KR101148119B1 - Back light unit within resin layer for light-guide and LCD using the same - Google Patents

Abstract

The present invention relates to a structure of a backlight unit, comprising: a plurality of LED light sources formed on a printed circuit board, a resin layer diffusely inducing light emitted from the LED light source, a reflective film formed on an upper surface of the printed circuit board; At least one reflective pattern printed on the reflective film is characterized in that it comprises at least one.
According to the present invention, it is possible to realize the shape of the reflection pattern in three-dimensional three-dimensional shape by using the difference in printing power in the LED light output direction in the LED backlight unit, and use a variety of materials for each printing frequency (number of layers) It can maximize the effect of the reflection pattern, while increasing the frequency of printing as it moves away from the LED light emitting part, and can extract light from the dark part lost inside as much as possible to improve the light uniformity. It works.

Description

Back light unit within resin layer for light-guide and LCD using the same}

The present invention relates to a backlight unit capable of thinning the structure of a backlight unit by removing the structure of the light guide plate and securing a light efficiency and a liquid crystal display device using the same.

A liquid crystal display (LCD) is a display device that can control a desired image by individually supplying data signals according to image information to pixels arranged in a matrix form and adjusting light transmittance of the pixels. Since it does not emit light, it is designed to display an image by installing a back-light unit on its back side.

Referring to FIG. 1A, in the backlight device 1, a flat light guide plate 30 is disposed on a substrate 20, and a plurality of side type LEDs 10 (only one) are disposed on the side of the light guide plate 30. Is placed.

The light L incident from the LED 10 to the light guide plate 30 is reflected upward by a minute reflection pattern or a reflective sheet 40 provided on the bottom surface of the light guide plate 30, and exits from the light guide plate 30. 30) the backlight is provided to the upper LCD panel 50. In the backlight unit, as shown in FIG. 1B, a plurality of optical devices, such as a diffusion sheet 31, a prism sheet 32 and 33, a protective sheet 34, and the like are disposed between the light guide plate 30 and the LCD panel 50. It can be formed into a structure for further adding a sheet.

The backlight unit serves to evenly illuminate the display image on the back of the LCD which does not emit light itself, and the light guide plate is a component that performs brightness and uniform illumination of the backlight unit. It is one of the plastic molded lenses that uniformly transmits the emitted light to the entire LCD surface. Therefore, such a light guide plate is basically used as an essential component of such a backlight unit, but because of this, the thickness of the entire product can be reduced due to the thickness of the light guide plate itself. Is causing.

The present invention has been made to solve the above-described problems, an object of the present invention can be implemented in a three-dimensional three-dimensional shape of the reflective pattern by using the difference in the printing frequency in the LED light output direction in the LED backlight unit. Various materials can be used for each printing frequency (layers) to maximize the effect of the reflection pattern, while increasing the printing power as the LED light is farther away. It is to provide a backlight unit that can be extracted to the outside to improve the light uniformity.

In particular, the number of light sources can be reduced, the overall thickness of the backlight unit can be reduced, and the product design can be reduced by removing the light guide plate essential to the structure of the backlight unit and forming a structure that induces the light source using a film type resin layer. Another object of the present invention to provide a backlight unit that can increase the degree of freedom.

The present invention is a plurality of LED light source formed on a printed circuit board to solve the above problems; A resin layer for inducing diffusion of light emitted from the LED light source to the front; A reflective film formed on an upper surface of the printed circuit board; And it is possible to provide a backlight unit having at least one or more reflective patterns printed on the reflective film.

In particular, the reflection pattern is preferably disposed so that the lamination frequency increases as the distance from the LED light source.

In addition, the reflective pattern may be formed by applying a reflective ink including any one of TiO ₂ , CaCO ₃ , BaSO ₄ , Al ₂ O ₃ , Silicon, and poly stylen (PS).

Further, the unit reflection patterns constituting the reflective pattern according to the present invention may be formed of different materials, and the unit reflection pattern may have a thickness of 5 μm to 100 μm.

The backlight unit may include an optical pattern disposed on the resin layer; And a diffuser plate disposed on the optical pattern.

Alternatively, the optical pattern of the backlight unit according to the present invention may be disposed under the transparent substrate, and the diffusion plate may be disposed on the transparent substrate.

The method further includes an optical pattern layer including a first substrate and a second substrate including the optical pattern therein, the optical pattern layer including the first air region surrounding a periphery of the optical pattern. It may be implemented to be formed on the optical pattern layer. In this case, an air gap module having a second air region may be further provided between the optical pattern layer and the diffusion plate.

The resin layer according to the present invention may further comprise a bead (bead) to increase the reflection of light compared to the total resin layer 0.01 ~ 0.3%.

Above the optical pattern according to the present invention can be of a light-shielding pattern formed of a material containing any one or more materials _{TiO 2, CaCO 3, BaSO 4} , Al 2 O 3, selection of the Silicon, PS.

The backlight unit according to the present invention may further include a prism sheet or a protective sheet stacked on the diffusion plate.

Of course, the liquid crystal display device may be manufactured using the backlight unit according to the present invention.

According to the present invention, it is possible to realize the shape of the reflection pattern in three-dimensional three-dimensional shape by using the difference in printing power in the LED light output direction in the LED backlight unit, and use a variety of materials for each printing frequency (number of layers) It can maximize the effect of the reflective pattern, while increasing the frequency of printing as it moves away from the LED light emitting part, and can extract light from the dark part lost inside as much as possible to improve the light uniformity. It works.

In particular, the number of light sources can be reduced, the overall thickness of the backlight unit can be reduced, and the product design can be reduced by removing the light guide plate essential to the structure of the general backlight unit and forming a structure that guides the light source using a film type resin layer. There is an effect that can increase the degree of freedom.

In addition, by mounting the side-type light emitting diode in a direct type, it is possible to secure the optical characteristics while significantly reducing the number of light sources, it is also applicable to the structure of the flexible display by removing the light guide plate, the reflective film including a reflective pattern in the resin layer And it is also provided with a diffusion plate including an air layer has the effect of ensuring a stable light emission characteristics.

In addition, the optical pattern layer having the light shielding pattern layer and the air region surrounding the air gap module or the air gap module having the air layer can be provided, thereby increasing the optical characteristics of the backlight unit and the light uniformity. have.

1A and 1B are conceptual views illustrating a structure of a backlight unit according to the prior art.
2 is a conceptual view illustrating main parts of a backlight unit according to the present invention.
3 is a conceptual diagram illustrating an embodiment in which an arrangement structure of reflective patterns according to the present invention is implemented.
4 illustrates an embodiment in which an arrangement structure of an optical pattern according to the present invention is implemented.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation according to the present invention. In the description with reference to the accompanying drawings, the same components are given the same reference numerals regardless of the reference numerals, and duplicate description thereof will be omitted. The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The present invention includes a resin layer that removes the light guide plate from the structure of the conventional backlight unit and replaces the light guide plate, and realizes the shape of the reflective pattern three-dimensionally by using the difference in the printing frequency in the LED light emission direction. Summary of the Invention It is an object of the present invention to provide a structure for securing light uniformity and realizing thickness reduction.

2 conceptually illustrates a cross-sectional view of a backlight unit according to the present invention.

Referring to the drawings, the backlight unit according to the present invention includes a plurality of LED light sources 130 formed on the printed circuit board 110, and further, the light emitted from the LED light source 130 on the printed circuit board. It is provided with a resin layer 140 to induce diffusion to the front. In addition, at least one reflective film 120 formed on the upper surface of the printed circuit board and at least one reflective pattern 121 printed on the reflective film is provided.

Of course, in this case, the reflective film 120 on the upper surface of the printed circuit board may have a groove through which the LED can penetrate, the diffusion plate 170 formed on the resin layer 140 and the The optical pattern 150 may be further included between the resin layer and the diffusion plate. In addition, a prism sheet, a protective sheet, etc. may be additionally provided on the diffusion plate.

In particular, referring to FIG. 3, this is a conceptual diagram illustrating an arrangement of the reflective pattern 121 according to the present invention. The reflective pattern 121 according to the present invention may be printed in a multi-layered structure on the reflective film in the light output direction of the LED light source 130. That is, the reflective pattern 121 may be arranged with at least one pattern having a structure in which at least two layers are stacked through white printing. Preferably, as shown in the drawing, the reflective pattern is further away from the LED light source. It can arrange | position so that lamination frequency may become large. For example, the reflective pattern 121a of the one-layer structure, the reflective pattern 121b of the two-layer structure, the reflective pattern 121c of the three-layer structure, and the reflective pattern 121d of the four-layer structure are arranged in a structure having a predetermined interval. can do. Of course, in the present example, the arrangement of the printing structure of 4 degrees is taken as an example, but the arrangement of the reflective pattern as the printing structure of 2 degrees or more may be variously formed according to the shape or material change. As the printing method of the reflective pattern, various printing methods such as gravure printing and silk screen printing may be applied. In addition, the reflective pattern may be printed by applying a reflective ink containing any one of TiO ₂ , CaCO ₃ , BaSO ₄ , Al ₂ O ₃ , Silicon, and PS (Poly Stylen).

In addition, each of the printing layers constituting the reflective pattern 121 (hereinafter, referred to as a “unit reflection pattern”) may be formed of different materials, and the unit reflection pattern may have a thickness of 5 μm to 100 μm. It may be provided.

The structure of the reflective pattern according to the present invention, by applying a gradient to the reflective pattern using the difference in the printing frequency can act to improve the light uniformity by extracting the light lost from the inside as much as possible. Will be. Specifically, the printing of the reflective pattern of a simple 1 degree (one layer structure) has a limitation that the pattern shape can adjust the light uniformity only in two dimensions and that only one material can be applied, but the reflective pattern according to the present invention has the shape This three-dimensional three-dimensional shape can be realized and various materials can be used as a printing method to maximize the effect of the reflection pattern. Furthermore, as the arrangement of the reflective pattern increases away from the LED light emitting part, the light intensity of the dark part can be extracted to the outside as much as possible, which can greatly improve the light uniformity. Of course, after the formation of the reflective pattern according to the present invention may further form a special coating layer such as primer (primer) treatment.

Hereinafter, the structure and operation of the backlight unit according to the present invention in which the adjustment of the emission angle of the above-described structure is implemented will be described in detail with reference to the configuration of FIGS. 2 and 3.

Hereinafter, the structure and operation of the backlight unit with a diffuser plate according to the present invention having the microarray pattern having the above-described structure will be described in detail with reference to the configuration of FIG. 2.

As shown in FIG. 2, the LED light source 130 is arranged on the printed circuit board 110 in at least one number and emits light. In a preferred embodiment of the present invention, a side view LED is shown. Can be used. That is, the direction of the light emitted from the LED light source 130 may not use the light source having a structure that is directed toward the side rather than going straight upward. In addition, the arrangement method is arranged in a direct type using a side type light emitting diode, and while reducing the total number of light sources by using the resin layer 140 and the diffusion plate 170 to implement light diffusion and reflection functions. It is possible to innovatively reduce the thickness of the entire backlight unit.

The resin layer 140 is stacked in a structure surrounding the LED light source 130 to perform a function of dispersing light of the light source emitted laterally. That is, the resin layer 140 may perform a function of the conventional light guide plate. It is needless to say that the resin layer can be basically made of any resin capable of diffusing light. For example, the main material of the resin layer according to one embodiment of the present invention may be a resin having urethane acrylate oligomer as a main material. For example, a mixture of urethane acrylate oligomer, which is a synthetic oligomer, with a polymer type of polyacrylic can be used. Of course, it may further comprise a monomer mixed with a low-boiling-point diluent type reactive monomer such as isobornyl acrylate (IBOA), hydroxypropyl acrylate (HPA), or 2-hydroxyethyl acrylate (HPA). A photoinitiator -hydroxycyclohexyl phenyl-ketone) or an antioxidant.

The resin layer 140 may include beads 141 to increase diffusion and reflection of light. Preferably, the bead comprises 0.01 to 0.3% by weight of the total resin layer. That is, the light emitted laterally from the LED is diffused and reflected through the resin layer 140 and the bead 141 to proceed upwards, and the reflective film 120 and the reflective pattern 121 to be described later When provided, this reflection function can be further promoted. The presence of the resin layer innovatively reduces the thickness occupied by the conventional light guide plate, thereby realizing thinning of the entire product, as well as having a soft material, and thus having a versatility applicable to a flexible display. do.

In particular, an optical pattern 151 may be provided on the resin layer 140. In the embodiment illustrated in FIG. 2, an embodiment in which the optical pattern 151 is implemented under the diffusion plate 170 is illustrated. Shown. Specifically, the optical pattern is preferably formed as a light shielding pattern so that a part of the light shielding effect can be implemented in order to prevent the phenomenon that the light is excessively strong, so that the optical characteristics deteriorate or yellowish light is emitted. That is, the light shielding pattern may be printed using the light shielding ink so that light does not concentrate. The optical pattern may not be a function of completely blocking light, but may be implemented to control light blocking degree or diffusing degree of light with one optical pattern to perform a function of partially blocking and diffusing light. Furthermore, more preferably, the optical pattern according to the present invention may be implemented as a superimposed printed structure of a complex pattern. The superimposed printing structure refers to a structure that forms one pattern and prints another pattern shape on the upper portion thereof.

For example, in implementing the optical pattern 151, a light shielding ink including any one or more materials selected from TiO ₂ , CaCO ₃ , BaSO ₄ , Al ₂ O ₃ , and Silicon on the bottom surface of the polymer film in the light emitting direction It can be implemented as a superimposed printing structure of the light shielding pattern using a diffusion pattern formed by using a, and a light shielding ink containing Al or a mixture of Al and TiO ₂ . That is, after the diffusion pattern is formed on the surface of the polymer film by white printing, the light shielding pattern may be formed thereon, or in the reverse order, the double structure may be formed. Of course, it will be apparent that the patterned design of the pattern may be variously modified in consideration of light efficiency, intensity, and light blocking rate. Alternatively, in the sequential layer structure, a light shielding pattern, which is a metal pattern, may be formed on the middle layer, and a triple structure may be formed on the upper and lower portions thereof to implement a diffusion pattern, respectively. In such a triple structure, it is possible to select and implement the above-described materials. As a preferred example, one of the diffusion patterns is implemented using TiO ₂ having excellent refractive index, and CaCO ₃ having excellent light stability and color sense is used together with TiO _2. It is possible to realize different diffusion patterns, and to secure light efficiency and uniformity through the triple structure of the structure implementing the light shielding pattern using Al having excellent concealment. In particular, CaCO ₃ functions to subtract the exposure of yellow light to finally implement white light, thereby realizing more stable light. In addition to CaCO ₃ , particles such as BaSO ₄ , Al ₂ O ₃ , and silicon beads Larger, similarly structured inorganic materials may be used.

In addition, it is preferable in view of light efficiency that the optical pattern is formed by adjusting the pattern density so that the pattern density is lowered away from the emitting direction of the LED light source.

4 illustrates another embodiment of forming the above-described optical pattern.

As shown in the illustrated structure, the optical pattern 151 is printed in the above-described manner, and the same is formed in various ways. It is also possible to arrange).

That is, in particular, the optical pattern 151 formed on the resin layer 140 includes a first substrate 150A and a second substrate 150B including the optical pattern 151 therein. And an adhesive layer 153 applied to a portion other than the first air region 152 surrounding the peripheral portion of the optical pattern 151. As the first substrate 150A and the second substrate 150B, a substrate made of a material having excellent light transmittance may be used. For example, PET may be used. The optical pattern 151 disposed between the first substrate 150A and the second substrate 150B basically serves to prevent the light emitted from the LED light source from being concentrated, and the first substrate 150A. Alternatively, the second substrate 150B may be implemented through light shielding printing, and the two layers may be bonded to each other by an adhesive layer for applying an adhesive material in a structure surrounding the periphery of the light shielding pattern. That is, the adhesive structure of the first substrate 150A and the second substrate 150B may be implemented together with the function of fixing the printed light shielding pattern 151. In addition, as the adhesive layer, a thermosetting PSA, a thermosetting adhesive, or a UV curing PSA type material may be used.

In addition, a structure including an air layer (second air region) 160 between the optical pattern layer 150 and the diffusion plate 170 may be added to the configuration of the backlight unit according to the present invention. Due to the presence of 160, the effect of diffusing the light emitted from the light source and improving the uniformity of the light is realized. In addition, in order to minimize the deviation of the light transmitted through the resin layer 140 and the optical pattern layer 150, the thickness of the second air region 160 is preferably formed to be 0.01 ~ 2mm. The second air region 160 may be formed by implementing a structure capable of forming an air layer under the diffusion plate, and defined as an “air gap module” including a second air region implemented through such a structure. do. The air gap module includes both a method of realizing an air region (air layer) by processing the diffusion plate itself, or a configuration of forming an air region by forming a separate structure under the diffusion plate.

The backlight unit according to the present invention described above may be applied to the LCD through the following configuration and operation. Referring to FIGS. 2 and 3, light is emitted laterally from the side-emitting LED 130, and the emitted light is reflected and diffused from the resin layer 140 formed instead of the structure of the conventional light guide plate. It is possible to prevent the concentration of light through the layer 150 and minimize the deviation of light through the second air region 160 formed under the diffusion plate. In particular, the light emitted by the reflecting film 120 and the reflecting pattern 121 formed in a batch which increases the printing frequency as it moves away from the LED light source minimizes its disappearance and further increases the reflecting efficiency. It can be guided forward.

The light passing through the resin layer 140 is subjected to a process of being diffused or shielded through the optical pattern 151 formed on the optical pattern layer 150, and thus the purified light is formed in the lower portion of the diffuser plate. Once again through the optical properties can be purified uniformity can be increased. In addition, white light is incident on the LCD panel via an optical sheet such as a prism sheet and DBEF.

As described above, the backlight unit according to the present invention removes the structure of the light guide plate, applies a side light-emitting LED as a light source, diffuses light through the resin layer, and induces light through reflection, thereby reducing the thickness and the number of light sources. On the other hand, the brightness reduction and uniformity problems caused by the reduction of the light source increase the reflection as the distance from the light source increases the reflection pattern of the superimposed printed structure as the distance from the light source increases the stacking frequency to increase the light lost inside You can do this as much as possible. In addition, the light shielding pattern and the air region of the air gap module are provided to adjust the uniformity of light.

In the foregoing detailed description of the present invention, specific examples have been described. However, various modifications are possible within the scope of the present invention. The technical idea of the present invention should not be limited to the embodiments of the present invention but should be determined by the equivalents of the claims and the claims.

110: printed circuit board
120: reflective film
121: reflection pattern
121a ~ 121d: reflection pattern
130: light source
140: Resin layer
150: optical pattern layer
151: optical pattern
152: first air area
153: adhesive layer
160: second air area
170: diffuser plate

Claims (13)

A plurality of LED light sources formed on the printed circuit board;
A resin layer in close contact with the LED light source and diffusing the light emitted by being laminated on the printed circuit board to the front in a structure in which the LED light source is embedded;
A reflective film formed on an upper surface of the printed circuit board; And
A backlight unit having at least one or more reflective patterns printed on the reflective film.
The method according to claim 1,
And the reflection pattern is disposed such that the stacking degree increases as the distance from the LED light source increases.
The method according to claim 2,
The reflective pattern is formed by applying a reflective ink including any one of TiO ₂ , CaCO ₃ , BaSO ₄ , Al ₂ O ₃ , Silicon, PS (Poly Stylen).
The method according to claim 3,
The unit reflection patterns constituting the reflection pattern are formed of different materials from each other.
The method of claim 4,
The unit reflection pattern has a thickness of 5㎛ ~ 100㎛.
6. The method according to any one of claims 1 to 5,
An optical pattern disposed on the resin layer;
And a diffuser plate disposed on the optical pattern.
The method of claim 6,
The optical pattern is disposed below the transparent substrate,
And a diffuser plate disposed on the transparent substrate.
The method of claim 6,
Further comprising an optical pattern layer having a first substrate and a second substrate including the optical pattern therein,
And the optical pattern layer is formed on the optical pattern layer including a first air region surrounding a peripheral portion of the optical pattern.
The method according to claim 8,
And an air gap module having a second air region between the optical pattern layer and the diffusion plate.
The method of claim 6,
The resin layer,
It further includes a bead that increases the reflection of light,
The bead is a backlight unit 0.01 to 0.3% of the weight of the total resin layer is included on the resin layer.
The method of claim 6,
The optical pattern is
TiO ₂ , CaCO ₃ , BaSO ₄ , Al ₂ O _{3 It} is formed as a diffusion pattern formed using a light shielding ink containing any one or more materials selected from silicon or two or more mixtures,
A backlight unit embodied by a superimposed printing structure of a light shielding pattern formed of a light shielding ink including the diffusion pattern and Al or Al mixed with TiO ₂ .
The method of claim 11,
The backlight unit,
And a prism sheet or a protective sheet stacked on the diffusion plate.
A liquid crystal display device comprising the backlight unit of any one of claims 1 to 5.

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