KR20130010404A - Display device - Google Patents

Abstract

PURPOSE: A display device is provided to display a color image by using a color conversion medium and a bearing portion. CONSTITUTION: A display device includes a substrate(110), a bearing portion(143) and a color conversion medium. The bearing portion is arranged on the substrate. The bearing portion includes multiple pores. The color conversion medium is arranged within the pores. The pores guide light.

Description

Display device {DISPLAY DEVICE}

The embodiment relates to a display device.

Recently, a flat panel display such as a liquid crystal display (LCD), a plasma display panel (PDP), or an organic light emitting diode (OLED) has been developed in place of the conventional CRT.

The liquid crystal display device includes a thin film transistor substrate, a color filter substrate, and a liquid crystal display panel in which liquid crystal is injected between both substrates. Since the liquid crystal display panel is a non-light emitting device, a backlight unit for supplying light to the bottom surface of the thin film transistor substrate is positioned. Light transmitted from the backlight unit is adjusted according to the arrangement of liquid crystals.

The backlight unit is divided into edge type and direct type according to the position of the light source. The edge type is a structure in which a light source is provided on a side surface of the light guide plate.

The direct type is a structure that is mainly developed with the size of a liquid crystal display device being enlarged. One or more light sources are arranged on the lower surface of the liquid crystal display panel to supply light to the liquid crystal display panel.

The direct-type backlight unit has advantages in that it can utilize a larger number of light sources than the edge-type backlight unit and can secure a high luminance, but has a disadvantage that the thickness becomes thicker than the edge type in order to ensure uniformity of brightness have.

In order to overcome this problem, a quantum dot bar in which a plurality of quantum dots dispersed in a red wavelength or a green wavelength is dispersed is provided in front of a blue LED emitting blue light constituting a backlight unit, Thus, light mixed with blue light, red light and green light by a plurality of quantum dots dispersed in the quantum dot bar is incident on the light guide plate to provide white light.

At this time, when white light is provided to the light guide plate using the quantum dot bar, high color reproduction can be realized.

The backlight unit may include an FPCB (Flexible Printed Circuits Board) for transmitting and supplying LEDs and signals to one side of a blue LED emitting blue light, and an adhesive member may be further provided on the lower surface of the FPCB.

As such, when a light emitted from a blue LED is leaked, a display device for displaying an image in various forms using white light provided to the light guide plate through the quantum dot bar is widely used.

A display device to which such a quantum dot is applied is disclosed in Korean Patent Laid-Open Publication No. 10-2011-0068110.

Embodiments provide a display device having improved luminance and color reproducibility.

In one embodiment, a display device includes a substrate; A carrier part disposed on the substrate and including a plurality of pores; And a color conversion medium disposed in the pores.

In one embodiment, a display device includes a substrate; And a plurality of color conversion parts disposed on the substrate and spaced apart from each other, wherein the color conversion parts are disposed on the substrate and include a plurality of pores; And a color conversion medium disposed in the pores.

The display device according to the exemplary embodiment may display an image having color using the carrier part and the color conversion medium. That is, the color conversion units may implement color using the carrier unit and the color conversion medium.

In particular, the color conversion medium is disposed in the pores, the pores may guide the incident light. Accordingly, the display device according to the embodiment can increase the path of light in the color conversion medium, thereby maximizing the color conversion efficiency. Thus, the display device according to the embodiment can have improved color reproducibility.

In addition, the pores may have a shape extending upward from the substrate. Therefore, the color converters may increase the straightness of the incident light. Accordingly, the display device according to the embodiment may improve the characteristics of the incident light, for example, straightness and the like, and have an improved luminance.

1 is a schematic diagram illustrating a liquid crystal display according to an embodiment.
2 is a cross-sectional view illustrating a liquid crystal panel according to an embodiment.
3 is a cross-sectional view showing one cross section of the color filter substrate.
4 is a plan view of the carrier part.
5 to 9 are views illustrating a process of manufacturing a liquid crystal display according to an embodiment.

In the description of the embodiment, each panel, member, electrode, layer, part, or substrate is formed on or under the "on" of each panel, member, electrode, layer, part, or substrate, and the like. When described as being "in" and "under" includes both those that are formed "directly" or "indirectly" through other components. In addition, the upper or lower reference of each component is described with reference to the drawings. The size of each component in the drawings may be exaggerated for the sake of explanation and does not mean the size actually applied.

1 is a schematic diagram illustrating a liquid crystal display according to an embodiment. 2 is a cross-sectional view illustrating a liquid crystal panel according to an embodiment. 3 is a cross-sectional view showing one cross section of the color filter substrate. 4 is a plan view of the carrier part. 5 to 9 are views illustrating a process of manufacturing a liquid crystal display according to an embodiment.

Referring to FIG. 1, the liquid crystal display according to the present exemplary embodiment includes a backlight unit 10 and a liquid crystal panel 20.

The backlight unit 10 emits light to the liquid crystal panel 20. In more detail, the backlight unit 10 may emit white light to the liquid crystal panel 20. The backlight unit 10 may emit surface light directly or in an edge manner to the liquid crystal panel 20. In addition, the backlight unit 10 includes a light source 11 for generating light. The light source 11 may include a plurality of light emitting diodes.

The liquid crystal panel 20 is disposed under the backlight unit 10. The liquid crystal panel 20 displays an image downward by using light emitted from the backlight unit 10. In more detail, the liquid crystal panel 20 may display an image by adjusting the intensity of light emitted from the backlight unit 10 in units of pixels.

Referring to FIG. 2, the liquid crystal panel 20 includes a color filter substrate 100, a thin film transistor substrate 200, and a liquid crystal layer 300.

The color filter substrate 100 faces the thin film transistor substrate 200. The color filter substrate 100 faces the thin film transistor substrate 200. The color filter substrate 100 is spaced apart from the thin film transistor substrate 200 at a predetermined interval. The color filter substrate 100 may include a first transparent substrate 110, a transparent conductive layer 120, a black matrix 130, a plurality of color converters 140, and a common electrode 150.

The first transparent substrate 110 is transparent and has a plate shape. The first transparent substrate 110 may be a glass substrate. In addition, the first transparent substrate 110 is an insulator.

The transparent conductive layer 120 is disposed on the first transparent substrate 110. The transparent conductive layer 120 may be entirely formed on the first transparent substrate 110. The transparent conductive layer 120 may include a transparent conductor. Examples of the material used as the transparent conductive layer 120 include indium tin oxide or indium zinc oxide.

The transparent conductive layer 120 may be used to form the carrier part 143 of the color conversion parts 140. In addition, the transparent conductive layer 120 may perform a function of the common electrode 150. That is, the common electrode 150 may apply an electric field to the liquid crystal layer 300. In this case, the common electrode 150 may be omitted.

The black matrix 130 is disposed on the transparent conductive layer 120. The black matrix 130 blocks incident light. That is, the black matrix 130 is a light blocking unit. The black matrix 130 may include openings corresponding to the pixels, respectively. As the black matrix 130, a black resin or a chromium oxide film may be used.

In addition, the black matrix 130 may perform a partition function of dividing the color converters 140 from each other. That is, the black matrix 130 may be disposed in the space between the color converters 140.

The black matrix 130 includes a metal layer 131 and a corrosion protection layer 132.

The metal layer 131 is disposed on the transparent conductive layer 120. The metal layer 131 is in direct contact with the transparent conductive layer 120. The metal layer 131 is opaque. The metal layer 131 includes aluminum. In more detail, the metal layer 131 may be made of aluminum.

The corrosion protection layer 132 is disposed on the metal layer 131. In more detail, the corrosion protection layer 132 may be in direct contact with the top surface of the metal layer 131. The anti-corrosion film 132 entirely covers the metal layer 131. The planar shape of the corrosion protection layer 132 may match the planar shape of the metal layer 131.

As the corrosion preventing film 132, an organic material such as a polymer may be used. In more detail, a photoresist or the like may be used as the corrosion preventing film 132.

The metal layer 131 may block light, and the anti-corrosion layer 132 may perform a partition wall function.

The color converters 140 are disposed on the first transparent substrate 110. In more detail, the color converters 140 are disposed on the transparent conductive layer 120. In more detail, the color converters 140 are disposed in the openings of the black matrix 130. The color converters 140 may be surrounded by the black matrix 130. That is, the color converters 140 may be spaced apart from each other by the black matrix 130.

The color converters 140 may receive white light and emit light having a color. For example, the color converters 140 may receive white light and emit red light, green light, or blue light. That is, the color converters 140 may include a first color converter that emits red light, a second color converter that emits green light, and a third color converter that emits blue light.

The color conversion parts 140 include a carrier part 143 and a color conversion medium.

The carrier part 143 is disposed on the transparent conductive layer 120. The carrier part 143 is disposed in the black matrix 130. The carrier part 143 is disposed directly on the transparent conductive layer 120.

The carrier part 143 includes a plurality of pores 144. The pores 144 may have a diameter of about 20 nm to about 400 nm. The pores 144 may have a shape extending upward from the first transparent substrate 110. The pores 144 may extend from an upper surface of the transparent conductive layer 120 to an upper surface of the carrier part 143. That is, the pores 144 may penetrate the carrier part 143.

As shown in Figure 3 and 4, the pores 144 may have a hexagonal pillar shape. That is, the carrier part 143 itself may have a partition wall shape.

The carrier part 143 may be transparent. The carrier part 143 may have a refractive index of about 1.7 to 1.9. Examples of the material used as the carrier part 143 include aluminum oxide and the like. In more detail, the carrier part 143 may be made of aluminum oxide.

The color conversion medium is disposed in the pores 144. The color conversion medium may be filled in the pores 144. The color conversion medium may also be disposed on the carrier portion 143.

The color conversion medium may include quantum dots, phosphors, dyes or pigments. In more detail, the color conversion medium may convert the wavelength of incident light, filter light of a predetermined wavelength band from the incident light, and pass light of a specific wavelength band.

The color conversion medium may be disposed in the pores 144 in the form of particles. For example, the color conversion medium may be disposed in the pores 144 in the form of a plurality of wavelength conversion particles 141.

In more detail, the color conversion parts 140 include the carrier part 143, the host 142, and the wavelength conversion particles 141 as the color conversion medium.

The host 142 is disposed in the pores 144. The host 142 sprays the wavelength conversion particles 141. The host 142 is transparent. Examples of the material used for the host 142 include silicone resins.

The wavelength converting particles 141 are disposed in the host 142. In more detail, the wavelength conversion particles 141 are uniformly dispersed in the host 142. The wavelength conversion particles 141 may convert the wavelength of incident light.

The wavelength conversion particles 141 convert the wavelength of incident light. In more detail, the wavelength conversion particles 141 may convert light of a first wavelength band into light of a second wavelength band and light of a third wavelength band among the incident light. For example, when blue light is incident on the wavelength conversion particles 141, the wavelength conversion particles 141 may be converted into red light or green light.

The wavelength conversion particles 141 may be a quantum dot (QD). The quantum dot may include a core nanocrystal and a shell nanocrystal surrounding the core nanocrystal. In addition, the quantum dot may include an organic ligand bound to the shell nanocrystal. In addition, the quantum dot may include an organic coating layer surrounding the shell nanocrystals.

The shell nanocrystals may be formed of two or more layers. The shell nanocrystals are formed on the surface of the core nanocrystals. The quantum dot may convert the wavelength of the light incident on the core core crystal into a long wavelength through the shell nanocrystals forming the shell layer and increase the light efficiency.

The quantum dot may include at least one of a group II compound semiconductor, a group III compound semiconductor, a group V compound semiconductor, and a group VI compound semiconductor. More specifically, the core nanocrystals may include Cdse, InGaP, CdTe, CdS, ZnSe, ZnTe, ZnS, HgTe or HgS. The shell nanocrystals may include CuZnS, CdSe, CdTe, CdS, ZnSe, ZnTe, ZnS, HgTe or HgS.

The wavelength of the light emitted from the quantum dot can be adjusted according to the size of the quantum dot. The diameter of the quantum dot used in the wavelength conversion particles 141 may be about 1 nm to 10 nm.

The organic ligand may include pyridine, mercapto alcohol, thiol, phosphine, phosphine oxide, and the like. The organic ligands serve to stabilize unstable quantum dots after synthesis. After synthesis, a dangling bond is formed on the outer periphery, and the quantum dots may become unstable due to the dangling bonds. However, one end of the organic ligand is in an unbonded state, and one end of the unbound organic ligand bonds with the dangling bond, thereby stabilizing the quantum dot.

Particularly, when the quantum dot has a size smaller than the Bohr radius of an exciton formed by electrons and holes excited by light, electricity or the like, a quantum confinement effect is generated to have a staggering energy level and an energy gap The size of the image is changed. Further, the charge is confined within the quantum dots, so that it has a high luminous efficiency.

Unlike general fluorescent dyes, the quantum dots vary in fluorescence wavelength depending on the particle size. That is, as the size of the particle becomes smaller, it emits light having a shorter wavelength, and the particle size can be adjusted to produce fluorescence in a visible light region of a desired wavelength. In addition, since the extinction coefficient is 100 to 1000 times higher than that of a general dye, and the quantum yield is also high, it produces very high fluorescence.

The quantum dot can be synthesized by a chemical wet process. Here, the chemical wet method is a method of growing particles by adding a precursor material to an organic solvent, and the quantum dots can be synthesized by a chemical wet method.

In addition, the wavelength conversion particles 141 may include a phosphor. In more detail, the wavelength conversion particles 141 may be phosphors. In more detail, the wavelength conversion particles 141 and 241 may include a red phosphor or a green phosphor.

Examples of the red phosphor include strontium titanium oxide phosphors doped with praseodymium or aluminum (eg, SrTiO 3: Pr, Al) or calcium titanium oxide phosphors doped with praseodymium (eg, CaTiO 3: Pr). have.

Examples of the green phosphor include zinc manganese doped zinc silicon oxide phosphors (eg, Zn 2 SiO 4: Mn), europium doped strontium gallium sulfide phosphors (eg, SrGa 2 S 4: Eu) or europium doped barium silicon oxide. Chloride-based phosphors (for example, Ba 5 Si 2 O 7 Cl 4: Eu) and the like.

The color conversion medium may also comprise dyes and / or pigments. The dyes and pigments absorb light in a predetermined wavelength range and reflect or transmit light in a predetermined wavelength range. For example, the dyes and pigments may absorb blue light and green light, and reflect or transmit red light among incident white light. In addition, the dye and the pigment may absorb blue light and red light, and reflect or transmit green light among the white light. In addition, the dyes and pigments may absorb the white light, red light and green light, and may reflect or transmit blue light.

That is, the dyes and pigments may absorb light of a predetermined wavelength band and may reflect or transmit light of a specific wavelength band. For example, the dyes and pigments may be red dyes and red pigments. For example, a perylene compound or a diketo pyrrolo pyrrole compound may be used as the red dye and the red pigment. In addition, the dyes and pigments may be green dyes and green pigments. For example, a phthalocyanine compound may be used as the green dye and the green pigment. In addition, the dyes and pigments may be blue dyes and blue pigments. For example, as the blue dye and pigment, a copper phthalocyanine compound or an anthraquinone compound may be used.

The dye and pigment may be disposed in the pores 144 in the form of particles. That is, the dye and the pigment may be dispersed in the host 142 in the form of particles, such as the wavelength conversion particles 141, and the host 142 may be filled in the pores 144.

Alternatively, the dye and pigment may be adsorbed on the carrier portion 143. That is, the dye and the pigment may be adsorbed to the carrier portion 143 in the form of ions.

The common electrode 150 is disposed on the first transparent substrate 110. In more detail, the common electrode 150 is disposed on the color converters 140 and the black matrix. In addition, an overcoat layer may be interposed between the color converters 140 and the common electrode 150.

The common electrode 150 is a transparent conductor, and examples of the material used as the common electrode 150 include indium tin oxide or indium zinc oxide.

In addition, an alignment layer may be interposed between the common electrode 150 and the liquid crystal layer 300. The alignment layer may determine the alignment direction of the liquid crystal included in the liquid crystal layer 300.

The thin film transistor substrate 200 faces the color filter substrate 100. The thin film transistor substrate 200 may apply an electric field in units of pixels to the liquid crystal layer 300 together with the color filter substrate 100. The thin film transistor substrate 200 includes a second transparent substrate 210 and a plurality of pixel electrodes 220.

The second transparent substrate 210 is disposed on the color filter substrate 100. The second transparent substrate 210 is disposed on the first transparent substrate 110 and faces the first transparent substrate 110. The second transparent substrate 210 is transparent and has a plate shape. The second transparent substrate 210 may be a glass substrate. In addition, the second transparent substrate 210 is an insulator.

The pixel electrodes 220 are disposed under the second transparent substrate 210. The pixel electrodes 220 apply an electric field to the liquid crystal layer 300. The pixel electrodes 220 may be disposed to correspond to the pixels of the liquid crystal panel 20, respectively. Accordingly, an electric field may be applied to the pixels of the liquid crystal panel 20 by the pixel electrodes 220.

The pixel electrodes 220 are transparent and are conductors. Examples of the material used as the pixel electrodes 220 may include indium tin oxide or indium zinc oxide.

Although not shown in the drawing, the thin film transistor substrate 200 may further include a plurality of gate lines, a plurality of data lines crossing the gate lines, and a plurality of thin film transistors.

The gate lines extend in parallel to each other and apply a gate signal to the thin film transistors. That is, the gate lines are lines for applying a gate signal for driving the thin film transistors.

The data lines apply data signals to the pixel electrodes 220 by the thin film transistors. In response to the data signal, the pixel electrodes 220 apply an electric field to the liquid crystal layer 300. That is, the data signal is a predetermined voltage for the pixel electrodes 220 to apply an electric field to the liquid crystal layer 300.

The thin film transistors may be disposed in an area where the gate lines and the data lines cross. The thin film transistors may perform a switch function between the data lines and the pixel electrodes 220. That is, the thin film transistors selectively connect the pixel electrodes 220 and the data lines according to the gate signal.

The thin film transistor substrate 200 may further include insulating layers (not shown) to insulate the gate lines, the data lines, and the pixel electrodes 220.

The liquid crystal layer 300 is interposed between the thin film transistor substrate 200 and the color filter substrate 100. In more detail, the liquid crystal layer 300 is interposed between the pixel electrode 140 and the common electrode 150. In addition, an alignment layer may be interposed between the thin film transistor substrate 200 and the liquid crystal layer 300 and between the color filter substrate 100 and the liquid crystal layer 300.

The liquid crystal layer 300 is aligned by an electric field between the common electrode 150 and the pixel electrodes 220. Accordingly, the liquid crystal layer 300 may adjust the characteristics of the light passing through in units of pixels. That is, the liquid crystal layer 300 displays images by an applied electric field together with polarization filters disposed on the second transparent substrate 210 and below the first transparent substrate 110, respectively.

Smatic liquid crystal, nematic liquid crystal or cholesteric liquid crystal may be used as the liquid crystal layer 300.

In order to form the liquid crystal panel 20, the color filter substrate 100 may be formed by the following process.

Referring to FIG. 5, a transparent conductive material is deposited on the first transparent substrate 110 to form a transparent conductive layer 120. Thereafter, aluminum is deposited on the transparent conductive layer 120 to form a metal layer 131. The metal layer 131 may be formed by a sputtering process. Thereafter, a corrosion protection film 132 is formed on the metal layer 131. The corrosion preventing film 132 may be formed of a polymer such as a photoresist. The corrosion prevention layer 132 may be patterned by an exposure process and an etching process.

Referring to FIG. 6, the carrier part 143 is formed in a region where the corrosion preventing film 132 is not disposed. The carrier part 143 may be formed by eluting an oxide film by an electric field.

The gold layer 131 is contained in an electrolyte. Subsequently, when an anode (+) is applied to the metal layer 131 and a cathode (−) is applied to the counter electrode through the transparent conductive layer 120, aluminum ions of the metal layer 131 are eluted into a solution. . These aluminum ions react with oxygen (or hydroxide ions) in the electrolyte to form alumina.

At this time, the alumina grows in the direction in which the electric field is formed, that is, the direction perpendicular to the aluminum layer. In addition, the height of growth may vary depending on the time the electric field is applied. Accordingly, pores 144 extending in one direction may be formed. After the etching process, the size of the pores 144 may be controlled. The pores 144 may have a diameter of about 20 nm to about 400 nm. In addition, the heights of the pores 144 may be about 200 nm to about several hundred μm.

By such a process, the carrier part 143 including the pores 144 is formed. The pores 144 may be self-aligned in a direction perpendicular to the transparent conductive layer 120.

Referring to FIG. 7, a color conversion medium may be doped into the carrier unit 143 by an ink jet apparatus or the like. For example, the resin composition including the wavelength conversion particles 141 is doped into the carrier part 143, respectively. The doped resin composition may be filled in the pores 144 by a capillary phenomenon.

Thereafter, the resin composition filled in the pores 144 is cured by light and / or heat, and a plurality of color conversion parts 140 are formed in the corrosion preventing film 132.

Referring to FIG. 8, a transparent conductive material is deposited on the color conversion unit 140 and the corrosion protection layer 132, and a common electrode 150 is formed. Accordingly, the color filter substrate 100 may be formed.

Referring to FIG. 9, a thin film transistor substrate 200 is disposed on the color filter substrate 100, and a liquid crystal is injected between the two substrates to form a liquid crystal layer 300. Accordingly, the liquid crystal panel 20 is formed.

As described above, the liquid crystal display according to the exemplary embodiment may display an image having color using the carrier unit 143 and the color conversion medium. That is, the color conversion units 140 may implement color using the carrier unit 143 and the color conversion medium.

In particular, the color conversion medium may be disposed in the pores 144, and the pores 144 may guide the incident light. Accordingly, the liquid crystal display according to the embodiment can increase the path of light in the color conversion medium, thereby maximizing the color conversion efficiency. Thus, the liquid crystal display according to the embodiment may have improved color reproducibility.

In addition, the pores 144 may have a shape extending upward from the first transparent substrate 110. Therefore, the color converters 140 may increase the straightness of the incident light. Therefore, the liquid crystal display according to the embodiment may improve the characteristics of the incident light, for example, straightness and the like, and have an improved luminance.

In the present embodiment, the liquid crystal display device is described, but the present invention is not limited thereto. That is, the structures of the black matrix 130 and the color converter 140 may be applied to various display devices displaying an image in color. For example, instead of the liquid crystal layer 300, an organic emission layer may be interposed between the pixel electrodes 220 and the common electrode 150. That is, the structures of the black matrix 130 and the color converter 140 according to the present exemplary embodiment may be modified and applied to various display devices such as an organic light emitting display device.

In addition, the features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in each embodiment may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (12)

Board;
A carrier part disposed on the substrate and including a plurality of pores; And
And a color conversion medium disposed in the pores. The display device of claim 1, wherein the pores extend upward from the substrate. The display device of claim 1, wherein the carrier portion comprises aluminum oxide. The display device of claim 1, wherein the color conversion medium comprises a dye, a pigment, a compound semiconductor, or a phosphor. The display device of claim 1, wherein the pores have a diameter of about 20 nm to about 400 nm. The display device of claim 1, further comprising a conductive layer interposed between the substrate and the carrier portion. Board; And
A plurality of color conversion parts disposed on the substrate and spaced apart from each other,
The color converters
A carrier part disposed on the substrate and including a plurality of pores; And
And a color conversion medium disposed in the pores. The method of claim 7, further comprising a light blocking unit disposed between the color conversion unit,
The light blocking unit includes a metal layer on the substrate. The display device of claim 8, wherein the metal layer comprises aluminum. The display device of claim 7, wherein the carrier portion is transparent. The display device of claim 7, further comprising a liquid crystal layer disposed on the color converter. The display device of claim 7, further comprising a light emitting layer on the color converter.

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