KR101211728B1 - Back light unit within resin layer for light-guide and LCD using the same - Google Patents

Abstract

The present invention relates to a backlight unit, and in particular, a plurality of LED light sources formed on a printed circuit board and a resin layer for diffusing the emitted light forward, and disposed on the resin layer and surrounding the periphery of the optical pattern. It may be configured to include an optical pattern layer having a first air region.
According to the present invention, it is possible to include an air gap module having an air layer by patterning the optical pattern layer or the diffusion plate having the light shielding pattern layer and the air region surrounding the light emitting plate or by using a separate member, thereby providing a backlight unit. Diffusion and optical uniformity of the optical properties can be increased.
In addition, 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 a light guide plate essential to the structure of a general backlight unit and forming a structure that induces a light source using a film type resin layer. It is effective to increase the degree of freedom.

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 problems, an object of the present invention is to remove the light guide plate essential to the structure of a general backlight unit, and to form a structure to guide the light source using a film-type resin layer, To reduce the weight, reduce the overall thickness of the backlight unit, and to provide a backlight unit that can increase the degree of freedom of product design.

In addition, it is possible to provide an air gap module having an air layer by patterning the optical pattern layer or the diffusion plate having the light shielding pattern layer and the air region surrounding the light emitting layer, or by using a separate member, Another object of the present invention is to provide a backlight unit capable of increasing optical uniformity of optical uniformity.

The present invention provides a means for solving the above problems, a plurality of LED light source formed on a printed circuit board; and a resin layer for diffusing the emitted light forward; And an optical pattern layer disposed on the resin layer and having a first air region surrounding a peripheral portion of the optical pattern.

The optical pattern layer may include a first substrate and a second substrate including the optical pattern therein; And an adhesive layer applied to portions other than the first air region surrounding the peripheral portion of the optical pattern.

In addition, the present invention may implement a backlight unit further comprising a diffusion plate stacked on the optical pattern layer.

In particular, the present invention may be implemented in a structure in which an air gap module having a second air region is further provided between the optical pattern layer and the diffusion plate.

Or, as a configuration example slightly different from the above-described basic structure, a plurality of LED light sources formed on the printed circuit board; and a resin layer for diffusing the emitted light forward; An optical pattern layer disposed on the resin layer and having an optical pattern; A diffusion plate stacked on the optical pattern layer; The backlight unit may further include an air gap module having a second air region between the optical pattern layer and the diffusion plate.

The optical pattern layer having such a structure may have an optical pattern formed under the transparent substrate and include a first air region surrounding a periphery of the optical pattern.

Alternatively, the optical pattern layer may alternatively include a first substrate and a second substrate including the optical pattern therein; And an adhesive layer applied to portions other than the first air region surrounding the peripheral portion of the optical pattern.

Whatever the structure of the backlight unit, the air gap module according to the present invention may have a thickness of 0.01 ~ 2mm, further, the air gap module, by patterning the lower portion of the diffusion plate to form a second air region and the bridge It may be formed as an integrated structure implemented, or may be formed as a structure having a second air region by forming a bridge with an independent spacer member under the diffusion plate.

As the adhesive layer for bonding the first and second substrates, a thermosetting PSA, a thermosetting adhesive, or a UV curing PSA type material may be used.

The backlight unit according to the present invention may further include a reflective film having a reflective pattern laminated on the printed circuit board on the upper surface. In this case, the reflective pattern may include TiO ₂ , CaCO ₃ , BaSO ₄ , and Al. It may be formed by applying a reflective ink including any one of ₂ O ₃ , Silicon, PS.

In addition, the resin layer may be configured to further include a bead (bead) to increase the reflection of light compared to the total resin layer 0.01 ~ 0.3%.

In addition, the optical pattern may be implemented as a light shielding pattern formed of a material containing at least one material selected from TiO ₂ , CaCO ₃ , BaSO ₄ , Al ₂ O ₃ , Silicon, and PS.

Furthermore, the backlight unit may further include a prism sheet or a protective sheet stacked on the diffusion plate.

A resin layer laminated using a light emitting diode having a structure described above as a light source and accommodating the light source; An optical pattern layer disposed on the resin layer and having a first air region surrounding a periphery of the optical pattern; And it will be apparent that the backlight unit according to the present invention having a diffusion plate disposed on the optical pattern layer can be applied to the liquid crystal display device.

According to the present invention, it is possible to include an air gap module having an air layer by patterning the optical pattern layer or the diffusion plate having the light shielding pattern layer and the air region surrounding the light emitting plate or by using a separate member, thereby providing a backlight unit. Diffusion and optical uniformity of the optical properties can be increased.

In addition, 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 a light guide plate essential to the structure of a general backlight unit and forming a structure that induces a light source using a film type resin layer. It is effective to increase the degree of freedom.

In particular, 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, and can be applied to the structure of the flexible display by removing the light guide plate, and a reflective film including a reflective pattern in the resin layer And it is also provided with a diffuser plate including an air layer has the effect of ensuring a stable light emission characteristics.

1A and 1B are conceptual views illustrating a structure of a backlight unit according to the prior art.
2 and 3 are conceptual views illustrating main parts of a backlight unit according to the present invention.
4 is a conceptual diagram showing an embodiment of the air gap module according to the present invention.
5 is a layout view of an LED light source according to the present invention.

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.

According to the present invention, an optical gap layer including a light shielding pattern layer and an air region surrounding the optical pattern layer or a diffuser plate in the structure of a conventional backlight unit or an air gap module including an air layer using a separate member are provided to provide optical It is an object of the present invention to provide a structure capable of improving the characteristics, and in particular, removing the light guide plate and forming the resin layer to innovatively reduce the overall thickness of the backlight unit while reducing the number of light sources.

2 and 3 conceptually illustrate a cross-sectional view of the backlight unit according to the present invention.

Referring to the drawings, the backlight unit according to the present invention, the plurality of LED light source 130 formed on the printed circuit board 110 and the resin layer 140 to induce the diffusion of the light emitted from the LED light source to the front. And an optical pattern layer 150 disposed on the resin layer 140 and having a first air region 152 surrounding the periphery of the light shielding pattern 151.

Of course, in this case, the reflective film 120 may be stacked on the upper surface of the printed circuit board, and the diffusion plate 170 may be provided on the resin layer 140. An air gap module having a second air region 160 may be further provided between the optical pattern layer 150 and the optical pattern layer and the diffusion plate. In addition, a prism sheet, a protective sheet, and the like may be additionally provided on the diffusion plate.

The LED light source 130 is arranged on the printed circuit board 110 by at least one or more numbers to emit light, in a preferred embodiment of the present invention can use a side view LED (side view LED). 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 layout method is arranged in a direct type by using a side type light emitting diode, and by utilizing a resin layer that implements light diffusion and reflection functions, the total thickness of the backlight unit can be innovatively reduced while reducing the total number of light sources. Will be.

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.

In addition, as shown in FIG. 3, the resin layer 140 may include a bead 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, the optical pattern layer 150 formed on the resin layer 140 may have various structures having an optical pattern.

In the structure of the illustrated figure, the arrangement of the optical pattern 151 may be formed in a structure printed under one transparent substrate, and the optical pattern is disposed between the two substrates, and as shown here, the periphery of the pattern It is also possible to form it in the structure provided with an air layer.

In the latter embodiment, the optical pattern layer 150 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. In other words, the adhesive structure of the first substrate 150A and the second substrate 150B can also function to fix the printed light-shielding pattern 151. The adhesive layer may be a thermosetting PSA, a thermosetting adhesive, or a UV cured PSA type material.

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 containing at least one material selected from the group consisting of TiO ₂ , CaCO ₃ , BaSO ₄ , Al ₂ O ₃ , and Silicon on the lower surface of the polymer film in the light- And a light-shielding pattern using a light-shielding ink containing a mixed material of Al or 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, it is also possible to form a light-shielding pattern, which is a metal pattern, in the middle layer in a sequential layer structure, and a triple-layer structure in which diffusion patterns are formed in the upper and lower portions, 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.

The reflective film 120 is more preferably provided with a reflective pattern 121 through the white (whitr) printing to have a reflective material so as to disperse the light emitted from the light source and to promote the dispersion of light. In particular, the reflective film 120 is laminated on the printed circuit board, the LED light source 130 is protruded to the outside through the hole formed on the reflective film. When the LED light source is implemented as a side emission type structure, it is possible to greatly reduce the number of light sources as described above, and in order to reduce such a reduction rate, the reflective pattern 130 is provided to greatly improve the reflectance of the light. The reflective pattern may be printed using a reflective ink including any one of TiO ₂ , CaCO ₃ , BaSO ₄ , Al ₂ O ₃ , Silicon, and PS. The reflection pattern is preferably formed in the light exit direction of the LED light source, and in particular, the pattern may be arranged so that the pattern density increases as the distance from the LED light source exits.

4 illustrates an embodiment of forming an air gap module disposed between the optical pattern layer 150 and the diffusion plate 170 illustrated in FIGS. 2 and 3.

That is, in the configuration of the backlight unit according to the present invention, a structure including an air layer (second air region) 160 between the optical pattern layer 150 and the diffusion plate 170 may be added, and the second air region may be added. 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.

In this case, as described above, the embodiments of the air gap module may be combined with the embodiments of the optical pattern layer to be variously formed to have various structures. That is, the structure of the optical pattern 151 is printed below the one transparent substrate, or the optical pattern is disposed between the two substrates, and as shown here in the structure having an air layer around the pattern as described later The structure including the air gap module of the diffusion plate can be combined.

Specifically, the second air region 160, which may be formed between the optical pattern layer 150 and the diffusion plate 170, may have a structure in which an air layer may be formed below the diffusion plate. It can be formed by implementing, it is defined as an "air gap module" including the second air region implemented through this structure.

The air gap module includes both a method of forming an air region (air layer) by processing the diffusion plate itself or a structure of forming an air region by forming a separate structure below the diffusion plate.

That is, as shown in (a) of FIG. 4, the spacer 171 is formed under the diffusion plate 170 to implement the second air region 160, or as shown in (b), the lower portion of the diffusion plate. It may be implemented by the structure of the bridge 172 to form a second air area (160) in close contact with the lower layer by patterning. It is obvious that such an integral structure can be variously modified according to the patterned shape, that is, the shape of the pattern forming the air region, and accordingly, the shape of the bridge can be variously modified. Will be included. Furthermore, as in the structure shown in (c), the structure of forming the air region 160 using a separate structure other than the method of patterning the bottom surface of the diffusion plate can be also realized.

Although the illustrated structure illustrates a structure for forming the bridge 174 with a spacer member, the gist of the present invention is that various modified embodiments capable of implementing an air layer at the bottom of the diffuser plate, including this method, It will correspond to the point. (b) for patterning the diffusing plate itself or a structure (c) using a separate structure, as in the drawing shown in Fig. 4 (d) It is also possible to form the air regions 160 and 161 in a plurality of layers by employing the structures 175 and 176. [

The backlight unit according to the present invention as described above can implement the arrangement of the light source 130 that emits the excessive light (L) as shown in FIG. That is, the LED light source 130 may be disposed by applying a side emission LED to reduce the number of light sources.

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. The light may be prevented from being concentrated through the layer 150, and the deviation of light may be minimized through the second air region formed under the diffuser plate.

Specifically, the light emitted by the reflecting film 120 and the reflecting pattern 121 is higher the reflection efficiency, it is possible to guide the light 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 refined to increase the uniformity, it is incident to the LCD panel as white light through the optical sheet, such as prism sheet 180, DBEF 190, which is added later.

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, it is possible to improve the optical characteristics by controlling the problem of the luminance decrease and uniformity due to the reduction of the light source with the air pattern of the reflective pattern, the light shielding pattern and the air gap module.

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
130: Light source
140: Resin layer
150: optical pattern layer
151: optical pattern
152: first air zone
153:
160: second air area
170: diffusion plate
180: prism sheet
190: DBEF

Claims (20)

A plurality of side view LED light sources formed in a direct type on a printed circuit board and emitting light in a lateral direction;
A resin layer stacked in a structure surrounding the plurality of side light emitting LED light sources, for diffusing and reflecting the emitted light to guide the light forward; And
An optical pattern layer disposed on the resin layer and having a first air region surrounding a periphery of the optical pattern;
Including,
The optical pattern,
The backlight unit is implemented by using a light shielding ink, and controls a light shielding degree or diffusivity of light incident through the resin layer.
The method according to claim 1,
The optical pattern layer,
A first substrate and a second substrate including the optical pattern therein; And
An adhesive layer surrounding the first air region and adhering between the first substrate and the second substrate
The backlight unit is configured to include.
The method according to claim 2,
And a diffuser plate stacked on top of the optical pattern layer.
The method according to claim 3,
And an air gap module having a second air region between the optical pattern layer and the diffusion plate.
The method of claim 4,
The air gap module,
And a thickness of 0.01 to 2 mm, which is a thickness between the first substrate and the diffusion plate included in the optical pattern layer.
The method of claim 4,
The air gap module,
The backlight unit is formed of an integrated structure in which a lower portion of the diffusion plate is patterned to implement a second air region and a bridge.
The method of claim 4,
The air gap module,
The backlight unit is formed in a structure having a second air region by forming a bridge with an independent spacer member on the lower portion of the diffusion plate.
The method of claim 4,
The adhesive layer
A backlight unit formed of any one of thermosetting PSA, thermosetting adhesive, or UV curing PSA type.
A plurality of side light emitting type LED light sources formed in a direct type on a printed circuit board and emitting light in a lateral direction;
A resin layer stacked in a structure surrounding the plurality of side light emitting LED light sources, for diffusing and reflecting the emitted light to guide the light forward;
An optical pattern layer disposed on the resin layer, the optical pattern layer having an optical pattern in which a pattern density is adjusted in association with a direction in which light is emitted from the side-emitting LED light source;
A diffusion plate stacked on the optical pattern layer; And
An air gap module having a second air region between the optical pattern layer and the diffusion plate
Backlight unit comprising a.
The method according to claim 9,
The optical pattern layer,
The optical pattern is formed on the lower portion of the transparent substrate,
And a first air area surrounding a periphery of the optical pattern.
The method of claim 10,
The optical pattern layer,
A first substrate and a second substrate including the optical pattern therein; And
An adhesive layer surrounding the first air region and adhering between the first substrate and the second substrate
The backlight unit is configured to include.
The method according to claim 9,
The air gap module,
And a thickness of 0.01 to 2 mm, which is a thickness between the first substrate and the diffusion plate included in the optical pattern layer.
The method according to claim 9,
The air gap module,
The backlight unit is formed of an integrated structure in which a lower portion of the diffusion plate is patterned to implement a second air region and a bridge.
The method according to claim 9,
The air gap module,
The backlight unit is formed in a structure having a second air region by forming a bridge with an independent spacer member on the lower portion of the diffusion plate.
The method according to any one of claims 1 to 14,
The backlight unit includes:
And a reflective film having a reflective pattern stacked on an upper surface of the printed circuit board.
The method according to claim 15,
The reflective pattern is a backlight unit formed by applying a reflective ink containing any one of TiO ₂ , CaCO ₃ , BaSO ₄ , Al ₂ O ₃ , Silicon, PS.
The method according to claim 15,
Including a bead of 0.01 ~ 0.3% in the resin layer,
The bead increases reflection of the light.
The method according to claim 15,
The optical pattern,
A backlight unit which is a light shielding pattern formed of a material containing at least one material selected from TiO ₂ , CaCO ₃ , BaSO ₄ , Al ₂ O ₃ , Silicon, and PS.
The method according to any one of claims 3 to 14,
The backlight unit includes:
A reflective film having a reflective pattern stacked on an upper surface of the printed circuit board; And
And a prism sheet or a protective sheet stacked on the diffusion plate.
A liquid crystal display device comprising the backlight unit of claim 1.

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