KR20190073726A - Backlight unit and liquid crystal display device comprising the same - Google Patents

Abstract

According to the present invention, a backlight unit includes: a light source module; a reflecting plate; a support side; and a diffusion plate. The light source module has a light source, and a lens part for changing a direction of light provided from the light source, and extends in one direction. The reflecting plate is disposed on the lower side of the light source module, and has a cross-sectional shape which is inclined to have a predetermined incline or is bent to have a predetermined curvature in a lateral direction intersecting the one direction from the center part where the light source module is disposed in at least one region. The support side is disposed corresponding to at least one among one end or the other end of the light source module, extends in the lateral direction from the center part, and reflects incident light. The diffusion plate is disposed on the light source module and the support side. Therefore, the present invention is to provide a liquid crystal display device being lightweight and slim.

Description

BACKLIGHT UNIT AND LIQUID CRYSTAL DISPLAY DEVICE COMPRISING THE SAME [0002]

The present invention relates to a backlight unit and a liquid crystal display including the same.

The liquid crystal display device is used as a portable computer such as a notebook PC, an office automation device, an audio / video device, and an indoor / outdoor advertisement display device. A liquid crystal display controls an electric field applied to a liquid crystal layer of a liquid crystal display panel to display an image by modulating light incident from a backlight unit (BLU).

Conventional backlight units can be classified into a direct type and an edge type. The edge type backlight unit has a structure in which a light source is disposed so as to face the side face of the light guide plate and a plurality of optical sheets are disposed between the liquid crystal display panel and the light guide plate. In the edge type backlight unit, the light source irradiates light to one side of the light guide plate, and the light guide plate converts the linear light source or point light source into a planar light source, and irradiates the liquid crystal display panel. In the case of the edge type backlight unit, since the light source is disposed on the side surface of the light guide plate, the entire thickness can be reduced, and thus a liquid crystal display device having a slim (or thin) structure can be realized. However, in the case of the edge type backlight unit, since a relatively large number of light sources are required, the light characteristics may be deteriorated due to the heat emitted from the light source, and there is a problem in that the cost competitiveness, such as the necessity of a large number of light sources, .

The direct-type backlight unit has a structure in which a plurality of light sources are disposed under the liquid crystal display panel, and irradiates the light diffused through the diffusion plate to the liquid crystal display panel. In the case of the direct-type backlight unit, there is an advantage that it is advantageous in terms of cost competitiveness compared to the pseudo-type. However, in the case of the direct-type backlight unit, since the light sources are disposed under the diffusion plate, there is a problem that it is difficult to realize a slimmed liquid crystal display device. That is, the backlight unit needs to be spaced a certain distance between the diffusion plate and the light sources in consideration of the optical gap. In the direct type, since the light sources are disposed under the diffusion plate, There is nothing. In order to realize the slimming down of the backlight unit, it is possible to consider a method of reducing the optical gap. In this case, however, a dark portion, in which light can not reach due to the limit of the directivity angle (or the radiation angle) of the light source, Can be remarkably lowered.

In order to solve the above-described problems, it is necessary to provide a new type of backlight unit, which is not a backlight unit which is conventionally embodied as an edge type or direct type.

The present invention is to provide a lightweight and slimmed liquid crystal display device.

A backlight unit according to the present invention includes a light source module, a reflection plate, a support side, and a diffusion plate. The light source module has a light source and a lens portion for switching the direction of light provided from the light source, and extends in one direction. The reflector is disposed below the light source module and has a cross-sectional shape that is bent or has a predetermined inclination so as to have a predetermined curvature toward a side direction crossing one direction from a central portion where the light source module is disposed in at least one area. The support side is arranged corresponding to one of the ends of the light source module and extends in the lateral direction from the central portion, and reflects the incident light. The diffuser plate is disposed on the light source module and the support side.

The present invention has the advantage of being able to provide a backlight unit that is lightweight and slim and a liquid crystal display device including the backlight unit. The present invention can provide a backlight unit with remarkably improved luminance uniformity and a liquid crystal display device including the same.

1 is an exploded perspective view schematically showing a liquid crystal display device according to the present invention.
Fig. 2 is a cross-sectional view taken along line II 'of Fig. 1;
3 is a perspective view schematically showing a light source module and a peripheral structure thereof.
4 is a view schematically showing the traveling direction of light emitted from the light source module.
5 is a cross-sectional view schematically showing a path of light passing through a lens shape and a lens according to the present invention.
6 and 7 are views for explaining a floating bar according to the present invention.
8 and 9 are views for explaining the effect of the floating bar.
10 and 11 are views for explaining the optical path of the light emitted from the light source module.
12 and 13 are views for explaining a support side according to the first embodiment of the present invention.
Figs. 14 and 15 are views for explaining an example of the shape of the support side. Fig.
Fig. 16 is a view cut along the line A-A ', B-B' and C-C 'in Fig.
FIG. 17 is a diagram showing the luminance measurement results of the structures shown in FIGS. 10 and 11 and the structures shown in FIGS.
18 is a view showing an example of a fastening structure of a support side.
19 is a view showing another example of the fastening structure of the support side.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Like reference numerals throughout the specification denote substantially identical components. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description, a detailed description of known technologies or configurations related to the present invention will be omitted when it is determined that the gist of the present invention may be unnecessarily obscured. In describing the various embodiments, the same components are represented at the outset and may be omitted in other embodiments.

Terms including ordinals, such as first, second, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another.

1 is an exploded perspective view schematically showing a liquid crystal display device according to the present invention. Fig. 2 is a cross-sectional view taken along line I-I of Fig. 1. Fig. 3 is a perspective view schematically showing a light source module and a peripheral structure thereof. 4 is a view schematically showing the traveling direction of light emitted from the light source module.

1 to 3, a liquid crystal display device according to the present invention includes a liquid crystal display panel (PNL), a backlight unit disposed on the back surface of a liquid crystal display panel (PNL) and irradiating light to a liquid crystal display panel (PNL) do. The liquid crystal display panel (PNL) includes a thin film transistor substrate, a counter substrate, and a liquid crystal layer interposed between the thin film transistor substrate and the counter substrate. On the thin film transistor substrate of the liquid crystal display panel (PNL), an upper polarizer film and a lower polarizer film may be disposed on the opposite substrate, respectively. The upper polarizing film and the lower polarizing film transmit only components in a specific direction among components of the light irradiated from the backlight unit.

The thin film transistor substrate includes a thin film transistor array having a plurality of pixels. The pixels may be defined by a plurality of gate lines (not shown) and a plurality of data lines (not shown) intersecting each other, but are not limited thereto. Each pixel includes a thin film transistor (not shown) connected to a gate line and a data line, a pixel electrode (not shown) connected to the thin film transistor, and a common electrode (not shown) . At this time, the common electrode may be disposed on the counter substrate according to the driving method of the liquid crystal layer. And a pad portion connected to the panel driving portion is provided on one side of the thin film transistor substrate.

The counter substrate may be a color filter array substrate. However, if the liquid crystal display panel PNL is implemented by a COT (color filter on TFT) or a TOC (TFT on color filter) method, the color filter may be formed on the thin film transistor substrate. The counter substrate may be formed to have a relatively smaller area than the thin film transistor substrate, but the present invention is not limited thereto. The counter substrate may be disposed opposite to the thin film transistor substrate so as to overlap the remaining region except the pad portion of the thin film transistor substrate.

In one example, the opposing substrate may be located on the top surface of the thin film transistor substrate, and in another example, the thin film transistor substrate may be inverted to be located on the opposing substrate. The detailed configuration of the thin film transistor substrate and the counter substrate may be configured in various forms corresponding to the driving mode of the liquid crystal layer.

The liquid crystal layer is driven by an electric field generated by a potential difference between a data voltage supplied to the pixel electrode through the data lines and a common voltage supplied to the common electrode, thereby adjusting the amount of light transmitted through the liquid crystal display panel (PNL). The liquid crystal layer may be implemented in at least one of various liquid crystal modes. For example, the liquid crystal layer may be implemented in a TN (Twisted Nematic) mode, VA (Vertical Alignment) mode, IPS (In plane switching) mode, and FFS (Fringe field switching) mode.

The panel driving unit is connected to a pad unit provided on the thin film transistor substrate and transmits a signal for driving each pixel of the liquid crystal display panel (PNL). The panel driving unit may include at least one circuit film bonded to the pad portion of the liquid crystal display panel (PNL), and a printed circuit board connected to the circuit film. The circuit film may be implemented by a chip on film method in which a driving IC (Integrated Circuit) is mounted on a flexible film, but is not limited thereto. One end of the circuit film may be connected to the thin film transistor substrate, and the other end may be connected to the printed circuit board. One end of the circuit film may be bonded to the thin film transistor substrate through an anisotropic conductive film.

The backlight unit is provided on the back surface of the liquid crystal display panel (PNL) and emits light toward the liquid crystal display panel (PNL). The backlight unit includes a light source module (LM), a diffuser plate (DP), and a reflector plate (REF).

The light source module LM includes a light source LS, a light source printed circuit board LP, and a lens unit. The light source module LM is disposed at the center of the backlight unit. The light source module LM may be implemented as an array of bars extending in one direction.

The light source LS can be realized as a light emitting diode (LED) having advantages of high efficiency, high brightness, and low power consumption. The position and the arrangement density of the light sources LS can be appropriately selected in consideration of the optical characteristics in the central portion of the backlight unit.

The light source LS is turned on and off by receiving an electrical signal from the light source driving unit through the light source printed circuit board LP. A circuit for electrically connecting the light source LS and the light source driving unit is formed on the light source printed circuit board LP. The light source printed circuit board LP may be elongated in one direction. The light source LS may be disposed on the light source printed circuit board LP.

The lens unit is disposed on the light source LS and functions to emit light provided from the light source LS in a predetermined direction. That is, the lens portion is provided so as to have a predetermined shape, and can function to switch the traveling direction of the light provided from the light source LS and uniformly diffuse in a predetermined direction.

Specifically, the lens portion includes a bar-shaped lens LN extending in the one direction. The lens unit may include one lens LN extended in one direction. Alternatively, the lens portion may include a plurality of lenses LN that are divided into a plurality of lenses, and they may be arranged in parallel in one direction. When the lens portion includes a plurality of lenses LN, the advantage of easy machining and the ease of tightening / separating operation are advantageous for rework and the like.

Light provided from the light source LS can be redirected in a predetermined direction by the lens LN. That is, the lens LN controls the optical path so that the light provided from the light source LS is not concentrated at a specific position but is uniformly diffused from the central portion of the backlight unit provided with the light source module LM to the side portion.

Light emitted from the light source module LM can be directly incident on the diffuser plate DP and reflected by the reflector plate REF and incident on the diffuser plate DP. Light supplied from the light source module LM to the diffusion plate DP is diffused toward the liquid crystal display panel PNL. The backlight unit may further include an optical sheet unit OPS located on the diffuser plate DP so that the light passing through the diffuser plate DP passes through the optical sheet unit OPS, It can be uniformly irradiated to the back surface. The optical sheet portion OPS may include at least one diffusion sheet and a light collecting sheet, and may include various functional sheets such as a dual brightness enhancement film (DBEF).

The reflection plate REF functions to reflect the light provided from the light source module LM toward the diffusion plate DP. The reflection plate REF may have a predetermined shape in order to control the outgoing angle of light reflected by the reflection plate REF, in other words, in order to switch the direction of the incident light in a predetermined direction.

For example, the cross section of the reflection plate REF may have a shape curved at a predetermined curvature toward the side portion from the central portion provided with the light source module LM in at least one region. In at least one region, the distance between the reflection plate REF and the diffusion plate DP gradually decreases toward the side portion. In at least one region, the distance between the reflection plate REF and the diffusion plate DP gradually decreases toward the side portion.

In other words, the cross section of the reflector REF is curved at a predetermined curvature in the center portion provided with the light source module extending in one direction, and in the lateral direction extending in the direction intersecting (or perpendicular to) the one direction Shape.

The curvature can be set differently depending on the position. The sectional shape of the reflection plate REF may be symmetrical with respect to a virtual center line CL across the center. In at least one region, the distance between the reflection plate (REF) and the diffusion plate (DP) gradually decreases in the lateral direction.

As another example, the cross section of the reflection plate REF may have a shape inclined at a predetermined angle from the horizontal plane in at least one region. In at least one region, the distance between the reflection plate REF and the diffusion plate DP is gradually reduced toward the side portion (or the lateral direction).

The angle may be set differently depending on the position. The sectional shape of the reflection plate REF may be symmetrical with respect to a virtual center line CL across the center.

The reflection plate REF may be divided and provided in plural. For example, the reflection plate REF may be divided into two, and may be disposed on both side portions with respect to a central portion where the light source modules LM are disposed.

An air gap is provided between the reflection plate REF and the diffusion plate DP. The air gap can serve as a buffer for widely diffusing the light emitted from the light source module (LM).

The liquid crystal display panel (PNL) and the backlight unit are assembled together by a case member and are implemented as a liquid crystal module (LCM). The case member includes a guide panel GP and a cover bottom CB. The guide panel GP and the cover bottom CB are engaged with each other to accommodate the backlight unit inside.

The guide panel GP is interposed between the liquid crystal display panel PNL and the backlight unit so that the edge of the liquid crystal display panel PNL can be supported from the back face and the interval between the liquid crystal display panel PNL and the backlight unit It can be kept constant. The guide panel GP may have the shape of a rectangular frame having a through hole. The guide panel GP may be made of a plastic material such as polycabonate, but is not limited thereto.

The cover bottom CB can support the reflection plate REF at the back surface so that the reflection plate REF can maintain a predetermined shape. The cover bottom CB may be provided to have a shape corresponding to the reflection plate REF. For example, when the end face of the reflection plate REF has a predetermined curvature shape, the end face of the cover bottom CB may have a curved shape corresponding to a preset curvature, The cross section of the cover bottom CB may have a shape corresponding to the inclined shape by a predetermined angle from the horizontal plane.

The cover bottom CB can be made of a material having a high thermal conductivity and high rigidity so as to smoothly discharge heat from the panel driver and / or the light source module LM to the outside. As an example, the cover bottom CB may be made of aluminum, aluminum nitride (AlN), electrogalvanized steel sheet (EGI), stainless steel (SUS), galvalume (SGLC), aluminum plated steel (aka ALCOSTA), tinned steel And the like. Further, such a metal plate may be coated with a high conductivity material for promoting heat transfer.

The backlight unit may further include a support member (not shown) for preventing deflection of the diffusion plate DP. The support member can function to prevent the diffusion plate (DP) from being sagged by the load and / or heat, and to keep the diffusion plate (DP) and the reflection plate (REF) spaced apart at predetermined intervals.

The height of the support member may vary depending on the position. That is, since the reflector REF according to the present invention does not have a shape parallel to the horizontal plane, unlike the conventional reflector, the distance between the diffuser plate DP and the reflector REF may be different depending on the position. Correspondingly, the height of the support member that maintains the gap between the diffusion plate DP and the reflection plate REF may differ depending on the position.

The support member may be fastened to a support such as the cover bottom CB and fixed at a predetermined position. The support member may be formed of a plastic material such as polycabonate, but is not limited thereto.

Referring to FIG. 4, the light source module LM is provided at the center of the backlight unit. The light emitted from the light source LS of the light source module LM is widely dispersed on the entire surface of the backlight unit by the lens LN of the lens portion. A part of the light emitted from the light source module LM may be directly incident on the diffuser plate DP and the other part may proceed toward the reflector REF and then reflected by the reflector REF, Can be entered. The progress direction of the light emitted from the light source module LM and the degree of distribution of the light amount can be controlled by the lens LN provided in the lens portion.

The light from the light source LS is dispersed through the lens LN of the lens unit without proceeding directly to the diffusion plate DP like the conventional direct type backlight unit, do. Therefore, it is necessary to secure a wide optical gap as in the prior art in order to secure luminance uniformity. Therefore, the present invention has an advantage that a slimmed backlight unit and a liquid crystal display device including the backlight unit can be provided.

5 is a cross-sectional view schematically showing a path of light passing through a lens shape and a lens according to the present invention.

Referring to Fig. 5, the lens LN includes an upper surface P1, a side surface P2, and a lower surface P3. The lens LN may have a cross-sectional shape symmetrical with respect to an imaginary center line CL crossing the center in the up and down direction. The light source LS disposed at the lower portion of the lens LN may be disposed corresponding to the center line CL. Accordingly, the light emitted from the light source LS can be divided in different directions and uniformly emitted toward the both side surfaces P2.

Most of the light provided from the light source LS is reflected by the upper surface Pl of the lens LN and travels toward the side of the backlight unit. The upper surface P1 of the lens LN can function to induce the total reflection of the light provided from the light source LS and to suppress the vertical output light. The perpendicularly emitted light means light which is not reflected by the upper surface Pl of the lens LN among the light provided from the light source LS but transmitted or refracted and proceeds straight toward the diffusion plate DP. The upper surface P1 of the lens LN is provided so as to have a predetermined curvature, so that the total reflection direction and the light diffusion distribution can be controlled.

The side surface P2 of the lens LN can function to transmit most of the light reflected by the upper surface P1 of the lens LN and totally reflect a part of the light. The light reflected by the side surface P2 of the lens LN travels toward the upper portion UA of the lens LN or is reflected by the lower surface P3 of the lens LN, ). ≪ / RTI > In other words, the present invention can control the amount of light traveling to the upper portion UA of the lens LN by controlling the shape of the side surface P2 of the lens LN, The mura phenomenon that can occur can be improved. Accordingly, the present invention has an advantage of being able to provide a backlight unit with improved luminance uniformity and a liquid crystal display including the same.

The shape of the side surface P2 of the lens LN can be selected in consideration of the emission angle of the required light. For example, in the case where the lens portion includes a plurality of lenses LN, the shape of the side P2 of one lens LN and the other lens LN may be different, Can be selected in consideration of the emission angle of light. The emission angle can be selected in consideration of the directing direction of light finally emitted from the lens LN.

The lower surface P3 of the lens LN can function to transmit a part of the light reflected by the side surface P2 of the lens LN and to reflect the other part to the upper surface UA of the lens LN. The present invention can control the amount of light traveling to the upper portion UA of the lens LN using the light reflected by the side surface P2 and the lower surface P3 of the lens LN, ) Can be improved. Most of the light provided from the lens LN is incident on the reflection plate REF disposed on the cover bottom CB. The lower surface P3 of the lens LN is reflected by the reflection plate REF, The optical path of the re-incident light can be controlled. The lower surface P3 of the lens LN may be provided such that its cross section has a predetermined curvature in order to perform the above-described function.

A recess (RC) may be further provided on the lower surface P3 of the lens LN. The recess RC may be provided in a shape partially recessed inward from the lower surface P3 of the lens LN. The cross-sectional shape of the recess (RC) can be realized in the form of "? &Quot; with curvature. The shape of the recess RC can be selected in consideration of the curvature of the upper surface P1 of the lens LN for guiding total reflection of light. By providing the recess RC, the amount of light incident from the light source LS to the lens LN can be increased.

The recesses RC may extend in one direction along the shape of the lens LN and the light sources LS may be arranged in parallel along one direction corresponding to the position of the recesses RC. Although not shown, the light source LS can be accommodated in the recess RC, if necessary.

By including the lens portion having the above-described shape, the present invention has an advantage that light can be uniformly distributed over the entire diffusion plate DP with a small number of light sources LS provided in the central portion of the backlight unit.

The backlight unit according to the present invention may further include a floating bar (FB). The floating bar FB can perform a function of separating the light source module LM by a predetermined height from the cover bottom CB and aligning the light source module LM and the reflection plate REF to a predetermined position .

6 and 7 are views for explaining a floating bar according to the present invention. 8 and 9 are views for explaining the effect of the floating bar.

Referring to FIG. 6, the floating bar FB includes a base portion BP and a floating portion FP protruding from the base portion BP. The floating bar FB is made of a metal such as aluminum, aluminum nitride (AlN), electrogalvanized steel sheet (EGI), stainless steel (SUS), galvalume (SGLC), aluminum plated steel sheet (aka ALCOSTA), tinned steel sheet Materials.

The base portion BP can be fastened to the cover bottom CB. For example, the base portion BP can be fixed to the cover bottom CB by an adhesive member such as a thermal tape, and fixed to the cover bottom CB by a fixing member such as a screw . The base portion BP can be received in a forming portion FOA provided in the cover bottom CB.

It is preferable that the base portion BP has a large area and has a sufficient contact area with the cover bottom CB. Accordingly, the preferred embodiment of the present invention not only stably fixes the base portion BP to the cover bottom CB, but also sufficiently secures the heat radiation path of the heat generated from the light source module LM.

The floating portion FP is provided to have a predetermined thickness and is protruded from the cover bottom CB. The polarizing portion FP may be provided at a central portion of the base portion BP so as to have a smaller area than the base portion BP. The upper surface of the floating portion FP includes the seating surface SP and the inclined surface CP.

The seating surface SP is provided for sufficiently securing a path of light emitted from the light source module LM to the reflection plate REF and for this purpose the light source module LM In particular, the lens portion). On the seating surface SP, the light source module LM is seated. For example, as illustrated, a light source printed circuit board LP may be disposed on the seating surface SP, and a light source LS and a lens LN may be disposed on the light source printed circuit board LP.

The inclined plane CP is provided to direct some of the light emitted from the light source module LM to a target area and controls the inclination of the reflector REF located on the inclined plane CP 6 (b)). One end of the inclined surface CP is connected to the seating surface SP and the other end is connected to the upper surface of the base portion BP. The inclined plane CP is inclined by a predetermined angle with respect to the seating surface SP. A part of the reflection plate REF is seated on the inclined plane CP. That is, a part of the reflection plate REF is seated on the inclined plane CP in a state of being inclined at a predetermined angle corresponding to the inclination of the inclined plane CP.

More specifically, referring to FIG. 7A, the width W1 of the seating surface SP is set narrower than the width W2 of the lens LN of the lens portion. This means that the lens LN is provided so as to cover at least a part of the seating surface SP and the inclined surface CP. The light traveling toward the floating bar FB out of the light path-switched light by the lens LN can travel toward the inclined plane CP and this light travels toward the reflecting plate REF to be directed to the target area.

7B, the width W1 of the seating surface SP is equal to the width W3 of the light source printed circuit board LP or the width W3 of the light source printed circuit board LP, It may be desirable to provide a narrower width. That is, when the width W1 of the seating surface SP is larger than the width W3 of the light source printed circuit board LP and a part of the seating surface SP is exposed, the reflectance of the seating surface SP And the reflectance of the reflector (REF) substrate, the corresponding region can be recognized by the user as a dark portion, which may cause a deterioration of the display quality. Therefore, it may be desirable to completely shield the seating surface SP using a light source printed circuit board (LP). The area can be recognized by the user as a dark part, which can be a factor for lowering the display quality. Therefore, it may be desirable to completely shield the seating surface SP using a light source printed circuit board (LP).

8A shows the distribution of light output in the structure in which the floating bar FB is absent and FIG. 8B shows the outgoing light in the structure in which the floating bar FB is provided but does not include the inclined plane CP Respectively.

Referring to FIG. 8, the distribution of light emitted from the light source module LM can be divided into a first area A1 and a second area A2. The first area A1 is a region where light emitted from the light source module LM is directly distributed to the diffusion plate DP and the second area A2 is emitted from the light source module LM, And is a region where light traveling to the diffuser plate DP is distributed. A third region where light is relatively less distributed between the first region A1 and the second region A2 when the floating bar FB does not exist or when the floating bar FB does not include the inclined plane CP A3) exists. In this case, the third area A3 can be visually recognized by the user as the dark part, which may cause the display quality to significantly deteriorate.

Fig. 8 (c) shows the luminance profile in the structure shown in Fig. 8 (a). Referring to FIG. 8 (c), it can be seen that a luminance inflection point has occurred in the left / right side (corresponding to the third area A3) with respect to the central part where the light source module LM is disposed. The region in which the luminance inflection point is generated is problematic because it can be recognized as a dark portion by the user.

9 (a) shows an emission distribution in a preferred embodiment of the present invention with a floating bar FB having an inclined plane CP, and Fig. 9 (b) shows the distribution of light in the preferred embodiment of the present invention Brightness profile.

Referring to FIG. 9A, in a preferred embodiment of the present invention, a light source module LM is provided with a floating bar FB having a sloped surface CP, It can be seen that the luminance uniformity can be improved. Referring to FIG. 9 (b), since the luminance inflection point of FIG. 8 (c) disappears, it can be seen that the visibility of the dark portion can be improved in the preferred embodiment of the present invention.

Hereinafter, a novel structure is proposed, in which light provided from the light source module LM can travel to the end of the side portion and luminance uniformity can be ensured.

≪ Embodiment 1 >

10 and 11 are views for explaining the optical path of the light emitted from the light source module. 12 and 13 are views for explaining a support side according to the first embodiment of the present invention.

10 and 11, the planar shape of the backlight unit may have a substantially rectangular shape. Correspondingly, the planar shape of the cover bottom CB can have a substantially rectangular shape as shown in the figure. The cover bottom CB includes a horizontal portion HP surrounding the lower portion of the backlight unit and a vertical portion VP extending from the horizontal portion HP and surrounding the side SIP of the cover bottom CB.

The cover bottom CB is connected to one side of the first short side S1, the second short side S2 opposite to the first short side S1, one side of the first short side S1 and the second short side S2 A first long side S3 and a second long side S4 connected to the other side of the first short side S1 and the other side of the second short side S2 and opposed to the first long side S3. Hereinafter, for convenience of explanation, the area corresponding to the first short side S1 is defined as the first side area A1, and the area corresponding to the second short side S2 is defined as the second side area A2 The area corresponding to the first long side S3 is defined as the third side area A3 and the area corresponding to the second long side S4 is defined as the fourth side area A4.

The light source module LM located at the center of the backlight unit extends in one direction, and the one direction corresponds to the extending direction of the first short side S1 and the second short side S2. The light emitted from the light source of the light source module LM is converted by the lens LN and emitted toward the first to fourth side areas A1, A2, A3, and A4.

The light traveling to the first side area A1 and the second side area A2 can be effectively and evenly dispersed by controlling the shape of the lens LN and the curvature (or slope) of the reflection plate REF, It is difficult to control the light traveling to the three side areas A3 and the fourth side area A4 to secure the light uniformity. That is, the light traveling to the third side area A3 and the fourth side area A4 is absorbed (or lost) by the vertical part VP of the cover bottom CB, You can. The light traveling to the third side area A3 and the fourth side area A4 is concentrated in the area AA adjacent to the light source module LM and does not reach the area BA spaced from the light source module LM As a result, the user may recognize that the spaced region BA is a dark portion.

The light traveling to the third side area A3 and the fourth side area A4 is diffusely reflected by the cover bottom CB and is recognized as a bright line defect or is recognized as yellowish light that is not white can do. This is problematic because the display characteristics are significantly lowered.

12 and 13, the backlight unit according to the first embodiment of the present invention includes a support side SS provided at at least one of the third side area A3 and the fourth side area A4, side. The support side SS is arranged corresponding to at least one of the one end and the other end of the light source module LM and one end of the support side SS is connected to the first side area A1 from the center part provided with the light source module LM And the other end of the support side SS extends from the central portion provided with the light source module LM toward the second lateral area A2. The cross-sectional shape of the support side SS may be symmetrical with respect to a virtual center line crossing the center.

The support side SS has a reflection characteristic and can reflect the incident light. The support side SS may include a reflective material, and the surface of the base layer may be coated with a reflective material or provided with a reflective sheet attached thereto. For example, the support side SS may be implemented in the form of silver (Ag) reflection processed on the surface of the base layer.

The support side SS includes a side face SIP opposing the light source module LM and an upper face UP connected to the side face SIP and opposed to the diffusion plate DP.

The side surface SIP of the support side SS functions to reflect the incident light toward the reflection plate REF and / or the diffusion plate DP. The present invention can improve the overall brightness of the backlight unit by reusing light that can be absorbed and absorbed by the cover bottom CB by using the side surface SIP of the support side SS, There is an advantage that the light uniformity can be improved by controlling the direction of the light.

The upper surface UP of the support side SS can provide a path of travel of light incident between the diffusion plate DP and the upper surface UP of the support side SS. That is, the upper surface UP of the support side SS supports the light incident between the diffusion plate DP and the upper surface UP of the support side SS to the first side area A1 and the second side area A2 , And can function as the path. The present invention uses the upper surface UP of the support side SS to irradiate light that can be concentrated in the area AA adjacent to the light source module LM to a relatively spaced area BA from the light source module LM It has an advantage that the light uniformity can be remarkably improved.

Figs. 14 and 15 are views for explaining an example of the shape of the support side. Fig. Fig. 16 is a view cut along the line A-A ', B-B' and C-C 'in Fig.

14, since the first embodiment of the present invention secures the flow path of the light through the upper surface UP of the support side SS, the upper surface UP of the support side SS, And the diffusing plate (DP). The angle? Between the upper surface UP of the support side SS and the side surface SIP needs to be appropriately controlled in order to secure a space between the upper surface UP of the support side SS and the diffusion plate DP have. When the angle? Formed by the upper surface UP of the support side SS and the side surface SIP is set to an acute angle, light to the space between the upper surface UP of the support side SS and the diffusion plate DP The inflow may not be easy. Therefore, it is preferable that the angle? Between the upper surface UP of the support side SS and the side surface SIP is set to a right angle or an obtuse angle.

The angle θ formed by the upper surface UP of the support side SS and the side surface SIP is set to be smaller than the angle formed by the upper surface UP of the support side SS and the side surface SIP in order to induce light inflow into the space between the upper surface UP of the support side SS and the diffusion plate DP A method may be considered in which the height of the upper surface UP of the support side SS is uniformly lowered without adjusting the height of the support side SS. However, in this case, the light advances through the support side SS to the cover bottom CB, Which is undesirable. Therefore, in a state in which the portion of the upper surface UP of the support side SS adjacent to the cover bottom CB is located at a height sufficient to cover the horizontal portion HP of the cover bottom CB, the support side SS The angle formed by the upper surface UP and the side surface SIP is preferably adjusted.

14 (a), 14 (b) and 14 (c) show a state in which the upper surface UP of the support side SS is moved in accordance with the angle θ formed by the upper surface UP of the support side SS and the side surface SIP, And the diffusion plate (DP). As shown, the larger the angle? Between the upper surface UP of the support side SS and the side surface SIP is, the larger the gap between the upper surface UP of the support side SS and the diffusion plate DP The amount of incident light can be increased.

15 and 16, the angle? Between the upper surface UP of the support side SS and the side surface SIP can be selected differently depending on the positions, in consideration of the light uniformity and the positional characteristics. have. That is, the angle? Between the upper surface UP of the support side SS and the side surface SIP is equal to an angle? Between any one area adjacent to the light source module LM and another area adjacent to the light source module LM, Lt; / RTI >

Since the light provided from the light source module LM is concentrated in the region adjacent to the light source module LM, the upper surface UP of the support side SS can be prevented from being reflected on the side surface SIP of the support side SS It is required to guide light in the direction of the first lateral area A1 and the second lateral area A2. That is, in the region adjacent to the light source module LM, the angle? Formed by the upper surface UP of the support side SS and the side surface SIP is controlled to be relatively large, and the upper surface UP of the support side SS, It is possible to mainly induce the light inflow into the diffusion plate DP.

Since the light amount directly provided from the light source module LM is relatively small in the region relatively distant from the light source module LM, the light is not guided to the upper surface UP of the support side SS, It is required to reflect the incident light to the reflection plate REF and / or the diffuser plate DP in order to prevent the light reflected by the reflection plate REF and / or the diffusing plate DP from being lost. That is, in the region relatively spaced from the light source module LM, the angle? Formed by the upper surface UP of the support side SS and the side surface SIP is controlled to be relatively small, RTI ID = 0.0 > SIP). ≪ / RTI >

The angle? Formed by the upper surface UP of the support side SS and the side surface SIP is larger than the angle? Between the upper surface UP of the support side SS and the side surface SIP of the light source module LM from the central portion of the light source module LM to the first lateral area A1 The lateral area A2), as shown in Fig. In other words, the distances D1, D2, and D3 from the boundary between the upper surface UP of the support side SS and the side surface SIP to the diffuser plate DP are smaller than the distance D1 from the central portion of the light source module LM to the first side Can be controlled to be progressively smaller toward the region A1 (or the second lateral region A2). Accordingly, the first embodiment of the present invention can provide a backlight unit with remarkably improved light uniformity and a liquid crystal display device including the same.

FIG. 17 is a diagram showing the luminance measurement results of the structures shown in FIGS. 10 and 11 and the structures shown in FIGS.

17A is a simulation result of measuring the luminance of the structure shown in FIGS. 10 and 11, and FIG. 17B is a simulation result of measuring the luminance of the structure shown in FIG. 12 and FIG. 17A and 17B, the structure according to the first embodiment of the present invention including the support side SS is different from the structure including no support side SS, It can be seen that the light is not concentrated on the peripheral portion but is dispersed to the peripheral portion. That is, in the case of including the support side SS, the light is sufficiently transmitted to the third side area A3 and the fourth side area A4 as well as the first side area A1 and the second side area A2. It can be seen that, by spreading, the luminance uniformity can be improved.

≪ Embodiment 2 >

18 is a view showing an example of a fastening structure of a support side. 19 is a view showing another example of the fastening structure of the support side.

The support side SS according to the second embodiment of the present invention can be fixed to the horizontal portion HP of the cover bottom CB at the inside of the cover bottom CB. The support side SS can be fixed to the cover bottom CB so that its movement can be restricted and restricted.

Referring to Fig. 18, as an example, the support side SS may include a protrusion PD. The projecting portion PD has a shape protruding outward from the side surface SIP of the support side SS. The projecting portion PD can be disposed opposite to the horizontal portion HP of the cover bottom CB. The projecting portion PD and the cover bottom CB can be mutually fixed via a fixing member such as a screw or a hook.

A long reflection plate REF may be interposed between the protrusion PD and the cover bottom CB so that the fixing member can fasten the protrusion, the reflection plate REF and the cover bottom CB at the same time. This has the advantage that a plurality of fixtures can be fastened at the same time by using one fixing member. However, when the fastening structure is not shielded and exposed to the optical path, the light may be irregularly reflected by the fastening structure in an undesired direction, or a defect may be recognized by the user.

19, in another example, the support side SS includes a back side LP connected to the side surface SIP and facing the horizontal portion HP of the cover bottom CB. The horizontal portions HP of the support side SS and the cover bottom CB can be mutually fixed via a fixing member such as a hook or a screw. In this case, since the fastening structure is shielded by the support side SS and is not exposed to the optical path, it is possible to prevent defects in which the light is irregularly reflected in an undesired direction or is perceived by the user. Accordingly, there is an advantage that a backlight unit in which display characteristics are remarkably improved and a liquid crystal display including the backlight unit can be provided.

The support side SS may further include a lead-in groove IG partially recessed inward from the support side SS side (SIP). In the lead-in groove IG, the reflector REF can be elongated and partially extended. The reflection plate REF can be fixed to the cover bottom CB as the support side SS presses the upper portion of the reflection plate REF at the time of fastening the support side SS and the cover bottom CB. This has the advantage that a plurality of fixtures can be fastened at the same time by using one fixing member.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

PNL: liquid crystal display panel LM: light source module
LS: Light source LP: Light source Printed circuit board
REF: Reflector FB: Floating bar
BP: Base portion FP: Floating portion
SP: seat surface CP: slope surface
DP: diffusion plate CB: cover bottom
HP: Horizontal VP: Vertical
SS: Support side UP: Top side of support side
SIP: Top surface of the support side

Claims (12)

A light source module having a light source and a lens unit for switching the direction of light provided from the light source, the light source module extending in one direction;
A reflector disposed under the light source module and having a sectional shape that is bent to have a predetermined curvature or has a predetermined inclination from a central portion in which the light source module is arranged in at least one region to a lateral direction crossing the one direction, ;
A support side disposed corresponding to one of the ends of the light source module and extending in the lateral direction from the center portion and reflecting the incident light; And
And a diffusion plate disposed on the light source module and the support side.
The method according to claim 1,
The support side includes:
A side opposite to the light source module; And
And a top surface connected to the side surface and tilted at a predetermined angle from the side surface to face the diffusion plate.
3. The method of claim 2,
The predetermined angle may be,
Said backlight unit being at said right angle or obtuse angle.
3. The method of claim 2,
The predetermined angle may be,
The first region being adjacent to the light source module and the second region being spaced apart from the light source module relative to the first region.
3. The method of claim 2,
The predetermined angle may be,
Wherein the backlight unit is gradually reduced in the lateral direction in at least one region.
3. The method of claim 2,
The distance from the boundary between the upper surface and the side surface of the support side to the diffusion plate,
Wherein the backlight unit is gradually reduced in the lateral direction in at least one region.
3. The method of claim 2,
And a cover bottom for supporting the reflection plate on the back surface of the reflection plate,
The support side includes:
And a protrusion projecting from a side surface of the support side and facing the cover bottom,
Wherein the protruding portion and the cover bottom,
And is fastened to each other by a fixing member.
3. The method of claim 2,
And a cover bottom for supporting the reflection plate on the back surface of the reflection plate,
The support side includes:
And a back surface that is connected to a side surface of the support side and faces the cover bottom,
The back side of the support side and the cover bottom,
And is fastened to each other by a fixing member.
9. The method of claim 8,
Side surface of the support side,
And a lead-in groove into which one end of the reflection plate is inserted.
A light source module having a light source and a lens unit for switching the direction of light provided from the light source, the light source module extending in one direction;
A reflector disposed under the light source module and having a sectional shape that is bent to have a predetermined curvature or has a predetermined inclination from a central portion in which the light source module is arranged in at least one region to a lateral direction crossing the one direction, ;
A support side disposed corresponding to one of the ends of the light source module and extending in the lateral direction from the center portion and reflecting the incident light;
A diffusion plate disposed on the light source module and the support side; And
And a liquid crystal display panel disposed on the diffusion plate.
11. The method of claim 10,
The lens unit includes:
At least one lens extending in one direction and provided in a bar shape,
The lens,
And reflects a part of the light provided from the light source toward the reflection plate and transmits the other part.
11. The method of claim 10,
The distance between the reflection plate and the diffuser plate may be,
And gradually decreases in the lateral direction in the at least one region.

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