CN202209589U

CN202209589U - Backlight and liquid crystal display

Info

Publication number: CN202209589U
Application number: CN2011203046935U
Authority: CN
Inventors: 李友; 马青
Original assignee: Beijing BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2011-08-19
Filing date: 2011-08-19
Publication date: 2012-05-02
Anticipated expiration: 2021-08-19

Abstract

The utility model relates to the production technical field of a liquid crystal display (LCD), especially a backlight and an LCD used for improving the phenomenon of the uneven brightness of an LCD. The backlight comprises a groove and the groove is embedded in the diagonal direction of the illuminated surface of a light guide plate. An LED is arranged in the groove according to an arrangement mode set in advance. Due to the adoption of the backlight, the light emitted by the LED is projected dispersely. When the light reaches a light extracting surface after being refracted repeatedly in the light guide plate, the light is still in a disperse state. Therefore, the phenomenon of the uneven brightness of a display is improved. Meanwhile, when the light emitted by the LED scatters in the diagonal direction of the light guide plate, the light path of the light in the light guide plate is shortened. Therefore, the occurrence of color cast phenomena due to the excessively large light path is reduced. When the Led is arranged in the diagonal line of the light guide plate, the narrow frame of the display can be conveniently designed.

Description

A kind of backlight and LCD

Technical field

The utility model relates to the liquid crystal display production technical field, relates in particular to a kind of backlight and LCD.

Background technology

Comprise the backlight that can send white light in the LCD; Comprise a plurality of light emitting diodes (Light Emitting Diode that light source is provided in the backlight; LED) and LGP; As shown in Figure 1, the mode with straight line is arranged side by side on the incidence surface 12 position for example shown in Figure 1 to a plurality of LED11 along a limit of the incidence surface 12 of LGP.The light that LED11 sends reflects away through exiting surface 13; Vertical sectional drawing of backlight is as shown in Figure 2 in the prior art; Comprising: the optical film material 21 that covers the upper bottom surface of LGP 25; Cover the reflectance coating 22 of the bottom surface of LGP 25; LED11 links to each other with printed circuit board 23, and said printed circuit board 23 sticks on the backboard 24 of backlight through double faced adhesive tape.

But the inventor finds; Because in the prior art is that LED11 is arranged on the incidence surface 12 with linear fashion along the limit of the incidence surface 12 of LGP 25; With position shown in Figure 1 is example; The light that sends as LED11 is refracted to 13 last times of exiting surface from the incidence surface 12 of LGP 25, because light need be through the refraction once more than in LGP 25 inside, so light very big light path of needs when LGP 25 internal transmission; Simultaneously; Because all LED arrange with linear fashion; Make the brightness of the position that distance L ED is nearer be far longer than brightness away from the LED position; Therefore, on the exiting surface 13 of LGP 25, cause the phenomenon of brightness irregularities, also can on LCD, cause the phenomenon of brightness irregularities simultaneously.

The utility model content

The utility model embodiment provides a kind of backlight, is used to improve the phenomenon of brightness irregularities on the LCD.

A kind of backlight, said backlight comprises a plurality of LED and LGP, said backlight comprises:

Groove, said groove are embedded on the diagonal of incidence surface of said LGP;

Said LED is placed in the said groove according to the modes of emplacement that is provided with in advance.

It is thus clear that; A kind of backlight that adopts the utility model embodiment to provide, this backlight can be placed on LED in the groove on the diagonal of incidence surface of LGP according to the modes of emplacement that is provided with in advance, and this modes of emplacement can make LED carry out the rotation on the different directions; Make the light that is produced disperse projection; When these light still become dispersity through repeatedly reflecting when the back arrives exiting surface in LGP, therefore, can improve the phenomenon of the brightness disproportionation of display; Simultaneously,, can reduce the light path of light in LGP, thereby reduce the color offset phenomenon that causes too greatly because of light path when the light of LED scatters out from the LGP diagonal; Simultaneously,, can improve the utilization rate of light owing to the minimizing of light path, with the number of minimizing LED, thus the cost of attenuating backlight; When LED is arranged on the diagonal of LGP, can conveniently carry out narrow frame design to display; When LED is arranged on the diagonal of LGP, can increases the spacing between the LED, thereby more help the heat radiation of LED.

Description of drawings

Fig. 1 is the syndeton sketch map of LGP and LED in the prior art;

Fig. 2 is the tangent plane structural representation of backlight in the prior art;

Fig. 3 is the projecting direction sketch map that has the light of maximum optical intensity when the LED journey is arranged in a straight line in the prior art;

LGP and LED's is connected the plan structure sketch map in first kind of backlight that Fig. 4 a provides for the utility model embodiment;

The displacement structure sketch map of LED and groove in first kind of backlight that Fig. 4 b provides for the utility model embodiment;

The position view of angle and spacing in first kind of backlight that Fig. 5 provides for the utility model embodiment;

The projecting direction sketch map that has the light of maximum optical intensity when LED arranges according to the modes of emplacement that is provided with in advance in first kind of backlight that Fig. 6 provides for the utility model embodiment;

The tangent plane structural representation of first kind of backlight that Fig. 7 provides for the utility model embodiment;

LGP and LED's is connected the plan structure sketch map in second kind of backlight that Fig. 8 provides for the utility model embodiment.

The specific embodiment

The utility model embodiment provides a kind of backlight; This backlight can be placed on LED in the groove on the diagonal of incidence surface of LGP according to the modes of emplacement that is provided with in advance; This modes of emplacement can make LED carry out the rotation on the different directions; Make the light that LED produced disperse projection, when these light still become dispersity through repeatedly reflecting when the back arrives exiting surface in LGP; Said incidence surface is the one side that LED is installed on the LGP, and the light-emitting area of said LED is perpendicular to said incidence surface.Preferable, when the central point of all LED is on the diagonal of the incidence surface of LGP, and the light that has highlight intensity that guarantees that LED produced can improve the phenomenon of the brightness disproportionation of display when meeting the aplanatism principle well; Equivalent optical path when the light that has highlight intensity that said aplanatism principle is sent for all LED arrives on the same plane.Simultaneously, when the light of the LED diagonal from the incidence surface of LGP scatters out, can reduce the light path of light in LGP, thereby reduce the color offset phenomenon that causes too greatly because of light path; Simultaneously,, can improve the utilization rate of light owing to the minimizing of light path, with the number of minimizing LED, thus the cost of attenuating backlight; When LED is arranged on the diagonal of LGP, can conveniently carry out narrow frame design to display; When LED is arranged on the diagonal of LGP, can increases the spacing between the LED, thereby more help the heat radiation of LED.Below with the specific embodiment introduction.

Embodiment one:

The utility model embodiment one provides first kind of backlight; The arrangement mode of LED11 in this backlight on the incidence surface of LGP 25 is shown in Fig. 4 a; Comprising a plurality of identical groove on the diagonal of the incidence surface that is embedded in said LGP 25 41 and the LED11 that is placed in the groove 41, the number of LED11 is at least three, and the number of said groove 41 equates with the number of said LED11; And place a LED11 in each groove 41, shown in Fig. 4 b; All LED11 are placed in the said groove 41 according to the modes of emplacement that is provided with in advance; It is the position of the putting position decision groove of LED11; The central point that said modes of emplacement makes all LED point-blank.

Preferable, as shown in Figure 5, the angle ranging from the angle 52 that the center line MM of two adjacent LED11 is become; Air line distance between the central point that said spacing 51 is two adjacent LED 11; Said spacing 51 and angle can guarantee to discharge the light 31 that all LED11 of postpone send has highlight intensity and meet aplanatism principle as shown in Figure 6; The said light 31 that has highlight intensity is positioned at the centermost of LED11; Preferably, the central point of all LED can satisfy the aplanatism principle so better on the diagonal of the incidence surface of LGP 25.As shown in Figure 3, the equivalent optical path the when light that has highlight intensity 31 that said aplanatism principle is sent for all LED11 arrives on the same plane, said light path is the length of light 31; Preferable, the spacing between the light 31 of the highlight intensity of adjacent LED lamp equates, shown in Fig. 6 intermediate reach 62, so that light is more even;

Preferable, the placement location of groove is following:

Spacing between the central point of every adjacent two grooves equals the spacing between two adjacent LED corresponding with said two grooves; The length direction angulation of two whenever adjacent grooves equals adjacent two the LED center line angulations corresponding with said two grooves;

The sectional drawing of the structure around the LED11 of this backlight incidence surface is as shown in Figure 7, comprising: optical film material 21, LGP 25, reflectance coating 22, LED11, printed circuit board (PCB) 23, double faced adhesive tape 71 and backboard 24, the concrete structure of this backlight is following:

Confirm the position of all LED11 at incidence surface according to angle 52 and spacing 51; And confirm the position of groove 41 according to this position; The big I of said groove 41 is big or small identical with LED11's; The back side of LED11 is linked to each other with printed circuit board 23, and said printed circuit board (PCB) 23 covers on the said groove 41, and printed circuit board (PCB) 23 sticks on the backboard 24 through double faced adhesive tape 71; Said printed circuit board 23 is close to reflectance coating 22, or can be on reflectance coating 22;

Preferable, LED11 and leaves predefined spacing between the side of the inboard of the light-emitting area of said LED11 and groove 41 in groove 41, and this predefined spacing helps heat radiation.This predefined spacing can be preferably 0.1 millimeter to 0.5 millimeter, to guarantee the heat that LED11 sends LGP 25 inner materials is changed.

Preferable, LED etc. is placed in the groove, can guarantee that the light transmittance of LED is big as much as possible, so that the utilization ratio of light is higher.

Embodiment two:

As shown in Figure 8; The utility model embodiment provides second kind of backlight; The difference of first kind of backlight that said second kind of backlight and embodiment are a kind of is: comprise a groove 81 on the diagonal of incidence surface of the LGP 25 that is embedded in said backlight in said second kind of backlight; The modes of emplacement of LED11 in groove 81, promptly required angle and spacing can be referring to embodiment one;

The utility model embodiment also provides a kind of LCD, and said LCD comprises the foregoing description one and embodiment two described backlights.

Preferable, among above-mentioned all embodiment, the central point setting of all LED can make the light that LED produced disperse projection as much as possible point-blank, therefore, can improve the phenomenon of the brightness disproportionation of display better; Perhaps; The central point of all LED is not provided with point-blank; But near the diagonal of the incidence surface of LGP 25, offset some small amount is arranged, as long as satisfy the aplanatism principle, the equivalent optical path the when light that has highlight intensity that promptly all LED send arrives on the same plane gets final product.

In sum, beneficial effect:

The utility model embodiment provides a kind of backlight and LCD; This backlight can be placed on LED in the groove on the diagonal of incidence surface of LGP 25 according to the modes of emplacement that is provided with in advance; The central point that said modes of emplacement makes all LED point-blank; This modes of emplacement can guarantee that the light that LED produces meets the aplanatism principle, can make the light that LED produced disperse projection as much as possible simultaneously; Therefore, can improve the phenomenon of the brightness disproportionation of display; Simultaneously,, can reduce the light path of light, thereby reduce the color offset phenomenon that causes too greatly because of light path 25 li of LGPs when the light of LED scatters out from LGP 25 diagonal; Simultaneously,, can improve the utilization rate of light owing to the minimizing of light path, with the number of minimizing LED, thus the cost of attenuating backlight; When LED is arranged on the diagonal of LGP 25, can conveniently carry out narrow frame design to display; When LED is arranged on the diagonal of LGP 25, can increases the spacing between the LED, thereby more help the heat radiation of LED.

Obviously, those skilled in the art can carry out various changes and modification to the utility model and not break away from the spirit and the scope of the utility model.Like this, belong within the scope of the utility model claim and equivalent technologies thereof if these of the utility model are revised with modification, then the utility model also is intended to comprise these changes and modification interior.

Claims

1. backlight, said backlight comprises a plurality of LED and LGP, it is characterized in that, also comprises:

At least three said LED are placed in the said groove.

2. backlight as claimed in claim 1 is characterized in that, said incidence surface is the one side that LED is installed on the LGP, and the light-emitting area of said LED is perpendicular to said incidence surface.

3. backlight as claimed in claim 1 is characterized in that, has predefined spacing and angle between per two adjacent LED; Said spacing is the distance between the central point of per two adjacent LED; The angle ranging from the angle that center line became of per two adjacent LED; Said spacing and angle make the light that has highlight intensity that all LED sent meet the aplanatism principle.

4. backlight as claimed in claim 3 is characterized in that, the equivalent optical path the when light that said aplanatism principle is used to represent to send said highlight intensity arrives same plane.

5. backlight as claimed in claim 3 is characterized in that, the number of said groove equates with the number of said LED, places a LED in each groove.

6. backlight as claimed in claim 5 is characterized in that, the spacing between the central point of every adjacent two grooves equals the spacing between two adjacent LED corresponding with said two grooves;

The length direction angulation of two whenever adjacent grooves equals adjacent two the LED center line angulations corresponding with said two grooves.

7. backlight as claimed in claim 1 is characterized in that, the number of said groove is one.

8. backlight as claimed in claim 1 is characterized in that, there are predefined spacing in the light-emitting area of said LED and said groove inboard.

9. backlight as claimed in claim 1 is characterized in that said backlight comprises printed circuit board;

Said printed circuit board is connected with said LED;

Said printed circuit board covers on the said groove.

10. backlight as claimed in claim 1 is characterized in that the central point of all LED point-blank.

11. a LCD is characterized in that, comprises the arbitrary described backlight of claim 1-9.