KR20130069251A - Optical member, display device having the same and method of fabricating the same - Google Patents

Abstract

PURPOSE: An optical member, a display device having the same, and a method for fabricating the same are provided to prevent the damage due to external impact by using a light conversion part and a light conversion partition wall used as a wavelength conversion layer. CONSTITUTION: An optical member includes a first substrate(410), a light converse partition wall(440), and a light conversion part(450). The light conversion partition wall is arranged on the first substrate. The light conversion part is arranged in the light conversion partition wall. The light conversion particles for changing the wavelength of incident light are formed between the light conversion partition walls. A wavelength conversion layer(430) is arranged on the first substrate.

Description

Optical member, display device including same, and manufacturing method therefor {OPTICAL MEMBER, DISPLAY DEVICE HAVING THE SAME AND METHOD OF FABRICATING THE SAME}

Embodiments relate to an optical member, a display device including the same, and a manufacturing method thereof.

Among display devices, there is a device that requires a backlight unit capable of generating light in order to display an image. The backlight unit is a device for supplying light to a display panel including a liquid crystal or the like and includes a light emitting device and means for effectively transmitting the light output from the light emitting device to the liquid crystal side.

As a light source of such a display device, a light emitting diode (LED) or the like may be applied. In addition, in order to effectively transmit the light output from the light source to the display panel side, a light guide plate, an optical sheet, or the like may be stacked and used.

In this case, an optical member or the like that changes the wavelength of light generated from the light source and injects white light into the light guide plate or the display panel may be applied to the display device. In particular, in order to change the wavelength of light, quantum dots or the like can be used.

Quantum dots have a particle size of 10 nm or less and have unique electro-optic properties depending on their size. For example, when the approximate size is 55 to 65 Å, it can emit red, 40 to 50 Å to green, and 20 to 35 Å to blue. Yellow has medium size of red and green quantum dots. As the spectrum of light changes from red to blue, the size of the quantum dots varies from 65 Å to 20 Å, which may be slightly different.

In order to form the optical member including the quantum dots, quantum dots emitting RGB or RYGB, which are three primary colors of light, may be formed by spin coating or printing a transparent substrate such as glass. In this case, when the quantum dot emitting yellow (Y) is further included, white light closer to natural light may be obtained. The matrix (medium) in which the quantum dots are dispersed can apply an inorganic substance or a polymer having excellent transmittance with respect to light in the visible light region and the ultraviolet region (including Far UV) or in the visible light region. For example, it may be inorganic silica, polymethylmethacrylate (PMMA), polydimethylsiloxane (PDMS), poly lactic acid (PLA), silicon polymer or YAG. In particular, such quantum dots and medium may be denatured or damaged by heat.

A display device to which such quantum dots are applied is disclosed in Korean Patent Laid-Open Publication No. 10-2011-0012246.

Embodiments provide an optical member having improved durability and reliability, a display device including the same, and a manufacturing method thereof.

An optical member according to an embodiment includes a first substrate; A light conversion barrier disposed on the first substrate; And a light conversion unit disposed in the light conversion partition.

A display device according to an embodiment includes: a light source; A light conversion member on which light from the light source is incident; And a display panel to which light from the light conversion member is incident, wherein the light conversion member includes a light conversion barrier including a plurality of accommodation portions; A plurality of light conversion units disposed in the accommodation units, respectively; And a first substrate and a second substrate sandwiching the light conversion partition and the light conversion units.

In the method for manufacturing an optical member according to an embodiment, a resin composition comprising a photocurable resin and a plurality of light conversion particles is coated on a first substrate to form a resin composition layer, and a second substrate is formed on the resin composition layer. Laminating and selectively irradiating light to the resin composition layer to form a light conversion partition and a plurality of light conversion sections separated by the light conversion partition.

The optical member according to the embodiment includes a first substrate, a second substrate, and a wavelength conversion layer disposed between the first substrate and the second substrate and including a light conversion partition and a light conversion unit.

That is, since a plurality of light conversion partitions are formed in the wavelength conversion layer, and a light conversion unit including light conversion particles is disposed between the light conversion partitions, the light conversion partitions can block contact with the outside. The damage by external shock can be prevented.

Accordingly, the optical member according to the embodiment can effectively block external oxygen or moisture by the light conversion partition wall, and absorb the impact from the outside to prevent damage to the optical member.

In addition, since the light conversion partition also includes light conversion particles, the wavelength of the light source passing through the light conversion partition can also be converted, thereby improving color reproducibility and color uniformity of the liquid crystal display device.

Therefore, the optical member and the display device including the optical member according to the embodiment can have improved durability and reliability, and the partition of the liquid crystal display device is not only a light conversion part but also a partition wall including light conversion particles. There is an effect that can improve the reproducibility and color uniformity.

1 is an exploded perspective view illustrating a liquid crystal display according to an embodiment.
2 is a perspective view showing an optical member according to an embodiment.
3 is a cross-sectional view showing a cross section of the wavelength conversion layer according to the embodiment.
4 is a cross-sectional view illustrating a cross section taken along AA ′ in FIG. 2.
5 to 7 are views illustrating a process of manufacturing the optical member.

In the description of the embodiments, it is described that each substrate, frame, sheet, layer or pattern is formed "on" or "under" each substrate, frame, sheet, In this case, "on" and "under " all include being formed either directly or indirectly through another element. 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 an exploded perspective view showing a liquid crystal display device according to a first embodiment. 2 is a perspective view illustrating an optical member according to an embodiment. 3 is a cross-sectional view showing a cross section of the wavelength conversion layer. 4 is a cross-sectional view illustrating a cross section taken along line AA ′ in FIG. 2. 5 to 8 are views illustrating a process of manufacturing the wavelength conversion member.

1 to 4, the liquid crystal display according to the embodiment includes a backlight unit 10 and a liquid crystal panel 20.

The backlight unit 10 emits light to the liquid crystal panel 20. The backlight unit 10 may uniformly irradiate light onto the bottom surface of the liquid crystal panel 20 with a surface light source.

The backlight unit 10 is disposed under the liquid crystal panel 20. The backlight unit 10 may include a bottom cover 100, a light guide plate 200, a reflective sheet 201, a light source, for example, a plurality of light emitting diodes 300, a printed circuit board 301, and an optical member 400. ) And a plurality of optical sheets 500.

The bottom cover 100 has a shape in which an upper portion thereof is opened. The bottom cover 100 accommodates the light guide plate 200, the light emitting diodes 300, the printed circuit board 301, the reflective sheet 201, and the optical sheets 500.

The light guide plate 200 is disposed in the bottom cover 100. The light guide plate 200 is disposed on the reflective sheet 201. The light guide plate 200 emits light incident from the light emitting diodes 300 upward through total reflection, refraction, and scattering.

The reflective sheet 201 is disposed under the light guide plate 200. In more detail, the reflective sheet 201 is disposed between the light guide plate 200 and the bottom surface of the bottom cover 100. The reflective sheet 201 reflects light emitted from the lower surface of the light guide plate 200 upward.

The light emitting diodes 300 are light sources for generating light. The light emitting diodes 300 are disposed on one side of the light guide plate 200. The light emitting diodes 300 generate light and enter the light guide plate 200 through a side surface of the light guide plate 200.

The light emitting diodes 300 may be blue light emitting diodes generating blue light or UV light emitting diodes generating ultraviolet light. That is, the light emitting diodes 300 may generate blue light having a wavelength band between about 430 nm and about 470 nm or ultraviolet rays having a wavelength band between about 300 nm and about 400 nm.

The light emitting diodes 300 are mounted on the printed circuit board 301. The light emitting diodes 300 are disposed under the printed circuit board 301. The light emitting diodes 300 are driven by receiving a driving signal through the printed circuit board 301.

The printed circuit board 301 is electrically connected to the light emitting diodes 300. The printed circuit board 301 may mount the light emitting diodes 300. The printed circuit board 301 is disposed inside the bottom cover 100.

The optical member 400 may be disposed on an optical path between the light source and the liquid crystal panel 20. In more detail, the optical member 400 is interposed between the light emitting diodes 300 and the light guide plate 200. In more detail, the optical member 400 is adhered to the light guide plate 200. In more detail, the optical member 400 is bonded to the incident surface of the light guide plate 200.

The optical member 400 may have a shape extending in one direction. In more detail, the optical member 400 may have a shape extending along the incident surface of the light guide plate 200.

The optical member 400 may convert the light emitted from the light emitting diodes 300 and output the light to the light guide plate 200.

For example, when the light emitting diodes 300 are blue light emitting diodes, the optical member 400 may convert blue light emitted upward from the light guide plate 200 into green light and red light. That is, the optical member 400 converts a part of the blue light into green light having a wavelength band of about 520 nm to about 560 nm, and another part of the blue light of red light having a wavelength band of about 630 nm to about 660 nm. Can be converted to

In addition, when the light emitting diodes 300 are UV light emitting diodes, the optical member 400 may convert ultraviolet light emitted from the upper surface of the light guide plate 200 into blue light, green light, and red light. That is, the optical member 400 converts a part of the ultraviolet light into blue light having a wavelength band between about 430 nm and about 470 nm, and green light having a wavelength band between about 520 nm and about 560 nm. And another portion of the ultraviolet light to red light having a wavelength band between about 630 nm and about 660 nm.

Accordingly, the light passing through the optical member 400 without being converted and the light converted by the optical member 400 may form white light. That is, blue light, green light, and red light may be combined to allow white light to enter the liquid crystal panel 20.

As shown in Figures 2-4. The optical member 400 includes a first substrate 410, a wavelength conversion layer 430 disposed on the first substrate 410, a light conversion partition 440 formed on the wavelength conversion layer 430, and the The light conversion part 450 is disposed in the light conversion partition 440 and the second substrate 420 is disposed on the light conversion partition 440.

Examples of the material used as the first substrate include transparent polymers such as polyethyleneterephthalate (PET) and the like. In addition, the first substrate 410 may directly contact the bottom surface of the light conversion partition 440.

The second substrate may be transparent and flexible. In addition, the second substrate may be in direct contact with the top surface of the light conversion partition 440.

Examples of the material used as the second substrate 420 may include a transparent polymer such as polyethylene terephthalate.

The light conversion partition 440 may be formed on the wavelength conversion layer 430. The light conversion partition 440 may include a photocurable resin and first light conversion particles 431a for converting wavelengths of incident light. For example, the photocurable resin may include an epoxy resin. In addition, the light conversion partition 440 may include a transparent polymer, and the light conversion particles may be disposed in the transparent polymer.

Hereinafter, a method of manufacturing the light conversion partition 440 will be described with reference to FIGS. 5 to 8.

First, a resin composition including a photocurable resin and a plurality of light conversion particles is coated on the first substrate to form a resin composition layer on the first substrate.

Next, the second substrate is laminated on the resin composition layer.

Subsequently, a mask including a transmission region corresponding to a region where the light conversion partition 440 is formed is disposed on the second substrate, and light is selectively irradiated onto the resin composition layer through the mask. Preferably, the resin composition layer may be irradiated with UV light for 10 to 30 minutes. Thereafter, the resin composition layer irradiated with light may be cured to form the light conversion partition 440. Accordingly, the light conversion partitions 440 and the light conversion partitions 440 separated by the light conversion partitions 440 may be formed on the resin composition layer.

That is, the light conversion partitions 440 are formed in the wavelength conversion layer 430, and an accommodating part in which the host 432 and the second light conversion particles 431b are accommodated is formed between the light conversion partitions 440. Can be. That is, the light conversion unit 450 including the host 432 and the second light conversion particles 431b may be accommodated in the accommodation unit. The accommodation unit may arrange the host 432 on an inner side of the accommodation unit, and the plurality of second light conversion particles 431b may be disposed in the host 432.

The light conversion partition 440 may include a plurality of first light conversion particles 431a. Preferably, the light conversion partition 440 is interposed between the first substrate 410 and the second substrate 420 and disposed in an isolation unit and the isolation unit surrounding the light conversion units 450, respectively. It may include a plurality of first light conversion particles 431a.

The first light conversion particles 431a and the second light conversion particles 431b convert wavelengths of light emitted from the light emitting diodes 300. The first light conversion particles 431a and the second light conversion particles 431b receive light emitted from the light emitting diodes 300 to convert wavelengths. For example, the first light conversion particles 431a and the second light conversion particles 431b may convert blue light emitted from the light emitting diodes 300 into green light and red light. That is, some of the first light conversion particles 431a and the second light conversion particles 431b convert the blue light into green light having a wavelength band between about 520 nm and about 560 nm and the first light. Other portions of the conversion particles 431a and the second light conversion particles 431b may convert the blue light into red light having a wavelength band between about 630 nm and about 660 nm.

Alternatively, the first light conversion particles 431a and the second light conversion particles 431b may convert ultraviolet light emitted from the light emitting diodes 300 into blue light, green light, and red light. That is, some of the first light conversion particles 431a and the second light conversion particles 431b convert the ultraviolet light into blue light having a wavelength band between about 430 nm and about 470 nm, and the first light Other portions of the conversion particles 431a and the second light conversion particles 431b may convert the ultraviolet light into green light having a wavelength band between about 520 nm and about 560 nm. In addition, another portion of the first light conversion particles 431a and the second light conversion particles 431b may convert the ultraviolet light into red light having a wavelength band between about 630 nm and about 660 nm.

That is, when the light emitting diodes 300 are blue light emitting diodes for generating blue light, light conversion particles for converting blue light into green light and red light may be used. Alternatively, when the light emitting diodes 300 are UV light emitting diodes that generate ultraviolet light, light conversion particles for converting ultraviolet light into blue light, green light, and red light may be used.

The light conversion particles may be quantum dots (QDs). 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 diameter of the quantum dot may be 1 nm to 10 nm.

The wavelength of the light emitted from the quantum dot can be adjusted according to the size of the quantum dot. 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.

The host 432 surrounds the first light conversion particles 431a or the second light conversion particles 431b. That is, the host 432 uniformly disperses the first light conversion particles 431a or the second light conversion particles 431b therein. The host layer may be composed of a polymer. The host layer is transparent. That is, the host layer may be formed of a transparent polymer.

The optical member according to the embodiment includes a first substrate, a second substrate, and a wavelength conversion layer disposed between the first substrate and the second substrate and including a light conversion partition and a light conversion unit.

That is, since a plurality of light conversion partitions are formed in the wavelength conversion layer, and a light conversion unit including light conversion particles is disposed between the light conversion partitions, the light conversion partitions can block contact with the outside. The damage by external shock can be prevented.

Accordingly, the optical member according to the embodiment can effectively block external oxygen or moisture by the light conversion partition wall, and absorb the impact from the outside to prevent damage to the optical member.

In addition, since the light conversion partition also includes light conversion particles, the wavelength of the light source passing through the light conversion partition can also be converted, thereby improving color reproducibility and color uniformity of the liquid crystal display device.

The optical sheets 500 are disposed on the light guide plate 200. The optical sheets 500 change or improve characteristics of light emitted from the upper surface of the light guide plate 200 to supply the light to the liquid crystal panel 20.

The optical sheets 500 may be a diffusion sheet 502, a first prism sheet 503, and a second prism sheet 504.

The diffusion sheet 502 is disposed on the wavelength conversion member 400. The diffusion sheet 502 improves the uniformity of light passing therethrough. The diffusion sheet 502 may include a plurality of beads.

The first prism sheet 503 is disposed on the diffusion sheet 502. The second prism sheet 504 is disposed on the first prism sheet 503. The first prism sheet 503 and the second prism sheet 504 increase the straightness of light passing therethrough.

The liquid crystal panel 20 is disposed on the optical sheets 500. In addition, the liquid crystal panel 20 is disposed on the panel guide 23. The liquid crystal panel 20 may be guided by the panel guide 23.

The liquid crystal panel 20 displays an image by adjusting the intensity of light passing through the liquid crystal panel 20. That is, the liquid crystal panel 20 is a display panel that displays an image by using light emitted from the backlight unit 10. The liquid crystal panel 20 includes a TFT substrate 21, a color filter substrate 22, and a liquid crystal layer interposed between the two substrates. In addition, the liquid crystal panel 20 includes polarization filters.

Although not shown in detail in the drawings, the TFT substrate 21 and the color filter substrate 22 will be described in detail. In the TFT substrate 21, a plurality of gate lines and data lines cross each other to define pixels, and respective intersections are performed. A thin flim transistor (TFT) is provided in each region and is connected in one-to-one correspondence with the pixel electrode mounted in each pixel. The color filter substrate 22 includes a color filter of R, G, and B colors corresponding to each pixel, a black matrix bordering each of them, covering a gate line, a data line, a thin film transistor, and the like, and a common electrode covering all of them. Include.

A driving PCB 25 is provided at the edge of the liquid crystal display panel 210 to supply driving signals to the gate line and the data line.

The driving PCB 25 is electrically connected to the liquid crystal panel 20 by a chip on film (COF) 24. Here, the COF 24 may be changed to a tape carrier package (TCP).

As described above, the optical member according to the embodiment includes a first substrate, a second substrate, and a wavelength conversion layer disposed between the first substrate and the second substrate and including a light conversion partition and a light conversion unit.

That is, since a plurality of light conversion partitions are formed in the wavelength conversion layer, and a light conversion unit including light conversion particles is disposed between the light conversion partitions, contact with the outside may be blocked by the light conversion partitions. The damage by external shock can be prevented.

Accordingly, the optical member according to the embodiment can effectively block external oxygen or moisture by the light conversion partition wall, and absorb the impact from the outside to prevent damage to the optical member.

In addition, since the light conversion partition also includes light conversion particles, the wavelength of the light source passing through the light conversion partition can also be converted, thereby improving color reproducibility and color uniformity of the liquid crystal display device.

Therefore, the optical member and the display device including the optical member according to the embodiment can have improved durability and reliability, and the partition of the liquid crystal display device is not only a light conversion part but also a partition wall including light conversion particles. There is an effect that can improve the reproducibility and color uniformity.

Features, structures, effects, and the like described in the above 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 the embodiments 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 (13)

A first substrate;
A light conversion barrier disposed on the first substrate; And
An optical member comprising a light conversion unit disposed in the light conversion partition. The optical member of claim 1, further comprising a second substrate disposed on the light conversion partition. The method of claim 2, wherein the first substrate is in direct contact with the lower surface of the light conversion partition,
And the second substrate is in direct contact with an upper surface of the light conversion partition. The optical member according to claim 1, wherein the light conversion partition includes a photocurable resin. The optical member of claim 1, wherein the light conversion partition includes light conversion particles for converting a wavelength of incident light. The method of claim 5, wherein the light conversion partition comprises a transparent polymer,
And the light conversion particles are disposed in the polymer. Light source;
A light conversion member on which light from the light source is incident; And
And a display panel on which light from the photo-conversion member is incident,
The light conversion member
A light conversion barrier including a plurality of accommodation portions;
A plurality of light conversion units disposed in the accommodation units, respectively; And
And a first substrate and a second substrate sandwiching the light conversion barrier and the light conversion units. The method of claim 7, wherein the light conversion partition wall
An isolation unit interposed between the first substrate and the second substrate and surrounding the light conversion units, respectively; And
And a plurality of first light conversion particles disposed in the isolation unit. The display device of claim 8, wherein the light conversion parts are in direct contact with inner surfaces of the accommodation parts. The method of claim 9, wherein the light conversion unit
A host disposed on an inner side of the accommodation portion; And
And a plurality of second light conversion particles disposed in the host. Coating a resin composition comprising a photocurable resin and a plurality of light conversion particles on the first substrate to form a resin composition layer,
A second substrate is laminated on the resin composition layer,
Selectively irradiating light to the resin composition layer to form a light conversion partition and a plurality of light conversion sections separated by the light conversion partition. The mask of claim 11, further comprising a mask including a transmission region corresponding to a region where the light conversion partition is formed on the second substrate,
The manufacturing method of the light conversion member which irradiates light to the said resin composition layer through the said mask. The method of claim 11, wherein the light conversion partition has a mesh shape.

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