KR101318925B1

KR101318925B1 - Backlight unit for Liquid Crystal Display device

Info

Publication number: KR101318925B1
Application number: KR1020060128627A
Authority: KR
Inventors: 이상대; 김재범; 김재진; 김형동
Original assignee: 엘지디스플레이 주식회사
Priority date: 2006-12-15
Filing date: 2006-12-15
Publication date: 2013-10-29
Also published as: KR20080055366A

Abstract

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having a backlight unit using a light emitting diode as a light source.

A feature of the present invention is to change the conventional structure to configure a light emitting diode unit mounted with only one light emitting diode package on one light emitting diode printed circuit board and a printed circuit board module mounted with and attached to a plurality of light emitting diode units, It is possible to provide a liquid crystal display device that can reduce the weight of the liquid crystal display device and, in the event of a bad light emitting diode package, can selectively repair and replace the minimum light emitting diode package, thereby improving process productivity and reducing costs. .

Description

Backlight unit for liquid crystal display device

1A and 1B are plan views schematically illustrating an arrangement structure of a light emitting diode package constituting a light emitting diode unit according to the related art.

Figure 2 is a plan view schematically showing a light emitting diode package mounted on a large area light emitting diode printed circuit board according to the prior art.

3a to 3d schematically show side views of the light emitting diode unit according to the present invention at different planes, rear surfaces, and viewing angles;

Figure 4 is a plan view schematically showing a printed circuit board module according to an embodiment of the present invention.

5 is a schematic view of a printed circuit board module according to another embodiment of the present invention.

FIG. 6 is a view schematically illustrating a printed circuit board module to which light emitting diode printed circuit boards of various shapes according to the present invention are applied. FIG.

7 is an exploded perspective view of a direct type liquid crystal display device using a light emitting diode according to the present invention as a backlight light source.

100: light emitting diode package 113: electrode pattern

115: electrode pin 120: light emitting diode printed circuit board

130: light emitting diode unit 140: printed circuit board module

141: electrode hole 143: groove

145: electrode pattern 150: reflective sheet

151: through hole 160: intermediate light guide plate

170: optical sheet 180: guide panel

190: cover cover 195: Case Top

Recently, with the development of information technology and mobile communication technology, the development of the display device that can visually display information has been made, and the display device can emit light by the self-emissive display having the light emission characteristics and other external factors. Which are classified as non-luminescent displays.

Examples of the non-light emitting display include a liquid crystal display.

The liquid crystal display device does not have a light emitting element, and thus requires a separate light source.

As a result, a backlight unit having a light source is provided on a rear surface thereof to irradiate light toward the front of the liquid crystal panel, thereby realizing an identifiable image.

As a light source of the backlight unit, a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (LED), and a light emitting diode (LED) are used.

In particular, the light emitting diode emits light due to a potential difference when electrons and holes recombine in a semiconductor p-n junction structure.

These light emitting diodes are gallium nitride (GaN), gallium arsenide (GaAs), gallium phosphide (GaP), gallium-arsenide-phosphorus (GaAs1-xPx), gallium-aluminum-arsenic (Ga1-xAlxAs), indium phosphide (InP) And a compound semiconductor composed of indium-gallium-phosphorus (In1-xGaxP) and the like, and have been widely used as a display light source having low brightness, low voltage, long life, and low cost.

Hereinafter, a light emitting diode unit of a direct type backlight assembly using a light emitting diode according to the prior art as a light source will be described with reference to the accompanying drawings.

1A and 1B are plan views schematically illustrating an arrangement structure of a light emitting diode package constituting a light emitting diode unit according to the prior art, and FIG. 2 schematically illustrates a light emitting diode package mounted on a large area light emitting diode printed circuit board. One floor plan.

As shown, the light emitting diode unit 30 of FIG. 1A has a light emitting diode 11 emitting red (R), green (G), and blue (B) color into a package 10 in a cluster form. A plurality of the packages 10 are mounted on a light emitting diode printed circuit board (MCPCB) 20.

In this case, the light emitting diode printed circuit board 20 is connected to a separate backlight driving circuit (not shown) to apply a signal applied from the backlight driving circuit (not shown) to the plurality of light emitting diode packages 10. do.

Accordingly, the plurality of light emitting diodes 11 arranged on the light emitting diode printed circuit board 20 in the form of a package 10 emits red, green, and blue colors, respectively. White light is realized by uniform mixing of light emitted from each light emitting diode 11.

In addition, in FIG. 1B, a plurality of light emitting diodes 11 emitting red (R), green (G), and blue (B) colors are formed on the light emitting diode printed circuit board 20 in the form of a linear package 10. As shown in FIG. 1A, white light is realized by mixing three colors.

However, as shown in FIGS. 1A and 1B, since a plurality of light emitting diode packages 10 are mounted on the light emitting diode printed circuit board 20 at equal intervals and connected in series, a bad light emitting diode package ( When 10) occurs, there is a disadvantage that it is impossible to replace only the light emitting diode package 10 in which a failure occurs.

For this reason, since the entire LED panel 20 including the LED package 10 in which the defect is generated has to be replaced, most of the defects arranged on the LED panel 20 are not defective. A problem arises in that the light emitting diode package 10 needs to be discarded.

This brings about a problem that the productivity of the process is lowered and the process cost is improved.

2 illustrates a structure in which the light emitting diode package 10 is mounted on a light emitting diode printed circuit board 20 having a larger area than that of FIGS. 1a to 1b.

However, the structure as described above not only increases the weight of the liquid crystal display device, but also causes the use of the expensive LED printed circuit board 20 more than before, resulting in an increase in manufacturing cost.

The present invention is to solve the above problems, the light emitting diode unit and the plurality of light emitting diode unit is mounted and attached to only one light emitting diode package mounted on one light emitting diode printed circuit board by changing the conventional structure By constructing a printed circuit board module, it is possible to reduce the weight of the liquid crystal display and to selectively repair and replace only the defective LED package when a defective LED package is generated, thereby improving process productivity and reducing costs. The purpose.

In order to achieve the above object, the present invention provides a light emitting diode printed circuit board; A light emitting diode unit including only one light emitting diode package mounted on an upper surface of the light emitting diode printed circuit board; A printed circuit board module on which the plurality of light emitting diode units are mounted at equal intervals; A reflection sheet mounted on an upper portion of the plurality of light emitting diode units, the reflection sheet including through holes through which light emitting portions of the plurality of light emitting diode packages pass; An intermediate light guide plate configured to be spaced apart from a predetermined space on the reflective sheet to improve mixing and uniformity of light emitted from the light emitting diode package; A backlight unit configured on the intermediate light guide plate and including a plurality of optical sheets which serve to diffuse light and improve a viewing angle; A liquid crystal panel configured on the backlight unit, the liquid crystal panel including two substrates each having an electric field generating electrode facing up and down and a liquid crystal layer interposed therebetween; A guide panel for fixing the plurality of optical sheets and guiding the liquid crystal panel; The present invention provides a liquid crystal display device including an upper case top and a lower gap cover that supports and fixes the liquid crystal panel and the backlight unit.

The shape of the light emitting diode printed circuit board may be variously designed and applied according to the purpose, and the material may be aluminum-based.

The light emitting diode package is a unit combination including at least one of red (R), green (G), and blue (B) light emitting diodes to realize white light by color mixing. Characterized in that arranged in a linear or cluster form.

The printed circuit board module may be made of a dielectric material such as FR4 and CEM3.

In addition, the upper surface of the printed circuit board module is characterized in that the hole (Hole) or the electrode pattern is formed so that the light emitting diode unit can be attached or mounted.

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

3A to 3D are schematic views illustrating side views of the light emitting diode unit according to the present invention having different planes, rear surfaces, and viewing angles.

As shown, the light emitting diode unit 130 is a light emitting diode package that realizes white light by mixing red (R), green (G), and blue (B) three colors on the upper surface of the aluminum-based light emitting diode printed circuit board 120. (100) is mounted.

Here, an electrode pattern 113 is formed on an upper surface of the light emitting diode printed circuit board 120 and connected to the light emitting diode package 100 to apply an electrical signal from the outside.

In addition, the electrode pattern 113 formed on the upper surface of the light emitting diode printed circuit board 120 to fix and electrically connect the light emitting diode unit 130 configured as described above to a printed circuit board module (not shown). Electrode pins 115 having conductivity are formed on both sides so as to correspond to each other.

That is, the light emitting diode unit 130 having the above-described structure is separated from the conventional structure in which a plurality of light emitting diode packages (10 of FIG. 1) are mounted on one light emitting diode printed circuit board (20 of FIG. 1). One light emitting diode printed circuit board 120 is used per light emitting diode package 100.

4 is a plan view schematically illustrating a printed circuit board module according to an exemplary embodiment of the present invention.

As illustrated, the printed circuit board module 140 has an electrode hole 141 corresponding to the electrode pin 115 of the light emitting diode unit 130 on an upper surface thereof to attach the plurality of light emitting diode units 130 to each other. The electrode pattern 145 which is electrically connected to the electrode pin 115 of the light emitting diode unit 100 is continuously formed in an area except for the region to which the plurality of light emitting diode units 130 are attached. .

Therefore, when power is applied from the outside, the electrical signal is sequentially applied to the light emitting diode package 100 by the structure connected in series as described above.

That is, in the conventional structure, even a failure of a single light emitting diode package (10 in FIG. 1) leads to failure of the light emitting diode unit (30 in FIG. 1) to the entire system, but as described above, the printed circuit board module 140 When the plurality of light emitting diode units 130 are configured in the above, the problem can be solved simply by replacing the light emitting diode units 130 corresponding to the defects.

On the other hand, the printed circuit board module 140 is made of a dielectric such as FR4 or CEM3 commonly used, the light emitting diode printed circuit board constituting a conventional light emitting diode unit (30 of FIG. 1) (20 of FIG. 1). ) Has advantages in weight and price.

Therefore, by configuring the plurality of light emitting diode units 130 in the printed circuit board module 140, it is possible to increase the assembly and replacement efficiency, and at the same time reduce the cost than conventional.

In addition, by forming a myriad of holes (not shown) in the printed circuit board module 140, it is possible to further improve the heat dissipation performance than conventional.

5 is a schematic view of a printed circuit board module according to another exemplary embodiment of the present invention.

As shown, the printed circuit board module 140 has grooves 143 formed on the upper surface of the printed circuit board module 140 at regular intervals so that the plurality of light emitting diode units 130 can be inserted therein.

In addition, the electrode pattern 145 for connecting the plurality of light emitting diode packages 100 in series is formed in the upper surface of the printed circuit board module 140 and the groove 143, when the light emitting diode unit 130 is inserted, The electrode pattern 113 formed on the light emitting diode unit 130 and the electrode pattern 145 formed on the printed circuit board module 140 overlap each other and are electrically connected to each other.

Therefore, by inserting the light emitting diode unit 130 in the groove 143 of the printed circuit board module 140 as described above, rather than stacking the light emitting diode unit 130 on the upper surface of the printed circuit board module 140. It is possible to realize better heat dissipation efficiency, and also to manufacture a thinner module than in the related art.

That is, the printed circuit board module 140 of FIG. 4 has a structure in which the light emitting diode unit 130 is fixed and attached to the upper portion of the printed circuit board module 140 by the electrode pin 115. The light emitting diode unit 130 is inserted into the groove 143 to be fixed.

6 is a view schematically illustrating a printed circuit board module to which light emitting diode printed circuit boards of various shapes according to the present invention are applied.

As shown, the shape of the light emitting diode printed circuit board 120 attached or mounted on the printed circuit board module 140 may be designed and applied in various forms according to the convenience or purpose of the process.

In addition, the electrode pattern (not shown) formed in the printed circuit board module 140 to supply power to the light emitting diode package 100 may vary depending on the structure of the light emitting diode package 100 arranged in a linear or cluster form. It is possible to form and change.

As illustrated, the direct type liquid crystal display device 400 includes a liquid crystal panel 300 and a backlight unit 200 that are stacked up and down, a guide frame 180 having a rectangular frame shape surrounding the edges thereof, and a backlight unit. Covering the rear surface of the (200) while the cover cover coupled to the guide panel 180 and the case top 195 of the rectangular frame shape coupled to the guide panel 180 covering the front edge of the liquid crystal panel 300 Include.

The back of the liquid crystal panel 300 is provided with a backlight unit 200 to supply light, the light emitting diode printed circuit board 120 and the only one light emitting diode package mounted on the inner surface of the gap cover 190 and the white light emitting package A plurality of light emitting diode units 130 including 100 are provided and attached to and mounted on an upper surface of the printed circuit board module 140.

In addition, a plurality of through-holes 151 through which the light emitting part of the light emitting diode package 100 passes may be provided so that the light emitting diode unit 130 and the printed circuit board module 140 except for the light emitting part of the light emitting diode package 100 are provided. And the white or silver reflective sheet 150 covering the inner surface of the gap cover 190, the intermediate light guide plate 160 provided thereon, and a diffuser plate and a reflective polarizing sheet for uniformity of brightness to the upper portion thereof. It is composed of a plurality of optical sheets 170 including a light collecting sheet, a diffusion sheet and the like.

Therefore, in the present invention, each light emitting diode unit 130 is shown in a separate form, so that in the case of failure or breakage of some light emitting diode packages 100, only the corresponding light emitting diode unit 130 needs to be replaced. This can greatly reduce the cost and time of replacement.

The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

As described above, according to the present invention, by configuring a light emitting diode unit in which only one light emitting diode package is mounted on one light emitting diode printed circuit board and a plurality of light emitting diode units are mounted and attached, There is an effect of reducing the weight of the liquid crystal display device.

In addition, by forming a heat dissipation space on the printed circuit board module, it is possible to improve heat dissipation efficiency, and in the event of a bad light emitting diode package, it is possible to selectively repair and replace the minimum light emitting diode package, thereby improving process productivity. To reduce costs.

Claims

A light emitting diode unit including a light emitting diode printed circuit board and a light emitting diode package mounted on the printed circuit board;

And a printed circuit board module having a plurality of light emitting diode units fixed at regular intervals on an upper surface thereof, wherein a plurality of first electrode patterns are formed on both sides of the light emitting diode printed circuit board with respect to the light emitting diode package. A plurality of second electrode patterns corresponding to the plurality of first electrode patterns are formed on an upper surface of the printed circuit board module between the light emitting diode units, and a plurality of second electrode patterns corresponding to the plurality of first electrode patterns are disposed below the plurality of light emitting diode units. A pin, and a plurality of holes are formed in the printed circuit board module corresponding to the ends of the plurality of second electrode patterns, and the pins of the light emitting diode unit are fixed to the holes of the printed circuit board module. LED light distribution device.

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The method of claim 1,

And forming a hole in the printed circuit board module and fixing the first electrode pattern to contact the plurality of second electrode patterns by inserting the light emitting diode unit into the hole.

The method of claim 1,

And a groove formed in the printed circuit board module and fixing the first electrode patterns to contact the plurality of second electrode patterns by inserting the light emitting diode unit into the grooves.

The method according to any one of claims 1 and 4,

And a plurality of light emitting diodes configured in the printed circuit board module are connected in series.

The method of claim 1,

LED light emitting device, characterized in that the shape of the light emitting diode printed circuit board made of a circular or polygonal.

The method of claim 6,

LED light emitting device, characterized in that the material of the light emitting diode printed circuit board is aluminum-based.

Claim 8 was abandoned when the registration fee was paid.

The method of claim 1,

The light emitting diode package is a LED light emitting device, characterized in that for forming a unit combination including at least one of the red, green, blue light emitting diode to implement white light through color mixing.

Claim 9 has been abandoned due to the setting registration fee.

9. The method of claim 8,

LED light emitting device, characterized in that each of the light emitting diodes constituting the LED package is arranged in a linear or cluster form.

The method of claim 1,

LED printed circuit board, characterized in that the material of the printed circuit board module is a dielectric such as FR4, CEM3.

An LED light distribution device including a printed circuit board module having a plurality of light emitting diode units fixed at regular intervals on an upper surface thereof;

A reflection sheet mounted on an upper surface of the LED light distribution device to reflect light;

A backlight unit configured on the LED light distribution device and including an intermediate light guide plate and a plurality of optical sheets to improve the mixing and uniformity of the emitted light;

A liquid crystal panel mounted on the optical sheet and including two substrates facing each other and a liquid crystal layer interposed therebetween;

A guide frame having a rectangular frame shape surrounding the liquid crystal panel;

A top cover case and a bottom cover cover the bottom, which support and fix the liquid crystal panel and the backlight unit, wherein a plurality of first electrode patterns are formed on both sides of the light emitting diode printed circuit board with respect to the light emitting diode package. And a plurality of second electrode patterns corresponding to the plurality of first electrode patterns one-to-one with an upper surface of the printed circuit board module between the light emitting diode units, the light emitting diode unit corresponding to the plurality of first electrode patterns A plurality of pins are formed at a lower portion thereof, and a plurality of holes are formed in the printed circuit board module corresponding to the ends of the plurality of second electrode patterns, and the pins of the light emitting diode unit are inserted into the holes of the printed circuit board module. A liquid crystal display device, characterized in that fixed.

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The method of claim 11,

A hole is formed in the printed circuit board module, and the light emitting diode unit is inserted in the hole to fix the plurality of first electrode patterns to be in contact with the plurality of second electrode patterns.

The method of claim 11,

A groove is formed in the printed circuit board module, and the light emitting diode unit is inserted into the groove to fix the plurality of first electrode patterns to be in contact with the plurality of second electrode patterns.

The method according to any one of claims 11 and 14,

The method of claim 11,

The reflective sheet may include a plurality of through-holes that may pass through the light emitting part of the light emitting diode package to cover all of the light emitting diode unit, the printed circuit board module, and an inner surface of the gap cover except for the light emitting part of the light emitting diode package. A liquid crystal display device.