KR102421275B1 - Backlight unit and liquid crystal display device comprising the same - Google Patents

Abstract

The backlight unit according to the present invention includes a light source module, a reflector, a floating bar, and a diffusion plate. The light source module has a light source and a lens unit that converts the direction of light provided from the light source. The floating bar is disposed below the light source module. The reflective plate is disposed to cover at least a portion of the floating bar under the light source module. In at least one region, the reflective plate has a cross-sectional shape that is bent to have a predetermined curvature or inclined to have a predetermined inclination toward the side portion from the central portion in which the light source module is disposed. The diffuser plate is disposed over the light source module.

Description

Backlight unit and liquid crystal display including same

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

The liquid crystal display is used in portable computers such as notebook PCs, office automation equipment, audio/video equipment, indoor and outdoor advertisement displays, and the like. A liquid crystal display displays an image by controlling an electric field applied to a liquid crystal layer of a liquid crystal display panel to modulate light incident from a backlight unit (BLU).

The conventional backlight unit may be divided into a direct type and an edge type. The edge type backlight unit has a structure in which a light source is disposed to face a side surface 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, a light source irradiates light to one side of the light guide plate, and the light guide plate converts a linear light source or a point light source into a planar light source and irradiates the light to 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 overall thickness can be reduced, and thus a slim (or thin) liquid crystal display can be realized. However, in the case of an edge-type backlight unit, since a relatively large number of light sources are required, there may be a problem in that the optical characteristics are deteriorated due to heat emitted from the light source, and there are problems in cost competitiveness such as the need for a large number of light sources. have

The direct backlight unit has a structure in which a plurality of light sources are disposed under the liquid crystal display panel, and radiates light diffused through the diffusion plate to the liquid crystal display panel. The direct type backlight unit has an advantage in cost competitiveness compared to the edge type backlight unit. However, in the case of a direct backlight unit, since light sources are disposed under the diffusion plate, it is difficult to implement a slimmed liquid crystal display. That is, in the backlight unit, it is necessary to space the diffusion plate and the light sources at a certain distance in consideration of the optical gap. there is only In order to realize the slimming of the backlight unit, a method of reducing the optical gap may be considered. may be significantly lowered.

In order to improve the above problems, it is necessary to propose a backlight unit of a new type, rather than the conventional edge type or direct type backlight unit.

An object of the present invention is to provide a light-weight, slim-line liquid crystal display.

The backlight unit according to the present invention includes a light source module, a reflector, a floating bar, and a diffusion plate. The light source module has a light source and a lens unit that converts the direction of light provided from the light source. The floating bar is disposed below the light source module. The reflective plate is disposed to cover at least a portion of the floating bar under the light source module. In at least one region, the reflective plate has a cross-sectional shape that is bent to have a predetermined curvature or inclined to have a predetermined inclination toward the side portion from the central portion in which the light source module is disposed. The diffuser plate is disposed over the light source module.

The present invention has an advantage in that it is possible to provide a light-weight, slimmer backlight unit and a liquid crystal display including the same. The present invention can provide a backlight unit with significantly improved luminance uniformity and a liquid crystal display including the same.

1 is an exploded perspective view schematically showing a liquid crystal display according to the present invention.
FIG. 2 is a cross-sectional view taken along II′ of FIG. 1 .
3 is a perspective view schematically illustrating a light source module and its surrounding configuration.
4 is a view schematically illustrating a traveling direction of light emitted from a light source module.
5 is a cross-sectional view schematically illustrating a lens shape and a path of light passing through the 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 diagrams for explaining the effect of the floating bar.
10 and 11 are views for explaining a floating bar according to the first embodiment of the present invention.
12 is a view for explaining a floating bar according to a second embodiment of the present invention.
13 is a view for explaining a floating bar according to a third embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Like reference numerals refer to substantially identical elements throughout. In the following description, if it is determined that a detailed description of a known technology or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In describing various embodiments, the same components are representatively described in the introduction and may be omitted in other embodiments.

Terms including ordinal numbers such as first, second, etc. may be used to describe various elements, but the elements are not limited by the terms. The above 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 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 illustrating a light source module and its surrounding configuration. 4 is a view schematically illustrating a traveling direction of light emitted from a light source module.

1 to 3 , the liquid crystal display device according to the present invention includes a liquid crystal display panel (PNL) and a backlight unit disposed on the rear surface of the liquid crystal display panel (PNL) to irradiate light to the 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. An upper polarizing film and a lower polarizing film may be respectively disposed on the thin film transistor substrate and the opposite substrate of the liquid crystal display panel PNL. The upper polarizing film and the lower polarizing film pass only components of a specific direction among components of light irradiated from the backlight unit.

The thin film transistor substrate includes a thin film transistor array having a plurality of pixels. Pixels may be defined by a plurality of gate lines (not shown) and a plurality of data lines (not shown) crossing 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) disposed adjacent to the pixel electrode and supplied with a common voltage. may include In this case, the common electrode may be disposed on the opposite substrate according to the driving method of the liquid crystal layer. A pad portion connected to the panel driver is provided on one side of the thin film transistor substrate.

The opposite substrate may be a color filter array substrate. However, when the liquid crystal display panel PNL is implemented using a color filter on TFT (COT) or a TFT on color filter (TOC) method, the color filter may be formed on the thin film transistor substrate. The opposite substrate may be formed to have a relatively smaller area than the thin film transistor substrate, but is not limited thereto. The opposing substrate may be disposed to face the thin film transistor substrate so as to overlap an area other than the pad portion of the thin film transistor 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. For example, the opposing substrate may be positioned on the upper surface of the thin film transistor substrate, and the thin film transistor substrate may be inverted to be positioned on the opposing substrate.

The liquid crystal layer is driven by an electric field generated by a potential difference between the data voltage supplied to the pixel electrode through the data lines and the common voltage supplied to the common electrode to adjust the amount of light transmitted from the liquid crystal display panel PNL. The liquid crystal layer may be implemented in at least one mode among various liquid crystal modes. For example, the liquid crystal layer may be implemented in a twisted nematic (TN) mode, a vertical alignment (VA) mode, an in plane switching (IPS) mode, and a fringe field switching (FFS) mode.

The panel driver is connected to the pad portion provided on the thin film transistor substrate to transmit a signal for driving each pixel of the liquid crystal display panel PNL. The panel driver 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 in 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 rear surface of the liquid crystal display panel PNL and irradiates light toward the liquid crystal display panel PNL. The backlight unit includes a light source module LM, a diffusion plate DP, and a reflection 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 in the form of a bar extending long in one direction.

The light source LS may be implemented as a light emitting diode (LED) having advantages such as high efficiency, high brightness, and low power consumption. The position and arrangement density of the light sources LS may be appropriately selected in consideration of optical characteristics within 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 driver through the light source printed circuit board LP. A circuit for electrically connecting the light source LS and the light source driver is formed on the light source printed circuit board LP. The light source printed circuit board LP may extend long 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 unit may be provided to have a predetermined shape, and may function to change the traveling direction of the light provided from the light source LS and uniformly spread the light in the predetermined direction.

Specifically, the lens unit includes a bar-shaped lens LN extending long in the one direction. The lens unit may include one lens LN that is elongated in one direction. Alternatively, the lens unit may include a plurality of divided lenses LN, which may be arranged side by side in one direction. When the lens unit includes a plurality of lenses LN, processing is easy, and fastening/separating operations are easy to have advantages such as rework.

The light provided from the light source LS may be redirected in a predetermined direction by the lens LN. That is, the lens LN controls the light path so that the light provided from the light source LS is not concentrated on a specific position, but is uniformly diffused from the center to the side surface of the backlight unit provided with the light source module LM.

Light emitted from the light source module LM may be directly incident to the diffusion plate DP, may be reflected by the reflection plate REF, and may be incident to the diffusion plate DP. The 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 portion OPS positioned on the diffusion plate DP, and the light passing through the diffusion plate DP passes through the optical sheet portion OPS of the liquid crystal display panel PNL. It can be irradiated uniformly to the back side. The optical sheet unit OPS may include at least one diffusion sheet and a light collecting sheet, and may include various functional sheets such as 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 change the direction of the incident light to a predetermined direction, or in other words, to control the emission angle of the light reflected by the reflection plate REF.

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

In other words, the cross-section of the reflecting plate REF is bent at a preset curvature from the central portion in which the light source module extending in one direction is provided in the lateral direction extending in the direction crossing (or perpendicular to) the one direction. may have a shape.

The curvature may be set differently depending on the location. A cross-sectional shape of the reflector REF may be symmetrical with respect to an imaginary center line CL crossing the center. In at least one region, the distance between the reflector REF and the diffusion plate DP is gradually reduced in the lateral direction.

As another example, the cross-section of the reflection plate REF may have a shape inclined by a preset 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 decreased toward the side portion (or the side direction).

The angle may be set differently depending on the location. A cross-sectional shape of the reflector REF may be symmetrical with respect to an imaginary center line CL crossing the center.

The reflecting plate REF may be divided and provided in plurality. For example, the reflector REF may be divided into two, and may be respectively disposed on both side portions with respect to the central portion in which the light source module LM is disposed.

An air gap is provided between the reflection plate REF and the diffusion plate DP. The air gap may serve as a buffer so that the light emitted from the light source module LM is widely distributed.

The liquid crystal display panel (PNL) and the backlight unit are assembled together by a case member and 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 may be coupled to each other to accommodate the backlight unit therein.

The guide panel GP is interposed between the liquid crystal display panel PNL and the backlight unit to support the edge of the liquid crystal display panel PNL from the rear side, and to reduce the gap between the liquid crystal display panel PNL and the backlight unit. can be kept constant. The guide panel GP may have a rectangular frame shape through which a center is penetrated. The guide panel GP may be made of a plastic-based material that can be molded into a mold, such as polycarbonate, but is not limited thereto.

The cover bottom CB may support the reflective plate REF from the rear surface so that the reflective plate REF may 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 cross-section of the reflector REF has a shape bent with a preset curvature, the cross-section of the cover bottom CB may also have a shape bent with a preset curvature corresponding thereto, and the cross-section of the reflector REF is a horizontal plane. In the case of having a shape inclined by a preset angle from the , the cross section of the cover bottom CB may also have a shape inclined by a preset angle from the horizontal plane corresponding thereto.

The cover bottom CB may be made of a material having high thermal conductivity and high rigidity to smoothly dissipate heat from the panel driver and/or the light source module LM to the outside. For example, the cover bottom (CB) is aluminum, aluminum nitride (AlN), electro galvanized steel sheet (EGI), stainless (SUS), galvalume (SGLC), aluminum plated steel sheet (aka ALCOSTA), tin plated steel sheet (SPTE) It may be made of a metal material such as, for example. In addition, such a metal plate may be coated with a high-conductivity material to promote heat transfer.

The backlight unit may further include a support member (not shown) for preventing the diffusion plate DP from sagging. The support member may function to prevent the diffusion plate DP from sagging due to load and/or heat, thereby maintaining a state in which the diffusion plate DP and the reflection plate REF are spaced apart from each other by a preset interval.

The height of the support member may be different 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 for maintaining the distance between the diffusion plate DP and the reflection plate REF may be different depending on the position.

The support member may be fastened to a support such as the cover bottom CB and fixed at a preset position. The support member may be formed of a plastic-based material such as polycarbonate, 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 distributed over the entire surface of the backlight unit by the lens LN of the lens unit. Some of the light emitted from the light source module LM may be directly incident on the diffusion plate DP, and the other portion proceeds toward the reflection plate REF and is reflected by the reflection plate REF to the diffusion plate DP. can be hired The propagation direction of the light emitted from the light source module LM and the degree of distribution of the amount of light may be controlled by the lens LN provided in the lens unit.

In the present invention, the light from the light source LS does not go directly to the diffusion plate DP like the conventional direct backlight unit, but is dispersed through the lens LN of the lens unit and then controlled to proceed to the diffusion plate DP. do. Accordingly, the present invention has the advantage of providing a slimmer backlight unit and a liquid crystal display including the same because it is necessary to secure a wide optical gap as in the prior art in order to ensure luminance uniformity.

5 is a cross-sectional view schematically illustrating a lens shape and a path of light passing through the 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 symmetrical cross-sectional shape based on an imaginary center line CL crossing the center in the vertical direction. The light source LS disposed under the lens LN may be disposed to correspond to the center line CL. Accordingly, the light emitted from the light source LS may be split in different directions, and may be uniformly emitted toward both side surfaces P2 .

Most of the light provided from the light source LS is reflected by the upper surface P1 of the lens LN and travels toward the side surface of the backlight unit. The upper surface P1 of the lens LN may function to induce total reflection of the light provided from the light source LS and suppress the normally emitted light. The vertically emitted light refers to light that is transmitted or refracted without being reflected by the upper surface P1 of the lens LN among the light provided from the light source LS and directly proceeds toward the diffusion plate DP. The upper surface P1 of the lens LN may be provided to have a predetermined curvature to control the total reflection direction and light diffusion distribution.

The side surface P2 of the lens LN may serve to transmit most of the light reflected from the upper surface P1 of the lens LN and to totally reflect some 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, and the upper portion UA of the lens LN ) can be proceeded towards. That is, in the present invention, since the amount of light traveling to the upper portion UA of the lens LN can be controlled by adjusting the shape of the side surface P2 of the lens LN, the upper portion UA of the lens LN is It is possible to improve the mura phenomenon that may occur. Accordingly, the present invention has an advantage in that it is possible to provide a backlight unit having improved luminance uniformity and a liquid crystal display including the same.

The shape of the side surface P2 of the lens LN may be selected in consideration of a required light emission angle. For example, when the lens unit includes a plurality of lenses LN, the shape of the side surface P2 of one lens LN and the other lens LN may be different, and in this case, the shape of the side surface P2 may be selected in consideration of an emission angle of light. The emission angle may be selected in consideration of the direction of light finally emitted from the lens LN.

The lower surface P3 of the lens LN may serve to transmit a portion of the light reflected from the side surface P2 of the lens LN and reflect the other portion to the upper portion UA of the lens LN. In the present invention, by using the light reflected by the side surface P2 and the lower surface P3 of the lens LN, the amount of light propagating to the upper portion UA of the lens LN can be controlled, and accordingly, the lens LN ) can improve the mura in the upper part. In addition, most of the light provided from the lens LN is incident on the reflective plate REF disposed on the cover bottom CB, and the lower surface P3 of the lens LN is reflected by the reflective plate REF to the lens LN. ) can function to control the optical path of the re-incident light. The lower surface P3 of the lens LN may be provided so that a cross section thereof has a predetermined curvature in order to perform the above-described function.

A recess RC (recess) may be further provided in the lower surface P3 of the lens LN. The recess RC may be provided in a form partially recessed inward from the lower surface P3 of the lens LN. The cross-sectional shape of the recess RC may be implemented in a “∧” shape having a curvature. The shape of the recess RC may be selected in consideration of the curvature of the upper surface P1 of the lens LN that induces total reflection of light. As the recess RC is provided, the amount of light incident from the light source LS to the lens LN may increase.

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

According to the present invention, since the lens unit having the above-described shape is included, light can be uniformly provided to the entire diffuser plate DP with a small number of light sources LS provided at the center of the backlight unit.

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

6 and 7 are views for explaining a floating bar according to the present invention. 8 and 9 are diagrams 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. Floating bar (FB) is a metal such as aluminum, aluminum nitride (AlN), electro galvanized steel (EGI), stainless (SUS), galvalume (SGLC), aluminum plated steel plate (aka ALCOSTA), tin plated steel plate (SPTE), etc. It can be made of material.

The base part BP may be fastened to the cover bottom CB. For example, the base part BP may 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. it might be The base part BP may be accommodated in the forming part FOA provided on the cover bottom CB.

The base portion BP is provided to have a large area, and preferably has a sufficient contact area with the cover bottom CB. Accordingly, in a preferred embodiment of the present invention, the base portion BP can be stably fixed to the cover bottom CB, and a heat dissipation path of heat generated from the light source module LM can be sufficiently secured.

The floating part FP is provided to have a predetermined thickness and is provided to protrude from the base part BP. The floating part FP may be provided to have a smaller area than the base part BP, and may be provided in the center of the base part BP. The upper surface of the floating bar FB includes a seating surface SP and an inclined surface CP.

The seating surface SP is provided to sufficiently secure a path of light toward the reflection plate REF among the light emitted from the light source module LM, and for this purpose, the light source module LM positioned on the seating surface SP ( In particular, the height of the lens unit) is controlled. On the seating surface SP, the light source module LM is mounted. For example, as illustrated, the light source printed circuit board LP may be disposed on the seating surface SP, and the light source LS and the lens LN may be disposed on the light source printed circuit board LP.

The inclined surface CP is provided to direct some of the light emitted from the light source module LM to a target area, and for this purpose, the inclination of the reflecting plate REF located on the inclined surface CP is controlled (FIG. 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 part BP. The inclined surface CP is inclined by a preset angle with respect to the seating surface SP. A portion of the reflective plate REF is mounted on the inclined surface CP. That is, a portion of the reflective plate REF is mounted on the inclined surface CP in a state of being inclined at a predetermined angle corresponding to the inclination of the inclined surface CP.

More specifically, referring to FIG. 7A , the width W1 of the seating surface SP is set to be narrower than the width W2 of the lens LN of the lens unit. This means that the lens LN is provided to cover at least a portion of the seating surface SP and the inclined surface CP. Accordingly, the light propagating toward the floating bar FB among the light whose optical path is switched by the lens LN may travel toward the inclined surface CP, and such light may be transmitted to the reflective plate ( REF) and can be directed to the target area.

Referring to (b) of FIG. 7 , the width W1 of the seating surface SP is the same as 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 be provided more narrowly. That is, when the width W1 of the seating surface SP is set to be wider than the width W3 of the light source printed circuit board LP so that a part of the seating surface SP is exposed, the reflectance of the seating surface SP substrate Due to the difference in reflectance between the REF and the reflector REF, the corresponding region may be recognized by the user as a dark part, and thus may be a factor of lowering display quality. Therefore, it may be preferable to completely shield the seating surface SP using the light source printed circuit board LP.

FIG. 8(a) shows the light output distribution in the structure without the floating bar FB, and FIG. 8(b) shows the light output in the structure in which the floating bar FB is provided but the inclined surface CP is not included. distribution is shown.

Referring to FIG. 8 , a distribution of light emitted from the light source module LM may be divided into a first area A1 and a second area A2 . The first area A1 is an area in which light emitted from the light source module LM and traveling directly to the diffusion plate DP is distributed, and the second area A2 is emitted from the light source module LM and the reflection plate REF. This is an area in which the light that travels to the diffusion plate DP is distributed after being reflected by the . When there is no floating bar FB or when the floating bar FB does not include the inclined surface CP, the third area ( A3) will exist. In this case, the third area A3 may be visually recognized by the user as a dark part, and may be a factor that significantly deteriorates the display quality.

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

Figure 9 (a) shows the light output distribution in a preferred embodiment of the present invention provided with a floating bar (FB) having an inclined surface (CP), Figure 9 (b) is in the preferred embodiment of the present invention. The luminance profile is shown.

Referring to Figure 9 (a), in the case of a preferred embodiment of the present invention, the third area (A3) to target the light provided from the light source module (LM) by providing a floating bar (FB) having an inclined surface (CP) It can be seen that the luminance uniformity can be improved accordingly. Referring to (b) of FIG. 9 , the luminance inflection point has disappeared compared to that of FIG.

<First embodiment>

10 and 11 are views for explaining a floating bar according to the first embodiment of the present invention.

The floating bar FB according to the first embodiment of the present invention includes a stopper STP. The stopper STP may guide the position of the reflective plate REF seated on the floating bar FB, and may restrict and limit the flow of the reflective plate REF. When the reflector REF is shifted without being fixed in position, at least a portion of the floating bar FB may be exposed, and the exposed portion may be recognized by the user as a dark spot. Accordingly, the first embodiment of the present invention includes a stopper STP for limiting the movement of the reflection plate REF.

For example, referring to FIG. 10 , the stopper STP may be implemented in the form of a protrusion PD protruding from the upper surface of the floating bar FB. As one end of the reflector REF is disposed in contact with one side of the protrusion PD, its position may be guided and its movement may be limited. However, when the stopper STP is provided in the form of a protrusion PD, the upper surface of the protrusion PD may not be shielded by the reflector REF and may be exposed as it is, and the exposed upper surface of the protrusion PD is provided to the user. It can be acknowledged as a dark part.

As another example, referring to FIG. 11 , the stopper STP may be implemented as a step RS provided at a boundary between the seating surface SP and the inclined surface CP constituting the floating part FP. As one end of the reflector REF is disposed in contact with the step RS, its position may be guided and its movement may be limited. In this case, the exposed floating bar FB area is reduced compared to the structure in which the stopper STP is provided in the form of the protrusion PD. Accordingly, since the area recognized by the user as a dark part can be reduced, display characteristics can be remarkably improved.

The step RS may be provided by a groove OH provided on the inclined surface CP. The groove OH may be provided by being partially recessed inward from the inclined surface CP of the floating bar FB. Since the inclined surface CP is inclined to have a predetermined inclination, when the groove OH is formed in the inclined surface CP, a step RS to which one end of the reflecting plate REF may abut may be provided.

<Second embodiment>

12 is a view for explaining a floating bar according to a second embodiment of the present invention.

Referring to (a) of FIG. 12 , the floating bar FB according to the present invention has the height of the seating surface SP, the inclination of the inclined surface CP, and the area of the base part BP under the above-described conditions. Since it may be preset, the shape of the floating bar FB may be determined as shown. As such, in the case of the floating bar FB, it may be molded by an extrusion method, and as shown in FIG. can occur

Referring to FIG. 12B , in order to improve this, the floating bar FB according to the second embodiment of the present invention includes one or more grooves GR. The groove GR may be provided to be partially recessed inward from the rear surface of the floating bar FB. The groove GR may be formed to correspond to a central portion having a relatively thick thickness, that is, a region in which the floating portion FP is located. According to the second embodiment of the present invention, the thickness deviation between the central portion and the side portion of the floating bar FB may be reduced by including the groove GR. Accordingly, it is possible to improve the bending defect during extrusion molding, it has the advantage of significantly improving product reliability.

<Third embodiment>

13 is a view for explaining a floating bar according to a third embodiment of the present invention.

Referring to FIG. 13 , the floating bar FB according to the third exemplary embodiment includes a concave portion CC for securely fastening to the cover bottom CB. The concave portion CC may be provided in the form of a groove partially recessed inward from the rear surface of the floating bar FB, or may be provided in the form of a hole completely penetrating the thickness of the floating bar FB as shown.

The cover bottom CB includes a convex portion CV protruding toward the floating bar FB. The convex portion CV of the cover bottom CB is introduced into the concave portion CC of the floating bar FB. The convex portion CV of the cover bottom CB and the concave portion CC of the floating bar FB may be fittedly coupled.

As the convex part CV of the cover bottom CB and the concave part CC of the floating bar FB are fastened, the movement of the floating bar FB may be constrained and limited. In the first embodiment of the present invention, since the position of the floating bar FB can be firmly fixed at a preset position, the optical characteristic deteriorates as the floating bar FB on which the light source module LM is seated is shifted. can prevent

Although not shown, the cover bottom CB may include a concave portion, and the floating bar FB may include a convex portion protruding toward the cover bottom CB. The convex portion of the floating bar FB may be introduced into the concave portion of the cover bottom CB.

Those skilled in the art through the above description will be able to make various changes and modifications without departing from the technical spirit of the present invention. Accordingly, 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 part FP: Floating part
SP : Seating surface CP : Inclined surface
DP: diffuser plate

Claims (15)

a light source module having a light source and a lens unit for converting a direction of light provided from the light source;
a floating bar disposed under the light source module;
It is arranged to cover at least a part of the floating bar under the light source module, and in at least one area, from the central portion where the light source module is disposed to the side portion, is bent to have a predetermined curvature or inclined to have a predetermined inclination cross-sectional shape. having a reflector; and
It includes a diffusion plate disposed on the light source module,
A lower surface of the lens unit is provided with a recess recessed inwardly from the lower surface, and the light source is accommodated in the recess.
The method of claim 1,
The distance between the reflector and the diffusion plate,
In the at least one region, the backlight unit gradually decreases toward the side portion.
The method of claim 1,
The floating bar is
base part; and
and a floating part protruding from the base part toward the diffusion plate and on which the light source module is seated.
4. The method of claim 3,
The floating part,
a seating surface on which the light source module is seated, and
A backlight unit connecting the seating surface and an upper surface of the base part, and including an inclined surface inclined at a preset angle with respect to the seating surface.
5. The method of claim 4,
At least a portion of the reflector,
The backlight unit is seated on the inclined surface.
6. The method of claim 5,
The lens unit,
It extends in one direction and includes at least one lens provided in the form of a bar,
The lens is
A backlight unit covering at least a portion of the seating surface and the inclined surface.
6. The method of claim 5,
The floating bar is
and a protrusion protruding from a boundary between the seating surface and the inclined surface.
8. The method of claim 7,
One end of the reflector,
A backlight unit in contact with the protrusion.
6. The method of claim 5,
The floating bar is
A backlight unit comprising a groove provided at a boundary between the seating surface and the inclined surface.
10. The method of claim 9,
One end of the reflector,
A backlight unit in contact with the step of the seating surface and the inclined surface provided by the groove.
6. The method of claim 5,
The floating bar is
and at least one groove provided to be partially recessed inward from a rear surface of the floating bar.
6. The method of claim 5,
Supporting the reflection plate under the reflection plate, further comprising a cover bottom having a convex portion protruding toward the reflection plate,
The floating bar,
and a concave portion into which the convex portion is introduced.
6. The method of claim 5,
The light source module,
Further comprising a light source printed circuit board disposed under the light source,
The width of the seating surface is
The backlight unit, which is set to be the same as the width of the light source printed circuit board or narrower than the width of the light source printed circuit board.
a light source module having a light source and a lens unit for converting a direction of light provided from the light source;
a floating bar disposed under the light source module;
It is arranged to cover at least a part of the floating bar under the light source module, and in at least one area, from the central portion where the light source module is disposed to the side portion, is bent to have a predetermined curvature or inclined to have a predetermined inclination cross-sectional shape. having a reflector; and
a diffusion plate disposed on the light source module; and
a liquid crystal display panel disposed on the diffusion plate;
A lower surface of the lens unit is provided with a recess recessed inwardly from the lower surface, and the light source is accommodated in the recess.
15. The method of claim 14,
The lens unit,
It extends in one direction and includes at least one lens provided in the form of a bar,
The lens is
A liquid crystal display device that reflects some of the light provided from the light source toward the reflecting plate and transmits another portion.

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