KR20080076258A - Flat-light unit and liquid crystal display device with the same - Google Patents

Abstract

A surface light source unit and an LCD(Liquid Crystal Display) comprising the same are provided to simplify the structure and working process of the surface light source unit by directly installing holders for fixing lamps on a bottom case. A plurality of tube-typed lamps(230) are driven in parallel. A bottom case(210) receives the lamps. Conductive patterns(214) are formed in regions on the bottom case correspondingly to both electrodes of each of the lamps. A plurality of holders(216) are respectively installed at the conductive patterns. The holders fix the lamps so that the lamps are electrically connected to corresponding conductive patterns. A lamp-driving circuit generates a lamp-driving voltage to be supplied to the conductive patterns. Connection outlets(218) are installed through the bottom case while the connection outlets are electrically contacted with the corresponding conductive patterns. Connection plugs(272) are connected to the lamp-driving circuit and inserted in the corresponding connection outlets, thereby electrically connecting the lamp-driving circuit to the corresponding connection outlets.

Description

Flat light unit and liquid crystal display device including the same

In order to better understand the drawings used in the detailed description of the invention, a brief description of each drawing is provided.

1 is an exploded perspective view illustrating a liquid crystal display device including a conventional flat light source unit.

2 is an exploded perspective view of a liquid crystal display including a planar light source unit according to an exemplary embodiment of the present invention.

3 is a plan view illustrating a state of a bottom case to which lamps are fastened.

4 is a cross-sectional view illustrating a cross section taken along the line AA ′ of the bottom case of FIG. 3.

`` Explanation of symbols for main parts of drawings ''

10,100: liquid crystal panel 12,110: top case

20,200: backlight unit 22,210: bottom case

24,220: Reflective Sheet 26A, 26B: Holder PCB

27A: insulated substrate 27B, 214: conductive pattern

27C, 216 Holder 28,230 Tube lamp

30,240: Mold frame 32,250: Optical sheet

34,260: Support Main 36,270: Lamp Drive PCB

36A: Wire 38,280: PCB Cover

212: insulation layer pattern 218: connection outlet

219: fixing protrusion 272: connection plug.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source unit for emitting light, and more particularly, to a flat light source unit for generating light that proceeds uniformly in a plane and a liquid crystal display including the same.

Recently, a flat light source unit is mainly used as a backlight unit of a liquid crystal display device which is one of flat panel display devices. As the screen size of the liquid crystal display device increases, the planar light source unit is also required to uniformly irradiate light of the greatest intensity possible on a large plane.

To this end, a plan in which a plurality of tubular lamps are arranged side by side in the planar light source unit is adopted. In addition, in order to simplify the lamp driving circuit of a planar light source unit including a plurality of tubular lamps, a parallel-driven tubular lamp called "External Electrode Fluourescent Lamp" (hereinafter referred to as "EEFL") is provided. It was developed.

The planar light source unit including a plurality of tubular lamps which can be driven in parallel is a lamp for supplying a driving voltage to a printed circuit board (PCB) for wiring and connecting the tubular lamps in parallel. Driving PCBs are installed inside and outside of the case, respectively. These wiring PCBs and lamp driving PCBs are connected by wires. For this reason, not only the structure and work process of the planar light source unit are complicated, but also poor connection occurs frequently. The disadvantages of such a parallel drive lamp type planar light source unit are apparent through the backlight unit of the liquid crystal display as shown in FIG. 1.

The liquid crystal display of FIG. 1 includes a backlight unit 20 for irradiating planar light to the rear surface of the liquid crystal panel 10. The backlight unit 20 includes the reflective sheet 24, the first and second holder PCBs 26A and 26B, and the first and second mold frames 30A and 30B, which are sequentially installed in the bottom case 22. Equipped. Each of the first and second holder PCBs 26A and 26B includes an insulating substrate 27A on which a conductive pattern 27B is formed, and a plurality of holders provided on the insulating substrate 27A to be electrically connected to the conductive pattern 27B. 27C). Each of the holders 27C on the first holder PCB 26A receives and holds one electrode of the parallel-driven tubular lamp (ie, EEFL, 28), and each of the holders 27C on the second holder PCB 26B. Holds-holds the other electrode of the tubular lamp 28 which can be driven in parallel. By means of holders 27C on the first and second holder PCBs 26A and 26B, a plurality of tubular lamps 28 are arranged-fixed inside the bottom case 22 side by side. The first and second mold frames 30A, 30B are installed inside the bottom case 22 to cover the corresponding first and second holder PCBs 26A, 26B.

The backlight unit 20 includes optical sheets 32 and support mains 34 sequentially stacked on the first and second mold frames 30A and 30B. The optical sheets 32 allow the light from the tubular lamp 28 to be irradiated uniformly and vertically to the back side of the liquid crystal panel 10. To this end, the optical sheets 32 include a diffusion sheet and a light collecting sheet. The support main 34 supports the liquid crystal panel 10 and protects the optical sheets 32. For this purpose, the support main 34 has the form of a frame that can accommodate the optical sheets 32.

In addition, the backlight unit 20 includes a lamp driving PCB 36 installed on the bottom of the bottom case 22 and a PCB cover 38 protecting the same. The lamp drive PCB 36 supplies the drive voltage required for the lighting of the tubular lamps 28 to the first and second holder PCBs 26A, 26B via the wire 36A. The wire 36A is disposed from the rear surface of the bottom case 22 via the outer surface and the inner surface of the side wall. The wires 36A are electrically connected to the conductive patterns 27B of the first and second holder PCBs 26A, 26B by screws (not shown), so that the first and second holder PCBs 26A, 26B Is fixed to. The grooves 38A formed on the sidewalls of the PCB cover 38 and the grooves 22A formed on the sidewalls of the bottom case 22 guide the path of the wire 36A. The first and second holder PCBs 26A and 26B are also fixed by a plurality of screws (not shown).

As described above, in the planar light source unit used as the backlight unit of the liquid crystal display device, since the holder PCBs 26A26B are separately provided, the structure and the work process of the planar light source unit are inevitably complicated. In addition, since the wires 36A connecting the lamp drive PCB 36 and the holder PCBs 26A and 26B are disposed in a form over the side wall of the bottom case 22, not only electrical connection defects frequently occur. The work process of the planar light source unit 20 becomes more complicated. The complexity of the structure and the work process and the frequent electrical connection defects in the planar light source unit can be seen in the liquid crystal display device as well. In addition, the liquid crystal display is subject to electromagnetic interference because a large portion of the driving voltage path from the lamp driving PCB 36 to the electrode of the tubular lamp is exposed outside the bottom case 22. For this reason, the image quality of the image displayed by a liquid crystal display device falls.

Accordingly, an object of the present invention is to provide a flat display unit suitable for simplifying the structure and the work process.

Another object of the present invention is to provide a flat display unit suitable for preventing the occurrence of a poor electrical connection.

Another object of the present invention is to provide a liquid crystal display device suitable for simplifying the structure and the work process.

Still another object of the present invention is to provide a liquid crystal display device suitable for preventing occurrence of electrical connection failure.

A planar light source unit according to an embodiment of the present invention for achieving the above object, a plurality of tubular lamps that can be driven in parallel; A bottom case accommodating the lamps; Conductive patterns formed in regions on the bottom gate corresponding to both electrodes of the lamps; A plurality of holders disposed on each of the conductive patterns to fix the lamps electrically connected to the corresponding conductive patterns; A lamp driving circuit which generates a lamp driving voltage to be supplied to the conductive patterns; Connection outlets electrically connected to a corresponding conductive pattern and installed through the bottom case; And connection plugs connected to the lamp driving circuit and inserted into corresponding connection outlets to electrically connect the connection lamps with the lamp driving circuits.

A liquid crystal display according to another exemplary embodiment of the present invention may include a plurality of tubular lamps capable of driving in parallel, a bottom case accommodating the lamps, and conductive patterns formed in regions on the bottom gate corresponding to both electrodes of the lamps. For example, a plurality of holders installed on each of the conductive patterns to electrically connect the lamps to a corresponding conductive pattern, a lamp driving circuit generating a lamp driving voltage to be supplied to the conductive patterns, and a corresponding conductive pattern and Connection plugs connected to the lamp housing and penetrating the bottom case, and connection plugs connected to the lamp driving circuit and inserted into a corresponding connection socket to electrically connect the connection plug to the lamp driving circuit. A backlight unit; And a liquid crystal panel which displays an image by controlling the light transmittance of light from the lamps for each pixel.

In addition to the objects of the present invention as described above, other objects, other advantages and other features of the present invention will become apparent from the detailed description of the preferred embodiment with reference to the accompanying drawings.

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

2 is an exploded perspective view of a liquid crystal display using the planar light source unit as a backlight unit according to an exemplary embodiment of the present invention. FIG. 3 is a plan view illustrating a bottom case 210 in which the tubular lamps 230 capable of parallel driving in FIG. 2 are installed, and FIG. 4 is a view illustrating the bottom case 210 of FIG. 3 taken along line A-A '. It is sectional drawing which shows a cross section. Referring to FIG. 2, the liquid crystal display includes a liquid crystal panel 100 and a top case 110 that are sequentially installed on the backlight unit 200. The liquid crystal panel 100 adjusts the amount of per-pixel transmission of the plane light from the backlight unit 200 to display an image. The top case 110 is installed to surround the edge of the liquid crystal panel 100 and a part of the backlight side surface. The top case 110 protects the liquid crystal panel 110 and the backlight unit 200 from external shocks.

The backlight unit 200 includes a reflection sheet 220 sequentially installed inside the bottom case 210, a plurality of tubular lamps 230 that can be driven in parallel, first and second mold frames 240 and 242, and optical sheets. 250 and a supporter main 260. The bottom case 210 is manufactured to have two holder arrays arranged adjacent to each of the side walls facing each other. Each of the holder arrays provided in the bottom case 210 may include a plurality of holders 216 arranged at regular intervals along the sidewall of the bottom case 210, a conductive pattern 214 electrically connecting the holders 216, And an insulating layer pattern 212 electrically separating the bottom case 210 and the conductive pattern 214. The insulating layer pattern 212 is formed at a constant width at an edge adjacent to the sidewall of the bottom case 210. A conductive pattern 214 in the form of a ladder is formed on the surface of the insulating layer pattern 212 along the sidewall of the bottom case 210. Each of the holders 216 is fixed by soldering or screwing to the corresponding crossbar of the conductive pattern 214. Each of the holders 216 adjacent to one side wall of the bottom case 210 receives and holds one electrode of a corresponding parallel driveable tubular lamp (ie, EEFL) 230 to drive the lamp drive voltage from the conductive pattern 214. (Or signal) is transmitted to one electrode of the corresponding tubular lamp 230. Each of the holders 216 adjacent to the other side wall of the bottom case 210 also receives and holds the other electrode of the corresponding parallel-driven tubular lamp (ie, EEFL) 230 to drive the lamp driving voltage from the conductive pattern 214. (Or signal) is transmitted to the other electrode of the corresponding tubular lamp 230. Since the holder arrays for transmitting and fixing the driving voltage to the electrodes of the plurality of tubular lamps in common are directly installed in the bottom case 210, the backlight unit 200 according to the embodiment of the present invention is different. The structure and work process can be simplified.

In addition, the bottom case 210 further includes connection outlets 218 installed in each of the two holder arrays. Each of the connection outlets 218 is installed on the insulating layer pattern 212 at any one of the holders 216 of the corresponding holder array, as shown in FIG. 3, but with a corresponding conductive pattern 214. Electrically connected. Each of the connection outlets 218 is fixed to be exposed to the bottom of the bottom case 210 through the corresponding insulating layer pattern 212 and the bottom of the bottom case 210, as shown in FIG. 4. Each of the connection outlets 218 may have a molding part 218B that forms a storage space toward an exposed portion of the connection outlet 218 that is exposed to the outside of the bottom case 210 and the molding part 218B from an inner wall surface of the storage space. At least one connection pin (ie, a pair of connection pins) 218A is exposed through the middle portion to the outside.

The reflective sheet 220 is installed on the bottom surface of the bottom case 210 between the holder arrays. The plurality of tubular lamps 230 are fixed on both sides of the pair of holders 216 facing each other included in the holder arrays so as to be positioned above the reflective sheet 220. The reflective sheet 220 reflects light from the tubular lamps toward the liquid crystal panel 100. The reflection sheet 220 increases the light efficiency generated in the tubular lamps 230. Each of the first and second mold frames 240 and 242 is installed in the bottom case 210 to cover the edges of the corresponding holder array and the reflective sheet 220. By these first and second mold frames 240 and 242, the uniformity of luminance at the edge of the liquid crystal panel 100 is improved. These first and second mold frames 240 and 242 are fixed not to flow in the horizontal direction by fixing protrusions 219 formed on the bottom surface of the bottom case 210 adjacent to the holder arrays. The optical sheets 250 disposed on the first and second mold frames 240 and 242 allow the light from the tubular lamps 230 to be uniformly and vertically irradiated to the rear surface of the liquid crystal panel 100. To this end, the optical sheets 250 include a diffusion sheet and a light collecting sheet. The support main 260 supports the liquid crystal panel 100 and protects the optical sheets 250. To this end, the support main 260 has a form of a frame that can accommodate the optical sheets 250.

In addition, the backlight unit 200 includes a lamp driving PCB 270 installed on the bottom of the bottom case 210 and a PCB cover 280 protecting the same. The lamp drive PCB 36 generates a drive voltage necessary for turning on the tubular lamps 230. To this end, the lamp driving PCB 270 includes a lamp driving circuit including an inverter and the like. The driving voltage generated in the lamp driving PCB 270 is commonly supplied to the holders 216 on the conductive pattern 214 via the connection plug 272 and the connection pin 218A of the connection outlet 218. Each of the pair of connection plugs 272 electrically connected to the lamp driving PCB 270 by a lead wire is inserted into a storage space of a corresponding connection outlet 218 exposed to the outside of the bottom case 210 to drive the lamp. The lamp driving voltage (or signal) generated at the PCB 270 is applied to the holders 216 of the corresponding holder array via the connecting pins 218A of the corresponding connection outlets 218 and the corresponding conductive patterns 214. Commonly supplied. Since the lamp driving voltage (or signal) is supplied directly to the holders 216 through the bottom surface of the bottom case 210 by the connection plug 272 and the connection outlet 218, the occurrence of electrical connection failure Can be prevented. In addition, since the path from the lamp driving PCB 270 to the electrode of the tubular lamp 230 is not exposed to the outside of the bottom case 210, electromagnetic interference may be minimized. Accordingly, the image quality of the image displayed on the liquid crystal panel 100 may be improved. The PCB cover 280 is installed on the bottom surface of the bottom case 210 to surround the lamp driving PCB 270 and the connection plug 272. The PCB cover 280 protects the lamp drive PCB 270 and the connection plug 272 from external shocks.

As described above, the planar light source unit according to the present invention has a structure in which holder arrays for fixing and fixing driving voltages to the electrodes of a plurality of tubular lamps are installed directly on the bottom case. Accordingly, the structure and the work process of the planar light source unit according to the exemplary embodiment of the present invention can be simplified, and the structure and the work process of the liquid crystal display device are also simplified.

In addition, since the lamp driving voltage is supplied directly to the holders through the bottom surface of the bottom case by the connection plug and the connection outlet, the occurrence of a poor electrical connection is prevented. In addition, the exposure of the path from the lamp drive PCB to the electrode of the tubular lamp can be minimized to minimize electromagnetic interference. Accordingly, the liquid crystal display may display an image of improved image quality.

As described above, the present invention has been limited to the embodiments shown in the accompanying drawings, which are merely exemplary, and those skilled in the art to which the present invention pertains should have the spirit and scope of the present invention. It will be apparent that various modifications, changes and equivalent other embodiments are possible without departing. Therefore, the spirit and scope of the present invention to be protected should be defined by the appended claims.

Claims (12)

A plurality of tubular lamps capable of driving in parallel; A bottom case accommodating the lamps; Conductive patterns formed in regions on the bottom gate corresponding to both electrodes of the lamps; A plurality of holders disposed on each of the conductive patterns to fix the lamps electrically connected to the corresponding conductive patterns; A lamp driving circuit which generates a lamp driving voltage to be supplied to the conductive patterns; Connection outlets electrically connected to a corresponding conductive pattern and installed through the bottom case; And And connection plugs which are connected to the lamp driving circuit and are inserted into corresponding connection outlets to electrically connect the connection lamps with the lamp driving circuits. The method of claim 1, And a dielectric layer pattern for electrically separating a corresponding conductive pattern from the bottom case. The method of claim 2, And a reflective sheet provided between the lamps and the bottom case. The method of claim 2, And optical sheets installed on top of the lamps to allow light from the lamps to proceed uniformly and vertically in a plane. The method of claim 4, wherein And a mold frame installed in the bottom case to support the optical sheets and surround the holders. The method of claim 5, wherein And a fixing protrusion provided in the bottom case to suppress the flow in the horizontal direction of the mold frames. A plurality of tubular lamps capable of driving in parallel, a bottom case accommodating the lamps, conductive patterns formed in regions on the bottom gate corresponding to electrodes on both sides of the lamps, and conductive formed in each of the conductive patterns to correspond to the lamps. A plurality of holders fixed to be electrically connected to the pattern, a lamp driving circuit for generating a lamp driving voltage to be supplied to the conductive patterns, and connection outlets electrically connected to the corresponding conductive patterns and installed through the bottom case. And a backlight unit connected to the lamp driving circuit and including connection plugs inserted into corresponding connection outlets to electrically connect the connection lamps with the lamp driving circuits. And And a liquid crystal panel which displays an image by controlling the light transmittance of the light from the lamps for each pixel. The method of claim 7, wherein And insulating layer patterns electrically separating a corresponding conductive pattern from the bottom case. The method of claim 8, And a reflective sheet disposed between the lamps and the bottom case. The method of claim 8, And optical sheets installed on top of the lamps to allow light from the lamps to be uniformly and vertically propagated in a plane. The method of claim 10, And mold frames installed in the bottom case to support the optical sheets and surround the holders. The method of claim 11, And a fixing protrusion provided in the bottom case to suppress flow in the horizontal direction of the mold frames.

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