KR20190073730A - 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 cover bottom; a diffusion plate; and a support member. The light source module extends in one direction. The reflecting plate is disposed on the lower side of the light source module, and extends in a lateral direction intersecting the one direction from the center part in which the light source module is disposed. The cover bottom is disposed on the lower side of the reflecting plate to support the reflecting plate. The diffusion plate is disposed on the light source module. The support member is disposed on the lower side of the diffusion plate to support the diffusion plate. The support member includes a base part and a support part. The base part is interposed between the reflecting plate and the cover bottom. The support part penetrates and extends through a first open hole provided in the reflecting plate from the base part, and supports the diffusion plate. Therefore, the present invention is to provide the 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 cover bottom, a diffusion plate, and a support member. The light source module extends in one direction. The reflector is disposed under the light source module and extends from a central portion in which the light source module is disposed, in a lateral direction intersecting the one direction. The cover bottom is disposed under the reflector to support the reflector. The diffusion plate is disposed on the light source module. The support member is disposed under the diffusion plate to support the diffusion plate. The support member includes a base portion and a support portion. The base is interposed between the reflector and the cover bottom. The support portion extends from the base portion through the first open hole provided in the reflection plate, and supports the diffusion plate.

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.

Further, the present invention can provide a backlight unit having a diffuser plate supporting member and preventing the diffusion plate from being sagged, while reducing deterioration of optical characteristics by the diffuser plate supporting member, and a liquid crystal display device including the backlight unit.

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 is a view for explaining a support member according to the first embodiment of the present invention.
11 and 12 are views for explaining a support member according to a second embodiment of the present invention.
13 is a view for explaining a support member according to a third embodiment of the present invention.
14 is a view for explaining a support member according to a fourth embodiment of the present invention.
Fig. 15 is a view for explaining the arrangement of support members according to the fifth embodiment of the present invention. Fig.

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.

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.

≪ Embodiment 1 >

10 is a view for explaining a support member according to the first embodiment of the present invention.

Referring to FIG. 10, the backlight unit according to the first embodiment of the present invention includes a support member DPS1 for preventing deflection of the diffusion plate DP. The support member DPS1 can prevent the diffusion plate DP from being sagged by the load and / or heat and maintain the state in which the diffusion plate DP and the reflection plate REF are spaced apart at predetermined intervals. The arrangement position and the placement density of the support member DPS1 can be appropriately selected in consideration of the area of the backlight unit and the rigidity of the support member DPS1.

The support member DPS1 includes a support portion B1, a base portion B2, and a fastening portion B3. The support portion B1, the base portion B2, and the fastening portion B3 may be provided as one body.

The support portion B1 is provided to have a predetermined height to support the diffusion plate DP from the backside. The upper portion of the support portion B1 may be arranged to directly contact the diffusion plate DP. The supporting portion B1 may be formed in a cylindrical shape having a constant cross-sectional area from the lower portion to the upper portion (Fig. 10 (a)). Alternatively, the support portion B1 may be formed in a conical shape in which the sectional area gradually decreases from the lower portion to the upper portion (FIG. 10 (b)). In order to prevent the optical path from being blocked by the support portion B1, it is preferable that the cross-sectional area of the support portion B1 is set relatively narrow.

The base B2 has a cross-sectional area wider than the cross-sectional area of the support B1. Unlike the support portion B1, the base portion B2 is preferably provided so as to have a relatively large area so as to secure a sufficient contact area with the base material. By securing a sufficient contact area of the base portion B2, the support member DPS1 can be more stably fixed to the cover bottom CB. The base B2 can be disposed on the reflection plate REF and the support B1 can extend from the upper surface of the base B2 toward the diffusion plate DP.

The fastening portion B3 extends from the back surface of the base portion B2 and functions to fasten the support member DPS1 to the cover bottom CB. The fastening portion B3 may extend through the open hole OH provided in the reflection plate REF and the cover bottom CB. The fastening portion B3 can be fitted to the reflection plate REF and the cover bottom CB.

The fastening portion B3 may include a hook HK provided at one end thereof. The hook HK is disposed to cover at least a part of the back surface of the cover bottom CB and can abut the back surface of the cover bottom CB. By the hook HK, the flow of the support member DPS1 fastened to the cover bottom CB is restricted.

The support member DPS1 may be formed of a plastic material such as polycabonate, but is not limited thereto. The support member DPS1 is made of a transparent material. Thereby, there is an advantage that the amount of light absorbed by the support member DPS1 due to the light provided toward the support member DPS1 can be minimized.

≪ Embodiment 2 >

As described in the first embodiment (see Fig. 10), in order to stably fix the support member DPS1, it is necessary that the base portion B2 has a sufficient area. However, when the base B2 is disposed on the reflection plate REF as in the first embodiment, since the base B2 having a large area is exposed to the outside of the reflection plate REF, B2, which may be perceived by the user as a dark spot. The second embodiment suggests a way to improve this.

11 and 12 are views for explaining a support member according to a second embodiment of the present invention.

Referring to Fig. 11, the backlight unit according to the second embodiment of the present invention includes a support member DPS2 for preventing deflection of the diffusion plate DP. The support member DPS2 can prevent the diffusion plate DP from being sagged by the load and / or heat, and can keep the diffusion plate DP and the reflection plate REF apart from each other at a predetermined interval. The arrangement position and the placement density of the support member DPS2 can be appropriately selected in consideration of the area of the backlight unit and the rigidity of the support member DPS2.

The support member DPS2 includes a support portion B1, a base portion B2, and a fastening portion B3. The support portion B1, the base portion B2, and the fastening portion B3 may be provided as one body.

The support portion B1 is provided to have a predetermined height to support the diffusion plate DP from the backside. The upper portion of the support portion B1 may be arranged to directly contact the diffusion plate DP. The support portion B1 may be provided in a cylindrical shape having a constant cross-sectional area from the lower portion to the upper portion, and may have a conical shape in which the cross-sectional area gradually decreases from the lower portion to the upper portion. In order to prevent the optical path from being blocked by the support portion B1, it is preferable that the cross-sectional area of the support portion B1 is set relatively narrow.

The base B2 has a cross-sectional area wider than the cross-sectional area of the support B1. Unlike the support portion B1, the base portion B2 is preferably provided so as to have a relatively large area so as to secure a sufficient contact area with the base material. By securing the sufficient contact area of the base portion B2, the support member DPS2 can be more stably fixed to the cover bottom CB.

The base B2 is interposed between the reflection plate REF and the cover bottom CB. The reflection plate REF is disposed so as to cover the base unit B2 and can reflect light that can be lost by the base unit B2 toward the diffusion plate REF. Accordingly, the second embodiment of the present invention has an advantage that the light efficiency can be remarkably improved. In addition, since the base B2 is shielded by the reflection plate REF, it is possible to minimize the defect in which the region where the base B2 is disposed is recognized as the dark portion. Accordingly, the second embodiment of the present invention can provide a backlight unit with remarkably improved display characteristics and a liquid crystal display device including the same.

The support part B1 extends from the upper surface of the base part B2 through the first open hole OH1 provided in the reflection plate REF. The support portion B1 extending through the first open hole OH1 extends toward the diffusion plate REF and supports the diffusion plate REF.

The fastening portion B3 extends from the back surface of the base portion B2 and functions to fasten the support member DPS2 to the cover bottom CB. The fastening portion B3 may extend through the second open hole OH2 provided in the cover bottom CB. The fastening portion B3 can be fitted to the cover bottom CB.

The fastening portion B3 may include a hook HK provided at one end thereof. The hook HK is disposed to cover at least a part of the back surface of the cover bottom CB and can abut the back surface of the cover bottom CB. By the hook HK, the flow of the support member DPS2 fastened to the cover bottom CB is restricted.

In the case of the support member DPS2 shown in Fig. 11, since the base portion B2 is disposed below the reflection plate REF, the reflection plate REF can not be fixed in place and can be detached. In this case, optical characteristics of the backlight unit may be changed, or damage may be caused by interference with other substrates, resulting in deterioration of display quality. The supporting portion B1 of the supporting member DPS2 needs to have a predetermined rigidity in order to support the diffusion plate DP and the like and it is necessary to secure a predetermined sectional area (or thickness). In this case, since the area of the first open hole OH1 through which the support portion B1 penetrates must be large, light is lost through the first open hole OH1, and the region can be visually recognized as an arm portion It is a problem.

Referring to Fig. 12, the support portion B1 includes a neck portion NP, and an extension portion EP. The neck portion NP is a portion extending from the base portion B2 and the extending portion EP is a portion extending from the neck portion NP.

The extension part EP can be provided in a cylindrical shape having a constant cross-sectional area from the lower part to the upper part (FIG. 12 (a)) and can be formed in a conical shape in which the cross-sectional area gradually decreases from the lower part to the upper part 12 (b)).

The lower portion of the extending portion EP is provided so as to have a larger cross-sectional area than the neck portion NP. Due to the difference in area, a step is provided between the extended portion EP and the neck portion NP, and the reflector REF is introduced into the stepped portion. At this time, the lower portion of the extended portion EP is provided to have a sectional area D2 that is wider than the hole area D1 of the first open hole OH1 provided in the reflection plate REF. The reflection plate REF is restricted in flow by the extending portion EP disposed on the upper surface and the base portion B2 arranged on the rear surface. Thus, there is an advantage that the reflection plate REF can be fixed in place and the problem of deterioration of display quality can be advantageously obtained.

Since the area of the first open hole OH1 can be reduced correspondingly by including the neck portion NP having a relatively narrow area as compared with the support portion B1, Can be minimized, and the occurrence of dark portions can be minimized. Further, since the area in which the reflection plate REF is disposed is relatively wider, the light efficiency can be improved correspondingly.

≪ Third Embodiment >

In the case of the second embodiment (see Fig. 12), the area of the first open hole OH1 can be minimized to improve the defect of the dark portion. However, since the first open hole OH1 is provided, It is inevitable. The third embodiment of the present invention proposes a way to improve this.

13 is a view for explaining a support member according to a third embodiment of the present invention.

Referring to FIG. 13, the backlight unit according to the third embodiment of the present invention includes a support member DPS3 for preventing deflection of the diffusion plate DP. The support member DPS3 can prevent the diffusion plate DP from being sagged by the load and / or heat and maintain the state in which the diffusion plate DP and the reflection plate REF are spaced apart by a predetermined interval. The arrangement position and the placement density of the support member DPS3 can be appropriately selected in consideration of the area of the backlight unit and the rigidity of the support member DPS3.

The support member DPS3 includes a support portion B1, a base portion B2, and a fastening portion B3. The support portion B1, the base portion B2, and the fastening portion B3 may be provided as one body.

The support portion B1 is provided to have a predetermined height to support the diffusion plate DP from the backside. The upper portion of the support portion B1 may be arranged to directly contact the diffusion plate DP. The support portion B1 may be provided in a cylindrical shape having a constant cross-sectional area from the lower portion to the upper portion, and may have a conical shape in which the cross-sectional area gradually decreases from the lower portion to the upper portion. In order to prevent the optical path from being blocked by the support portion B1, it is preferable that the cross-sectional area of the support portion B1 is set relatively narrow.

The base B2 has a cross-sectional area wider than the cross-sectional area of the support B1. Unlike the support portion B1, the base portion B2 is preferably provided so as to have a relatively large area so as to secure a sufficient contact area with the base material. By securing a sufficient contact area of the base portion B2, the support member DPS3 can be more stably fixed to the cover bottom CB.

The base B2 is interposed between the reflection plate REF and the cover bottom CB. The reflection plate REF is disposed so as to cover the base unit B2 and can reflect light that can be lost by the base unit B2 toward the diffusion plate REF.

The support part B1 extends from the upper surface of the base part B2 through the first open hole OH1 provided in the reflection plate REF. The support portion B1 extending through the first open hole OH1 extends toward the diffusion plate REF and supports the diffusion plate REF.

The support portion B1 includes a neck portion NP, and an extension portion EP. The neck portion NP is a portion extending from the base portion B2 and the extending portion EP is a portion extending from the neck portion NP.

The extension EP includes a first extension EP1 and a second extension EP2. The first extending portion EP1 is a portion extending from the neck portion NP and the second extending portion EP2 is a portion extending from the first extending portion EP1. The first extended portion EP1 may be formed in a conical shape in which the cross-sectional area gradually decreases from the lower portion to the upper portion. The second extended portion EP2 may be formed by a cylindrical phenomenon having a constant sectional area from the lower portion to the upper portion.

As described above, the extending portion EP according to the third embodiment of the present invention is provided with a double structure to secure a rigidity enough to prevent deflection of the diffusion plate DP, . That is, the first extended portion EP1 is provided to have a predetermined cross-sectional area to secure a predetermined rigidity, and the second extended portion EP2 is provided to have a relatively narrow cross-sectional area, thereby minimizing the optical path interruption.

The lower portion of the first extended portion EP1 extending from the neck portion NP has a shape in which the corner CN is rounded to a predetermined curvature. The second embodiment of the present invention can locally brighten the area by inducing the scattering of light provided by the rounded corners CN, The area can be minimized by compensating for the visibility of the dark spot.

The fastening portion B3 extends from the back surface of the base portion B2 and functions to fasten the support member DPS3 to the cover bottom CB. The fastening portion B3 may extend through the second open hole OH2 provided in the cover bottom CB. The fastening portion B3 can be fitted to the cover bottom CB.

The fastening portion B3 may include a hook HK provided at one end thereof. The hook HK is disposed to cover at least a part of the back surface of the cover bottom CB and can abut the back surface of the cover bottom CB. By the hook HK, the flow of the support member DPS3 fastened to the cover bottom CB is restricted.

In the above description, the extension part according to the third embodiment of the present invention is provided with a double structure. However, the present invention is not limited thereto, and the third embodiment of the present invention is characterized in that the extension part is a single- As shown in FIG.

<Fourth Embodiment>

In the first and second embodiments, since the open holes OH and OH1 are provided, a predetermined optical loss is inevitable. The fourth embodiment of the present invention proposes a method for improving this.

14 is a view for explaining a support member according to a fourth embodiment of the present invention.

Referring to Figure 14 (a), the backlight unit according to the fourth embodiment of the present invention includes a support member DPS4 for preventing deflection of the diffusion plate DP. The support member DPS4 can prevent the diffusion plate DP from being sagged due to the load and / or heat, so that the diffusion plate DP and the reflection plate REF can be kept apart from each other at predetermined intervals. The arrangement position and the placement density of the support member DPS4 can be appropriately selected in consideration of the area of the backlight unit and the rigidity of the support member DPS4.

The support member DPS4 includes a support B1, a base B2 and a fastening B3. The support portion B1, the base portion B2, and the fastening portion B3 may be provided as one body.

The support portion B1 is provided to have a predetermined height to support the diffusion plate DP from the backside. The upper portion of the support portion B1 may be arranged to directly contact the diffusion plate DP. The support portion B1 may be provided in a cylindrical shape having a constant cross-sectional area from the lower portion to the upper portion, and may have a conical shape in which the cross-sectional area gradually decreases from the lower portion to the upper portion. In order to prevent the optical path from being blocked by the support portion B1, it is preferable that the cross-sectional area of the support portion B1 is set relatively narrow.

The base B2 has a cross-sectional area wider than the cross-sectional area of the support B1. Unlike the support portion B1, the base portion B2 is preferably provided so as to have a relatively large area so as to secure a sufficient contact area with the base material. By securing sufficient contact area of the base portion B2, the support member DPS4 can be more stably fixed to the cover bottom CB.

The base B2 is interposed between the reflection plate REF and the cover bottom CB. The reflection plate REF is disposed so as to cover the base unit B2 and can reflect light that can be lost by the base unit B2 toward the diffusion plate REF.

The support part B1 extends from the upper surface of the base part B2 through the first open hole OH1 provided in the reflection plate REF. The support portion B1 extending through the first open hole OH1 extends toward the diffusion plate REF and supports the diffusion plate REF.

The fastening portion B3 extends from the back surface of the base portion B2 and functions to fasten the support member DPS4 to the cover bottom CB. The fastening portion B3 may extend through the second open hole OH2 provided in the cover bottom CB. The fastening portion B3 can be fitted to the cover bottom CB.

The fastening portion B3 may include a hook HK provided at one end thereof. The hook HK is disposed to cover at least a part of the back surface of the cover bottom CB and can abut the back surface of the cover bottom CB. By the hook HK, the flow of the support member DPS4 fastened to the cover bottom CB is restricted.

In this case, the light provided toward the support member DPS4 can be absorbed by the support member DPS4 without being reflected toward the diffusion plate DP in the region where the first open hole OH1 is disposed, Can be recognized by the user.

In order to prevent this, the auxiliary reflecting sheet AREF may be provided on the back surface of the base B2 in the region overlapping the supporting portion B1. The auxiliary reflecting sheet AREF can reflect the light introduced through the first open hole OH1 toward the diffusion plate DP. Thus, the fourth embodiment of the present invention has an advantage that the light efficiency can be remarkably improved. The auxiliary reflecting sheet AREF may be a white tape, but is not limited thereto.

The fastening portions B3 may be arranged to be shifted by a predetermined distance from the region corresponding to the supporting portions B1 so as to overlap the supporting portions B1 in order to provide a space in which the auxiliary reflecting sheet AREF is disposed. In other words, the fastening portion B3 may be arranged so as to be shifted from the region corresponding to the first open hole OH1 by a predetermined distance so as to overlap with the first open hole OH1. An auxiliary reflecting sheet AREF is disposed on the rear surface of the base B2 on which the fastening portions B3 are shifted. In this case, the fastening portions B3-A and B3-B may be disposed on both sides with respect to the support portion B1, respectively, in order to prevent the support member DPS4 from flowing and securely fix it.

Referring to FIG. 14 (b), the base portion B2 may be provided with a lead-in groove IG. The lead-in groove IG may be provided partially recessed inwardly from the back surface of the base portion B2. An auxiliary reflecting sheet AREF can be drawn in the lead-in groove IG. Thereby, the auxiliary reflecting sheet AREF is guided by the lead-in groove IG, and can be accurately aligned at a predetermined position. Further, as the auxiliary reflecting sheet AREF is drawn into the inlet groove IG, there is an advantage that the thickness thereof can be correspondingly reduced.

 <Fourth Embodiment>

Fig. 15 is a view for explaining the arrangement of support members according to the fifth embodiment of the present invention. Fig.

Referring to FIG. 15, 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 REF, 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. For example, the backlight unit may be divided into a plurality of regions along the lateral direction from the center portion. For example, the height of the support member (in particular, the height of the support portion) provided in the first region A1 adjacent to the center portion is disposed in a second region A2 relatively farther from the center portion with respect to the first region A1 (In particular, the height of the support portion) of the support member.

In addition, the backlight unit according to the fifth embodiment of the present invention can selectively arrange support members having different structures according to their positions. That is, in the backlight unit according to the fifth embodiment of the present invention, the support member disposed in the first region A1 and the support member disposed in the second region may have different structures.

It may be preferable that a support member including an extension having a cylindrical structure of a single structure is disposed in the second region A2 relatively far from the light source module LM and having a relatively small amount of light to be provided. That is, when the extending portion is provided in a conical shape or is provided in a double structure including a conical shape, in the second region A2 in which the light amount is relatively small, the provided light is scattered by the bottom portion of the cone having a predetermined thickness, A white spot defect in which the area is bright compared to other areas may occur. This phenomenon occurs in the second region A2 in contrast to the first region A1 in which the light amount is concentrated, which is problematic. In order to prevent this, it is preferable to arrange the second region A2 with a support member having a single-walled structure of an extended portion like the structure shown in Fig.

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 DPS: support member

Claims (25)

A light source module extending in one direction;
A reflection plate disposed under the light source module and extending in a lateral direction crossing the one direction from a central portion in which the light source module is disposed;
A cover bottom which is disposed below the reflection plate and supports the reflection plate;
A diffusion plate disposed on the light source module; And
And a support member disposed below the diffusion plate and supporting the diffusion plate,
Wherein the support member comprises:
A base portion interposed between the reflection plate and the cover bottom; And
And a support portion extending from the base portion through a first open hole formed in the reflection plate and supporting the diffusion plate.
The method according to claim 1,
The support portion
The backlight unit has a constant sectional area from the bottom to the top.
The method according to claim 1,
The support portion
A neck portion passing through the first open hole; And
And an extension extending from the neck portion,
The lower part of the extension part
And has a wider cross-sectional area than the neck portion.
The method of claim 3,
The extension
The backlight unit has a gradually decreasing cross-sectional area from the bottom to the top.
The method of claim 3,
The lower part of the extension part
And has a cross-sectional area wider than a hole area of the first open hole.
The method of claim 3,
The corner of the lower portion of the extension
A backlight unit having predetermined curvature.
The method according to claim 1,
The support portion
A neck portion passing through the first open hole;
A first extension extending from the neck portion and having a gradually decreasing cross-sectional area from a lower portion to an upper portion; And
And a second extension extending from the first extension and having a constant cross-sectional area from the bottom to the top,
A lower portion of the first extension portion
And has a wider cross-sectional area than the neck portion.
8. The method of claim 7,
A lower portion of the first extension portion
And has a cross-sectional area wider than a hole area of the first open hole.
8. The method of claim 7,
The corner of the lower portion of the first extension
A backlight unit having predetermined curvature.
The method according to claim 1,
Wherein the support member comprises:
And a fastening portion extending from the base portion toward the cover bottom to fix the support member to the cover bottom.
11. The method of claim 10,
The fastening portion
And extends through the second open hole provided in the cover bottom, and one end thereof surrounds at least a part of the back surface of the cover bottom.
11. The method of claim 10,
The fastening portion
Wherein the backlight unit is superimposed on the supporting unit.
13. The method of claim 12,
Further comprising an auxiliary reflector disposed below the base portion,
The auxiliary reflector includes:
Wherein the backlight unit overlaps the supporting unit.
14. The method of claim 13,
The auxiliary reflector includes:
Wherein the first open hole overlaps with the first open hole and has an area larger than a hole area of the first open hole.
14. The method of claim 13,
The base unit includes:
Further comprising a lead-in groove partially recessed inwardly from a back surface of the base portion,
The auxiliary reflector includes:
And is drawn into the lead-in groove.
The method according to claim 1,
The light source module includes:
A backlight unit comprising: a light source; and a lens unit for switching the direction of light provided from the light source.
The method according to claim 1,
The reflector includes:
And at least one region having a cross-sectional shape that is bent so as to have a predetermined curvature from the central portion toward the lateral direction or inclined to have a predetermined inclination.
The method according to claim 1,
The distance between the reflection plate and the diffuser plate may be,
Wherein the at least one region is gradually reduced toward the side portion.
19. A method according to any one of claims 17 to 18,
A first region and a second region that are sequentially separated from the center portion along the lateral direction,
Wherein the height of the support portion provided in the first region
And the height of the support portion in the second region is higher than the height of the support portion in the second region.
The method according to claim 1,
Wherein the support member comprises:
A backlight unit made of a transparent material.
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 cover bottom which is disposed below the reflection plate and supports the reflection plate;
A diffusion plate disposed on the light source module;
A liquid crystal display panel disposed on the diffusion plate; And
And a support member disposed below the diffusion plate and supporting the diffusion plate,
Wherein the support member comprises:
A base portion interposed between the reflection plate and the cover bottom; And
And a support portion extending through the first open hole provided in the reflection plate from the base portion and supporting the diffusion plate.
22. The method of claim 21,
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.
22. The method of claim 21,
Further comprising a floating bar disposed below the light source module,
Wherein the floating bar comprises:
A base portion; And
And a floating portion protruding from the base portion toward the diffuser plate and on which the light source module is mounted.
24. The method of claim 23,
Wherein the floating portion includes:
A seating surface on which the light source module is seated, and
And an inclined surface connecting the seating surface and the upper surface of the base portion and inclined at a predetermined angle with respect to the seating surface.
25. The method of claim 24,
At least a part of the reflection plate
And is seated on the inclined surface.

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