KR20120075144A - Led package array, back light unit using the same and liquid crystal display device having thereof - Google Patents

Abstract

PURPOSE: An LED package array, a backlight unit using the same, and a liquid crystal display device with the same are provided to reduce driving reliability deterioration. CONSTITUTION: A plurality of LED package arrays(150) generate light. A plurality of first blue LED packages(151a) are made of silicate phosphors. A plurality of second blue LED packages(151b) are made of nitride package phosphors. The first and second LED packages are mounted on a substrate(153).

Description

LED package array, backlight unit using the same, and liquid crystal display device having the same {LED PACKAGE ARRAY, BACK LIGHT UNIT USING THE SAME AND LIQUID CRYSTAL DISPLAY DEVICE HAVING THEREOF}

The present invention relates to a white light emitting device and a white light source module using the same, and in particular, an LED package array, a backlight unit using the same, and a liquid crystal display having the same, which can be usefully used in a backlight unit in a liquid crystal display, and can realize high color reproducibility. Relates to a device.

In general, the white light emitting device is widely used as a backlight of the lighting device or the display device. Such a white light emitting device is widely known as a method using a phosphor and a simple combination of blue, red, and green LEDs manufactured by individual LEDs.

Among these, as a method of manufacturing a white light emitting device using a phosphor, a method of applying a yellow phosphor of YAG (Yitrium Aluminum Garnet) series (hereinafter referred to as "YAG phosphor") on a blue LED chip, Background Art A method of applying red / green phosphor together on a blue LED chip is widely used.

1 is a cross-sectional view showing the structure of a white light emitting device using a conventional YAG phosphor.

As shown in FIG. 1, the conventional white light emitting device 51 includes a first mold frame 10 and a package mold formed to define a molding material filling space while accommodating a part of the lead frame 10 therein. A blue LED chip 14 mounted on one of the lead frames 10a of the lead frame 10 inside the package mold 12, and the lead frame 10 and the blue LED chip. Bonding wire 16 for electrical connection of 14;

Here, the molding material 20 is filled in the package mold 12 to protect the blue LED chip 14 and the bonding wire 16. At this time, the YAG phosphor 18 is included in the molding material 20.

When power is applied through the lead frame 10 and blue light is emitted from the blue LED chip 14, a part of the blue light excites the YAG phosphor 18. At this time, since the YAG phosphor 18 has a characteristic of being excited at 460 nm, which is the peak wavelength of the blue LED chip 14, the YAG phosphor 18 emits light with yellow-green fluorescence.

In this way, the yellow-green fluorescence obtained through the YAG phosphor 18 is synthesized with some other blue light emitted directly from the blue LED chip 14 to finally emit white light.

In addition, another method of implementing a white light emitting device is a method of implementing white by exciting red and green phosphors using a blue LED chip as a light source.

On the other hand, low cost modules are mainly used from direct type to edge type for the purpose of cost competitiveness of modules using LED light sources, and white LEDs are used.

The phosphor applied to the LED package of the backlight of the white LED device is composed of a yellow silicate phosphor, a green silicate phosphor (or using only a yellow silicate phosphor), and a red nitride phosphor. There is a backlight of an LED device that emits white light, which is composed of a backlight of a light emitting LED device, a green nitride phosphor, and a red nitride phosphor.

Here, the silicate phosphor is M ₂ SiO ₅ : Eu ^{2 +} It consists of (M = Ca, Sr, Ba, Zn,-) and consists of Ca, Sr, Ba, Zn, silicon, oxygen, and europium among metals. do.

The silicate phosphor is stable in crystal structure, but metal ions are decomposed by the critical temperature and humidity, causing oxidation.

In addition, although a change in wavelength occurs depending on the constituents of M, and thus the composite phase is easily formed, the reliability is lowered. However, the silicate phosphor has a high LED package efficiency wavelength, and various wavelengths can be realized.

However, the silicate phosphor is structurally of ion oscillation (vibration) is generated in accordance with an increase of a temperature stable, in particular Sr ^{2 +} The more ions are substituted, the less the ionic radius causes defect energy to decrease, resulting in lowered luminescence properties.

Nitride phosphors, on the other hand, are red CaAlSiN 3: Eu ^{2 +.} And green Sr ₂ Si ₅ N ₈ : Eu ²⁺ It has a structure, and the constituent material is made of calcium, silicon, europium, and aluminum.

In the case of the nitride phosphor, since no oxygen element is present, oxidation does not occur easily, structurally, it is difficult to form a single phase, and package efficiency is lower than that of the silicate phosphor.

However, the nitride phosphors have a low stokes shift due to their robust and small crystal size, resulting in high thermal stability.

A conventional LED package array composed of such silicate phosphors or nitride phosphors emitting white light will be described with reference to FIG. 2.

FIG. 2 is a plan view illustrating an LED package array including silicate phosphors in the LED package array according to the related art.

The LED package array 50 according to the related art is installed adjacent to opposite sides of the light guide plate 30, and is composed of a plurality of blue LED packages 51 and a substrate 51 on which they are mounted.

Here, the blue LED package 50 may include a yellow silicate (Yellow Silicate) phosphor, a green silicate (Green Silicate) phosphor (or only a yellow silicate phosphor), or a red nitrite phosphor applied to the entire blue LED package. Or a green nitride phosphor.

However, according to the related art, a backlight of an LED device which is composed of a yellow silicate phosphor and a green silicate phosphor (or using only a yellow silicate phosphor) to emit white light has a high brightness and coordinate variation when driving, resulting in driving reliability problems.

In addition, the backlight of the LED device which is composed of green nitride phosphor and red nitride phosphor and emits white light has a disadvantage that the price of the nitride phosphor is higher than that of the silicate phosphor.

Accordingly, the present invention is to solve the above problems, an object of the present invention is a blue LED package consisting of a yellow silicate phosphor, a green silicate phosphor and a red nitride phosphor, and a blue LED package using a green nitride phosphor and a red nitride phosphor The present invention provides an LED package array, a backlight unit having the same, and a liquid crystal display device having the same, which can be expected to improve reliability and reduce costs by mixing the LED package array.

In order to achieve the above object, the LED package array according to the invention, the first blue LED package consisting of a yellow silicate (Yellow Silicate) phosphor, a green silicate (Green Silicate) phosphor and a red nitride (Red Nitride) phosphor, A second blue LED package consisting of a green nitride phosphor and a red nitride phosphor is mixed.

In order to achieve the above object, the backlight unit to which the LED package array according to the present invention is applied comprises a plurality of first blue LED packages composed of yellow silicate phosphor, green silicate phosphor and red nitride phosphor, and green nitride phosphor and red An LED package array configured by mixing a plurality of second blue LED packages composed of nitride phosphors; A light guide plate positioned at a side of the LED package array and converting light incident from the LED package array into planar light and traveling toward the liquid crystal panel; An optical sheet disposed on the light guide plate; And a reflective sheet disposed on the rear surface of the light guide plate.

In order to achieve the above object, a liquid crystal display device having a backlight unit to which the LED package array according to the present invention is applied, the liquid crystal panel; A plurality of first blue LED packages consisting of a yellow silicate phosphor, a green silicate phosphor and a red nitride phosphor to supply light to the liquid crystal panel, and a plurality of second blue LEDs using the green nitride phosphor and the red nitride phosphor An LED package array in which packages are mixed; A light guide plate positioned at a side of the LED package array and converting light incident from the light source into planar light and traveling toward the liquid crystal panel; A panel guide surrounding a side portion of the light guide plate to support the liquid crystal panel; An optical sheet disposed on the light guide plate; A reflective sheet disposed on a rear surface of the light guide plate; And a lower cover for receiving the light guide plate and the reflective sheet.

According to the LED package array according to the present invention, a backlight unit using the same, and a liquid crystal display having the same, a plurality of first blue LED packages comprising a yellow silicate phosphor, a green silicate phosphor, and a red nitride phosphor, a green nitride phosphor, By constructing a second LED package array by mixing a plurality of second blue LED packages composed of red nitride phosphors, it is possible to improve driving reliability deterioration, which is a disadvantage of silicate phosphors, and to reduce costs for high price, which is a disadvantage of nitride phosphors. have.

1 is a cross-sectional view showing the structure of a white light emitting device using a conventional YAG phosphor.
FIG. 2 is a plan view illustrating an LED package array including silicate phosphors in the LED package array according to the related art.
3 is an exploded perspective view of a liquid crystal display device having a backlight unit to which an LED package array according to the present invention is applied.
Figure 4 is a plan view showing the arrangement of the blue LED package of the LED package array according to an embodiment of the present invention.
FIG. 5 is a state diagram in which an LED package array configured by mixing a plurality of LED packages composed of silicate phosphors and a plurality of blue LED packages composed of nitride package phosphors is disposed on both sides of the light guide plate facing each other; FIG. to be.
FIG. 6 illustrates LED package arrays formed by mixing a plurality of blue LED packages composed of silicate phosphors and a plurality of blue LED packages composed of nitride package phosphors, respectively, on opposite sides of the LGP. Referring to FIG. It is a state diagram.
FIG. 7 illustrates an LED package array configured by mixing a plurality of LED packages composed of silicate phosphors and a plurality of blue LED packages composed of nitride package phosphors on both sides of the light guide plate facing each other, and FIG. On the other side, one LED package array is arranged.
FIG. 8 is a view illustrating an LED package array including a plurality of blue LED packages including only silicate phosphors and an LED package array including a plurality of blue LED packages including nitride phosphors according to another embodiment of the present invention. This is a state diagram arranged in each.
FIG. 9 illustrates an LED package array including a plurality of blue LED packages including silicate phosphors, and LED package arrays including a plurality of blue LED packages including nitride package phosphors facing each other on the light guide plate. It is a state diagram arrange | positioned at both sides, respectively.
FIG. 10 illustrates an LED package array including a plurality of blue LED packages including silicate phosphors, and an LED package array including a plurality of blue LED packages including nitride package phosphors facing each other on the light guide plate according to another embodiment of the present invention. It is placed on the side, and the other side is a state diagram where each of the different LED package array is arranged.
11 is an LED package array consisting of a plurality of blue LED packages consisting of silicate phosphors only, and an LED package array consisting of a plurality of blue LED packages consisting of silicate phosphors and nitride phosphors, and nitride according to another embodiment of the present invention. The LED package array composed of only phosphors and the LED package array composed of a plurality of LED packages composed of silicate phosphors and nitride phosphors are disposed on opposite sides of the LGP.
12 is an LED package array consisting of a plurality of blue LED packages consisting of silicate phosphors only, and an LED package array consisting of a plurality of blue LED packages consisting of silicate phosphors and nitride phosphors, and nitride according to another embodiment of the present invention. The LED package array composed of only phosphors and the LED package array composed of a plurality of LED packages composed of silicate phosphors and nitride phosphors are disposed on opposite sides of the light guide plate.
13 and 14 are the LED package array according to the present invention, in the case of the LED package array consisting of a plurality of blue LED package consisting of silicate phosphor and nitride phosphor, and only the LED package array and nitride phosphor composed only of silicate phosphor This is a graph comparing the change of the color coordinate of the configured LED package array.
15 is an LED package array according to the present invention, the LED package array consisting of a plurality of blue LED package consisting of silicate phosphor and nitride phosphor, and the LED package consisting of only the silicate phosphor and an LED package consisting of nitride phosphor A graph comparing the change in brightness of an array.

Hereinafter, an LED package array according to the present invention, a backlight unit using the same, and a liquid crystal display having the same will be described in detail with reference to the accompanying drawings.

3 is an exploded perspective view of a liquid crystal display device having a backlight unit to which an LED package array according to the present invention is applied.

4 is a plan view showing the arrangement of the LED package of the LED package array according to an embodiment of the present invention.

FIG. 5 illustrates an LED package array configured by mixing a plurality of blue LED packages composed of silicate phosphors and a plurality of blue LED packages composed of nitride package phosphors according to an embodiment of the present invention disposed on opposite sides of the LGP; State diagram.

Liquid crystal display device according to the present invention, as shown in Figures 3 to 5, and the liquid crystal panel 110; A backlight unit 100 for supplying light to the liquid crystal panel 110; A panel guide 140 surrounding and supporting the liquid crystal panel 110 and the backlight unit 100; It is coupled to the panel guide 140, and comprises a lower cover 170, the backlight unit 100 is accommodated, and a top case 180 to cover the front edge of the liquid crystal panel 110.

Here, the liquid crystal panel 110 includes a color filter array substrate 110a and a TFT array substrate 110b and a liquid crystal layer (not shown) interposed therebetween. Although not shown in the drawing, the liquid crystal panel 110 is attached to the front surface of the color filter array substrate 110a and the rear surface of the TFT array substrate 110b so that light passing through the liquid crystal panel 110 is cross polarized. It further comprises a front polarizer (not shown) and a rear polarizer (not shown).

In the liquid crystal panel 110, liquid crystal cells forming a pixel unit are arranged in a matrix form, and the liquid crystal cells form an image by adjusting light transmittance according to image signal information transmitted from the driver driving circuit 113.

Although not shown in the drawing, a plurality of gate lines and a plurality of data lines are formed in a matrix form on the TFT array substrate 110b, and thin film transistors (TFTs) are formed at intersections of the gate lines and the data lines. Is formed. The signal voltage transmitted from the driver driving circuit 113 is applied between the pixel electrode and the common electrode (not shown) of the color filter array substrate 110a to be described later through the thin film transistor, and the liquid crystal between the pixel electrode and the common electrode is The light transmittance is determined according to the signal voltage.

Although not shown in the drawing, the color filter array substrate 110a includes a color filter and a common electrode which are formed by repeating red, green, and blue or cyan, magenta, and yellow colors with a black matrix as a boundary. The common electrode is made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

In addition, one side of the liquid crystal panel 110 includes a driving driver 113 for driving unit pixels formed in the liquid crystal panel, and a flexible printed circuit board having one end connected to the liquid crystal panel (FPCB). ) Is connected.

The backlight unit 100 may include a plurality of LED package arrays 150 for generating light, a light guide plate 130 for providing light generated from the LED package arrays 150 to the front surface of the liquid crystal panel 110, And a reflective sheet 160 which is attached to the rear surface of the light guide plate 130 to reflect the light emitted backward, and is laminated on the front surface of the light guide plate 130 to emit light emitted from the light guide plate 130. It includes a plurality of optical sheets 120 to scatter.

Here, the LED package array 150, as shown in Figure 4, a plurality of first blue LED package 151a consisting of silicate phosphor and a plurality of second blue LED package 151b consisting of nitride package phosphor And a substrate 153 on which they are mounted.

In this case, the plurality of first blue LED packages 151a composed of the silicate phosphors include yellow silicate phosphors, green silicate phosphors, and red nitride phosphors.

In addition, the plurality of second blue LED packages 151b including the nitride phosphors may include a green nitride phosphor and a red nitride phosphor.

As shown in FIG. 5, the plurality of blue LED packages 151a and 151b emit light toward the light incident surface 130a of the light guide plate 130. In addition, the substrate 153 is a flexible printed circuit board having excellent bending, and a circuit (not shown) is formed therein to supply external power to the plurality of blue LED packages 151a and 151b through the circuit.

The plurality of optical sheets 120 are for diffusing and condensing light incident from the light guide plate 130. As illustrated in FIG. 5, the diffusion sheet 121, the prism sheet 123, and the protective sheet 125 are provided. ) Is provided. In some cases, it may be provided with two diffusion sheets and two prism sheets. At this time, the diffusion sheet 121 is composed of a base plate and a bead-shaped coating layer formed on the base plate. The diffusion sheet 121 serves to diffuse the light from the plurality of LED package array 150 to supply to the liquid crystal panel 110. The diffusion sheet 121 may be used by overlapping two or three. In addition, the prism sheet 123 is formed in a triangular prism-shaped prism on the upper surface having a constant arrangement. The prism sheet 123 collects light diffused from the diffusion sheet 121 in a direction perpendicular to the plane of the upper liquid crystal panel 110. Two pieces of the prism sheet 123 are generally used, and the micro prisms formed on each prism sheet 123 form a predetermined angle. Therefore, the light passing through the prism sheet 123 almost passes vertically to provide a uniform luminance distribution. The uppermost protective sheet 125 protects the prism sheet 123 that is weak to scratches.

Meanwhile, the light guide plate 130 extends from a light incident surface (not shown) to which light is incident from the plurality of blue LED packages 151a and 151b and extends from the light receiving surface (not shown) to face the liquid crystal panel 110. A light exit surface (not shown) and a dot pattern (not shown) is formed so that light emitted from the blue LED packages 151a and 151b to the light exit surface (not shown) is advanced to the light exit surface.

Accordingly, the light guide plate 130 is positioned along one side of the plurality of blue LED packages 151a and 151b and is disposed on the rear surface of the liquid crystal panel 110 to be generated in the plurality of blue LED packages 151a and 151b. Guided light is directed to the rear surface of the liquid crystal panel 110. The light guide plate 130 is a plane light along the one side of the light guide plate 130, that is, the light irradiated to the light incident surface (not shown) from the blue LED packages 151a and 151b disposed adjacent to the light incident surface (not shown). In other words, the liquid crystal panel 110 is uniformly transmitted through the light emitting surface. As the material of the light guide plate 130, PMMA (Polymethymethacrylate- late) having high strength and not easily deformed or broken and having good transmittance may be used. Here, the light guide plate 130 may be provided in a wedge having a lower surface inclined and having a flat upper surface, or in a plate type in which both the lower surface and the upper surface are parallel to each other. In the case of a liquid crystal display device applied to a small product such as a notebook PC or a mobile phone, a wedge-shaped light guide plate 130 may be applied, and the LED package array 150 may be provided on a thick sidewall. have.

On the other hand, the panel guide 140 is formed in a rectangular frame surrounding the side portion of the light guide plate 130, it is formed of a plastic material or a metal (metal) material such as PC material. In this case, the panel guide 140 has a liquid crystal panel 110 mounted thereon, and a locking part (not shown) is formed on the entire side of the side to surround the lower backlight unit 100. The upper edge portion of the light guide plate 130 is caught by a locking portion (not shown) of the panel guide 140 in a state where the side surface portion of the light guide plate 130 is wrapped by the panel guide 140. It is securely supported by being impossible. In particular, the panel guide 140 is a structure mainly supporting a liquid crystal panel, but in addition to supporting the liquid crystal panel 110, a function of supporting and fixing the light guide plate 130 and the optical sheet 120. Also do. Meanwhile, the panel guide 140 may be configured to have two straight lines in addition to the rectangular frame surrounding the side part of the light guide plate 130 to fix and support both side parts of the light guide plate 130.

The reflective sheet 160 increases the light efficiency by reflecting a part of the light emitted from the lower portion of the light guide plate 130 to the light exit surface of the backlight unit 100, and adjusts the amount of reflection of the entire incident light to uniform the entire light exit surface It has a luminance distribution.

In addition, the lower cover 170 has a rectangular box shape with an open top, and includes a light guide plate 130, an optical sheet 120, and a reflective sheet 160 covered by the panel guide 140. Components are received.

Accordingly, the lower cover 170 in which the liquid crystal panel 110 and the backlight unit 100 are accommodated is combined with the top case 180 surrounding the upper edge of the liquid crystal panel 110 and the side surface of the panel guide 140. As a result, a liquid crystal display device is achieved.

FIG. 6 illustrates LED package arrays formed by mixing a plurality of blue LED packages composed of silicate phosphors and a plurality of blue LED packages composed of nitride package phosphors, respectively, on opposite sides of the LGP. Referring to FIG. It is a state diagram.

Meanwhile, as shown in FIG. 6, a plurality of first blue LED packages 151a composed of silicate phosphors and a plurality of second blue LED packages 151b composed of nitride package phosphors, and a substrate 153 on which they are mounted The LED package array 150 including the disposed on both sides of the light guide plate 130 facing each other.

In this case, the plurality of first blue LED packages 151a composed of the silicate phosphors include yellow silicate phosphors, green silicate phosphors, and red nitride phosphors.

In addition, the plurality of second blue LED packages 151b including the nitride phosphors may include a green nitride phosphor and a red nitride phosphor.

FIG. 7 illustrates an LED package array configured by mixing a plurality of blue LED packages composed of silicate phosphors and a plurality of blue LED packages composed of nitride package phosphors according to an embodiment of the present invention, disposed on opposite sides of the LGP; On the other side, one LED package array is arranged.

As shown in FIG. 7, a plurality of first blue LED packages 151a composed of silicate phosphors and a plurality of second blue LED packages 151b composed of nitride package phosphors, and a substrate 153 on which they are mounted are included. Arranging two LED package arrays 150 on both sides of the light guide plate 130 facing each other, and a plurality of first blue LED packages 151a formed of the silicate phosphors on the remaining sides except for both sides thereof. Each of the plurality of second blue LED packages 151b including the nitride package phosphor and the LED package array 150 including the substrate 153 mounted thereon is disposed one by one.

Meanwhile, the LED package array arrangement according to another embodiment of the present invention will be described with reference to FIGS. 8 to 10.

FIG. 8 illustrates an LED package array including a plurality of blue LED packages composed of silicate phosphors and an LED package array including a plurality of blue LED packages composed of nitride phosphors facing each other of the light guide plate according to another embodiment of the present invention; It is a state figure arrange | positioned at, respectively.

FIG. 9 illustrates an LED package array composed of a plurality of blue LED packages composed of silicate phosphors, and an LED package array composed of a plurality of blue LED packages composed of nitride phosphors facing each other on the light guide plate according to another embodiment of the present invention. It is a state diagram arrange | positioned at the side surface, respectively.

FIG. 10 illustrates an LED package array including a plurality of blue LED packages composed of silicate phosphors, and an LED package array including a plurality of blue LED packages composed of nitride phosphors facing each other of the light guide plate according to another embodiment of the present invention; On the other side, there is a state in which different LED package arrays are arranged.

According to another embodiment of the present invention, as shown in FIG. 8, the first LED package array 250a including a plurality of first blue LED packages 251a including only silicate phosphors and a substrate 253 on which they are mounted; In addition, the second LED package array 250b is disposed on both side surfaces of the light guide plate 230, each of which includes a plurality of second blue LED packages 251b composed of nitride phosphors and a substrate 253 on which they are mounted.

In this case, the plurality of first blue LED packages 251a including only the silicate phosphors are composed of a yellow silicate phosphor, a green silicate phosphor, and a red nitride phosphor.

In addition, the plurality of second blue LED packages 251 b composed of only the nitride phosphors are composed of a green nitride phosphor and a red nitride phosphor.

Meanwhile, according to another embodiment of the present invention, as shown in FIG. 9, the first LED package array 250a including a plurality of first blue LED packages 251a composed only of silicate phosphors and a substrate 253 on which they are mounted. And a plurality of second blue LED packages 251b composed of only nitride phosphors and a substrate 253 on which the second LED package array 250b is formed as a group, and the light guide plate facing each other is formed as a group. It may be disposed on both sides of the 230.

According to another embodiment of the present invention, as shown in FIG. 10, the first LED package array 250a including a plurality of first blue LED packages 251a composed only of silicate phosphors and a substrate 253 on which they are mounted. And a plurality of second blue LED packages 251b composed of only nitride phosphors and a substrate 253 on which the second LED package array 250b is formed as a group, and the light guide plate facing each other is formed as a group. The first LED package array 250a and the second blue LED package 251b may be disposed on both side surfaces of the 230 and the remaining side surfaces of the light guide plate 230, respectively.

On the other hand, the LED package array arrangement according to another embodiment of the present invention will be described with reference to Figures 11 and 12 as follows.

11 is an LED package array consisting of a plurality of LED packages consisting of silicate phosphors only, and an LED package array consisting of a plurality of LED packages composed of silicate phosphors and nitride phosphors, and nitride nitrides according to another embodiment of the present invention. The LED package array composed of the LED package array and the LED package array composed of the plurality of LED packages composed of the silicate phosphor and the nitride phosphor are disposed on opposite sides of the LGP.

12 is an LED package array consisting of a plurality of blue LED packages consisting of silicate phosphors only, and an LED package array consisting of a plurality of blue LED packages consisting of silicate phosphors and nitride phosphors, and nitride according to another embodiment of the present invention. The LED package array composed of only phosphors and the LED package array composed of a plurality of LED packages composed of silicate phosphors and nitride phosphors are disposed on opposite sides of the light guide plate.

According to another embodiment of the present invention, as shown in FIG. 11, the first LED package array 350a including a plurality of first blue LED packages 351a composed only of silicate phosphors and a substrate 253 on which they are mounted. And a second LED package array 350c including a plurality of first LED packages 351a composed of silicate phosphors, a plurality of second blue LED packages 351b composed of nitride phosphors, and a substrate 253 on which they are mounted. Let it be a 1st group.

In addition, a plurality of second blue LED packages 351b composed of only nitride phosphors, a second LED package array 350b composed of a substrate 253 mounted thereon, and a plurality of first blue LED packages 351a composed of silicate phosphors ) And a second LED package array 350c composed of a plurality of second blue LED packages 351b formed of a nitride phosphor and a substrate 253 on which they are mounted as a second group.

Accordingly, the first group and the second group may be disposed on opposite side surfaces of the light guide plate 330, respectively.

Meanwhile, as shown in FIG. 12, the first group and the second group are disposed on opposite sides of the light guide plate 330, respectively, and a plurality of silicate phosphors are formed on the remaining opposite sides of the light guide plate 330. A first LED package array 350a including two first blue LED packages 351a and a substrate 253 on which they are mounted, a plurality of second LED packages 351b including only nitride phosphors, and a substrate 253 on which they are mounted. Each of the second LED package array 350b may be disposed.

13 and 14 are the LED package array according to the present invention, in the case of the LED package array consisting of a plurality of blue LED package consisting of silicate phosphor and nitride phosphor, and only the LED package array and nitride phosphor composed only of silicate phosphor This is a graph comparing the change of the color coordinate of the configured LED package array.

15 is an LED package array according to the present invention, the LED package array consisting of a plurality of blue LED package consisting of silicate phosphor and nitride phosphor, and the LED package consisting of only the silicate phosphor and an LED package consisting of nitride phosphor A graph comparing the change in brightness of an array.

As shown in FIGS. 13 to 15, compared to a backlight unit employing an LED package array composed of conventional silicate phosphors, a backlight unit employing a hybrid phosphor, that is, an LED package array composed of silicate phosphor and nitride phosphor In this case, it can be seen that color coordinates and luminance fluctuations are small according to the driving time.

As described above, according to the LED package array according to the present invention, a backlight unit using the same, and a liquid crystal display having the same, a blue LED package using a yellow silicate phosphor, a green silicate phosphor, and a red nitride phosphor, and a green nitride phosphor By combining the LED package array with a blue LED package using a red nitride phosphor, it is possible to improve the driving reliability degradation, which is a disadvantage of the silicate phosphor, and to reduce the cost for the high price, which is a disadvantage of the nitride phosphor.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that.

Therefore, since the embodiments described above are provided to completely inform the scope of the invention to those skilled in the art to which the present invention pertains, it should be understood that they are exemplary in all respects and not limited. The invention is only defined by the scope of the claims.

100: backlight unit 110: liquid crystal panel
110a: color filter array substrate 110b: TFT array substrate
113: drive driver 115: printed circuit board
120: optical sheet 121: diffusion sheet
123: prism sheet 125: protective sheet
130: light guide plate 140: panel guide 150: LED package array 151: blue LED package 151a: silicate phosphor blue LED package
151a: nitride phosphor blue LED package
153: substrate 160: reflective sheet 163: opening 170: bottom cover

Claims (6)

First blue LED package consisting of yellow silicate phosphor, green silicate phosphor, and red nitride phosphor; second blue LED package consisting of green nitride phosphor and red nitride phosphor Package array for a backlight unit consisting of a mixture of these. The LED package array of claim 1, wherein the first blue LED package and the second blue LED package are alternately arranged alternately. An LED package array consisting of a mixture of a plurality of first blue LED packages consisting of yellow silicate phosphors, green silicate phosphors and red nitride phosphors, and a plurality of second blue LED packages consisting of green nitride phosphors and red nitride phosphors; ;
A light guide plate positioned at a side of the LED package array and converting light incident from the LED package array into planar light and traveling toward the liquid crystal panel;
An optical sheet disposed on the light guide plate; And
And a backlight unit to which an LED package array including a reflection sheet disposed on a rear surface of the light guide plate is applied. 4. The LED package array of claim 3, wherein the plurality of first blue LED packages and the plurality of second blue LED packages are mixed with each other on opposite sides of the light guide plate, or face each other. The backlight unit to which the LED package array is applied, characterized in that arranged on each side of the two or each of the four sides. A liquid crystal panel;
A plurality of first blue LED packages consisting of a yellow silicate phosphor, a green silicate phosphor and a red nitride phosphor to supply light to the liquid crystal panel, and a plurality of second blue LEDs using the green nitride phosphor and the red nitride phosphor An LED package array in which packages are mixed;
A light guide plate positioned at a side of the LED package array and converting light incident from the light source into planar light and traveling toward the liquid crystal panel;
A panel guide surrounding a side portion of the light guide plate to support the liquid crystal panel;
An optical sheet disposed on the light guide plate;
A reflective sheet disposed on a rear surface of the light guide plate; And
And a backlight unit configured to include a lower cover to accommodate the light guide plate and the reflective sheet. The LED package array of claim 5, wherein the plurality of first blue LED packages and the plurality of second blue LED packages are mixed with each other, respectively, disposed on opposite sides of the light guide plate or facing each other on the light guide plate. The backlight unit to which the LED package array is applied, characterized in that arranged on each side of the two or each of the four sides.

Images