter. The capping layer CP may include at least one selected from silicon oxide, titanium oxide, and aluminium oxide, but not being limited thereto. In an alternative display device DD the capping layer CP may be omitted.

A display device DD may be manufactured by sequentially stacking the light control members LP-a and LP-b, the wavelength control layer WCL and the capping layer CP on the cover layer CV along one direction and arranging the stacked structure in a way such that the capping layer CP is provided or disposed to face the encapsulation layer TFE, but not being limited thereto. A display device DD may be manufactured by other methods than the above-described manufacturing method.

<FIG> shows a graph of light transmittance according to a wavelength of a second light control layer. The second light control layer LL2 may include an organic film, in which the light transmittance in the yellow light wavelength range is less than the light transmittance in the blue light wavelength range. For example, the light transmittance of the second light control layer LL2 may exhibit a trend as shown in the graph of <FIG>.

Referring to <FIG>, the light transmittance of the second light control layer LL2 gradually decreases for light having a wavelength of about <NUM> or greater, and may have a value of <NUM>% or less in a wavelength range of about <NUM> to about <NUM>. In particular, the light transmittance in the wavelength range of <NUM> to <NUM> may have a value of <NUM>% or less.

The organic film having a light transmittance of the yellow light wavelength range less than the light transmittance of the blue light wavelength range is included in the second light control layer LL2, such that the transmittance of light having a wavelength of about <NUM> or greater among the external light in the visible light region may be reduced. Accordingly, the external light reflectance of the display device DD may be more effectively reduced by including the second light control layer LL2. However, the graph illustrated in <FIG> is merely an example, and the organic film included in the second light control layer LL2 is not limited to having a light transmittance value as illustrated in <FIG>.

<FIG> is an enlarged cross-sectional view of a portion AA of the display device illustrated in <FIG>. <FIG> is an enlarged cross-sectional view of a portion BB of the display device illustrated in <FIG>. <FIG> and <FIG> illustrate the enlarged cross-sectional view of the first pixel area PXA1 in which the first color filter part CF1 is disposed, but the following description may be applied to areas corresponding to other pixel areas (e.g., second and third pixel areas PXA2 and PXA3).

The speed of light may be changed or varied by a medium through which it passes. When the wave of light meets the interface of mediums having a different refractive index, some are transmitted but some are reflected. The reflected light may or may not change the phase depending on the refractive index of the medium.

Referring to <FIG>, the upper surface of the first light control layer LL1 contacts the first color filter part CF1, and the lower surface of the first light control layer LL1 contacts the inorganic layer IO. The upper surface of the inorganic layer IO is in contact with the first light control layer LL1, and the lower surface of the inorganic layer IO is in contact with the first wavelength control unit WC1.

The inorganic layer IO has a first refractive index n1, and the first light control layer LL1 has a second refractive index n2. The second refractive index n2 is less than the refractive index of the first color filter part CF1 and the first refractive index n1. In an embodiment, the second refractive index n2 is less than that of the first color filter part CF1 and first wavelength control unit WC1 to improve the viewing angle and increase the wavelength conversion efficiency. The first refractive index n1 is greater than the second refractive index n2 and less than the refractive index of the first wavelength control unit WC1.

In relation to the light L1 incident on a portion of the display device DD, some light L1-<NUM> may be transmitted at the interface between the first color filter part CF1 and the first light control layer LL1, and some light RL1-<NUM> may be reflected. Some light L1-<NUM> of the light L1-<NUM> transmitted through the first light control layer LL1 may pass through the inorganic layer IO and some light of the light L1-<NUM> may be reflected. Some light RL1-<NUM> of the light L1-<NUM> transmitted into the inorganic layer IO may be reflected at the interface between the inorganic layer IO and the first wavelength control unit WC1.

As the difference in refractive index is greater, the critical angle at which total reflection occurs is less and the reflected amount of light is greater. Accordingly, the amount of reflected light may be reduced by arranging the inorganic layer IO having a refractive index value between the second refractive index n2 and the refractive index of the first wavelength control unit WC1. The difference in refractive index between the first refractive index n1 and the first wavelength control unit WC1 is less than the difference in refractive index between the second refractive index n2 and the first wavelength control unit WC1, so that the amount of light RL1-<NUM> reflected at the interface between the inorganic layer IO and the first wavelength control unit WC1 may be decreased.

The thickness D1 of the inorganic layer IO may affect light reflectance according to a wavelength range. The thickness D1 of the inorganic layer IO may be adjusted to reduce light reflectance in a wavelength range of the visible region. In an inventive embodiment, the relation between the refractive indices n2<n1<nWCL holds and the thickness D1 is in a range of about <NUM> kÅ to about <NUM> kÅ.

Referring to <FIG>, the light control member LP-b may further include a second light control layer LL2. The upper surface of the first light control layer LL1 contacts the second light control layer LL2, and the first color filter part CF1 contacts the upper surface of the second light control layer LL2.

The second light control layer LL2 has a third refractive index n3. In an inventive embodiment, the relation between the refractive indices n2<n1<nWCL holds and the third refractive index n3 is less than the refractive index of the first color filter part CF1 and greater than the second refractive index n2.

In relation to the light L1 incident on a portion of the display device DD, some light L2-<NUM> may be transmitted at the interface between the color filter part CF1 and the second light control layer LL2, and some light RL2-<NUM> may be reflected. Some light L2-<NUM> of the light L2-<NUM> transmitted through the second light control layer LL2 may pass through the first light control layer LL1, and some light of the light L2-<NUM> may be reflected. Some light L2-<NUM> of the light L2-<NUM> transmitted into the first light control layer LL1 may transmit the inorganic layer IO, and some light RL2-<NUM> may be reflected at the interface between the inorganic layer IO and the wavelength control unit WC1.

Since the difference between the refractive index of the first color filter part CF1 and the third refractive index n3 is less than the difference between the refractive index of the first color filter part CF1 and the second refractive index n2, the amount of light L2-<NUM> transmitted from the interface between the first color filter part CF1 and the second light control layer LL2 may be greater than the amount of light L1-<NUM> (see <FIG>) transmitted from the interface between the first color filter part CF1 and the first light control layer LL1. The amount of reflected light RL2-<NUM> from the interface between the first color filter part CF1 and the second light control layer LL2 may be less than the amount of the reflected light RL1-<NUM> (see <FIG>) from the interface between the first color filter part CF1 and the first light control layer LL1.

When the phases of the wavelengths are opposite to each other, light having the opposite phases may cancel each other and the external light reflectance may be reduced through the destructive interference effect. The light RL2-<NUM> and RL2-<NUM> reflected at each interface may cancel out depending on the phase. The destructive interference effect may be maximized by adjusting the thickness D1 of the inorganic layer IO and the thickness D2 of the second light control layer LL2. In one embodiment, for example, the thickness D1 of the inorganic layer IO may be in a range of about <NUM> kÅ to about <NUM> kÅ, and the thickness D2 of the second light control layer LL2 may be in a range of about <NUM> kÅ to about <NUM> kÅ and about <NUM> kÅ to about <NUM> kÅ.

<FIG> shows a graph of reflectance according to wavelengths of Inventive Embodiment Example <NUM>, Example <NUM>, and Comparative Example. Invenitve Embodiment Example <NUM> is a display device having the configuration of the embodiment of the display device DD shown in <FIG> and featuring a thickness of the inorganic layer IO of <NUM> kÅ (<NUM>). Example <NUM> is a display device having the configuration of the embodiment of the display device DD shown in <FIG>. Comparative Example is a display device in the configuration of the display device DD of the embodiment shown in <FIG> as in Inventive Embodiment Example <NUM> but having an inorganic layer of a different thickness from Inventive Embodiment Example <NUM>.

Inventive Example <NUM> is a display device including a first light control layer LL1 and an inorganic layer IO and the thickness of the inorganic layer IO is about <NUM> kÅ. Example <NUM> is a display device including a first light control layer LL1, a second light control layer LL2, and an inorganic layer IO, and the thickness of the inorganic layer IO is about <NUM> kÅ, and the thickness of the second light control layer LL2 is about <NUM> kÅ. Comparative Example is a display device including a first light control layer LL1 and an inorganic layer IO and the thickness of the inorganic layer IO is about <NUM> kÅ.

Referring to <FIG>, it can be seen that the graph trend of reflectance according to the wavelength of Comparative Example is different from the graph trend of reflectance according to the wavelength of Embodiment Example <NUM> and Example <NUM>. In Comparative Example, the shape of the graph is convex upward in the wavelength range of about <NUM> to about <NUM>, and Embodiment Example <NUM> and Example <NUM> are convex downward in the wavelength range of about <NUM> to about <NUM>. That is, Embodiment Example <NUM> and Example <NUM> show a tendency in which reflectance decreases compared to Comparative Example in the wavelength range of about <NUM> to about <NUM>.

This tendency may be a result of the difference in the thickness of the inorganic layer IO. The inorganic layer IO may have different tendencies to increase and decrease light reflectance according to wavelength depending on the thickness. Therefore, the wavelength range in which the reflectance decreases may vary. Since the thickness of the inorganic layer IO in Embodiment Example <NUM> and Example <NUM> is about <NUM> kÅ (<NUM>) but the thickness of the inorganic layer IO in Comparative Example is about <NUM> kÅ (<NUM>), it can be seen that the trend of the graph appears differently.

When the thickness of the inorganic layer IO is in a range of about <NUM> kÅ (<NUM>) to about <NUM> kÅ (<NUM>), it can be seen that the reflectance in the wavelength range of about <NUM> to about <NUM> is particularly low in the wavelength range of the visible light region.

In addition, when Embodiment Example <NUM> and Example <NUM> are compared, it can be seen that Example <NUM> has a greater reduction in reflectance. This is because as the second light control layer LL2 is further included, the refractive index difference between each layer of the wavelength control layer WCL, the inorganic layer IO, the first light control layer LL1, the second light control layer LL2, and the color filter layer CFL sequentially stacked decreases, so that the degree of reflection of external light at the interface of each layer is reduced.

The thickness of the inorganic layer IO and the second light control layer LL2 may affect the phase of transmitted or reflected light. Depending on the phase of the light, constructive interference may occur or destructive interference may occur. Through the destructive interference effect, external light reflectance may be reduced. In Example <NUM>, the thickness of the inorganic layer IO is about <NUM> kÅ (<NUM>) and the thickness of the second light control layer LL2 is about <NUM> kÅ (<NUM>). Therefore, it can be seen that by adjusting the thickness of the inorganic layer IO and the thickness of the second light control layer LL2, the effect of destructive interference can be maximized and this can reduce the external light reflectance.

Table <NUM> below is a table comparing the reflectance of each pixel area of the Comparative Example and Example <NUM> and the total reflectance of the display device. "Reflectance of each pixel area" is a measured value of reflectance in each pixel area of Comparative Example and Example <NUM>. The "total reflectance" is a value that predicts the total reflectance of the display device through the reflectance of each pixel area. In Table <NUM>, the first pixel area is an area that provides red light, the second pixel area is an area that provides green light, and the third pixel area is an area that provides blue light.

As shown in Table <NUM>, in all pixel areas, the reflectance of ] Example <NUM> was reduced than that of Comparative Example. The degree of reduction in reflectance in each pixel area decreased by <NUM>% in the first pixel area, decreased by <NUM>% in the second pixel area, and decreased by <NUM>% in the third pixel area. As shown in Table <NUM>, the total reflectance prediction result is <NUM>% for Comparative Example and is <NUM>% for Example <NUM>, and the total reflectance of Example <NUM> may be reduced by about <NUM>% compared to Comparative Example.

As shown in Table <NUM>, the external light reflectance of each pixel area of the display device is reduced by the thickness of the inorganic layer, the refractive index matching between the stacked structures on the wavelength control layer of the display device, and the destructive interference effect. It can be understood that the total external light reflectance of the display device is reduced by reducing the external light reflectance corresponding to each pixel area. Accordingly, an embodiment of a display device including a light control member according to an embodiment of the invention may improve external light visibility and reliability of a display device.

In the display device, the inorganic layer and light control layers included in the light control member have a specific range of refractive indexes or thicknesses so that refractive index matching effect and destructive interference effect may occur. Accordingly, the external light visibility of the display device may be improved by reducing the external light reflectance of the display device in which color filters are omitted in some areas. Some operations of the process of disposing the color filter on the display device may be omitted, so that the display device may be manufactured relatively simply and economically.

Claim 1:
A display device (DD) comprising:
a display panel (DP);
a wavelength control layer (WCL) disposed on the display panel (DP);
a light control member (LP) disposed on the wavelength control layer (WCL); and
a cover layer (CV) disposed on the light control member (LP),
wherein the light control member (LP) comprises:
an inorganic layer (IO) disposed on the wavelength control layer (WCL) and having a first refractive index (n1);
a first light control layer (LL1) disposed on the inorganic layer (IO) and having a second refractive index (n2);
a second light control layer (LL2) disposed on the first light control layer (LL1) and having a third refractive index (n3); and
a color filter layer (CFL) disposed on the second light control layer (LL2),
characterized in that
the first refractive index (n1) is greater than the second refractive index (n2) and is less than a refractive index of the wavelength control layer (WCL), and
the third refractive index (n3) is greater than the second refractive index (n2) and is less than a refractive index of the color filter layer (CFL).