KR20080056365A - Display apparatus - Google Patents

Abstract

A display device is provided to fix a spot light source to a light guide panel by a combining member so that the light transmission center of the spot light source is met with the light receiving center of the light guide panel exactly. A display panel displays an image. An FPCB(Flexible Printed Circuit Board) is connected with an end of the display panel and bent toward the lower side of the display panel. A light guide panel(400) is located at the lower side of the display panel and has a receiving groove formed at a side and a fixing protrusion formed within the receiving groove. At least one optical unit(300) is arranged at a side of the FPCB opposite to the lower side of the display panel . The optical unit has a spot light source arranged at the receiving groove and for emitting the light beam. A fixing member(320) supports the spot light source and is combined with the fixing protrusion. A combining bottom member(322) is formed at the lower side of the spot light source. A hooking member(324) is extended vertically from both ends of the combining bottom member and combined with the fixing protrusion.

Description

Display device {DISPLAY APPARATUS}

1 is an exploded perspective view illustrating a display device according to an exemplary embodiment of the present invention.

FIG. 2 is a combined perspective view of the display device of FIG. 1.

3 is a perspective view illustrating a fastening relationship between a light source unit and a light guide plate.

4 is a cross-sectional view taken along the line II ′ of FIG. 3.

5 is a cross-sectional view illustrating the fastening method of FIG. 3.

6 is a perspective view illustrating another embodiment of FIG. 3.

<Description of the symbols for the main parts of the drawings>

100: display panel 200: flexible circuit board

300: light source unit 310: point light source

320: fastening member 322: fastening bottom

324: hook 400: light guide plate

410: receiving groove 420: fixing protrusion

600: mold frame 700: storage container

800: display device

The present invention relates to a display device, and more particularly, to a display device capable of improving light transmission efficiency.

In general, liquid crystal displays are thinner, lighter, and have lower power consumption than other flat panel displays such as PDPs and CRTs.

Such a liquid crystal display device requires a backlight assembly for supplying additional light because the liquid crystal display panel displaying an image is a non-light emitting device that does not emit light by itself.

In particular, the backlight assembly employed in small and medium-sized products such as mobile communication terminals uses small sized light emitting diodes (LEDs) as light sources. Specifically, the backlight assembly includes a light emitting diode, a flexible circuit board for a light source in which the light emitting diode is disposed, and a light guide plate for guiding light from the light emitting diode toward the liquid crystal display panel.

Recently, instead of using a separate flexible printed circuit board for a light source, a method of directly mounting light emitting diodes on a main flexible printed circuit board connected to the liquid crystal display panel is used to drive the liquid crystal display panel. In this way, the cost of the liquid crystal display device can be reduced by removing the flexible circuit board for the light source.

However, in the structure in which the light emitting diodes are mounted on the main flexible circuit board, the separation space is generated between the light emitting diode and the light guide plate due to the floating phenomenon of the main flexible circuit board. Accordingly, the center of the light exit surface of the light emitting diode and the center of the light entrance surface of the light guide plate do not correspond exactly, resulting in a problem of low light transmission efficiency.

Therefore, the technical problem of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a display device that can improve the light transmission efficiency by matching the center of the light source and the light guide plate.

In order to achieve the above object of the present invention, a display device according to an embodiment includes a display panel for displaying an image, a flexible circuit board connected to one end of the display panel and bent to the lower side of the display panel. At least one light guide plate disposed on the lower side and having a receiving groove formed on one side and a fixing protrusion formed in the receiving groove and at least one surface of the flexible circuit board facing the lower portion of the display panel is disposed in the receiving groove. It includes a light source unit for emitting a light and a fastening member for supporting the point light source and coupled to the fixing projections.

At this time, the fastening member may comprise an engagement portion that is coupled to and extends vertically, the fixing protrusion from the lower fastening the bottom part and both the engaging portions formed on the bottom of the point light source. In addition, the fastening member may be made of a metallic material having elasticity.

According to such a display device, the center of the emission surface of the point light source and the incident surface of the light guide plate are aligned through the fastening member, thereby maximizing the transmission efficiency of light incident from the point light source to the light guide plate.

Hereinafter, with reference to the accompanying drawings, it will be described in detail the present invention.

1 is an exploded perspective view of a display device according to an exemplary embodiment. FIG. 2 is a combined perspective view of the display device of FIG. 1.

1 and 2, the display device 800 according to an exemplary embodiment of the present invention may include a display panel 100, a flexible circuit board 200, a light guide plate 400, a light source unit 300, and a mold frame ( 600 and the storage container 700.

The display panel 100 includes a first substrate 110, a second substrate 120 facing the first substrate 110, and a liquid crystal layer interposed between the first substrate 110 and the second substrate 120. H) and display an image.

The first substrate 110 is a substrate in which a thin film transistor (TFT), which is a switching element, is formed in a matrix form. A data line and a gate line are respectively connected to the source terminal and the gate terminal of the TFTs, and a pixel electrode made of a transparent conductive material is connected to the drain terminal.

The second substrate 120 is disposed to face the first substrate 110, and is a substrate in which RGB pixels for realizing color are formed in a thin film form. A common electrode made of a transparent conductive material is formed on the second substrate 120 to face the pixel electrode formed on the first substrate 110.

When power is applied to the gate terminal of the TFT in the display panel 100 and the TFT is turned on, an electric field is formed between the pixel electrode and the common electrode. The arrangement of the liquid crystal molecules disposed between the first substrate 110 and the second substrate 120 is changed by the electric field, and the light transmittance is changed according to the arrangement change of the liquid crystal molecules to display an image of a desired gray scale. Can be.

The display panel 100 may further include a driving chip 130 mounted on the first substrate 110. The driving chip 130 generates a driving signal for driving the display panel 100 in response to various control signals applied from the outside. For example, the driving chip 130 may be electrically connected to the first substrate 110 through an anisotropic conductive film (ACF) (not shown).

The flexible circuit board 200 is connected to one end of the first substrate 110 to apply various control signals to the display panel 100. The flexible circuit board 200 may be electrically connected to the first substrate 110 through the anisotropic conductive film as an example.

In the present invention, since the flexible circuit board 200 is flexible, the flexible circuit board 200 may be bent from the first substrate 110 to the lower side of the display panel 100. For example, the flexible circuit board 200 may be bent to the lower side of the mold frame 600 and may be accommodated inside the storage container 700.

The light guide plate 400 is disposed under the display panel 100. The light guide plate 400 guides the path of the light emitted from the light source unit 300 toward the display panel 100 and emits the light. The light guide plate 400 may be made of a polymethyl methacrylate (PMMA) material having excellent light transmittance and strength to minimize light loss. For example, the light guide plate 400 may have a rectangular plate shape and may include an incident surface 401, an emission surface 402, and a reflective surface 403. In contrast, the light guide plate 400 may have a wedge shape in which the thickness decreases as the light guide plate 400 moves away from the light source unit 300.

Specifically, the light guide plate 400 faces the light source unit 300 and is perpendicular to the incident surface 401 and the incident surface 401 to which the light generated from the light source unit 300 is incident, and directs the light toward the display panel 100. An emitting surface 402 to emit, and a reflecting surface 403 facing the emitting surface 402 and for reflecting light toward the emitting surface 402. A reflective pattern (not shown) may be formed on the reflective surface 403 to reflect incident light onto the emission surface 402.

As in an exemplary embodiment of the present invention, an accommodation groove 410 and a fixing protrusion 420 (see FIG. 2) may be formed on one side surface of the light guide plate 400, that is, the incident surface 401. The fixing protrusion 420 may be formed inside the receiving groove 410.

For example, the accommodating grooves 410 may be formed to be spaced apart from each other in the longitudinal direction of the incident surface 401. The light source unit 300 is disposed inside the receiving groove 410, and the light source unit 300 may be in close contact with the incident surface 401 in combination with the fixing protrusion 420. Accordingly, the light source unit 300 may be disposed in parallel with the incident surface 401 of the light guide plate 400. Specific shapes of the receiving groove 410 and the fixing protrusion 420 will be described later with reference to FIG. 3.

The light source unit 300 is electrically connected to the flexible circuit board 200 to generate light by receiving a driving voltage from the outside. At least one light source unit 300 may be disposed on one surface of the flexible circuit board 200 facing the lower portion of the display panel 100. The number of light source units 300 is determined according to the size of the display panel 100 and the required brightness. The light source unit 300 may be disposed on one side of the light guide plate 400 by bending the flexible circuit board 200. The light source unit 300 may be disposed in plurality along the incident surface 401 of the light guide plate 400.

As in one embodiment of the present invention, the light source unit 300 may include a point light source for emitting light and a fastening member coupled to the fixing protrusion 420 to support the point light source. Each light source unit 300 may be accommodated in the receiving groove 410 and may be fixed in the receiving groove 410 by coupling the fastening member to the fixing protrusion 420. As such, the light source unit 300 is directly coupled with the light guide plate 400 to integrate the light source unit 300 and the light guide plate 400, thereby maximizing light transmission efficiency from the light source unit 300 to the light guide plate 400. have. A detailed description thereof will be described later with reference to FIG. 3.

The mold frame 600 assembles the light guide plate 400 and the light source unit 300 into one, and surrounds the outside of the display panel 100. That is, the mold frame 600 couples the display panel 100 to the upper side of the light guide plate 400. For example, the mold frame 600 may have a rectangular frame shape with an opening therein. The mold frame 600 may be coupled to the storage container 700 by, for example, hook coupling.

The storage container 700 includes a bottom plate 710 and side walls 720. The bottom plate 710 has a rectangular frame shape. Sidewalls 720 extend from an edge of the bottom plate 710 to engage with the mold frame 600. Thus, the storage container 700 may form a storage space for accommodating the flexible circuit board 200 and the light guide plate 400 on which the light source unit 300 is disposed. The storage container 700 may be formed of, for example, a metal having high strength and low deformation.

Looking at the assembly process of the display device 800 as in the present embodiment, first, the light guide plate 400 and the display panel 100 are disposed inside the mold frame 600. Next, the mold frame 600 is connected to one end of the display panel 100 so that the flexible circuit board 200 having the light source unit 300 mounted thereon faces the reflective surface 403 of the light guide plate 400. Bend downwards. Subsequently, the portion where the light source unit 300 is disposed in the flexible circuit board 200 is pushed upwards by pushing upward. Thereafter, the storage container 700 and the mold frame 600 are coupled to each other so that the bottom plate 710 of the storage container 700 covers the bent flexible circuit board 200.

The display device 800 may further include a reflective sheet 510 disposed under the light guide plate 400. The reflective sheet 510 reflects light leaking into the lower portion of the light guide plate 400 into the light guide plate 400 to improve light utilization efficiency. The reflective sheet 510 is made of a material having high light reflectance.

In addition, the display device 800 may further include at least one optical sheet 520 disposed on the light guide plate 400. For example, the optical sheet 520 may include a diffusion sheet for diffusing light emitted from the light guide plate 400 and at least one prism sheet for condensing light emitted from the light guide plate 400 in a front direction. .

3 is a perspective view illustrating a fastening relationship between a light source unit and a light guide plate. 4 is a cross-sectional view taken along the line II ′ of FIG. 3. 5 is a cross-sectional view illustrating the fastening method of FIG. 3.

2, 3 and 4, as in the embodiment of the present invention, the receiving groove 410 and the fixing projection 420 may be formed in the incident surface 401 of the light guide plate 400.

The receiving groove 410 has a first side surface 411 extending from the incident surface 401, a second side surface 412 facing the first side surface 411, and a first side surface 411 and a second side surface 412. ) And a light incident surface 413 facing the light source unit 300. The light source unit 300 is disposed inside the receiving groove 410. That is, the light source unit 300 may be disposed between the first side surface 411 and the second side surface 412 to face the light incident surface 413.

A fixing protrusion 420 coupled to the light source unit 300 may be formed in the accommodation groove 410. As in the present embodiment, the fixing protrusion 420 may be formed on the first and second side surfaces 411 and 412 of the receiving groove 410. The fixing protrusion 420 may protrude in the direction of the light source unit 300 from the first and second side surfaces 411 and 412. The fixing protrusion 420 may extend from the body of the light guide plate 400 to protrude.

Meanwhile, the light source unit 300 is mounted on the flexible circuit board 200 and disposed in the accommodation groove 410 of the light guide plate 400. As in an embodiment of the present invention, the light source unit 300 may include a point light source 310 for emitting light and a fastening member 320 for supporting the point light source 310.

The point light source 310 may include a light emitting chip emitting light and a mold case covering and protecting the light emitting chip. The mold case may be made of a transparent epoxy resin material. The point light source 310 may be, for example, a light emitting diode (LED). A power pad part 311 may be formed on the bottom surface of the point light source 310 to extend from the fastening member 320 and to receive power from the flexible circuit board 200.

The fastening member 320 supports the point light source 310 and is coupled with the fixing protrusion 420. For example, the fastening member 320 may be fixed by soldering to the flexible circuit board 200. The fastening member 320 may include a fastening bottom part 322 disposed below the point light source 310 and a pair of locking parts 324 formed at both ends of the fastening bottom part 322.

The fastening bottom part 322 may support the lower portion of the point light source 310 and may be electrically connected to the flexible circuit board 200. The fastening bottom part 322 may have, for example, a plate shape covering the lower surface of the point light source 310 or a bar shape extending in parallel from the lower surface of the point light source 310.

The catching portion 324 extends vertically from both sides of the fastening bottom portion 322, and is a portion that is coupled to the fixing protrusion 420. In one example, the locking portion 324 may have a hook shape. Such a hook-shaped locking portion 324 may be caught on the upper side of the fixing protrusion 420.

In this embodiment, the locking portion 324 may be formed at both ends of the fastening bottom portion 322 to face the first and second side surfaces 411 and 412 of the receiving groove 410. That is, the locking portion 324 may have a hook shape bent in the direction of the first and second side surfaces 411 and 412, respectively.

On the other hand, the fastening member 320 of the present embodiment may be made of a material having elasticity for easy assembly. In addition, the fastening member 320 may be made of a metal material for electrically connecting the point light source 310 and the flexible circuit board 200. For example, the fastening member 320 may be made of an iron material having elasticity.

In addition, as in the present embodiment, the lower surface 421 of the fixing protrusion 420 may be spaced apart from the flexible circuit board 200 disposed below the fixing protrusion 420. The lower surface 421 of the fixing protrusion 420 may have an inclined shape with respect to the surface of the flexible circuit board 200.

For example, the lower surface 421 of the fixing protrusion 420 may be inclined to form a predetermined angle with the upper surface from the upper surface of the fixing protrusion 420. For example, the entire surface of the lower surface 421 of the fixing protrusion 420 or a partial region adjacent to the locking portion 324 may be inclined. As such, as the lower surface 421 of the fixing protrusion 420 is formed as an inclined surface, the locking portion 324 can be easily pushed up from the lower side of the fixing protrusion 420 upward. Alternatively, the lower surface 421 of the fixing protrusion 420 may be formed in a curved surface or a plane.

Referring to FIGS. 2, 4, and 5, the assembly process of the display device 800 will be described. The flexible circuit board 200 may be displayed so that the light source unit 300 may be disposed inside the receiving groove 410. It is bent to the lower side of the panel 100. Subsequently, the portion where the light source unit 300 is disposed in the flexible circuit board 200 is pressed in the direction of the display panel 100. Subsequently, the fastening member 320 of the light source unit 300 is coupled to the fixing protrusion 420 formed inside the receiving groove 410. Specifically, after the locking portion 324 is in contact with the lower surface 421 of the fixing protrusion 420, the light source unit 300 is pushed upward. At this time, the hook-shaped engaging portion 324 extending to the outside is folded by the elastic and then deformed to the original shape, it can be seated on the upper side of the fixing protrusion 420. Accordingly, the light source unit 300 may be fixed inside the accommodating groove 410 such that the light exit center of the point light source 310 and the light incident center of the light guide plate 400 coincide with each other.

As in the present invention, by engaging the engaging portion 324 with the fixing projections 420 of the light guide plate 400, the point light source 310 supported by the fastening member 320 to the receiving groove 410 of the light guide plate 400 ) Can be fixed. Thus, the light source unit 300 can be prevented from flowing in the vertical direction of the light guide plate 400. Accordingly, the transmission efficiency of light emitted from the point light source 310 and incident on the light guide plate 400 may be maximized.

6 is a perspective view illustrating another embodiment of FIG. 3. In FIG. 6, the rest of the structure except for the arrangement relationship between the locking portion and the fixing protrusion is the same as that shown in FIG. 2, and thus the detailed description thereof will be omitted.

Referring to FIG. 6, the fastening member 320 includes a locking portion 324 extending vertically from both sides of the locking bottom portion 322, and a locking portion 324 in the receiving groove 410 of the light guide plate 400. The fixing protrusion 420 is coupled to the formed.

As in this embodiment, the locking portion 324 may be formed at both ends of the fastening bottom portion 322 to face the light incident surface 413 of the receiving groove 410. That is, the locking portion 324 may have a hook shape that is bent toward the light incident surface 413.

Meanwhile, the fixing protrusion 420 may be formed at both ends of the light incident surface 413. That is, the fixing protrusion 420 may be formed at a position corresponding to the locking portion 324, that is, facing the locking portion 324. In addition, the lower surface 421 of the fixing protrusion 420 of the present exemplary embodiment may have an inclined shape with respect to the flexible circuit board 200 to facilitate assembly with the locking portion 324 as described above.

As such, the fixing protrusion 420 is formed at a position corresponding to the locking portion 324 to couple the locking portion 324 to the fixing protrusion 420 in the process of inserting the light source unit 300 into the light guide plate 400. You can. Accordingly, due to the floating phenomenon of the flexible circuit board 200, the light source unit 300 is prevented from flowing upward and downward, and thus the light exit surface of the point light source 310 and the light incident surface 413 of the light guide plate 400 are prevented. Can match exactly.

As described above, by fixing the point light source to the light guide plate using the fastening member, the light exit center of the point light source and the light incident center of the light guide plate can be exactly matched. Accordingly, the light transmission efficiency from the point light source can be maximized to improve the luminance and luminance uniformity of the display device.

Although described above with reference to the embodiments, those skilled in the art can be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below. I can understand.

Claims (9)

A display panel displaying an image; A flexible circuit board connected to one end of the display panel and bent to the lower side of the display panel; A light guide plate disposed under the display panel and having an accommodation groove formed on one side and a fixing protrusion formed in the accommodation groove; And At least one light source is disposed on one surface of the flexible circuit board facing the lower portion of the display panel, and has a point light source disposed in the receiving groove to emit light and a fastening member supporting the point light source and coupled to the fixing protrusion. A display device comprising a unit. The method of claim 1, wherein the fastening member A fastening bottom portion formed below the point light source; And And a latching portion extending vertically from both sides of the fastening bottom portion and engaged with the fixing protrusion. The display device of claim 2, wherein the locking portion has a hook shape. The display device of claim 1, wherein a lower surface of the fixing protrusion facing the flexible printed circuit board is inclined with respect to the flexible printed circuit board. According to claim 1, wherein the receiving groove comprises a first side, a second side facing the first side, and a light incident surface that connects the first side and the second side, facing the point light source Display device characterized in that. The display device of claim 5, wherein the fixing protrusion is formed on the first and second side surfaces. The display device of claim 5, wherein the fixing protrusion is formed at both ends of the light incident surface. The display device of claim 1, wherein the fastening member is made of a metallic material having elasticity. The display device of claim 1, wherein the fastening member electrically connects the point light source and the flexible circuit board.

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