CN101476703B

CN101476703B - Backlight unit

Info

Publication number: CN101476703B
Application number: CN2008101829401A
Authority: CN
Inventors: 权五详; 李象大; 姜文植
Original assignee: LG Display Co Ltd
Current assignee: LG Display Co Ltd
Priority date: 2007-12-31
Filing date: 2008-12-05
Publication date: 2011-02-16
Anticipated expiration: 2028-12-05
Also published as: KR20090073965A; CN102032515A; CN101476703A; KR101469476B1

Abstract

A backlight unit capable of preventing a degradation in luminance, while achieving a reduction in heat generation and a reduction in manufacturing costs by adjusting the arrangement of the light sources while reducing the number of the light sources is disclosed. The disclosed backlight unit includes a bottom cover formed with a plurality of light source groups each including a plurality of light sources arranged in one direction. The spacing of the adjacent light source groups increases gradually from a central portion of the bottom cover to opposite edges of the bottom cover.

Description

Back light unit

The application requires the korean patent application No.10-2007-0141547 of submission on December 31st, 2007, and the priority of the korean patent application No.10-2008-0053576 of submission on June 9th, 2008, here it is incorporated among the application as a reference, just as what here list fully.

Technical field

The present invention relates to a kind of back light unit, thereby relate in particular to a kind of back light unit that can use the light source minimizing production cost of decreased number.

Background technology

Display device can be categorized as can self luminous emission display device, such as cathode-ray tube, and organic electroluminescent display device, plasma display equipment (PDP); And self can not produce light and the non-emission display device of the independent light source of needs, such as liquid crystal display (LCD) equipment.

General LCD equipment comprises two display floaters that are provided with the electric field generating electrodes, and the liquid crystal panel between display floater.Liquid crystal layer has dielectric anisotropy.In LCD equipment, when applying voltage for the electric field generating electrodes, produce electric field at liquid crystal layer.Electric-field intensity is adjusted with voltage change.According to the adjustment of electric-field intensity, controlled by the light transmission of liquid crystal layer.Therefore, obtain desired images.Light can be the light that is produced by the independent artificial light sources that is configured on the LCD equipment, or can be natural daylight.

For the light source of LCD equipment, typically use several lamps.Especially,, use fluorescent lamp for the light source that light can be provided equably for whole liquid crystal panel of the rear surface that is positioned at liquid crystal panel, such as external electrode fluorescence lamp (EEFL), or cold-cathode fluorescence lamp (CCFL), or light emitting diode (LED).

The LED-backlit unit of the current LCD equipment of actively researching and developing, its advantage par excellence is the best colour vision that it can provide the user to expect.

Yet the LED that is used for the light source of back light unit can show the unexpected variation of the optical efficiency that causes because of being heated.For example, LED is the internal heat resource of response external environment or LCD equipment sensitively, makes LED can lose color balance.

Especially, the problems referred to above are more serious in the back light unit that is applied to large-scale LCD equipment, because back light unit uses a large amount of LED.In addition, since the increase of LED number, the problem that exists production cost to increase.

Summary of the invention

Therefore, the present invention aims to provide a kind of back light unit, and it can overcome the one or more problems that caused by above-mentioned restriction of the prior art or shortcoming substantially.

The purpose of this invention is to provide a kind of back light unit, it can be by adjusting the layout of light source under the situation that will lack number of light sources, and realization is used for the raising of the stability of light source of back light unit, the minimizing that heat produces, and the reduction of production cost.

About other advantage, purpose and feature of the present invention, a part will be illustrated in the specification hereinafter, and a part will hereinafter become apparent by studying for one skilled in the art, perhaps can figure out from practice of the present invention.Can realize and obtain purpose of the present invention and other advantage by the structure that particularly points out in printed instructions and claim and the accompanying drawing.

In order to realize these purposes and other advantage, according to the intent of the present invention, as specializing here with broadly described, back light unit comprises: the bottom that is formed with a plurality of light source groups, each light source group comprises a plurality of light sources of arranging in one direction, wherein have spacing between the adjacent light source group in described a plurality of light source groups, this spacing increases to the relative two edges of described bottom gradually from the core of described bottom.

According to another kind of embodiment, the invention provides a kind of back light unit, comprise: the bottom that is formed with a plurality of light source groups, each described light source group comprises a plurality of light sources of arranging in one direction, has spacing between the adjacent light source group in wherein said a plurality of light source group, this spacing increases to the relative two edges of described bottom gradually from the core of described bottom, reduces gradually then.

According to another embodiment, the invention provides a kind of back light unit, comprise: the bottom that is formed with a plurality of light source groups, each described light source group comprises a plurality of light sources of arranging in one direction, wherein has spacing between the adjacent light source in the light source that comprises of each described light source group, this spacing increases to the relative two edges of described bottom gradually from the core of described bottom, reduces gradually then.

Back light unit according to the present invention has following effect.

The first, can reduce number of light sources, thereby realize that the heat that produces from light source reduces and production cost reduces.

The second, because the spacing between the adjacent light source group increases to the relative two edges of bottom gradually from the core of bottom, so can reduce the number of the light source that each light source group comprises.

The 3rd, can pass through the spacing of the edge of increase bottom, arrange light source thick and fast towards the core of bottom, thereby realize that low current drives operation and power consumption minimizing.

The generality that should be appreciated that front of the present invention is described and following detailed all is exemplary with indicative, is intended to provide the present invention to claimed further to explain.

Description of drawings

Accompanying drawing is in conjunction with a part that constitutes the application in this application, in order to provide further understanding of the present invention.The accompanying drawing illustration embodiments of the present invention and with specification in order to explain principle of the present invention.In the accompanying drawings:

Fig. 1 is an illustration according to the view of the back light unit of first embodiment of the invention;

Fig. 2 is an illustration according to the view of the back light unit of second embodiment of the invention;

Fig. 3 is an illustration according to the view of the back light unit of third embodiment of the invention;

Fig. 4 is an illustration according to the view of the back light unit of four embodiment of the invention;

Fig. 5 is an illustration according to the view of the back light unit of fifth embodiment of the invention;

Fig. 6 is an illustration according to the view of the back light unit of sixth embodiment of the invention;

Fig. 7 is an illustration according to the view of the back light unit of seventh embodiment of the invention;

Fig. 8 is an illustration according to the view of the back light unit of eighth embodiment of the invention;

Fig. 9 is an illustration according to the view of the back light unit of ninth embodiment of the invention;

Figure 10 is an illustration according to the view of the back light unit of tenth embodiment of the invention;

Figure 11 is an illustration according to the view of the back light unit of eleventh embodiment of the invention;

Figure 12 is an illustration according to the view of the back light unit of twelveth embodiment of the invention;

Figure 13 is an illustration according to the view of the back light unit of thirteenth embodiment of the invention;

Figure 14 is an illustration according to the view of the back light unit of fourteenth embodiment of the invention;

Figure 15 is an illustration according to the view of the back light unit of fifteenth embodiment of the invention;

Figure 16 is for describing the chart of the spacing between the adjacent light source in each light source group shown in Figure 15;

Figure 17 comprises respectively the chart of the comparing result of the back light unit of the light source of layout differently for showing;

The chart of the brightness of the light that Figure 18 sends for the liquid crystal panel of describing A, B, C and the D type back light unit use Figure 17 respectively;

Figure 19 is that illustration is equipped with the view according to the LCD equipment of the back light unit of sixteenth embodiment of the invention; And

Figure 20 to 22 has illustrated the view of adjusting the method for light source position.

The specific embodiment

Describe preferred implementation of the present invention in detail in conjunction with back light unit now, the example is shown in the drawings.

First embodiment

Fig. 1 is an illustration according to the view of the back light unit of first embodiment of the invention.

As shown in Figure 1, comprise the bottom 310 that is formed with a plurality of light source group LG1 to LG12 according to the back light unit of first embodiment of the invention, each light source group LG1 to LG12 comprises a plurality of light source L that arrange in one direction.Spacing among the light source group LG1 to LG12 between the adjacent light source group increases to the relative two edges of bottom 310 gradually from the core of bottom 310.

The light source L of each light source group LG1 to LG12 aims at along the length direction of the minor face of bottom 310, promptly aims on Y direction.Light source group LG1 to LG12 with above-mentioned layout arranges along the length direction on the long limit of bottom 310, promptly arranges on X-direction.

As shown in Figure 1, among the included a plurality of light source L of each light source group LG1 to LG12, has identical spacing dy between the adjacent light source L.

Light source group LG1 to LG12 comprises the light source L of similar number.The included light source L of each light source group LG1 to LG12 is corresponding one by one with the light source L of all the other light source groups.The corresponding light source L of light source group LG1 to LG12 aims on X-direction.

Spacing between the corresponding light source L that adjacent light source group comprises respectively among the light source group LG1 to LG12 increases to the relative two edges of bottom 310 gradually from the core of bottom 310.

Below will make a more detailed description this.

Light source group LG1 to LG12 can be divided into the central light source group that is arranged in bottom 310 cores, be arranged in a plurality of first peripheral light source group between the edge of central light source group and bottom 310, and be arranged in a plurality of second peripheral light source group between another edge of central light source group and bottom 310.

The central light source group comprises and being arranged as from two nearest light source groups of the core of bottom 310.In other words, the central light source group comprises and being arranged as from the nearest first light source group LG1 of a side of the core of bottom 310 with from the nearest secondary light source group LG2 of opposite side of the core of bottom 310.

The first peripheral light source group comprises the left side that is arranged in the first light source group LG1 and the 3rd to the 7th light source group LG3 to LG7 between bottom 310 left hand edges.On the other hand, the second peripheral light source group comprises the right side that is arranged in secondary light source group LG2 and the 8th to the 12 light source group LG8 to LG12 between bottom 310 right hand edges.

Spacing between the adjacent light group in the central light source group and the first peripheral light source group increases to an edge of bottom 310 gradually from the core of bottom 310.Equally, the spacing between the adjacent light source group in the central light source group and the second peripheral light source group increases to another edge of bottom 310 gradually from the core of bottom 310.

In other words, the spacing between the adjacent light source group increases to an edge of bottom 310 gradually from the core of bottom 310 among the first, the 3rd, the 4th, the 5th, the 6th and the 7th light source group LG1, LG3, LG4, LG5, LG6 and the LG7.The second, the spacing between the adjacent light source group increases to another edge of bottom 310 gradually from the core of bottom 310 among the 8th, the 9th, the tenth, the 11 and the 12 light source group LG2, LG8, LG9, LG10, LG11 and the LG12.

For example, as shown in Figure 1, spacing between the first and the 3rd light source group LG1 and the LG3 i.e. the first spacing dx1, spacing between the third and fourth light source group LG3 and the LG4 i.e. the second spacing dx2, spacing between the 4th and the 5th light source group LG4 and the LG5 i.e. the 3rd spacing dx3, spacing between the 5th and the 6th light source group LG5 and the LG6 i.e. the 4th spacing dx4, and i.e. the 5th spacing dx5 of the spacing between the 6th and the 7th light source group LG6 and the LG7, and they differ from one another.Particularly, the first spacing dx1 minimum between nearest first light source group LG1 of the core of bottom 310 and the three light source group LG3 adjacent with the first light source group LG1, from the core of bottom 310 farthest the 7th light source group LG7 and the 5th spacing dx5 maximum between the 6th light source group LG6 adjacent with the 7th light source group LG7.In other words, the second spacing dx2 is bigger than the first spacing dx1, and the 3rd spacing dx3 is bigger than the second spacing dx2, and the 4th spacing dx4 is bigger than the 3rd spacing dx3, and the 5th spacing dx5 is bigger than the 4th spacing dx4.

Similarly, spacing between the second and the 8th light source group LG2 and the LG8 i.e. the 6th spacing dx6, spacing between the 8th and the 9th light source group LG8 and the LG9 i.e. the 7th spacing dx7, spacing between the 9th and the tenth light source group LG9 and the LG10 i.e. the 8th spacing dx8, spacing between the tenth and the 11 light source group LG10 and the LG11 i.e. the 9th spacing dx9, spacing between the 11 and the 12 light source group LG11 and the LG12 i.e. ten pitch dx6, and they differ from one another.Particularly, the 6th spacing dx6 minimum between nearest secondary light source group LG2 of the core of bottom 310 and the eight light source group LG8 adjacent with secondary light source group LG2, from the core of bottom 310 farthest the 12 light source group LG12 and the ten pitch dx10 maximum between the 11 light source group LG11 adjacent with the 12 light source group LG12.In other words, the 7th spacing dx7 is bigger than the 6th spacing dx6, and the 8th spacing dx8 is bigger than the 7th spacing dx7, and the 9th spacing dx9 is bigger than the 8th spacing dx8, and ten pitch dx10 is bigger than the 9th spacing dx9.

The first and the 6th spacing dx1 and dx6 equate that the second and the 7th spacing dx2 and dx7 equate that the 3rd and the 8th spacing dx3 and dx8 equate that the 4th and the 9th spacing dx4 and dx9 equate, and the 5th is equal with dx10 with ten pitch dx5.

Certainly, the first and the 6th spacing dx1 and dx6 can be set to differ from one another, the second and the 7th spacing dx2 and dx7 can be set to differ from one another, the the 3rd and the 8th spacing dx3 and dx8 can be set to differ from one another, the the 4th and the 9th spacing dx4 and dx9 can be set to differ from one another, the 5th and ten pitch dx5 and dx10 can be set to differ from one another.

These spacings can increase with predetermined increment rate.

For example, the second spacing dx2 can be than the big 0.2mm of the first spacing dx1.The 3rd spacing dx3 can be than the big 0.2mm of the second spacing dx2.The 4th spacing dx4 can be than the big 0.2mm of the 3rd spacing dx3.The 5th spacing dx5 can be than the big 0.2mm of the 4th spacing dx4.The the 6th to ten pitch dx6 to dx10 can increase by the increment rate identical with above-mentioned increment rate.

Simultaneously, the spacing between the first and second light source group LG1 and the LG2 can equate with the spacing between the first and the 3rd light source group LG1 and the LG3.

Above-mentioned spacing is represented the spacing between the adjacent Different Light group light source L that comprise, in correspondence with each other.For example, the first spacing dx1 represent light source L1 that the first light source group LG1 is included and secondary light source group LG2 included and the corresponding light source L2 of light source L1 between spacing.

Second embodiment

Fig. 2 is an illustration according to the view of the back light unit of second embodiment of the invention.

As shown in Figure 2, comprise light source group LG1 to LG8 according to the back light unit of second embodiment of the invention, each light source group all comprises a plurality of light source L that the length direction (being X-direction) along the long limit of bottom 310 is aimed at.Light source group LG1 to LG8 with above-mentioned layout arranges along the length direction (being Y direction) of the minor face of bottom 310.

As shown in Figure 2, among the included light source L of each light source group LG1 to LG8, has identical spacing dx between the adjacent light source L.

Light source group LG1 to LG8 comprises the light source L of similar number.The included light source L of each light source group LG1 to LG8 is corresponding one by one with the light source L of all the other light source groups.The corresponding light source L of light source group LG1 to LG8 aims on Y direction.

Spacing between the corresponding light source L that adjacent light source group comprises respectively among the light source group LG1 to LG8 increases to the relative two edges of bottom 310 gradually from the core of bottom 310.

Below will make a more detailed description this.

Light source group LG1 to LG8 can be divided into the central light source group that is arranged in bottom 310 cores, be arranged in a plurality of first peripheral light source group between the edge of central light source group and bottom 310, and be arranged in a plurality of second peripheral light source group between another edge of central light source group and bottom 310.

The first peripheral light source group comprises the 3rd to the 5th light source group LG3 to LG5 between the top edge of the upside that is arranged in the first light source group LG1 and bottom 310.On the other hand, the second peripheral light source group comprises the 6th to the 8th light source group LG6 to LG8 between the lower limb of the downside that is arranged in secondary light source group LG2 and bottom 310.

Spacing in the central light source group and the first peripheral light source group between the adjacent light source group increases to the top edge of bottom 310 gradually from the core of bottom 310.Equally, the spacing between the adjacent light source group increases to the lower limb of bottom 310 gradually from the core of bottom 310 in the central light source group and the second peripheral light source group.

In other words, the spacing between the adjacent light source group increases to the top edge of bottom 310 gradually from the core of bottom 310 among the first, the 3rd, the 4th and the 5th light source group LG1, LG3, LG4 and the LG5.The second, the spacing between the adjacent light source group increases to the lower limb of bottom 310 gradually from the core of bottom 310 among the 6th, the 7th and the 8th light source group LG2, LG6, LG7 and the LG8.

For example, as shown in Figure 2, the spacing between the first and the 3rd light source group LG1 and the LG3 i.e. the first spacing dy1, and the spacing between the third and fourth light source group LG3 and the LG4 i.e. the second spacing dy2, spacing between the 4th and the 5th light source group LG4 and the LG5 i.e. the 3rd spacing dy3, and they differ from one another.Particularly, the first spacing dy1 minimum between nearest first light source group LG1 of the core of bottom 310 and the three light source group LG3 adjacent with the first light source group LG1, from the core of bottom 310 farthest the 5th light source group LG5 and the 3rd spacing dy3 maximum between the 4th light source group LG4 adjacent with the 5th light source group LG5.In other words, the second spacing dy2 is bigger than the first spacing dY1, and the 3rd spacing dy3 is bigger than the second spacing dy2.

Similarly, spacing between the second and the 6th light source group LG2 and the LG6 i.e. the 4th spacing dy4, spacing between the 6th and the 7th light source group LG6 and the LG7 i.e. the 5th spacing dy5, and the spacing between the 7th and the 8th light source group LG7 and the LG8 i.e. the 6th spacing dy6, and they differ from one another.Particularly, the 4th spacing dy4 minimum between nearest secondary light source group LG2 of the core of bottom 310 and the six light source group LG6 adjacent with secondary light source group LG2, from the core of bottom 310 farthest the 8th light source group LG8 and the 6th spacing dy6 maximum between the 7th light source group LG7 adjacent with the 8th light source group LG8.In other words, the 5th spacing dy5 is bigger than the 4th spacing dy4, and the 6th spacing dy6 is bigger than the 5th spacing dy5.

The first and the 4th spacing dy1 and dy4 equate that the second and the 5th spacing dy2 and dy5 equate, and the 3rd and the 6th spacing dy3 is equal with dy6.

Certainly, the first and the 4th spacing dy1 and dy4 can be set to differ from one another, and the second and the 5th spacing dy2 and dy5 can be set to differ from one another, and the 3rd and the 6th spacing dy3 and dy6 can be set to differ from one another.

These spacings can increase by predetermined increment rate.

For example, the second spacing dy2 can be than the big 0.2mm of the first spacing dy1.The 3rd spacing dy3 can be than the big 0.2mm of the second spacing dy2.The the 4th to the 6th spacing dy4 to dy6 can increase by the increment rate identical with above-mentioned increment rate.

Above-mentioned spacing is represented the spacing between the adjacent Different Light group light source L that comprise, in correspondence with each other.For example, the first spacing dy1 represent light source L1 that the first light source group LG1 is included and secondary light source group LG2 included and the corresponding light source L2 of light source L1 between spacing.

The 3rd embodiment

Fig. 3 is an illustration according to the view of the back light unit of third embodiment of the invention.

As shown in Figure 3, comprise the bottom 310 that is formed with a plurality of light source group LG1 to LG12 according to the back light unit of third embodiment of the invention, each light source group all comprises a plurality of light source L that arrange in one direction.Spacing among the light source group LG1 to LG12 between the adjacent light source group increases to the relative two edges of bottom 310 gradually from the core of bottom 310.

Light source L among each light source group LG1 to LG12 aims at along the length direction (being Y direction) of the minor face of bottom 310.Light source group LG1 to LG12 with above-mentioned layout arranges along the length direction (being X-direction) on the long limit of bottom 310.

Spacing between the corresponding light source L that adjacent light source group comprises respectively among the light source group LG1 to LG12 increases to the relative two edges of bottom 310 gradually from the core of bottom 310.From the explanation of first embodiment, obtain the details of this layout with may be obvious that.

Simultaneously, the spacing between the adjacent light source L increases to the relative two edges of bottom 310 gradually from the core of bottom 310 among the included a plurality of light source L of each light source group LG1 to LG8.

Work as hypothesis, for example the first light source group LG1 comprises first to the 8th light source L1 to L8, spacing between the first and the 3rd light source L1 and the L3 i.e. the first spacing dy1, spacing between the third and fourth light source L3 and the L4 i.e. the second spacing dy2, the spacing that reaches between the 4th and the 5th light source L4 and the L5 is the 3rd spacing dy3, and they differ from one another.Particularly, in the first spacing dy1 minimum of a direction between nearest first light source L1 of the core of the first light source group LG1 and the secondary light source L2 adjacent with the first light source L1, a direction from the core of the first light source group LG1 farthest the 5th light source L5 and the 3rd spacing dy3 maximum between the 4th light source L4 adjacent with the 5th light source L5.In other words, the second spacing dy2 is bigger than the first spacing dy1, and the 3rd spacing dy3 is bigger than the second spacing dy2.

Similarly, the spacing between the second and the 6th light source L2 and the L6 i.e. the 4th spacing dy4, and the spacing between the 6th and the 7th light source L6 and the L7 i.e. the 5th spacing dy5, and the spacing that reaches between the 7th and the 8th light source L7 and the L8 is the 6th spacing dy6, and they differ from one another.Particularly, in the four spacing dy4 minimum of other direction between nearest secondary light source L2 of the core of the first light source group LG1 and the six light source L6 adjacent with secondary light source L2, other direction from the core of the first light source group LG1 farthest the 8th light source L8 and the 6th spacing dy6 maximum between the 7th light source L7 adjacent with the 8th light source L8.In other words, the 5th spacing dy5 is bigger than the 4th spacing dy4, and the 6th spacing dy6 is bigger than the 5th spacing dy5.

The first and the 4th spacing dy1 and dy4 equate that the second and the 5th spacing dy2 and dy5 equate that the 3rd and the 6th spacing dy3 and dy6 equate.

The increment rate of the spacing between the adjacent Different Light group light source L that comprise, in correspondence with each other, and the increment rate of the spacing between the adjacent light source L that comprises of each light source group can equate or different.

For example, the increment rate of the spacing between the light source L in correspondence with each other that adjacent as mentioned above Different Light group comprises is 0.2mm, and the increment rate of the spacing between the adjacent light source L that each light source group comprises can be 0.2mm or other values.

The 4th embodiment

Fig. 4 is an illustration according to the view of the back light unit of four embodiment of the invention.

Back light unit according to four embodiment of the invention is similar with first embodiment shown in Figure 1.Yet, comprise an independent light source group according to the central light source group in the back light unit of four embodiment of the invention, and this independent light source group, promptly the first light source group LG1 arranges along the center line that bottom 310 is divided into left and right sides two halves.

All the other structure and first embodiment the same.Therefore, from the explanation of first embodiment, obtain the details of all the other structures with may be obvious that.

The 5th embodiment

Fig. 5 is an illustration according to the view of the back light unit of fifth embodiment of the invention.

Back light unit according to fifth embodiment of the invention is similar with second embodiment shown in Figure 2.Yet, comprising an independent light source group according to the central light source group in the back light unit of fifth embodiment of the invention, and this independent light source group, i.e. the first light source group LG1 arranges along bottom 310 being divided into up and down the center line of two halves.

All the other structure and second embodiment the same.

Therefore, from the explanation of second embodiment, obtain the details of all the other structures with may be obvious that.

The 6th embodiment

Fig. 6 is an illustration according to the view of the back light unit of sixth embodiment of the invention.

Back light unit according to sixth embodiment of the invention is similar with the 3rd embodiment shown in Figure 3.Yet, comprise an independent light source group according to the central light source group in the back light unit of sixth embodiment of the invention, and this independent light source group, promptly the first light source group LG1 arranges along the center line that bottom 310 is divided into left and right sides two halves.

All the other structure and the 3rd embodiment the same.

Therefore, from the explanation of the 3rd embodiment, obtain the details of all the other structures with may be obvious that.

The 7th embodiment

Fig. 7 is an illustration according to the view of the back light unit of seventh embodiment of the invention.

Back light unit according to seventh embodiment of the invention is similar with first embodiment shown in Figure 1.Yet in the back light unit according to seventh embodiment of the invention, the light source L that adjacent light source group comprises arranges by zig-zag fashion, as shown in Figure 7.In other words, move the light source L that each odd number light source group comprises, make the lower limb of their more close bottoms 310 compared with the light source L that each even number light source group comprises.

The 8th embodiment

Fig. 8 is an illustration according to the view of the back light unit of eighth embodiment of the invention.

Back light unit according to eighth embodiment of the invention is similar with second embodiment shown in Figure 2.Yet in the back light unit according to eighth embodiment of the invention, the light source L that adjacent light source group comprises arranges by zig-zag fashion, as shown in Figure 8.In other words, move the light source L that each odd number light source group comprises, make the right hand edge of their more close bottoms 310 compared with the light source L that each even number light source group comprises.

All the other structure and second embodiment the same.Therefore, from the explanation of second embodiment, obtain the details of all the other structures with may be obvious that.

The 9th embodiment

Fig. 9 is an illustration according to the view of the back light unit of ninth embodiment of the invention.

Back light unit according to ninth embodiment of the invention is similar with the 3rd embodiment shown in Figure 3.Yet in the back light unit according to ninth embodiment of the invention, the light source L that adjacent light source group comprises arranges by zig-zag fashion, as shown in Figure 9.In other words, move the light source L that each odd number light source group comprises, make the lower limb of their more close bottoms 310 compared with the light source L that each even number light source group comprises.

All the other structure and the 3rd embodiment the same.Therefore, from the explanation of the 3rd embodiment, obtain the details of all the other structures with may be obvious that.

The tenth embodiment

Figure 10 is an illustration according to the view of the back light unit of tenth embodiment of the invention.

Back light unit according to tenth embodiment of the invention is similar with the 3rd embodiment shown in Figure 3.Yet in the back light unit according to tenth embodiment of the invention, the light source L that adjacent light source group comprises arranges by zig-zag fashion, as shown in figure 10.In other words, move the light source L that each odd number light source group comprises, make the left hand edge of their more close bottoms 310 compared with the light source L that each even number light source group comprises.

The 11 embodiment

Figure 11 is an illustration according to the view of the back light unit of eleventh embodiment of the invention.

Back light unit according to eleventh embodiment of the invention is similar with the 4th embodiment shown in Figure 4.Yet in the back light unit according to eleventh embodiment of the invention, the light source L that adjacent light source group comprises arranges by zig-zag fashion, as shown in figure 11.In other words, move the light source L that each odd number light source group comprises, make the lower limb of their more close bottoms 310 compared with the light source L that each even number light source group comprises.

All the other structure and the 4th embodiment the same.Therefore, from the explanation of the 4th embodiment, obtain the details of all the other structures with may be obvious that.

The 12 embodiment

Figure 12 is an illustration according to the view of the back light unit of twelveth embodiment of the invention.

Back light unit according to twelveth embodiment of the invention is similar with the 5th embodiment shown in Figure 5.Yet in the back light unit according to twelveth embodiment of the invention, the light source L that adjacent light source group comprises arranges by zig-zag fashion, as shown in figure 12.In other words, move the light source L that each odd number light source group comprises, make the right hand edge of their more close bottoms 310 compared with the light source L that each even number light source group comprises.

All the other structure and the 5th embodiment the same.Therefore, from the explanation of the 5th embodiment, obtain the details of all the other structures with may be obvious that.

The 13 embodiment

Figure 13 is an illustration according to the view of the back light unit of thirteenth embodiment of the invention.

Back light unit according to thirteenth embodiment of the invention is similar with the 6th embodiment shown in Figure 6.Yet in the back light unit according to thirteenth embodiment of the invention, the light source L that adjacent light source group comprises arranges by zig-zag fashion, as shown in figure 13.In other words, move the light source L that each odd number light source group comprises, make the top edge of their more close bottoms 310 compared with the light source L that each even number light source group comprises.

All the other structure and the 6th embodiment the same.Therefore, from the explanation of the 6th embodiment, obtain the details of all the other structures with may be obvious that.

The 14 embodiment

Figure 14 is an illustration according to the view of the back light unit of fourteenth embodiment of the invention.

Back light unit according to fourteenth embodiment of the invention is similar with the 6th embodiment shown in Figure 6.Yet in the back light unit according to fourteenth embodiment of the invention, the light source L that adjacent light source group comprises arranges by zig-zag fashion, as shown in figure 14.In other words, move the light source L that each odd number light source group comprises, make the right hand edge of their more close bottoms 310 compared with the light source L that each even number light source group comprises.

Described light source L is a spot light in conjunction with the first to the 14 embodiment.For each light source L, can use light emitting diode (LED).Particularly, each light source L is the light source of emission white light.In this case, for each light source L, can use light-emitting area to scribble the blue led of phosphorus.Perhaps, for each light source L, can use the three-color LED of integrated morphology with red, green and blue look LED.

In fact, each light source has the packing forms that comprises above-mentioned LED and be used for driving the circuit of this LED.

Simultaneously, although describe for convenient, the number of having described light source in the number of light source group and each light source group respectively is the numerical value of determining, yet they are variable.

According to the present invention, because the spacing between the adjacent light source group increases to the relative two edges of bottom 310 gradually from the core of bottom 310, so when reducing the number of light source L, compare, can guarantee the gray scale of cold-cathode fluorescence lamp (CCFL) with regular situation.Thereby the brightness deterioration that can avoid the decreased number owing to light source L to cause has reduced manufacturing cost simultaneously.

Simultaneously, in order to compensate the brightness deterioration that is caused by light source L decreased number, the electric current that offers light source L can increase to the relative two edges of bottom 310 gradually from the core of bottom 310.Like this, obtain uniform luminance, make the core be arranged in bottom 310 light source L brightness and to be arranged in the brightness of light source L at edge of bottom 310 equal.

In other words, provide by the light source L that gives the edge be arranged in bottom 310 and to compare the magnitude of current that has increased with the light source L of the core that is arranged in bottom 310, can remedy the brightness deterioration that causes owing to light source L decreased number.

The 15 embodiment

Figure 15 is an illustration according to the view of the back light unit of fifteenth embodiment of the invention.Figure 16 is for describing the chart of the spacing between the adjacent light source in each light source group shown in Figure 15.

As shown in figure 15, comprise the bottom 310 that is formed with a plurality of light source group LG1 to LG7 according to the back light unit of fifteenth embodiment of the invention, each light source group LG1 to LG7 comprises a plurality of light source L1 to L24 that arrange in one direction.Spacing among each light source group LG1 to LG7 between the adjacent light source increases to the relative two edges of bottom 310 gradually from the core of bottom 310, reduces gradually then.

Light source L1 to L24 among each light source group LG1 to LG7 aims at along the length direction (being X-direction) on the long limit of bottom 310.Light source group LG1 to LG7 with above-mentioned layout arranges along the length direction (being Y direction) of the minor face of bottom 310.

The light source L1 to L24 that adjacent light source group comprises arranges by zig-zag fashion.In other words, move the light source L1 to L24 that each odd number light source group comprises, the light source L1 to L24 that they and each even number light source group are comprised compares the right hand edge of more close bottom 310.

Among the included light source L of each light source group LG1 to LG7, has identical spacing dy between the adjacent light source L.Light source group LG1 to LG7 comprises the same number of light source L1 to L24.The number of light source group can freely change.

Especially, the spacing of the light source L1 to L24 that each light source group LG1 to LG7 is included increases to the relative two edges of bottom 310 gradually from the core of bottom 310, reduces gradually then.Below will make a more detailed description this.Because the spacing of light source L1 to L24 increases in an identical manner or reduces among all light source group LG1 to LG7, so will only provide following description in conjunction with the first light source group LG1.Here, the spacing of light source L1 to L24 can be represented the distance between the adjacent light source, or the distance between the core of adjacent light source.In the 15 embodiment, the spacing of light source L1 to L24 is represented the distance between the core of adjacent light source.

The first light source group LG1 can be divided into the central light source that is arranged in bottom 310 cores, be arranged in a plurality of first peripheral light source between one of the relative two edges of central light source and bottom 310, and be arranged in a plurality of second peripheral light source between another edge of central light source and bottom 310.

Central light source comprises and being arranged as from two nearest light sources of the core of bottom 310.In other words, central light source comprises and being arranged as from the nearest first light source L1 of a side of the core of bottom 310 with from the nearest secondary light source L2 of opposite side of the core of bottom 310.

The first peripheral light source comprises the light source L3 to L13 between the left hand edge that is arranged in central light source left side and bottom 310.On the other hand, the second peripheral light source comprises the light source L14 to L24 between the right hand edge that is arranged in central light source right side and bottom 310.

The spacing of light source L1 to L24 increases to the left hand edge of bottom 310 gradually from the core of bottom 310, reduces gradually then.Equally, the spacing of light source L1 to L24 increases to the right hand edge of bottom 310 gradually from the core of bottom 310, reduces gradually then.

For example, shown in Figure 15 and 16, the spacing of light source L1 to L24 increases gradually from the first light source L1 to the, 12 light source L12 in each light source group, reduces gradually from the 12 light source L12 to the 13 light source L13 then.The spacing of light source L1 to L24 also increases gradually from secondary light source L2 to the 23 light source L23 in each light source group, reduces gradually from the 23 light source L23 to the 24 light source L24 then.

Figure 17 comprises respectively the chart of the comparing result of the back light unit of the light source of layout differently for showing.

A, B, C and D type back light unit have been shown among Figure 17.

Each A, B, C and D type back light unit comprise light source L1 to L24 and the bottom 310 with structure identical with Figure 15.

Yet A type back light unit is manufactured into the light source that makes in each light source group and has identical spacing, has different spacings but B, C are manufactured into the light source that makes in each light source group with D type back light unit.C type back light unit is corresponding to the back light unit of the 15 embodiment shown in Figure 15.The light source L1 to L24 that B and D type back light unit comprise in each light source group increases to the relative two edges of bottom 310 gradually from the core of bottom 310, reduces this then gradually and has on the one hand and the identical feature of C type back light unit.It is different on the one hand that B, C change different this with D type back light unit at its space between light sources.

Back light unit is applied on 47 inches liquid crystal panels, and based on observed image on liquid crystal panel, the comparing result that obtains back light unit is as follows.

The gray scale of liquid crystal panel central part office is represented in central point brightness.This numerical value is higher more satisfactory.In A, B, C and D type back light unit, the Type B back light unit has presented the highest value in the central point luminance test.In other words, in the central point luminance test, the Type B back light unit has presented result par excellence.

When the central point brightness of hypothesis A type back light unit is 100, brightness ratio has presented B, C and the central point brightness separately of the D type back light unit percentage with respect to the central point brightness of A type back light unit.This numerical value is higher more satisfactory.In A, B, C and D type back light unit, the Type B back light unit has presented the highest numerical value in the brightness ratio test.In other words, in the brightness ratio test, the Type B back light unit has presented result par excellence.

Liquid crystal panel evenly is divided into a plurality of viewing areas, and brightness uniformity has been represented the ratio (highest brightness value/minimum brightness value) of brightness with the brightness of the viewing area that presents the minimum brightness value of the viewing area that presents highest brightness value.This numerical value is low more satisfactory.In this test, liquid crystal panel evenly is divided into 128 viewing areas.In A, B, C and D type back light unit, A type back light unit has presented minimum in the brightness uniformity test.In other words, in the brightness uniformity test, A type back light unit has presented result par excellence.

The surface measurement result represents the remarkable degree of brightness uniformity.A and Type B back light unit have presented good brightness uniformity.On the other hand, C and D type back light unit have presented bad brightness uniformity." PM-1234 " expression is used for the instrument of surface measurement.

Luminance picture has presented the visual brightness uniformity.Because A and C type back light unit have presented good brightness uniformity, so used the light that uniform luminance is sent on the whole surface of the display part on the liquid crystal panel of A or C type back light unit.Yet, on the liquid crystal panel of having used B or D type back light unit, because B and D type back light unit have presented bad brightness uniformity, so the core of display part is compared the light that sends high brightness with other parts.As a result, the central part office of display part produces bright line.

The chart of the brightness of the light that Figure 18 sends for the liquid crystal panel of describing A, B, C and the D type back light unit use Figure 17 respectively.

The core of each liquid crystal panel is corresponding to the core of bottom 310.The left hand edge of each liquid crystal panel is corresponding to the left hand edge of bottom 310.The right hand edge of each liquid crystal panel is corresponding to the right hand edge of bottom 310.

According to above-mentioned test, to compare with C type back light unit, A type back light unit has presented high brightness uniformity, but has presented low brightness ratio.B and D type back light unit have the problem of the core generation bright line of display floater.Therefore, according to the result of collective of above-mentioned test, can find out that C type back light unit is best back light unit.

Although not shown, can have the feature identical with the 15 embodiment according to the back light unit of the first to the 14 embodiment.

In other words, in the situation of Fig. 1 to 14, the spacing of adjacent light source group can increase to the relative two edges of bottom 310 gradually from the core of bottom 310, reduces gradually then.

In each case, the light source group comprises the central light source group of the core that is arranged in bottom 310, be arranged in a plurality of first peripheral light source group between the edge of central light source group and bottom 310, and be arranged in a plurality of second peripheral light source group between another edge of central light source group and bottom 310.

Spacing in the central light source group and the first peripheral light source group between the adjacent light source group increases to an edge of bottom 310 gradually from the core of bottom 310, reduces gradually then.Equally, the spacing in the central light source group and the second peripheral light source group between the adjacent light source group increases to another edge of bottom 310 gradually from the core of bottom 310, reduces gradually then.

The central light source group comprises and is arranged as from the nearest first central light source group of a side of the core of bottom 310 and is arranged as the second nearest central light source group of opposite side from the core of bottom 310.

The light source that each light source group comprises is aimed at along the length direction of the minor face of bottom 310.The light source group comprises the light source of similar number.Spacing between the light source in correspondence with each other that adjacent light source group comprises respectively increases to the relative two edges of bottom 310 gradually from the core of bottom 310, reduces gradually then.In the light source that each light source group comprises, have identical spacing between adjacent light source, perhaps, the spacing of the light source that each light source group comprises can increase gradually, reduces gradually then, as the 15 embodiment.

Arrange that by another kind of the light source that each light source group comprises is aimed at along the length direction on the long limit of bottom 310.In this case, the spacing between the light source in correspondence with each other that adjacent light source group comprises respectively increases to the relative two edges of bottom 310 gradually from the core of bottom 310, reduces gradually then.

Arrange that by another the light source that each light source group comprises is aimed at along the length direction of the minor face of bottom 310.In this case, the light source group comprises the light source of similar number.Spacing between the light source in correspondence with each other that adjacent light source group comprises respectively increases to the two edges of bottom 310 gradually from the core of bottom 310, reduces gradually then.Perhaps, the spacing between the adjacent light source that each light source group comprises can increase to the relative two edges of bottom 310 gradually from the core of bottom 310, reduces gradually then.

Simultaneously, the distance between the core of the light source in correspondence with each other that can comprise respectively of the spacing between the adjacent light source group of the first to the 14 embodiment corresponding to adjacent light source group.

Having any back light unit of above-mentioned layout can be assemblied on liquid crystal display (LCD) equipment.

Figure 19 is an illustration is equipped with view according to the LCD equipment of the back light unit of exemplary embodiment of the present invention.

With reference to Figure 19, comprise back light unit 300, liquid crystal panel 390, supportive body 380 and top cover 400 according to the LCD equipment of exemplary embodiment of the present invention.

Back light unit 300 can by shown in Fig. 1 to 14 according to any configuration in the back light unit of the present invention.

Back light unit 300 is included in the bottom 310 that its relative transverse ends is opened wide, be installed in a plurality of light source L on the bottom surface of this bottom 310, be connected to the sidepiece support 340a and the 340b of the relative transverse ends of opening wide of bottom 310 respectively,

sidepiece support

340a and 340b are used for reflecting the light that is sent by light source L.

Light source L is installed on the printed circuit board (PCB) (PCB) 360.The drive current that each light source L receives from inverter by corresponding PCB 360, luminous thus.

Plane reflection member 330 is arranged on the bottom 310.Plane reflection member 330 is formed with a plurality of holes, and each light source L can extend by these holes.Plane reflection member 330 covers PCB 360 and only allows luminous light source L outstanding from this plane reflection member 330 by the hole.Plane reflection member 330 plays to spread widely the some light beam from light source L emission.

The optical component of being made up of diffuser plate and a plurality of optical sheet 350 is arranged in bottom 310 tops.Diffuser plate spreads the light from light source L emission on the whole zone of liquid crystal panel 390.

Liquid crystal panel 390 is included in the transistor (TFT) array substrate and the color filter array substrate of assembling under the opposed facing state.Liquid crystal panel 390 also comprises a plurality of distance piece (not shown) that are used for keeping the cell gap expected between two array base paltes, and by the liquid crystal layer (not shown) that is filled with in the liquid crystal spatial that distance piece limited.

Color filter array substrate comprises a plurality of filter, a plurality of public electrode and a plurality of black matrix".Perhaps, public electrode can be formed on the transistor (TFT) array substrate.

Transistor (TFT) array substrate comprises a plurality of thin film transistor (TFT)s (TFT), and a plurality of thin film transistor (TFT)s (TFT) are formed in the zone that is limited by many data wire (not shown) and many gate line (not shown) separately.Each TFT is connected to a corresponding data wire and a corresponding gate line.Transistor (TFT) array substrate also comprises the liquid crystal cells (not shown) of the TFT that is connected to separately.

Supportive body 380 is connected on the bottom 310.Having rectangular frame structure is secured on supportive body 380 and the bottom 310 with the top cover 400 at the edge that supports liquid crystal panel 390.

Bottom 310 is connected with supportive body 380, makes bottom 310 be used from the effect of the base of ccontaining back light unit 300.

The front surface edge of the liquid crystal panel 390 of top cover 400 package arrangement on bottom 310 and the transverse ends of bottom 310.In order to realize this function, top cover 400 comprises the planar section of the non-display area (being the edge of liquid crystal panel 390) that is used to cover the liquid crystal panel 390 except that the viewing area of liquid crystal panel 390, and the marginal portion that is used to encapsulate the transverse ends of bottom 310 from described planar section vertical curve.

Simultaneously, for making the central point brightness of relevant back light unit increase, the position of the light source of each above-mentioned the first to the 15 embodiment can be adjusted in the following manner.

Back light unit shown in Figure 20 has the identical layout of back light unit with Fig. 3 of illustration the 3rd embodiment.

From a plurality of light sources shown in Figure 20, will be spaced apart with the distance of " a " or " b " with the edge of the outermost light source of each adjacent layout in edge of bottom 310 and bottom 310.Particularly, will open with the core of the outermost light source Le of each adjacent layout in turning of bottom 310 and the marginating compartment in order to limit the bottom turning of bottom 310, on X-direction " a " respectively represents spacing distance with " b " on Y direction.On the other hand, the outermost light source between the outermost light source Le that the bottom corner that the same edge by bottom 310 limits arranges, spaced apart with the edge of bottom 310 with the distance of " a " or " b ".

Can central point brightness be increased.Hereinafter, be the outside spacing of X-axis with " a " value defined, " b " value defined is the outside spacing of Y-axis.

Increasing the outside spacing of X or Y-axis means the central point of outermost light source to bottom 310 is moved.Like this, remaining is arranged in the central point that light source within the outermost light source scope also is moved toward bottom 310, and the distance of central point that mobile distance and outermost light source are shifted to bottom 310 is identical.Therefore, be arranged in the central point that all light source L on the bottom 310 shift to bottom 310.

In other words, as shown in figure 21, when the Y-axis center line is moved to the left, it is moved down towards the X-axis center line at the light source L on the first quartile that will be arranged in bottom 310.Being arranged in light source L on second quadrant of bottom 310 when the Y-axis center line moves right, it is moved down towards the X-axis center line., when the Y-axis center line moves right, it is moved up towards the X-axis center line at the light source L on the third quadrant that will be arranged in bottom 310.Light source L on the four-quadrant that will be arranged in bottom 310 moves up it when the Y-axis center line is moved to the left towards the X-axis center line.Therefore, be arranged in the central point that all light source L on the bottom 310 shift to bottom 310.

For example, spacing has increased " k " by " a " when the X-axis outside, and the outside spacing of Y-axis has increased " k " by " b ", and as shown in figure 22, the area of light source region 800 reduces.Because the number that is arranged in the light source L on the light source region 800 is before the area of light source 800 reduces and constant afterwards, so the intensity height of the intensity of light source L before after the area of light source region 800 reduces, reducing than the area of light source region 800.After the area that this means light source region 800 reduced, central point brightness increased.

Although the situation that brightness uniformity reduces because the brightness away from the core of the brightness ratio bottom 310 of core of bottom 310 is low, therefore takes place in the advantage that the outside spacing of X that has increased or Y-axis provides central point brightness to increase.In other words, central point brightness and brightness uniformity are inverse proportion each other.

Therefore, consider brightness uniformity, be necessary to adjust the outside spacing of X and Y-axis.In other words, it is more satisfactory increasing the outside spacing of X and Y-axis in appropriate brightness uniformity scope.

As mentioned above, liquid crystal panel evenly is divided into a plurality of viewing areas, brightness uniformity is represented the ratio (highest brightness value/minimum brightness value) of brightness with the brightness of the viewing area that presents the minimum brightness value of the viewing area that presents highest brightness value.In above-mentioned test, liquid crystal panel evenly is divided into 128 viewing areas.

Yet in the brightness uniformity test that is used for being provided with the outside spacing of X and Y-axis, brightness uniformity is to measure under the situation that liquid crystal panel evenly is divided into 17 viewing areas.

Hereinafter, will be described in detail the brightness uniformity measuring method.

At first, preparation is according to a back light unit of the first to the 15 embodiment.Increase X in this back light unit and Y-axis outside spacing thereafter.

Measure the brightness uniformity of back light unit then.When measured value in the predetermined value scope, this back light unit with the X that increased and the outside spacing of Y-axis is normally available.

Yet, when measured value does not meet the predetermined value scope, be necessary to readjust the outside spacing of X and Y-axis.

The outside spacing of X and Y-axis also is subjected to the influence of the light path of back light unit.The light path of back light unit represents that bottom surface (inner surface of bottom is equipped with the PCB 360 of Figure 19 on it) from bottom is to the diffusion sheet distance of (form in a plurality of diffusion sheets of optical component 350 of Figure 19 and be arranged as from the nearest diffusion sheet of bottom).When light path increases, can increase the outside spacing of X and Y-axis.That is to say that light path exerts an influence to the increase nargin of X and the outside spacing of Y-axis.

Said external spacing method of adjustment also is applicable to conventional back light unit, has identical spacing (X and Y-axis spacing) between the adjacent light source in the light source wherein.

Simultaneously, the outside spacing of X and Y-axis can equal 1/2 of two spacings between adjacent light source.For example, in layout according to first embodiment shown in Figure 1,1/2 of the Y-axis spacing dy that the outside spacing of Y-axis equals to fix.On the other hand, the outside spacing of X-axis equals 1/2 of maximum the 5th spacing dx5 or ten pitch dx10.Similarly, according to the arrangement of second embodiment shown in Figure 2,1/2 of the X-axis spacing dx that the outside spacing of X-axis equals to fix.On the other hand, the outside spacing of Y-axis equals 1/2 of maximum the 3rd spacing dy3 or the 6th spacing dx6.

Be applicable to LCD equipment shown in Figure 19 with reference to the described back light unit of Figure 20 to 22.

Under the situation that does not break away from the spirit or scope of the present invention, can carry out various modifications and variations in the present invention, this is conspicuous for one of ordinary skill in the art.Therefore, the invention is intended to cover fall in claims and the equivalency range thereof to all modifications of the present invention and variation.

Claims

1. back light unit comprises:

Be formed with the bottom of a plurality of light source groups, each described light source group comprises a plurality of light sources of arranging in one direction,

Has spacing between the adjacent light source group in wherein said a plurality of light source group, this spacing increases to the relative two edges of described bottom gradually from the core of described bottom, and the electric current that offers described light source increases to the relative two edges of described bottom gradually from the core of described bottom.

2. back light unit according to claim 1 is characterized in that:

Described light source group comprises the central light source group of the core that is arranged in described bottom, be arranged in a plurality of first peripheral light source group between the edge of described central light source group and described bottom, and be arranged in a plurality of second peripheral light source group between another edge of described central light source group and described bottom;

Have between the adjacent light source group in the described central light source group and the described first peripheral light source group from the core of described bottom a spacing that the edge increases gradually to described bottom; And

Has the spacing that increases gradually to another edge of described bottom from the core of described bottom between the adjacent light source group in the described central light source group and the described second peripheral light source group.

3. back light unit according to claim 2 is characterized in that, described central light source group comprises:

Be arranged as the first nearest central light source group of a side from the core of described bottom; And

Be arranged as the second nearest central light source group of opposite side from the core of described bottom.

4. back light unit according to claim 2 is characterized in that:

The light source that each described light source group comprises is aimed at along the length direction of the minor face of described bottom;

Described light source group has the light source of similar number;

The corresponding light source that adjacent light source group in the described light source group comprises respectively has the spacing that increases gradually to the relative two edges of described bottom from the core of described bottom; And

The light source that each described light source group comprises has identical spacing.

5. back light unit according to claim 2 is characterized in that:

The light source that each described light source group comprises is aimed at along the length direction on the long limit of described bottom;

Described light source group has the light source of similar number; And

The corresponding light source that adjacent light source group in the described light source group comprises respectively has the spacing that increases gradually to the relative two edges of described bottom from the core of described bottom.

6. back light unit according to claim 2 is characterized in that:

Described light source group has the light source of similar number;

Has the spacing that increases gradually to the relative two edges of described bottom from the core of described bottom between the adjacent light source in the light source that each described light source group comprises.

7. back light unit according to claim 6 is characterized in that, the spacing of adjacent light source has identical spacing increment rate in the spacing of the corresponding described light source that adjacent described light source group comprises respectively and each described light source group.

8. back light unit according to claim 7 is characterized in that, described spacing increment rate is 0.2mm.

9. back light unit according to claim 6 is characterized in that, the spacing of adjacent light source has different spacing increment rates respectively in the spacing of the corresponding light source that adjacent described light source group comprises respectively and each described light source group.

10. back light unit according to claim 6 is characterized in that, the light source that adjacent described light source group comprises is arranged by zig-zag fashion.