KR102030839B1 - Difusion film for Back Light Unit and Manufacturing Method Thereof and Back Light Unit - Google Patents

Abstract

The present invention relates to a quantum dot integrated diffusion film for a backlight unit, a method of manufacturing the same, and a backlight unit having the same, wherein a plurality of quantum dots are disposed integrally on a diffusion film body for diffusing light transmitted from a light guide plate. Quantum dot film is integrated to reduce the volume of the backlight unit and to minimize light loss, to smoothly emit white light with fewer quantum dots compared to the existing quantum dot film, and to simplify the manufacturing process of the existing quantum dot film. Improve productivity of backlight unit and reduce manufacturing cost.

Description

Quantum dot integrated diffusion film for backlight unit and method for manufacturing same and backlight unit having same {Difusion film for Back Light Unit and Manufacturing Method Thereof and Back Light Unit}

The present invention relates to a quantum dot integrated diffusion film for a backlight unit, and more particularly, to provide a quantum dot layer including quantum dots integrally to simplify the manufacturing process of the backlight unit, and to contribute to a reduction in manufacturing cost, It relates to a manufacturing method and a backlight unit having the same.

In general, the backlight unit is a light source device that emits light behind a liquid crystal display such as a liquid crystal display (LCD), and uses a LED as a light source.

The backlight unit uses red (R) or green (G) fluorescent materials on a blue LED chip to emit white light when the LED is used as a light source.

Recently, referring to FIG. 1, a backlight unit for emitting white light using the quantum dot film 4 has been proposed.

The white light implemented through the quantum dot film 4 has an advantage of excellent color expression compared to the white light through a conventional blue LED chip and a fluorescent material, and thus the production of the backlight unit using the quantum dot film 4 is gradually increased.

The backlight unit is sequentially disposed on the light guide plate 1, the LED light source 2 disposed on the side of the light guide plate 1, the reflective plate 3 disposed below the light guide plate 1, and the upper part of the light guide plate 1. The laminated quantum dot film 4, the diffusion film 5, and the prism film 6 are configured to emit white light.

For example, when the LED light source 2 is a blue LED, a quantum dot film 4 including a quantum dot representing a color of red (R) and green (G) is used.

Referring to FIG. 2, the quantum dot film 4 includes a quantum dot layer 4a in which quantum dots are distributed and a barrier layer 4b covering upper and lower surfaces of the quantum dot layer 4a. The barrier layer 4b blocks water and air from entering the quantum dot layer 4a.

The quantum dot film 4 has a structure in which the barrier layer 4b is adhered to the upper and lower surfaces of the quantum dot layer 4a, respectively, so that a separate adhesive layer 4c is provided between the quantum dot layer 4a and the barrier layer 4b. ) And the adhesive layer (4c) has a problem of lowering the light transmittance and light efficiency, there is a problem that the manufacturing process is complicated and the manufacturing cost is high.

The quantum dot film 4 has a problem in that the quantum dot layer 4a is in contact with air and oxidized in the process of bonding the barrier layer 4b to the upper and lower surfaces after forming the quantum dot layer 4a. There is a problem of thickening.

In the quantum dot film 4, the quantum dots may be entangled or aggregated in the quantum dot layer 4a, thereby deteriorating the inherent characteristics of the quantum dots and frequently causing defects in which uniform light emission cannot be made. There is a problem in that the quantum dot layer 4a must include a larger amount of quantum dots than the quantum dots of the necessary reference value.

In addition, the production of the quantum dot film 4 separately, there is a difficulty in further manufacturing the process, causing a increase in the manufacturing cost of the backlight unit.

There is a problem in that the volume of the backlight unit is increased by using the quantum dot film 4 manufactured separately.

The present invention has been made in view of the above, and by quantum dots integrally formed in the diffusion film without using a separate quantum dot film, reducing the volume and thickness of the backlight unit, and simplify the manufacturing process of the backlight unit and In addition, an object of the present invention is to provide a quantum dot integrated diffusion film for a backlight unit and a method for manufacturing the same, which may contribute to a reduction in manufacturing cost.

Another object of the present invention is to provide a quantum dot integrated diffusion film for a backlight unit in which the quantum dots are uniformly dispersed by laminating and integrating the quantum dots on the diffusion film by an electrospinning or electrospray method and a method of manufacturing the same.

Still another object of the present invention is to provide a quantum dot integrated diffusion film for a backlight unit and a method of manufacturing the same, which do not require the use of a separate adhesive as in the prior art by laminating the barrier layer on the diffusion film in which the quantum dots are laminated. To provide.

Still another object of the present invention is to provide a backlight unit capable of realizing a display device having a clearer image quality by providing a quantum dot-integrated diffusion film as described above, which is thin in thickness, reduces manufacturing costs, and improves light transmittance and light efficiency. To provide.

A quantum dot integrated diffusion film for a backlight unit according to an embodiment of the present invention for achieving the above object, the diffusion film body for diffusing the light received from the light guide plate; And

And a quantum dot layer integrally stacked on the diffusion film body and having a plurality of quantum dots disposed therein.

The quantum dot integrated diffusion film for a backlight unit according to an embodiment of the present invention may further include a barrier layer integrally stacked on the quantum dot layer to cover the quantum dot layer.

In the present invention, the quantum dot layer may include a quantum dot in the polymer resin layer, and may be integrally formed in a fused shape on the diffusion film body.

The barrier layer may be a polymer resin layer and may be integrally formed by being fused on the quantum dot layer.

Method for manufacturing a quantum dot integrated diffusion film for a backlight unit according to an embodiment of the present invention for achieving the above object comprises the steps of preparing a diffusion film body for diffusing the received light; And

And integrating the quantum dot layer on the diffusion film body to integrate the quantum dot layer.

In the present invention, the step of stacking and integrating the quantum dot layer may use an electrospray or an electrospinning method.

In the present invention, forming the quantum dot layer by electrospraying or electrospinning may be formed by electrospraying or electrospinning the polymer resin solution containing the quantum dots on the diffusion film body.

In the present invention, forming the quantum dot layer by electrospraying or electrospinning is to form a quantum dot layer by spraying and dispersing the quantum dots separately on the diffusion film body while the polymer resin solution is electrosprayed or electrospun on the diffusion film body. can do.

The method of manufacturing a quantum dot integrated diffusion film for a backlight unit according to an embodiment of the present disclosure may further include stacking and integrating a barrier layer covering the quantum dot layer on the quantum dot layer.

In the present invention, in the step of stacking and integrating the barrier layer, the barrier layer may be formed by electrospraying or electrospinning the polymer resin solution.

In the present invention, in the step of stacking and integrating the barrier layer, the barrier layer may be formed in the form of a non-porous film through electrospraying on the quantum dot layer.

A backlight unit for achieving the object of the present invention, the light guide plate; An LED light source disposed on a side of the light guide plate; A reflection plate disposed under the light guide plate; And a quantum dot integrated diffusion film as described above stacked on the light guide plate.

According to the present invention, it is possible to reduce the volume and thickness of the backlight unit by eliminating the use of a quantum dot film that has been used separately and to integrate the quantum dot into the diffusion film, and to simplify the manufacturing process, thereby reducing the manufacturing cost of the backlight unit. There is a saving effect.

In addition, according to the present invention, since the quantum dots are laminated and integrated on the diffusion film by an electrospinning or electrospraying method, the quantum dots are uniformly dispersed to solve entanglement and agglomeration of the quantum dots as in the prior art, thereby inherent quantum dots. Efficient light emission of white light is possible according to characteristics, and even light emission is possible on the front of the display panel, thereby obtaining clearer picture quality.

In addition, according to the present invention, there is an effect of smoothly emitting white light with a smaller number of quantum dots than conventional quantum dot film according to the electrospinning of the quantum dots or the electrospray method.

In addition, the present invention can suppress the loss of light and the decrease in light transmittance caused by the use of the conventional adhesive by laminating the barrier layer to the quantum dot layer by electrospinning or electrospraying without attaching the barrier layer using the adhesive to the quantum dot film. It can maximize the light efficiency.

In particular, when applied to the backlight unit of a large-area display panel of 40 inches or more, it is possible to evenly emit light on the front of the display panel at a low manufacturing cost, thereby greatly improving the quality of the display panel.

1 is a schematic view showing a typical backlight unit
2 is a cross-sectional view showing a conventional quantum dot film
3 is a view illustrating an embodiment of a quantum dot integrated diffusion film for a backlight unit according to the present invention;
4 is a process chart showing a method for manufacturing a quantum dot integrated diffusion film for a backlight unit according to the present invention.
5 is a schematic view showing an embodiment of a method for manufacturing a quantum dot integrated diffusion film for a backlight unit according to the present invention;
6 is a schematic view showing an embodiment of a backlight unit according to the present invention;

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Here, the repeated description, well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention, and detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more completely describe the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for clarity.

The quantum dot integrated diffusion film for a backlight unit according to an exemplary embodiment of the present invention is disposed on the light guide plate to serve to diffuse light transmitted from the light guide plate. In addition, the light guide plate receives light of an LED light source disposed on a side surface and distributes light evenly over the entire screen area through a pattern deposited on a surface thereof.

Referring to FIG. 3, the quantum dot integrated diffusion film for a backlight unit according to an exemplary embodiment of the present invention may include a diffusion film body 10, which serves to diffuse light received from the light guide plate, and the diffusion film body 10. The quantum dot layer 21 may be integrally stacked on the quantum dot layer 21a and the quantum dot layer 21 may be disposed therein.

The diffusion film body 10 is manufactured in the same manner as the diffusion film used in the conventional backlight unit, it is an example to prevent light aggregation phenomenon by spreading the light transmitted from the light guide plate.

In addition, the quantum dot integrated diffusion film for a backlight unit according to an embodiment of the present invention, further comprising a barrier layer 22 which is integrally laminated on the quantum dot layer 21 to cover the quantum dot layer 21. desirable.

The quantum dot layer 21 and the barrier layer 22 form a quantum dot film, and the quantum dot film has a structure in which it is integrally laminated on the diffusion film, that is, the diffusion film body 10.

The barrier layer 22 covers one surface of the quantum dot layer 21 to block water from flowing into the quantum dot layer 21, and prevents the quantum dot layer 21 from being oxidized in contact with air. The polymer resin is preferably formed to have a non-porous form.

The barrier layer 22 is a material of any one of polycarbonate (PC) and poly (methylmethacrylate) (PMMA) having excellent transparency, polyvinylidene fluoride (PVDF) having excellent water resistance, or polycarbonate (PC) and poly (PMMA) methylmethacrylate)), PVDF (Polyvinylidene Fluoride) is preferably a mixed resin containing at least one.

The quantum dot layer 21 includes a quantum dot 21a inside the polymer resin layer, and the polymer resin layer is any one of polycarbonate (PC), poly (methylmethacrylate) (PMMA), and polyvinylidene fluoride (PVDF). For example, the material may be a mixed resin including at least one of polycarbonate (PC), poly (methylmethacrylate) (PMMA), and polyvinylidene fluoride (PVDF), and may be formed of the same polymer resin as the barrier layer 22. desirable.

The quantum dot layer 21 includes polystyrene (PS), expandable polystyrene (EPS), polyvinyl chloride (PVC), styrene acrylonitrile copolymer (SAN), polyurethane (PU), polyamide (PA), polyvinyl butyral (PVB), and PVAc. (Poly (vinyl acetate), acrylic resin (Acrylic Resin), epoxy resin (EP: Epoxy Resin), silicone resin (Silicone Resin), unsaturated polyester (UP: Unsaturated Polyester) and the like, may be formed of one of these, or It may be used by mixing two or more kinds, it should be noted that may be a synthetic resin containing at least one of these.

The quantum dots 21a are particles in which nano-sized II-IV semiconductor particles form a core. The fluorescence of the quantum dot 21a is light generated when electrons in an excited state fall from the conduction band to the valence band.

In an embodiment of the present invention, the quantum dot 21a may include any kind of semiconductor, such as group II-VI, group III-V, group IV-VI, group IV semiconductors, and mixtures thereof. The semiconductor is Si, Ge, Sn, Se, Te, B, C, P, BN, BP, BAs, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdxSeySz, CdTe, HgS, HgSe, HgTe, BeS, BeSe, BeTe, MgS, MgSe, Ge GeSe, GeTe, SnS, SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, CuInS2, Cu2SnS3, CuBr, CuI, Si3N4, Ge3N4, Al2O3, (Al, Ga, In) 2 (S, Se, Te) ), CIGS, CGS, (ZnS) y (CuxSn1-xS2) 1-y, or a mixed semiconductor in which at least two or more of these semiconductors are mixed. The quantum dot 21a may have a core / shell structure or an alloy structure, and non-limiting examples of the quantum dot 21a having the core / shell structure or the alloy structure may include CdSe / ZnS, CdSe / ZnSe / ZnS, and CdSe /. CdSx (Zn1-yCdy) S / ZnS, CdSe / CdS / ZnCdS / ZnS, InP / ZnS, InP / Ga / ZnS, InP / ZnSe / ZnS, PbSe / PbS, CdSe / CdS, CdSe / CdS / ZnS, CdTe / Note that there are CdS, CdTe / ZnS, CuInS2, / ZnS, Cu2SnS3 / ZnS and the like.

In the embodiment of the present invention, the quantum dot 21a is selected to form white light according to the light source color of the LED light source used in the corresponding backlight unit. For example, when the LED light source is a blue LED, the red ( A quantum dot 21a representing the color of R) and green G is selected and used.

The quantum dot layer 21 may include quantum dots 21a representing one or more colors selected from the group consisting of red light, green light, blue light, and yellow light. The quantum dots 21a may absorb ultraviolet light having a wavelength of about 100 to about 400 nm and visible light having a wavelength of about 380 to 780 nm. In the present specification, the blue light may have a light emission peak in the wavelength region of 410 nm or more and less than 500 nm, the green light may have a light emission peak in the wavelength region of 500 nm or more and less than 550 nm, and the yellow light of more than 550 nm and less than 600 nm It may have a light emission peak in the wavelength region, the red light may have a light emission peak in the wavelength region of 600nm or more and less than 660nm. In the present specification, for convenience, it is represented by four names such as blue, green, yellow, and red, but it should be noted that the wavelength region may include various colors such as orange, indigo, and violet in addition to these colors.

The quantum dot layer 21 may be integrally formed on the diffusion film body 10 in a fused form, and the barrier layer 22 may be fused on the quantum dot layer 21. That is, the quantum dot layer 21 may be fused on the diffusion film body 10 to be integrally formed.

In addition, the barrier layer 22 is fused on the quantum dot layer 21 and integrally formed.

Since the quantum dot layer 21 is formed to be directly integrated into the fused form on the diffusion film body 10, the barrier layer 22 is formed to be directly integrated into the fused form on the quantum dot layer 21 It is integrated with the diffusion film body 10 without a separate adhesive layer to simplify the manufacturing process, reduce the manufacturing cost and to form a thinner thickness of the backlight unit to reduce the volume of the backlight unit.

The quantum dot layer 21 should cover the upper and lower surfaces, respectively, in order to prevent oxidation due to contact with air and to prevent the penetration of moisture, and one surface of both surfaces is covered by the diffusion film body 10, The other layer is covered by the barrier layer 22 to prevent oxidation due to contact with air and to prevent moisture penetration.

Since the quantum dot film 20 according to another embodiment of the present invention is directly formed on the diffusion film body 10 in a fused shape, the barrier layer covering the quantum dot layer 21 is formed. By reducing the number of 22, the thickness of the backlight unit can be made slimmer, the manufacturing process is simplified and the manufacturing cost is further reduced.

Referring to FIG. 4, the method for manufacturing the quantum dot integrated diffusion film for the backlight unit may include preparing a diffusion film body 10 for diffusing the received light (S100); And

Integrating the quantum dot layer 21 on the diffusion film body 10 and integrating the same (S200).

The method may further include stacking and integrating the barrier layer 22 covering the quantum dot layer 21 on the quantum dot layer 21 (S300).

The diffusion film body 10 is manufactured in the same manner as the diffusion film used in the conventional backlight unit, it is an example to prevent light aggregation phenomenon by spreading the light transmitted from the light guide plate.

In the present invention, the quantum dot film 20 includes a quantum dot layer 21 stacked on the diffusion film body 10 and a barrier layer 22 stacked on the quantum dot layer 21, and the diffusion film body As an example, it is laminated and integrated on (10).

Referring to FIG. 5, in the step of stacking and integrating the quantum dot layer 21 (S200), it is preferable to form the quantum dot layer 21 by electrospraying or electrospinning.

In addition, in the step of stacking and integrating the barrier layer 22 (S200), the barrier layer 22 may be formed by electrospraying or electrospinning the polymer resin solution.

The quantum dot layer 21 is formed in a laminated structure by electrospinning or electrospraying on the diffusion film body 10 and is integrated in a form in which the quantum dot layer 21 is directly fused onto the diffusion film body 10 as an interface thereof.

In addition, the barrier layer 22 is formed in a laminated structure by electrospinning or electrospraying on the quantum dot layer 21 and integrated in a form in which the barrier layer 22 is directly fused onto the quantum dot layer 21 as an interface.

Since the diffusion film body 10, the quantum dot layer 21, and the barrier layer 22 are integrated in the form of being fused to each other by electrospray or electrospinning, separate adhesive layers for attaching to each other are not required.

Since the quantum dot layer 21 is fused by electrospraying or electrospinning on the diffusion film body 10, the quantum dot layer 21 is integrated on the diffusion film body 10 without a separate adhesive layer for attaching on the diffusion film body 10. do.

In the process of forming the barrier layer 22 by electrospraying or electrospinning, the barrier layer 22 may be formed by electrospraying or electrospinning, but it is more preferable to form the barrier layer 22 by electrospraying.

In the step of stacking and integrating the barrier layer 22 (S300), after forming a fiber layer through electrospinning on the quantum dot layer 21, the fiber layer may be non-porous using a residual solvent and heat. Deterioration of the quantum dot 21a may proceed by heat.

Therefore, in the step of stacking and integrating the barrier layer 22 (S300), it is preferable to form the barrier layer 22 in the form of a non-porous film through the electrospray on the quantum dot layer 21.

In addition, the step of stacking and integrating the barrier layer 22 (S300) may be a resin solution of any one of polycarbonate (PC), poly (methylmethacrylate) (PMMA), and polyvinylidene fluoride (PVDF), or polycarbonate (PC). ), A mixed resin solution including at least one of poly (methylmethacrylate) (PMMA) and polyvinylidene fluoride (PVDF) is electrosprayed or electrospun to form a barrier layer 22 in the form of a non-porous membrane.

Forming the quantum dot layer 21 by the electrospray or electrospinning may be formed by electrospraying or electrospinning the polymer resin solution containing the quantum dot (21a) on the diffusion film body 10, the polymer resin solution The quantum dot layer 21 may be formed by separately spraying and dispersing the quantum dots 21a on the diffusion film body 10 during electrospraying or electrospinning on the diffusion film body 10.

The polymer resin solution is preferably the same as the polymer resin solution forming the barrier layer 22. Embodiments of the polymer resin and the quantum dot 21a forming the quantum dot layer 21 will be omitted as a redundant description as described above.

Since the quantum dot layer 21 is formed by electrospraying or electrospinning, dispersion of the quantum dots 21a is made evenly and uniformly on the layer to solve the entanglement and agglomeration of the quantum dots 21a in the existing quantum dot film.

The quantum dot layer 21 is cured when formed on the diffusion film body 10 by the electrospray or electrospinning, and forming the quantum dot layer 21 by electrospraying or electrospinning is residual solvent in the polymer resin. Note that a separate heat curing process may be added to remove the.

The barrier layer 22 is cured when formed on the quantum dot layer 21 by the electrospray or electrospinning, and the process of forming the barrier layer 22 by the electrospray or electrospinning (S230) Note that a separate heat cure process may be added to remove residual solvent in the furnace.

Referring to FIG. 6, a backlight unit according to an exemplary embodiment of the present invention may include a light guide plate 1, an LED light source 2 disposed on a side surface of the light guide plate 1, and a reflector plate disposed below the light guide plate 1. (3) and the above-mentioned quantum dot integrated diffusion film for a backlight unit which is laminated on the light guide plate 1.

The backlight unit according to an embodiment of the present invention may further include a prism film 6 laminated on the quantum dot integrated diffusion film for the backlight unit.

According to the present invention, it is possible to reduce the volume and thickness of the backlight unit by eliminating the use of a quantum dot film that has been used separately and to integrate the quantum dot into the diffusion film, and to simplify the manufacturing process, thereby reducing the manufacturing cost of the backlight unit. Can be saved.

In addition, according to the present invention, since the quantum dots are laminated and integrated on the diffusion film by an electrospinning or electrospraying method, the quantum dots are uniformly dispersed to solve entanglement and agglomeration of the quantum dots as in the prior art, thereby inherent quantum dots. Efficient light emission of white light is possible according to characteristics, and even light emission is possible on the front of the display panel, thereby obtaining clearer picture quality.

In addition, according to the present invention, white light can be smoothly emitted with fewer quantum dots than conventional quantum dot films according to the electrospinning or electrospraying of quantum dots.

In addition, the present invention can suppress the loss of light and the decrease in light transmittance caused by the use of the conventional adhesive by laminating the barrier layer to the quantum dot layer by electrospinning or electrospraying without attaching the barrier layer using the adhesive to the quantum dot film. It can maximize the light efficiency.

In particular, when applied to the backlight unit of a large-area display panel of 40 inches or more, it is possible to evenly emit light on the front of the display panel at a low manufacturing cost, thereby greatly improving the quality of the display panel.

Within the scope of the basic technical idea of the present invention, many other modifications are possible to those skilled in the art, and the scope of the present invention should be interpreted based on the appended claims. will be.

10: diffusion film body 20: quantum dot film
21: quantum dot layer 21a: quantum dot
22: barrier layer

Claims (12)

A diffusion film body disposed on the light guide plate to diffuse light transmitted from the light source through the light guide plate;
A quantum dot layer having a plurality of quantum dots disposed integrally by electrospraying or electrospinning on the diffusion film body; And
And a barrier layer integrally stacked on the quantum dot layer to cover the quantum dot layer.
The quantum dot layer and the barrier layer is the same material and the quantum dot integrated diffusion film for a backlight unit, characterized in that laminated in the form of direct fusion in the form of a non-porous film by electrospinning or electrospraying. delete The method of claim 1,
The quantum dot layer, the quantum dot is included in the polymer resin layer, the quantum dot integrated diffusion film for a backlight unit, characterized in that formed integrally in the form fused on the diffusion film body. The method of claim 1,
The barrier layer is a polymer resin layer, the quantum dot integrated diffusion film for a backlight unit. Preparing a diffusion film body disposed on the light guide plate to diffuse light transmitted from the light source to the light guide plate;
Stacking and integrating a quantum dot layer on the diffusion film body; And
Stacking and integrating a barrier layer covering the quantum dot layer on the quantum dot layer;
Stacking and integrating the quantum dot layer using an electrospray or electrospinning method,
The quantum dot layer and the barrier layer is the same material and is laminated in a form that is directly fused in the form of a non-porous film by electrospinning or electrospraying. delete The method of claim 5,
Forming the quantum dot layer by electrospraying or electrospinning is a method of manufacturing a quantum dot integrated diffusion film for a backlight unit, characterized in that the polymer resin solution containing the quantum dots is formed by electrospraying or electrospinning on the diffusion film body. The method of claim 5,
Forming the quantum dot layer by the electrospray or electrospinning is characterized in that to form a quantum dot layer by spraying and dispersing the quantum dots separately on the diffusion film body during the electrospray or electrospinning of the polymer resin solution on the diffusion film body A quantum dot integrated diffusion film manufacturing method for a backlight unit. delete The method of claim 5,
Stacking and integrating the barrier layer may include:
A method of manufacturing a quantum dot integrated diffusion film for a backlight unit, wherein the polymer resin solution is electrosprayed or electrospun to form a barrier layer. delete Light guide plate;
An LED light source disposed on a side of the light guide plate;
A reflection plate disposed under the light guide plate; And
And a quantum dot integrated diffusion film according to any one of claims 1 and 3 to 4 stacked on the light guide plate.

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